CoChat
Sign Up
Cited by 109Bacterial Genetics and BiotechnologyAntimicrobial Resistance in StaphylococcusBiochemical and Molecular Research

The second messenger c-di-AMP inhibits the osmolyte uptake system OpuC in Staphylococcus aureus

Open access
Schuster, Christopher F., Bellows, Lauren E., Tosi, Tommaso, Campeotto, Ivan, Corrigan, Rebecca M., Freemont, Paul, Gründling, Angelika·2016·Science Signaling
DOI 10.1126/scisignal.aaf7279PMC PMC5248971
Open this paper in CoChat — free account

Abstract

The second messenger c-di-AMP binds to and inhibits a component of a transporter that helps bacterial cells adapt to osmotic stress.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1126/scisignal.aaf7279

Cites

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Increased c-di-AMP inhibits compatible solute uptake by the Opu-family proteins.

    “Furthermore, increased c-di-AMP inhibits compatible solute uptake by the Opu-family proteins (35, 46).”

    From A Central Role for Magnesium Homeostasis during Adaptation to Osmotic Stress (2022) · cites this paper as [35]

    The Results report reduced carnitine uptake at early time points in a Staphylococcus aureus strain with elevated c-di-AMP, and the Discussion identifies OpuC as the relevant transporter. The paper does not establish inhibition across Opu-family proteins or compatible solutes generally; it says OpuC was the only osmoprotectant uptake system identified as a c-di-AMP target. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • Cyclic di-AMP has been implicated in growth under osmotic stress due to its central role in coordinating K+ homeostasis.

    “Cyclic di-AMP has been implicated in growth under osmotic stress due to its central role in coordinating K+ homeostasis (26, 35, 36).”

    From A Central Role for Magnesium Homeostasis during Adaptation to Osmotic Stress (2022) · cites this paper as [35]

  • The pgpH gdpP double mutant was not rescued by glycine betaine.

    “Interestingly, and consistent with the established inhibition of compatible solute import by c-di-AMP (35, 39, 40), the pgpH gdpP double mutant was not rescued by GB (Fig. S4B).”

    From A Central Role for Magnesium Homeostasis during Adaptation to Osmotic Stress (2022) · cites this paper as [35]

    The citation supports the preceding background point about c-di-AMP inhibiting compatible-solute uptake, not the citing paper’s observation that its pgpH gdpP double mutant was not rescued by glycine betaine; that observation points to Fig. S4B. The source’s Results section reports reduced carnitine uptake in a ΔgdpP strain, but does not address glycine-betaine rescue of a pgpH gdpP double mutant. (LLM, conf=0.78)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

No references could be resolved yet.

