Genetic Flexibility of the NKNK Motif in HIV-1 Integrases Allows Its Involvement in Multiple Functions During Infection

ABSTRACTUsing coevolution-network interference based on the comparison of two phylogenetically distantly related isolates, one from the main group M and the other from the minor group O of HIV-1, we identify, in the C-terminal domain (CTD) of integrase, a new functional motif constituted by four non-contiguous amino acids (N222K240N254K273). Mutating the lysines abolishes integration through decreased 3’-processing and inefficient nuclear import of reverse transcribed genomes. Solution of the crystal structures of wt and mutated CTDs shows that the motif generates a positive surface potential that is important for integration. The number of charges in the motif appears more crucial than their position within the motif. Indeed, the positions of the K could be permutated or additional K could be inserted in the motif, generally without affecting integration per se. Despite this potential genetic flexibility, the NKNK arrangement is strictly conserved in natural sequences, indicative of an effective purifying selection exerted at steps other than integration. Accordingly, reverse transcription was reduced even in the mutants that retained wt integration levels, indicating that specifically the wt sequence is optimal for carrying out the multiple functions integrase exerts. We propose that the existence of several amino acids arrangements within the motif, with comparable efficiencies of integration per se, might have constituted an asset for the acquisition of additional functions during viral evolution.IMPORTANCEIntensive studies on HIV-1 have revealed its extraordinary ability to adapt to environmental and immunological challenges, an ability that is also at the basis of antiviral treatments escape. Here, by deconvoluting the different roles of the viral integrase in the various steps of the infectious cycle, we report how the existence of alternative equally efficient structural arrangements for carrying out one function opens on the possibility of adapting to the optimisation of further functionalities exerted by the same protein. Such property provides an asset to increase the efficiency of the infectious process. On the other hand, though, the identification of this new motif provides a potential target for interfering simultaneously with multiple functions of the protein.

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Comparison of Cell Cycle Arrest, Transactivation, and Apoptosis Induced by the Simian Immunodeficiency Virus SIVagm and Human Immunodeficiency Virus Type 1 vpr Genes

Journal of Virology ◽

10.1128/jvi.75.8.3791-3801.2001 ◽

2001 ◽

Vol 75 (8) ◽

pp. 3791-3801 ◽

Cited By ~ 62

Author(s):

Yonghong Zhu ◽

Harris A. Gelbard ◽

Mikhail Roshal ◽

Shannon Pursell ◽

Beth D. Jamieson ◽

...

Keyword(s):

Cell Cycle ◽

Human Immunodeficiency Virus ◽

Amino Acid ◽

Multiple Functions ◽

Acid Protein ◽

Immunodeficiency Virus ◽

Induction Of Apoptosis ◽

Hiv 1 ◽

Amino Acid Protein

ABSTRACT All primate lentiviruses known to date contain one or two open reading frames with homology to the human immunodeficiency virus type 1 (HIV-1) vpr gene. HIV-1 vpr encodes a 96-amino-acid protein with multiple functions in the viral life cycle. These functions include modulation of the viral replication kinetics, transactivation of the long terminal repeat, participation in the nuclear import of preintegration complexes, induction of G2arrest, and induction of apoptosis. The simian immunodeficiency virus (SIV) that infects African green monkeys (SIVagm) contains avpr homologue, which encodes a 118-amino-acid protein. SIVagm vpr is structurally and functionally related to HIV-1 vpr. The present study focuses on how three specific functions (transactivation, induction of G2 arrest, and induction of apoptosis) are related to one another at a functional level, for HIV-1 and SIVagm vpr. While our study supports previous reports demonstrating a causal relationship between induction of G2 arrest and transactivation for HIV-1 vpr, we demonstrate that the same is not true for SIVagm vpr. Transactivation by SIVagm vpr is independent of cell cycle perturbation. In addition, we show that induction of G2arrest is necessary for the induction of apoptosis by HIV-1vpr but that the induction of apoptosis by SIVagmvpr is cell cycle independent. Finally, while SIVagmvpr retains its transactivation function in human cells, it is unable to induce G2 arrest or apoptosis in such cells, suggesting that the cytopathic effects of SIVagm vpr are species specific. Taken together, our results suggest that while the multiple functions of vpr are conserved between HIV-1 and SIVagm, the mechanisms leading to the execution of such functions are divergent.

