Cancer Protein Description
This report provides a detailed description of a selected cancer protein with information collected from various sources, including UniProt, the Wellcome Trust Sanger Institute’s Catalogue of Somatic Mutations in Cancer (COSMIC), and the Atlas of Genetics and Cytogenetics in Oncology and Haematology.
| Protein Name: | CD46 |
| Gene Name: | CD46 |
| Protein Full Name: | Membrane cofactor protein |
| Alias: | CD46 antigen; CD46 molecule, complement regulatory protein; MCP; MGC26544; MIC10; TLX; TRA2.10; Trophoblast leucocyte common antigen |
| Mass (Da): | 43747 |
| Number AA: | 392 |
| UniProt ID: | P1552 |
| Locus ID: | 4179 |
| COSMIC ID: | CD46 |
| Gene location on chromosome: | 1q32 |
| Cancer protein type: | OP |
| Effect of cancer mutation on protein: | GAIN |
| Effect of active protein on cancer: | PROMOTES |
| Number of cancer specimens: | 20074 |
| Percent of cancer specimens with mutations: | 0.28 |
| Normal role description: | CD46 is a type 1 membrane protein that is a regulator of the complement cascade via inactivating C3b and C4b; this action protects hosts cells from damage by complement. It is unclear if it affects oncogenesis, though host cell damage by complement is pro-inflamatory and inflammation has been positively correlated with oncogenesis -- particularaly inflammatory bowel disease and colon cancer; therefore, mutations in CD46 that lead to decreased activity could thusly make it an oncoprotein. |
| Commentary on involvement of protein in cancer: | Acts as a cofactor for complement factor I, a serine protease which protects autologous cells against complement-mediated injury by cleaving C3b and C4b deposited on host tissue. May be involved in the fusion of the spermatozoa with the oocyte during fertilization. Also acts as a costimulatory factor for T-cells which induces the differentiation of CD4+ into T-regulatory 1 cells. T-regulatory 1 cells suppress immune responses by secreting interleukin-10, and therefore are thought to prevent autoimmunity. A number of viral and bacterial pathogens seem to exploit this property and directly induce an immunosuppressive phenotype in T-cells by binding to CD46. Defects in CD46 are a cause of susceptibility to hemolytic uremic syndrome atypical type 2 (AHUS2) [MIM:612922]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype. Patients with CD46 mutations seem to have an overall better prognosis compared to patients carrying CFH mutations. |