Human Immunodeficiency Virus and Simian Immunodeficiency Virus Maintain High Levels of Infectivity in the Complete Absence of Mucin-Type O-Glycosylation
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
A highly conserved threonine near the C terminus of gp120 of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) was investigated for its contributions to envelope protein function and virion infectivity. When this highly conserved Thr residue was substituted with anything other than serine (the other amino acid that can accept O-glycosylation), the resulting virus was noninfectious. We found that this Thr was critical for the association of gp120 with the virion and that amino acid substitution increased the amount of dissociated gp120 in the cell culture supernatant. When HIV virions were generated in cells overexpressing polypeptide N-acetylgalactosaminyltransferase 1 (GalNAcT1), viral infectivity was increased 2.5-fold compared to that of virus produced in wild-type HEK293T cells; infectivity was increased 8-fold when the Thr499Ser mutant was used. These infectivity enhancements were not observed when GalNAcT3 was used. Using HEK293T knockout cell lines totally devoid of the ability to perform O-linked glycosylation, we demonstrated production of normal levels of virions and normal levels of infectivity in the complete absence of O-linked carbohydrate. Our data indicate that O-glycosylation is not necessary for the natural replication cycle of HIV and SIV. Nonetheless, it remains theoretically possible that the repertoire of GalNAc transferase isoforms in natural target cells for HIV and SIV in vivo could result in O-glycosylation of the threonine residue in question and that this could boost the infectivity of virions beyond the levels seen in the absence of such O-glycosylation.
Date Issued
2017-07-26
Date Acceptance
2017-07-18
Citation
JOURNAL OF VIROLOGY, 2017, 91 (19)
ISSN
0022-538X
Publisher
American Society for Microbiology
Journal / Book Title
JOURNAL OF VIROLOGY
Volume
91
Issue
19
Copyright Statement
© 2017 American Society for Microbiology.
Sponsor
Biotechnology and Biological Sciences Research Council (BBSRC)
Wellcome Trust
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000410261600040&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
BB/K016164/1
102978/Z/13/Z
Subjects
Science & Technology
Life Sciences & Biomedicine
Virology
envelope
glycosylation
infectivity
O-linked glycosylation
gp120
human immunodeficiency virus
simian immunodeficiency virus
HIV-1 ENVELOPE
NEUTRALIZING ANTIBODIES
VIRAL ENTRY
SOLUBLE CD4
N-GLYCANS
GP120
GP41
CARBOHYDRATE
GLYCOPROTEIN
CELL
Amino Acid Substitution
Cell Line
Galactokinase
Gene Knockout Techniques
Glycosylation
HEK293 Cells
HIV
HIV Envelope Protein gp120
HIV Infections
Humans
Mucins
N-Acetylgalactosaminyltransferases
Simian Immunodeficiency Virus
Viral Envelope Proteins
Simian immunodeficiency virus
06 Biological Sciences
07 Agricultural And Veterinary Sciences
11 Medical And Health Sciences
Publication Status
Published
Article Number
UNSP e01228-17