Abstract
Deubiquitinases (DUBs) are key regulators of complex cellular processes. HIV-1 Tat is synthesized early after infection and is mainly responsible for enhancing viral production. Here, we report that one of the DUBs, USP7, stabilized the HIV-1 Tat protein through its deubiquitination. Treatment with either a general DUB inhibitor (PR-619) or USP7-specific inhibitor (P5091) resulted in Tat protein degradation. The USP7-specific inhibitor reduced virus production in a latently infected T-lymphocytic cell line J1.1, which produces large amounts of HIV-1 upon stimulation. A potent increase in Tat-mediated HIV-1 production was observed with USP7 in a dose-dependent manner. As expected, deletion of the USP7 gene using the CRISPR-Cas9 method reduced the Tat protein and supported less virus production. Interestingly, the levels of endogenous USP7 increased after HIV-1 infection in human T-cells (MOLT-3) and in mammalian cells transfected with HIV-1 proviral DNA. Thus, HIV-1 Tat is stabilized by the host cell deubiquitinase USP7, leading to enhanced viral production, and HIV-1 in turn up-regulates the USP7 protein level.
Keywords:
HIV-1; deubiquitination; protein degradation; transactivation.
© 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aminopyridines / pharmacology
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Anti-HIV Agents / pharmacology
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CRISPR-Cas Systems
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Cell Line
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Enzyme Induction / drug effects
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Enzyme Inhibitors / pharmacology
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Genes, Reporter / drug effects
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HEK293 Cells
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HIV-1 / drug effects
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HIV-1 / physiology*
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Host-Pathogen Interactions / drug effects
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Humans
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Jurkat Cells
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Protein Stability / drug effects
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / metabolism
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T-Lymphocytes / drug effects
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T-Lymphocytes / immunology
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T-Lymphocytes / metabolism*
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T-Lymphocytes / virology
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Thiocyanates / pharmacology
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Thiophenes / pharmacology
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Ubiquitin Thiolesterase / antagonists & inhibitors
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Ubiquitin Thiolesterase / genetics
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Ubiquitin Thiolesterase / metabolism*
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Ubiquitin-Specific Peptidase 7
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Ubiquitination / drug effects
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Virus Replication / drug effects
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tat Gene Products, Human Immunodeficiency Virus / chemistry
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tat Gene Products, Human Immunodeficiency Virus / genetics
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tat Gene Products, Human Immunodeficiency Virus / metabolism*
Substances
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2,6-diaminopyridine-3,5-bis(thiocyanate)
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Aminopyridines
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Anti-HIV Agents
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Enzyme Inhibitors
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P5091
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Recombinant Fusion Proteins
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Thiocyanates
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Thiophenes
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tat Gene Products, Human Immunodeficiency Virus
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USP7 protein, human
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Ubiquitin Thiolesterase
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Ubiquitin-Specific Peptidase 7