Interactions Between HMG proteins and 5'-Flanking cis-Acting Elements of Human epsilon-Globin Gene

HMG proteins are abundant chromosomal non-histone proteins. It has been shown that HMG proteins play important roles in the structure and function of chromatin. In this work, the binding of HMG proteins to the 5'-Flanking positive and negative regulatory elements of human epsilon-globin Gene gene has been examined by gel mobility shift and DNaseI footprinting assays. Our results demonstrated that HMG proteins 1/2 could bind not only to both positive regulatory elements(-535~-453 bp and -446~-419 bp) but also to the promoter (-177~+1bp) of this gene; however, HMG proteins 14/17 could not bind to those regulatory elements. On the other hand, we also observed that HMG proteins 14/17 could bind to the 5'-flanding silencer(-392~-177 bp) of human epsilon-globin gene, and HMG proteins 1/2 could not bind to that silencer. Our results suggest that HMG proteins might play a critical role in the regulation of the human epsilon-globin gene expression through DNA-protein interactions.