Pathways and Molecular Mechanisms Governing LDL Receptor Regulation

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Monoclonal antibodies directed against PCSK9 promote internalization and degradation of LDLR.

“monoclonal antibodies directed against Proprotein convertase subtilisin/kexin type 9 (PCSK9) that promotes internalization and degradation of LDLR7”

• cites [7] Chaudhary R, Garg J, Shah N, Sumner A. PCSK9 inhibitors: A new era of lipid lowering therapy. World J Cardiol. 2017; 9(2): 76– 91. doi: 10.4330/wjc.v9.i2.76 28289523 PMC5329749 sourceSupported

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Statins inhibit HMG CoA reductase, the rate-limiting enzyme of de novo cholesterol synthesis.

“the Statin class of drugs inhibit 3-hydroxy-3-methylglutaryl (HMG) CoA reductase (HMGCR), the rate-limiting enzyme of de novo cholesterol synthesis5”

• cites [5] Stancu C, Sima A. Statins: mechanism of action and effects. J Cellular Molecular Medi. 2001; 5(4): 378– 387. doi: 10.1111/j.1582-4934.2001.tb00172.x PMC6740083 12067471 sourcePartly supported

  The Introduction identifies statins as HMG-CoA reductase inhibitors and calls that enzyme the principal enzyme involved in endogenous cholesterol synthesis. The “Inhibition of HMG CoA reductase” section describes its role in producing a cholesterol precursor. Our copy does not specifically establish that it is the rate-limiting enzyme. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Complete absence or defective LDLRs due to mutations in the LDLR gene cause familial hypercholesterolemia, characterized by autosomal dominant inheritance of hypercholesterolemia and premature atherosclerotic cardiovascular disease.

“Complete absence or defective LDLRs due to mutations in the LDLR gene cause FH, characterized by an autosomal dominant inheritance of hypercholesterolemia and premature ASCVD (a list of mutations can be found in Table 1)1–4.”

• cites [1] Galicia-Garcia U, Benito-Vicente A, Uribe KB, Jebari S, Larrea-Sebal A, Alonso-Estrada R, Aguilo-Arce J, Ostolaza H, Palacios L, Martin C. Mutation type classification and pathogenicity assignment of sixteen missense variants located in the EGF-precursor homology domain of the LDLR. Scientific reports. 2020; 10(1): 1727. doi: 10.1038/s41598-020-58734-9 32015373 PMC6997160 sourcePartly supported

  The Introduction (page not provided) says LDLR mutations account for approximately 80–85% of FH cases, describes mutations that eliminate or impair receptor function, and links FH to high LDL cholesterol and premature atherosclerotic disease. Our copy does not state that FH has autosomal dominant inheritance, so that part of the claim is not supported by this source. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [2] Brown MS, Goldstein JL. A receptor-mediated pathway for cholesterol homeostasis. Science. 1986; 232(4746): 34– 47. doi: 10.1126/science.3513311 3513311 sourceNot checked — no full text of the source
• cites [3] Banerjee P, Chan KC, Tarabocchia M, Benito-Vicente A, Alves AC, Uribe KB, Bourbon M, Skiba PJ, Pordy R, Gipe DA, Gaudet D, Martin C. Functional Analysis of LDLR (Low-Density Lipoprotein Receptor) Variants in Patient Lymphocytes to Assess the Effect of Evinacumab in Homozygous Familial Hypercholesterolemia Patients With a Spectrum of LDLR Activity. Arterioscler Thromb Vasc Biol. 2019; 39(11): 2248– 2260. doi: 10.1161/ATVBAHA.119.313051 31578082 PMC6818983 sourceSupported
• cites [4] Hobbs HH, Russell DW, Brown MS, Goldstein JL. The LDL receptor locus in familial hypercholesterolemia: mutational analysis of a membrane protein. Annu Rev Genet. 1990; 24: 133– 170. doi: 10.1146/annurev.ge.24.120190.001025 2088165 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The stability of a given mRNA is largely determined by the structure of its 3' untranslated region.

“The stability of a given mRNA is largely determined by the structure of its 3’ untranslated region (UTR)41.”

• cites [41] Martin KC, Ephrussi A. mRNA Localization: Gene Expression in the Spatial Dimension. Cell. 2009; 136(4): 719– 730. doi: 10.1016/j.cell.2009.01.044 19239891 PMC2819924 sourcePartly supported

  The Selective stabilization section reports that 3′UTR elements govern degradation and local protection of hsp83 mRNA and describes a similar mechanism for nanos. But it does not establish that mRNA stability generally is largely determined by 3′UTR structure. The discussion of secondary structure in Future directions concerns localization, not stability. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Ezetimibe blocks the intestinal cholesterol transporter NPC1L1 that mediates cholesterol absorption.

“Ezetimibe blocks the intestinal cholesterol transporter Niemann Pick C1-Like 1 (NPC1L1) that mediates cholesterol absorption6”

• cites [6] Garcia-Calvo M, Lisnock J, Bull HG, Hawes BE, Burnett DA, Braun MP, Crona JH, Davis HR, Dean DC, Detmers PA, Graziano MP, Hughes M, Macintyre DE, Ogawa A, O’neill KA, Iyer SPN, Shevell DE, Smith MM, Tang YS, Makarewicz AM, Ujjainwalla F, Altmann SW, Chapman KT, Thornberry NA. The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1). Proc Natl Acad Sci U S A. 2005; 102(23): 8132– 8137. doi: 10.1073/pnas.0500269102 15928087 PMC1149415 sourcePartly supported

  The Results and Discussion establish NPC1L1 as ezetimibe’s direct target and say that ezetimibe binding blocks intestinal cholesterol absorption. But the same section says it remains unresolved whether NPC1L1 is the cholesterol transporter itself or a regulatory component that indirectly affects transport. Calling it the transporter overstates the paper’s finding. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

SREBP-2 contains an NH2-terminal bHLH-Zip domain that interacts with the SRE in the LDLR gene promoter region, leading to increases in transcription and translation of LDLR protein.

“SREBP-2 contains a NH2-terminal domain with a basic-helix-loop-helix-leucine zipper (bHLH-Zip)26 that interacts with the SRE in the LDLR gene promotor region27, leading to increases in transcription and translation of LDLR protein.”

• cites [26] Brown MS, Goldstein JL. The SREBP Pathway: Regulation of Cholesterol Metabolism by Proteolysis of a Membrane-Bound Transcription Factor. Cell. 1997; 89(3): 331– 340. doi: 10.1016/S0092-8674(00)80213-5 9150132 sourceNot checked — no full text of the source
• cites [27] Hua X, Yokoyama C, Wu J, Briggs MR, Brown MS, Goldstein JL, Wang X. SREBP-2, a second basic-helix-loop-helix-leucine zipper protein that stimulates transcription by binding to a sterol regulatory element. Proc Natl Acad Sci USA. 1993; 90(24): 11603– 11607. doi: 10.1073/pnas.90.24.11603 7903453 PMC48032 sourcePartly supported

  The Abstract (p. 11603) describes an NH2-terminal bHLH-Zip motif, SREBP-2 binding to SRE-1, and activation of SRE-1-containing reporter genes; it identifies SRE-1 as an enhancer in the LDL receptor promoter. It does not report increased translation or levels of LDLR protein, and its transcription result concerns reporter genes rather than a direct measurement of LDLR expression. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

miR-128-1 is located within intron 18 of R3HDM1, and its expression is dependent on expression of its host gene.

“miR-128-1 is located within intron 18 of R3HDM1 and its expression is dependent on the expression of its host gene51.”

• cites [51] Wagschal A, Najafi-Shoushtari SH, Wang L, Goedeke L, Sinha S, deLemos AS, Black JC, Ramírez CM, Li Y, Tewhey R, Hatoum I, Shah N, Lu Y, Kristo F, Psychogios N, Vrbanac V, Lu YC, Hla T, De Cabo R, Tsang JS, Schadt E, Sabeti PC, Kathiresan S, Cohen DE, Whetstine J, Chung RT, Fernández-Hernando C, Kaplan LM, Bernards A, Gerszten RE, Näär AM. Genome-wide identification of microRNAs regulating cholesterol and triglyceride homeostasis. Nat Med. 2015; 21(11): 1290– 1297. doi: 10.1038/nm.3980 26501192 PMC4993048 sourcePartly supported

  The Results section, “MicroRNAs are linked to SNPs associated with abnormal blood lipids” (page unavailable), places miR-128-1 in intron 18 of R3HDM1. It says the two appear extensively co-expressed, suggesting a shared primary transcript, but does not establish that miR-128-1 expression depends on host-gene expression. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

hnRNP D, hnRNP I, and KSRP bind AREs in the 3'UTR, demonstrating that multiple RBPs can influence the stability of LDLR mRNA.

“These RBPs bind AREs in the 3’UTR, demonstrating that multiple RBPs can influence the stability of LDLR mRNA61.”

• cites [61] Li H, Chen W, Zhou Y, Abidi P, Sharpe O, Robinson WH, Kraemer FB, Liu J. Identification of mRNA binding proteins that regulate the stability of LDL receptor mRNA through AU-rich elements. Journal of Lipid Research. 2009; 50(5): 820– 831. doi: 10.1194/jlr.M800375-JLR200 19141871 PMC2666168 sourceSupported

It may state two separate claims as one.

HuR/ELAVL1 binds the same AREs to stabilize LDLR mRNA and increase LDLR proteins in hepatocytes.

“While these RBPs destabilize their mRNA targets leading to degradation of LDLR, human antigen R (HuR), also known as ELAV-like RNA binding protein 1 (ELAVL1), binds the same AREs to stabilize LDLR mRNA and increase LDLR proteins in hepatocytes65,66.”

• cites [65] Singh AB, Dong B, Kraemer FB, Xu Y, Zhang Y, Liu J. Farnesoid X Receptor Activation by Obeticholic Acid Elevates Liver Low-Density Lipoprotein Receptor Expression by mRNA Stabilization and Reduces Plasma Low-Density Lipoprotein Cholesterol in Mice. ATVB. 2018; 38(10): 2448– 2459. doi: 10.1161/ATVBAHA.118.311122 PMC6206879 30354208 sourceSupported
• cites [66] Yashiro T, Nanmoku M, Shimizu M, Inoue J, Sato R. 5-Aminoimidazole-4-carboxamide ribonucleoside stabilizes low density lipoprotein receptor mRNA in hepatocytes via ERK-dependent HuR binding to an AU-rich element. Atherosclerosis. 2013; 226(1): 95– 101. doi: 10.1016/j.atherosclerosis.2012.09.033 23116706 sourceNot checked — no full text of the source

It may state two separate claims as one.

The truncated 3'UTR lacks binding sites for both miR128-1 and miR-148, while the miR-185 binding site is still present.

“This truncated 3’UTR lacks binding sites for both miR128-1 and miR-14852,53,67, while the miR-185 binding site is still present54,67.”

• cites [52] Goedeke L, Rotllan N, Canfrán-Duque A, Aranda JF, Ramírez CM, Araldi E, Lin CS, Anderson NN, Wagschal A, De Cabo R, Horton JD, Lasunción MA, Näär AM, Suárez Y, Fernández-Hernando C. MicroRNA-148a regulates LDL receptor and ABCA1 expression to control circulating lipoprotein levels. Nat Med. 2015; 21(11): 1280– 1289. doi: 10.1038/nm.3949 26437365 PMC4711995 sourcePartly supported

  The Results section on LDLR activity reports two miR-148a binding sites in the LDLR 3′ UTR, supporting the premise that those sites exist. It does not establish that the particular truncated 3′ UTR lacks them, or address whether that truncation removes a miR-128-1 site. The miR-185 clause is attached to other citations, so it is not assessed against this source. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites [53] Yang M, Liu W, Pellicane C, Sahyoun C, Joseph BK, Gallo-Ebert C, Donigan M, Pandya D, Giordano C, Bata A, Nickels JT. Identification of miR-185 as a regulator of de novo cholesterol biosynthesis and low density lipoprotein uptake. Journal of Lipid Research. 2014; 55(2): 226– 238. doi: 10.1194/jlr.M041335 24296663 PMC3886661 sourcePartly supported

  The Results (page unavailable) identify miR-185 binding sites in the SREBP-2 3′UTR and report that mutating them interfered with miR-185 targeting. The paper examines the wild-type 3′UTR and point-mutated binding sites, but does not establish that a miR-185 site remains in the truncated 3′UTR described by the citing sentence. The miR-128-1 and miR-148 clause is attached to other citations, not this one. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [67] Bjornsson E, Gunnarsdottir K, Halldorsson GH, Sigurdsson A, Arnadottir GA, Jonsson H, Olafsdottir EF, Niehus S, Kehr B, Sveinbjörnsson G, Gudmundsdottir S, Helgadottir A, Andersen K, Thorleifsson G, Eyjolfsson GI, Olafsson I, Sigurdardottir O, Saemundsdottir J, Jonsdottir I, Magnusson OTh, Masson G, Stefansson H, Gudbjartsson DF, Thorgeirsson G, Holm H, Halldorsson BV, Melsted P, Norddahl GL, Sulem P, Thorsteinsdottir U, Stefansson K. Lifelong Reduction in LDL (Low-Density Lipoprotein) Cholesterol due to a Gain-of-Function Mutation in LDLR. Circ: Genomic and Precision Medicine. 2021; 14(1): e0 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

miR-27a and miR-27b are two highly similar miRNAs originating from the same seed sequence with a difference of a single nucleotide.

