PMC:7108637 / 1909-5222
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7108637","sourcedb":"PMC","sourceid":"7108637","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7108637","text":"Enveloped viruses are well adapted pathogens infecting a great variety of hosts from protozoans to mammals that hijack the host cell’s molecular machinery for reproduction (International Committee on Taxonomy of Viruses 2012; Buchmann and Holmes 2015). They have evolved together with their hosts and developed various means to counteract the host’s defense mechanisms (Christiaansen et al. 2015; Beachboard and Horner 2016; Schuren et al. 2016). A characteristic feature of these viruses is a cell membrane-derived envelope modified with virally encoded proteins glycosylated by the host glycosylation apparatus as they pass through the secretory pathway. While some viral glycoproteins are glycosylated at relatively few sites, others are densely glycosylated with N-linked and O-linked glycans. Prominent examples include the Ebola virus glycoprotein modified by a very high content of O-linked glycans, and the HIV-1 glycoprotein gp160 that is glycosylated by the addition of multiple N-linked glycans (Jeffers et al. 2002; Pabst et al. 2012; Yang W et al. 2014). Although specific functional roles have been assigned to distinct glycosites of multiple viruses (Goffard et al. 2005; Falkowska et al. 2007; Helle et al. 2010; Wang et al. 2013, 2017; Lennemann et al. 2014; Bradel-Tretheway et al. 2015; Luo et al. 2015; Orlova et al. 2015; Suenaga et al. 2015; Stone et al. 2016; Wu et al. 2017), it is generally believed that the high levels of glycosylation serve as a protective shield from the host’s immune system (Francica et al. 2010; Helle et al. 2011; Sommerstein et al. 2015; Behrens et al. 2016; Gram et al. 2016; Walls et al. 2016). The other major role of glycosylation occurs during virus entry where glycans on the host cell represent viral receptors interacting with carbohydrate binding proteins on the viral surface. A prominent example is the influenza viruses that attach to surface glycans residing on cellular glycoproteins (Air 2014). Hemagglutinins (HA) of human influenza viruses use α2,6-linked sialic acid moieties, while those of avian viruses bind preferentially to α2,3-linked sialic acids (Air 2014). Apart from influenza virus, several other nonenveloped human viruses, including adenoviruses, reoviruses and rotaviruses, use sialic acid-containing oligosaccharides as cell receptors (Stencel-Baerenwald et al. 2014). Sialic acid is not the only glycan that can be used by viruses for cell attachment. For example, flaviviruses, human respiratory syncytial virus and some of the herpesviruses use proteoglycans as a point of attachment to cells, whereas core fucosylation is suggested to play a role in HBV entry into hepatoma cells (Jolly and Sattentau 2013; Takamatsu et al. 2016). The important aspects of host glycans as receptors for viral infectivity will not be reviewed here as they are covered elsewhere (Jolly and Sattentau 2013; Stencel-Baerenwald et al. 2014; Kim et al. 2017). Instead, we will present the available information on glycosylation of human enveloped viruses. We will discuss general functions of glycosylation in various aspects of the viral life cycle and interaction with the immune system. In addition, we will discuss human herpesvirus glycosylation in more detail and include conclusions emerging from our recent global O-glycoproteomic