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.
Additional recommended knowledge
Comparison tables
The following tables explain gating, gene, location and function of different types of calcium channels, both voltage and ligand-gated.
Voltage-gated
Type Gated by Protein Gene Location Function
L-type high voltage Cav 1.1 Cav 1.2 Cav 1.3 Cav 1.4 CACNA1S CACNA1C CACNA1D CACNA1F Skeletal muscle, bone (osteoblasts), ventricular myocytes**, dendrites and dendritic spines of cortical neurones SMC and cardiac muscle contraction [1] . Responsible for prolonged action potential in cardiac muscle .
P-type /Q-type high voltage Cav 2.1 CACNA1A Purkinje neurons in the cerebellum / Cerebellar granule cells neurotransmitter release [1]
N-type high voltage Cav 2.2 CACNA1B Throughout the brain neurotransmitter release [1]
R-type intermediate voltage Cav 2.3 CACNA1E Cerebellar granule cells, other neurons ?[1]
T-type low voltage Cav 3.1 Cav 3.2 Cav 3.3 CACNA1G CACNA1H CACNA1I neurons, cells that have pacemaker activity, bone (osteocytes) Regular sinus rhythm[1]
Ligand-gated
the receptor-operated calcium channels (in vasoconstriction)
Pharmacology
Calcium channel blockers are used to treat hypertension .
References
^ a b c d e f g h Rang, H. P. (2003). Pharmacology . Edinburgh: Churchill Livingstone. ISBN 0-443-07145-4 . Page 53
^ Walter F., PhD. Boron. Medical Physiology: A Cellular And Molecular Approaoch . Elsevier/Saunders. ISBN 1-4160-2328-3 . Page 479
Membrane transport protein : ion channels Ca2+ : Calcium channel Voltage-dependent calcium channel (L-type /Cav α (1.1, 1.2, 1.3, 1.4), N-type , P-type /Cav α (2.1), Q-type , R-type , T-type , β-subunits (β1, β2, β4), γ-subunits (γ2) • Inositol triphosphate receptor • Ryanodine receptor • Cation channels of sperm • Two-pore channel Na+ : Sodium channel Nav α (1.1, 1.2, 1.4, 1.5, 1.7, 1.9) • Nav β (1, 3, 4) • Epithelial sodium channel K+ : Potassium channel Voltage-gated (Kv α (1.1, 1.2, 1.3, 1.4, 1.5, 2.1, 4.2, 4.3, 7.1, 7.2, 7.3, 7.4, 10.1, 11.1/hERG) • Kv β (1, 2), Shaker gene, KCNE1) • Calcium-activated (BK channel , SK channel, SK3 ) • Inward-rectifier Kir (1.1, 2.1, 2.2, 2.3, 3.1, 3.2, 3.4, 4.1, 4.2, 6.1, 6.2)) • Tandem pore domain K2P (1, 2, 3, 4, 6, 9)Cl- : Chloride channel Cystic fibrosis transmembrane conductance regulator Porin Aquaporin (1 , 2 , 3 , 4 ) • Voltage-dependent anion channel (1) Cations: TRP TRPA (1 ) • TRPC (1, 2, 3, 4, 4AP, 5, 6, 7) • TRPM (1, 2, 3, 4, 5, 6, 7, 8) • TRPML (Mucolipin-1) • TRPP (1, 2 )• TRPV (1 , 2, 3, 4, 5, 6)Other/general Voltage-gated ion channel • Ligand-gated ion channel • Cyclic nucleotide-gated ion channel (α1, α3, β3, H1, H2, H4) • Stretch-activated ion channel