Frequency of Direct Repeat Deletion in a Human Immunodeficiency Virus Type 1 Vector during Reverse Transcription in Human Cells

ABSTRACT Proteasomal degradation of APOBEC3G is a critical step for human immunodeficiency virus type 1 (HIV-1) replication. However, the necessity for polyubiquitination of APOBEC3G in this process is still controversial. In this study, we showed that although macaque simian immunodeficiency virus (SIVmac) Vif is more stable than HIV-1 Vif in human cells, SIVmac Vif induces degradation of APBOEC3G as efficiently as HIV-1 Vif. Overexpression of APOBEC3G or lysine-free APOBEC3G stabilized HIV-1 Vif, indicating that APOBEC3G degradation is independent of the degradation of Vif. Furthermore, an in vivo polyubiquitination assay showed that lysine-free APOBEC3G was also polyubiquitinated. These data suggest that polyubiquitination of APOBEC3G, not that of HIV-1 Vif, is crucial for APOBEC3G degradation.

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Activation of human immunodeficiency virus type 1 by DNA damage in human cells

Nature ◽

10.1038/333078a0 ◽

1988 ◽

Vol 333 (6168) ◽

pp. 78-81 ◽

Cited By ~ 166

Author(s):

Kristoffer Valerie ◽

Anne Delers ◽

Claudine Bruck ◽

Clotilde Thiriart ◽

Hagai Rosenberg ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Dna Damage ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Human Cells ◽

Immunodeficiency Virus

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Inhibition of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{tRNA}_{3}^{\mathrm{Lys}}\) \end{document}-Primed Reverse Transcription by Human APOBEC3G during Human Immunodeficiency Virus Type 1 Replication

Journal of Virology ◽

10.1128/jvi.01038-06 ◽

2006 ◽

Vol 80 (23) ◽

pp. 11710-11722 ◽

Cited By ~ 147

Author(s):

Fei Guo ◽

Shan Cen ◽

Meijuan Niu ◽

Jenan Saadatmand ◽

Lawrence Kleiman

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Reverse Transcription ◽

Viral Infectivity ◽

Viral Dna ◽

Immunodeficiency Virus ◽

Dna Production ◽

Hiv 1

ABSTRACT Cells are categorized as being permissive or nonpermissive according to their ability to produce infectious human immunodeficiency virus type 1 (HIV-1) lacking the viral protein Vif. Nonpermissive cells express the human cytidine deaminase APOBEC3G (hA3G), and Vif has been shown to bind to APOBEC3G and facilitate its degradation. Vif-negative HIV-1 virions produced in nonpermissive cells incorporate hA3G and have a severely reduced ability to produce viral DNA in newly infected cells. While it has been proposed that the reduction in DNA production is due to hA3G-facilitated deamination of cytidine, followed by DNA degradation, we provide evidence here that a decrease in the synthesis of the DNA by reverse transcriptase may account for a significant part of this reduction. During the infection of cells with Vif-negative HIV-1 produced from 293T cells transiently expressing hA3G, much of the inhibition of early (≥50% reduction) and late (≥95% reduction) viral DNA production, and of viral infectivity (≥95% reduction), can occur independently of DNA deamination. The inhibition of the production of early minus-sense strong stop DNA is also correlated with a similar inability of tRNA3 Lys to prime reverse transcription. A similar reduction in tRNA3 Lys priming and viral infectivity is also seen in the naturally nonpermissive cell H9, albeit at significantly lower levels of hA3G expression.

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Effects of Varying Sequence Similarity on the Frequency of Repeat Deletion during Reverse Transcription of a Human Immunodeficiency Virus Type 1 Vector

Journal of Virology ◽

10.1128/jvi.76.15.7897-7902.2002 ◽

2002 ◽

Vol 76 (15) ◽

pp. 7897-7902 ◽

Cited By ~ 37

Author(s):

Wenfeng An ◽

Alice Telesnitsky

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Reverse Transcription ◽

Genetic Recombination ◽

Gene Segment ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Deletion Frequency

ABSTRACT Genetic recombination contributes to human immunodeficiency virus type 1 (HIV-1) diversity, with homologous recombination being more frequent than nonhomologous recombination. In this study, HIV-1-based vectors were used to assay the effects of various extents of sequence divergence on the frequency of the recombination-related property of repeat deletion. Sequence variation, similar in degree to that which differentiates natural HIV-1 isolates, was introduced by synonymous substitutions into a gene segment. Repeated copies of this segment were then introduced into assay vectors. With the use of a phenotypic screen, the deletion frequency of identical repeats was compared to the frequencies of repeats that differed in sequence by various extents. During HIV-1 reverse transcription, the deletion frequency observed with repeats that differed by 5% was 65% of that observed with identical repeats. The deletion frequency decreased to 26% for repeats that differed by 9%, and when repeats differed by 18%, the deletion frequency was about 5% of the identical repeat value. Deletion frequencies fell to less than 0.3% of identical repeat values when genetic distances of 27% or more were examined. These data argue that genetic variation is not as inhibitory to HIV-1 repeat deletion as it is to the corresponding cellular process and suggest that, for sequences that differ by about 25% or more, HIV-1 recombination directed by sequence homology may be no more frequent than that which is homology independent.

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Forced Selection of a Human Immunodeficiency Virus Type 1 Variant That Uses a Non-Self tRNA Primer for Reverse Transcription: Involvement of Viral RNA Sequences and the Reverse Transcriptase Enzyme

Journal of Virology ◽

10.1128/jvi.78.19.10706-10714.2004 ◽

2004 ◽

Vol 78 (19) ◽

pp. 10706-10714 ◽

Cited By ~ 25

Author(s):

Truus E. M. Abbink ◽

Nancy Beerens ◽

Ben Berkhout

Keyword(s):

Human Immunodeficiency Virus ◽

Reverse Transcriptase ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Reverse Transcription ◽

Viral Rna ◽

Replication Capacity ◽

Immunodeficiency Virus ◽

Trna Primer

ABSTRACT Human immunodeficiency virus type 1 uses the tRNA3 Lys molecule as a selective primer for reverse transcription. This primer specificity is imposed by sequence complementarity between the tRNA primer and two motifs in the viral RNA genome: the primer-binding site (PBS) and the primer activation signal (PAS). In addition, there may be specific interactions between the tRNA primer and viral proteins, such as the reverse transcriptase (RT) enzyme. We constructed viruses with mutations in the PAS and PBS that were designed to employ the nonself primer tRNAPro or tRNA1,2 Lys. These mutants exhibited a severe replication defect, indicating that additional adaptation of the mutant virus is required to accommodate the new tRNA primer. Multiple independent virus evolution experiments were performed to select for fast-replicating variants. Reversion to the wild-type PBS-lys3 sequence was the most frequent escape route. However, we identified one culture in which the virus gained replication capacity without reversion of the PBS. This revertant virus eventually optimized the PAS motif for interaction with the nonself primer. Interestingly, earlier evolution samples revealed a single amino acid change of an otherwise well-conserved residue in the RNase H domain of the RT enzyme, implicating this domain in selective primer usage. We demonstrate that both the PAS and RT mutations improve the replication capacity of the tRNA1,2 Lys-using virus.

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