Potassium voltage-gated channel, shaker-related subfamily, member 5, also known as KCNA5 or K
v1.5, 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 ''KCNA5''
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
Potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of ...
s represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. KCNA5 encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, the function of which could restore the resting
membrane potential
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. It equals the interior potential minus the exterior potential. This is th ...
of
beta cell
Beta cells (β-cells) are specialized endocrine cells located within the pancreatic islets of Langerhans responsible for the production and release of insulin and amylin. Constituting ~50–70% of cells in human islets, beta cells play a vi ...
s after depolarization, thereby contributing to the regulation of
insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (''INS)'' gene. It is the main Anabolism, anabolic hormone of the body. It regulates the metabol ...
secretion. This gene is
intron
An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e., a region inside a gene."The notion of the cistron .e., gen ...
less, and the gene is clustered with genes
KCNA1 and
KCNA6 on chromosome 12.
Mutations in this gene have been related to both
atrial fibrillation
Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...
and sudden cardiac death.
KCNA5 are also key players in pulmonary vascular function, where they play a role in setting the resting membrane potential and its involvement during hypoxic pulmonary vasoconstriction.
Interactions
KCNA5 has been shown to
interact with
DLG4
PSD-95 (postsynaptic density protein 95) also known as SAP-90 (synapse-associated protein 90) is a protein that in humans is encoded by the ''DLG4'' (discs large homolog 4) gene.
PSD-95 is a member of the membrane-associated guanylate kinase (MA ...
,
PDZ domain-containing proteins such as SAP97,
and
Actinin, alpha 2.
See also
* Voltage-gated potassium channel
Voltage-gated potassium channels (VGKCs) are potassium channel, transmembrane channels specific for potassium and Voltage-gated ion channel, sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a ...
References
Further reading
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External links
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Ion channels
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