Regulation of effectors by G-protein alpha- and beta gamma-subunits. Recent insights from studies of the phospholipase c-beta isoenzymes.
Both the alpha- and beta gamma-subunits of heterotrimeric guanine nucleotide-dependent regulatory proteins (G-proteins) couple members of the heptahelical class of cell-surface receptors to a diverse range of signal-generating effectors including retinal cyclic GMP phosphodiesterase, ion channels, adenylylcyclases, phosphoinositide 3-kinase, and members of the beta-class of inositol lipid-specific phospholipases C. Although the molecular details of the G-protein-regulated phospholipase C system were elucidated comparatively recently, these enzymes have become an important model for investigations of the process of G-protein effector coupling. A combination of molecular biological, biochemical, and structural studies using the phospholipase C-beta enzymes has provided some important insights into the interplay between G-proteins and their effectors and promises to reveal the mechanisms by which G-protein alpha- and beta gamma-subunits selectively associate with and activate effectors.
Morris
A J
AJ
Department of Pharmacological Sciences, Stony Brook Health Science Center, NY 11794, USA.
Scarlata
S
S
D000818:Animals; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism*
D007527:Isoenzymes; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins