Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein (CEBP)-like proteins: a DNA-binding and dimerization domain
This group is an uncharacterized subfamily of CEBP-like proteins. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate the cell cycle, differentiation, growth, survival, energy metabolism, innate and adaptive immunity, and inflammation, among others. They are also associated with cancer and viral disease. 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. Each possesses unique properties to regulate cell type-specific growth and differentiation. The sixth isoform, CEBPZ (zeta), lacks an intact DNA-binding domain and is excluded from this subfamily. 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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",