Sin3: a flexible regulator of global gene expression and genome stability

Curr Genet. 2005 Jan;47(1):1-17. doi: 10.1007/s00294-004-0541-5. Epub 2004 Nov 23.


SIN3 was first identified genetically as a global regulator of transcription. Sin3 is a large protein composed mainly of protein-interaction domains, whose function is to provide structural support for a heterogeneous Sin3/histone deacetylase (HDAC) complex. The core Sin3/HDAC complex is conserved from yeast to man and consists of eight proteins. In addition to HDACs, Sin3 can sequester other enzymatic functions, including nucleosome remodeling, DNA methylation, N-acetylglucoseamine transferase activity, and histone methylation. Since the Sin3/HDAC complex lacks any DNA-binding activity, it must be targeted to gene promoters by interacting with DNA-binding proteins. Although most research on Sin3 has focused on its role as a corepressor, mounting evidence suggests that Sin3 can also positively regulate transcription. Furthermore, Sin3 is key to the propagation of epigenetically silenced domains and is required for centromere function. Thus, Sin3 provides a platform to deliver multiple combinations modifications to the chromatin, using both sequence-specific and sequence-independent mechanisms.

Publication types

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

MeSH terms

  • Chromatin
  • DNA Methylation
  • Gene Expression Regulation*
  • Genomic Instability
  • Histone Deacetylases
  • Humans
  • Repressor Proteins / pharmacology*
  • Saccharomyces cerevisiae Proteins / pharmacology*
  • Transcription Factors / pharmacology*


  • Chromatin
  • Repressor Proteins
  • SIN3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Histone Deacetylases