“The miR-27 family (miR-27a and miR-27b) are two highly similar miRNAs originating from the same seed sequence with a difference of a single nucleotide55.”

• cites [55] Alvarez ML, Khosroheidari M, Eddy E, Done SC. MicroRNA-27a decreases the level and efficiency of the LDL receptor and contributes to the dysregulation of cholesterol homeostasis. Atherosclerosis. 2015; 242(2): 595– 604. doi: 10.1016/j.atherosclerosis.2015.08.023 26318398 PMC4575910 sourceSupported

It may state two separate claims as one.

miR-148a is primarily expressed in the liver, and its expression is induced in mice and rhesus macaques fed a high fat diet.

“miR-148a is primarily expressed in the liver and expression is induced in mice and rhesus macaques fed a high fat diet51.”

• cites [51] Wagschal A, Najafi-Shoushtari SH, Wang L, Goedeke L, Sinha S, deLemos AS, Black JC, Ramírez CM, Li Y, Tewhey R, Hatoum I, Shah N, Lu Y, Kristo F, Psychogios N, Vrbanac V, Lu YC, Hla T, De Cabo R, Tsang JS, Schadt E, Sabeti PC, Kathiresan S, Cohen DE, Whetstine J, Chung RT, Fernández-Hernando C, Kaplan LM, Bernards A, Gerszten RE, Näär AM. Genome-wide identification of microRNAs regulating cholesterol and triglyceride homeostasis. Nat Med. 2015; 21(11): 1290– 1297. doi: 10.1038/nm.3980 26501192 PMC4993048 sourceSupported

It may state two separate claims as one.

A high cholesterol diet increases hepatic expression of hnRNP D in murine models, which leads to degradation of LDLR mRNA, whereas adenovirus-mediated depletion of hnRNP D decreased circulating LDL levels.

“More recently, it has been shown that high cholesterol diet increases hepatic expression of hnRNP D in murine models which in turn leads to degradation of LDLR mRNA, whereas adenovirus mediated depletion of hnRNP D decreased circulating LDL levels63.”

• cites [63] Singh AB, Kan CFK, Shende V, Dong B, Liu J. A novel posttranscriptional mechanism for dietary cholesterol-mediated suppression of liver LDL receptor expression. Journal of Lipid Research. 2014; 55(7): 1397– 1407. doi: 10.1194/jlr.M049429 24792925 PMC4076078 sourceSupported

It may state two separate claims as one.

LDLR is translocated to the Golgi network where it is glycosylated and released via vesicles to the plasma membrane, where it is recruited by Dab2 to reside within clathrin-rich pits.

“It is then translocated to the Golgi network where it is glycosylated and released via vesicles to the plasma membrane, where is it recruited by Dab281 to reside within clathrin-rich pits82–84.”

• cites [81] Maurer ME, Cooper JA. The adaptor protein Dab2 sorts LDL receptors into coated pits independently of AP-2 and ARH. Journal of Cell Science. 2006; 119(20): 4235– 4246. doi: 10.1242/jcs.03217 16984970 sourceNot checked — no full text of the source
• cites [82] Pearse BM. Clathrin: a unique protein associated with intracellular transfer of membrane by coated vesicles. Proc Natl Acad Sci USA. 1976; 73(4): 1255– 1259. doi: 10.1073/pnas.73.4.1255 1063406 PMC430241 sourceNot checked — no full text of the source
• cites [83] Anderson RGW, Brown MS, Goldstein JL. Role of the coated endocytic vesicle in the uptake of receptor-bound low density lipoprotein in human fibroblasts. Cell. 1977; 10(3): 351– 364. doi: 10.1016/0092-8674(77)90022-8 191195 sourceNot checked — no full text of the source
• cites [84] Goldstein JL, Brown MS. The LDL Receptor. ATVB. 2009; 29(4): 431– 438. doi: 10.1161/ATVBAHA.108.179564 PMC2740366 19299327 sourceSupported

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

LDLR spans the plasma membrane with a single simple transmembrane domain, lacking a GPI anchor.

“LDLR spans the plasma membrane with a single simple transmembrane domain, lacking a GPI anchor13.”

• cites [13] Südhof TC, Goldstein JL, Brown MS, Russell DW. The LDL Receptor Gene: A Mosaic of Exons Shared with Different Proteins. Science. 1985; 228(4701): 815– 822. doi: 10.1126/science.2988123 2988123 PMC4450672 sourceSupported

It may state two separate claims as one.

Goedeke et al. demonstrated that miR-27b regulates LDLR expression using luciferase reporter assays in Cos7 cells, where addition of miR-27b decreased luciferase activity, but mutation of the predicted binding sites reversed this effect.

“Goedeke et. al. demonstrated that miR-27b regulates LDLR expression using luciferase reporter assays in Cos7 cells, where addition of miR-27b decreased luciferase activity, but mutation of the predicted binding sites reversed this effect57.”

• cites [57] Goedeke L, Rotllan N, Ramírez CM, Aranda JF, Canfrán-Duque A, Araldi E, Fernández-Hernando A, Langhi C, De Cabo R, Baldán Á, Suárez Y, Fernández-Hernando C. miR-27b inhibits LDLR and ABCA1 expression but does not influence plasma and hepatic lipid levels in mice. Atherosclerosis. 2015; 243(2): 499– 509. doi: 10.1016/j.atherosclerosis.2015.09.033 26520906 PMC4975922 sourceSupported

It may state two separate claims as one.

At the cell surface, the catalytic domain of PCSK9 binds to the EGF-A repeat of the LDLR extracellular domain and the LDLR:PCSK9 complex is internalized through clathrin-coated pits.

“At the cell surface, the catalytic domain of PCSK9 binds to the EGF-A repeat of the LDLR extracellular domain and the LDLR:PCSK9 complex is internalized through clathrin-coated pits119,120.”

• cites [119] Zhang DW, Lagace TA, Garuti R, Zhao Z, McDonald M, Horton JD, Cohen JC, Hobbs HH. Binding of proprotein convertase subtilisin/kexin type 9 to epidermal growth factor-like repeat A of low density lipoprotein receptor decreases receptor recycling and increases degradation. J Biol Chem. 2007; 282(25): 18602– 18612. doi: 10.1074/jbc.M702027200 17452316 sourcePartly supported

  The Discussion (page not provided) supports PCSK9 binding to LDLR EGF-A at the cell surface, and the paper describes LDLR clustering in clathrin-coated pits and internalization. It does not identify the catalytic domain of PCSK9 as the binding region. The Discussion also says the authors could not determine whether PCSK9 accompanies LDLR into the cell, so it does not establish internalization of the LDLR:PCSK9 complex through those pits. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [120] Wang Y, Huang Y, Hobbs HH, Cohen JC. Molecular characterization of proprotein convertase subtilisin/kexin type 9-mediated degradation of the LDLR. Journal of Lipid Research. 2012; 53(9): 1932– 1943. doi: 10.1194/jlr.M028563 22764087 PMC3413232 sourcePartly supported

  The paper’s introductory passage says PCSK9 binds the LDLR’s EGF-A repeat at the cell surface, and the Results section reports that the PCSK9–LDLR complex uses clathrin-mediated endocytosis. Our copy does not specify that PCSK9’s catalytic domain is the part that binds EGF-A. No page numbers are provided for these passages. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Many mutations that cause familial hypercholesterolemia are receptor-null Class I mutations that result in no LDLR protein, while Class II mutations result in production of LDLR protein that is not properly processed.

“While many mutations that cause FH are receptor-null Class I mutations that result in no LDLR protein, Class II mutations result in production of the LDLR protein, but it is not properly processed85–87.”

• cites [85] Goldstein JL, Brown MS, Anderson RGW, Russell DW, Schneider WJ. Receptor-Mediated Endocytosis: Concepts Emerging from the LDL Receptor System. Annu Rev Cell Biol. 1985; 1(1): 1– 39. doi: 10.1146/annurev.cb.01.110185.000245 2881559 sourceNot checked — no full text of the source
• cites [86] Shu H, Chi J, Li J, Zhang W, Lv W, Wang J, Deng Y, Hou X, Wang Y. A novel indel variant in LDLR responsible for familial hypercholesterolemia in a Chinese family. Ariga H, ed. PLoS ONE. 2017; 12(12): e0189316. doi: 10.1371/journal.pone.0189316 29228028 PMC5724832 sourcePartly supported

  The Discussion says Class 1 mutations prevent detectable LDLR synthesis and Class 2 mutations impair transport of mutant LDLR through the ER. The Introduction also describes Class 2 mutations as preventing proper transport to the Golgi for receptor modification. Our copy does not establish that many FH-causing mutations are Class I. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [87] Kizhakkedath P, John A, Al-Sawafi BK, Al-Gazali L, Ali BR. Endoplasmic reticulum quality control of LDLR variants associated with familial hypercholesterolemia. FEBS Open Bio. 2019; 9(11): 1994– 2005. doi: 10.1002/2211-5463.12740 PMC6823279 31587492 sourceSupported

It may state two separate claims as one.

Normally, the γ-secretase enzyme complex is autoinhibited, and this autoinhibition is removed when substrates are cleaved extracellularly, exposing the transmembrane domain for cleavage by γ-secretase.

“Normally, the γ-secretase enzyme complex is autoinhibited, and this autoinhibition is removed when substrates are cleaved extracellularly, exposing the transmembrane domain for cleavage by γ-secretase103.”

• cites [103] Bolduc DM, Montagna DR, Gu Y, Selkoe DJ, Wolfe MS. Nicastrin functions to sterically hinder γ-secretase–substrate interactions driven by substrate transmembrane domain. Proc Natl Acad Sci USA. 2016; 113(5). doi: 10.1073/pnas.1512952113 PMC4747693 26699478 sourcePartly supported

  The Discussion (page unavailable) says nicastrin sterically blocks substrates with large ectodomains from entering the γ-secretase active site, explaining why ectodomain shedding is needed before cleavage. The paper supports the substrate-access mechanism, but does not say that shedding removes autoinhibition of the enzyme complex itself; its nicastrin gate remains in place. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

ENU mutagenesis generated the Wicked High Cholesterol (WHC) mouse model, which developed hypercholesterolemia at levels found in LDLR knockout animals.

“To model these Class II mutations ENU mutagenesis generated a mouse model, the Wicked High Cholesterol (WHC) mouse89, that developed hypercholesterolemia at levels found in LDLR knockout animals.”

• cites [89] Svenson KL, Ahituv N, Durgin RS, Savage H, Magnani PA, Foreman O, Paigen B, Peters LL. A new mouse mutant for the LDL receptor identified using ENU mutagenesis. Journal of Lipid Research. 2008; 49(11): 2452– 2462. doi: 10.1194/jlr.M800303-JLR200 18632552 PMC2563210 sourcePartly supported

  The Abstract identifies WHC as an LDL receptor mutation found through ENU mutagenesis. In “Comparison of WHC homozygotes to Ldlr KO strain” (page not provided), the paper reports similar cholesterol levels on chow, but significantly higher total cholesterol in knockout mice after an atherogenic diet. The unqualified claim that WHC reached knockout cholesterol levels omits that diet-dependent difference. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Enhanced PCSK9 binding forces LDLR to remain in an open conformation, preventing its recycling and promoting degradation of LDLR.

