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Gene Family: Calcium voltage-gated channel auxiliary alpha2delta subunits (CACNA2D)

Voltage-dependent calcium channel: Voltage-dependent calcium channels ( VDCCs ) are a group of voltage-gated ion channels found in the membrane of excitable cells ( e.g., muscle, glial cells, neurons, etc.) with a permeability to the calcium ion Ca 2+. These channels are slightly permeable to sodium ions, so they are also called Ca 2+ -Na + channels, but their permeability to calcium is about 1000-fold greater than to sodium under normal physiological conditions. At physiologic or resting membrane potential, VDCCs are normally closed. They are activated ( i.e., opened) at depolarized membrane potentials and this is the source of the "voltage-dependent" epithet. The concentration of calcium (Ca 2+ ions) is normally several thousand times higher outside of the cell than inside. Activation of particular VDCCs allows Ca 2+ to rush into the cell, which, depending on the cell type, results in activation of calcium-sensitive potassium channels, muscular contraction, excitation of neurons, up-regulation of gene expression, or release of hormones or neurotransmitters. VDCCs have been immunolocalized in the zona glomerulosa of normal and hyperplastic human adrenal, as well as in aldosterone -producing adenomas (APA), and in the latter T-type VDCCs correlated with plasma aldosterone levels of patients. Excessive activation of VDCCs is a major component of excitotoxicity, as severely elevated levels of intracellular calcium activates enzymes which, at high enough levels, can degrade essential cellular structures. [Source: Wikipedia]

Genes contained within the family: 4

Approved Symbol Approved Name Previous Symbols Synonyms Chromosome
CACNA2D1 calcium voltage-gated channel auxiliary subunit alpha2delta 1 CACNL2A, CACNA2, MHS3, LINC01112 lncRNA-N3 7q21.11
CACNA2D2 calcium voltage-gated channel auxiliary subunit alpha2delta 2 KIAA0558 3p21.31
CACNA2D3 calcium voltage-gated channel auxiliary subunit alpha2delta 3 HSA272268 3p21.1-p14.3
CACNA2D4 calcium voltage-gated channel auxiliary subunit alpha2delta 4 12p13.33

Comments

The α2δ gene forms two subunits: α2 and δ (which are both the product of the same gene). They are linked to each other via a disulfide bond and have a combined molecular weight of 170 kDa. The α2 is the extracellular glycosylated subunit that interacts the most with the α1 subunit. The δ subunit has a single transmembrane region with a short intracellular portion, which serves to anchor the protein in the plasma membrane. There are 4 α2δ genes.

Publications

16382099