p53 ( also known as protein 53 or tumor protein 53 ), is a tumor suppressor protein that in humans is encoded by the TP53 gene.

In humans, p53 is encoded by the TP53 gene located on the short arm of chromosome 17 ( 17p13. 1 ).

The gene spans 20 kb, with a non-coding exon 1 and a very long first intron of 10 kb. The coding sequence contains five regions showing a high degree of conservation in vertebrates, predominantly in exons 2, 5, 6, 7 and 8, but the sequences found in invertebrates show only distant resemblance to mammalian TP53.

( Italics are used to denote the TP53 gene name and distinguish it from the protein it encodes.

If the TP53 gene is damaged, tumor suppression is severely reduced.

People who inherit only one functional copy of the TP53 gene will most likely develop tumors in early adulthood, a disease known as Li-Fraumeni syndrome.

The TP53 gene can also be damaged in cells by mutagens ( chemicals, radiation, or viruses ), increasing the likelihood that the cell will begin decontrolled division.

More than 50 percent of human tumors contain a mutation or deletion of the TP53 gene.

Certain pathogens can also affect the p53 protein that the TP53 gene expresses.

The human TP53 gene was cloned in 1984 and the full length clone in 1985.

Another important tumor suppressor is the p53 tumor-suppressor protein encoded by the TP53 gene.

The p53 protein, produced by the TP53 gene, normally monitors cell division and kills cells if they have Wnt pathway defects.

Eventually, a cell line acquires a mutation in the TP53 gene and transforms the tissue from an adenoma into an invasive carcinoma.

Analysis of 316 high-grade serous ovarian adenocarcinomas found that the TP53 gene was mutated in 96 % of cases.

Ninety-seven percent of tumors in the ‘ classical ’ subtype carry extra copies of the Epidermal growth factor receptor ( EGFR ) gene, and most have higher than normal expression of Epidermal growth factor receptor ( EGFR ), whereas the gene TP53, which is often mutated in glioblastoma, is rarely mutated in this subtype.

In contrast, the proneural subtype often has high rates of alterations in TP53, and in PDGFRA, the gene encoding a-type platelet-derived growth factor receptor, and in IDHl, the gene encoding isocitrate dehydrogenase-1.

Meta-analyses from 2011 found no significant associations between TP53 codon 72 polymorphisms and both colorectal cancer risk and endometrial cancer risk.

* The George Pantziarka TP53 Trust A support group from the UK for sufferers of Li-Fraumeni Syndrome or other TP53-related disorders

A 2011 study found that TP53 codon 72 polymorphism was associated with an increased risk of lung cancer.

Warren Maltzman, of the Waksman Institute of Rutgers University first demonstrated that TP53 was responsive to DNA damage in the form of ultraviolet radiation.

In a series of publications in 1991-92, Michael Kastan, Johns Hopkins University, reported that TP53 was a critical part of a signal transduction pathway that helped cells respond to DNA damage.

median survival was 71 months, 1p intact with TP53 mutation

* IARC TP53 Somatic Mutations database maintained at IARC, Lyon, by Magali Olivier

A study of Arab women found that proline homozygosity at TP53 codon 72 is associated with a decreased risk for breast cancer.

One study suggested that TP53 codon 72 polymorphisms, MDM2 SNP309, and A2164G may collectively be associated with non-oropharyngeal cancer susceptibility and that MDM2 SNP309 in combination with TP53 codon 72 may accelerate the development of non-oropharyngeal cancer in women.

Wilson's disease is an autosomal-recessive gene disorder whereby an alteration of the ATP7B gene results in an inability to properly excrete copper from the body.

It is now appreciated that most or all gene loci are highly polymorphic, with multiple alleles, whose frequencies vary from population to population, and that a great deal of genetic variation is hidden in the form of alleles that do not produce obvious phenotypic differences.

In order to create a tumor necrosis factor ( TNF ) knockout, an exon containing the nucleotides 3704-5364 was removed from the gene.

Albinism results from inheritance of recessive gene alleles and is known to affect all vertebrates, including humans.

All of these techniques are extremely noise-prone and / or subject to bias in the biological measurement, and a major research area in computational biology involves developing statistical tools to separate signal from noise in high-throughput gene expression studies.

Expression data can be used to infer gene regulation: one might compare microarray data from a wide variety of states of an organism to form hypotheses about the genes involved in each state.

One of the latest developments is the identification of a plant gene, At-DBF2, from Arabidopsis thaliana, a tiny weed that is often used for plant research because it is very easy to grow and its genetic code is well mapped out.

Expressing the toxin was achieved by inserting a gene from the microorganism Bacillus thuringiensis into the corn genome.

Since the gene is recessive, all offspring will be heterozygous, and the offspring from that mating will not be resistant to Bt and therefore no longer a threat.

The theory asserts that all currently living organisms on Earth share a common genetic heritage with each being the descendant from a single original species, though the suggestion of substantial horizontal gene transfer during early evolution has led to questions about monophyly of life.

When scientists transfer a gene from one cell into another cell in order to express the new genetic material as a protein in the recipient cell, the cDNA will be added to the recipient ( rather than the entire gene ), because the DNA for an entire gene may include DNA that does not code for the protein or that interrupts the coding sequence of the protein ( e. g., introns ).

A protein is created by ribosomes that " read " RNA that is encoded by codons in the gene and assemble the requisite amino acid combination from the genetic instruction, in a process known as translation.

The DCA excluded the wording " double-dapple " from the standard in 2007 and now strictly use the wording " dapple " as the double dapple gene is commonly responsible for blindness and deafness.

While the Darwin Awards are named after Charles Darwin, due to his theory of natural selection, there is no evidence that the stories depicted actually represent the removal of " judgement impairment genes " from the gene pool.

The evolution of this group of viruses appears to be complex with gene having been gained from multiple sources.

Histones, gene regulatory proteins, DNA and RNA polymerases, and other substances essential for nuclear activities must be imported from the cytoplasm.

Furthermore, transcripts made from the same gene may not have the same exon structure, since parts of the mRNA could be removed by the process of alternative splicing.

Evidence from sequencing mitochondrial DNA indicated that no significant gene flow occurred between H. neanderthalensis and H. sapiens, and, therefore, the two were separate species that shared a common ancestor about 660, 000 years ago.

Genetics deals with the molecular structure and function of genes, gene behavior in context of a cell or organism ( e. g. dominance and epigenetics ), patterns of inheritance from parent to offspring, and gene distribution, variation and change in populations, such as through Genome-Wide Association Studies.

When genes are inserted, they usually come from a different species, which is a form of horizontal gene transfer.

To do this artificially may require attaching the genes to a virus or just physically inserting the extra DNA into the nucleus of the intended host with a very small syringe, or with very small particles fired from a gene gun.