?
Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein gamma (CEBPG): a DNA-binding and dimerization domain CEBPG is an important regulator of cellular senescence; mouse embryonic fibroblasts deficient of CEBPG proliferated poorly, entered senescence prematurely, and expressed elevated levels of proinflammatory genes. It is also the primary transcription factor that regulates antioxidant and DNA repair transcripts in normal bronchial epithelial cells. In a subset of AML patients with CEBPA hypermethylation, CEBPG is significantly overexpressed. CEBPG is the shortest CEBP protein and it lacks a transactivation domain. It acts as a regulator and buffering reservoir against the transcriptional activities of other CEBP proteins. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.
|