Voltage-gated calcium channel α2-δ subunit (α2-δ subunit)

The Voltage-gated calcium channel α2-δ subunit is an auxiliary protein essential for the proper function of high-voltage-activated calcium channels in neurons, muscle, and other excitable cells. It regulates the trafficking, localization, and gating characteristics of the channel complex, augmenting membrane expression and altering activation/inactivation kinetics. The α2-δ subunit serves as the molecular target for gabapentinoid drugs like gabapentin and pregabalin; binding of these drugs selectively inhibits subunit trafficking and reduces calcium channel density, suppressing neurotransmitter release and attenuating neuropathic pain. The subunit family consists of four isoforms (α2-δ-1 to α2-δ-4), each encoded by distinct CACNA2D genes and variably expressed across tissues. Dysfunction of α2-δ subunits is implicated in various CNS and pain disorders, making it a key drug target in neurology and pain management.

Other names

Calcium channel α2δ subunitAlpha-2-delta subunitCACNA2D (gene family, e.g. CACNA2D1, CACNA2D2 for isoforms)α2δ-1α2δ-2α2δ-3α2δ-4 (specific subunit isoforms)

Gabapentinoids bind the α2-δ subunit, inhibiting its trafficking and ability to increase plasma membrane localization of calcium channels. This reduces presynaptic calcium influx and neurotransmitter release, providing analgesic and anti-epileptic effects