Somatostatin receptor type 1, 3, 4, and 5 (SSTR1, SSTR3, SSTR4, SSTR5)

Somatostatin receptors (SSTRs) are a family of five G protein-coupled receptors (SSTR1-5) that mediate the diverse inhibitory effects of the peptide hormone somatostatin across the central nervous system and peripheral tissues [1.1.1, 1.4.1]. This specific subset—SSTR1, SSTR3, SSTR4, and SSTR5—regulates critical physiological processes including the secretion of growth hormone, insulin, glucagon, and adrenocorticotropic hormone (ACTH), as well as modulating neuronal excitability and cell proliferation [1.1.3, 1.1.4]. SSTR1 and SSTR4 are structurally related and are prominently expressed in the brain, where they are investigated as targets for treating chronic pain and cognitive disorders like Alzheimer's disease [1.4.2]. SSTR3 is uniquely associated with the induction of PTP-dependent apoptosis and is frequently expressed in non-functioning pituitary adenomas [1.1.4, 1.2.4]. SSTR5 is a major regulator of insulin and ACTH release, making it a primary therapeutic target for Cushing's disease and acromegaly [1.3.2, 1.3.3]. These receptors are targeted by multireceptor-ligand somatostatin analogs such as pasireotide, which provides a broader therapeutic window for neuroendocrine tumors that are resistant to SSTR2-selective agents [1.3.1, 1.3.4].

Other names

Somatostatin receptor 1Somatostatin receptor 3Somatostatin receptor 4Somatostatin receptor 5SST1SST3SST4SST5SRIF-1SRIF-3SRIF-4SRIF-5SS1RSS3RSS4RSS5R

Agonism of G protein-coupled receptors leading to the inhibition of adenylyl cyclase, reduction of intracellular cAMP levels, and activation of phosphotyrosine phosphatases (PTP).