P53 Signaling Pathway

It had been identified in the 1970s as a binding partner for the SV40 tumor virus oncoprotein large T antigen and an important target for tumor-igenic processes induced by DNA tumor viruses, research in the late 1980s and 1990s validated p53 as a tumor suppressor gene, as p53 mutations were found in up to 50% of human cancers. Mechanistically, p53 acts as a transcription factor that activates and represses a growing number of target genes implicated in cell cycle control. The task of p53 is to control the integrity and correctness of all processes in each individual cell and in the organism as a whole. Information about the state of ongoing events in the cell is gathered through multiple signaling pathways that convey signals modifying activities of p53. The strategy of p53 ensures genetic identity of cells and prevents the selection of abnormal cells. As an anti-cancer promotion agent, it can activate DNA repair proteins when DNA has sustained damage, induce growth arrest by holding the cell cycle at the G1/S regulation point on DNA damage recognition, or initiate apoptosis if DNA damage proves to be irreparable.