Cav1.2

Calcium channel, voltage-dependent, L type, alpha 1C subunit (also known as Cav1.2) is a is_associated_with::protein that in humans is encoded by the CACNA1C is_associated_with::gene. Cav1.2 is a subunit of L-type is_associated_with::voltage-dependent calcium channel.

Structure and function
This gene encodes an alpha-1 subunit of a voltage-dependent calcium channel. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization. The alpha-1 subunit consists of 24 transmembrane segments and forms the pore through which ions pass into the cell. The calcium channel consists of a complex of alpha-1, alpha-2/delta and beta subunits in a 1:1:1 ratio. Cav1.2 is widely expressed, however it is particularly important and well known for its expression in the heart where it mediates L-type currents, which causes calcium-induced calcium release from the ER Stores via ryanodine receptors. The protein encoded by this gene binds to and is inhibited by is_associated_with::dihydropyridine. In the arteries of the brain, high levels of calcium in mitochondria elevates activity of nuclear factor kappa B is_associated_with::NF-κB and transcription of CACNA1c and functional Cav1.2 expression increases. Cav1.2 also regulates levels of is_associated_with::osteoprotegerin.

CaV1.2 is inhibited by the action of is_associated_with::STIM1.

Clinical significance
Mutation in the CACNA1C gene are associated with a variant of is_associated_with::Long QT syndrome called is_associated_with::Timothy's syndrome and also with is_associated_with::Brugada syndrome. A large-scale genetic analysis conducted in 2008 shows the possibility that CACNA1C is associated with is_associated_with::bipolar disorder and subsequently also with is_associated_with::schizophrenia. Also, CACNA1C A risk allele has been associated to a disruption in brain connectivity in patients with bipolar disorder, while not or only to a minor degree, in their unaffected relatives or healthy controls.