The Ski protein family is required for MeCP2-mediated transcriptional repression

J Biol Chem. 2001 Sep 7;276(36):34115-21. doi: 10.1074/jbc.M105747200. Epub 2001 Jul 5.

Abstract

DNA methylation is essential for development in the mouse and plays an important role in inactivation of the X chromosome and genomic imprinting. MeCP2 is the founder member of a family of methyl-CpG-binding proteins. MeCP2 directly binds to the co-repressor mSin3, which interacts with class I histone deacetylase, recruiting them to methyl-CpG regions to suppress transcription. Here, we report that MeCP2 directly binds to two co-repressors, c-Ski and N-CoR, in addition to mSin3A, and that the c-Ski, which is encoded by the c-ski proto-onocogene, is required for MeCP2-mediated transcriptional repression. The two regions of c-Ski, including the C-terminal coiled-coil region, interact with the transcriptional repression domain in the center of the MeCP2 molecule. The immunostaining signals for c-Ski and MeCP2 overlap in the nuclear heterochromatin region, suggesting the co-localization of the two proteins. The degree of transcriptional repression mediated by a Gal4-MeCP2 fusion protein was abrogated by overexpression of the putative dominant negative form of c-Ski. Furthermore, injection of antibodies against c-Ski and Sno almost completely abolished the transcriptional repression mediated by the Gal4-MeCP2 fusion protein. These results suggest that the ski gene family is involved in methyl CpG-mediated transcriptional repression.

Publication types

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

MeSH terms

  • Blotting, Western
  • Cell Line
  • Cell Nucleus / metabolism
  • Chromosomal Proteins, Non-Histone*
  • CpG Islands
  • DNA Methylation
  • DNA, Complementary / metabolism
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation*
  • Genes, Dominant
  • Glutathione Transferase / metabolism
  • Heterochromatin / chemistry
  • Humans
  • Methyl-CpG-Binding Protein 2
  • Multigene Family
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / chemistry*
  • Proto-Oncogene Proteins / metabolism
  • Recombinant Fusion Proteins / chemistry
  • Repressor Proteins*
  • Transcription, Genetic*

Substances

  • Chromosomal Proteins, Non-Histone
  • DNA, Complementary
  • DNA-Binding Proteins
  • Heterochromatin
  • MECP2 protein, human
  • Methyl-CpG-Binding Protein 2
  • Proto-Oncogene Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Ski protein, mouse
  • SKI protein, human
  • Glutathione Transferase