| proteins | Nitrogenous organic compounds, containing more than about 100 amino acid residues, molecular weight 8,000-200,000, in vegetable and animal matter. Proteins yield amino acids on hydrolysis and are foods assimilated as amino acids and reconstructed in the protoplasm. (12 Dec 1998) |
|---|---|
| proto-oncogene proteins | Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity. (12 Dec 1998) |
| proto-oncogene proteins c-abl | Membrane proteins encoded by the c-abl genes. They exhibit tyrosine kinase activity and play a role in normal haematopoiesis especially of the myeloid lineage. Oncogenic transformation of c-abl arises when specific n-terminal amino acids are deleted, releasing the kinase from negative regulation. (12 Dec 1998) |
| proto-oncogene proteins c-bcl-2 | Membrane proteins encoded by the bcl-2 genes and serving as a potent inhibitor of cell death by apoptosis. The proteins are found on mitochondrial, microsomal, and nuclear membrane sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma. (12 Dec 1998) |
| proto-oncogene proteins c-erbb-2 | Cellular proteins in the epidermal growth factor receptor family encoded by the c-erbb genes. These proteins are overexpressed in a significant portion of adenocarcinomas found at various sites, especially in the breast. Gene amplification appears to be the predominant method leading to overexpression. (12 Dec 1998) |
| proto-oncogene proteins c-fos | Cellular DNA-binding proteins encoded by the c-fos genes (genes, fos). They are involved in growth-related transcriptional control. C-fos combines with c-jun (proto-oncogene proteins c-jun) to form a c-fos/c-jun heterodimer (transcription factor ap-1) that binds to the tre (tpa-responsive element) in promoters of certain genes. (12 Dec 1998) |
| proto-oncogene proteins c-jun | Cellular DNA-binding proteins encoded by the c-jun genes (genes, jun). They are involved in growth-related transcriptional control. There appear to be three distinct functions: dimerization (with c-fos), DNA-binding, and transcriptional activation. Oncogenic transformation can take place by constitutive expression of c-jun. (12 Dec 1998) |
| proto-oncogene proteins c-kit | Tyrosine kinase membrane receptors which are the natural ligands for mast cell growth factor (steel factor). This interaction is crucial for the development of haematopoietic, gonadal, and pigment stem cells. (12 Dec 1998) |
| proto-oncogene proteins c-met | <enzyme> A transmembrane tyrosine kinase that is the receptor for hepatocyte growth factor (scatter factor). It consists of an extracellular alpha chain which is disulfide linked to the transmembrane beta chain. The cytoplasmic portion contains the catalytic domain and critical sites for the regulation of kinase activity. Registry number: EC 2.7.11.- (12 Dec 1998) |
| proto-oncogene proteins c-mos | Cellular proteins encoded by the c-mos genes (genes, mos). They function in the cell cycle to maintain maturation-promoting factor in the active state and have protein-serine/threonine kinase activity. Oncogenic transformation can take place when c-mos proteins are expressed at the wrong time. (12 Dec 1998) |
| proto-oncogene proteins c-myc | Cellular DNA-binding proteins encoded by the c-myc genes. They are normally involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Elevated and deregulated (constitutive) expression of c-myc proteins can cause tumourigenesis. (12 Dec 1998) |
| proto-oncogene proteins c-raf | <enzyme> A class of serine-threonine kinases involved in cellular signal transduction. Included in this class are the proto-oncogene proteins mil and raf. Raf is a component of a signal transduction pathway leading to increased gene expression through the c-jun DNA binding site, ap1. Registry number: EC 2.7.10.- (12 Dec 1998) |
| protozoan proteins | Proteins found in any species of protozoan. (12 Dec 1998) |
| prpc proteins | Normal cellular isoform of prion proteins (prions) encoded by a chromosomal gene and found in normal and scrapie-infected brain tissue, and other normal tissue. Prpc are protease-sensitive proteins whose function is unknown. Posttranslational modification of prpc into prpsc leads to infectivity. (12 Dec 1998) |
| prpsc proteins | Abnormal isoform of prion proteins (prions) resulting from a posttranslational modification of the cellular prion protein (prpc proteins). Prpsc are disease-specific proteins seen in certain human and animal neurodegenerative diseases (prion diseases). (12 Dec 1998) |