Previous Article | Next Article ![]()
Journal of Virology, October 1998, p. 8365-8370, Vol. 72, No. 10
Department of Viral
Infection1 and
Department of Infectious
Diseases,
Received 20 April 1998/Accepted 23 June 1998
One of the striking features of human immunodeficiency virus,
simian immunodeficiency virus (SIV), and other lentiviruses is
extensive N glycosylation of the envelope protein. To assess the
requirement of each N glycan for viral infectivity, we individually silenced all 23 N glycosylation sites in the gp120 subunit of SIVmac239
envelope protein by mutagenizing the canonical Asn-Xaa-Thr/Ser N
glycosylation motif in an infectious molecular clone, attempted to
rescue viruses from the clones, and compared the replication capability
of the rescued viruses in MT4 cells. The mutation resulted in either
the recovery of a fully infectious virus (category I); recovery of a
faster-replicating virus, compared with the parental virus (category
II); or no virus recovery (category III). These categorically different
sites were not distributed randomly but were clustered. The sites of
category I were localized largely in the N-terminal half, whereas the
sites of categories II and III were localized in the C-terminal region,
including the CD4 binding site, and the central part, including the C
loop, respectively. To learn how far SIV can tolerate the removal of
glycans, multiplex mutagenesis was also attempted. When they were
appreciably distant from one another in the primary sequence, up to
five sites could be silenced in combination without disturbing
infectivity. On the other hand, it was difficult to silence contiguous
sites. Thus, it appeared that a certain degree of sugar chain density over the local region had to be preserved. We discuss the potential utility of these variously deglycosylated mutants for clarifying the
role of N glycans in SIV replication in vivo, as well as in the host
response, and for designing vaccines and the generation of glycoprotein
crystals.
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Location-Specific, Unequal Contribution of the N Glycans in
Simian Immunodeficiency Virus gp120 to Viral Infectivity and
Removal of Multiple Glycans without Disturbing
Infectivity
*
Corresponding author. Mailing address: Department of
Viral Infection, Institute of Medical Science, University of Tokyo,
4-6-1 Shiroganedai, Minato-ku, Tokyo 108, Japan. Phone: 81-3-5449-5285. Fax: 81-3-5449-5409. E-mail:
ynagai{at}ims.u-tokyo.ac.jp.
Journal of Virology, October 1998, p. 8365-8370, Vol. 72, No. 10
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|