CACN

Voltage-dependent calcium channels ( VDCC ) 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. 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. (hgnc.genefamily:253)

Cross-references

Synonyms

None available.

Incoming Relations

Identifier Name Relation
FPLX:CACNA1 CACNA1 isa
FPLX:CACNA2D CACNA2D isa
FPLX:CACNG CACNG isa
FPLX:CACNB CACNB isa

Outgoing Relations

Relation Identifier Name
isa FPLX:Voltage_gated_ion_channels Voltage_gated_ion_channels
isa FPLX:Calcium_channels Calcium_channels