Research works printed but not linked: 77

  1. [1]Römling U Great times for small molecules: c-di-AMP, a second messenger candidate in Bacteria and Archaea Sci Signal 2008 1 pe39 18714086
  2. [2]Corrigan RM Gründling A Cyclic di-AMP: another second messenger enters the fray Nat Rev Microbiol 2013 11 513 524 23812326
  3. [3]Witte G Hartung S Buttner K Hopfner KP Structural biochemistry of a bacterial checkpoint protein reveals diadenylate cyclase activity regulated by DNA recombination intermediates Mol Cell 2008 30 167 178 18439896
  4. [4]Rao F See RY Zhang D Toh DC Ji Q Liang ZX YybT is a signaling protein that contains a cyclic dinucleotide phosphodiesterase domain and a GGDEF domain with ATPase activity J Biol Chem 2010 285 473 482 19901023 PMC2804195
  5. [5]Huynh TN Luo S Pensinger D Sauer JD Tong L Woodward JJ An HD-domain phosphodiesterase mediates cooperative hydrolysis of c-di-AMP to affect bacterial growth and virulence Proc Natl Acad Sci U S A 2015 112 E747 756 25583510 PMC4343097
  6. [6]Corrigan RM Abbott JC Burhenne H Kaever V Gründling A c-di-AMP is a new second messenger in Staphylococcus aureus with a role in controlling cell size and envelope stress PLoS Pathog 2011 7 e1002217 21909268 PMC3164647
  7. [7]Corrigan RM Bowman L Willis AR Kaever V Gründling A Cross-talk between two nucleotide-signaling pathways in Staphylococcus aureus J Biol Chem 2015 290 5826 5839 25575594 PMC4342491
  8. [8]Dengler V McCallum N Kiefer P Christen P Patrignani A Vorholt JA Berger-Bächi B Senn MM Mutation in the C-di-AMP cyclase dacA affects fitness and resistance of methicillin resistant Staphylococcus aureus PLoS One 2013 8 e73512 24013956 PMC3754961
  9. [9]Huynh TN Woodward JJ Too much of a good thing: regulated depletion of c-di-AMP in the bacterial cytoplasm Curr Opin Microbiol 2016 30 22 29 26773214 PMC4821758
  10. [10]Mehne FM Gunka K Eilers H Herzberg C Kaever V Stülke J Cyclic di-AMP homeostasis in bacillus subtilis: both lack and high level accumulation of the nucleotide are detrimental for cell growth J Biol Chem 2013 288 2004 2017 23192352 PMC3548507
  11. [11]Woodward JJ Iavarone AT Portnoy DA c-di-AMP secreted by intracellular Listeria monocytogenes activates a host type I interferon response Science 2010 328 1703 1705 20508090 PMC3156580
  12. [12]Whiteley AT Pollock AJ Portnoy DA The PAMP c-di-AMP Is Essential for Listeria monocytogenes Growth in Rich but Not Minimal Media due to a Toxic Increase in (p)ppGpp Cell Host Microbe 2015 17 788 798 26028365 PMC4469362
  13. [13]Sureka K Choi PH Precit M Delince M Pensinger DA Huynh TN Jurado AR Goo YA Sadilek M Iavarone AT Sauer JD The cyclic dinucleotide c-di-AMP is an allosteric regulator of metabolic enzyme function Cell 2014 158 1389 1401 25215494 PMC4166403
  14. [14]Huynh TN Choi PH Sureka K Ledvina HE Campillo J Tong L Woodward JJ Cyclic di-AMP targets the cystathionine beta-synthase domain of the osmolyte transporter OpuC Mol Microbiol 2016 7 5 10.1111/mmi.13456 PMC5118871 27378384 · DOI · Paper page
  15. [15]Zhang L Li W He ZG DarR, a TetR-like transcriptional factor, is a cyclic di-AMP-responsive repressor in Mycobacterium smegmatis J Biol Chem 2013 288 3085 3096 23250743 PMC3561532
  16. [16]Corrigan RM Campeotto I Jeganathan T Roelofs KG Lee VT Gründling A Systematic identification of conserved bacterial c-di-AMP receptor proteins Proc Natl Acad Sci U S A 2013 110 9084 9089 23671116 PMC3670340
  17. [17]Gundlach J Dickmanns A Schröder-Tittmann K Neumann P Kaesler J Kampf J Herzberg C Hammer E Schwede F Kaever V Tittmann K Identification, characterization, and structure analysis of the cyclic di-AMP-binding PII-like signal transduction protein DarA J Biol Chem 2015 290 3069 3080 25433025 PMC4317042
  18. [18]Campeotto I Zhang Y Mladenov MG Freemont PS Gründling A Complex structure and biochemical characterization of the Staphylococcus aureus cyclic diadenylate monophosphate (c-di-AMP)-binding protein PstA, the founding member of a new signal transduction protein family J Biol Chem 2015 290 2888 2901 25505271 PMC4316997
