What is a p53 isoform?
p53 isoform proteins thus contain distinct protein domains. They are expressed in normal human tissues but are abnormally expressed in a wide range of cancer types. We have recently reported that p53 isoform expression is associated with breast cancer prognosis, suggesting that they play a role in carcinogenesis.
What is the function of a p53?
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. Mutations (changes) in the p53 gene may cause cancer cells to grow and spread in the body.
What is the transcription of p53?
p53 is a DNA-binding transcription factor that activates genes responsible for a cell-cycle checkpoint or apoptosis after exposure to ionizing radiation, UV light, or other DNA-damaging agents [1–3]. The p53 protein is induced both in terms of its abundance and its activity in response to DNA damage.
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.
What is the molecular weight of p53?
p53 is well known for its key role as a tumor suppressor protein. It is 393 amino acids (aa) in length with a predicted molecular weight of 44 kDa.
What is isoform chemistry?
: any of two or more functionally similar proteins that have a similar but not an identical amino acid sequence.
Is p53 a repressor?
p53 is the Ultimate Direct Activator, not Really a Direct Repressor. The fact that p53 regulates a vast gene expression program that involves both mRNA upregulation and downregulation is undisputed. However, the extent to which p53 functions as a direct transcriptional repressor has long been debated.
Does p53 activate MDM2?
In normal cells, p53 is kept at low levels by murine double minute 2 (MDM2), an ubiquitin ligase. MDM2 and p53 form a negative-feedback loop, in which p53 induces the expression of MDM2, which in turn promotes the degradation of p53 and quenches cellular p53 activity.
What is the structure of p53?
The human p53 protein consists of 393 amino acids and contains four major functional domains. At the N-terminus is a transcriptional activation domain (amino acids 1 – 42) and within the central part of p53 is the sequence-specific DNA-binding domain (amino acids 102 – 292).
Which is an isoform of the canonical p53 protein?
By convention, TAp53alpha corresponds to the canonical p53 protein. In addition to these isoforms, deltap53 has been described that lacks residues from center of exon 7 to center of exon 9. See illustration below. Current knowledge on the role and activities of these isoforms is still limited.
What is the role of p53 in cancer?
1 University of Dundee, Ninewells Hospital, Centre for Oncology and Molecular Medicine, Inserm-European Associated Laboratory, Inserm U858, CR-UK Cell Transformation Research Group, Dundee, United Kingdom. p53 is a transcription factor with a key role in the maintenance of genetic stability and therefore preventing cancer formation.
Are there any human isoforms that use alternative splicing?
Several p53 human isoforms have been characterized that are produced by alternative splicing, use of alternative translation site or alternative promoter (see Joruiz & Bourdon, 2016; Marcel et al., 2011 ).
Where can I find the TP53 gene annotations?
In the IARC TP53 Database, all annotations and data are in relation to the full-lenght protein (TA isoform). New annotations have been introduced on the predicted impact of TP53 gene mutations on the protein status of the different isoforms (see here ).