Structure CREB

general structure of creb protein.

creb proteins activated phosphorylation various kinases, including pka, , ca/calmodulin-dependent protein kinases on serine 133 residue. when activated, creb protein recruits other transcriptional coactivators bind cre promoter 5’ upstream region. hydrophobic leucine amino acids located along inner edge of alpha helix. these leucine residues tightly bind leucine residues of creb protein forming dimer. chain of leucine residues forms leucine zipper motif. protein has magnesium ion facilitates binding dna.

camp response element

the camp response element (cre) response element creb contains highly conserved nucleotide sequence, 5 -tgacgtca-3’. cre sites typically

found upstream of genes, within promoter or enhancer regions. there approximately 750,000 palindromic , half-site cres in human genome. however, majority of these sites remain unbound due cytosine methylation physically obstructs protein binding.