Recombinant Human Somatostatin receptor type 2 (SSTR2) Protein

Function

Receptor for somatostatin-14 and -28. This receptor is coupled via pertussis toxin sensitive G proteins to inhibition of adenylyl cyclase. In addition it stimulates phosphotyrosine phosphatase and PLC via pertussis toxin insensitive as well as sensitive G proteins. Inhibits calcium entry by suppressing voltage-dependent calcium channels. Acts as the functionally dominant somatostatin receptor in pancreatic alpha- and beta-cells where it mediates the inhibitory effect of somatostatin-14 on hormone secretion. Inhibits cell growth through enhancement of MAPK1 and MAPK2 phosphorylation and subsequent up-regulation of CDKN1B. Stimulates neuronal migration and axon outgrowth and may participate in neuron development and maturation during brain development. Mediates negative regulation of insulin receptor signaling through PTPN6. Inactivates SSTR3 receptor function following heterodimerization

Subcellular Location

Cell membrane (Multi-pass membrane protein); Cytoplasm

Tissue Specificity

Expressed in both pancreatic alpha- and beta-cells (at protein level). Expressed at higher levels in the pancreas than other somatostatin receptors. Also expressed in the cerebrum and kidney and, in lesser amounts, in the jejunum, colon and liver. In the developing nervous system, expressed in the cortex where it is located in the preplate at early stages and is enriched in the outer part of the germinal zone at later stages. In the cerebellum, expressed in the deep part of the external granular layer at gestational week 19. This pattern persists until birth but disappears at adulthood

Subunit

Homodimer and heterodimer with SSTR3 and SSTR5. Heterodimerization with SSTR3 inactivates SSTR3 receptor function. Heterodimerization with SSTR5 is enhanced by agonist stimulation of SSTR2 and increases SSTR2 cell growth inhibition activity. Following agonist stimulation, homodimers dissociate into monomers which is required for receptor internalization. Interacts with beta-arrestin; this interaction is necessary for receptor internalization and is destabilized by heterodimerization with SSTR5 which results in increased recycling of SSTR2 to the cell surface. Interacts (via C-terminus) with SHANK1 (via PDZ domain)

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• Kopatz S.A. et al. Isolation of complete coding sequence for somatostatin receptor 2 (SSTR2). (FEB-)
• Suwa M. et al. Genome-wide discovery and analysis of human seven transmembrane helix receptor genes. (JUL-)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
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• Patel Y.C. et al. Multiple gene transcripts of the somatostatin receptor SSTR2: tissue selective distribution and cAMP regulation. — Biochem. Biophys. Res. Commun. (1993)