PMC:7100515 / 20165-22219 JSON TXT

Annnotations TAB JSON ListView MergeView

LitCovid-PD-FMA-UBERON

LitCovid_AGAC

{"project":"LitCovid_AGAC","denotations":[{"id":"p44067s7","span":{"begin":65,"end":73},"obj":"PosReg"},{"id":"p44067s23","span":{"begin":141,"end":181},"obj":"MPA"},{"id":"p44069s19","span":{"begin":486,"end":494},"obj":"PosReg"},{"id":"p44069s20","span":{"begin":492,"end":542},"obj":"MPA"},{"id":"p44078s8","span":{"begin":1438,"end":1447},"obj":"NegReg"},{"id":"p44078s10","span":{"begin":1452,"end":1473},"obj":"MPA"},{"id":"p44078s15","span":{"begin":1485,"end":1494},"obj":"PosReg"},{"id":"p44078s16","span":{"begin":1495,"end":1512},"obj":"MPA"}],"text":"Type II membrane serine proteases (TMPRSS)-mediated cleavage can activate the fusion potential of SARS-CoV and MERS-CoV S protein and induce receptor-dependent syncytium formation28,29,38,39. To test whether SARS-CoV-2 S protein cleaved by these cellular proteases could trigger syncytium formation, we overlaid HEK 293T cells expressing SARS-CoV-2 S or control proteins on 293/hACE2 cells in presence or absence of proteases. Expression of TMPRSS 2, 4, 11 A, 11D, and 11E on 293/hACE2 cells enhanced SARS-CoV-2 S protein-mediated cell–cell fusion similarly to SASR-CoV S (Supplementary Fig. 2). Next we evaluated the role of trypsin. Consistent to our previous report23, addition of trypsin triggered syncytium formation on 293/hACE2 cells by SARS-CoV S protein after 4 h incubation (Fig. 4b, c). Large syncytia were formed at a level similar to SARS-CoV S proteins when SARS-CoV-2 S protein expressing 293T cells were added onto 293/hACE2 cells with trypsin. Of note, SARS-CoV-2, but not SARS-CoV, S proteins induced syncytia formation on 293/hACE2 cells even in the absence of trypsin (Fig. 4c), suggesting that SARS-CoV-2 S proteins could be triggered upon the receptor binding without exogenous protease priming or activation. During 2013–2016 Ebola virus outbreak, A82V and T544I mutations in glycoprotein (gp) of Ebola virus were linked to increase of virus transmissibility40–42. Further study showed that A82V and T544I mutation decreases the thermostability of gp while they increases virus infectivity in cell culture42. We then investigated the thermostability of SARS-CoV-2 S protein. Compared to SARS-CoV S protein, SARS-CoV-2 S protein was less stable, requiring significant shorter time and lower temperature to be inactivated (Fig. 4d, e). The native S protein is metastable, and there is an energy barrier that prevents it from undergoing conformational change before triggering, SARS-CoV-2 S protein might decrease its energy barrier by reducing its thermostability. This might contribute to high-transmission efficiency of SARS-CoV-2."}

