The p53 tumor suppressor gene was initially identified as being essential for the DNA damage checkpoint, but it was subsequently found to have a broader function after cellular stress, such as oncogene activation or hypoxia. The p53 protein functions as a tetrameric transcription factor found at very low levels in normal unstressed cells. After stress, different pathways lead to post-translational modification of the protein and its stabilization. p53 database contains 16,000+ entries corresponding to TP53 mutations found in tumors, normal skin, and noncancerous diseases such as rheumatoid arthritis. The database also includes germline mutations found in Li-Fraumeni syndrome (LFS) and LFS-like syndrome. ... [Information of the supplier, modified]
Organs and organelles represent core biological systems in mammals, but the diversity in protein composition remains unclear. Here, we combine subcellular fractionation with exhaustive tandem mass spectrometry-based shotgun sequencing to examine the protein content of four major organellar compartments (cytosol, membranes [microsomes], mitochondria and nuclei) in six organs (brain, heart, kidney, liver, lung and placenta) of the laboratory mouse, Mus musculus. Using rigorous statistical filtering and machine-learning methods, the subcellular localization of 3274 of the 4768 proteins identified was determined with high-confidence, including 1503 previously uncharacterized factors, while tissue-selectivity was evaluated by comparison to previously reported mRNA expression patterns. This molecular compendium, fully accessible via a searchable web-browser interface, serves as a reliable reference of the expressed tissue and organelle proteomes of a leading model mammal. ... [Information of the supplier]
Protein phosphorylation is a post-translational modification that regulates an astonishing number of critical biological processes in multicellular organisms. Cellular protein phosphorylation is an enormously complex dynamic system: over 510 distinct protein kinases and 100 phosphoprotein phosphatases are encoded in the human genome, and upwards of 40% of cellular proteins may be phosphorylated during some stage of growth and differentiation. Many proteins are multiply phosphorylated on scores of sites, making it likely that there are minimally 100,000 distinct phosphorylation sites in the mammalian proteome. It is the intention of the scientists who are designing and implementing PhosphoSite to provide an accurate and comprehensive source of information about mammalian protein phosphorylation sites. Our goal is to identify and organize information about all in vivo phosphorylation sites in human and mouse proteomes and to provide information and resources that will facilitate phosphorylation research. PhosphoSite is a curated, sequence-oriented protein database dedicated to in vivo phosphorylation sites. Information in PhosphoSite version 1.0 includes: (a) The phosphorylated residue and its surrounding sequence. We consider this information to be the central, organizing feature of PhosphoSite. (b) Orthologous sites in other species; this should assist investigators in determining if a phosphorylation site in species A might also be phosphorylated in species B. (c) The location within domains and motifs; this should assist investigators in inferring possible biological functions of phosphorylation sites. (d) Links to other online resources including the Alliance for Cell Signaling, the Protein Kinase Resource, and Scansite. Scansite predicts likely sites for protein phosphorylation by particular kinases and likely sites for interaction with other signaling proteins. This information, based upon vitro data, will be highly complimentary to that provided by PhosphoSite. (e) Literature references which demonstrate the in vivo nature and significance of the phosphorylation site. (...) Curated information will come from literature reports as well as from high-throughput phosphosite discovery programs. Information extracted from the public domain will be freely available for educational users. Proprietary information from phosphorylation site discovery programs may be available on a subscription basis. Corporations will need to pay a reasonable yearly fee to legally access PhosphoSite. ... [Information of the supplier, modified]
