CACNA1C: Voltage-sensitive calcium channels (VSCC) 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, gene expression, cell motility, cell division and cell death. The isoform alpha-1C gives rise to L-type calcium currents. Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to omega-conotoxin- GVIA (omega-CTx-GVIA) and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing the alpha-1C subunit play an important role in excitation-contraction coupling in the heart. The various isoforms display marked differences in the sensitivity to DHP compounds. Binding of calmodulin or CABP1 at the same regulatory sites results in an opposit effects on the channel function. Defects in CACNA1C are the cause of Timothy syndrome (TS). TS is a disorder characterized by multiorgan dysfunction including lethal arrhythmias, webbing of fingers and toes, congenital heart disease, immune deficiency, intermittent hypoglycemia, cognitive abnormalities and autism. Defects in CACNA1C are the cause of Brugada syndrome type 3 (BRGDA3). A heart disease characterized by the association of Brugada syndrome with shortened QT intervals. Brugada syndrome is a tachyarrhythmia characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs (called ventricular fibrillation), the individual will faint and may die in a few minutes if the heart is not reset. Belongs to the calcium channel alpha-1 subunit (TC 1.A.1.11) family. CACNA1C subfamily. 35 isoforms of the human protein are produced by alternative splicing.
Protein type: Channel, calcium; Membrane protein, integral; Membrane protein, multi-pass
Chromosomal Location of Human Ortholog: 12p13.33
Cellular Component: cytoplasm; integral component of membrane; L-type voltage-gated calcium channel complex; plasma membrane; postsynaptic density; voltage-gated calcium channel complex; Z disc
Molecular Function: alpha-actinin binding; high voltage-gated calcium channel activity; metal ion binding; protein binding; voltage-gated calcium channel activity; voltage-gated calcium channel activity involved in AV node cell action potential; voltage-gated calcium channel activity involved in cardiac muscle cell action potential
Biological Process: camera-type eye development; cardiac muscle cell action potential involved in contraction; cell communication by electrical coupling involved in cardiac conduction; elevation of cytosolic calcium ion concentration; embryonic forelimb morphogenesis; heart development; immune system development; membrane depolarization during atrial cardiac muscle cell action potential; membrane depolarization during AV node cell action potential; membrane depolarization during cardiac muscle cell action potential; regulation of cardiac muscle contraction by regulation of the release of sequestered calcium ion; regulation of heart rate by cardiac conduction; regulation of insulin secretion; regulation of ventricular cardiac muscle cell action potential
Disease: Brugada Syndrome 3; Timothy Syndrome
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