{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T13:56:18Z","timestamp":1791122178994,"version":"4.1.0"},"reference-count":40,"publisher":"National Academy of Sciences","issue":"33","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2013,8,13]]},"abstract":"<jats:p>The sequential steps in the alphavirus membrane fusion pathway have been postulated based on the prefusion and postfusion crystal structures of the viral fusion protein E1 in conjunction with biochemical studies. However, the molecular structures of the hypothesized fusion intermediates have remained obscure due to difficulties inherent in the dynamic nature of the process. We developed an experimental system that uses liposomes as the target membrane to capture Sindbis virus, a prototypical alphavirus, in its membrane-binding form at pH 6.4. Cryoelectron micrograph analyses and 3D reconstructions showed that the virus retains its overall icosahedral structure at this mildly acidic pH, except in the membrane-binding region, where monomeric E1 associates with the target membrane and the E2 glycoprotein retains its original trimeric organization. The remaining E2 trimers may hinder E1 homotrimerization and are a potential target for antiviral drugs.<\/jats:p>","DOI":"10.1073\/pnas.1301911110","type":"journal-article","created":{"date-parts":[[2013,7,30]],"date-time":"2013-07-30T00:11:18Z","timestamp":1375143078000},"page":"13362-13367","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":40,"title":["Characterization of an early-stage fusion intermediate of Sindbis virus using cryoelectron microscopy"],"prefix":"10.1073","volume":"110","author":[{"given":"Sheng","family":"Cao","sequence":"first","affiliation":[{"name":"Institute of Molecular Virology, University of Minnesota, Minneapolis, MN 55455;"},{"name":"Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Molecular Virology, University of Minnesota, Minneapolis, MN 55455;"},{"name":"Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455; and"},{"name":"Characterization Facility, College of Science and Engineering, University of Minnesota, Minneapolis, MN 55455"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2013,7,29]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"crossref","first-page":"404","DOI":"10.1083\/jcb.84.2.404","article-title":"On the entry of Semliki forest virus into BHK-21 cells","volume":"84","author":"Helenius A","year":"1980","unstructured":"A Helenius, J Kartenbeck, K Simons, E Fries, On the entry of Semliki forest virus into BHK-21 cells. J Cell Biol 84, 404\u2013420 (1980).","journal-title":"J Cell Biol"},{"key":"e_1_3_4_2_2","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/S0065-3527(08)60059-7","article-title":"Membrane fusion and the alphavirus life cycle","volume":"45","author":"Kielian M","year":"1995","unstructured":"M Kielian, Membrane fusion and the alphavirus life cycle. Adv Virus Res 45, 113\u2013151 (1995).","journal-title":"Adv Virus Res"},{"key":"e_1_3_4_3_2","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/j.tim.2009.08.002","article-title":"Dealing with low pH: Entry and exit of alphaviruses and flaviviruses","volume":"17","author":"S\u00e1nchez-San Mart\u00edn C","year":"2009","unstructured":"C S\u00e1nchez-San Mart\u00edn, CY Liu, M Kielian, Dealing with low pH: Entry and exit of alphaviruses and flaviviruses. Trends Microbiol 17, 514\u2013521 (2009).","journal-title":"Trends Microbiol"},{"key":"e_1_3_4_4_2","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1128\/mr.58.3.491-562.1994","article-title":"The alphaviruses: Gene expression, replication, and evolution","volume":"58","author":"Strauss JH","year":"1994","unstructured":"JH Strauss, EG Strauss, The alphaviruses: Gene expression, replication, and evolution. Microbiol Rev 58, 491\u2013562 (1994).","journal-title":"Microbiol Rev"},{"key":"e_1_3_4_5_2","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1002\/j.1460-2075.1993.tb05703.x","article-title":"Membrane fusion of Semliki Forest virus in a model system: Correlation between fusion kinetics and structural changes in the envelope glycoprotein","volume":"12","author":"Bron R","year":"1993","unstructured":"R Bron, JM Wahlberg, H Garoff, J Wilschut, Membrane fusion of Semliki Forest