Functional selectivity of recombinant mammalian SWI/SNF subunits

Genes Dev. 2000 Oct 1;14(19):2441-51. doi: 10.1101/gad.828000.

Abstract

The SWI/SNF family of chromatin-remodeling complexes plays a key role in facilitating the binding of specific transcription factors to nucleosomal DNA in diverse organisms from yeast to man. Yet the process by which SWI/SNF and other chromatin-remodeling complexes activate specific subsets of genes is poorly understood. We show that mammalian SWI/SNF regulates transcription from chromatin-assembled genes in a factor-specific manner in vitro. The DNA-binding domains (DBDs) of several zinc finger proteins, including EKLF, interact directly with SWI/SNF to generate DNase I hypersensitivity within the chromatin-assembled beta-globin promoter. Interestingly, we find that two SWI/SNF subunits (BRG1 and BAF155) are necessary and sufficient for targeted chromatin remodeling and transcriptional activation by EKLF in vitro. Remodeling is achieved with only the BRG1-BAF155 minimal complex and the EKLF zinc finger DBD, whereas transcription requires, in addition, an activation domain. In contrast, the BRG1-BAF155 complex does not interact or function with two unrelated transcription factors, TFE3 and NF-kappaB. We conclude that specific domains of certain transcription factors differentially target SWI/SNF complexes to chromatin in a gene-selective manner and that individual SWI/SNF subunits play unique roles in transcription factor-directed nucleosome remodeling.

Publication types

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

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Binding Sites
  • Chromatin / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • DNA Helicases*
  • DNA-Binding Proteins / metabolism
  • Erythroid-Specific DNA-Binding Factors
  • Globins / genetics
  • HIV-1 / genetics
  • Kruppel-Like Transcription Factors
  • Models, Genetic
  • NF-kappa B / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Nucleosomes / metabolism
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Subunits
  • Recombinant Proteins / metabolism
  • Transcription Factors / metabolism
  • Transcriptional Activation*
  • Zinc Fingers

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Erythroid-Specific DNA-Binding Factors
  • Kruppel-Like Transcription Factors
  • NF-kappa B
  • Nuclear Proteins
  • Nucleosomes
  • Protein Subunits
  • Recombinant Proteins
  • SMARCC1 protein, human
  • TFE3 protein, human
  • Transcription Factors
  • erythroid Kruppel-like factor
  • Globins
  • Adenosine Triphosphatases
  • DNA Helicases