Unconventional secretion of Acb1 is mediated by autophagosomes
Open accessAbstract
Starving Dictyostelium discoideum cells secrete AcbA, an acyl coenzyme A–binding protein (ACBP) that lacks a conventional signal sequence for entering the endoplasmic reticulum (ER). Secretion of AcbA in D. discoideum requires the Golgi-associated protein GRASP. In this study, we report that starvation-induced secretion of Acb1, the Saccharomyces cerevisiae ACBP orthologue, also requires GRASP (Grh1). This highlights the conserved function of GRASP in unconventional secretion. Although genes required for ER to Golgi or Golgi to cell surface transport are not required for Acb1 secretion in yeast, this process involves autophagy genes and the plasma membrane t-SNARE, Sso1. Inhibiting transport to vacuoles does not affect Acb1 secretion. In sum, our experiments reveal a unique secretory pathway where autophagosomes containing Acb1 evade fusion with the vacuole to prevent cargo degradation. We propose that these autophagosome intermediates fuse with recycling endosomes instead to form multivesicular body carriers that then fuse with the plasma membrane to release cargo.
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.
Integrity signals
Registry
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.
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?
Autophagy mediates the secretion of proteins such as IL-1β and IL-18 that lack a leader peptide.
“Autophagy has also been recognized to mediate the secretion of proteins (34) – such as IL-1β and IL-18 (35, 36) – that would otherwise not enter the classical secretory pathway due to lack of a leader peptide.”
From Macrophage Cytokines: Involvement in Immunity and Infectious Diseases (2014) · cites this paper as [34]
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: 49
- Aalto M.K. Ronne H. Keränen S. 1993 Yeast syntaxins Sso1p and Sso2p belong to a family of related membrane proteins that function in vesicular transport. EMBO J. 12: 4095– 4104 8223426 PMC413702
- Abeliovich H. Darsow T. Emr S.D. 1999 Cytoplasm to vacuole trafficking of aminopeptidase I requires a t-SNARE-Sec1p complex composed of Tlg2p and Vps45p. EMBO J. 18: 6005– 6016 10.1093/emboj/18.21.6005 10545112 PMC1171666 · DOI · Paper page
- Anjard C. Loomis W.F. 2005 Peptide signaling during terminal differentiation of Dictyostelium. Proc. Natl. Acad. Sci. USA. 102: 7607– 7611 10.1073/pnas.0501820102 15897458 PMC1140433 · DOI
- Anjard C. Zeng C. Loomis W.F. Nellen W. 1998 Signal transduction pathways leading to spore differentiation in Dictyostelium discoideum. Dev. Biol. 193: 146– 155 10.1006/dbio.1997.8804 9473320 · DOI
- Anjard C. Su Y. Loomis W.F. 2009 Steroids initiate a signaling cascade that triggers rapid sporulation in Dictyostelium. Development. 136: 803– 812 10.1242/dev.032607 19176583 PMC2685946 · DOI
- Babst M. Sato T.K. Banta L.M. Emr S.D. 1997 Endosomal transport function in yeast requires a novel AAA-type ATPase, Vps4p. EMBO J. 16: 1820– 1831 10.1093/emboj/16.8.1820 9155008 PMC1169785 · DOI
- Barlowe C. Orci L. Yeung T. Hosobuchi M. Hamamoto S. Salama N. Rexach M.F. Ravazzola M. Amherdt M. Schekman R. 1994 COPII: a membrane coat formed by Sec proteins that drive vesicle budding from the endoplasmic reticulum. Cell. 77: 895– 907 10.1016/0092-8674(94)90138-4 8004676 · DOI
