L-type voltage-dependent calcium channel (L-type Ca²⁺ channel)

L-type calcium channels are voltage-dependent calcium channels that allow calcium influx into cells following membrane depolarization. They are critical for muscle contraction, particularly in cardiac tissue where they contribute to the plateau phase of the action potential. These channels form complex structures with multiple subunits, with the α₁ subunit forming the ion-conducting pore and containing the voltage sensor and drug binding sites. L-type channels are distinguished from other voltage-gated calcium channels (N-type, P/Q-type, R-type, and T-type) by their sensitivity to dihydropyridines and their biophysical properties. They play essential roles in excitation-contraction coupling, neuronal function, and various cellular signaling pathways, making them important therapeutic targets for cardiovascular and neurological conditions.

Other names

L-type calcium channelDihydropyridine receptor (DHPR)Classical dihydropyridine receptorCaV1 channel

Drugs targeting L-type calcium channels typically act as channel blockers (antagonists) that prevent calcium influx or channel activators (agonists) that enhance calcium influx. These drugs bind to specific sites on the α₁ subunit. Phosphorylation by protein kinase A (PKA) can also regulate channel activity.