Pore-forming, alpha-1C subunit of the voltage-gated calcium channel that gives rise to L-type calcium currents (PubMed:8392192, PubMed:7737988, PubMed:9087614, PubMed:9013606, PubMed:9607315, PubMed:12176756, PubMed:17071743, PubMed:11741969, PubMed:8099908, PubMed:12181424, PubMed:29078335, PubMed:29742403, PubMed:16299511, PubMed:20953164, PubMed:15454078, PubMed:15863612, PubMed:17224476, PubMed:24728418, PubMed:26253506, PubMed:27218670, PubMed:23677916). Mediates influx of calcium ions into the cytoplasm, and thereby triggers calcium release from the sarcoplasm (By similarity). Plays an important role in excitation-contraction coupling in the heart. Required for normal heart development and normal regulation of heart rhythm (PubMed:15454078, PubMed:15863612, PubMed:17224476, PubMed:24728418, PubMed:26253506). Required for normal contraction of smooth muscle cells in blood vessels and in the intestine. Essential for normal blood pressure regulation via its role in the contraction of arterial smooth muscle cells (PubMed:28119464). Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group (Probable). (Microbial infection) Acts as a receptor for Influenzavirus (PubMed:29779930). May play a critical role in allowing virus entry when sialylated and expressed on lung tissues (PubMed:29779930). Inhibited by dihydropyridines (DHP), such as isradipine (PubMed:8392192, PubMed:7737988, PubMed:9607315, PubMed:8099908). Inhibited by nifedipine (By similarity). Channel activity is regulated by Ca(2+) and calmodulin (PubMed:29742403) (Probable). Binding of STAC1, STAC2 or STAC3 to a region that overlaps with the calmodulin binding site inhibits channel inactivation by Ca(2+) and calmodulin (PubMed:29078335). Binding of calmodulin or CABP1 at the same regulatory sites results in opposite effects on the channel function (PubMed:15140941, PubMed:15980432). Shear stress and pressure increases calcium channel activity (PubMed:12176756). Component of a calcium channel complex consisting of a pore-forming alpha subunit (CACNA1C) and ancillary beta, gamma and delta subunits (PubMed:12181424, PubMed:12176756, PubMed:29742403, PubMed:29078335, PubMed:15141227, PubMed:16299511, PubMed:20953164). The channel complex contains alpha, beta, gamma and delta subunits in a 1:1:1:1 ratio, i.e. it contains only one of each type of subunit (Probable). CACNA1C channel activity is modulated by ancillary subunits, such as CACNB1, CACNB2, CACNB3, CACNA2D1 and CACNA2D4 (PubMed:11741969, PubMed:12181424, PubMed:29742403, PubMed:17224476). Interacts with the gamma subunits CACNG4, CACNG6, CACNG7 and CACNG8 (By similarity). Interacts with CACNB1 (By similarity). Interacts with CACNB2 (PubMed:12176756, PubMed:11741969, PubMed:29742403, PubMed:15141227, PubMed:20953164, PubMed:15863612, PubMed:17224476, PubMed:24728418). Identified in a complex with CACNA2D4 and CACNB3 (PubMed:12181424). Interacts with CACNB3 (PubMed:12181424, PubMed:29742403). Interacts with CACNA2D1 (PubMed:29742403, PubMed:20953164, PubMed:15863612, PubMed:24728418). Interacts with CACNA2D4 (PubMed:12181424). Interacts with CALM1 (PubMed:29742403, PubMed:16299511, PubMed:16338416, PubMed:19279214, PubMed:20953164, PubMed:22518098). Interacts (via the N-terminus and the C-terminal C and IQ motifs) with CABP1; this inhibits Ca(2+)-dependent channel inactivation (PubMed:15140941, PubMed:15980432). The binding via the C motif is calcium independent whereas the binding via IQ requires the presence of calcium and is mutually exclusive with calmodulin binding (PubMed:15140941). The binding to the cytoplasmic N-terminal domain is calcium independent but is essential for the channel modulation. Interacts (via C-terminal CDB motif) with CABP5; in a calcium-dependent manner (By similarity). Interacts with CIB1; the interaction increases upon cardiomyocytes hypertrophy (By similarity). Interacts with STAC2 and STAC3; this inhibits channel inactivation (PubMed:29078335). (Microbial infection) Interacts with influenzavirus H1 hemagglutinin. Colocalizes with ryanodine receptors in distinct clusters at the junctional membrane, where the sarcolemma and the sarcoplasmic reticulum are in close contact. The interaction between RRAD and CACNB2 promotes the expression of CACNA1C at the cell membrane. Additional isoforms seem to exist. Exons 8A, 21, 22, 31, 32, 33, 40B, 43A, 41A and 45 are alternatively spliced in a variety of combinations. Experimental confirmation may be lacking for some isoforms. Detected throughout the brain, including hippocampus, cerebellum and amygdala, throughout the heart and vascular system, including ductus arteriosus, in urinary bladder, and in retina and sclera in the eye (PubMed:15454078). Expressed in brain, heart, jejunum, ovary, pancreatic beta-cells and vascular smooth muscle. Overall expression is reduced in atherosclerotic vascular smooth muscle. Each of the four internal repeats contains five hydrophobic transmembrane segments (S1, S2, S3, S5, S6) and one positively charged transmembrane segment (S4). S4 segments probably represent the voltage-sensor and are characterized by a series of positively charged amino acids at every third position. Binding of intracellular calcium through the EF-hand motif inhibits the opening of the channel. Phosphorylation by PKA at Ser-1981 activates the channel. Elevated levels of blood glucose lead to increased phosphorylation by PKA. The disease is caused by variants affecting the gene represented in this entry. The gene represented in this entry may be involved in disease pathogenesis. The disease is caused by variants affecting the gene represented in this entry. Contains exon 8a. Lacks exon 21. Lacks exon 22. Lacks exon 31. Lacks exon 32. Lacks exon 33. Contains exon 40B and 43A. Contains exon 41A. Lacks exon 45. Predominant isoform in atherosclerotic vascular smooth muscle cells. Not inhibited by calcium. Enhanced by PKC activator. Belongs to the calcium channel alpha-1 subunit (TC 1.A.1.11) family. CACNA1C subfamily.