- Becherer K.A. Rieder S.E. Emr S.D. Jones E.W. 1996 Novel syntaxin homologue, Pep12p, required for the sorting of lumenal hydrolases to the lysosome-like vacuole in yeast. Mol. Biol. Cell. 7: 579– 594 8730101 PMC275911
- Behnia R. Barr F.A. Flanagan J.J. Barlowe C. Munro S. 2007 The yeast orthologue of GRASP65 forms a complex with a coiled-coil protein that contributes to ER to Golgi traffic. J. Cell Biol. 176: 255– 261 10.1083/jcb.200607151 17261844 PMC2063951 · DOI
- Carr C.M. Grote E. Munson M. Hughson F.M. Novick P.J. 1999 Sec1p binds to SNARE complexes and concentrates at sites of secretion. J. Cell Biol. 146: 333– 344 10.1083/jcb.146.2.333 10427089 PMC3206579 · DOI
- Costa E. Guidotti A. 1991 Diazepam binding inhibitor (DBI): a peptide with multiple biological actions. Life Sci. 49: 325– 344 10.1016/0024-3205(91)90440-M 1649940 · DOI
- Darsow T. Rieder S.E. Emr S.D. 1997 A multispecificity syntaxin homologue, Vam3p, essential for autophagic and biosynthetic protein transport to the vacuole. J. Cell Biol. 138: 517– 529 10.1083/jcb.138.3.517 9245783 PMC2141632 · DOI
- Fader C.M. Colombo M.I. 2006 Multivesicular bodies and autophagy in erythrocyte maturation. Autophagy. 2: 122– 125 16874060
- Flieger O. Engling A. Bucala R. Lue H. Nickel W. Bernhagen J. 2003 Regulated secretion of macrophage migration inhibitory factor is mediated by a non-classical pathway involving an ABC transporter. FEBS Lett. 551: 78– 86 10.1016/S0014-5793(03)00900-1 12965208 · DOI
- Graham T.R. Emr S.D. 1991 Compartmental organization of Golgi-specific protein modification and vacuolar protein sorting events defined in a yeast sec18 (NSF) mutant. J. Cell Biol. 114: 207– 218 10.1083/jcb.114.2.207 2071670 PMC2289075 · DOI
- Grundmann U. Abel K.J. Bohn H. Löbermann H. Lottspeich F. Küpper H. 1988 Characterization of cDNA encoding human placental anticoagulant protein (PP4): homology with the lipocortin family. Proc. Natl. Acad. Sci. USA. 85: 3708– 3712 10.1073/pnas.85.11.3708 2967495 PMC280287 · DOI
- Haas A. Scheglmann D. Lazar T. Gallwitz D. Wickner W. 1995 The GTPase Ypt7p of Saccharomyces cerevisiae is required on both partner vacuoles for the homotypic fusion step of vacuole inheritance. EMBO J. 14: 5258– 5270 7489715 PMC394635
- Jäntti J. Aalto M.K. Oyen M. Sundqvist L. Keränen S. Ronne H. 2002 Characterization of temperature-sensitive mutations in the yeast syntaxin 1 homologues Sso1p and Sso2p, and evidence of a distinct function for Sso1p in sporulation. J. Cell Sci. 15: 409– 420 11839791
- Joliot A. Maizel A. Rosenberg D. Trembleau A. Dupas S. Volovitch M. Prochiantz A. 1998 Identification of a signal sequence necessary for the unconventional secretion of Engrailed homeoprotein. Curr. Biol. 8: 856– 863 10.1016/S0960-9822(07)00346-6 9705930 · DOI
- Katzmann D.J. Stefan C.J. Babst M. Emr S.D. 2003 Vps27 recruits ESCRT machinery to endosomes during MVB sorting. J. Cell Biol. 162: 413– 423 10.1083/jcb.200302136 12900393 PMC2172707 · DOI
- Kinseth M.A. Anjard C. Fuller D. Guizzunti G. Loomis W.F. Malhotra V. 2007 The Golgi-associated protein GRASP is required for unconventional protein secretion during development. Cell. 130: 524– 534 10.1016/j.cell.2007.06.029 17655921 · DOI
