Developmental changes and regulation of L-type calcium channels of myocardial cells and vascular smooth muscle cells

Phosphorylation of ion channels is a means of regulating or modulating the activity of the channels. There is evidence for such regulation or modulation of function of Ca2+, K+, and Na+ channels by phosphorylation, and biochemical evidence shows that one or a few sites on the channel proteins can be phosphorylated by various protein kinases. Most of the physiological evidence for modulation of ion channel function by cyclic-nucleotide-dependent phosphorylation is for slow (L-type) Ca2+ channels of cardiac muscle, vascular smooth muscle (VSM), skeletal muscle, and nerve, and for K+ channels (delayed rectifier type) of cardiac muscle and nerve. This article will focus primarily on the slow Ca2+ channel of cardiac muscle and VSM.