CHARACTERIZATION OF FMR1 PROMOTER ELEMENTS BY IN-VIVO - FOOTPRINTING ANALYSIS

Fragile X syndrome is associated with silencing of the FMR1 gene, We s tudied the transcriptional regulation, by analysis of the FMR1 promote r region for the presence of in vivo protein/DNA interactions and for cytosine methylation at the single-nucleotide level. Four protein-bind ing sites were present in the unmethylated promoter of the active FMR1 gene. In the methylated promoter of inactive genes no footprints were detected, and no evidence of active repression was found in the regio n investigated. We propose that the silencing of FMR1 gene transcripti on results from a lack of transcription-factor binding.