- Klionsky D.J. Emr S.D. 2000 Autophagy as a regulated pathway of cellular degradation. Science. 290: 1717– 1721 10.1126/science.290.5497.1717 11099404 PMC2732363 · DOI
- Kuchler K. Sterne R.E. Thorner J. 1989 Saccharomyces cerevisiae STE6 gene product: a novel pathway for protein export in eukaryotic cells. EMBO J. 8: 3973– 3984 2686977 PMC401572
- Kuma A. Mizushima N. Ishihara N. Ohsumi Y. 2002 Formation of the approximately 350-kDa Apg12-Apg5.Apg16 multimeric complex, mediated by Apg16 oligomerization, is essential for autophagy in yeast. J. Biol. Chem. 277: 18619– 18625 10.1074/jbc.M111889200 11897782 · DOI
- Liang C. Lee J.S. Inn K.S. Gack M.U. Li Q. Roberts E.A. Vergne I. Deretic V. Feng P. Akazawa C. Jung J.U. 2008 Beclin1-binding UVRAG targets the class C Vps complex to coordinate autophagosome maturation and endocytic trafficking. Nat. Cell Biol. 10: 776– 787 10.1038/ncb1740 18552835 PMC2878716 · DOI · Paper page
- Longtine M.S. McKenzie A. III Demarini D.J. Shah N.G. Wach A. Brachat A. Philippsen P. Pringle J.R. 1998 Additional modules for versatile and economical PCR-based gene deletion and modification in Saccharomyces cerevisiae. Yeast. 14: 953– 961 10.1002/(SICI)1097-0061(199807)14:10<953::AID-YEA293>3.0.CO;2-U 9717241 · DOI
- Lum J.J. DeBerardinis R.J. Thompson C.B. Shah N.G. Wach A. Brachat A. Lum J.J. DeBerardinis R.J. Thompson C.B. 2005 Autophagy in metazoans: cell survival in the land of plenty. Nat. Rev. Mol. Cell Biol. 6: 439– 448 10.1038/nrm1660 15928708 · DOI
- Luo Z. Gallwitz D. 2003 Biochemical and genetic evidence for the involvement of yeast Ypt6-GTPase in protein retrieval to different Golgi compartments. J. Biol. Chem. 278: 791– 799 10.1074/jbc.M209120200 12401784 · DOI
- Lutomski D. Fouillit M. Bourin P. Mellottée D. Denize N. Pontet M. Bladier D. Caron M. Joubert-Caron R. 1997 Externalization and binding of galectin-1 on cell surface of K562 cells upon erythroid differentiation. Glycobiology. 7: 1193– 1199 10.1093/glycob/7.8.1193 9455920 · DOI
- Manjithaya R. Anjard C. Loomis W.F. Subramani S. 2010 Unconventional secretion of Pichia pastoris Acb1 is dependent on GRASP protein, peroxisomal functions, and autophagosome formation. J. Cell Biol. 188: 537– 546 20156962 PMC2828923
- Menon R.P. Hughes R.C. 1999 Determinants in the N-terminal domains of galectin-3 for secretion by a novel pathway circumventing the endoplasmic reticulum-Golgi complex. Eur. J. Biochem. 264: 569– 576 10.1046/j.1432-1327.1999.00671.x 10491105 · DOI
- Mizushima N. Noda T. Yoshimori T. Tanaka Y. Ishii T. George M.D. Klionsky D.J. Ohsumi M. Ohsumi Y. 1998 A protein conjugation system essential for autophagy. Nature. 395: 395– 398 10.1038/26506 9759731 · DOI
- Nakatogawa H. Ichimura Y. Ohsumi Y. 2007 Atg8, a ubiquitin-like protein required for autophagosome formation, mediates membrane tethering and hemifusion. Cell. 130: 165– 178 10.1016/j.cell.2007.05.021 17632063 · DOI
- Nichols B.J. Holthuis J.C. Pelham H.R. 1998 The Sec1p homologue Vps45p binds to the syntaxin Tlg2p. Eur. J. Cell Biol. 77: 263– 268 9930650
- Nickel W. Seedorf M. 2008 Unconventional mechanisms of protein transport to the cell surface of eukaryotic cells. Annu. Rev. Cell Dev. Biol. 24: 287– 308 10.1146/annurev.cellbio.24.110707.175320 18590485 · DOI
