L-type calcium channel CaV1.2 (vascular smooth muscle isoform) (CaV1.2)

The L-type calcium channel CaV1.2 (vascular smooth muscle isoform) is a voltage-gated ion channel that serves as the primary pathway for Ca2+ influx in vascular smooth muscle cells (VSMCs), enabling membrane depolarization-induced contraction and maintenance of myogenic tone. Composed of a pore-forming α1C (CaV1.2) subunit along with auxiliary β (predominantly β3), α2δ, and γ subunits, it forms heteromeric complexes that regulate channel trafficking, gating, and Ca2+ selectivity. Activation occurs at depolarized potentials typical of VSMCs, coupling pressure or agonist-induced depolarization to Ca2+ entry that triggers contraction via calmodulin and RhoA pathways. It is essential for autoregulation of blood flow, phenylephrine- or angiotensin II-induced vasoconstriction, and blood pressure control, as evidenced by smooth muscle-specific knockout studies showing abolished L-type currents, blunted vasoconstriction, and reduced myogenic responses. In disease, dysregulation contributes to hypertension and vascular hypercontractility; its expression correlates with VSMC differentiation markers like SM α-actin and myosin heavy chain. Therapeutically, it is targeted by calcium channel blockers (e.g., dihydropyridines) that inhibit Ca2+ entry to promote vasodilation, though challenges include isoform-specific regulation and off-target effects on cardiac channels.

Other names

L-type Ca2+ channelLTCCvoltage-dependent L-type calcium channelCaV1.2 channel

Calcium channel blockade inhibiting Ca2+ influx to reduce vascular smooth muscle contraction and blood pressure, Voltage-dependent inhibition of Ca2+ current