L-type voltage-gated calcium channel subunit alpha-1C (Cav1.2)

The L-type voltage-gated calcium channel subunit alpha-1C (Cav1.2), encoded by the CACNA1C gene, is the principal pore-forming and voltage-sensing subunit of the cardiac L-type calcium channel complex[3][5][9]. This ion channel mediates the influx of calcium ions into cardiomyocytes during the plateau phase of the cardiac action potential, a process that triggers excitation-contraction coupling and subsequent cardiac muscle contraction[3][5][7][9]. The channel is a heterotetramer composed of the alpha-1C subunit and accessory beta, alpha2delta, and sometimes gamma subunits, which together modulate channel gating and trafficking[1][3][5]. Cav1.2 is sensitive to the dihydropyridine class of drugs and represents the primary molecular target for clinically used non-dihydropyridine calcium channel blockers (such as verapamil and diltiazem) and dihydropyridine blockers (such as amlodipine and nifedipine), which are prescribed for hypertension, angina, and various cardiac arrhythmias[2][4][5][6][8]. Dysfunction or mutations in this channel are implicated in cardiovascular diseases including arrhythmias and congenital long QT syndrome, as well as syndromic diseases such as Timothy syndrome[6][9]. Modulation of Cav1.2 activity, while therapeutically valuable, is associated with notable risks, especially when cardiac conduction or contractility is severely depressed by excessive channel blockade[4][6]. Additional notes: - "Cardiac calcium channel" is not sufficiently specific, as both L-type (primarily Cav1.2) and T-type (such as Cav3.1) channels exist in the heart. However, in the context of drug targeting and most cardiovascular pharmacology, the term almost universally refers to the **L-type, Cav1.2** channel[3][5][9]. - The gene name **CACNA1C** and protein abbreviation **Cav1.2** are standard for this target[3][5]. - The main molecular class is "ion channel", more specifically, a subtype of voltage-gated calcium channel[9]. - Common clinical drugs target this channel in the context of cardiovascular disease[4][6]. If the intention was to refer to "any cardiac calcium channel" in general (including T-type or others), this would require a broader designation and multiple canonical names. For therapeutic relevance, specificity for "L-type voltage-gated calcium channel subunit alpha-1C (Cav1.2)" is most accurate.

Other names

Cardiac L-type calcium channelCav1.2 channelVoltage-dependent L-type calcium channelDihydropyridine receptor (in context of muscle)CACNA1C (gene and protein)Cardiac calcium channel

Blockade of voltage-dependent L-type calcium current, Inhibition of calcium influx into cardiac myocytes, Decreased cardiac contractility, Reduction of heart rate, Vasodilation (for some subclasses), Modification of action potential duration