- Reggiori F. Wang C.W. Nair U. Shintani T. Abeliovich H. Klionsky D.J. 2004 Early stages of the secretory pathway, but not endosomes, are required for Cvt vesicle and autophagosome assembly in Saccharomyces cerevisiae. Mol. Biol. Cell. 15: 2189– 2204 10.1091/mbc.E03-07-0479 15004240 PMC404015 · DOI
- Robinson J.S. Klionsky D.J. Banta L.M. Emr S.D. 1988 Protein sorting in Saccharomyces cerevisiae: isolation of mutants defective in the delivery and processing of multiple vacuolar hydrolases. Mol. Cell. Biol. 8: 4936– 4948 3062374 PMC365587
- Rubartelli A. Cozzolino F. Talio M. Sitia R. 1990 A novel secretory pathway for interleukin-1 beta, a protein lacking a signal sequence. EMBO J. 9: 1503– 1510 2328723 PMC551842
- Sata M. Donaldson J.G. Moss J. Vaughan M. 1998 Brefeldin A-inhibited guanine nucleotide-exchange activity of Sec7 domain from yeast Sec7 with yeast and mammalian ADP ribosylation factors. Proc. Natl. Acad. Sci. USA. 95: 4204– 4208 10.1073/pnas.95.8.4204 9539714 PMC22466 · DOI
- Sato T.K. Darsow T. Emr S.D. 1998 Vam7p, a SNAP-25-like molecule, and Vam3p, a syntaxin homolog, function together in yeast vacuolar protein trafficking. Mol. Cell. Biol. 18: 5308– 5319 9710615 PMC109116
- Schimmöller F. Riezman H. 1993 Involvement of Ypt7p, a small GTPase, in traffic from late endosome to the vacuole in yeast. J. Cell Sci. 106: 823– 830 8308065
- Schotman H. Karhinen L. Rabouille C. 2008 dGRASP-mediated noncanonical integrin secretion is required for Drosophila epithelial remodeling. Dev. Cell. 14: 171– 182 10.1016/j.devcel.2007.12.006 18267086 · DOI
- Seelenmeyer C. Stegmayer C. Nickel W. 2008 Unconventional secretion of fibroblast growth factor 2 and galectin-1 does not require shedding of plasma membrane-derived vesicles. FEBS Lett. 582: 1362– 1368 10.1016/j.febslet.2008.03.024 18371311 · DOI
- Shintani T. Klionsky D.J. 2004 Cargo proteins facilitate the formation of transport vesicles in the cytoplasm to vacuole targeting pathway. J. Biol. Chem. 279: 29889– 29894 10.1074/jbc.M404399200 15138258 PMC1712665 · DOI
- Simons M. Raposo G. 2009 Exosomes—vesicular carriers for intercellular communication. Curr. Opin. Cell Biol. 21: 575– 581 10.1016/j.ceb.2009.03.007 19442504 · DOI
- Suzuki K. Kirisako T. Kamada Y. Mizushima N. Noda T. Ohsumi Y. 2001 The pre-autophagosomal structure organized by concerted functions of APG genes is essential for autophagosome formation. EMBO J. 20: 5971– 5981 10.1093/emboj/20.21.5971 11689437 PMC125692 · DOI
- Temmerman K. Ebert A.D. Müller H.M. Sinning I. Tews I. Nickel W. 2008 A direct role for phosphatidylinositol-4,5-bisphosphate in unconventional secretion of fibroblast growth factor 2. Traffic. 9: 1204– 1217 10.1111/j.1600-0854.2008.00749.x 18419755 · DOI
- Théry C. Ostrowski M. Segura E. 2009 Membrane vesicles as conveyors of immune responses. Nat. Rev. Immunol. 9: 581– 593 10.1038/nri2567 19498381 · DOI
- Xie Z. Nair U. Klionsky D.J. 2008 Atg8 controls phagophore expansion during autophagosome formation. Mol. Biol. Cell. 19: 3290– 3298 10.1091/mbc.E07-12-1292 18508918 PMC2488302 · DOI · Paper page
Cited by
Sorted by citations
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition).
