DDIT3/CHOP/GADD153 [H5]

DDIT3 (DNA-damage-inducible transcript 3, CHOP, GADD153) is a member of the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors. It is a small nuclear protein that is capable of forming heterodimers with other C/EBP members such as C/EBP and LAP (liver activator protein), and preventing their DNA binding and function of C/EBP to classical binding sites. Inversely, the C/EBP GADD153 heterodimer gains binding activity to other non classical C/EBP stress related targets. Under normal cellular conditions this protein is not expressed in detectable levels, but is highly unregulated during times of cellular/ER stress. Examples of DDIT3 inducing stress include: treatment with tunicamycin, nutrient starvation and reducing agents that interfere with the calcium flux across the ER membrane. The protein is implicated in adipogenesis and erythropoiesis, is activated by endoplasmic reticulum stress, and promotes apoptosis.