D. Kim, D.L. Lewis, L. Graziadei, E.J. Neer, D. Bar-Sagi, D.E. Clapham, "G-protein áç-subunits activate the cardiac muscarinic K+-channel via phospholipase A2," Nature, 337, 557-60, 9 February 1989. David Clapham (Mayo Foundation, Rochester, Minn.): "More than 70 (for example, à,á, muscarinic, and rhodopsin) receptor types are linked to their effectors via G proteins. These G proteins are composed of two functional subunits, known as Gà and Gáà. Although the evidence that the Gà subunit activates effectors is well known, we proposed in an earlier paper that in some cases the Gáà subunit may also activate an effector, the cardiac muscarinic-gated potassium channel (Logothetis, et al., Nature, 325: 321-6, 1987). This idea was controversial, since most evidence supports Gáà's main role to be as an inhibitor of Gà. This paper proposed that Gáà activates the cardiac potassium channel via stimulation of phospholipase A2 and subsequent...