“This enhanced binding forces the LDLR to remain in an open conformation123,124, preventing its recycling and promoting degradation of LDLR.”

• cites [123] Lambert G, Sjouke B, Choque B, Kastelein JJP, Hovingh GK. The PCSK9 decade. J Lipid Res. 2012; 53(12): 2515– 2524. doi: 10.1194/jlr.R026658 22811413 PMC3494258 sourceSupported
• cites [124] Lo Surdo P, Bottomley MJ, Calzetta A, Settembre EC, Cirillo A, Pandit S, Ni YG, Hubbard B, Sitlani A, Carfí A. Mechanistic implications for LDL receptor degradation from the PCSK9/LDLR structure at neutral pH. EMBO Rep. 2011; 12(12): 1300– 1305. doi: 10.1038/embor.2011.205 22081141 PMC3245695 sourcePartly supported

  The Results and Discussion propose that PCSK9 might lock LDLR in an extended conformation and inhibit its transition to the closed form. Figure 4 describes how enhanced binding at endosomal pH could prevent changes associated with recycling and lead to LDLR degradation. The claim presents this proposed mechanism as an established effect by saying binding “forces” LDLR to remain open. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim. The paper’s conclusions may not depend on it.

BMP1 is a secreted protease.

“However, unlike MT1-MMP, BMP is a secreted protease109.”

• cites [109] Vadon-Le Goff S, Hulmes DJS, Moali C. BMP-1/tolloid-like proteinases synchronize matrix assembly with growth factor activation to promote morphogenesis and tissue remodeling. Matrix Biol. 2015; 44-46: 14– 23. doi: 10.1016/j.matbio.2015.02.006 25701650 sourceSupported

It may state two separate claims as one.

LDL particles are released from LDLR in the acidic environment of the sorting endosome, whereas the affinity of PCSK9 for LDLR increases 120-150-fold at low pH.

“Whereas LDL particles are released from the LDLR in the acidic environment of the sorting endosome, the affinity of PCSK9 for LDLR increases 120–150-fold at low pH121,122.”

• cites [121] Fisher TS, Lo Surdo P, Pandit S, Mattu M, Santoro JC, Wisniewski D, Cummings RT, Calzetta A, Cubbon RM, Fischer PA, Tarachandani A, De Francesco R, Wright SD, Sparrow CP, Carfi A, Sitlani A. Effects of pH and low density lipoprotein (LDL) on PCSK9-dependent LDL receptor regulation. J Biol Chem. 2007; 282(28): 20502– 20512. doi: 10.1074/jbc.M701634200 17493938 sourceSupported
• cites [122] Piper DE, Jackson S, Liu Q, Romanow WG, Shetterly S, Thibault ST, Shan B, Walker NPC. The crystal structure of PCSK9: a regulator of plasma LDL-cholesterol. Structure. 2007; 15(5): 545– 552. doi: 10.1016/j.str.2007.04.004 17502100 sourceNot checked — no full text of the source

It may state two separate claims as one.

A new proposed group of polymorphisms, Class VI mutations, includes variations of LDLR that do not properly thread into the plasma membrane and may also affect degradation rates of LDLR, specifically by PCSK9, IDOL, RNF130, and ASGR1, which can all act on LDLR at the cell surface.

“Lastly, there is a new proposed group of polymorphisms, Class VI mutations, that include variations of the LDLR that do not properly thread into the plasma membrane3, and may also affect degradation rates of the LDLR, specifically by PCSK9, IDOL, RNF130, and ASGR1, that can all act on LDLR at the cell surface (discussed further below).”

• cites [3] Banerjee P, Chan KC, Tarabocchia M, Benito-Vicente A, Alves AC, Uribe KB, Bourbon M, Skiba PJ, Pordy R, Gipe DA, Gaudet D, Martin C. Functional Analysis of LDLR (Low-Density Lipoprotein Receptor) Variants in Patient Lymphocytes to Assess the Effect of Evinacumab in Homozygous Familial Hypercholesterolemia Patients With a Spectrum of LDLR Activity. Arterioscler Thromb Vasc Biol. 2019; 39(11): 2248– 2260. doi: 10.1161/ATVBAHA.119.313051 31578082 PMC6818983 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

It may state two separate claims as one.

The cleaved N-terminal fragment of LDLR is detected in human urine, providing evidence that LDLR is cleaved by BMP1 in humans.

“The cleaved N-terminal fragment of LDLR is detected in human urine, providing evidence that LDLR is cleaved by BMP1 in humans110,111.”

• cites [110] Banerjee S, Andrew RJ, Duff CJ, Fisher K, Jackson CD, Lawrence CB, Maeda N, Greenspan DS, Kellett KAB, Hooper NM. Proteolysis of the low density lipoprotein receptor by bone morphogenetic protein-1 regulates cellular cholesterol uptake. Sci Rep. 2019; 9(1): 11416. doi: 10.1038/s41598-019-47814-0 31388055 PMC6684651 sourcePartly supported

  The Results section reports a cleaved LDLR fragment in human liver samples and shows that BMP1 cleaves human LDLR experimentally; the Discussion describes BMP1 as the likely protease in vivo. The paper detects the soluble N-terminal fragment in HepG2 cell culture medium, not human urine. The urine-specific evidence attributed to this source is therefore unsupported. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [111] Strøm TB, Bjune K, Leren TP. Bone morphogenetic protein 1 cleaves the linker region between ligand-binding repeats 4 and 5 of the LDL receptor and makes the LDL receptor non-functional. Hum Mol Genet. 2020; 29(8): 1229– 1238. doi: 10.1093/hmg/ddz238 31600776 sourceNot checked — no full text of the source

It may state two separate claims as one.

The WHC modification was found to trap LDLR in the ER, preventing glycosylation in the Golgi apparatus and resulting in protein degradation rather than trafficking to the cell surface.

“This modification was found to trap LDLR in the ER, preventing glycosylation in the Golgi apparatus, and resulting in protein degradation rather than trafficking to the cell surface89–91.”

• cites [89] Svenson KL, Ahituv N, Durgin RS, Savage H, Magnani PA, Foreman O, Paigen B, Peters LL. A new mouse mutant for the LDL receptor identified using ENU mutagenesis. Journal of Lipid Research. 2008; 49(11): 2452– 2462. doi: 10.1194/jlr.M800303-JLR200 18632552 PMC2563210 sourcePartly supported

  The Discussion (p. 2459) predicts that the WHC mutation prevents LDLR transport from the endoplasmic reticulum to the Golgi and cell surface; it does not report this as an observed finding. The passage does not establish that Golgi glycosylation is prevented or that the protein is degraded. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [90] Blasiole DA, Oler AT, Attie AD. Regulation of ApoB Secretion by the Low Density Lipoprotein Receptor Requires Exit from the Endoplasmic Reticulum and Interaction with ApoE or ApoB. Journal of Biological Chemistry. 2008; 283(17): 11374– 11381. doi: 10.1074/jbc.M710457200 18272520 PMC2431081 sourcePartly supported

  The Results (page unavailable) show that the C678Y LDLR mutant is retained in the ER and remains immature rather than acquiring the glycosylation that occurs in the Golgi. Our copy does not identify a WHC modification or show that this mutant LDLR is degraded instead of reaching the cell surface; the degradation discussed in these Results concerns apoB. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [91] Gillian-Daniel DL, Bates PW, Tebon A, Attie AD. Endoplasmic reticulum localization of the low density lipoprotein receptor mediates presecretory degradation of apolipoprotein B. Proc Natl Acad Sci USA. 2002; 99(7): 4337– 4342. doi: 10.1073/pnas.072557199 11904390 PMC123649 sourcePartly supported

  The Results and Discussion report that mutant LDLRs accumulated in the ER without reaching the cell surface. They do not identify a WHC modification or show that Golgi glycosylation was prevented; the protein shown to undergo increased degradation was apoB, not LDLR. Page numbers are unavailable in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Unlike other proprotein convertases, PCSK9 does not undergo a second cleavage to release the prodomain and is secreted as an enzymatically inactive protein.

“Unlike other proprotein convertases, PCSK9 does not undergo a second cleavage to release the prodomain and is secreted as an enzymatically inactive protein118.”

• cites [118] Seidah NG, Benjannet S, Wickham L, Marcinkiewicz J, Jasmin SB, Stifani S, Basak A, Prat A, Chretien M. The secretory proprotein convertase neural apoptosis-regulated convertase 1 (NARC-1): liver regeneration and neuronal differentiation. Proc Natl Acad Sci U S A. 2003; 100(3): 928– 933. doi: 10.1073/pnas.0335507100 12552133 PMC298703 sourcePartly supported

  The Discussion (page not available in our copy) says the cleaved prodomain remains associated with NARC-1 after secretion, and no second processing site was clearly identified. But it treats the absence of a secondary site as a possibility, not an established fact, and reports low but measurable activity in secreted NARC-1 rather than enzymatic inactivity. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Probably not a substantial claim. The paper’s conclusions may not depend on it.

PCSK9 is predominantly produced in hepatocytes, with some produced in intestinal and kidney cells.

“Proprotein convertase subtilsin-kexin type 9 (PCSK9) is predominantly produced in hepatocytes, with some in intestinal and kidney cells113,114.”

• cites [113] Rashid S, Curtis DE, Garuti R, Anderson NN, Bashmakov Y, Ho YK, Hammer RE, Moon YA, Horton JD. Decreased plasma cholesterol and hypersensitivity to statins in mice lacking Pcsk9. Proc Natl Acad Sci U S A. 2005; 102(15): 5374– 5379. doi: 10.1073/pnas.0501652102 15805190 PMC556275 sourcePartly supported

  The Results show PCSK9 protein in mouse liver, and the Discussion says PCSK9 is expressed at low levels in all tissues tested. The paper does not establish that hepatocytes are the predominant producers or specifically identify intestinal and kidney cells as producers. (LLM, conf=0.78)

  Experimental — accuracy not yet measured
• cites [114] Zaid A, Roubtsova A, Essalmani R, Marcinkiewicz J, Chamberland A, Hamelin J, Tremblay M, Jacques H, Jin W, Davignon J, Seidah NG, Prat A. Proprotein convertase subtilisin/kexin type 9 (PCSK9): hepatocyte-specific low-density lipoprotein receptor degradation and critical role in mouse liver regeneration. Hepatology. 2008; 48(2): 646– 654. doi: 10.1002/hep.22354 18666258 sourceSupported

It may state two separate claims as one.

BMP1 cleaves LDLR within its ligand binding domain, releasing a small N-terminal fragment and retaining a 120kDa membrane-bound C-terminal fragment.

“In contrast to MT1-MMP, BMP cleaves LDLR within its ligand binding domain, releasing a small N-terminal fragment, and retaining a 120kDa membrane-bound C-terminal fragment (Fig. 7C)110,111.”

• cites [110] Banerjee S, Andrew RJ, Duff CJ, Fisher K, Jackson CD, Lawrence CB, Maeda N, Greenspan DS, Kellett KAB, Hooper NM. Proteolysis of the low density lipoprotein receptor by bone morphogenetic protein-1 regulates cellular cholesterol uptake. Sci Rep. 2019; 9(1): 11416. doi: 10.1038/s41598-019-47814-0 31388055 PMC6684651 sourceSupported
• cites [111] Strøm TB, Bjune K, Leren TP. Bone morphogenetic protein 1 cleaves the linker region between ligand-binding repeats 4 and 5 of the LDL receptor and makes the LDL receptor non-functional. Hum Mol Genet. 2020; 29(8): 1229– 1238. doi: 10.1093/hmg/ddz238 31600776 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

MT1-MMP is a transmembrane protease that has well-known functions in extracellular matrix remodeling.

“MT1-MMP is a transmembrane protease that has well-known functions in extracellular matrix remodeling106.”

• cites [106] Itoh Y Membrane-type matrix metalloproteinases: Their functions and regulations. Matrix Biology. 2015; 44-46: 207– 223. doi: 10.1016/j.matbio.2015.03.004 25794647 sourceSupported

It may state two separate claims as one.

γ-secretase has been shown to cleave full-length LDLR, although extracellular cleavage may still occur prior to γ-secretase cleavage.

