CACNA1IA gene on chromosome 22q13.1 that encodes the alpha-1I subunit of a voltage-dependent calcium channel, which mediates the entry of calcium ions into excitable cells. These channels are also involved in various calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and apoptosis. CACNA1I gives rise to T-type calcium channels that belong to the low-voltage activated (LVA) group, which are remarkable for opening at very negative potentials and for voltage-dependent inactivation. T-type channels are pacemakers for both central neurons and cardiac nodal cells, and support calcium signalling in secretory cells and vascular smooth muscle. They may be involved in modulating firing patterns of neurons, which is key to information processing as well as cell growth.
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