A protein that regulates the activity of other genes, p53 does act as a transcription factor. Why is the complexing domain of p53 so important to its function? The genes that p53 activates in turn control many functions, including the cell cycle and programmed cell death.Considering this, what is the importance of p53?
p53, also known as TP53 or tumor protein (EC :2.7. 1.37) is a gene that codes for a protein that regulates the cell cycle and hence functions as a tumor suppression. It is very important for cells in multicellular organisms to suppress cancer.
One may also ask, how does p53 detect DNA damage? After UV-induced DNA damage, activated p53 induces the expression of p48 and XPC, thus increasing the cell's capacity to locate and target DNA damage for repair.
Accordingly, how does p53 act as a tumor suppressor?
The p53 tumor suppressor protein. The p53 gene like the Rb gene, is a tumor suppressor gene, i.e., its activity stops the formation of tumors. In the cell, p53 protein binds DNA, which in turn stimulates another gene to produce a protein called p21 that interacts with a cell division-stimulating protein (cdk2).
What stage of the cell cycle does p53 work?
Major checkpoints occur at the G1 to S phase transition and at the G2 to M phase transitions. Cancer is a genetic disease that arises from defects in growth-promoting oncogenes and growth-suppressing tumor suppressor genes. The p53 tumor suppressor protein plays a role in both the G1/S phase and G2/M phase checkpoints.
How is p53 activated?
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 positive mean?
The p53 status was defined as negative in tumors with normal p53 sequence and negative IHC staining and defined as positive in tumors with either TP53 mutation or positive staining or both.How many p53 genes do humans have?
THE ROLE OF p53, p63, AND p73 IN REGULATING DEVELOPMENT OF THE ORGANISM. There is abundant evidence that the p53, 63, and 73 family of genes regulates the male and female germ-line production of gametes in response to stress, especially genomic damage.How would the loss of p53 activity affect a cell?
The cells would be smaller than normal. The microtubules that form the mitotic spindle grow out from the centrosome. How would the loss of p53 activity affect a cell? The G1/S checkpoint would be unregulated, DNA damage could accumulate,CDK activity would be unregulated.Where is p53 found?
The p53 protein is located in the nucleus of cells throughout the body, where it attaches (binds) directly to DNA.Is p53 an oncogene?
The standard classification used to define the various cancer genes confines tumor protein p53 (TP53) to the role of a tumor suppressor gene. However, it is now an indisputable fact that many p53 mutants act as oncogenic proteins.How was p53 discovered?
The Discovery of p53 Protein. The p53 protein was first identified in a study of the role of viruses in cancer through its ability to form a complex with viral tumor antigens. In the same year, an immunological study of cancer also found p53 due to its immunoreactivity with tumor antisera.What is the p53 pathway?
The p53 pathway is composed of a network of genes and their products that are targeted to respond to a variety of intrinsic and extrinsic stress signals that impact upon cellular homeostatic mechanisms that monitor DNA replication, chromosome segregation and cell division (Vogelstein et al., 2000).What cancers is p53 associated with?
Cancers Associated With p53 Gene MutationsBreast cancer: The TP53 gene is mutated in around 20 percent to 40% of breast cancers. Brain cancer (several types) Cholangiocarcinoma. Head and neck squamous cell cancer.Is p53 mutation hereditary?
LFS is a hereditary genetic condition. This means that the cancer risk can be passed from generation to generation in a family. This condition is most commonly caused by a mutation (alteration) in a gene called TP53, which is the genetic blueprint for a protein called p53.Why is p53 the guardian genome?
p53. As such, p53 has been described as "the guardian of the genome" because of its role in conserving stability by preventing genome mutation. Hence TP53 is classified as a tumor suppressor gene.Does p53 cause apoptosis?
Exposure to cellular stress can trigger the p53 tumor suppressor, a sequence-specific transcription factor, to induce cell growth arrest or apoptosis. However, p53 can also promote apoptosis by a transcription-independent mechanism under certain conditions.What happens when p53 is overexpressed?
p53 acts to initiate DNA repair allowing the cell to renter the cell cycle with maintained genetic integrity. Under extreme damage, p53 acts to initiate apoptosis in these cells where damage is beyond repair. For this to occur, p53 mediated machinery must be inhibited. p53 is mutated in roughly 50 percent of cancers.How many oncogenes are there?
More than 100 different oncogenes have been identified, but only some have been associated exclusively with human cancers.Is p53 a transcription factor?
The p53 tumor suppressor protein is widely known for its role as a transcription factor that regulates the expression of stress response genes and mediates a variety of anti-proliferative processes.What is p53 gene therapy?
p53 tumor suppressor gene therapy for cancer. Although multiple genes are involved in carcinogenesis, mutations of the p53 gene are the most frequent abnormality identified in human tumors. Preclinical studies both in vitro and in vivo have shown that restoring p53 function can induce apoptosis in cancer cells.How do normal cells become cancer cells?
Cancer is unchecked cell growth. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grows, it can develop into a tumor. 
Sarah Smith 