“However, γ-secretase has been shown to cleave the full-length LDLR, although extracellular cleavage may still occur prior to γ-secretase cleavage104.”

• cites [104] Kim K, Goldberg IJ, Graham MJ, Sundaram M, Bertaggia E, Lee SX, Qiang L, Haeusler RA, Metzger D, Chambon P, Yao Z, Ginsberg HN, Pajvani UB. γ-Secretase Inhibition Lowers Plasma Triglyceride-Rich Lipoproteins by Stabilizing the LDL Receptor. Cell Metabolism. 2018; 27(4): 816– 827.e4. doi: 10.1016/j.cmet.2018.02.010 29576536 PMC5884729 sourceSupported

Probably not a substantial claim.

MT1-MMP is highly expressed in multiple cancer cell types promoting metastasis and invasion.

“Interestingly, MT1-MMP is also highly expressed in multiple cancer cell types promoting metastasis and invasion106,108, thus inhibiting MT1-MMP holds both promise as a therapeutic target to reduce the risk of cancer metastasis and lower plasma LDL cholesterol.”

• cites [106] Itoh Y Membrane-type matrix metalloproteinases: Their functions and regulations. Matrix Biology. 2015; 44-46: 207– 223. doi: 10.1016/j.matbio.2015.03.004 25794647 sourcePartly supported

  The MT1-MMP section identifies MT1-MMP as a promoter of cancer-cell invasion and metastasis. The Gene and protein expression section describes its upregulation in particular cancer cell lines under specified conditions, but does not establish that it is generally highly expressed across multiple cancer cell types. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [108] Amar S, Smith L, Fields GB. Matrix metalloproteinase collagenolysis in health and disease. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 2017; 1864(11): 1940– 1951. doi: 10.1016/j.bbamcr.2017.04.015 28456643 PMC5605394 sourcePartly supported

  Section 5, “The role of collagen catabolism in disease” (page not provided), says MT1-MMP activity is critical for tumor-cell invasion through collagen and appears to play a significant role in metastasis. It does not establish that MT1-MMP is highly expressed in multiple cancer cell types; the expression passages found concern tuberculosis, not cancer. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

LDLR protein levels were increased with MT1-MMP liver-specific deletion, and MT1-MMP overexpression resulted in decreased LDLR expression, increased plasma cholesterol levels, and increased atherosclerotic lesions.

“LDLR protein levels were shown to be increased with MT1-MMP liver-specific deletion, and MT1-MMP overexpression resulted in decreased LDLR expression, increased plasma cholesterol levels, and increased atherosclerotic lesions107.”

• cites [107] Alabi A, Xia XD, Gu HM, Wang F, Deng SJ, Yang N, Adijiang A, Douglas DN, Kneteman NM, Xue Y, Chen L, Qin S, Wang G, Zhang DW. Membrane type 1 matrix metalloproteinase promotes LDL receptor shedding and accelerates the development of atherosclerosis. Nat Commun. 2021; 12(1): 1889. doi: 10.1038/s41467-021-22167-3 33767172 PMC7994674 sourceSupported

It may state two separate claims as one.

IDOL, also known as MYLIP, is an E3 ubiquitin ligase that mediates the ubiquitination and degradation of LDLR.

“Inducible Degrader Of the LDLR (IDOL), also known as MYLIP, is an E3 ubiquitin ligase that mediates the ubiquitination and degradation of the LDLR (Fig. 8B).”

• cites [134] Zelcer N, Hong C, Boyadjian R, Tontonoz P. LXR regulates cholesterol uptake through Idol-dependent ubiquitination of the LDL receptor. Science. 2009; 325(5936): 100– 104. doi: 10.1126/science.1168974 19520913 PMC2777523 sourceSupported

It may state two separate claims as one.

IDOL mediates LDLR protein degradation, as demonstrated through in vitro and in vivo studies.

“The ability of IDOL to mediate LDLR protein degradation was demonstrated through a series of well-executed in vitro and in vivo studies134.”

• cites [134] Zelcer N, Hong C, Boyadjian R, Tontonoz P. LXR regulates cholesterol uptake through Idol-dependent ubiquitination of the LDL receptor. Science. 2009; 325(5936): 100– 104. doi: 10.1126/science.1168974 19520913 PMC2777523 sourceSupported

It may state two separate claims as one.

Both the FERM and RING domains are required for IDOL activity, but they have functionally independent roles.

“These studies demonstrated that although both the FERM and RING domains are required for IDOL’s activity, they have functionally independent roles.”

• cites [137] Calkin AC, Goult BT, Zhang L, Fairall L, Hong C, Schwabe JWR, Tontonoz P. FERM-dependent E3 ligase recognition is a conserved mechanism for targeted degradation of lipoprotein receptors. Proc Natl Acad Sci U S A. 2011; 108(50): 20107– 20112. doi: 10.1073/pnas.1111589108 22109552 PMC3250164 sourceNot checked — no full text of the source
• cites [138] Sorrentino V, Scheer L, Santos A, Reits E, Bleijlevens B, Zelcer N. Distinct functional domains contribute to degradation of the low density lipoprotein receptor (LDLR) by the E3 ubiquitin ligase inducible Degrader of the LDLR (IDOL). J Biol Chem. 2011; 286(34): 30190– 30199. doi: 10.1074/jbc.M111.249557 21734303 PMC3191058 sourceSupported
• cites [139] Zhang L, Fairall L, Goult BT, Calkin AC, Hong C, Millard CJ, Tontonoz P, Schwabe JWR. The IDOL–UBE2D complex mediates sterol-dependent degradation of the LDL receptor. Genes Dev. 2011; 25(12): 1262– 1274. doi: 10.1101/gad.2056211 21685362 PMC3127428 sourcePartly supported

  The section ‘Disruption of the IDOL RING domain–UBE2D interaction inhibits LDLR degradation’ reports that a RING dimerization mutant could not promote LDLR degradation, supporting a requirement for the RING domain. The passages found do not establish that the FERM domain is required or that the two domains have functionally independent roles (searched: FERM and substrate recognition). (LLM, conf=0.82)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

ASGR1 functions to negatively regulate LDLR surface availability and LDL uptake.

“suggesting that ASGR1 functions to negatively regulate LDLR surface availability and LDL uptake146,147.”

• cites [146] Susan-Resiga D, Girard E, Essalmani R, Roubtsova A, Marcinkiewicz J, Derbali RM, Evagelidis A, Byun JH, Lebeau PF, Austin RC, Seidah NG. Asialoglycoprotein receptor 1 is a novel PCSK9-independent ligand of liver LDLR cleaved by furin. J Biol Chem. 2021; 297(4): 101177. doi: 10.1016/j.jbc.2021.101177 34508778 PMC8479480 sourceSupported
• cites [147] Xie B, Shi X, Li Y, Xia B, Zhou J, Du M, Xing X, Bai L, Liu E, Alvarez F, Jin L, Deng S, Mitchell GA, Pan D, Li M, Wu J. Deficiency of ASGR1 in pigs recapitulates reduced risk factor for cardiovascular disease in humans. Barsh GS, ed. PLoS Genet. 2021; 17(11): e1009891. doi: 10.1371/journal.pgen.1009891 34762653 PMC8584755 sourcePartly supported

  The Results report that ASGR1 deficiency increased hepatic LDLR protein and that ASGR1 knockdown increased LDL uptake in HepG2 cells, supporting a negative regulatory role. The paper does not establish the more specific claim about LDLR surface availability; its Discussion says whether ASGR1-mediated LDLR degradation occurs in vivo warrants further investigation. Page numbers are unavailable in our copy. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

PCSK9 has emerged as a key target for the treatment and prevention of FH, with successful preclinical studies in macaques and human clinical trials for Evolocumab.

“In fact, PCSK9 has emerged as a key target for the treatment and prevention of FH with successful preclinical studies in macaques132 and human clinical trials for Evolocumab133.”

• cites [132] Rothgangl T, Dennis MK, Lin PJC, Oka R, Witzigmann D, Villiger L, Qi W, Hruzova M, Kissling L, Lenggenhager D, Borrelli C, Egli S, Frey N, Bakker N, Walker JA 2nd, Kadina AP, Victorov DV, Pacesa M, Kreutzer S, Kontarakis Z, Moor A, Jinek M, Weissman D, Stoffel M, van Boxtel R, Holden K, Pardi N, Thöny B, Häberle J, Tam YK, Semple SC, Schwank G. In vivo adenine base editing of PCSK9 in macaques reduces LDL cholesterol levels. Nat Biotechnol. 2021; 39(8): 949– 957. doi: 10.1038/s41587-021-00933-4 34012094 PMC8352781 sourceSupported
• cites [133] Sabatine MS, Giugliano RP, Keech AC, Honarpour N, Wiviott SD, Murphy SA, Kuder JF, Wang H, Liu T, Wasserman SM, Sever PS, Pedersen TR. Evolocumab and Clinical Outcomes in Patients with Cardiovascular Disease. N Engl J Med. 2017; 376(18): 1713– 1722. doi: 10.1056/NEJMoa1615664 28304224 sourceSupported

It may state two separate claims as one.

IDOL is able to ubiquitinate and promote degradation of VLDLR and ApoER2.

“it was later revealed by sequence homology and LXR activation experiments that IDOL is also able to ubiquitinate and promote degradation of the related lipoprotein receptor family members, Very Low-density Lipoprotein Receptor (VLDL) and ApoE receptor 2 (ApoER2)136.”

• cites [136] Hong C, Duit S, Jalonen P, Out R, Scheer L, Sorrentino V, Boyadjian R, Rodenburg KW, Foley E, Korhonen L, Lindholm D, Nimpf J, Van Berkel TJC, Tontonoz P, Zelcer N. The E3 Ubiquitin Ligase IDOL Induces the Degradation of the Low Density Lipoprotein Receptor Family Members VLDLR and ApoER2. Journal of Biological Chemistry. 2010; 285(26): 19720– 19726. doi: 10.1074/jbc.M110.123729 20427281 PMC2888382 sourceSupported

It may state two separate claims as one.

Loss of function mutations in ASGR1 are associated with decreased non-HDL cholesterol levels and decreased risk of CAD.

“Indeed, loss of function mutations in ASGR1 are associated with decreased non-HDL cholesterol levels and decreased risk of CAD148.”

• cites [148] Nioi P, Sigurdsson A, Thorleifsson G, Helgason H, Agustsdottir AB, Norddahl GL, Helgadottir A, Magnusdottir A, Jonasdottir A, Gretarsdottir S, Jonsdottir I, Steinthorsdottir V, Rafnar T, Swinkels DW, Galesloot TE, Grarup N, Jørgensen T, Vestergaard H, Hansen T, Lauritzen T, Linneberg A, Friedrich N, Krarup NT, Fenger M, Abildgaard U, Hansen PR, Galløe AM, Braund PS, Nelson CP, Hall AS, Williams MJA, van Rij AM, Jones GT, Patel RS, Levey AI, Hayek S, Shah SH, Reilly M, Eyjolfsson GI, Sigurdardottir O, Olafsson I, Kiemeney LA, Quyyumi AA, Rader DJ, Kraus WE, Samani NJ, Pedersen O, Thorgeirsson G sourceSupported

It may state two separate claims as one.

Knockdown of ASGR1 increased total LDLR levels and LDL particle uptake.

“Knockdown of ASGR1 increased total LDLR levels and LDL particle uptake, suggesting that ASGR1 functions to negatively regulate LDLR surface availability and LDL uptake146,147.”

• cites [146] Susan-Resiga D, Girard E, Essalmani R, Roubtsova A, Marcinkiewicz J, Derbali RM, Evagelidis A, Byun JH, Lebeau PF, Austin RC, Seidah NG. Asialoglycoprotein receptor 1 is a novel PCSK9-independent ligand of liver LDLR cleaved by furin. J Biol Chem. 2021; 297(4): 101177. doi: 10.1016/j.jbc.2021.101177 34508778 PMC8479480 sourceSupported
• cites [147] Xie B, Shi X, Li Y, Xia B, Zhou J, Du M, Xing X, Bai L, Liu E, Alvarez F, Jin L, Deng S, Mitchell GA, Pan D, Li M, Wu J. Deficiency of ASGR1 in pigs recapitulates reduced risk factor for cardiovascular disease in humans. Barsh GS, ed. PLoS Genet. 2021; 17(11): e1009891. doi: 10.1371/journal.pgen.1009891 34762653 PMC8584755 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

GOLIATH ubiquitination promotes degradation of LDLR and decreases total LDLR levels.

