Title: The beta gamma subunits of GTP-binding proteins activate the muscarinic K+ channel in heart.

Authors: D E Logothetis, Y Kurachi, J Galper, E J Neer, D E Clapham

Journal, date & volume: Nature, 1987 Jan 22-28 , 325, 321-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/2433589

Abstract
Subunits of guanine nucleotide regulatory proteins purified from bovine cerebral cortex were used to perfuse the intracellular surface of excised patches of chick embryonic atrial cells. Single-channel current measurements unexpectedly indicate that the beta gamma, and not the alpha subunits, are responsible for activating the muscarinic-gated potassium channel.