How is p53 activated by a DNA damage checkpoint?
How is p53 activated by a DNA damage checkpoint?
The tumour suppressor protein p53 is stabilised and activated in response to ionising radiation. This is known to depend on the kinase ATM; recent results suggest ATM acts via the downstream kinase Chk2/hCds1, which stabilises p53 at least in part by direct phosphorylation of residue serine 20.
What does p53 do in response to DNA damage?
Activation of p53 in response to DNA damage is associated with a rapid increase in its levels and with an increased ability of p53 to bind DNA and mediate transcriptional activation. This then leads to the activation of a number of genes whose products trigger cell-cycle arrest, apoptosis, or DNA repair.
What checkpoint does p53 regulate?
p53 plays a critical role both in the G1/S checkpoint, in which cells arrest prior to DNA replication and have a 2N content of DNA, and in the G2/M checkpoint, in which arrest occurs before mitosis and cells have a 4N content of DNA.
How is p53 inactivated?
The p53 protein is such a powerful tumor suppressor that it is inactivated in almost every tumor, through either mutations in the TP53 gene or deregulation of its associated pathways.
What does p53 when not mutated do when it finds damaged cells?
If the DNA can be repaired, p53 activates other genes to fix the damage. If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors.
What kind of gene is p53?
The p53 gene is a type of tumor suppressor gene. Also called TP53 gene and tumor protein p53 gene.
Where is the p53 gene located?
A gene that makes a protein that is found inside the nucleus of cells and plays a key role in controlling cell division and cell death.
What happens if p53 is mutated?
This altered p53 protein cannot regulate cell growth and division and is unable to trigger apoptosis in cells with mutated or damaged DNA. As a result, DNA damage can accumulate in cells. If such cells continue to divide in an uncontrolled way, they can lead to the formation of bladder cancer.