Expression of a mutant p193/CUL7 molecule confers resistance to MG132- and etoposide-induced apoptosis independent of p53 or Parc binding

Biochim Biophys Acta. 2007 Mar;1773(3):358-66. doi: 10.1016/j.bbamcr.2006.11.020. Epub 2006 Dec 15.

Abstract

p193/CUL7 is an E3 ubiquitin ligase initially identified as an SV40 Large T Antigen binding protein. Expression of a dominant interfering variant of mouse p193/CUL7 (designated 1152stop) conferred resistance to MG132- and etoposide-induced apoptosis in U2OS cells. Immune precipitation/Western analyses revealed that endogenous p193/CUL7 formed a complex with Parc (a recently identified parkin-like ubiquitin ligase) and p53. Apoptosis resistance did not result from 1152stop-mediated disruption of the endogenous p193/CUL7 binding partners. Moreover, 1152stop molecule did not directly bind to endogenous p193/CUL7, Parc or p53. These data suggested a role for p193/CUL7 in the regulation of apoptosis independently of p53 and Parc activity.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Apoptosis / drug effects*
  • Cell Line
  • Cullin Proteins / genetics
  • Cullin Proteins / immunology
  • Cullin Proteins / metabolism*
  • Cytoplasm / metabolism
  • DNA Topoisomerase IV / metabolism
  • Drug Resistance*
  • Enzyme Activation / drug effects
  • Etoposide / pharmacology*
  • Gene Expression / drug effects*
  • Humans
  • Leupeptins / pharmacology*
  • Mice
  • Mutation / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Proteasome Inhibitors
  • Protein Binding
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • Antibodies, Monoclonal
  • Cul7 protein, mouse
  • Cullin Proteins
  • Leupeptins
  • Proteasome Inhibitors
  • Tumor Suppressor Protein p53
  • Etoposide
  • Proteasome Endopeptidase Complex
  • DNA Topoisomerase IV
  • benzyloxycarbonylleucyl-leucyl-leucine aldehyde