User Visitor Login
English only
EPFL > FSV > BBP > Channelpedia
Ion channels
Logged in as a Visitor.

Insulator and silencer sequences in the imprinted region of human chromosome 11p15.5.

Minjie Du, Linda G Beatty, Wenjing Zhou, Jocelyne Lew, Christopher Schoenherr, Rosanna Weksberg, Paul D Sadowski

Hum. Mol. Genet., 2003 Aug 1 , 12, 1927-39

The imprinting of the genes on human chromosome 11p15.5 is thought to be controlled by two imprinting control regions located in two differentially methylated CpG islands upstream of the H19 gene (H19 DMR) and in intron 10 of the KCNQ1 gene (KvDMR). We have examined sequences in the human 11p15.5 genomic imprinted region for the presence of insulators and silencers using a position- and enhancer-dependent stable transfection assay. We have confirmed the existence of insulators in H19 DMR and discovered two novel insulators in the IGF2 gene. We have also found two novel silencer sequences; one is located in KvDMR, a region that is thought to contain the promoter for the KCNQ1OT1 transcript, and another is in the CDKN1C gene. We have demonstrated binding of CTCF protein in vitro to all the insulator and silencer sequences that we have detected. We discuss the differences in the regulation of imprinting controlled by the two imprinting control regions in chromosome 11p.