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J Biol Chem. 2013 May 31;288(22):15474-80. doi: 10.1074/jbc.M112.416735. Epub 2013 Apr 23.

HIV-1 Vpr protein inhibits telomerase activity via the EDD-DDB1-VPRBP E3 ligase complex.

Author information

1
Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.

Abstract

Viral pathogens utilize host cell machinery for their benefits. Herein, we identify that HIV-1 Vpr (viral protein R) negatively modulates telomerase activity. Telomerase enables stem and cancer cells to evade cell senescence by adding telomeric sequences to the ends of chromosomes. We found that Vpr inhibited telomerase activity by down-regulating TERT protein, a catalytic subunit of telomerase. As a molecular adaptor, Vpr enhanced the interaction between TERT and the VPRBP substrate receptor of the DYRK2-associated EDD-DDB1-VPRBP E3 ligase complex, resulting in increased ubiquitination of TERT. In contrast, the Vpr mutant identified in HIV-1-infected long-term nonprogressors failed to promote TERT destabilization. Our results suggest that Vpr inhibits telomerase activity by hijacking the host E3 ligase complex, and we propose the novel molecular mechanism of telomerase deregulation in possibly HIV-1 pathogenesis.

KEYWORDS:

DYRK2; EDD; HIV-1; Protein Degradation; TERT; Telomerase; Telomeres; Ubiquitination; VPRBP; Vpr

PMID:
23612978
PMCID:
PMC3668709
DOI:
10.1074/jbc.M112.416735
[Indexed for MEDLINE]
Free PMC Article

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