High-voltage-activated voltage-gated calcium channel (HVA VGCC) (HVA VGCC)

High-voltage-activated voltage-gated calcium channels (HVA VGCCs) are a class of transmembrane proteins that open in response to significant membrane depolarization to allow the influx of calcium ions into excitable cells [1, 12]. They are heteromultimeric complexes composed of a pore-forming alpha-1 subunit (Cav1 or Cav2 families) and auxiliary subunits such as alpha-2-delta and beta, which modulate channel gating and trafficking [1, 6]. These channels are subdivided into L-type (Cav1.1-1.4), P/Q-type (Cav2.1), N-type (Cav2.2), and R-type (Cav2.3) based on their pharmacological and biophysical properties [3, 12]. HVA VGCCs play a fundamental role in converting electrical signals into intracellular calcium transients, thereby triggering critical physiological processes including muscle contraction, neurotransmitter release, and gene expression [6, 10]. They are major therapeutic targets; L-type channels are targeted by dihydropyridines and other blockers for treating hypertension and angina, while N-type channels and the alpha-2-delta subunit are targeted for the management of chronic and neuropathic pain [4, 8]. Dysregulation of these channels is implicated in a wide range of pathologies, including cardiovascular disorders, epilepsy, and neurodegenerative diseases [5, 9]. Pharmacological intervention typically involves either direct pore blockade or modulation of the channel's voltage-sensing apparatus [8, 11].

Other names

HVA calcium channelHigh-threshold calcium channelHigh-voltage-activated calcium channelHVA VGCC

Drugs targeting HVA VGCCs act through several mechanisms: L-type calcium channel blockers (e.g., dihydropyridines) bind to the alpha-1 subunit to inhibit ion conductance or stabilize the inactivated state [3, 8]. N-type blockers like ziconotide physically block the channel pore [8, 11]. Gabapentinoids bind to the alpha-2-delta auxiliary subunit, which reduces the trafficking of the channel complex to the plasma membrane and inhibits neurotransmitter release [11, 12].