  19. [19]Müller M Hopfner KP Witte G c-di-AMP recognition by Staphylococcus aureus PstA FEBS Lett 2015 589 45 51 25435171
  20. [20]Choi PH Sureka K Woodward JJ Tong L Molecular basis for the recognition of cyclic-di-AMP by PstA, a PII-like signal transduction protein Microbiologyopen 2015 4 361 374 25693966 PMC4475381
  21. [21]Moscoso JA Schramke H Zhang Y Tosi T Dehbi A Jung K Gründling A Binding of Cyclic Di-AMP to the Staphylococcus aureus Sensor Kinase KdpD Occurs via the Universal Stress Protein Domain and Downregulates the Expression of the Kdp Potassium Transporter J Bacteriol 2015 198 98 110 26195599 PMC4686210
  22. [22]Bai Y Yang J Zarrella TM Zhang Y Metzger DW Bai G Cyclic di-AMP impairs potassium uptake mediated by a cyclic di-AMP binding protein in Streptococcus pneumoniae J Bacteriol 2014 196 614 623 24272783 PMC3911161
  23. [23]Kim H Youn SJ Kim SO Ko J Lee JO Choi BS Structural Studies of Potassium Transport Protein KtrA Regulator of Conductance of K+ (RCK) C Domain in Complex with Cyclic Diadenosine Monophosphate (c-di-AMP) J Biol Chem 2015 290 16393 16402 25957408 PMC4481236
  24. [24]Chin KH Liang JM Yang JG Shih MS Tu ZL Wang YC Sun XH Hu NJ Liang ZX Dow JM Ryan RP Structural Insights into the Distinct Binding Mode of Cyclic Di-AMP with SaCpaA_RCK Biochemistry 2015 54 4936 4951 26171638
  25. [25]Krulwich TA Hicks DB Ito M Cation/proton antiporter complements of bacteria: why so large and diverse? Mol Microbiol 2009 74 257 260 19682259 PMC2765581
  26. [26]Epstein W The roles and regulation of potassium in bacteria Prog Nucleic Acid Res Mol Biol 2003 75 293 320 14604015
  27. [27]Wood JM Bacterial osmoregulation: a paradigm for the study of cellular homeostasis Annu Rev Microbiol 2011 65 215 238 21663439
  28. [28]Wood JM Bremer E Csonka LN Kraemer R Poolman B van der Heide T Smith LT Osmosensing and osmoregulatory compatible solute accumulation by bacteria Comp Biochem Physiol A Mol Integr Physiol 2001 130 437 460 11913457
  29. [29]Corrigan RM Bellows LE Wood A Gründling A ppGpp negatively impacts ribosome assembly affecting growth and antimicrobial tolerance in Gram-positive bacteria Proc Natl Acad Sci U S A 2016 PMC4812758 26951678
  30. [30]Roelofs KG Wang J Sintim HO Lee VT Differential radial capillary action of ligand assay for high-throughput detection of protein-metabolite interactions Proc Natl Sci Acad U S A 2011 108 15528 15533 PMC3174574 21876132
  31. [31]Ereno-Orbea J Majtan T Oyenarte I Kraus JP Martinez-Cruz LA Structural basis of regulation and oligomerization of human cystathionine beta-synthase, the central enzyme of transsulfuration Proc Natl Acad Sci U S A 2013 110 E3790 3799 24043838 PMC3791738
  32. [32]Krissinel E Henrick K Inference of macromolecular assemblies from crystalline state J Mol Biol 2007 372 774 797 17681537
  33. [33]Krissinel E Henrick K Secondary-structure matching (SSM), a new tool for fast protein structure alignment in three dimensions Acta Crystallogr D Biol Crystallogr 2004 60 2256 2268 15572779
  34. [34]Lucas M Encinar JA Arribas EA Oyenarte I Garcia IG Kortazar D Fernandez JA Mato JM Martinez-Chantar ML Martinez-Cruz LA Binding of S-methyl-5'-thioadenosine and S-adenosyl-L-methionine to protein MJ0100 triggers an open-to-closed conformational change in its CBS motif pair J Mol Biol 2010 396 800 820 20026078
  35. [35]Ereno-Orbea J Oyenarte I Martinez-Cruz LA CBS domains: Ligand binding sites and conformational variability Arch Biochem Biophys 2013 540 70 81 24161944
  36. [36]Baker NA Sept D Joseph S Holst MJ McCammon JA Electrostatics of nanosystems: application to microtubules and the ribosome Proc Natl Acad Sci U S A 2001 98 10037 10041 11517324 PMC56910
  37. [37]Kiran MD Akiyoshi DE Giacometti A Cirioni O Scalise G Balaban N OpuC-- an ABC transporter that is associated with Staphylococcus aureus pathogenesis Int J Artif Organs 2009 32 600 610 19856269
  38. [38]Kappes RM Kempf B Bremer E Three transport systems for the osmoprotectant glycine betaine operate in Bacillus subtilis: characterization of OpuD J Bacteriol 1996 178 5071 5079 8752321 PMC178300
