A Calcium channel is an ion channel which displays selective permeabiltiy to calcium ions. It is sometimes synonymous as voltage-dependent calcium channel, although there are also ligand-gated calcium channels.
The following tables explain gating, gene, location and function of different types of calcium channels, both voltage and ligand-gated.
|L-type||high voltage|| Cav1.1
|Skeletal muscle, bone (osteoblasts), ventricular myocytes**, dendrites and dendritic spines of cortical neurones||SMC and cardiac muscle contraction . Responsible for prolonged action potential in cardiac muscle.|
|P-type/Q-type||high voltage||Cav2.1||CACNA1A||Purkinje neurons in the cerebellum / Cerebellar granule cells||neurotransmitter release |
|N-type||high voltage||Cav2.2||CACNA1B||Throughout the brain||neurotransmitter release |
|R-type||intermediate voltage||Cav2.3||CACNA1E||Cerebellar granule cells, other neurons||?|
|T-type||low voltage|| Cav3.1
|neurons, cells that have pacemaker activity, bone (osteocytes)||Regular sinus rhythm|
|IP3 receptor||IP3||ER/SR||Releases calcium from ER/SR in response to IP3 by e.g. GPCRs |
|Ryanodine receptor||dihydropyridine receptors in T-tubules||ER/SR||Calcium-induced calcium release in myocytes |
|Cation channels of sperm|
|store-operated channels||indirectly by ER/SR depletion of calcium||plasma membrane|