Guanine nucleotide-binding protein G(s) subunit alpha isoforms short
Histamine H2 receptor
Histamine receptor H2
The H2 subclass of histamine receptors mediates gastric acid secretion. It also appears to regulate gastrointestinal motility and intestinal secretion. HRH2 has a possible role in regulating cell growth and differentiation. The activity of this receptor is mediated by G proteins which activate adenylyl cyclase and, through a separate G protein dependent mechanism, the phosphoinositide/protein kinase (PKC) signaling pathway.
Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The Gs protein is involved in hormonal regulation of adenylate cyclase: it activates the cyclase in response to beta-adrenergic stimuli.
Alternative splicing of downstream exons of the GNAS gene is observed, which results in different forms of the stimulatory G protein alpha subunit, a key element of the classical signal transduction pathway linking receptor-ligand interactions with the activation of adenylyl cyclase and a variety of cellular reponses. Multiple transcript variants have been found for this gene, but the full-length nature and/or biological validity of some variants have not been determined.