LitCovid-PD-MONDO

LitCovid-PD-CLO

LitCovid-PD-CHEBI

LitCovid-PD-GO-BP

{"project":"LitCovid-PD-GO-BP","denotations":[{"id":"T36","span":{"begin":279,"end":298},"obj":"http://purl.obolibrary.org/obo/GO_0006949"},{"id":"T37","span":{"begin":289,"end":298},"obj":"http://purl.obolibrary.org/obo/GO_0009058"},{"id":"T38","span":{"begin":536,"end":547},"obj":"http://purl.obolibrary.org/obo/GO_0140253"},{"id":"T39","span":{"begin":536,"end":547},"obj":"http://purl.obolibrary.org/obo/GO_0045026"},{"id":"T40","span":{"begin":536,"end":547},"obj":"http://purl.obolibrary.org/obo/GO_0000768"},{"id":"T41","span":{"begin":536,"end":547},"obj":"http://purl.obolibrary.org/obo/GO_0000747"},{"id":"T42","span":{"begin":702,"end":721},"obj":"http://purl.obolibrary.org/obo/GO_0006949"},{"id":"T43","span":{"begin":712,"end":721},"obj":"http://purl.obolibrary.org/obo/GO_0009058"},{"id":"T44","span":{"begin":1028,"end":1037},"obj":"http://purl.obolibrary.org/obo/GO_0009058"}],"text":"Type II membrane serine proteases (TMPRSS)-mediated cleavage can activate the fusion potential of SARS-CoV and MERS-CoV S protein and induce receptor-dependent syncytium formation28,29,38,39. To test whether SARS-CoV-2 S protein cleaved by these cellular proteases could trigger syncytium formation, we overlaid HEK 293T cells expressing SARS-CoV-2 S or control proteins on 293/hACE2 cells in presence or absence of proteases. Expression of TMPRSS 2, 4, 11 A, 11D, and 11E on 293/hACE2 cells enhanced SARS-CoV-2 S protein-mediated cell–cell fusion similarly to SASR-CoV S (Supplementary Fig. 2). Next we evaluated the role of trypsin. Consistent to our previous report23, addition of trypsin triggered syncytium formation on 293/hACE2 cells by SARS-CoV S protein after 4 h incubation (Fig. 4b, c). Large syncytia were formed at a level similar to SARS-CoV S proteins when SARS-CoV-2 S protein expressing 293T cells were added onto 293/hACE2 cells with trypsin. Of note, SARS-CoV-2, but not SARS-CoV, S proteins induced syncytia formation on 293/hACE2 cells even in the absence of trypsin (Fig. 4c), suggesting that SARS-CoV-2 S proteins could be triggered upon the receptor binding without exogenous protease priming or activation. During 2013–2016 Ebola virus outbreak, A82V and T544I mutations in glycoprotein (gp) of Ebola virus were linked to increase of virus transmissibility40–42. Further study showed that A82V and T544I mutation decreases the thermostability of gp while they increases virus infectivity in cell culture42. We then investigated the thermostability of SARS-CoV-2 S protein. Compared to SARS-CoV S protein, SARS-CoV-2 S protein was less stable, requiring significant shorter time and lower temperature to be inactivated (Fig. 4d, e). The native S protein is metastable, and there is an energy barrier that prevents it from undergoing conformational change before triggering, SARS-CoV-2 S protein might decrease its energy barrier by reducing its thermostability. This might contribute to high-transmission efficiency of SARS-CoV-2."}

LitCovid-sentences

{"project":"LitCovid-sentences","denotations":[{"id":"T149","span":{"begin":0,"end":191},"obj":"Sentence"},{"id":"T150","span":{"begin":192,"end":426},"obj":"Sentence"},{"id":"T151","span":{"begin":427,"end":595},"obj":"Sentence"},{"id":"T152","span":{"begin":596,"end":634},"obj":"Sentence"},{"id":"T153","span":{"begin":635,"end":797},"obj":"Sentence"},{"id":"T154","span":{"begin":798,"end":960},"obj":"Sentence"},{"id":"T155","span":{"begin":961,"end":1231},"obj":"Sentence"},{"id":"T156","span":{"begin":1232,"end":1387},"obj":"Sentence"},{"id":"T157","span":{"begin":1388,"end":1531},"obj":"Sentence"},{"id":"T158","span":{"begin":1532,"end":1597},"obj":"Sentence"},{"id":"T159","span":{"begin":1598,"end":1756},"obj":"Sentence"},{"id":"T160","span":{"begin":1757,"end":1985},"obj":"Sentence"},{"id":"T161","span":{"begin":1986,"end":2054},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Type II membrane serine proteases (TMPRSS)-mediated cleavage can activate the fusion potential of SARS-CoV and MERS-CoV S protein and induce receptor-dependent syncytium formation28,29,38,39. To test whether SARS-CoV-2 S protein cleaved by these cellular proteases could trigger syncytium formation, we overlaid HEK 293T cells expressing SARS-CoV-2 S or control proteins on 293/hACE2 cells in presence or absence of proteases. Expression of TMPRSS 2, 4, 11 A, 11D, and 11E on 293/hACE2 cells enhanced SARS-CoV-2 S protein-mediated cell–cell fusion similarly to SASR-CoV S (Supplementary Fig. 2). Next we evaluated the role of trypsin. Consistent to our previous report23, addition of trypsin triggered syncytium formation on 293/hACE2 cells by SARS-CoV S protein after 4 h incubation (Fig. 4b, c). Large syncytia were formed at a level similar to SARS-CoV S proteins when SARS-CoV-2 S protein expressing 293T cells were added onto 293/hACE2 cells with trypsin. Of note, SARS-CoV-2, but not SARS-CoV, S proteins induced syncytia formation on 293/hACE2 cells even in the absence of trypsin (Fig. 4c), suggesting that SARS-CoV-2 S proteins could be triggered upon the receptor binding without exogenous protease priming or activation. During 2013–2016 Ebola virus outbreak, A82V and T544I mutations in glycoprotein (gp) of Ebola virus were linked to increase of virus transmissibility40–42. Further study showed that A82V and T544I mutation decreases the thermostability of gp while they increases virus infectivity in cell culture42. We then investigated the thermostability of SARS-CoV-2 S protein. Compared to SARS-CoV S protein, SARS-CoV-2 S protein was less stable, requiring significant shorter time and lower temperature to be inactivated (Fig. 4d, e). The native S protein is metastable, and there is an energy barrier that prevents it from undergoing conformational change before triggering, SARS-CoV-2 S protein might decrease its energy barrier by reducing its thermostability. This might contribute to high-transmission efficiency of SARS-CoV-2."}