“Although GOLIATH ubiquitination promotes degradation of LDLR and decreases total LDLR levels, the more significant effect of GOLIATH E3 ubiquitin ligase activity, is the subcellular redistribution of the LDLR143.”

• cites [143] Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, De Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circulation Research. 2023; 132(7): 849– 863. doi: 10.1161/CIRCRESAHA.122.321938 36876496 PMC10065965 sourceSupported

It may state two separate claims as one.

The C terminal domain of PCSK9 is not required for PCSK9 to bind and be internalized by LDLR, but appears to be required for PCSK9 to disrupt recycling of LDLR back to the cell surface.

“The C terminal domain of PCSK9 is also not required for PCSK9 to bind and be internalized by LDLR, it appears to be required for PCSK9 to disrupt recycling of LDLR back to the cell surface126,128.”

• cites [126] Tveten K, Holla OL, Cameron J, Strom TB, Berge KE, Laerdahl JK, Leren TP. Interaction between the ligand-binding domain of the LDL receptor and the C-terminal domain of PCSK9 is required for PCSK9 to remain bound to the LDL receptor during endosomal acidification. Human Molecular Genetics. 2012; 21(6): 1402– 1409. doi: 10.1093/hmg/ddr578 22156580 sourceNot checked — no full text of the source
• cites [128] Holla ØL, Cameron J, Tveten K, Strøm TB, Berge KE, Laerdahl JK, Leren TP. Role of the C-terminal domain of PCSK9 in degradation of the LDL receptors. J Lipid Res. 2011; 52(10): 1787– 1794. doi: 10.1194/jlr.M018093 21771976 PMC3173001 sourcePartly supported

  The introductory passage labeled Abstract says that PCSK9 lacking the C-terminal domain can bind LDLR but has little or no ability to mediate its degradation. The discussion in “Effect of replacing the C-terminal domain with an unrelated protein” proposes that a C-terminal structure interferes with LDLR sorting into recycling tubules, while leaving the exact mechanism unresolved. Our copy says that PCSK9 is internalized with LDLR, but does not establish that PCSK9 lacking the C-terminal domain is internalized with it. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

GOLIATH primarily functions to redistribute LDLR away from the cell surface, thereby reducing the ability of the receptor to bind and internalize LDL.

“GOLIATH primarily functions to redistribute LDLR away from the cell surface, thereby reducing the ability of the receptor to bind and internalize LDL.”

• cites [143] Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, De Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circulation Research. 2023; 132(7): 849– 863. doi: 10.1161/CIRCRESAHA.122.321938 36876496 PMC10065965 sourceSupported

It may state two separate claims as one.

IDOL possesses the ability to ubiquitinate itself and therefore undergoes autodegradation.

“As an E3 ubiquitin ligase, IDOL also possesses the ability to ubiquitinate itself and therefore undergoes autodegradation.”

• cites [134] Zelcer N, Hong C, Boyadjian R, Tontonoz P. LXR regulates cholesterol uptake through Idol-dependent ubiquitination of the LDL receptor. Science. 2009; 325(5936): 100– 104. doi: 10.1126/science.1168974 19520913 PMC2777523 sourcePartly supported

  The passage discussing Idol protein levels (section labeled Abstract; page unavailable) reports that mutating the RING domain greatly increased Idol levels, raising the possibility that Idol catalyzes its own degradation. It does not establish that Idol ubiquitinates itself, and it presents autodegradation as a possibility rather than a demonstrated ability. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

It may state two separate claims as one.

Released LDL is confined to the vesicular part of the sorting endosome that matures into the late endosome, while LDLR enters tubules of the sorting endosome for recycling back to the cell membrane, with each cycle taking approximately 10-15 minutes.

“The released LDL is confined to the vesicular part of the sorting endosome that eventually matures into the late endosome, while the LDLR enters the tubules of the sorting endosome for recycling back to the cell membrane, with each cycle taking approximately 10-15 minutes16.”

• cites [16] Brown MS, Anderson RG, Goldstein JL. Recycling receptors: the round-trip itinerary of migrant membrane proteins. Cell. 1983; 32(3): 663– 667. doi: 10.1016/0092-8674(83)90052-1 6299572 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The LDLR variant database identified 37 variants occurring in the promoter region.

“The LDLR variant database (generated by Leigh et. al.), identified 37 variants occurring in the promotor region33.”

• cites [33] Leigh S, Futema M, Whittall R, Taylor-Beadling A, Williams M, Den Dunnen JT, Humphries SE. The UCL low-density lipoprotein receptor gene variant database: pathogenicity update. J Med Genet. 2017; 54(4): 217– 223. doi: 10.1136/jmedgenet-2016-104054 27821657 PMC5502305 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

Recent studies have identified mRNA splicing factors that regulate LDLR expression and may contribute to LDLR mRNA half-life.

“Recent studies have identified mRNA splicing factors that regulate LDLR expression40 that may contribute to LDLR mRNA half-life.”

• cites [40] Zanoni P, Panteloglou G, Othman A, Haas JT, Meier R, Rimbert A, Futema M, Abou Khalil Y, Norrelykke SF, Rzepiela AJ, Stoma S, Stebler M, van Dijk F, Wijers M, Wolters JC, Dalila N, Huijkman NCA, Smit M, Gallo A, Carreau V, Philippi A, Rabès JP, Boileau C, Visentin M, Vonghia L, Weyler J, Francque S, Verrijken A, Verhaegen A, Van Gaal L, van der Graaf A, van Rosmalen BV, Robert J, Velagapudi S, Yalcinkaya M, Keel M, Radosavljevic S, Geier A, Tybjaerg-Hansen A, Varret M, Rohrer L, Humphries SE, Staels B, van de Sluis B, Kuivenhoven JA, von Eckardstein A. Posttranscriptional Regulation of the Hum sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

Muller et al. screened exons 5-10 of LDLR from 70 hypercholesteremic patients and identified several variations, including one amino acid exchange in the bHLH-Zip domain in three patients.

“A second study by Muller et. al. screened exons 5-10 of LDLR from 70 hypercholesteremic patients34 and identified several variations, with one being an amino acid exchange in the bHLH-Zip domain identified in three of the pateints34.”

• cites [34] Muller PY. Identification of mutations in the gene encoding sterol regulatory element binding protein (SREBP)-2 in hypercholesterolaemic subjects. Journal of Medical Genetics. 2002; 39(4): 271– 275. doi: 10.1136/jmg.39.4.271 11950857 PMC1735089Not checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The human LDLR gene is located on chromosome 19, spans approximately 45 kb, and consists of 18 exons and 17 introns.

“The human LDLR gene, located on chromosome 19, spans approximately 45kb consisting of 18 exons and 17 introns18.”

• cites [18] Lindgren V, Luskey KL, Russell DW, Francke U. Human genes involved in cholesterol metabolism: chromosomal mapping of the loci for the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl-coenzyme A reductase with cDNA probes. Proc Natl Acad Sci USA. 1985; 82(24): 8567– 8571. doi: 10.1073/pnas.82.24.8567 3866240 PMC390958 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

LDLR is a type I membrane protein with an extracellular/luminal N-terminus, a single transmembrane helix, and a cytosolic C-terminus.

“LDLR is a type I membrane protein, meaning that it possesses an extracellular/luminal N-terminus, followed by a single transmembrane helix and a cytosolic C-terminus, such that this integral membrane protein spans the entirety of the cell membrane11–13.”

• cites [11] Russell DW, Schneider WJ, Yamamoto T, Luskey KL, Brown MS, Goldstein JL. Domain map of the LDL receptor: Sequence homology with the epidermal growth factor precursor. Cell. 1984; 37(2): 577– 585. doi: 10.1016/0092-8674(84)90388-X 6327078 sourceNot checked — no full text of the source
• cites [12] Yamamoto T, Davis CG, Brown MS, Schneider WJ, Casey ML, Goldstein JL, Russell DW. The human LDL receptor: A cysteine-rich protein with multiple Alu sequences in its mRNA. Cell. 1984; 39(1): 27– 38. doi: 10.1016/0092-8674(84)90188-0 6091915 sourceNot checked — no full text of the source
• cites [13] Südhof TC, Goldstein JL, Brown MS, Russell DW. The LDL Receptor Gene: A Mosaic of Exons Shared with Different Proteins. Science. 1985; 228(4701): 815– 822. doi: 10.1126/science.2988123 2988123 PMC4450672 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The SIRE domain can be bound by factors including ATF3 and cEBP to activate transcription.

“Similarly, the SIRE domain can be bound by factors including ATF3 and cEBP to activate transcription24,32.”

• cites [24] Liu J, Ahlborn TE, Briggs MR, Kraemer FB. Identification of a Novel Sterol-independent Regulatory Element in the Human Low Density Lipoprotein Receptor Promoter. Journal of Biological Chemistry. 2000; 275(7): 5214– 5221. doi: 10.1074/jbc.275.7.5214 10671569 sourceNot checked yet

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• cites [32] Zhou Y, Zhang F, Abidi P, Lin M, Thiel G, Liu J. Blockage of oncostatin M-induced LDL receptor gene transcription by a dominant-negative mutant of C/EBPbeta. Biochem J. 2006; 397(1): 101– 108. doi: 10.1042/BJ20060044 16563127 PMC1479763 sourceNot checked yet

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Of LDLR mutations, all result in familial hypercholesterolemia, and most result in loss of LDLR function, either through complete loss of protein or production of a modified nonfunctional protein.

“Of these mutations, all result in FH, and most result in loss of LDLR function, either through complete loss of protein or production of a modified protein which is nonfunctional.”

• cites [1] Galicia-Garcia U, Benito-Vicente A, Uribe KB, Jebari S, Larrea-Sebal A, Alonso-Estrada R, Aguilo-Arce J, Ostolaza H, Palacios L, Martin C. Mutation type classification and pathogenicity assignment of sixteen missense variants located in the EGF-precursor homology domain of the LDLR. Scientific reports. 2020; 10(1): 1727. doi: 10.1038/s41598-020-58734-9 32015373 PMC6997160 sourceNot checked yet

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Despite large clinical success, current lipid-lowering treatments do not always restore plasma cholesterol levels to within a normal physiological range and can increase the risk of developing other diseases such as type 2 diabetes.

“Despite their large clinical success, these treatments do not always restore plasma cholesterol levels to within a normal physiological range8 and can increase the risk of developing other diseases such as type 2 diabetes9.”

• cites [8] Pijlman AH, Huijgen R, Verhagen SN, Imholz BPM, Liem AH, Kastelein JJP, Abbink EJ, Stalenhoef AFH, Visseren FLJ. Evaluation of cholesterol lowering treatment of patients with familial hypercholesterolemia: a large cross-sectional study in The Netherlands. Atherosclerosis. 2010; 209(1): 189– 194. doi: 10.1016/j.atherosclerosis.2009.09.014 19818960 sourceNot checked — no full text of the source
• cites [9] Preiss D, Seshasai SRK, Welsh P, Murphy SA, Ho JE, Waters DD, DeMicco DA, Barter P, Cannon CP, Sabatine MS, Braunwald E, Kastelein JJP, de Lemos JA, Blazing MA, Pedersen TR, Tikkanen MJ, Sattar N, Ray KK. Risk of incident diabetes with intensive-dose compared with moderate-dose statin therapy: a meta-analysis. JAMA. 2011; 305(24): 2556– 2564. doi: 10.1001/jama.2011.860 21693744 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Approximately 45 minutes after synthesis, LDLR is inserted into the cell membrane.

“Approximately 45 minutes after synthesis, the LDLR is inserted into the cell membrane14”

• cites [14] Goldstein JL, Hobbs HH, Brown MS. Familial Hypercholesterolemia. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill Education; 2019. Accessed October 10, 2024. ommbid.mhmedical.com/content.aspx?aid=1181450244Not checked yet

It may state two separate claims as one.

Nuclear active SREBP-2 is polyubiquitinated and rapidly degraded by the proteasome with an estimated half-life of 3 hours.

“Nuclear active SREBP-2 is not long-lived and is polyubiquitinated and rapidly degraded by the proteasome with an estimated half-life of 3 hr28.”

