A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated 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.
|Type||Voltage||α1 subunit (gene name)||Associated subunits||Most often found in|
|L-type calcium channel ("Long-Lasting" AKA "DHP Receptor")||HVA (high voltage activated)||Cav1.1 (CACNA1S)
Cav1.2 (CACNA1C) Cav1.3 (CACNA1D)
|α2δ, β, γ||Skeletal muscle, smooth muscle, bone (osteoblasts), ventricular myocytes** (responsible for prolonged action potential in cardiac cell; also termed DHP receptors), dendrites and dendritic spines of cortical neurons|
|N-type calcium channel ("Neural"/"Non-L")||HVA (high-voltage-activated)||Cav2.2 (CACNA1B)||α2δ/β1, β3, β4, possibly γ||Throughout the brain and peripheral nervous system.|
|P-type calcium channel ("Purkinje") /Q-type calcium channel||HVA (high voltage activated)||Cav2.1 (CACNA1A)||α2δ, β, possibly γ||Purkinje neurons in the cerebellum / Cerebellar granule cells|
|R-type calcium channel ("Residual")||intermediate-voltage-activated||Cav2.3 (CACNA1E)||α2δ, β, possibly γ||Cerebellar granule cells, other neurons|
|T-type calcium channel ("Transient")||low-voltage-activated||Cav3.1 (CACNA1G)
|neurons, cells that have pacemaker activity, bone (osteocytes), thalamus (thalamus)|
- the receptor-operated calcium channels (in vasoconstriction)
|IP3 receptor||IP3||ITPR1, ITPR2, ITPR3||ER/SR||Releases calcium from ER/SR in response to IP3 by e.g. GPCRs|
|Ryanodine receptor||dihydropyridine receptors in T-tubules and increased intracellular calcium (Calcium Induced Calcium Release - CICR)||RYR1, RYR2, RYR3||ER/SR||Calcium-induced calcium release in myocytes|
|Two-pore channel||Nicotinic acid adenine dinucleotide phosphate (NAADP)||TPCN1, TPCN2||endosomal/lysosomal membranes||NAADP-activated calcium transport across endosomal/lysosomal membranes|
|Cation channels of sperm||Calcium (CICR)||PKD2 family||sperm (specifically flagella)||Non-selective calcium-activated cation channel directing sperm in female reproductive tract|
|store-operated channels||indirectly by ER/SR depletion of calcium||ORAI1, ORAI2, ORAI3||plasma membrane||Provides calcium signaling to the cytoplasm|
L-type calcium channel blockers are used to treat hypertension. In most areas of the body, depolarization is mediated by sodium influx into a cell; changing the calcium permeability has little effect on action potentials. However, in many smooth muscle tissues, depolarization is mediated primarily by calcium influx into the cell. L-type calcium channel blockers selectively inhibit these action potentials in smooth muscle which leads to dilation of blood vessels; this in turn corrects hypertension.
T-type calcium channel blockers are used to treat epilepsy. Increased calcium conductance in the neurons leads to increased depolarization and excitability. This leads to a greater predisposition to epileptic episodes. Calcium channel blockers reduce the neuronal calcium conductance and reduce the likelihood of experiencing epileptic attacks.
- Calcium in biology – Use of calcium by organisms.
- ^ "calcium channel" at Dorland's Medical Dictionary
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- ^ "TPCN1 - Two pore calcium channel protein 1 - Homo sapiens (Human) - TPCN1 gene & protein". www.uniprot.org. Retrieved 2017-12-11.
- ^ Gao Z, Ruden DM, Lu X (December 2003). "PKD2 cation channel is required for directional sperm movement and male fertility". Current Biology. 13 (24): 2175–2178. doi:10.1016/j.cub.2003.11.053. PMID 14680633.
- ^ Putney JW, Steinckwich-Besançon N, Numaga-Tomita T, Davis FM, Desai PN, D'Agostin DM, et al. (June 2017). "The functions of store-operated calcium channels". Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1864 (6): 900–906. doi:10.1016/j.bbamcr.2016.11.028. PMC 5420336. PMID 27913208.
- ^ Katz AM (September 1986). "Pharmacology and mechanisms of action of calcium-channel blockers". Journal of Clinical Hypertension. 2 (3 Suppl): 28S–37S. PMID 3540226.
- ^ Zamponi GW, Lory P, Perez-Reyes E (July 2010). "Role of voltage-gated calcium channels in epilepsy". Pflügers Archiv. 460 (2): 395–403. doi:10.1007/s00424-009-0772-x. PMC 3312315. PMID 20091047.
- "The Weiss Lab". The Weiss Lab is investigating the molecular and cellular mechanisms underlying human diseases caused by dysfunction of ion channels.
- "Voltage-Gated Ion Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
- "TRIP Database". a manually curated database of protein-protein interactions for mammalian TRP channels. Archived from the original on 2016-08-10. Retrieved 2021-06-18.
- Calcium+Channels at the U.S. National Library of Medicine Medical Subject Headings (MeSH)