HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing

Sci Rep. 2019 Sep 11;9(1):13154. doi: 10.1038/s41598-019-48689-x.

Abstract

Mammals have evolved many antiviral factors impacting different steps of the viral life cycle. Associated with chromatin-modifying enzymes, the cellular cofactor CTIP2 contributes to HIV-1 gene silencing in latently infected reservoirs that constitute the major block toward an HIV cure. We report, for the first time, that the virus has developed a strategy to overcome this major transcriptional block. Productive HIV-1 infection results in a Vpr-mediated depletion of CTIP2 in microglial cells and CD4+ T cells, two of the major viral reservoirs. Associated to the Cul4A-DDB1-DCAF1 ubiquitin ligase complex, Vpr promotes CTIP2 degradation via the proteasome pathway in the nuclei of target cells and notably at the latent HIV-1 promoter. Importantly, Vpr targets CTIP2 associated with heterochromatin-promoting enzymes dedicated to HIV-1 gene silencing. Thereby, Vpr reactivates HIV-1 expression in a microglial model of HIV-1 latency. Altogether our results suggest that HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cells, Cultured
  • Gene Expression Regulation, Viral
  • Gene Silencing*
  • HEK293 Cells
  • HIV Infections / virology
  • HIV-1 / genetics*
  • HIV-1 / metabolism
  • HIV-1 / physiology
  • Host-Pathogen Interactions / genetics
  • Humans
  • Jurkat Cells
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Proteolysis
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism
  • Virus Latency / genetics
  • Virus Replication / genetics
  • vpr Gene Products, Human Immunodeficiency Virus / genetics*
  • vpr Gene Products, Human Immunodeficiency Virus / metabolism

Substances

  • BCL11B protein, human
  • Repressor Proteins
  • Tumor Suppressor Proteins
  • vpr Gene Products, Human Immunodeficiency Virus
  • Proteasome Endopeptidase Complex