• cites [28] Hirano Y, Yoshida M, Shimizu M, Sato R. Direct Demonstration of Rapid Degradation of Nuclear Sterol Regulatory Element-binding Proteins by the Ubiquitin-Proteasome Pathway. Journal of Biological Chemistry. 2001; 276(39): 36431– 36437. doi: 10.1074/jbc.M105200200 11477106 sourceNot checked — no full text of the source

It may state two separate claims as one.

The LDLR gene promoter contains three imperfect direct 16 bp repeats, two TATA-like sequences, and multiple transcription initiation sites, all required for gene expression and regulation.

“The promoter region contains three imperfect direct 16 bp repeats, two TATA-like sequences, and multiple transcription initiation sites, which are all required for gene expression and regulation19”

• cites [19] Südhof TC, Van Der Westhuyzen DR, Goldstein JL, Brown MS, Russell DW. Three direct repeats and a TATA-like sequence are required for regulated expression of the human low density lipoprotein receptor gene. Journal of Biological Chemistry. 1987; 262(22): 10773– 10779. doi: 10.1016/S0021-9258(18)61030-0 3611089 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The average life-span of LDLR is approximately 24 hours, and an individual LDLR molecule makes roughly 100 cycles before lysosomal degradation.

“With the average life-span of the LDLR being approximately 24 hr, an individual LDLR molecule makes roughly 100 of these cycles before it is degraded in the lysosome17.”

• cites [17] Brown MS, Herz J, Goldstein JL. LDL-receptor structure. Calcium cages, acid baths and recycling receptors. Nature. 1997; 388(6643): 629– 630. doi: 10.1038/41672 9262394 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Base-pairing interactions between a miRNA and its mRNA target allow targeting of the mRNA for degradation or repression of translation.

“Base-pairing interactions between the miRNA and mRNA target, allow for targeting of the mRNA for degradation or repression of translation42,46.”

• cites [42] Bushati N, Cohen SM. microRNA Functions. Annu Rev Cell Dev Biol. 2007; 23(1): 175– 205. doi: 10.1146/annurev.cellbio.23.090506.123406 17506695 sourceNot checked — no full text of the source
• cites [46] Hutvágner G, Zamore PD. A microRNA in a Multiple-Turnover RNAi Enzyme Complex. Science. 2002; 297(5589): 2056– 2060. doi: 10.1126/science.1073827 12154197 sourceNot checked — no full text of the source

It may state two separate claims as one.

Choi et al. demonstrated that miR-27a regulates LDLR and decreases the infectivity of hepatitis C virus.

“Choi et. al. demonstrated that miR-27a regulates LDLR and decreases the infectivity of hepatitis C virus56.”

• cites [56] Choi JE, Hur W, Kim JH, Li TZ, Lee EB, Lee SW, Kang W, Shin EC, Wakita T, Yoon SK. MicroRNA-27a Modulates HCV Infection in Differentiated Hepatocyte-Like Cells from Adipose Tissue-Derived Mesenchymal Stem Cells. Lee SB, ed. PLoS ONE. 2014; 9(5): e91958. doi: 10.1371/journal.pone.0091958 24824429 PMC4019502 sourceNot checked yet

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Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

SREBP-2 is synthesized as an inactive form and anchored to the ER membrane by SCAP, in a 4:4 oligomer ratio in yeast.

“SREBP-2 is synthesized as an inactive form and anchored to the ER membrane by SREBP-cleavage activating protein (SCAP), in a 4:4 oligomer ratio in yeast68.”

• cites [68] Gong X, Qian H, Shao W, Li J, Wu J, Liu JJ, Li W, Wang HW, Espenshade P, Yan N. Complex structure of the fission yeast SREBP-SCAP binding domains reveals an oligomeric organization. Cell Res. 2016; 26(11): 1197– 1211. doi: 10.1038/cr.2016.123 27811944 PMC5099872 sourceNot checked yet

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Overexpression of miR-185 in HepG2 cells resulted in decreased expression of LDLR mRNA and protein and decreased LDL uptake.

“Overexpression of miR-185 in HepG2 cells resulted in decreased expression of LDLR mRNA and protein and decreased LDL uptake54.”

• cites [54] Jiang H, Zhang J, Du Y, Jia X, Yang F, Si S, Wang L, Hong B. microRNA-185 modulates low density lipoprotein receptor expression as a key posttranscriptional regulator. Atherosclerosis. 2015; 243(2): 523– 532. doi: 10.1016/j.atherosclerosis.2015.10.026 26523989 sourceNot checked — no full text of the source

It may state two separate claims as one.

Berberine, a natural compound used as a cholesterol lowering drug, was found to have similar results as statins but functions through an alternative mechanism involving the 3'UTR and independent of changes in LDLR transcriptional activity.

“Berberine, a natural compound used as a cholesterol lowering drug, was found to have similar results as statins, but function through an alternative mechanism involving the 3’UTR and independent of changes in LDLR transcriptional activity62.”

• cites [62] Kong W, Wei J, Abidi P, Lin M, Inaba S, Li C, Wang Y, Wang Z, Si S, Pan H, Wang S, Wu J, Wang Y, Li Z, Liu J, Jiang JD. Berberine is a novel cholesterol-lowering drug working through a unique mechanism distinct from statins. Nat Med. 2004; 10(12): 1344– 1351. doi: 10.1038/nm1135 15531889 sourceNot checked — no full text of the source

It may state two separate claims as one.

In vivo overexpression of a lentivirus containing miR-185 antisense oligonucleotides led to increased hepatic LDLR expression and decreased plasma cholesterol and atherosclerosis burden in Apoe-/- mice.

“Finally, in vivo overexpression of a lentivirus containing miR-185 antisense oligonucleotides led to increased levels of hepatic LDLR expression and decreased plasma cholesterol and atherosclerosis burden in Apoe–/– mice54.”

• cites [54] Jiang H, Zhang J, Du Y, Jia X, Yang F, Si S, Wang L, Hong B. microRNA-185 modulates low density lipoprotein receptor expression as a key posttranscriptional regulator. Atherosclerosis. 2015; 243(2): 523– 532. doi: 10.1016/j.atherosclerosis.2015.10.026 26523989 sourceNot checked — no full text of the source

It may state two separate claims as one.

miR-148a, miR-130b, miR-301b, and miR-128-1 directly interact with the 3'UTR of LDLR to decrease expression, and overexpression of these miRNAs decreased LDL-C uptake in HepG2 cells.

“MiR-148a, miR-130b, miR-301b, and miR-128-1 were shown to directly interact with the 3’UTR of LDLR to decrease expression and functionally, overexpression of these miRNAs decreased LDL-C uptake in HepG2 cells51.”

• cites [51] Wagschal A, Najafi-Shoushtari SH, Wang L, Goedeke L, Sinha S, deLemos AS, Black JC, Ramírez CM, Li Y, Tewhey R, Hatoum I, Shah N, Lu Y, Kristo F, Psychogios N, Vrbanac V, Lu YC, Hla T, De Cabo R, Tsang JS, Schadt E, Sabeti PC, Kathiresan S, Cohen DE, Whetstine J, Chung RT, Fernández-Hernando C, Kaplan LM, Bernards A, Gerszten RE, Näär AM. Genome-wide identification of microRNAs regulating cholesterol and triglyceride homeostasis. Nat Med. 2015; 21(11): 1290– 1297. doi: 10.1038/nm.3980 26501192 PMC4993048 sourceNot checked yet

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Like other LDLR-related family members, following the ligand binding domain, the remaining extracellular portion of LDLR includes repeated EGF-like domains and YWTD repeats.

“Like other LDLR-related family members79, following the ligand binding domain, the remaining extracellular portion of the protein includes repeated epidermal-growth factor (EGF) like domains, and a series of tyrosine-tryptophan-threonine-asparagine repeats (YWTD repeats).”

• cites [79] Wang S, Mao Y, Narimatsu Y, Ye Z, Tian W, Goth CK, Lira-Navarrete E, Pedersen NB, Benito-Vicente A, Martin C, Uribe KB, Hurtado-Guerrero R, Christoffersen C, Seidah NG, Nielsen R, Christensen EI, Hansen L, Bennett EP, Vakhrushev SY, Schjoldager KT, Clausen H. Site-specific O-glycosylation of members of the low-density lipoprotein receptor superfamily enhances ligand interactions. J Biol Chem. 2018; 293(19): 7408– 7422. doi: 10.1074/jbc.M117.817981 29559555 PMC5949982 sourceNot checked yet

It may state two separate claims as one.

There are two predicted miR-148a binding sites (ACGUGA) in the human 3'UTR of LDLR at positions 872-878 and 1971-1978, with the first being highly conserved across mammalian species.

“There are two predicted miR-148a binding sites (ACGUGA) in the human 3’UTR of LDLR at positions 872-878 and 1971-1978, the first being highly conserved across mammalian species52.”

• cites [52] Goedeke L, Rotllan N, Canfrán-Duque A, Aranda JF, Ramírez CM, Araldi E, Lin CS, Anderson NN, Wagschal A, De Cabo R, Horton JD, Lasunción MA, Näär AM, Suárez Y, Fernández-Hernando C. MicroRNA-148a regulates LDL receptor and ABCA1 expression to control circulating lipoprotein levels. Nat Med. 2015; 21(11): 1280– 1289. doi: 10.1038/nm.3949 26437365 PMC4711995 sourceNot checked yet

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It may state two separate claims as one.

Luciferase reporter assays involving mutations of the miR-185 binding sites in the LDLR 3'UTR stabilized luciferase expression, suggesting miR-185 regulation of LDLR at these binding sites.

“Additionally, luciferase reporter assays involving mutations of the miR-185 binding sites in the LDLR 3’UTR stabilized the luciferase expression, suggesting miR-185 regulation of LDLR at these binding sites54.”

• cites [54] Jiang H, Zhang J, Du Y, Jia X, Yang F, Si S, Wang L, Hong B. microRNA-185 modulates low density lipoprotein receptor expression as a key posttranscriptional regulator. Atherosclerosis. 2015; 243(2): 523– 532. doi: 10.1016/j.atherosclerosis.2015.10.026 26523989 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

A summary of multiple RNA interactome capture studies identified 1,914 and 1,393 RBPs in mice and humans, respectively.

“A summary of multiple RNA interactome capture studies identified 1,914 and 1,393 RBPs in mice and humans, respectively58, making them much more abundant than transcription factors.”

• cites [58] Hentze MW, Castello A, Schwarzl T, Preiss T. A brave new world of RNA-binding proteins. Nat Rev Mol Cell Biol. 2018; 19(5): 327– 341. doi: 10.1038/nrm.2017.130 29339797 sourceNot checked yet

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In detailing the LDLR ligand binding domain bound to a β-belt in ApoB, the impact of specific Class II mutations associated with familial hypercholesterolemia can now be modeled and are highlighted in structural diagrams.

“In detailing the LDLR ligand binding domain bound to a β-belt in ApoB, the impact of specific Class II mutations associated with FH can now be modeled and are in fact highlighted in structural diagrams reported in one of the studies78.”

• cites [78] Reimund M, Dearborn AD, Graziano G, Lei H, Ciancone AM, Kumar A, Holewinski R, Neufeld EB, O’Reilly FJ, Remaley AT, Marcotrigiano J. Structure of apolipoprotein B100 bound to the low-density lipoprotein receptor. Nature. Published online December 11, 2024. doi: 10.1038/s41586-024-08223-0 39663455 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it.

RNA binding proteins are post-transcriptional regulators of protein expression that bind RNA recognition motifs within the 5'UTR, coding region, or 3'UTR of target genes to facilitate alternative splicing, RNA export, translation, and stabilization or degradation of RNA transcripts.

“RNA binding proteins (RBPs) are post-transcriptional regulators of protein expression that bind RNA recognition motifs within the 5’UTR, coding region (intron or exon), or 3’UTR of target genes to facilitate a variety of functions including alternative splicing, RNA export from the nucleus, translation, and stabilization or degradation of RNA transcripts58,59.”

