Question

A. You have your own p53 gene sequenced and notice that you have 1 mutation in the portion of the protein that binds to DNA. You also notice that the mutation is a silent mutation. Are you at a higher risk then someone with wild type p53 to develop p53 related cancers? Explain your answer in 1 sentence.

Answer 1

Answer:

p53, also known as TP53 or tumor protein, 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. p53 has been described as " the guardian of the genome ", referring to its role in conserving stability by preventing genome mutation. The name is due to molecular mass; it is in the 53 kilodalton fraction of cell proteins.

Inactivation of the p53 tumor suppressor is a frequent event in tumorigenesis. In most cases, the p53 gene is mutated, giving rise to a stable mutant protein whose accumulation is regarded as a hallmark of cancer cells. Mutant p53 proteins not only lose their tumor suppressive activities but often gain additional oncogenic functions that endow cells with growth and survival advantages. Interestingly, mutations in the p53 gene were shown to occur at different phases of the multistep process of malignant transformation, thus contributing differentially to tumor initiation, promotion, aggressiveness, and metastasis.

The p53 tumor suppressor protein, encoded by the TP53 gene, lies at the center of an elaborated circuit controlling cell proliferation and interconnecting with many cellular functions. In response to various forms of stress, p53 is activated and accumulates in the nucleus, where it regulates the transcription of numerous target genes using specific DNA response elements. From the p53 activation, several biological responses occur including apoptosis, cell cycle arrest, DNA repair, differentiation or senescence. The nature of the p53-induced response depends on the type of stress and cell/tissue in which it occurs. Beyond its nuclear role, p53 regulates some mitochondrial functions. Thus, p53 is the archetype of a truly multifunctional protein, in which a small number of structural domains is specifically involved in vast arrays of complex interactions with various species (DNA, RNA, proteins and cell metabolites).