A distinct DNA-methylation boundary in the 5'- upstream sequence of the FMR1 promoter binds nuclear proteins and is lost in fragile X syndrome.

ABSTRACT: We have discovered a distinct DNA-methylation boundary at a site between 650 and 800 nucleotides upstream of the CGG repeat in the first exon of the human FMR1 gene. This boundary, identified by bisulfite sequencing, is present in all human cell lines and cell types, irrespective of age, gender, and developmental stage. The same boundary is found also in different mouse tissues, although sequence homology between human and mouse in this region is only 46.7%. This boundary sequence, in both the unmethylated and the CpG-methylated modes, binds specifically to nuclear proteins from human cells. We interpret this boundary as carrying a specific chromatin structure that delineates a hypermethylated area in the genome from the unmethylated FMR1 promoter and protecting it from the spreading of DN

SUBMITTER: Naumann A 

PROVIDER: S-EPMC2775827 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature