Gag-Pol Transframe Domain p6 Is Essential for HIV-1 Protease-Mediated Virus Maturation
HIV-1 protease (PR) is encoded by pol, which is initially translated as a Pr160gag-pol polyprotein by a ribosomal frameshift event. Within Gag-Pol, truncated p6gag is replaced by a transframe domain (referred to as p6* or p6pol) located directly upstream of PR. p6* has been proposed as playing a rol...
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Published in | PloS one Vol. 10; no. 6; p. e0127974 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Public Library of Science
01.06.2015
Public Library of Science (PLoS) |
Subjects | |
Online Access | Get full text |
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Summary: | HIV-1 protease (PR) is encoded by pol, which is initially translated as a Pr160gag-pol polyprotein by a ribosomal frameshift event. Within Gag-Pol, truncated p6gag is replaced by a transframe domain (referred to as p6* or p6pol) located directly upstream of PR. p6* has been proposed as playing a role in modulating PR activation. Overlapping reading frames between p6* and p6gag present a challenge to researchers using genetic approaches to studying p6* biological functions. To determine the role of p6* in PR activation without affecting the gag reading frame, we constructed a series of Gag/Gag-Pol expression vectors by duplicating PR with or without p6* between PR pairs, and observed that PR duplication eliminated virus production due to significant Gag cleavage enhancement. This effect was mitigated when p6* was placed between the two PRs. Further, Gag cleavage enhancement was markedly reduced when either one of the two PRs was mutationally inactivated. Additional reduction in Gag cleavage efficiency was noted following the removal of p6* from between the two PRs. The insertion of a NC domain (wild-type or mutant) directly upstream of PR or p6*PR did not significantly improve Gag processing efficiency. With the exception of those containing p6* directly upstream of an active PR, all constructs were either noninfectious or weakly infectious. Our results suggest that (a) p6* is essential for triggering PR activation, (b) p6* has a role in preventing premature virus processing, and |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Current address: Department of Physical Medicine & Rehabilitation, National Taiwan University College of Medicine, Taipei, Taiwan Competing Interests: The authors have declared that no competing interests exist. Conceived and designed the experiments: FHY CTW. Performed the experiments: FHY TAC. Analyzed the data: TAC CTW. Contributed reagents/materials/analysis tools: WHL KJH. Wrote the paper: CTW. |
ISSN: | 1932-6203 1932-6203 |
DOI: | 10.1371/journal.pone.0127974 |