The alpha-2/delta subunit of voltage-dependent calcium channels regulates calcium current density and activation/inactivation kinetics of the calcium channel. Dimer formed of alpha-2-2 and delta-2 chains; disulfide-linked. Voltage-dependent calcium channels are multisubunit complexes, consisting of alpha-1 (CACNA1), alpha-2 (CACNA2D), beta (CACNB) and delta (CACNA2D) subunits in a 1:1:1:1 ratio (Probable). Interacts with CACNA1C and CACNB3. Predominantly expressed in certain types of endocrine cells. Present in the Paneth cells of the small intestine. Also present in the erythroblasts in the fetal liver, in the cells of the zona reticularis of the adrenal gland and in the basophils of the pituitary. Present at low level in some brain regions such as the cerebellum (at protein level). The MIDAS-like motif in the VWFA domain binds divalent metal cations and is required to promote trafficking of the alpha-1 (CACNA1) subunit to the plasma membrane by an integrin-like switch. May be proteolytically processed into subunits alpha-2-4 and delta-4 that are disulfide-linked. It is however unclear whether such cleavage really takes place in vivo and has a functional role (By similarity). The disease is caused by variants affecting the gene represented in this entry. In contrast to CACNA2D1 and CACNA2D2, it does not bind gabapentin, an antiepileptic drug. May be due to an intron retention. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the calcium channel subunit alpha-2/delta family. Wrong choice of frame. Truncated N-terminus.