Allele-specific methylation of a functional CTCF binding site upstream of MEG3 in the human imprinted domain of 14q32
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The gene MEG3 is located in the imprinted human chromosomal region on 14q32. Imprinting of a structurally homologous region IGF2/H19 on 11p15 is mediated through cytosine methylation-controlled binding of the protein CTCF to target sites upstream of H19. We identified five new CTCF binding sites around the promoter of MEG3. Using an electrophoretic mobility shift assay, we showed that these sites bind CTCF in vitro. Using one of these sites, chromatin immunoprecipitation (ChIP) analysis confirmed CTCF binding in-vivo, and differential allele-specific methylation was demonstrated in seven individuals with either maternal or paternal uniparental disomy 14 (UPD14). The site was unmethylated on the maternally inherited chromosomes 14 and methylated on the paternally inherited chromosomes 14, suggesting parent-specific methylation of sequences upstream of MEG3. We speculate that this CTCF-binding region may provide a mechanism for the transcriptional regulation of MEG3 and DLK1.
Key wordsepigenetics imprinting methylation protein binding sites UPD
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- Sasaki H, Ishihara K, Kato R (2000) Mechanisms of Igf2/H19 imprinting: DNA methylation, chromatin and long-distance gene regulation. J Biochem (Tokyo) 127: 711–715.Google Scholar
- Towner DR, Shaffer LG, Yang SP, Walgenbach DD (2001b) Confined placental mosaicism for trisomy 14 and maternal uniparental disomy in association with elevated second trimester maternal serum human chorionic gonadotrophin and third trimester fetal growth restriction. Prenat Diagn 21: 395–398.CrossRefPubMedGoogle Scholar