  39. [39]Angelidis AS Smith GM Three transporters mediate uptake of glycine betaine and carnitine by Listeria monocytogenes in response to hyperosmotic stress Appl Environ Microbiol 2003 69 1013 1022 12571024 PMC143676
  40. [40]Gries CM Bose JL Nuxoll AS Fey PD Bayles KW The Ktr potassium transport system in Staphylococcus aureus and its role in cell physiology, antimicrobial resistance and pathogenesis Mol Microbiol 2013 89 760 773 23815639 PMC3754831
  41. [41]Price-Whelan A Poon CK Benson MA Eidem TT Roux CM Boyd JM Dunman PM Torres VJ Krulwich TA Transcriptional profiling of Staphylococcus aureus during growth in 2 M NaCl leads to clarification of physiological roles for Kdp and Ktr K+ uptake systems MBio 2013 4 PMC3747578 23963175
  42. [42]Kempf B Bremer E Uptake and synthesis of compatible solutes as microbial stress responses to high-osmolality environments Arch Microbiol 1998 170 319 330 9818351
  43. [43]Bremer E Krämer R Bacterial stress responses Storz G Hengge-Aronis R ASM Press Washington, DC 2000 79 97
  44. [44]Wetzel KJ Bjorge D Schwan WR Mutational and transcriptional analyses of the Staphylococcus aureus low-affinity proline transporter OpuD during in vitro growth and infection of murine tissues FEMS Immunol Med Microbiol 2011 61 346 355 21231964 PMC3055929
  45. [45]Schwan WR Lehmann L McCormick J Transcriptional activation of the Staphylococcus aureus putP gene by low-proline-high osmotic conditions and during infection of murine and human tissues Infect Immun 2006 74 399 409 16368996 PMC1346636
  46. [46]Biemans-Oldehinkel E Mahmood NA Poolman B A sensor for intracellular ionic strength Proc Natl Acad Sci U S A 2006 103 10624 10629 16815971 PMC1502282
  47. [47]Mahmood NA Biemans-Oldehinkel E Patzlaff JS Schuurman-Wolters GK Poolman B Ion specificity and ionic strength dependence of the osmoregulatory ABC transporter OpuA J Biol Chem 2006 281 29830 29839 16844687
  48. [48]Mahmood NA Biemans-Oldehinkel E Poolman B Engineering of ion sensing by the cystathionine beta-synthase module of the ABC transporter OpuA J Biol Chem 2009 284 14368 14376 19329426 PMC2682885
  49. [49]Ignoul S Eggermont J CBS domains: structure, function, and pathology in human proteins Am J Physiol Cell Physiol 2005 289 C1369 1378 16275737
  50. [50]Smith WM Pham TH Lei L Dou J Soomro AH Beatson SA Dykes GA Turner MS Heat resistance and salt hypersensitivity in Lactococcus lactis due to spontaneous mutation of llmg_1816 (gdpP) induced by high-temperature growth Appl Environ Microbiol 2012 78 7753 7759 22923415 PMC3485701
  51. [51]Witte CE Whiteley AT Burke TP Sauer JD Portnoy DA Woodward JJ Cyclic di-AMP is critical for Listeria monocytogenes growth, cell wall homeostasis, and establishment of infection MBio 2013 4 e00282 00213 23716572 PMC3663569
  52. [52]Rallu F Gruss A Ehrlich SD Maguin E Acid- and multistress-resistant mutants of Lactococcus lactis: identification of intracellular stress signals Mol Microbiol 2000 35 517 528 10672175
  53. [53]Pozzi C Waters EM Rudkin JK Schaeffer CR Lohan AJ Tong P Loftus BJ Pier GB Fey PD Massey RC O'Gara JP Methicillin resistance alters the biofilm phenotype and attenuates virulence in Staphylococcus aureus device-associated infections PLoS Pathog 2012 8 e1002626 22496652 PMC3320603
  54. [54]Griffiths JM O'Neill AJ Loss of function of the gdpP protein leads to joint beta-lactam/glycopeptide tolerance in Staphylococcus aureus Antimicrob Agents Chemother 2012 56 579 581 21986827 PMC3256080
  55. [55]Smith HO Levine M Two Sequential Repressions of DNA Synthesis in the Establishment of Lysogeny by Phage P22 and Its Mutants Proc Natl Acad Sci U S A 1964 52 356 363 14206603 PMC300284
  56. [56]Townsend DE Wilkinson BJ Proline transport in Staphylococcus aureus: a high-affinity system and a low-affinity system involved in osmoregulation J Bacteriol 1992 174 2702 2710 1556088 PMC205911