virus in a model system: Correlation between fusion kinetics and structural changes in the envelope glycoprotein. EMBO J 12, 693\u2013701 (1993).","journal-title":"EMBO J"},{"key":"e_1_3_4_6_2","doi-asserted-by":"crossref","first-page":"796","DOI":"10.3390\/v2040796","article-title":"Alphavirus entry and membrane fusion","volume":"2","author":"Kielian M","year":"2010","unstructured":"M Kielian, C Chanel-Vos, M Liao, Alphavirus entry and membrane fusion. Viruses 2, 796\u2013825 (2010).","journal-title":"Viruses"},{"key":"e_1_3_4_7_2","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1128\/jvi.52.1.281-283.1984","article-title":"Role of cholesterol in fusion of Semliki Forest virus with membranes","volume":"52","author":"Kielian MC","year":"1984","unstructured":"MC Kielian, A Helenius, Role of cholesterol in fusion of Semliki Forest virus with membranes. J Virol 52, 281\u2013283 (1984).","journal-title":"J Virol"},{"key":"e_1_3_4_8_2","doi-asserted-by":"crossref","first-page":"8476","DOI":"10.1128\/JVI.73.10.8476-8484.1999","article-title":"Low-pH-dependent fusion of Sindbis virus with receptor-free cholesterol- and sphingolipid-containing liposomes","volume":"73","author":"Smit JM","year":"1999","unstructured":"JM Smit, R Bittman, J Wilschut, Low-pH-dependent fusion of Sindbis virus with receptor-free cholesterol- and sphingolipid-containing liposomes. J Virol 73, 8476\u20138484 (1999).","journal-title":"J Virol"},{"key":"e_1_3_4_9_2","doi-asserted-by":"crossref","first-page":"3273","DOI":"10.1073\/pnas.77.6.3273","article-title":"pH-dependent fusion between the Semliki Forest virus membrane and liposomes","volume":"77","author":"White J","year":"1980","unstructured":"J White, A Helenius, pH-dependent fusion between the Semliki Forest virus membrane and liposomes. Proc Natl Acad Sci USA 77, 3273\u20133277 (1980).","journal-title":"Proc Natl Acad Sci USA"},{"key":"e_1_3_4_10_2","doi-asserted-by":"crossref","first-page":"9327","DOI":"10.1128\/JVI.05015-11","article-title":"The structure of Barmah Forest virus as revealed by cryo-electron microscopy at a 6-angstrom resolution has detailed transmembrane protein architecture and interactions","volume":"85","author":"Kostyuchenko VA","year":"2011","unstructured":"VA Kostyuchenko, et al., The structure of Barmah Forest virus as revealed by cryo-electron microscopy at a 6-angstrom resolution has detailed transmembrane protein architecture and interactions. J Virol 85, 9327\u20139333 (2011).","journal-title":"J Virol"},{"key":"e_1_3_4_11_2","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S1097-2765(00)80421-9","article-title":"Cryo-electron microscopy reveals the functional organization of an enveloped virus, Semliki Forest virus","volume":"5","author":"Mancini EJ","year":"2000","unstructured":"EJ Mancini, M Clarke, BE Gowen, T Rutten, SD Fuller, Cryo-electron microscopy reveals the functional organization of an enveloped virus, Semliki Forest virus. Mol Cell 5, 255\u2013266 (2000).","journal-title":"Mol Cell"},{"key":"e_1_3_4_12_2","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1016\/j.jmb.2011.09.045","article-title":"Molecular links between the E2 envelope glycoprotein and nucleocapsid core in Sindbis virus","volume":"414","author":"Tang J","year":"2011","unstructured":"J Tang, et al., Molecular links between the E2 envelope glycoprotein and nucleocapsid core in Sindbis virus. J Mol Biol 414, 442\u2013459 (2011).","journal-title":"J Mol Biol"},{"key":"e_1_3_4_13_2","doi-asserted-by":"crossref","first-page":"3854","DOI":"10.1038\/emboj.2011.261","article-title":"4.4 \u00c5 cryo-EM structure of an enveloped alphavirus Venezuelan equine encephalitis virus","volume":"30","author":"Zhang R","year":"2011","unstructured":"R Zhang, et al., 4.4 \u00c5 cryo-EM structure of an enveloped alphavirus Venezuelan equine encephalitis virus. EMBO J 30, 3854\u20133863 (2011).","journal-title":"EMBO J"},{"key":"e_1_3_4_14_2","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/S0092-8674(01)00302-6","article-title":"Locations of carbohydrate sites on alphavirus glycoproteins show that E1 forms an icosahedral scaffold","volume":"105","author":"Pletnev SV","year":"2001","unstructured":"SV Pletnev, et al., Locations of carbohydrate sites on