The signal peptide of the ebolavirus glycoprotein influences interaction with the cellular lectins DC-SIGN and DC-SIGNR.
The C-type lectins DC-SIGN and DC-SIGNR (collectively referred to as DC-SIGN/R) bind to the ebolavirus glycoprotein (EBOV-GP) and augment viral infectivity. DC-SIGN/R strongly enhance infection driven by the GP of EBOV subspecies. Zaire (ZEBOV) but have a much less pronounced effect on infection mediated by the GP of EBOV subspecies. Sudan (SEBOV). For this study, we analyzed the determinants of the differential DC-SIGN/R interactions with ZEBOV- and SEBOV-GP. The efficiency of DC-SIGN engagement by ZEBOV-GP was dependent on the rate of GP incorporation into lentiviral particles, while appreciable virion incorporation of SEBOV-GP did not allow robust DC-SIGN/R usage. Forced incorporation of high-mannose carbohydrates into SEBOV-GP augmented the engagement of DC-SIGN/R to the levels observed with ZEBOV-GP, indicating that appropriate glycosylation of SEBOV-GP is sufficient for efficient DC-SIGN/R usage. However, neither signals for N-linked glycosylation unique to SEBOV- or ZEBOV-GP nor the highly variable and heavily glycosylated mucin-like domain modulated the interaction with DC-SIGN/R. In contrast, analysis of chimeric GPs identified the signal peptide as a determinant of DC-SIGN/R engagement. Thus, ZEBOV- but not SEBOV-GP was shown to harbor high-mannose carbohydrates, and GP modification with these glycans was controlled by the signal peptide. These results suggest that the signal peptide governs EBOV-GP interactions with DC-SIGN/R by modulating the incorporation of high-mannose carbohydrates into EBOV-GP. In summary, we identified the level of GP incorporation into virions and signal peptide-controlled glycosylation of GP as determinants of attachment factor engagement.
Marzi
Andrea
A
Institute for Clinical and Molecular Virology and Nikolaus-Fiebiger-Center, University Erlangen-Nürnberg, Glückstrasse 6, 91054 Erlangen, Germany.
Akhavan
Armin
A
Simmons
Graham
G
Gramberg
Thomas
T
Hofmann
Heike
H
Bates
Paul
P
Lingappa
Vishwanath R
VR
Pöhlmann
Stefan
S
D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D029043:Ebolavirus / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D019142:Hemorrhagic Fever, Ebola / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D037181:Lectins, C-Type / Q000378:metabolism*; D016086:Lentivirus; D008358:Mannose / Q000378:metabolism; D009077:Mucins / Q000235:genetics / Q000378:metabolism; D050506:Mutant Chimeric Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D046188:Protein Modification, Translational / Q000502:physiology*; D021382:Protein Sorting Signals / Q000502:physiology*; D017434:Protein Structure, Tertiary / Q000502:physiology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000235:genetics / Q000378:metabolism; D019065:Virus Assembly / Q000502:physiology; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
D015815:Cell Adhesion Molecules; D037181:Lectins, C-Type; D008358:Mannose; D009077:Mucins; D050506:Mutant Chimeric Proteins; D021382:Protein Sorting Signals; D011956:Receptors, Cell Surface; D014759:Viral Envelope Proteins; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C433029:CLEC4M protein, human; C113189:envelope glycoprotein, Ebola virus