Abstract
Control of RNA processing plays a major role in HIV-1 gene expression. To explore the role of several hnRNP proteins in this process, we carried out a siRNA screen to examine the effect of depletion of hnRNPs A1, A2, D, H, I and K on HIV-1 gene expression. While loss of hnRNPs H, I or K had little effect, depletion of A1 and A2 increased expression of viral structural proteins. In contrast, reduced hnRNP D expression decreased synthesis of HIV-1 Gag and Env. Loss of hnRNP D induced no changes in viral RNA abundance but reduced the accumulation of HIV-1 unspliced and singly spliced RNAs in the cytoplasm. Subsequent analyses determined that hnRNP D underwent relocalization to the cytoplasm upon HIV-1 infection and was associated with Gag protein. Screening of the four isoforms of hnRNP D determined that, upon overexpression, they had differential effects on HIV-1 Gag expression, p45 and p42 isoforms increased viral Gag synthesis while p40 and p37 suppressed it. The differential effect of hnRNP D isoforms on HIV-1 expression suggests that their relative abundance could contribute to the permissiveness of cell types to replicate the virus, a hypothesis subsequently confirmed by selective depletion of p45 and p42.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Gene Expression*
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HIV-1 / genetics*
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HIV-1 / metabolism
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HeLa Cells
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Heterogeneous Nuclear Ribonucleoprotein D0
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Heterogeneous-Nuclear Ribonucleoprotein D / antagonists & inhibitors
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Heterogeneous-Nuclear Ribonucleoprotein D / genetics
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Heterogeneous-Nuclear Ribonucleoprotein D / physiology*
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Heterogeneous-Nuclear Ribonucleoprotein Group A-B / antagonists & inhibitors
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Heterogeneous-Nuclear Ribonucleoprotein Group A-B / genetics
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Heterogeneous-Nuclear Ribonucleoprotein Group A-B / physiology
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Humans
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Protein Isoforms / antagonists & inhibitors
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Protein Isoforms / genetics
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Protein Isoforms / physiology
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RNA Interference
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RNA, Viral / analysis
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env Gene Products, Human Immunodeficiency Virus / genetics
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env Gene Products, Human Immunodeficiency Virus / metabolism
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gag Gene Products, Human Immunodeficiency Virus / genetics
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gag Gene Products, Human Immunodeficiency Virus / metabolism
Substances
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HNRNPD protein, human
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Heterogeneous Nuclear Ribonucleoprotein D0
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Heterogeneous-Nuclear Ribonucleoprotein D
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Heterogeneous-Nuclear Ribonucleoprotein Group A-B
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Protein Isoforms
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RNA, Viral
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env Gene Products, Human Immunodeficiency Virus
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gag Gene Products, Human Immunodeficiency Virus