Identification of a novel RING finger protein as a coregulator in steroid receptor-mediated gene transcription

Mol Cell Biol. 1998 Sep;18(9):5128-39. doi: 10.1128/MCB.18.9.5128.


Using the DNA-binding domain of androgen receptor (AR) as a bait in a yeast two-hybrid screening, we have identified a small nuclear RING finger protein, termed SNURF, that interacts with AR in a hormone-dependent fashion in both yeast and mammalian cells. Physical interaction between AR and SNURF was demonstrated by coimmunoprecipitation from cell extracts and by protein-protein affinity chromatography. Rat SNURF is a highly hydrophilic protein consisting of 194 amino acid residues and comprising a consensus C3HC4 zinc finger (RING) structure in the C-terminal region and a bipartite nuclear localization signal near the N terminus. Immunohistochemical experiments indicated that SNURF is a nuclear protein. SNURF mRNA is expressed in a variety of human and rat tissues. Overexpression of SNURF in cultured mammalian cells enhanced not only androgen, glucocorticoid, and progesterone receptor-dependent transactivation but also basal transcription from steroid-regulated promoters. Mutation of two of the potential Zn2+ coordinating cysteines to serines in the RING finger completely abolished the ability of SNURF to enhance basal transcription, whereas its ability to activate steroid receptor-dependent transcription was maintained, suggesting that there are separate domains in SNURF that mediate interactions with different regulatory factors. SNURF is capable of interacting in vitro with the TATA-binding protein, and the RING finger domain is needed for this interaction. Collectively, we have identified and characterized a ubiquitously expressed RING finger protein, SNURF, that may function as a bridging factor and regulate steroid receptor-dependent transcription by a mechanism different from those of previously identified coactivator or integrator proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CHO Cells
  • COS Cells
  • Cell Line
  • Cloning, Molecular
  • Cricetinae
  • Gene Expression Regulation*
  • Gene Library
  • HeLa Cells
  • Humans
  • Male
  • Mice
  • Molecular Sequence Data
  • Nuclear Proteins / biosynthesis
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • Rats
  • Receptors, Androgen / metabolism*
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / metabolism
  • TATA Box
  • Testis / metabolism
  • Transcription Factors / biosynthesis
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism*
  • Transcription, Genetic*
  • Transcriptional Activation
  • Transfection
  • Ubiquitin-Protein Ligases
  • Zinc Fingers*


  • Nuclear Proteins
  • RNF4 protein, human
  • Receptors, Androgen
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Rnf4 protein, mouse
  • Rnf4 protein, rat
  • Ubiquitin-Protein Ligases

Associated data

  • GENBANK/AF022081