Alanine scanning mutagenesis in Cys-His boxes of human immunodeficiency virus type 1 Nucleocapsid protein P7: insight from an in silico investigation.

ABSTRACT An important aspect of the pathophysiology of human immunodeficiency virus type 1 (HIV-1) infection is the ability of the virus to replicate in the host vigorously without a latent phase and to kill cells with a dynamic turnover of 1.8 × 109 cells/day and 10.3 × 109 virions/24 h. The transcription of HIV-1 RNA in acute infection occurs at two stages; the transcription of viral spliced mRNA occurs early, and the transcription of viral genomic RNA occurs later. The HIV-1 Tat protein is translated from the early spliced mRNA and is critical for HIV-1 genomic RNA expression. The cellular transcription factors are important for HIV-1 early spliced mRNA expression. In this study we show that virion nucleocapsid protein (NC) has a role in expression of HIV-1 early spliced mRNA. The HIV-1 NC migrates from the cytoplasm to the nucleus and accumulates in the nucleus at 18 h postinfection. Mutations on HIV-1 NC zinc fingers change the pattern of early viral spliced mRNA expression and result in a delayed expression of early viral mRNA in HIV-infected cells. This delayed HIV-1 early spliced mRNA expression occurs after proviral DNA has been integrated into the cellular genome, as shown by a quantitative integration assay. These results show that virion NC plays an important role in inducing HIV-1 early mRNA expression and contributes to the rapid viral replication that occurs during HIV-1 infection.

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The two zinc fingers in the human immunodeficiency virus type 1 nucleocapsid protein are not functionally equivalent.

Journal of Virology ◽

10.1128/jvi.67.7.4027-4036.1993 ◽

1993 ◽

Vol 67 (7) ◽

pp. 4027-4036 ◽

Cited By ~ 149

Author(s):

R J Gorelick ◽

D J Chabot ◽

A Rein ◽

L E Henderson ◽

L O Arthur

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Nucleocapsid Protein ◽

Zinc Fingers ◽

Immunodeficiency Virus

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Amino-Terminal Substitutions in the CCR5 Coreceptor Impair gp120 Binding and Human Immunodeficiency Virus Type 1 Entry

Journal of Virology ◽

10.1128/jvi.72.1.279-285.1998 ◽

1998 ◽

Vol 72 (1) ◽

pp. 279-285 ◽

Cited By ~ 162

Author(s):

Tatjana Dragic ◽

Alexandra Trkola ◽

Steven W. Lin ◽

Kirsten A. Nagashima ◽

Francis Kajumo ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Surface Glycoprotein ◽

Alanine Scanning Mutagenesis ◽

Cc Chemokine ◽

Amino Terminal ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT The CC-chemokine receptor CCR5 is required for the efficient fusion of macrophage (M)-tropic human immunodeficiency virus type 1 (HIV-1) strains with the plasma membrane of CD4+ cells and interacts directly with the viral surface glycoprotein gp120. Although receptor chimera studies have provided useful information, the domains of CCR5 that function for HIV-1 entry, including the site of gp120 interaction, have not been unambiguously identified. Here, we use site-directed, alanine-scanning mutagenesis of CCR5 to show that substitutions of the negatively charged aspartic acid residues at positions 2 and 11 (D2A and D11A) and a glutamic acid residue at position 18 (E18A), individually or in combination, impair or abolish CCR5-mediated HIV-1 entry for the ADA and JR-FL M-tropic strains and the DH123 dual-tropic strain. These mutations also impair Env-mediated membrane fusion and the gp120-CCR5 interaction. Of these three residues, only D11 is necessary for CC-chemokine-mediated inhibition of HIV-1 entry, which is, however, also dependent on other extracellular CCR5 residues. Thus, the gp120 and CC-chemokine binding sites on CCR5 are only partially overlapping, and the former site requires negatively charged residues in the amino-terminal CCR5 domain.

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