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Identification of the Cellular Prohibitin 1/Prohibitin 2 Heterodimer as an Interaction Partner of the C-Terminal Cytoplasmic Domain of the HIV-1 Glycoprotein

Journal of Virology ◽

10.1128/jvi.01641-09 ◽

2009 ◽

Vol 84 (3) ◽

pp. 1355-1365 ◽

Cited By ~ 43

Author(s):

Vanessa Emerson ◽

Denise Holtkotte ◽

Tanya Pfeiffer ◽

I-Hsuan Wang ◽

Martina Schnölzer ◽

...

Keyword(s):

Cytoplasmic Domain ◽

Cellular Proteins ◽

Spectrometric Analysis ◽

Wild Type ◽

Double Mutation ◽

Multiple Functions ◽

A Cell ◽

Specificity Of Binding ◽

Prohibitin 1 ◽

Hiv 1

ABSTRACT Our studies aim to elucidate the functions carried out by the very long, and in its length highly conserved, C-terminal cytoplasmic domain (Env-CT) of the HIV-1 glycoprotein. Mass spectrometric analysis of cellular proteins bound to a tagged version of the HIV Env-CT led to the identification of the prohibitin 1 and 2 proteins (Phb1 and Phb2). These ubiquitously expressed proteins, which exist as stable heterodimers, have been shown to have multiple functions within cells and to localize to multiple cellular and extracellular compartments. The specificity of binding of the Phb1/Phb2 complex to the Env-CT was confirmed in various manners, including coimmunoprecipitation with authentic provirally encoded, full-length Env. Strong binding was dependent on Env residues 790 to 800 and could be severely inhibited by the double mutation L799R/L800Q but not by mutation of these amino acids individually. Analysis of the respective mutant virions revealed that their different abilities to bind Phb1/Phb2 correlated with their replicative properties. Thus, mutated virions with single mutations [HIV-Env-(L799R) and HIV-Env-(L800Q)] replicated similarly to wild-type HIV, but HIV-Env-(L799R/L800Q) virions, which cannot bind Phb1/Phb2, exhibited a cell-dependent replicative phenotype similar to that of HIV-Env-Tr712, lacking the entire Env-CT domain. Thus, replicative spread was achieved, although somewhat delayed, in “permissive” MT-4 cells but failed to occur in “nonpermissive” H9 T cells. These results point to binding of the Phb1/Phb2 complex to the Env-CT as being of importance for replicative spread in nonpermissive cells, possibly by modulating critical Phb-dependent cellular process(es).

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NKNK: a New Essential Motif in the C-Terminal Domain of HIV-1 Group M Integrases

Journal of Virology ◽

10.1128/jvi.01035-20 ◽

2020 ◽

Vol 94 (20) ◽

Author(s):

Marine Kanja ◽

Pierre Cappy ◽

Nicolas Levy ◽

Oyndamola Oladosu ◽

Sylvie Schmidt ◽

...

Keyword(s):

