Target type: biologicalprocess
A G protein-coupled receptor signaling pathway initiated by somatostatin binding to a somatostatin receptor (SSTR), and ending with the regulation of a downstream cellular process, e.g. transcription. [GOC:bf, GOC:nhn, GOC:signaling, PMID:18006219, Wikipedia:Somatostatin]
Somatostatin, a peptide hormone, plays a critical role in regulating a wide range of physiological processes by inhibiting the release of various hormones. The somatostatin signaling pathway involves a series of events that begin with the binding of somatostatin to its specific G protein-coupled receptors (SSTRs). There are five known SSTR subtypes (SSTR1-5), each with distinct tissue distribution and signaling characteristics. Upon somatostatin binding, the receptor undergoes conformational changes that activate intracellular signaling cascades. The primary signaling pathway involves the inhibition of adenylate cyclase activity, leading to a decrease in cyclic adenosine monophosphate (cAMP) levels. This reduction in cAMP inhibits the activation of protein kinase A (PKA), a key enzyme involved in various cellular processes. In addition to cAMP signaling, somatostatin activation of SSTRs also triggers the activation of other signaling pathways, including the phosphoinositide 3-kinase (PI3K) pathway, the mitogen-activated protein kinase (MAPK) pathway, and the RhoA pathway. These pathways regulate various cellular functions, including cell growth, proliferation, and survival. Somatostatin signaling plays a crucial role in regulating hormone release from the pituitary gland, pancreas, gastrointestinal tract, and other endocrine tissues. It inhibits the release of growth hormone, insulin, glucagon, and other hormones, contributing to the maintenance of homeostasis. Furthermore, somatostatin has been implicated in various physiological processes, including appetite regulation, neurotransmission, and immune modulation. Dysregulation of somatostatin signaling has been associated with various pathological conditions, including acromegaly, diabetes mellitus, and cancer. The understanding of the complex mechanisms underlying somatostatin signaling pathway is essential for developing therapeutic strategies targeting SSTRs for the treatment of various diseases.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Somatostatin receptor type 5 | A somatostatin receptor type 5 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P35346] | Homo sapiens (human) |
| Somatostatin receptor type 3 | A somatostatin receptor type 3 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P32745] | Homo sapiens (human) |
| Somatostatin receptor type 4 | A somatostatin receptor type 4 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P31391] | Homo sapiens (human) |
| Somatostatin receptor type 2 | A somatostatin receptor type 2 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P30874] | Homo sapiens (human) |
| Somatostatin receptor type 1 | A somatostatin receptor type 1 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P30872] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| astemizole | astemizole : A piperidine compound having a 2-(4-methoxyphenyl)ethyl group at the 1-position and an N-[(4-fluorobenzyl)benzimidazol-2-yl]amino group at the 4-position. Astemizole: Antihistamine drug now withdrawn from the market in many countries because of rare but potentially fatal side effects. | benzimidazoles; piperidines | anti-allergic agent; anticoronaviral agent; H1-receptor antagonist |
| camptothecin | NSC 100880: carboxylate (opened lactone) form of camptothecin; RN refers to (S)-isomer; structure given in first source | delta-lactone; pyranoindolizinoquinoline; quinoline alkaloid; tertiary alcohol | antineoplastic agent; EC 5.99.1.2 (DNA topoisomerase) inhibitor; genotoxin; plant metabolite |
| edotreotide | Edotreotide: DOTA - 1,4,7,10-tetraazacyclododecanetetracetic acid; structure given in first source; may be labelled with various radioisotopes | ||
| octreotide | |||
| l803087 | L-803087 : A fluoroindole that is 1H-indole substituted by phenyl, 4-{[(2S)-5-carbamimidamido-1-methoxy-1-oxopentan-2-yl]amino}-4-oxobutyl, fluoro and fluoro groups at positions 2, 3, 5 and 7, respectively. It is a selective nonpeptidic agonist of the somatostatin subtype-4 (SST4) receptor with Ki of 0.7 nM. L803087: structure in first source | benzenes; fluoroindole; guanidines; L-arginine derivative; methyl ester; phenylindole; secondary carboxamide | somatostatin receptor agonist |
| obelin | obelin: calcium-sensitive photoprotein obtained from the hydroid Obelia geniculata | ||
| seglitide | seglitide: more potent than somatostatin for inhibition of insulin, glucagon & growth hormone release; used experimentally in treatment of Alzheimer's disease; somatostatin receptor antagonist | ||
| lanreotide | |||
| nnc 26-9100 | NNC 26-9100: structure in first source | aminopyridine | |
| l 363301 | |||
| pasireotide | pasireotide : A six-membered homodetic cyclic peptide composed from L-phenylglycyl, D-tryptophyl, L-lysyl, O-benzyl-L-tyrosyl, L-phenylalanyl and modified L-hydroxyproline residues joined in sequence. A somatostatin analogue with pharmacologic properties mimicking those of the natural hormone somatostatin; used (as its diaspartate salt) for treatment of Cushing's disease. | homodetic cyclic peptide; peptide hormone | antineoplastic agent |
| naluzotan | naluzotan: an antidepressant and anti-anxiety agent; structure in first source | ||
| (1's, 2s)-4-amino-n-(1'-carbamoyl-2'-phenylethyl)-2-(4''-methyl-1''-naphthalenesulfonylamino)butanamide | (1'S, 2S)-4-amino-N-(1'-carbamoyl-2'-phenylethyl)-2-(4''-methyl-1''-naphthalenesulfonylamino)butanamide: a somatostatin receptor 4 agonist; structure in first source | ||
| l 054522 | L 054522: somatostatin receptor subtype 2 agonist; structure in first source | ||
| somatostatin | heterodetic cyclic peptide; peptide hormone | ||
| prosomatostatin | heterodetic cyclic peptide; peptide hormone | fungal metabolite; mouse metabolite; rat metabolite |