Target type: molecularfunction
Enables the transmembrane transfer of a calcium ion by a low voltage-gated channel. A low voltage-gated channel is a channel whose open state is dependent on low voltage across the membrane in which it is embedded. [GOC:mtg_transport, ISBN:0815340729, PMID:16382099]
Low-voltage-gated calcium channels (LVGCCs) are a type of voltage-gated calcium channel that are activated by relatively small changes in membrane potential, typically in the range of -50 to -40 mV. They are distinct from high-voltage-gated calcium channels (HVGCCs), which require larger depolarizations to open. LVGCCs play a crucial role in a variety of cellular processes, including:
**1. Excitation-Contraction Coupling in Smooth Muscle:**
LVGCCs are responsible for mediating the influx of calcium ions that triggers contraction in smooth muscle cells. When a smooth muscle cell is stimulated, the depolarization of the membrane opens LVGCCs, allowing calcium to enter the cell and bind to calmodulin. This complex then activates myosin light chain kinase (MLCK), which phosphorylates myosin, enabling it to interact with actin and generate contraction.
**2. Neurotransmitter Release:**
LVGCCs are found in presynaptic terminals of neurons and contribute to the release of neurotransmitters. Upon depolarization, LVGCCs open, allowing calcium influx that triggers the fusion of synaptic vesicles containing neurotransmitters with the presynaptic membrane. This process results in the release of neurotransmitters into the synaptic cleft, where they can bind to receptors on the postsynaptic neuron and transmit signals.
**3. Hormone Secretion:**
Similar to neurotransmitter release, LVGCCs play a role in hormone secretion from endocrine cells. Depolarization of endocrine cells can activate LVGCCs, leading to calcium influx and the subsequent release of hormones, such as insulin from pancreatic beta cells.
**4. Pacemaker Activity:**
LVGCCs are involved in the rhythmic activity of pacemaker cells in the heart and other tissues. In the heart, LVGCCs contribute to the spontaneous depolarization of pacemaker cells, setting the rate of heartbeats.
**5. Sensory Transduction:**
LVGCCs are implicated in sensory transduction processes, such as taste and smell. In taste receptor cells, LVGCCs are activated by specific tastants, contributing to the perception of taste.
**6. Cell Proliferation and Differentiation:**
LVGCCs are involved in regulating cell growth and differentiation. They are implicated in the control of cell cycle progression and the induction of specific developmental pathways.
**7. Neuronal Plasticity:**
LVGCCs contribute to neuronal plasticity, the ability of neurons to change their structure and function in response to experience. They are involved in long-term potentiation (LTP), a mechanism of synaptic strengthening associated with learning and memory.
**8. Modulation of Neuronal Activity:**
LVGCCs can modulate neuronal activity by regulating the release of neurotransmitters, affecting synaptic plasticity, and influencing neuronal excitability.
**9. Gene Expression:**
LVGCCs can influence gene expression by affecting the activity of transcription factors, leading to changes in protein synthesis and cell function.
**10. Cellular Signaling:**
LVGCCs play a role in cellular signaling pathways by initiating calcium signaling cascades, which regulate various cellular processes.
**In summary, low-voltage-gated calcium channels are crucial for a wide range of physiological processes, including muscle contraction, neurotransmitter release, hormone secretion, pacemaker activity, sensory transduction, cell proliferation, neuronal plasticity, and modulation of neuronal activity.**'
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Protein | Definition | Taxonomy |
---|---|---|
Voltage-dependent T-type calcium channel subunit alpha-1H | A voltage-dependent T-type calcium channel subunit alpha-1H that is encoded in the genome of human. [PRO:DNx, UniProtKB:O95180] | Homo sapiens (human) |
Voltage-dependent T-type calcium channel subunit alpha-1G | A voltage-dependent T-type calcium channel subunit alpha-1G that is encoded in the genome of human. [PRO:WCB, UniProtKB:O43497] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
