Effects of Rett syndrome mutations of the methyl-CpG binding domain of the transcriptional repressor MeCP2 on selectivity for association with methylated DNA.
We have investigated the properties of mutant forms of the methyl-CpG binding transcriptional repressor MeCP2 associated with Rett syndrome, a childhood neurodevelopmental disorder. We find that four Rett syndrome mutations at known sites within the methyl-CpG binding domain (MBD) impair binding to methylated DNA, but have little effect on nonspecific interactions with unmethylated DNA. Three of these mutations (R106W, R133C, and F155S) have their binding affinities for methylated DNA reduced more than 100-fold; this is consistent with the hypothesis that impaired selectivity for methylated DNA of mutant MeCP2 contributes to Rett syndrome. However, a fourth mutant, T158M, has its binding affinity for methylated DNA reduced only 2-fold, indicative either of additional distinct regulatory functions associated with the MBD or of an exquisite sensitivity of developing neurons to the selective association of MeCP2 with methylated DNA.
Ballestar
E
E
National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-5431, USA.
Yusufzai
T M
TM
Wolffe
A P
AP
D000595:Amino Acid Sequence; D002868:Chromosomal Proteins, Non-Histone; D002942:Circular Dichroism; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D015342:DNA Probes / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry; D012097:Repressor Proteins / Q000235:genetics*; D015518:Rett Syndrome / Q000235:genetics*; D016415:Sequence Alignment
D002868:Chromosomal Proteins, Non-Histone; D015342:DNA Probes; D004268:DNA-Binding Proteins; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D011994:Recombinant Proteins; D012097:Repressor Proteins