Topors acts as a SUMO-1 E3 ligase for p53 in vitro and in vivo

FEBS Lett. 2005 Sep 12;579(22):5007-12. doi: 10.1016/j.febslet.2005.07.088.

Abstract

Human Topors, which was originally identified as cellular binding partner of DNA topoisomerase I and of p53, has recently been shown to function as an ubiquitin E3 ligase for p53 in a manner dependent on its N'-terminally located RING finger. Here, we demonstrate that Topors also enhances the conjugation of the small ubiquitin-like modifier 1 (SUMO-1) to p53 in vivo and in a reconstituted in vitro system. The Topors SUMO-1 E3 ligase activity does not depend upon its RING finger motif. In HeLa cells, Topors induced p53 sumoylation was accompanied by an increase in endogenous p53 protein levels. Furthermore, Topors enhances the sumoylation of a variety of other, yet unidentified, cellular proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • DNA Topoisomerases, Type I / genetics
  • DNA Topoisomerases, Type I / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Humans
  • In Vitro Techniques
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • SUMO-1 Protein / genetics
  • SUMO-1 Protein / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*
  • Zinc Fingers

Substances

  • Carrier Proteins
  • DNA-Binding Proteins
  • Neoplasm Proteins
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • SUMO-1 Protein
  • Transcription Factors
  • Tumor Suppressor Protein p53
  • TOPORS protein, human
  • Ubiquitin-Protein Ligases
  • DNA Topoisomerases, Type I