  57. [57]Roelofs KG Jones CJ Helman SR Shang X Orr MW Goodson JR Galperin MY Yildiz FH Lee VT Systematic Identification of Cyclic-di-GMP Binding Proteins in Vibrio cholerae Reveals a Novel Class of Cyclic-di-GMP-Binding ATPases Associated with Type II Secretion Systems PLoS Pathog 2015 11 e1005232 26506097 PMC4624772
  58. [58]Monk IR Tree JJ Howden BP Stinear TP Foster TJ Complete Bypass of Restriction Systems for Major Staphylococcus aureus Lineages MBio 2015 6 e00308 00315 26015493 PMC4447248
  59. [59]Monk IR Shah IM Xu M Tan MW Foster TJ Transforming the untransformable: application of direct transformation to manipulate genetically Staphylococcus aureus and Staphylococcus epidermidis MBio 2012 3 PMC3312211 22434850
  60. [60]Lu D Wörmann ME Zhang X Schneewind O Gründling A Freemont PS Structure-based mechanism of lipoteichoic acid synthesis by Staphylococcus aureus LtaS Proc Natl Acad Sci U S A 2009 106 1584 1589 19168632 PMC2635763
  61. [61]Boch J Kempf B Bremer E Osmoregulation in Bacillus subtilis: synthesis of the osmoprotectant glycine betaine from exogenously provided choline J Bacteriol 1994 176 5364 5371 8071213 PMC196722
  62. [62]Fraser KR Harvie D Coote PJ O'Byrne CP Identification and characterization of an ATP binding cassette L-carnitine transporter in Listeria monocytogenes Appl Environ Microbiol 2000 66 4696 4704 11055912 PMC92368
  63. [63]Winter G Lobley CM Prince SM Decision making in xia2 Acta Crystallogr D Biol Crystallogr 2013 69 1260 1273 23793152 PMC3689529
  64. [64]Kabsch W Xds Acta Crystallogr D 2010 66 125 132 20124692 PMC2815665
  65. [65]Winn MD Ballard CC Cowtan KD Dodson EJ Emsley P Evans PR Keegan RM Krissinel EB Leslie AG McCoy A McNicholas SJ Overview of the CCP4 suite and current developments Acta Crystallogr D Biol Crystallogr 2011 67 235 242 21460441 PMC3069738
  66. [66]Adams PD Afonine PV Bunkoczi G Chen VB Davis IW Echols N Headd JJ Hung LW Kapral GJ Grosse-Kunstleve RW McCoy AJ PHENIX: a comprehensive Python-based system for macromolecular structure solution Acta Crystallogr D 2010 66 213 221 20124702 PMC2815670
  67. [67]DiMaio F Advances in Rosetta structure prediction for difficult molecular-replacement problems Acta Crystallogr D Biol Crystallogr 2013 69 2202 2208 24189231 PMC3817693
  68. [68]Kim DE Chivian D Baker D Protein structure prediction and analysis using the Robetta server Nucleic Acids Res 2004 32 W526 531 15215442 PMC441606
  69. [69]McCoy AJ Grosse-Kunstleve RW Adams PD Winn MD Storoni LC Read RJ Phaser crystallographic software Journal of applied crystallography 2007 40 658 674 19461840 PMC2483472
  70. [70]Vagin AA Steiner RA Lebedev AA Potterton L McNicholas S Long F Murshudov GN REFMAC5 dictionary: organization of prior chemical knowledge and guidelines for its use Acta crystallographica Section D, Biological crystallography 2004 60 2184 2195 15572771
  71. [71]Emsley P Lohkamp B Scott WG Cowtan K Features and development of Coot Acta Crystallogr D 2010 66 486 501 20383002 PMC2852313
  72. [72]Chen VB Arendall WB 3rd Headd JJ Keedy DA Immormino RM Kapral GJ Murray LW Richardson JS Richardson DC MolProbity: all-atom structure validation for macromolecular crystallography Acta Crystallogr D Biol Crystallogr 2010 66 12 21 20057044 PMC2803126
  73. [73]Dolinsky TJ Czodrowski P Li H Nielsen JE Jensen JH Klebe G Baker NA PDB2PQR: expanding and upgrading automated preparation of biomolecular structures for molecular simulations Nucleic Acids Res 2007 35 W522 525 17488841 PMC1933214
  74. [74]Gille C Frommel C STRAP: editor for STRuctural Alignments of Proteins Bioinformatics 2001 17 377 378 11301311
  75. [75]Lee CY Buranen SL Ye ZH Construction of single-copy integration vectors for Staphylococcus aureus Gene 1991 103 101 105 1652539
  76. [76]Lee VT Matewish JM Kessler JL Hyodo M Hayakawa Y Lory S A cyclic-di-GMP receptor required for bacterial exopolysaccharide production Mol Microbiol 2007 65 1474 1484 17824927 PMC2170427
  77. [77]Boles BR Thoendel M Roth AJ Horswill AR Identification of genes involved in polysaccharide-independent Staphylococcus aureus biofilm formation PLoS One 2010 5 e10146 20418950 PMC2854687