alphavirus glycoproteins show that E1 forms an icosahedral scaffold. Cell 105, 127\u2013136 (2001).","journal-title":"Cell"},{"key":"e_1_3_4_15_2","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/S0092-8674(01)00303-8","article-title":"The Fusion glycoprotein shell of Semliki Forest virus: An icosahedral assembly primed for fusogenic activation at endosomal pH","volume":"105","author":"Lescar J","year":"2001","unstructured":"J Lescar, et al., The Fusion glycoprotein shell of Semliki Forest virus: An icosahedral assembly primed for fusogenic activation at endosomal pH. Cell 105, 137\u2013148 (2001).","journal-title":"Cell"},{"key":"e_1_3_4_16_2","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1038\/nature09546","article-title":"Structural changes of envelope proteins during alphavirus fusion","volume":"468","author":"Li L","year":"2010","unstructured":"L Li, J Jose, Y Xiang, RJ Kuhn, MG Rossmann, Structural changes of envelope proteins during alphavirus fusion. Nature 468, 705\u2013708 (2010).","journal-title":"Nature"},{"key":"e_1_3_4_17_2","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1038\/nature09555","article-title":"Glycoprotein organization of Chikungunya virus particles revealed by X-ray crystallography","volume":"468","author":"Voss JE","year":"2010","unstructured":"JE Voss, et al., Glycoprotein organization of Chikungunya virus particles revealed by X-ray crystallography. Nature 468, 709\u2013712 (2010).","journal-title":"Nature"},{"key":"e_1_3_4_18_2","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1038\/nature02239","article-title":"Conformational change and protein-protein interactions of the fusion protein of Semliki Forest virus","volume":"427","author":"Gibbons DL","year":"2004","unstructured":"DL Gibbons, et al., Conformational change and protein-protein interactions of the fusion protein of Semliki Forest virus. Nature 427, 320\u2013325 (2004).","journal-title":"Nature"},{"key":"e_1_3_4_19_2","doi-asserted-by":"crossref","first-page":"645","DOI":"10.1038\/468645a","article-title":"Structural biology: An alphavirus puzzle solved","volume":"468","author":"Kielian M","year":"2010","unstructured":"M Kielian, Structural biology: An alphavirus puzzle solved. Nature 468, 645\u2013646 (2010).","journal-title":"Nature"},{"key":"e_1_3_4_20_2","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1006\/viro.1998.9275","article-title":"The role of low pH and disulfide shuffling in the entry and fusion of Semliki Forest virus and Sindbis virus","volume":"248","author":"Glomb-Reinmund S","year":"1998","unstructured":"S Glomb-Reinmund, M Kielian, The role of low pH and disulfide shuffling in the entry and fusion of Semliki Forest virus and Sindbis virus. Virology 248, 372\u2013381 (1998).","journal-title":"Virology"},{"key":"e_1_3_4_21_2","unstructured":"JM Smit The role of N-linked glycosylation of Sindbis virus glycoproteins E2 and E1 in viral infectivity and membrane fusion activity. PhD thesis (Rijksuniversiteit Groningen). (2002)."},{"key":"e_1_3_4_22_2","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1016\/0092-8674(95)90533-2","article-title":"Low pH induces swiveling of the glycoprotein heterodimers in the Semliki Forest virus spike complex","volume":"81","author":"Fuller SD","year":"1995","unstructured":"SD Fuller, JA Berriman, SJ Butcher, BE Gowen, Low pH induces swiveling of the glycoprotein heterodimers in the Semliki Forest virus spike complex. Cell 81, 715\u2013725 (1995).","journal-title":"Cell"},{"key":"e_1_3_4_23_2","doi-asserted-by":"crossref","first-page":"4402","DOI":"10.1093\/emboj\/cdf442","article-title":"Acid-induced movements in the glycoprotein shell of an alphavirus turn the spikes into membrane fusion mode","volume":"21","author":"Haag L","year":"2002","unstructured":"L Haag, et al., Acid-induced movements in the glycoprotein shell of an alphavirus turn the spikes into membrane fusion mode. EMBO J 21, 4402\u20134410 (2002).","journal-title":"EMBO J"},{"key":"e_1_3_4_24_2","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1016\/j.virol.2004.03.046","article-title":"Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion","volume":"324","author":"Paredes AM","year":"2004","unstructured":"AM Paredes, et al., Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion. Virology 324, 373\u2013386 (2004).","journal-title":"Virology"},{"key":"e_1_3_4_25_2","doi-asserted-by":"crossref","first-page":"6752","DOI":"10.1074\/jbc.M609125200","article-title":"The dynamic envelope of a fusion class II virus. Prefusion stages of Semliki Forest virus revealed by electron cryomicroscopy","volume":"282","author":"Wu SR","year":"2007","unstructured":"SR Wu, et al., The dynamic envelope of a fusion class II virus. Prefusion stages of Semliki Forest virus revealed by electron cryomicroscopy. J Biol Chem 282, 6752\u20136762 (2007).","journal-title":"J Biol Chem"},{"key":"e_1_3_4_26_2","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1016\/j.jsb.2008.03.006","article-title":"Post-imaging fiducial markers aid in the orientation determination of complexes with mixed or unknown symmetry","volume":"162","author":"Bubeck D","year":"2008","unstructured":"D Bubeck, DJ Filman, M Kuzmin, SD Fuller, JM Hogle, Post-imaging fiducial markers aid in the orientation determination of complexes with mixed or unknown symmetry. J Struct Biol 162, 480\u2013490 (2008).","journal-title":"J Struct Biol"},{"key":"e_1_3_4_27_2","doi-asserted-by":"crossref","first-page":"11,645","DOI":"10.1128\/JVI.76.22.11645-11658.2002","article-title":"Placement of the structural proteins in Sindbis virus","volume":"76","author":"Zhang W","year":"2002","unstructured":"W Zhang, et al., Placement of the structural proteins in Sindbis virus. J Virol 76, 11,645\u201311,658 (2002).","journal-title":"J Virol"},{"key":"e_1_3_4_28_2","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1038\/nsmb955","article-title":"Cryo-electron microscopy reconstruction of a poliovirus-receptor-membrane complex","volume":"12","author":"Bubeck D","year":"2005","unstructured":"D Bubeck, DJ Filman, JM Hogle, Cryo-electron microscopy reconstruction of a poliovirus-receptor-membrane complex. Nat Struct Mol Biol 12, 615\u2013618 (2005).","journal-title":"Nat Struct Mol Biol"},{"key":"e_1_3_4_29_2","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1038\/nrm2272","article-title":"Vacuolar ATPases: Rotary proton pumps in physiology and pathophysiology","volume":"8","author":"Forgac M","year":"2007","unstructured":"M Forgac, Vacuolar ATPases: Rotary proton pumps in physiology and pathophysiology. Nat Rev Mol Cell Biol 8, 917\u2013929 (2007).","journal-title":"Nat Rev Mol Cell Biol"},{"key":"e_1_3_4_30_2","doi-asserted-by":"crossref","first-page":"1291","DOI":"10.1083\/jcb.108.4.1291","article-title":"Acidification of endosome subpopulations in wild-type Chinese hamster ovary cells and temperature-sensitive acidification-defective mutants","volume":"108","author":"Schmid S","year":"1989","unstructured":"S Schmid, R Fuchs, M Kielian, A Helenius, I Mellman, Acidification of endosome subpopulations in wild-type Chinese hamster ovary cells and temperature-sensitive acidification-defective mutants. J Cell Biol 108, 1291\u20131300 (1989).","journal-title":"J Cell Biol"},{"key":"e_1_3_4_31_2","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1146\/annurev.bi.55.070186.003311","article-title":"Acidification of the endocytic and exocytic pathways","volume":"55","author":"Mellman I","year":"1986","unstructured":"I Mellman, R Fuchs, A Helenius, Acidification of the endocytic and exocytic pathways. Annu Rev Biochem 55, 663\u2013700 (1986).","journal-title":"Annu Rev Biochem"},{"key":"e_1_3_4_32_2","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.str.2005.09.014","article-title":"Structure and interactions at the viral surface of the envelope protein E1 of Semliki Forest virus","volume":"14","author":"Roussel A","year":"2006","unstructured":"A Roussel, et al., Structure and interactions at the viral surface of the envelope protein E1 of Semliki Forest virus. Structure 14, 75\u201386 (2006).","journal-title":"Structure"},{"key":"e_1_3_4_33_2","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1006\/viro.1997.8799","article-title":"Membrane fusion activity of Semliki Forest virus in a liposomal model system: Specific inhibition by Zn2+ ions","volume":"238","author":"Corver J","year":"1997","unstructured":"J Corver, R Bron, H Snippe, C Kraaijeveld, J Wilschut, Membrane fusion activity