Voltage-dependent L-type calcium channel subunit beta-4 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''CACNB4''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
This gene encodes a member of the beta subunit family, a protein in the voltage-dependent
calcium channel
A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, which are a type of calcium channel regulated by changes in membrane potential. Some calcium chan ...
complex. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. Various versions of each of these subunits exist, either expressed from similar genes or the result of
alternative splicing
Alternative splicing, alternative RNA splicing, or differential splicing, is an alternative RNA splicing, splicing process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene ma ...
. The protein described in this record plays an important role in calcium channel function by modulating
G protein
G proteins, also known as guanine nucleotide-binding proteins, are a Protein family, family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell (biology), ...
inhibition, increasing peak calcium current, controlling the alpha-1 subunit membrane targeting and shifting the voltage dependence of activation and inactivation. Alternate transcriptional splice variants of this gene, encoding different isoforms, have been characterized.
Clinical significance
Certain mutations in this gene have been associated with
idiopathic generalized epilepsy (IGE) and
juvenile myoclonic epilepsy (JME).
Interactions
CACNB4 has been shown to
interact with
Cav2.1.
See also
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Voltage-dependent calcium channel
Voltage-gated calcium channels (VGCCs), also known as voltage-dependent calcium channels (VDCCs), are a group of voltage-gated ion channels found in the membrane of excitable cells (''e.g.'' muscle, glial cells, neurons) with a permeability t ...
References
Further reading
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External links
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Ion channels
{{Membrane-protein-stub