Gs alpha subunit

The Gs alpha subunit is a G protein subunit that activates the cAMP-dependent pathway by stimulating the activity of adenylate cyclase. This protein is encoded by the GNAS complex locus in humans.

Function

The Gs alpha subunit is a part of the heterotrimeric G protein complex, which is involved in transmitting signals from a variety of stimuli outside a cell to its interior. The Gs alpha subunit specifically activates adenylate cyclase, which in turn increases the levels of cyclic AMP (cAMP) in the cell. This increase in cAMP activates protein kinase A (PKA), leading to the phosphorylation of various target proteins and resulting in a wide range of cellular responses.

Clinical significance

Mutations in the Gs alpha subunit can lead to several disorders. For example, mutations that cause constitutive activation of the Gs alpha subunit are associated with McCune-Albright syndrome, a disorder characterized by polyostotic fibrous dysplasia, café-au-lait spots, and endocrine abnormalities.

Additionally, mutations in the Gs alpha subunit can result in pseudohypoparathyroidism, a condition where the body is resistant to the parathyroid hormone, leading to low calcium levels and high phosphate levels in the blood.

See also

• G protein-coupled receptor
• Signal transduction
• Heterotrimeric G protein

External links

• Template:GeneReviews
• Online Mendelian Inheritance in Man (OMIM) 139320