The G-protein-gated atrial K+ channel IKAch is a heteromultimer of two inwardly rectifying K+-channel proteins

Heart rate is slowed in part by acetylcholine-dependent activation of a cardiac potassium (K+) channel, IKACh. Activated muscarinic receptors stimulate lKAch via the G-protein βγ-subunits. It has been assumed that the inwardly rectifying K+-channel gene, GIRK1, alone encodes IKAch-It is now shown that IKAch is a heteromultimer of two distinct inwardly rectifying K+-channel subunits, GIRK1 and a newly cloned member of the family, CIR.

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