scholarly journals Alternative splicing of human immunodeficiency virus type 1 mRNA modulates viral protein expression, replication, and infectivity.

1993 ◽  
Vol 67 (11) ◽  
pp. 6365-6378 ◽  
Author(s):  
D F Purcell ◽  
M A Martin
Keyword(s):  
Human Immunodeficiency Virus ◽  
Alternative Splicing ◽  
Protein Expression ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Protein ◽  
Viral Protein Expression ◽  
Immunodeficiency Virus

scholarly journals Double-Stranded RNA Adenosine Deaminases Enhance Expression of Human Immunodeficiency Virus Type 1 Proteins

2008 ◽  
Vol 82 (21) ◽  
pp. 10864-10872 ◽  
Author(s):  
Angsana Phuphuakrat ◽  
Romchat Kraiwong ◽  
Chompunuch Boonarkart ◽  
Darat Lauhakirti ◽  
Tun-Hou Lee ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protein Expression ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Structural Protein ◽  
Double Stranded Rna ◽  
Adenosine Deaminases ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT ADARs (adenosine deaminases that act on double-stranded RNA) are RNA editing enzymes that catalyze a change from adenosine to inosine, which is then recognized as guanosine by translational machinery. We demonstrate here that overexpression of ADARs but not of an ADAR mutant lacking editing activity could upregulate human immunodeficiency virus type 1 (HIV-1) structural protein expression and viral production. Knockdown of ADAR1 by RNA silencing inhibited HIV-1 production. Viral RNA harvested from transfected ADAR1-knocked-down cells showed a decrease in the level of unspliced RNA transcripts. Overexpression of ADAR1 induced editing at a specific site in the env gene, and a mutant with the edited sequence was expressed more efficiently than the wild-type viral genome. These data suggested the role of ADAR in modulation of HIV-1 replication. Our data demonstrate a novel mechanism in which HIV-1 employs host RNA modification machinery for posttranscriptional regulation of viral protein expression.

scholarly journals CCR5Δ32 Protein Expression and Stability Are Critical for Resistance to Human Immunodeficiency Virus Type 1 In Vivo

2007 ◽  
Vol 81 (15) ◽  
pp. 8041-8049 ◽  
Author(s):  
Lokesh Agrawal ◽  
Qingwen Jin ◽  
Jeff Altenburg ◽  
L. Meyer ◽  
R. Tubiana ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protein Expression ◽  
Protective Effect ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Immunodeficiency Virus ◽  
Low Levels ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection of individuals carrying the two alleles of the CCR5Δ32 mutation (CCR5−/−) has rarely been reported, but how the virus overcomes the CCR5Δ32 protective effect in these cases has not been delineated. We have investigated this in 6 infected (HIV+) and 25 HIV− CCR5−/− individuals. CD4+ T lymphocytes isolated from HIV− CCR5−/− peripheral blood mononuclear cells (PBMCs) showed lower levels of CXCR4 expression that correlated with lower X4 Env-mediated fusion. Endogenous CCR5Δ32 protein was detected in all HIV− CCR5−/− PBMC samples (n = 25) but not in four of six unrelated HIV+ CCR5−/− PBMC samples. Low levels were detected in another two HIV+ CCR5−/− PBMC samples. The expression of adenovirus 5 (Ad5)-encoded CCR5Δ32 protein restored the protective effect in PBMCs from three HIV+ CCR5−/− individuals but failed to restore the protective effect in PBMCs isolated from another three HIV+ CCR5−/− individuals. In the latter samples, pulse-chase analyses demonstrated the disappearance of endogenous Ad5-encoded CCR5Δ32 protein and the accumulation of Ad5-encoded CCR5 during the chase periods. PBMCs isolated from CCR5−/− individuals showed resistance to primary X4 but were readily infected by a lab-adapted X4 strain. Low levels of Ad5-encoded CCR5Δ32 protein conferred resistance to primary X4 but not to lab-adapted X4 virus. These data provide strong support for the hypothesis that the CCR5Δ32 protein actively confers resistance to HIV-1 in vivo and suggest that the loss or reduction of CCR5Δ32 protein expression may account for HIV-1 infection of CCR5−/− individuals. The results also suggest that other cellular or virally induced factors may be involved in the stability of CCR5Δ32 protein.