• cites [58] Hentze MW, Castello A, Schwarzl T, Preiss T. A brave new world of RNA-binding proteins. Nat Rev Mol Cell Biol. 2018; 19(5): 327– 341. doi: 10.1038/nrm.2017.130 29339797 sourceNot checked yet

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• cites [59] Kelaini S, Chan C, Cornelius VA, Margariti A. RNA-Binding Proteins Hold Key Roles in Function, Dysfunction, and Disease. Biology. 2021; 10(5): 366. doi: 10.3390/biology10050366 33923168 PMC8146904 sourceNot checked yet

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Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

miRNAs are small non-coding RNAs approximately 22 nucleotides in length that typically interact with the 3'UTR of target mRNAs, although interaction with the 5'UTR and coding regions has also been reported.

“miRNAs are small non-coding RNAs, approximately 22 nucleotides in length, that typically interact with the 3’UTR of their target mRNAs, although interaction with the 5’UTR and coding regions of targets has also been reported45.”

• cites [45] Ha M, Kim VN. Regulation of microRNA biogenesis. Nat Rev Mol Cell Biol. 2014; 15(8): 509– 524. doi: 10.1038/nrm3838 25027649 sourceNot checked — no full text of the source

It may state two separate claims as one.

The EGF-like and YWTD repeats are thought to allow proper positioning of the ligand binding domain and have been shown to promote release of cargo in the endosome in a pH-dependent manner.

“These repeats are thought to both allow proper positioning of the ligand binding domain and have been shown to promote the release of cargo in the endosome in a pH-dependent manner80.”

• cites [80] Yamamoto T, Lamoureux J, Ryan RO. Characterization of low density lipoprotein receptor ligand interactions by fluorescence resonance energy transfer. Journal of Lipid Research. 2006; 47(5): 1091– 1096. doi: 10.1194/jlr.D600001-JLR200 16467279 sourceNot checked — no full text of the source

It may state two separate claims as one.

The LDLR peptide has an N-terminal ligand binding domain with high affinity for Apolipoprotein E and Apolipoprotein B, the main structural components of VLDL/LDL.

“The LDLR peptide has an N-terminal ligand binding domain which has high affinity for Apolipoprotein E74,75, as well as Apolipoprotein B (ApoB)76, the main structural components of VLDL/LDL.”

• cites [74] Goldstein JL, Brown MS. Binding and degradation of low density lipoproteins by cultured human fibroblasts. Comparison of cells from a normal subject and from a patient with homozygous familial hypercholesterolemia. J Biol Chem. 1974; 249(16): 5153– 5162. 4368448 sourceNot checked — no full text of the source
• cites [75] Wang JQ, Li LL, Hu A, Deng G, Wei J, Li YF, Liu YB, Lu XY, Qiu ZP, Shi XJ, Zhao X, Luo J, Song BL. Inhibition of ASGR1 decreases lipid levels by promoting cholesterol excretion. Nature. 2022; 608(7922): 413– 420. doi: 10.1038/s41586-022-05006-3 35922515 sourceNot checked — no full text of the source
• cites [76] Schneider WJ, Beisiegel U, Goldstein JL, Brown MS. Purification of the low density lipoprotein receptor, an acidic glycoprotein of 164,000 molecular weight. Journal of Biological Chemistry. 1982; 257(5): 2664– 2673. doi: 10.1016/S0021-9258(18)34975-5 6277909 sourceNot checked — no full text of the source

It may state two separate claims as one.

SCAP and SREBP-2 are incorporated into COPII vesicles that bud off the ER and can be transported to the Golgi apparatus.

“SCAP and SREBP-2 are then incorporated into these COPII vesicles that bud off of the ER and can be transported to the Golgi apparaturs70.”

• cites [70] Espenshade PJ, Li WP, Yabe D. Sterols block binding of COPII proteins to SCAP, thereby controlling SCAP sorting in ER. Proc Natl Acad Sci USA. 2002; 99(18): 11694– 11699. doi: 10.1073/pnas.182412799 12193656 PMC129331 sourceNot checked — no full text of the source

It may state two separate claims as one.

Alvarez et al. demonstrated that miR-27a interacts directly with the predicted LDLR binding site, and mutations in this site prevented interaction and regulation by miR-27a in HepG2 cells.

“Alvarez et. al, demonstrated that miR-27a interacts directly with the predicted LDLR binding site, and that mutations in this site prevented interaction and regulation by the miR-27a in HepG2 cells55.”

• cites [55] Alvarez ML, Khosroheidari M, Eddy E, Done SC. MicroRNA-27a decreases the level and efficiency of the LDL receptor and contributes to the dysregulation of cholesterol homeostasis. Atherosclerosis. 2015; 242(2): 595– 604. doi: 10.1016/j.atherosclerosis.2015.08.023 26318398 PMC4575910 sourceNot checked yet

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Carriers of the 2.5 kb 3'UTR deletion variant had LDL levels in the first percentile and did not contain other known mutations in cholesterol handling genes known to cause familial hypercholesterolemia.

“Carriers of this variant had LDL levels in the first percentile and did not contain other known mutations in cholesterol handling genes known to cause FH67.”

• cites [67] Bjornsson E, Gunnarsdottir K, Halldorsson GH, Sigurdsson A, Arnadottir GA, Jonsson H, Olafsdottir EF, Niehus S, Kehr B, Sveinbjörnsson G, Gudmundsdottir S, Helgadottir A, Andersen K, Thorleifsson G, Eyjolfsson GI, Olafsson I, Sigurdardottir O, Saemundsdottir J, Jonsdottir I, Magnusson OTh, Masson G, Stefansson H, Gudbjartsson DF, Thorgeirsson G, Holm H, Halldorsson BV, Melsted P, Norddahl GL, Sulem P, Thorsteinsdottir U, Stefansson K. Lifelong Reduction in LDL (Low-Density Lipoprotein) Cholesterol due to a Gain-of-Function Mutation in LDLR. Circ: Genomic and Precision Medicine. 2021; 14(1): e0 sourceNot checked — no full text of the source

It may state two separate claims as one.

A coding variant in CCDC93 increases CCDC93 protein stability, which is associated with lower LDL-C levels and reduced CVD mortality.

“Importantly, a coding variant in CCDC93 increases CCDC93 protein stability, which is associated with lower LDL-C levels and reduced CVD mortality100”

• cites [100] Rimbert A, Dalila N, Wolters JC, Huijkman N, Smit M, Kloosterhuis N, Riemsma M, van der Veen Y, Singla A, van Dijk F, Biobank-Based Integrative Omics Studies Consortium, Frikke-Schmidt R, Burstein E, Tybjærg-Hansen A, van de Sluis B, Kuivenhoven JA. A common variant in CCDC93 protects against myocardial infarction and cardiovascular mortality by regulating endosomal trafficking of low-density lipoprotein receptor. Eur Heart J. 2020; 41(9): 1040– 1053. doi: 10.1093/eurheartj/ehz727 31630160 sourceNot checked yet

It may state two separate claims as one.

PCSK9 is a dual function regulator of LDLR, acting intracellularly as a chaperone that guides LDLR towards degradation and as a secreted factor that promotes LDLR internalization.

“PCSK9 is a dual function regulator of LDLR, acting both intracellularly as a chaperone that guides LDLR towards degradation, as well as a secreted factor that promotes LDLR internalization (Fig. 8A).”

It may state two separate claims as one.

Once dissociated, LDLR is either degraded or recycled back to the cell surface where it can bind new cargo and repeat the process.

“Once dissociated, LDLR is either degraded or recycled back to the cell surface where it can bind new cargo and repeat this process95,96.”

• cites [95] Davis CG, Goldstein JL, Südhof TC, Anderson RG, Russell DW, Brown MS. Acid-dependent ligand dissociation and recycling of LDL receptor mediated by growth factor homology region. Nature. 1987; 326(6115): 760– 765. doi: 10.1038/326760a0 3494949 sourceNot checked — no full text of the source
• cites [96] Rodrigues VZ, Foro S, Gowda BT. N -(2,6-Dichlorophenyl)-4-methylbenzamide. Acta Crystallogr E Struct Rep Online. 2011; 67(8): o2123– o2123. doi: 10.1107/S1600536811028935 PMC3213564 22091141 sourceNot checked yet

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Glycosylation sites on LDLR not only impact LDLR stability and function but may also affect degradation rates of LDLR, specifically by ASGR1, an E3 ligase which recognizes a glycosylated region of LDLR.

“These glycosylation sites not only impact LDLR stability and function, but may also affect degradation rates of the LDLR, specifically by ASGR1 (discussed in more detail below), an E3 ligase which recognizes a glycosylated region of LDLR75.”

• cites [75] Wang JQ, Li LL, Hu A, Deng G, Wei J, Li YF, Liu YB, Lu XY, Qiu ZP, Shi XJ, Zhao X, Luo J, Song BL. Inhibition of ASGR1 decreases lipid levels by promoting cholesterol excretion. Nature. 2022; 608(7922): 413– 420. doi: 10.1038/s41586-022-05006-3 35922515 sourceNot checked — no full text of the source

It may state two separate claims as one.

The ligand binding region of LDLR contains seven cysteine-rich repeats that fold to present a cluster of negatively charged amino acids for ligand binding, allowing the positively charged region of apolipoproteins to bind LDLR.

“The ligand binding region of LDLR contains seven cysteine-rich repeats which fold such that a cluster of negatively charged amino acids are presented for ligand binding85 allowing for the positively-charged region of Apolipoproteins to bind LDLR.”

• cites [85] Goldstein JL, Brown MS, Anderson RGW, Russell DW, Schneider WJ. Receptor-Mediated Endocytosis: Concepts Emerging from the LDL Receptor System. Annu Rev Cell Biol. 1985; 1(1): 1– 39. doi: 10.1146/annurev.cb.01.110185.000245 2881559 sourceNot checked — no full text of the source

It may state two separate claims as one.

An LDLR lacking the ligand binding domain is able to internalize PCSK9 but is not degraded and instead recycles back to the plasma membrane.

“A series of deletion studies demonstrate that an LDLR lacking the ligand binding domain is able to internalize PCSK9 but is not degraded and instead recycles back to the plasma membrane126,127.”

• cites [126] Tveten K, Holla OL, Cameron J, Strom TB, Berge KE, Laerdahl JK, Leren TP. Interaction between the ligand-binding domain of the LDL receptor and the C-terminal domain of PCSK9 is required for PCSK9 to remain bound to the LDL receptor during endosomal acidification. Human Molecular Genetics. 2012; 21(6): 1402– 1409. doi: 10.1093/hmg/ddr578 22156580 sourceNot checked — no full text of the source
• cites [127] Zhang DW, Garuti R, Tang WJ, Cohen JC, Hobbs HH. Structural requirements for PCSK9-mediated degradation of the low-density lipoprotein receptor. Proc Natl Acad Sci U S A. 2008; 105(35): 13045– 13050. doi: 10.1073/pnas.0806312105 18753623 PMC2526098 sourceNot checked yet

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It may state two separate claims as one.

Internalized PCSK9 is released from LDLR lacking the ligand binding domain in sorting endosomes, suggesting that the ligand binding domain may be required for PCSK9 to remain bound to LDLR at the low pH of the sorting endosome.

“This recycling indicates that internalized PCSK9 is released from LDLR lacking the ligand binding domain in sorting endosomes, suggesting that the ligand binding domain may be required for PCSK9 to remain bound to LDLR at the low pH of the sorting endosome.”

It may state two separate claims as one.

The ARH-NPxY interaction allows binding of AP-2 protein, which recruits additional clathrin, leading to clathrin polymerization and invagination of the plasma membrane to initiate endocytosis.

“This interaction allows binding of the AP-2 protein81, which recruits additional clathrin leading to clathrin polymerization and invagination of the plasma membrane to initiate endocytosis.”

• cites [81] Maurer ME, Cooper JA. The adaptor protein Dab2 sorts LDL receptors into coated pits independently of AP-2 and ARH. Journal of Cell Science. 2006; 119(20): 4235– 4246. doi: 10.1242/jcs.03217 16984970 sourceNot checked — no full text of the source

It may state two separate claims as one.

Brown and Goldstein demonstrated that fibroblasts from healthy individuals can bind and internalize radiolabeled LDL particles, while fibroblasts from patients with familial hypercholesterolemia cannot.

“The concept that LDL was brought into the cell in a receptor-mediated manner (Fig. 6) was confirmed in the 1970s when Brown and Goldstein demonstrated that fibroblasts from healthy individuals can bind and internalize radiolabeled LDL particles, while fibroblasts from patients with familial hypercholesterolemia cannot74.”

