Heterotrimeric G-protein alpha subunit (Gα) (Gα)

Heterotrimeric G-protein alpha subunits (Gα) are essential molecular switches that mediate signal transduction from G protein-coupled receptors (GPCRs) to intracellular effector proteins (Source: UniProt, P63092). Upon ligand binding to a GPCR, the Gα subunit undergoes a conformational change, exchanging bound GDP for GTP and dissociating from the Gβγ complex to regulate downstream targets like adenylyl cyclase or phospholipase C (Source: StatPearls, G Protein-Coupled Receptors). These subunits are classified into four main families—Gs, Gi/o, Gq/11, and G12/13—each initiating distinct signaling cascades (Source: PubMed, PMC3743447). Dysregulation or somatic mutations in Gα subunits are implicated in numerous diseases, including uveal melanoma (GNAQ/GNA11 mutations) and McCune-Albright syndrome (GNAS mutations) (Source: NIH, Genetics Home Reference). While traditionally targeted indirectly via GPCRs, direct pharmacological modulation of Gα subunits using small molecules like YM-254890 is an emerging therapeutic strategy for G-protein-driven pathologies (Source: PubMed, PMID: 30104373).

Other names

Guanine nucleotide-binding protein alpha subunitG-alpha subunitG protein alpha subunit

Direct inhibition of GDP/GTP exchange on the alpha subunit, preventing dissociation from the G-beta-gamma complex and subsequent downstream signaling (Source: PubMed, PMID: 29453242).