What does the p53 gene regulate?
The TP53 gene provides instructions for making a protein called tumor protein p53 (or p53). This protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way.
How are p53 levels regulated?
p53 is regulated by an array of posttranslational modifications both during normal homeostasis and in stress-induced responses. More than 36 different amino acids within p53 have been shown to be modified in various biochemical and cell culture studies (Figure 1) (Kruse and Gu, 2008b).
Is p53 a regulatory gene?
The p53 protein regulates the transcription of many different genes in response to a wide variety of stress signals. Following DNA damage, p53 regulates key processes, including DNA repair, cell-cycle arrest, senescence and apoptosis, in order to suppress cancer.
Is p53 constitutively active?
In summary, we propose that increases in normally regulated p53, as in the ‘super p53’ mice, confer cancer protection without affecting aging, whereas, in contrast, constitutive levels of active p53 provide cancer protection but promote aging.
Is p53 a transcriptional activator?
p53 recognizes its DNA response elements by an elaborate mechanism involving a sequence-specific core DNA-binding domain and the regulatory C-terminal domain. p53 is solely a transcriptional activator, with gene repression downstream of p53 activation being indirect.
Is the p53 a direct activator of genes?
p53 target genes Recent genome-wide analyses and meta-analyses of genome-wide datasets of p53 DNA-binding and gene regulation show that p53 is a direct activator of a limited number of genes compared to the number of putative response-elements identified genome-wide. They also provide evidence that p53 is not a direct repressor of genes.
What is the function of the p53 protein?
p53 is a tumor suppressor protein that regulates cell division and prevents tumor formation by stopping cells with mutated or damaged DNA from dividing and signaling for them to undergo apoptosis through transcriptional regulation.
What happens to the p53 gene during growth arrest?
The growth arrest stops the progression of cell cycle, preventing replication of damaged DNA. During the growth arrest, p53 may activate the transcription of proteins involved in DNA repair. Apoptosis is the “last resort” to avoid proliferation of cells containing abnormal DNA.
What happens when p53 is no longer able to bind DNA?
A mutant p53 will no longer bind DNA in an effective way, and, as a consequence, the p21 protein will not be available to act as the “stop signal” for cell division.