The tumor suppressor gene p53 induces cell cycle arrest at:
G1/S check-point is controlled by p53 whereas G2/M check-point has both p53 dependent as well as independent mechanisms. p53 induces the synthesis of p21 which inhibits cyclin D/Cdk4. This results in stoppage of activation of Rb and cell cycle is arrested in G1/S phase. Fig:- Role of P53 in maintaining the integrity of the genome
G2-M phase
S-G2 phase
G1-S phase
G0 phase
General Concepts