RECEPTOR-REGULATED ION CHANNELS

Recent advances in the study of receptor-regulated ion channels includ e the cloning of the genes encoding three types of potassium channel t hat are favorite targets of receptors for transmitters and hormones. S tudies of these channels have also provided a strong indication that G -protein py subunits may gate ion channels via direct protein-protein interactions. Similarities between channel regulation by natriuretic p eptides and channel regulation by secreted peptide products of the Alz heimer's P-amyloid precursor protein offer hints for the existence of a receptor for the latter. There are also other novel examples of chan nel regulation in excitable and nonexcitable cells, including liver ce lls and blood cells.