Voltage-gated calcium channels and their auxiliary subunits: physiology and pathophysiology and pharmacology

Voltage-gated calcium channels are essential players in many physiological processes in excitable cells. There are three main subdivisions of calcium channel, defined by the pore-forming (1) subunit, the Ca(V)1, Ca(V)2 and Ca(V)3 channels. For all the subtypes of voltage-gated calcium channel, their gating properties are key for the precise control of neurotransmitter release, muscle contraction and cell excitability, among many other processes. For the Ca(V)1 and Ca(V)2 channels, their ability to reach their required destinations in the cell membrane, their activation and the fine tuning of their biophysical properties are all dramatically influenced by the auxiliary subunits that associate with them. Furthermore, there are many diseases, both genetic and acquired, involving voltage-gated calcium channels. This review will provide a general introduction and then concentrate particularly on the role of auxiliary (2) subunits in both physiological and pathological processes involving calcium channels, and as a therapeutic target.