Cited by

Sorted by citations

Authors
Schuster, C. F., Bellows, L. E., Tosi, T., Campeotto, I., Corrigan, R. M., Freemont, P., & Gründling, A.
Affiliations
Imperial College London (GB)
Corresponding author
  • Schuster, Christopher F.
  • Bellows, Lauren E.
  • Gründling, Angelika
ORCID
Venue
Science Signaling
Publisher
American Association for the Advancement of Science (AAAS)
Published
2016-08-16
Volume
9
Issue
441
Pages
ra81-ra81
ISSN
  • 1937-9145 (ISSN-L)
  • 1945-0877
DOI
10.1126/scisignal.aaf7279
PMC
PMC5248971
OpenAlex
W2507323902
Cited by
109
References
0
Citations by year
2026: 6 · 2025: 7 · 2024: 13 · 2023: 17 · 2022: 10 · 2021: 8 · 2020: 15 · 2019: 14 · 2018: 7 · 2017: 9 · 2016: 3
FWCI
8.89
Type
journal article
Language
en
Open access
Licence
www.sciencemag.org/about/science-licenses-journal-article-reuse (vor, 365 d)
Locations
  • Science Signaling (publishedVersion)
  • PubMed (publishedVersion)
  • White Rose Research Online (University of Leeds, The University of Sheffield, University of York) (acceptedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • Nottingham Trent University's Institutional Repository (Nottingham Trent Repository) (submittedVersion)
  • Spiral (Imperial College London) (submittedVersion)
Funders
  • European Research Council (260371)
  • Wellcome Trust (100289)
  • Deutsche Forschungsgemeinschaft (DFG) (SCHU 3159/1-1)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
  • Health Sciences › Medicine › Infectious Diseases › Antimicrobial Resistance in Staphylococcus
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Molecular Research
Keywords
c-di-AMP, Staphylococcus aureus, osmotic stress, osmolytes, carnitine uptake, potassium uptake, second messenger signaling, ATPase, CBS domain, protein inhibition, crystal structure
MeSH terms
Protein Domains, Bacterial Proteins, Carnitine, Osmotic Pressure, Staphylococcus aureus, Dinucleoside Phosphates, Second Messenger Systems, Crystallography, X-Ray, ATP-Binding Cassette Transporters

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review