SUMO-1 promotes association of SNURF (RNF4) with PML nuclear bodies

Exp Cell Res. 2005 Mar 10;304(1):224-33. doi: 10.1016/j.yexcr.2004.10.029. Epub 2004 Nov 23.

Abstract

Small nuclear RING finger protein SNURF (RNF4) is involved in transcriptional and cell growth regulation. We show here that a significant portion of endogenous SNURF localizes to nuclear bodies (NBs) that overlap with or are adjacent to domains containing endogenous promyelocytic leukemia (PML) protein and small ubiquitin-like modifier-1 (SUMO-1). In biochemical assays, SNURF efficiently binds SUMO-1 in a noncovalent fashion. SNURF is also covalently modified by SUMO-1 at nonconsensus attachment sites. Ectopic expression of SUMO-1 markedly enhances the interaction between PML3 (PML IV) and SNURF, but covalent attachment of SUMO-1 to neither protein is required. Moreover, overexpression of PML3, but not PML-L (PML III), abolishes the coactivation function of SNURF in transactivation assays, which parallels the ability of PML3 to recruit SNURF to nuclear bodies. In sum, we have identified SNURF as a novel component in PML bodies and suggest that SUMO-1-facilitated sequestration into these nuclear domains regulates the transcriptional activity of SNURF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Cell Line, Tumor
  • Cell Nucleus Structures / chemistry*
  • Cell Nucleus Structures / ultrastructure
  • Female
  • HeLa Cells
  • Humans
  • Neoplasm Proteins / analysis*
  • Neoplasm Proteins / metabolism
  • Nuclear Proteins / analysis*
  • Nuclear Proteins / metabolism
  • Promyelocytic Leukemia Protein
  • SUMO-1 Protein / physiology*
  • Transcription Factors / analysis*
  • Transcription Factors / metabolism
  • Tumor Suppressor Proteins

Substances

  • Neoplasm Proteins
  • Nuclear Proteins
  • Promyelocytic Leukemia Protein
  • RNF4 protein, human
  • SNURF protein, human
  • SUMO-1 Protein
  • Transcription Factors
  • Tumor Suppressor Proteins
  • PML protein, human