of Semliki Forest virus in a liposomal model system: Specific inhibition by Zn2+ ions. Virology 238, 14\u201321 (1997).","journal-title":"Virology"},{"key":"e_1_3_4_34_2","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1083\/jcb.134.4.863","article-title":"Mechanisms of mutations inhibiting fusion and infection by Semliki Forest virus","volume":"134","author":"Kielian M","year":"1996","unstructured":"M Kielian, MR Klimjack, S Ghosh, WA Duffus, Mechanisms of mutations inhibiting fusion and infection by Semliki Forest virus. J Cell Biol 134, 863\u2013872 (1996).","journal-title":"J Cell Biol"},{"key":"e_1_3_4_35_2","doi-asserted-by":"crossref","first-page":"11,298","DOI":"10.1128\/JVI.01147-09","article-title":"E1 mutants identify a critical region in the trimer interface of the Semliki forest virus fusion protein","volume":"83","author":"Liu CY","year":"2009","unstructured":"CY Liu, M Kielian, E1 mutants identify a critical region in the trimer interface of the Semliki forest virus fusion protein. J Virol 83, 11,298\u201311,306 (2009).","journal-title":"J Virol"},{"key":"e_1_3_4_36_2","doi-asserted-by":"crossref","first-page":"7239","DOI":"10.1128\/JVI.76.14.7239-7246.2002","article-title":"Aura virus structure suggests that the T=4 organization is a fundamental property of viral structural proteins","volume":"76","author":"Zhang W","year":"2002","unstructured":"W Zhang, et al., Aura virus structure suggests that the T=4 organization is a fundamental property of viral structural proteins. J Virol 76, 7239\u20137246 (2002).","journal-title":"J Virol"},{"key":"e_1_3_4_37_2","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1006\/jsbi.1996.0020","article-title":"A model-based approach for determining orientations of biological macromolecules imaged by cryoelectron microscopy","volume":"116","author":"Baker TS","year":"1996","unstructured":"TS Baker, RH Cheng, A model-based approach for determining orientations of biological macromolecules imaged by cryoelectron microscopy. J Struct Biol 116, 120\u2013130 (1996).","journal-title":"J Struct Biol"},{"key":"e_1_3_4_38_2","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.jsb.2006.08.007","article-title":"AUTO3DEM\u2014An automated and high throughput program for image reconstruction of icosahedral particles","volume":"157","author":"Yan X","year":"2007","unstructured":"X Yan, RS Sinkovits, TS Baker, AUTO3DEM\u2014An automated and high throughput program for image reconstruction of icosahedral particles. J Struct Biol 157, 73\u201382 (2007).","journal-title":"J Struct Biol"},{"key":"e_1_3_4_39_2","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1006\/jsbi.1997.3896","article-title":"A method for establishing the handedness of biological macromolecules","volume":"120","author":"Belnap DM","year":"1997","unstructured":"DM Belnap, NH Olson, TS Baker, A method for establishing the handedness of biological macromolecules. J Struct Biol 120, 44\u201351 (1997).","journal-title":"J Struct Biol"},{"key":"e_1_3_4_40_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0022-2836(68)90050-8","article-title":"Structure of viruses of the papilloma-polyoma type. IV. Analysis of tilting experiments in the electron microscope","volume":"31","author":"Klug A","year":"1968","unstructured":"A Klug, JT Finch, Structure of viruses of the papilloma-polyoma type. IV. Analysis of tilting experiments in the electron microscope. J Mol Biol 31, 1\u201312 (1968).","journal-title":"J Mol Biol"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.1301911110","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,6,7]],"date-time":"2022-06-07T05:55:31Z","timestamp":1654581331000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.1301911110"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,7,29]]},"references-count":40,"journal-issue":{"issue":"33","published-print":{"date-parts":[[2013,8,13]]}},"alternative-id":["10.1073\/pnas.1301911110"],"URL":"https:\/\/doi.org\/10.1073\/pnas.1301911110","relation":{"has-review":[{"id-type":"doi","id":"10.3410\/f.718049944.793483821","asserted-by":"object"}]},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,7,29]]},"assertion":[{"value":"2013-07-29","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}