2_test

{"project":"2_test","denotations":[{"id":"32221306-23468491-73894029","span":{"begin":179,"end":181},"obj":"23468491"},{"id":"32221306-24098509-73894030","span":{"begin":182,"end":184},"obj":"24098509"},{"id":"32221306-21325420-73894031","span":{"begin":185,"end":187},"obj":"21325420"},{"id":"32221306-20926566-73894032","span":{"begin":188,"end":190},"obj":"20926566"},{"id":"32221306-27030273-73894033","span":{"begin":668,"end":670},"obj":"27030273"},{"id":"32221306-27814506-73894034","span":{"begin":1381,"end":1383},"obj":"27814506"},{"id":"32221306-27814505-73894034","span":{"begin":1381,"end":1383},"obj":"27814505"},{"id":"32221306-28238624-73894034","span":{"begin":1381,"end":1383},"obj":"28238624"},{"id":"32221306-28238624-73894035","span":{"begin":1528,"end":1530},"obj":"28238624"}],"text":"Type II membrane serine proteases (TMPRSS)-mediated cleavage can activate the fusion potential of SARS-CoV and MERS-CoV S protein and induce receptor-dependent syncytium formation28,29,38,39. To test whether SARS-CoV-2 S protein cleaved by these cellular proteases could trigger syncytium formation, we overlaid HEK 293T cells expressing SARS-CoV-2 S or control proteins on 293/hACE2 cells in presence or absence of proteases. Expression of TMPRSS 2, 4, 11 A, 11D, and 11E on 293/hACE2 cells enhanced SARS-CoV-2 S protein-mediated cell–cell fusion similarly to SASR-CoV S (Supplementary Fig. 2). Next we evaluated the role of trypsin. Consistent to our previous report23, addition of trypsin triggered syncytium formation on 293/hACE2 cells by SARS-CoV S protein after 4 h incubation (Fig. 4b, c). Large syncytia were formed at a level similar to SARS-CoV S proteins when SARS-CoV-2 S protein expressing 293T cells were added onto 293/hACE2 cells with trypsin. Of note, SARS-CoV-2, but not SARS-CoV, S proteins induced syncytia formation on 293/hACE2 cells even in the absence of trypsin (Fig. 4c), suggesting that SARS-CoV-2 S proteins could be triggered upon the receptor binding without exogenous protease priming or activation. During 2013–2016 Ebola virus outbreak, A82V and T544I mutations in glycoprotein (gp) of Ebola virus were linked to increase of virus transmissibility40–42. Further study showed that A82V and T544I mutation decreases the thermostability of gp while they increases virus infectivity in cell culture42. We then investigated the thermostability of SARS-CoV-2 S protein. Compared to SARS-CoV S protein, SARS-CoV-2 S protein was less stable, requiring significant shorter time and lower temperature to be inactivated (Fig. 4d, e). The native S protein is metastable, and there is an energy barrier that prevents it from undergoing conformational change before triggering, SARS-CoV-2 S protein might decrease its energy barrier by reducing its thermostability. This might contribute to high-transmission efficiency of SARS-CoV-2."}

LitCovid-PubTator

PMC:7100515 / 20165-22219 JSONTXT

Annnotations TAB JSON ListView MergeView

PMC:7100515 / 20165-22219 JSON TXT