DNA methylation specifies chromosomal localization of MeCP2.
MeCP2 is a chromosomal protein that is concentrated in the centromeric heterochromatin of mouse cells. In vitro, the protein binds preferentially to DNA containing a single symmetrically methylated CpG. To find out whether the heterochromatic localization of MeCP2 depended on DNA methylation, we transiently expressed MeCP2-LacZ fusion proteins in cultured cells. Intact protein was targeted to heterochromatin in wild-type cells but was inefficiently localized in mutant cells with low levels of genomic DNA methylation. Deletions within MeCP2 showed that localization to heterochromatin required the 85-amino-acid methyl-CpG binding domain but not the remainder of the protein. Thus MeCP2 is a methyl-CpG-binding protein in vivo and is likely to be a major mediator of downstream consequences of DNA methylation.
Institute of Cell and Molecular Biology, University of Edinburgh, United Kingdom.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002868:Chromosomal Proteins, Non-Histone; D002874:Chromosome Mapping; D018899:CpG Islands; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D006570:Heterochromatin / Q000378:metabolism; D007763:Lac Operon; D051783:Methyl-CpG-Binding Protein 2; D008745:Methylation; D051379:Mice; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins
D002868:Chromosomal Proteins, Non-Histone; D017931:DNA Primers; D004268:DNA-Binding Proteins; D006570:Heterochromatin; C497393:Mecp2 protein, mouse; D051783:Methyl-CpG-Binding Protein 2; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D004247:DNA