The Ski protein family is required for MeCP2-mediated transcriptional repression.
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.
Kokura
K
K
Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, Ibaraki 305-0074, Japan.
Kaul
S C
SC
Wadhwa
R
R
Nomura
T
T
Khan
M M
MM
Shinagawa
T
T
Yasukawa
T
T
Colmenares
C
C
Ishii
S
S
D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D018899:CpG Islands; D019175:DNA Methylation; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D005982:Glutathione Transferase / Q000378:metabolism; D006570:Heterochromatin / Q000737:chemistry; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2; D005810:Multigene Family; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000737:chemistry* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012097:Repressor Proteins; D014158:Transcription, Genetic
D002868:Chromosomal Proteins, Non-Histone; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006570:Heterochromatin; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C512653:Ski protein, mouse; C060614:SKI protein, human; D005982:Glutathione Transferase