Klionsky, D. J., Abdelmohsen, K., Abe, A., Abedin, M. J., Abeliovich, H., Acevedo Arozena, A., Adachi, H., Adams, C. M., Adams, P. D., Adeli, K., et al. (2016) · Autophagy · doi:10.1080/15548627.2015.1100356 · Cited by 5,894 · see citing works
Biological Functions of Autophagy Genes: A Disease Perspective
Levine, B., & Kroemer, G. (2019) · Cell · doi:10.1016/j.cell.2018.09.048 · Cited by 2,832 · see citing works
Macrophage Cytokines: Involvement in Immunity and Infectious Diseases
Arango Duque, G., & Descoteaux, A. (2014) · Frontiers in Immunology · doi:10.3389/fimmu.2014.00491 · Cited by 2,708 · see citing works
“Autophagy has also been recognized to mediate the secretion of proteins (34) – such as IL-1β and IL-18 (35, 36) – that would otherwise not enter the classical secretory pathway due to lack of a leader peptide.”
BackgroundKlionsky, D. J., Abdel-Aziz, A. K., Abdelfatah, S., Abdellatif, M., Abdoli, A., Abel, S., Abeliovich, H., Abildgaard, M. H., Abudu, Y. P., Acevedo-Arozena, A., et al. (2021) · Autophagy · doi:10.1080/15548627.2020.1797280 · Cited by 2,622 · see citing works
Emerging regulation and functions of autophagy
Boya, P., Reggiori, F., & Codogno, P. (2013) · Nature Cell Biology · doi:10.1038/ncb2788 · Cited by 1,216 · see citing works
Autophagy‐based unconventional secretory pathway for extracellular delivery of IL‐1β
Dupont, N., Jiang, S., Pilli, M., Ornatowski, W., Bhattacharya, D., & Deretic, V. (2011) · The EMBO Journal · doi:10.1038/emboj.2011.398 · Cited by 967 · see citing works
A new pathway for mitochondrial quality control: Mitochondrial-derived vesicles
Sugiura, A., McLelland, G., Fon, E. A., & McBride, H. M. (2014) · The EMBO Journal · doi:10.15252/embj.201488104 · Cited by 862 · see citing works
α-Synuclein impairs macroautophagy: implications for Parkinson’s disease
Winslow, A. R., Chen, C.-W., Corrochano, S., Acevedo-Arozena, A., Gordon, D. E., Peden, A. A., Lichtenberg, M., Menzies, F. M., Ravikumar, B., Imarisio, S., et al. (2010) · Journal of Cell Biology · doi:10.1083/jcb.201003122 · Cited by 825 · see citing works
Caielli, S., Athale, S., Domic, B., Murat, E., Chandra, M., Banchereau, R., Baisch, J., Phelps, K., Clayton, S., Gong, M., et al. (2016) · Journal of Experimental Medicine · doi:10.1084/jem.20151876 · Cited by 501 · see citing works
Autophagy Proteins Regulate the Secretory Component of Osteoclastic Bone Resorption
DeSelm, C. J., Miller, B. C., Zou, W., Beatty, W. L., van Meel, E., Takahata, Y., Klumperman, J., Tooze, S. A., Teitelbaum, S. L., & Virgin, H. W. (2011) · Developmental Cell · doi:10.1016/j.devcel.2011.08.016 · Cited by 487 · see citing works
Autophagy in osteoblasts is involved in mineralization and bone homeostasis
Nollet, M., Santucci-Darmanin, S., Breuil, V., Al-Sahlanee, R., Cros, C., Topi, M., Momier, D., Samson, M., Pagnotta, S., Cailleteau, L., et al. (2014) · Autophagy · doi:10.4161/auto.36182 · Cited by 422 · see citing works
Autophagy in Antimicrobial Immunity
Gomes, L. C., & Dikic, I. (2014) · Molecular Cell · doi:10.1016/j.molcel.2014.03.009 · Cited by 350 · see citing works
Freigang, S., Ampenberger, F., Spohn, G., Heer, S., Shamshiev, A. T., Kisielow, J., Hersberger, M., Yamamoto, M., Bachmann, M. F., & Kopf, M. (2011) · European Journal of Immunology · doi:10.1002/eji.201041316 · Cited by 300 · see citing works
PIKfyve inhibition increases exosome release and induces secretory autophagy
