Growth Arrest And DNA Damage Inducible Protein Alpha (GADD45a)

GADD45a is a member of a group of genes whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents. The protein encoded by this gene responds to environmental stresses by mediating activation of the p38/JNK pathway via MTK1/MEKK4 kinase. The DNA damage-induced transcription of this gene is mediated by both p53-dependent and -independent mechanisms.

GADD45 is the only known x-ray responsive gene whose induction is not mediated by PKC. Sequence analysis of human and hamster cDNA clones demonstrated that the gene has been highly conserved and encodes a novel 165-amino acid polypeptide that is 96% identical in the 2 species.