Somatostatin receptor 2

Somatostatin receptor type 2 is a protein that in humans is encoded by the SSTR2 gene. The SSTR2 gene is located on chromosome 17 on the long arm in position 25.1 in humans. It is also found in most other vertebrates. The somatostatin receptor 2 (SSTR2), which belongs to the G-protein coupled receptor family, is a protein which is most highly expressed in the pancreas (both alpha- and beta-cells), but also in other tissues such as the cerebrum and kidney and in lower amount in the jejunum, colon and liver. In the pancreas, after binding to somatostatin, it inhibits the secretion of peptide hormones from pancreatic islets. During development, it stimulates neuronal migration and axon outgrowth. The somatostatin receptor 2 is expressed in most tumors. Patients with neuroendocrine tumors that over-express the somatostatin receptor 2 have an improved prognosis. The over expression of SSTR2 in tumors can be exploited to selectively deliver radio-peptides to tumors to either detect or destroy them. Somatostatin receptor 2 also has the ability to stimulate apoptosis in many cells including cancer cells. The somatostatin receptor 2 is also being looked at as a possible target in cancer treatment for its ability to inhibit tumor growth. The gene for somatostatin receptor 2, SSTR2 for short, is responsible for making a receptor for the signalling peptide, somatostatin (SST). Production occurs in the central nervous system, especially the hypothalamus, as well as the digestive system, and pancreas. SSTR2 is a receptor for somatostatin-14 and -28 respectively. The numbers 14 and 28 represent the amount of amino acids in each protein sequence. All somatostatin receptors including SSTR2 may have different specific functions, but all fall under the same receptor super family, the G-protein binding family and all of which are a major inhibitor for other hormones. For all somatostatin inhibitors, somatostatin-14 and -28 work by binding to the receptor with the help of a G-protein. This inhibits adenylyl cyclase and calcium channels.