von Hippel Lindau binding protein 1-mediated degradation of integrase affects HIV-1 gene expression at a postintegration step

Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13615-20. doi: 10.1073/pnas.0705162104. Epub 2007 Aug 13.

Abstract

HIV-1 integrase, the viral enzyme responsible for provirus integration into the host genome, can be actively degraded by the ubiquitin-proteasome pathway. Here, we identify von Hippel-Lindau binding protein 1(VBP1), a subunit of the prefoldin chaperone, as an integrase cellular binding protein that bridges interaction between integrase and the cullin2 (Cul2)-based von Hippel-Lindau (VHL) ubiquitin ligase. We demonstrate that VBP1 and Cul2/VHL are required for proper HIV-1 expression at a step between integrase-dependent proviral integration into the host genome and transcription of viral genes. Using both an siRNA approach and Cul2/VHL mutant cells, we show that VBP1 and the Cul2/VHL ligase cooperate in the efficient polyubiquitylation of integrase and its subsequent proteasome-mediated degradation. Results presented here support a role for integrase degradation by the prefoldin-VHL-proteasome pathway in the integration-transcription transition of the viral replication cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cytoskeletal Proteins
  • Gene Expression Regulation, Viral*
  • HIV Integrase / genetics
  • HIV Integrase / metabolism*
  • HIV-1 / genetics
  • HIV-1 / metabolism*
  • HeLa Cells
  • Humans
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Transcription, Genetic / genetics
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Virus Internalization*

Substances

  • Carrier Proteins
  • Cytoskeletal Proteins
  • Molecular Chaperones
  • VBP1 protein, human
  • prefoldin
  • Ubiquitin-Protein Ligases
  • HIV Integrase
  • Proteasome Endopeptidase Complex