Code:71-115
p53 mutants are found in more than half of human cancers and are considered as the most important human cancer related gene. p53 is detected at 53kD position by electrophoresis and is composed of 393 amino acids. In the unstressed normal cells the p53 level is low and it is inactive. However with stress especially with DNA damage it is activated to promote arrest of cell cycle and repair of DNA damage or induction of apoptosis. The functions of p53 are regulated by phosphorylation of serine and threonine and acetylation of lysine at various sites in the molecule. Among the phosphorylation sites Ser46 is phosphorylated when DNA damage is so severe as to become unrepairable which leads to apoptosis by activating transcription of proapoptotic genes such as p53AIPI As to the kinase of phosphorylation of Ser46 involvement of DYRK2 and ATM have been implicated.
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