G Protein Regulation of Inwardly Rectifying K(+) Channels.

Inwardly rectifying K(+) (Kir) channels respond to receptor-stimulated signaling cascades that involve G proteins and other cytosolic messengers. Channel activity is controlled both by direct coupling of G protein subunits and by phosphorylation via protein serine/threonine and tyrosine kinases. The coincidence of both forms of Kir channel signaling may give rise to complex cellular responses.