analyses.","tracks":[{"project":"2_test","denotations":[{"id":"29579213-26378223-45167182","span":{"begin":246,"end":250},"obj":"26378223"},{"id":"29579213-26177523-45167183","span":{"begin":391,"end":395},"obj":"26177523"},{"id":"29579213-27288760-45167184","span":{"begin":419,"end":423},"obj":"27288760"},{"id":"29579213-27065088-45167185","span":{"begin":440,"end":444},"obj":"27065088"},{"id":"29579213-12438572-45167186","span":{"begin":1022,"end":1026},"obj":"12438572"},{"id":"29579213-22944675-45167187","span":{"begin":1041,"end":1045},"obj":"22944675"},{"id":"29579213-24941220-45167188","span":{"begin":1061,"end":1065},"obj":"24941220"},{"id":"29579213-15956584-45167189","span":{"begin":1181,"end":1185},"obj":"15956584"},{"id":"29579213-17507469-45167190","span":{"begin":1204,"end":1208},"obj":"17507469"},{"id":"29579213-20844034-45167191","span":{"begin":1223,"end":1227},"obj":"20844034"},{"id":"29579213-23384254-45167192","span":{"begin":1241,"end":1245},"obj":"23384254"},{"id":"29579213-28196864-45167193","span":{"begin":1247,"end":1251},"obj":"28196864"},{"id":"29579213-24473128-45167194","span":{"begin":1270,"end":1274},"obj":"24473128"},{"id":"29579213-25948743-45167195","span":{"begin":1300,"end":1304},"obj":"25948743"},{"id":"29579213-25965797-45167196","span":{"begin":1317,"end":1321},"obj":"25965797"},{"id":"29579213-26105052-45167197","span":{"begin":1358,"end":1362},"obj":"26105052"},{"id":"29579213-26867212-45167198","span":{"begin":1377,"end":1381},"obj":"26867212"},{"id":"29579213-28028222-45167199","span":{"begin":1393,"end":1397},"obj":"28028222"},{"id":"29579213-20844579-45167200","span":{"begin":1539,"end":1543},"obj":"20844579"},{"id":"29579213-22069522-45167201","span":{"begin":1558,"end":1562},"obj":"22069522"},{"id":"29579213-26587982-45167202","span":{"begin":1583,"end":1587},"obj":"26587982"},{"id":"29579213-26972002-45167203","span":{"begin":1604,"end":1608},"obj":"26972002"},{"id":"29579213-27077376-45167204","span":{"begin":1622,"end":1626},"obj":"27077376"},{"id":"29579213-27617430-45167205","span":{"begin":1641,"end":1645},"obj":"27617430"},{"id":"29579213-25061947-45167206","span":{"begin":1954,"end":1958},"obj":"25061947"},{"id":"29579213-25061947-45167207","span":{"begin":2128,"end":2132},"obj":"25061947"},{"id":"29579213-25263223-45167208","span":{"begin":2346,"end":2350},"obj":"25263223"},{"id":"29579213-23884583-45167209","span":{"begin":2689,"end":2693},"obj":"23884583"},{"id":"29579213-27329181-45167210","span":{"begin":2712,"end":2716},"obj":"27329181"},{"id":"29579213-23884583-45167211","span":{"begin":2869,"end":2873},"obj":"23884583"},{"id":"29579213-25263223-45167212","span":{"begin":2901,"end":2905},"obj":"25263223"},{"id":"29579213-28471403-45167213","span":{"begin":2918,"end":2922},"obj":"28471403"},{"id":"T46268","span":{"begin":246,"end":250},"obj":"26378223"},{"id":"T62997","span":{"begin":391,"end":395},"obj":"26177523"},{"id":"T31998","span":{"begin":419,"end":423},"obj":"27288760"},{"id":"T98541","span":{"begin":440,"end":444},"obj":"27065088"},{"id":"T8616","span":{"begin":1022,"end":1026},"obj":"12438572"},{"id":"T43868","span":{"begin":1041,"end":1045},"obj":"22944675"},{"id":"T30234","span":{"begin":1061,"end":1065},"obj":"24941220"},{"id":"T42961","span":{"begin":1181,"end":1185},"obj":"15956584"},{"id":"T93833","span":{"begin":1204,"end":1208},"obj":"17507469"},{"id":"T90648","span":{"begin":1223,"end":1227},"obj":"20844034"},{"id":"T74168","span":{"begin":1241,"end":1245},"obj":"23384254"},{"id":"T20466","span":{"begin":1247,"end":1251},"obj":"28196864"},{"id":"T4727","span":{"begin":1270,"end":1274},"obj":"24473128"},{"id":"T8249","span":{"begin":1300,"end":1304},"obj":"25948743"},{"id":"T68140","span":{"begin":1317,"end":1321},"obj":"25965797"},{"id":"T82537","span":{"begin":1358,"end":1362},"obj":"26105052"},{"id":"T799","span":{"begin":1377,"end":1381},"obj":"26867212"},{"id":"T51237","span":{"begin":1393,"end":1397},"obj":"28028222"},{"id":"T64080","span":{"begin":1539,"end":1543},"obj":"20844579"},{"id":"T66205","span":{"begin":1558,"end":1562},"obj":"22069522"},{"id":"T44563","span":{"begin":1583,"end":1587},"obj":"26587982"},{"id":"T88112","span":{"begin":1604,"end":1608},"obj":"26972002"},{"id":"T13877","span":{"begin":1622,"end":1626},"obj":"27077376"},{"id":"T43424","span":{"begin":1641,"end":1645},"obj":"27617430"},{"id":"T50012","span":{"begin":1954,"end":1958},"obj":"25061947"},{"id":"T13200","span":{"begin":2128,"end":2132},"obj":"25061947"},{"id":"T24965","span":{"begin":2346,"end":2350},"obj":"25263223"},{"id":"T18823","span":{"begin":2689,"end":2693},"obj":"23884583"},{"id":"T10987","span":{"begin":2712,"end":2716},"obj":"27329181"},{"id":"T89784","span":{"begin":2869,"end":2873},"obj":"23884583"},{"id":"T4243","span":{"begin":2901,"end":2905},"obj":"25263223"},{"id":"T17589","span":{"begin":2918,"end":2922},"obj":"28471403"}],"attributes":[{"subj":"29579213-26378223-45167182","pred":"source","obj":"2_test"},{"subj":"29579213-26177523-45167183","pred":"source","obj":"2_test"},{"subj":"29579213-27288760-45167184","pred":"source","obj":"2_test"},{"subj":"29579213-27065088-45167185","pred":"source","obj":"2_test"},{"subj":"29579213-12438572-45167186","pred":"source","obj":"2_test"},{"subj":"29579213-22944675-45167187","pred":"source","obj":"2_test"},{"subj":"29579213-24941220-45167188","pred":"source","obj":"2_test"},{"subj":"29579213-15956584-45167189","pred":"source","obj":"2_test"},{"subj":"29579213-17507469-45167190","pred":"source","obj":"2_test"},{"subj":"29579213-20844034-45167191","pred":"source","obj":"2_test"},{"subj":"29579213-23384254-45167192","pred":"source","obj":"2_test"},{"subj":"29579213-28196864-45167193","pred":"source","obj":"2_test"},{"subj":"29579213-24473128-45167194","pred":"source","obj":"2_test"},{"subj":"29579213-25948743-45167195","pred":"source","obj":"2_test"},{"subj":"29579213-25965797-45167196","pred":"source","obj":"2_test"},{"subj":"29579213-26105052-45167197","pred":"source","obj":"2_test"},{"subj":"29579213-26867212-45167198","pred":"source","obj":"2_test"},{"subj":"29579213-28028222-45167199","pred":"source","obj":"2_test"},{"subj":"29579213-20844579-45167200","pred":"source","obj":"2_test"},{"subj":"29579213-22069522-45167201","pred":"source","obj":"2_test"},{"subj":"29579213-26587982-45167202","pred":"source","obj":"2_test"},{"subj":"29579213-26972002-45167203","pred":"source","obj":"2_test"},{"subj":"29579213-27077376-45167204","pred":"source","obj":"2_test"},{"subj":"29579213-27617430-45167205","pred":"source","obj":"2_test"},{"subj":"29579213-25061947-45167206","pred":"source","obj":"2_test"},{"subj":"29579213-25061947-45167207","pred":"source","obj":"2_test"},{"subj":"29579213-25263223-45167208","pred":"source","obj":"2_test"},{"subj":"29579213-23884583-45167209","pred":"source","obj":"2_test"},{"subj":"29579213-27329181-45167210","pred":"source","obj":"2_test"},{"subj":"29579213-23884583-45167211","pred":"source","obj":"2_test"},{"subj":"29579213-25263223-45167212","pred":"source","obj":"2_test"},{"subj":"29579213-28471403-45167213","pred":"source","obj":"2_test"},{"subj":"T46268","pred":"source","obj":"2_test"},{"subj":"T62997","pred":"source","obj":"2_test"},{"subj":"T31998","pred":"source","obj":"2_test"},{"subj":"T98541","pred":"source","obj":"2_test"},{"subj":"T8616","pred":"source","obj":"2_test"},{"subj":"T43868","pred":"source","obj":"2_test"},{"subj":"T30234","pred":"source","obj":"2_test"},{"subj":"T42961","pred":"source","obj":"2_test"},{"subj":"T93833","pred":"source","obj":"2_test"},{"subj":"T90648","pred":"source","obj":"2_test"},{"subj":"T74168","pred":"source","obj":"2_test"},{"subj":"T20466","pred":"source","obj":"2_test"},{"subj":"T4727","pred":"source","obj":"2_test"},{"subj":"T8249","pred":"source","obj":"2_test"},{"subj":"T68140","pred":"source","obj":"2_test"},{"subj":"T82537","pred":"source","obj":"2_test"},{"subj":"T799","pred":"source","obj":"2_test"},{"subj":"T51237","pred":"source","obj":"2_test"},{"subj":"T64080","pred":"source","obj":"2_test"},{"subj":"T66205","pred":"source","obj":"2_test"},{"subj":"T44563","pred":"source","obj":"2_test"},{"subj":"T88112","pred":"source","obj":"2_test"},{"subj":"T13877","pred":"source","obj":"2_test"},{"subj":"T43424","pred":"source","obj":"2_test"},{"subj":"T50012","pred":"source","obj":"2_test"},{"subj":"T13200","pred":"source","obj":"2_test"},{"subj":"T24965","pred":"source","obj":"2_test"},{"subj":"T18823","pred":"source","obj":"2_test"},{"subj":"T10987","pred":"source","obj":"2_test"},{"subj":"T89784","pred":"source","obj":"2_test"},{"subj":"T4243","pred":"source","obj":"2_test"},{"subj":"T17589","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ecc093","default":true}]}]}}