The most well-documented biochemical property of p53 is its ability to transcriptionally activate genes. Many of the genes which are activated by p53 expression prior to the onset of apoptosis are predicted to encode proteins which could generate or respond to oxidative stress, including one that is implicated in apoptosis within plant meristems. p53 may result in apoptosis through a three-step process: (I) the transcriptional induction of specific redox-related genes; (ii) the formation of reactive oxygen species (ROS); and (iii) the oxidative degradation of mitochondrial components, rapidly leading to cell death. Transcription of other genes is decreased by p53. Examination of the level of transcription of p53-induced or, -repressed genes can be used to determine p53 status, to diagnose cancer, and to evaluate cytotoxicity or carcinogenicity of a test agent.
展开▼