Hessvik, N. P., Øverbye, A., Brech, A., Torgersen, M. L., Jakobsen, I. S., Sandvig, K., & Llorente, A. (2016) · Cellular and Molecular Life Sciences · doi:10.1007/s00018-016-2309-8 · Cited by 269 · see citing works
Minakaki, G., Menges, S., Kittel, A., Emmanouilidou, E., Schaeffner, I., Barkovits, K., Bergmann, A., Rockenstein, E., Adame, A., Marxreiter, F., et al. (2018) · Autophagy · doi:10.1080/15548627.2017.1395992 · Cited by 272 · see citing works
Loss of autophagy in hypothalamic POMC neurons impairs lipolysis
Kaushik, S., Arias, E., Kwon, H., Lopez, N. M., Athonvarangkul, D., Sahu, S., Schwartz, G. J., Pessin, J. E., & Singh, R. (2012) · The EMBO Reports · doi:10.1038/embor.2011.260 · Cited by 212 · see citing works
Quality and quantity control at the endoplasmic reticulum
Hegde, R. S., & Ploegh, H. L. (2010) · Current Opinion in Cell Biology · doi:10.1016/j.ceb.2010.05.005 · Cited by 157 · see citing works
Eaten alive: novel insights into autophagy from multicellular model systems
Zhang, H., & Baehrecke, E. H. (2015) · Trends in Cell Biology · doi:10.1016/j.tcb.2015.03.001 · Cited by 102 · see citing works
Protein Secretion: Unconventional Exit by Exophagy
Abrahamsen, H., & Stenmark, H. (2010) · Current Biology · doi:10.1016/j.cub.2010.03.011 · Cited by 58 · see citing works
- Authors
- Duran, J. M., Anjard, C., Stefan, C., Loomis, W. F., & Malhotra, V.
- Affiliations
- Center for Genomic Regulation, Barcelona 08003, Spain 1
- University of California San Diego (US)
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14850 3
- Institució Catalana de Recerca i Estudis Avançats (ES)
- Corresponding author
- Malhotra, Vivek
- Venue
- Journal of Cell Biology
- Publisher
- Rockefeller University Press
- Published
- 2010-02-15
- Volume
- 188
- Issue
- 4
- Pages
- 527-536
- ISSN
- 0021-9525 (ISSN-L)
- 1540-8140
- PMC
- PMC2828925
- OpenAlex
- W1993690543
- Cited by
- 433
- References
- 0
- Citations by year
- 2026: 16 · 2025: 24 · 2024: 20 · 2023: 18 · 2022: 21 · 2021: 34 · 2020: 29 · 2019: 20 · 2018: 30 · 2017: 24 · 2016: 32 · 2015: 26 · 2014: 25 · 2013: 34 · 2012: 31
- FWCI
- 15.81
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- cc-by-nc-sa
- Locations
- The Journal of Cell Biology (publishedVersion, cc-by-nc-sa)
- Europe PMC (PubMed Central) (publishedVersion, cc-by-nc-sa)
- PubMed Central (publishedVersion, cc-by-nc-sa)
- PubMed (publishedVersion)
- UCL Discovery (University College London) (submittedVersion)
- Funders
- National Institute of General Medical Sciences (GM78175, R01GM078175)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Cellular transport and secretion
- Health Sciences › Medicine › Epidemiology › Autophagy in Disease and Therapy
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Fungal and yeast genetics research
- Keywords
- unconventional secretion, GRASP, autophagosomes, autophagy, t-SNARE, recycling endosomes, multivesicular bodies, vacuole fusion, Dictyostelium discoideum, Saccharomyces cerevisiae, secretory pathway
- MeSH terms
- Amino Acid Sequence, Autophagy, Carrier Proteins, Cell Membrane, Genes, Fungal, Golgi Apparatus, Membrane Fusion, Models, Biological, Molecular Sequence Data, Peptides, Phagosomes, Saccharomyces cerevisiae, Vacuoles, Saccharomyces cerevisiae Proteins, Intercellular Signaling Peptides and Proteins, Qa-SNARE Proteins, Secretory Pathway, Multivesicular Bodies
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
