Structure-function analysis of the estrogen receptor alpha corepressor scaffold attachment factor-B1: identification of a potent transcriptional repression domain

J Biol Chem. 2004 Jun 18;279(25):26074-81. doi: 10.1074/jbc.M313726200. Epub 2004 Apr 5.

Abstract

Scaffold attachment factor-B1 (SAFB1) is a nuclear matrix protein that has been proposed to couple chromatin structure, transcription, and RNA processing. We have previously shown that SAFB1 can repress estrogen receptor (ERalpha)-mediated transactivation. Here we present a structure-function study showing that transactivation is mediated via an intrinsic and transferable C-terminal repression domain (RD). A similar C-terminal RD was found in the family member SAFB2. Removal of the RD from SAFB1 resulted in a dominant-negative SAFB1 protein that increased ligand-dependent and -independent ERalpha activity. SAFB1RD-mediated repression was partly blocked by histone deacetylase inhibitors; however, no histone deacetylase inhibitors were identified in a yeast two-hybrid screen using the RD as bait. Instead, SAFB1RD was found to interact with TAFII68, a member of the basal transcription machinery. We propose a model in which SAFB1 represses ERalpha activity via indirect association with histone deacetylation and interaction with the basal transcription machinery.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cell Line, Tumor
  • Enzyme Inhibitors / pharmacology
  • Genes, Dominant
  • Genetic Vectors
  • HeLa Cells
  • Histone Deacetylase Inhibitors
  • Histones / metabolism
  • Humans
  • Immunoblotting
  • Ligands
  • Luciferases / metabolism
  • Matrix Attachment Region Binding Proteins / chemistry*
  • Matrix Attachment Region Binding Proteins / physiology*
  • Mice
  • Models, Genetic
  • NIH 3T3 Cells
  • Nuclear Matrix-Associated Proteins / chemistry*
  • Nuclear Matrix-Associated Proteins / physiology*
  • Plasmids / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA / chemistry
  • Receptors, Estrogen / chemistry*
  • Receptors, Estrogen / physiology*
  • Structure-Activity Relationship
  • Transcription, Genetic
  • Transcriptional Activation
  • Transfection
  • Two-Hybrid System Techniques

Substances

  • Enzyme Inhibitors
  • Histone Deacetylase Inhibitors
  • Histones
  • Ligands
  • Matrix Attachment Region Binding Proteins
  • Nuclear Matrix-Associated Proteins
  • Receptors, Estrogen
  • SAFB protein, human
  • SAFB2 protein, human
  • RNA
  • Luciferases