The importance of G-protein βλ subunits

As the properties of more and more isoforms of the molecules involved in G-protein-mediated signal transduction pathways are unravelled, surprising diversity and versatility are being revealed. The path from receptor to effector is not dictated exclusivelt by the α subunits of heterotrimetric G proteins. The nature of the βλ subunit complex probably controls interactions of G_α with receptors. In addition, dissociation of G_α-GTP from G_βλprovides two signalling complexes, and these proteins regulate effectors independently or synergistically. Synergistic or conditional regulation of effectors by G_α and G_βλcan provide a molecular signal that records the association of independent events.