tacrine | tacrine : A member of the class of acridines that is 1,2,3,4-tetrahydroacridine substituted by an amino group at position 9. It is used in the treatment of Alzheimer's disease. Tacrine: A cholinesterase inhibitor that crosses the blood-brain barrier. Tacrine has been used to counter the effects of muscle relaxants, as a respiratory stimulant, and in the treatment of Alzheimer's disease and other central nervous system disorders. | acridines; aromatic amine | EC 3.1.1.7 (acetylcholinesterase) inhibitor |
nimodipine | nimodipine : A dihydropyridine that is 1,4-dihydropyridine which is substituted by methyl groups at positions 2 and 6, a (2-methoxyethoxy)carbonyl group at position 3, a m-nitrophenyl group at position 4, and an isopropoxycarbonyl group at position 5. An L-type calcium channel blocker, it acts particularly on cerebral circulation, and is used both orally and intravenously for the prevention and treatment of subarachnoid hemorrhage from ruptured intracranial aneurysm. Nimodipine: A calcium channel blockader with preferential cerebrovascular activity. It has marked cerebrovascular dilating effects and lowers blood pressure. | 2-methoxyethyl ester; C-nitro compound; dicarboxylic acids and O-substituted derivatives; diester; dihydropyridine; isopropyl ester | antihypertensive agent; calcium channel blocker; cardiovascular drug; vasodilator agent |
pimozide | pimozide : A member of the class of benzimidazoles that is 1,3-dihydro-2H-benzimidazol-2-one in which one of the nitrogens is substituted by a piperidin-4-yl group, which in turn is substituted on the nitrogen by a 4,4-bis(p-fluorophenyl)butyl group. Pimozide: A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403) | benzimidazoles; heteroarylpiperidine; organofluorine compound | antidyskinesia agent; dopaminergic antagonist; first generation antipsychotic; H1-receptor antagonist; serotonergic antagonist |
mibefradil | Mibefradil: A benzimidazoyl-substituted tetraline that selectively binds and inhibits CALCIUM CHANNELS, T-TYPE. | tetralins | T-type calcium channel blocker |
vexibinol | sophoraflavanone G : A tetrahydroxyflavanone having a structure of naringenin bearing an additional hydroxyl substituent at position 2' as well as a (2R)-5-methyl-2-(prop-1-en-2-yl)hex-4-en-1-yl (lavandulyl) substituent at position 8'. vexibinol: flavanol from Sophora; structure in first source; RN given refers to (S-(R*,S*))-isomer | (2S)-flavan-4-one; 4'-hydroxyflavanones; tetrahydroxyflavanone | antimalarial; antimicrobial agent; antioxidant; plant metabolite |
8-prenylnaringenin | 8-prenylnaringenin: a phytogenic antineoplastic agent; structure in first source sophoraflavanone B : A trihydroxyflavanone that is (S)-naringenin having a prenyl group at position 8. | (2S)-flavan-4-one; 4'-hydroxyflavanones; trihydroxyflavanone | plant metabolite; platelet aggregation inhibitor |
flunarizine | Flunarizine: Flunarizine is a selective calcium entry blocker with calmodulin binding properties and histamine H1 blocking activity. It is effective in the prophylaxis of migraine, occlusive peripheral vascular disease, vertigo of central and peripheral origin, and as an adjuvant in the therapy of epilepsy. | diarylmethane | |
2-phenoxy-N-[5-(5,6,7,8-tetrahydronaphthalen-2-yl)-1,3,4-oxadiazol-2-yl]acetamide | tetralins | ||
(S)-4',5,7-Trihydroxy-6-prenylflavanone | flavanones | ||
np 118809 | 1-(4-benzhydrylpiperazin-1-yl)-3,3-diphenylpropan-1-one: an N-type calcium channel blocker; structure in first source | ||
cilnidipine | 2-methoxyethyl ester; C-nitro compound; dihydropyridine | antihypertensive agent; calcium channel blocker; cardiovascular drug | |
ith 4012 | |||
NNC 55-0396 (free base) | benzimidazoles; cyclopropanecarboxylate ester; organofluorine compound; tertiary amino compound; tetralins | angiogenesis inhibitor; antineoplastic agent; apoptosis inducer; neuroprotective agent; potassium channel blocker; T-type calcium channel blocker | |
nnc 55-0396 | NNC 55-0396 dihydrochloride : The dihydrochloride salt of NNC 55-0396. It is a stable analogue of mibefradil and a highly selective T-type calcium channel blocker. NNC 55-0396: a calcium channel blocker with high selectivity for CaV3 channels over high voltage activated channels; structure in first source | hydrochloride | angiogenesis inhibitor; antineoplastic agent; apoptosis inducer; neuroprotective agent; potassium channel blocker; T-type calcium channel blocker |
kys 05090 | |||
ulixacaltamide | Z944: a T-type calcium channel antagonist | benzamides; monochlorobenzenes; monofluorobenzenes; piperidines; secondary carboxamide | non-narcotic analgesic; T-type calcium channel blocker |