Antiviral Treatment ◽

Viral Evolution ◽

Purifying Selection ◽

The Other ◽

Functional Motif ◽

Multiple Functions ◽

Terminal Domain ◽

Per Se ◽

Infectious Cycle ◽

Hiv 1

ABSTRACT Using coevolution network interference based on comparison of two phylogenetically distantly related isolates, one from the main group M and the other from the minor group O of HIV-1, we identify, in the C-terminal domain (CTD) of integrase, a new functional motif constituted by four noncontiguous amino acids (N222K240N254K273). Mutating the lysines abolishes integration through decreased 3′ processing and inefficient nuclear import of reverse-transcribed genomes. Solution of the crystal structures of wild-type (wt) and mutated CTDs shows that the motif generates a positive surface potential that is important for integration. The number of charges in the motif appears more crucial than their position within the motif. Indeed, the positions of the K’s could be permutated or additional K’s could be inserted in the motif, generally without affecting integration per se. Despite this potential genetic flexibility, the NKNK arrangement is strictly conserved in natural sequences, indicative of an effective purifying selection exerted at steps other than integration. Accordingly, reverse transcription was reduced even in the mutants that retained wt integration levels, indicating that specifically the wt sequence is optimal for carrying out the multiple functions that integrase exerts. We propose that the existence of several amino acid arrangements within the motif, with comparable efficiencies of integration per se, might have constituted an asset for the acquisition of additional functions during viral evolution. IMPORTANCE Intensive studies of HIV-1 have revealed its extraordinary ability to adapt to environmental and immunological challenges, an ability that is also at the basis of antiviral treatment escape. Here, by deconvoluting the different roles of the viral integrase in the various steps of the infectious cycle, we report how the existence of alternative equally efficient structural arrangements for carrying out one function opens up the possibility of adapting to the optimization of further functionalities exerted by the same protein. Such a property provides an asset to increase the efficiency of the infectious process. On the other hand, though, the identification of this new motif provides a potential target for interfering simultaneously with multiple functions of the protein.

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The multiple functions of HIV-1 Tat: proliferation versus apoptosis

Frontiers in Bioscience ◽

10.2741/1829 ◽

2006 ◽

Vol 11 (1) ◽

pp. 708 ◽

Cited By ~ 52

Author(s):

Francesca Peruzzi

Keyword(s):

Multiple Functions ◽

Hiv 1

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Extensive Mutagenesis of the Conserved Box E Motif in Duck Hepatitis B Virus P Protein Reveals Multiple Functions in Replication and a Common Structure with the Primer Grip in HIV-1 Reverse Transcriptase

Journal of Virology ◽

10.1128/jvi.00011-12 ◽

2012 ◽

Vol 86 (12) ◽

pp. 6394-6407 ◽

Cited By ~ 14

Author(s):

Y.-X. Wang ◽

C. Luo ◽

D. Zhao ◽

J. Beck ◽

M. Nassal

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Reverse Transcriptase ◽

Duck Hepatitis B Virus ◽

Multiple Functions ◽

Common Structure ◽

Duck Hepatitis ◽

P Protein ◽

B Virus ◽

Hiv 1

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Ultrastructural observations of human monocytes infected with HIV-1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084843 ◽

1991 ◽

Vol 49 ◽

pp. 108-109

Author(s):

James K. Koehler ◽

Steven G. Reed ◽

Joao S. Silva

Keyword(s):

Gradient Centrifugation ◽

Virus Production ◽

Human Monocyte ◽

Red Cross ◽

Human Monocytes ◽

Blood Monocytes ◽

Hiv Replication ◽

Electron Microscopic ◽

Ultrastructural Studies ◽

Hiv 1

As part of a larger study involving the co-infection of human monocyte cultures with HIV and protozoan parasites, electron microscopic observations were made on the course of HIV replication and infection in these cells. Although several ultrastructural studies of the cytopathology associated with HIV infection have appeared, few studies have shown the details of virus production in “normal,” human monocytes/macrophages, one of the natural targets of the virus, and suspected of being a locus of quiescent virus during its long latent period. In this report, we detail some of the interactions of developing virons with the membranes and organelles of the monocyte host.Peripheral blood monocytes were prepared from buffy coats (Portland Red Cross) by Percoll gradient centrifugation, followed by adherence to cover slips. 90-95% pure monocytes were cultured in RPMI with 5% non-activated human AB serum for four days and infected with 100 TCID50/ml of HIV-1 for four hours, washed and incubated in fresh medium for 14 days.

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