P53网络的控制机理与建模

P53 protein is a tumor suppressor, playing a key role as a factor in transcript network. In response to cell stress, P53 is activated and regulate the transcription of its downstream genes. the expression of these genes may regulate the original functions such as cell cycle checkpoint、apoptosis and DNA repair. The activity of P53 in cell is regulated through feedback loops involving its transcriptional targets Mdm2、COP1 and Pirh2. Oscillations of both P53 and Mdm2 indeed occur on exposure of various cell types to ionizing radiation. Such oscillations may allow cells to repair their DNA without risking the irreversible consequences of continuous excessive P53 activation.