Potassium voltage-gated channel subfamily S member 3 (Kv9.3) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''KCNS3''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. KCNS3 gene belongs to the S subfamily of the potassium channel family. It is highly expressed in

pulmonary artery A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and t ...

myocyte A muscle cell is also known as a myocyte when referring to either a cardiac muscle cell (cardiomyocyte), or a smooth muscle cell as these are both small cells. A skeletal muscle cell is long and threadlike with many nuclei and is called a muscl ...

placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mater ...

, and

parvalbumin Parvalbumin (PV) is a calcium-binding protein with low molecular weight (typically 9-11 kDa). In humans, it is encoded by the ''PVALB'' gene. It is not a member of the albumin family; it is named for its size (''parv-'', from Latin ''parvus'' smal ...

-containing GABA

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

s in brain cortex. In humans, single-nucleotide polymorphisms of the KCNS3 gene are associated with

airway hyperresponsiveness Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity, BH used as a general abbreviation) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways). Bronchial hyperresp ...

, whereas decreased KCNS3 mRNA expression is found in the

prefrontal cortex In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, ...

of patients with

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...

Function

Voltage-gated potassium channels form the largest and most diversified class of ion channels and are present in both excitable and nonexcitable cells. Their main functions are associated with the regulation of the resting membrane potential and the control of the shape and frequency of action potentials. The alpha subunits are of 2 types: those that are functional by themselves and those that are electrically silent but capable of modulating the activity of specific functional alpha subunits. The Kv9.3 protein (encoded by KCNS3 gene) is not functional by itself but can form functional heteromultimers with Kv2.1 (encoded by

KCNB1 Potassium voltage-gated channel, Shab-related subfamily, member 1, also known as KCNB1 or Kv2.1, is a protein that, in humans, is encoded by the ''KCNB1'' gene. Potassium voltage-gated channel subfamily B member one, or simply known as KCNB1, is ...

) and Kv2.2 (encoded by

KCNB2 Potassium voltage-gated channel subfamily B member 2 is a protein that in humans is encoded by the ''KCNB2'' gene. The protein encoded by this gene is a voltage-gated potassium channel subunit. Research Limited research has been performed for ...

) (and possibly other members) of the Shab-related subfamily of potassium voltage-gated channel proteins. Heteromeric Kv2.1/Kv9.3 channels form with fixed stoichiometry consisting of three Kv2.1 subunits and one Kv9.3 subunit.

References

Ion channels {{membrane-protein-stub

Function

See also

References