• cites [74] Goldstein JL, Brown MS. Binding and degradation of low density lipoproteins by cultured human fibroblasts. Comparison of cells from a normal subject and from a patient with homozygous familial hypercholesterolemia. J Biol Chem. 1974; 249(16): 5153– 5162. 4368448 sourceNot checked — no full text of the source

It may state two separate claims as one.

Disruption of the LDLR ligand binding domain reduces the receptor's affinity for LDL, thereby reducing its ability to bind and internalize LDL.

“The disruption of the ligand binding domain reduces affinity of the receptor for LDL, thereby reducing the ability to bind and internalize LDL110.”

• cites [110] Banerjee S, Andrew RJ, Duff CJ, Fisher K, Jackson CD, Lawrence CB, Maeda N, Greenspan DS, Kellett KAB, Hooper NM. Proteolysis of the low density lipoprotein receptor by bone morphogenetic protein-1 regulates cellular cholesterol uptake. Sci Rep. 2019; 9(1): 11416. doi: 10.1038/s41598-019-47814-0 31388055 PMC6684651 sourceNot checked yet

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Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

γ-secretase is a protease complex that consists of four transmembrane protein units (nicastrin, presenilin-1/2, PEN2, and Aph-1) and is most commonly associated with cleavage of amyloid precursor protein to produce amyloid-β peptide.

“γ-secretase is a protease complex that consists of four transmembrane protein units (nicastrin, presenilin-1/2, PEN2, and Aph-1) and is most commonly associated with cleavage of amyloid precursor protein (APP) to produce amyloid-β peptide102.”

• cites [102] De Strooper B Aph-1, Pen-2, and Nicastrin with Presenilin Generate an Active γ-Secretase Complex. Neuron. 2003; 38(1): 9– 12. doi: 10.1016/S0896-6273(03)00205-8 12691659 sourceNot checked — no full text of the source

It may state two separate claims as one.

Loss of WASH is associated with decreased surface LDLR and increased plasma cholesterol.

“Loss of WASH is associated with decreased surface LDLR and increased plasma cholesterol98.”

• cites [98] Wijers M, Zanoni P, Liv N, Vos DY, Jäckstein MY, Smit M, Wilbrink S, Wolters JC, van der Veen YT, Huijkman N, Dekker D, Kloosterhuis N, van Dijk TH, Billadeau DD, Kuipers F, Klumperman J, von Eckardstein A, Kuivenhoven JA, van de Sluis B. The hepatic WASH complex is required for efficient plasma LDL and HDL cholesterol clearance. JCI Insight. 2019; 4(11): 126462. doi: 10.1172/jci.insight.126462 31167970 PMC6629119 sourceNot checked yet

It may state two separate claims as one.

Class II mutations can result from misfolding in the ER or from point mutations at key sites for glycosylation, such as recently observed in human N-glycosylation mutants.

“These mutations can result from misfolding in the ER or from point mutations at key sites for glycosylation, such as has been recently observed in human N-glycosylation mutants88.”

• cites [88] van den Boogert MAW, Larsen LE, Ali L, Kuil SD, Chong PLW, Loregger A, Kroon J, Schnitzler JG, Schimmel AWM, Peter J, Levels JHM, Steenbergen G, Morava E, Dallinga-Thie GM, Wevers RA, Kuivenhoven JA, Hand NJ, Zelcer N, Rader DJ, Stroes ESG, Lefeber DJ, Holleboom AG. N-Glycosylation Defects in Humans Lower Low-Density Lipoprotein Cholesterol Through Increased Low-Density Lipoprotein Receptor Expression. Circulation. 2019; 140(4): 280– 292. doi: 10.1161/CIRCULATIONAHA.118.036484 31117816Not checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

BMP1 is a metalloproteinase that plays a central role in remodeling extracellular matrix proteins.

“BMP1 is a metalloproteinase that plays a central role in remodeling extracellular matrix proteins109.”

• cites [109] Vadon-Le Goff S, Hulmes DJS, Moali C. BMP-1/tolloid-like proteinases synchronize matrix assembly with growth factor activation to promote morphogenesis and tissue remodeling. Matrix Biol. 2015; 44-46: 14– 23. doi: 10.1016/j.matbio.2015.02.006 25701650 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

LDLR proteins lacking the cytoplasmic domain still undergo PCSK9-mediated degradation, suggesting that modifications of the cytoplasmic domain or interactions with ubiquitin or adaptor proteins are not involved in routing LDLR:PCSK9 complexes for intracellular degradation.

“LDLR proteins lacking the cytoplasmic domain125 still undergo PCSK9-mediated degradation, suggesting that modifications of the cytoplasmic domain or interactions with ubiquitin or adaptor proteins are not involved in routing LDLR:PCSK9 complexes for intracellular degradation.”

• cites [125] Strøm TB, Holla ØL, Tveten K, Cameron J, Berge KE, Leren TP. Disrupted recycling of the low density lipoprotein receptor by PCSK9 is not mediated by residues of the cytoplasmic domain. Mol Genet Metab. 2010; 101(1): 76– 80. doi: 10.1016/j.ymgme.2010.05.003 20659812 sourceNot checked — no full text of the source

It may state two separate claims as one.

In mice, Asp193 is replaced with a valine residue and mouse LDLR is not cleaved by BMP1.

“although in mice, Asp193 is replaced with a valine residue and mouse LDLR is not cleaved by BMP1110.”

• cites [110] Banerjee S, Andrew RJ, Duff CJ, Fisher K, Jackson CD, Lawrence CB, Maeda N, Greenspan DS, Kellett KAB, Hooper NM. Proteolysis of the low density lipoprotein receptor by bone morphogenetic protein-1 regulates cellular cholesterol uptake. Sci Rep. 2019; 9(1): 11416. doi: 10.1038/s41598-019-47814-0 31388055 PMC6684651 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

The BMP1 cleavage site in human LDLR is between Gly192 and Asp193, and the aspartate residue is critical for cleavage.

“Importantly, the BMP1 cleavage site in human LDLR is between Gly192 and Asp193, with the aspartate residue being critical for cleavage to occur110,”

• cites [110] Banerjee S, Andrew RJ, Duff CJ, Fisher K, Jackson CD, Lawrence CB, Maeda N, Greenspan DS, Kellett KAB, Hooper NM. Proteolysis of the low density lipoprotein receptor by bone morphogenetic protein-1 regulates cellular cholesterol uptake. Sci Rep. 2019; 9(1): 11416. doi: 10.1038/s41598-019-47814-0 31388055 PMC6684651 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

It may state two separate claims as one.

RNF130, also known as GOLIATH, is a RING domain E3 ubiquitin ligase and the most recently reported regulator of LDLR.

“RNF130, also known as GOLIATH, is another RING domain E3 ubiquitin ligase and is the most recently reported regulator of LDLR (Fig. 8C)143.”

• cites [143] Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, De Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circulation Research. 2023; 132(7): 849– 863. doi: 10.1161/CIRCRESAHA.122.321938 36876496 PMC10065965 sourceNot checked yet

Probably not a substantial claim. It may be too vague to check against evidence. It may state two separate claims as one.

Together, the described pathways provide new avenues to design and discover new treatments to treat hypercholesterolemia and FH, combined hyperlipidemias, and lower the incidence of CVD.

“Together, these provide new avenues to design and discover new treatments to treat hypercholesterolemia and FH, combined hyperlipidemias, and lower the incidence of CVD.”

• AssumptionRests on an assumption: The mouse models used to study GOLIATH are informative for human LDLR regulation and cholesterol lowering.

Probably not a substantial claim.

RNF130 and ASGR1 represent potential new targets which would allow stabilization and increased availability of the LDLR.

“Additionally, RNF130 and ASGR1 represent potential new targets which would allow stabilization and increased availability of the LDLR.”

• AssumptionRests on an assumption: The mouse models used to study GOLIATH are informative for human LDLR regulation and cholesterol lowering.

Probably not a substantial claim.

Targeting LDLR to improve its efficiency or function at multiple levels, such as with the combination of statin therapy and PCSK9 inhibitors, may allow for enhanced clearance of LDL from the circulation.

“Targeting the LDLR to improve its efficiency or function at multiple levels of regulation, such as with the combination of statin therapy and PCSK9 inhibitors, may allow for enhanced clearance of LDL from the circulation.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Most RING E3 ligases are cytosolic and only a few, including GOLIATH, possess a transmembrane domain.

“Despite there being over 600 RING E3 ligases144, most are cytosolic and only a few (that includes GOLIATH) possess a transmembrane domain (TMD)145.”

• cites [144] Deshaies RJ, Joazeiro CAP. RING Domain E3 Ubiquitin Ligases. Annu Rev Biochem. 2009; 78(1): 399– 434. doi: 10.1146/annurev.biochem.78.101807.093809 19489725 sourceNot checked — no full text of the source
• cites [145] Yamazaki Y, Schönherr C, Varshney GK, Dogru M, Hallberg B, Palmer RH. Goliath family E3 ligases regulate the recycling endosome pathway via VAMP3 ubiquitylation. EMBO J. 2013; 32(4): 524– 537. doi: 10.1038/emboj.2013.1 23353890 PMC3579141 sourceNot checked — no full text of the source

It may state two separate claims as one.

Targeting GOLIATH in mice resulted in increased LDLR abundance and decreased circulating cholesterol levels.

“Targeting of GOLIATH in mice resulted in increased LDLR abundance and decreased circulating cholesterol levels143,”

• cites [143] Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, De Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circulation Research. 2023; 132(7): 849– 863. doi: 10.1161/CIRCRESAHA.122.321938 36876496 PMC10065965 sourceNot checked yet

It may state two separate claims as one.

IDOL cannot degrade fusion proteins containing the soluble LDLR cytoplasmic tail, yet IDOL can promote degradation of heterologous membrane proteins fused to the LDLR cytoplasmic tail.

“In chimeric reconstitution experiments, it was shown that IDOL cannot degrade fusion proteins containing the soluble LDLR cytoplasmic tail, yet IDOL can promote degradation of heterologous membrane proteins fused to the LDLR cytoplasmic tail136.”

• cites [136] Hong C, Duit S, Jalonen P, Out R, Scheer L, Sorrentino V, Boyadjian R, Rodenburg KW, Foley E, Korhonen L, Lindholm D, Nimpf J, Van Berkel TJC, Tontonoz P, Zelcer N. The E3 Ubiquitin Ligase IDOL Induces the Degradation of the Low Density Lipoprotein Receptor Family Members VLDLR and ApoER2. Journal of Biological Chemistry. 2010; 285(26): 19720– 19726. doi: 10.1074/jbc.M110.123729 20427281 PMC2888382 sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

GOLIATH exhibits a distinct domain architecture of a signal peptide, PA domain, TMD, and RING domain.

“GOLIATH exhibits this distinct domain architecture of a signal peptide, PA domain, TMD, and RING domain143.”

• cites [143] Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, De Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circulation Research. 2023; 132(7): 849– 863. doi: 10.1161/CIRCRESAHA.122.321938 36876496 PMC10065965 sourceNot checked yet

Probably not a substantial claim. It may be too vague to check against evidence.

The extensive myriad of regulatory pathways that dictate abundance, availability, and activity of LDLR provide multiple potential nodes for pharmacologic intervention.

“As we have discussed in this review, the extensive myriad of regulatory pathways that dictate abundance, availability, and activity of the LDLR provide multiple potential nodes for pharmacologic intervention.”

It may state two separate claims as one.

The FERM domain is responsible for IDOL target recognition by binding to a recognition sequence (WxxKNxxSI/MxF) in the cytoplasmic tails of LDLR, VLDLR, and ApoER2 and does not require E3 ligase activity or the RING domain.

“The FERM domain was shown to be responsible for IDOL target recognition by binding to a recognition sequence (WxxKNxxSI/MxF) in the cytoplasmic tails of LDLR, VLDLR, and ApoER2 and does not require the E3 ligase activity or RING domain137.”

• cites [137] Calkin AC, Goult BT, Zhang L, Fairall L, Hong C, Schwabe JWR, Tontonoz P. FERM-dependent E3 ligase recognition is a conserved mechanism for targeted degradation of lipoprotein receptors. Proc Natl Acad Sci U S A. 2011; 108(50): 20107– 20112. doi: 10.1073/pnas.1111589108 22109552 PMC3250164 sourceNot checked — no full text of the source