Guanine nucleotide-binding proteins (G proteins) transduce extracellular signals received by transmembrane receptors to effector proteins.
The activity of hormone-sensitive adenylate cyclase is regulated by at least 2 G proteins, 1 stimulatory (Gs) and 1 inhibitory (Gi) (MIM.139310). A third G protein, Go (MIM.139311), is abundant in brain.
Each G protein is a heterotrimer composed of an alpha, beta, and gamma subunit. The GNAS1 gene encodes the alpha subunit of the G stimulatory protein Gs.
Neuroendocrine secretory protein-55 (NESP-55), the latest addition to the chromogranin family, is a product of a genomically imprinted gene transcribed exclusively from the maternal allele.
Expression in tumors
pheochromocytoma
pancreatic endocrine tumors
neuroblastomas (50%) (#12771991#)
heterozygous deactivating GNAS1 mutations in Albright hereditary osteodystrophy (AHO)
mutations in fibrous dysplasia
liposclerosing myxofibrous tumor (#14652823#)
mutations of GNAS1
|GNAS1|Albright hereditary osteodystrophy| |GNAS1|pseudohypoparathyroidism type Ia (PHP Ia)| |GNAS1|pseudopseudohypoparathyroidism (PPHP)| |GNAS1|pituitary tumors| |GNAS1|fibrous dysplasia| |GNAS1|liposclerosing myxofibrous tumor|
Références
Srivastava A, Padilla O, Fischer-Colbrie R, Tischler AS, Dayal Y. Neuroendocrine secretory protein-55 (NESP-55) expression discriminates pancreatic endocrine tumors and pheochromocytomas from gastrointestinal and pulmonary carcinoids. Am J Surg Pathol. 2004 Oct;28(10):1371-8. PMID: #15371954#