scholarly journals Production of Uninfectious Human Immunodeficiency Virus Type 1 Containing Viral Protein R Fused to a Single-Chain Antibody against Viral Integrase

1998 ◽  
Vol 72 (8) ◽  
pp. 6960-6964 ◽  
Author(s):  
Nobuo Okui ◽  
Noriko Kobayashi ◽  
Yoshihiro Kitamura
Keyword(s):  
Human Immunodeficiency Virus ◽  
Fusion Protein ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Protein ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT A single-chain antibody (scAb) against human immunodeficiency virus type 1 (HIV-1) integrase was expressed as a fusion protein of scAb and HIV-1 viral protein R (Vpr), together with the HIV-1 genome, in human 293T cells. The expression did not affect virion production much but markedly reduced the infectivity of progeny virions. The fusion protein was found to be incorporated into the virions. The incorporation appears to account for the reduced infectivity.

scholarly journals Efficient DNA Transfection Mediated by the C-Terminal Domain of Human Immunodeficiency Virus Type 1 Viral Protein R

2000 ◽  
Vol 74 (12) ◽  
pp. 5424-5431 ◽  
Author(s):  
Antoine Kichler ◽  
Jean-Christophe Pages ◽  
Christian Leborgne ◽  
Sabine Druillennec ◽  
Christine Lenoir ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Life Cycle ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Protein ◽  
Dna Transfection ◽  
Gag Protein ◽  
Viral Protein R ◽  
Immunodeficiency Virus

ABSTRACT Viral protein R (Vpr) of human immunodeficiency virus type 1 is produced late in the virus life cycle and is assembled into the virion through binding to the Gag protein. It is known to play a significant role early in the viral life cycle by facilitating the nuclear import of the preintegration complex in nondividing cells. Vpr is also able to interact with nucleic acids, and we show here that it induces condensation of plasmid DNA. We have explored the possibility of using these properties in DNA transfection experiments. We report that the C-terminal half of the protein (Vpr52–96) mediates DNA transfection in a variety of human and nonhuman cell lines with efficiencies comparable to those of the best-known transfection agents. Compared with polylysine, a standard polycationic transfection reagent, Vpr52–96 was 10- to 1,000-fold more active. Vpr52–96-DNA complexes were able to reach the cell nucleus through a pH-independent mechanism. These observations possibly identify an alternate pathway for DNA transfection.

scholarly journals Viral Protein U (Vpu)-Mediated Enhancement of Human Immunodeficiency Virus Type 1 Particle Release Depends on the Rate of Cellular Proliferation

2001 ◽  
Vol 75 (14) ◽  
pp. 6714-6718 ◽  
Author(s):  
Aparna Deora ◽  
Lee Ratner
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Protein ◽  
Cellular Proliferation ◽  
Expression System ◽  
Particle Release ◽  
Viral Protein U ◽  
Immunodeficiency Virus

ABSTRACT Viral protein U (Vpu) is a 17-kDa phosphoprotein that enhances the release of viral particles from human immunodeficiency virus type 1-infected cells. This study shows that the effect of Vpu on efficient particle release depends on the rate of cell proliferation. Cells arrested by contact inhibition, chemical arresting agents, or terminal differentiation (i.e., macrophages) all exhibited a striking dependence on Vpu for efficient particle release, as shown by examination of particle production from transfections with full-length clones, infections, and the vaccinia virus expression system. In contrast, actively proliferating cells did not exhibit enhanced particle release with Vpu expression. This study demonstrates the necessity of Vpu for efficient viral particle release from quiescent cells.

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