Calcium channel
Encyclopedia
A Calcium channel is an ion channel
which displays selective permeability to calcium
ions. It is sometimes synonymous as voltage-dependent calcium channel
, although there are also ligand-gated calcium channels.
Ligand-gated
Ion channel
Ion channels are pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of cells by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells...
which displays selective permeability to calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
ions. It is sometimes synonymous as voltage-dependent calcium channel
Voltage-dependent calcium channel
Voltage-dependent calcium channels are a group of voltage-gated ion channels found in excitable cells with a permeability to the ion Ca2+...
, although there are also ligand-gated calcium channels.
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 L-type calcium channel The L-type calcium channel is a type of voltage-dependent calcium channel. "L" stands for long-lasting referring to the length of activation. Like the others of this class, the α1 subunit is the one that determines most of the channel's properties.... |
high voltage | Cav1.1 Cav1.1 Cav1.1 also known as the calcium channel, voltage-dependent, L type, alpha 1S subunit, , is a protein which in humans is encoded by the CACNA1S gene... Cav1.2 Cav1.3 Cav1.3 Cav1.3 also known as the calcium channel, voltage-dependent, L type, alpha 1D subunit , is a human gene.-External links:... Cav1.4 Cav1.4 Cav1.4 also known as the calcium channel, voltage-dependent, L type, alpha 1F subunit , is a human gene.-External Links:*... |
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Skeletal muscle, bone (osteoblasts), ventricular myocytes**, dendrites and dendritic spines of cortical neurons | cardiac muscle Cardiac muscle Cardiac muscle is a type of involuntary striated muscle found in the walls and histologic foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle... contraction. Responsible for prolonged action potential in cardiac muscle Cardiac muscle Cardiac muscle is a type of involuntary striated muscle found in the walls and histologic foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle... . >- | P-type P-type calcium channel The p-type calcium channel is a type of voltage-dependent calcium channel. Like the others of this class, the α1 subunit is the one that determines most of the channel's properties.... /Q-type Q-type calcium channel The Q-type calcium channel is a type of voltage-dependent calcium channel. Like the others of this class, the α1 subunit is the one that determines most of the channel's properties.... |
high voltage | Cav2.1 Cav2.1 The Cav2.1 P/Q voltage-dependent calcium channel is encoded by the gene.Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release,... |
Purkinje neurons in the cerebellum / Cerebellar Cerebellum The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established... granule cell Granule cell In neuroscience, granule cells refer to tiny neurons that are around 10 micrometres in diameter. Granule cells are found within the granular layer of the cerebellum , the dentate gyrus of the... s |
neurotransmitter Neurotransmitter Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to... release >- | N-type N-type calcium channel The N-type calcium channel is a type of voltage-dependent calcium channel. Like the others of this class, the α1 subunit forms the pore through which calcium enters the cell and determines most of the channel's properties... |
high voltage | Cav2.2 | Throughout the brain Brain The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,... |
neurotransmitter Neurotransmitter Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to... release >- | R-type R-type calcium channel The R-type calcium channel is a type of voltage-dependent calcium channel. Like the others of this class, the α1 subunit forms the pore through which calcium enters the cell and determines most of the channel's properties... |
intermediate voltage | Cav2.3 | Cerebellar Cerebellum The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established... granule cell Granule cell In neuroscience, granule cells refer to tiny neurons that are around 10 micrometres in diameter. Granule cells are found within the granular layer of the cerebellum , the dentate gyrus of the... s, other neurons |
>- | low voltage | Cav3.1 Cav3.2 CACNA1H Calcium channel, voltage-dependent, T type, alpha 1H subunit, also known as CACNA1H, is a protein which in humans is encoded by the CACNA1H gene.- Function :... Cav3.3 |
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neurons, cells that have pacemaker activity, bone (osteocytes) | Regular sinus rhythm Sinus rhythm In medicine, sinus rhythm is the normal beating of the heart, as measured by an electrocardiogram . It has certain generic features that serve as hallmarks for comparison with normal ECGs.- ECG structure :... |
Ligand-gatedLigand-gated ion channelLigand-gated ion channels are one type of ionotropic receptor or channel-linked receptor. They are a group of transmembrane ion channels that are opened or closed in response to the binding of a chemical messenger , such as a neurotransmitter.The binding site of endogenous ligands on LGICs...
- the receptor-operated calcium channels (in vasoconstrictionVasoconstrictionVasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
)- P2X receptorP2X ReceptorP2X receptors are a family of cation-permeable ligand gated ion channels that open in response to the binding of extracellular adenosine 5'-triphosphate . They belong to a larger family of receptors known as the purinergic receptors...
- P2X receptor
| Type | Gated by | Gene | Location | Function >- | IP3 receptor Inositol triphosphate receptor Inositol trisphosphate receptor is a membrane glycoprotein complex acting as Ca2+ channel activated by inositol trisphosphate . InsP3R is very diverse among organisms, and is necessary for the control of cellular and physiological processes including cell division, cell proliferation, apoptosis,... |
IP3 Inositol triphosphate Inositol trisphosphate or inositol 1,4,5-trisphosphate , together with diacylglycerol , is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell... |
ITPR1, ITPR2, ITPR3 | ER Endoplasmic reticulum The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae... /SR |
3 by e.g. GPCRs >- | Ryanodine receptor Ryanodine receptor Ryanodine receptors form a class of intracellular calcium channels in various forms of excitable animal tissue like muscles and neurons... |
dihydropyridine receptors in T-tubule T-tubule A T-tubule is a deep invagination of the sarcolemma, which is the plasma membrane, only found in skeletal and cardiac muscle cells... s and increased intracellular calcium (Calcium Induced Calcium Release - CICR) |
RYR1, RYR2, RYR3 | ER Endoplasmic reticulum The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae... /SR |
Calcium-induced calcium release Calcium-induced calcium release Calcium-induced calcium release is a process whereby calcium can trigger release of further calcium from the muscle sarcoplasmic reticulum. Originally proposed for skeletal muscle in the 1970s, subsequent research has revealed that it is even more pronounced in the cardiac muscle... in myocyte Myocyte A myocyte is the type of cell found in muscles. They arise from myoblasts.Each myocyte contains myofibrils, which are long, long chains of sarcomeres, the contractile units of the cell.... s >- | Two-pore channel Two-pore channel 'Two-pore channels: This small family of 2 members putatively forms cation-selective ion channels. They are predicted to contain two KV-style six-transmembrane domains, suggesting they form a dimer in the membrane. These channels are closely related to CatSper channels and, more distantly, to TRP... |
>- | >- | indirectly by ER Endoplasmic reticulum The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae... /SR depletion of calcium |
ORAI1, ORAI2, ORAI3 | plasma membrane | >- |