KCNQ5

This gene is a member of the KCNQ potassium channel gene family that is differentially expressed in subregions of the brain and in skeletal muscle. The protein encoded by this gene yields currents that activate slowly with depolarization and can form heteromeric channels with the protein encoded by the KCNQ3 gene. Currents expressed from this protein have voltage dependences and inhibitor sensitivities in common with M-currents. They are also inhibited by M1 muscarinic receptor activation. Multiple transcript variants encoding different isoforms have been found for this gene.

Full Name

potassium voltage-gated channel subfamily Q member 5

Function

Associates with KCNQ3 to form a potassium channel which contributes to M-type current, a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons. Therefore, it is important in the regulation of neuronal excitability. May contribute, with other potassium channels, to the molecular diversity of a heterogeneous population of M-channels, varying in kinetic and pharmacological properties, which underlie this physiologically important current. Insensitive to tetraethylammonium, but inhibited by barium, linopirdine and XE991. Activated by niflumic acid and the anticonvulsant retigabine. As the native M-channel, the potassium channel composed of KCNQ3 and KCNQ5 is also suppressed by activation of the muscarinic acetylcholine receptor CHRM1.

Biological Process

Potassium ion transmembrane transportManual Assertion Based On ExperimentIDA:UniProtKB
Regulation of ion transmembrane transportIEA:UniProtKB-KW

Cellular Location

Cell membrane

Involvement in disease

Mental retardation, autosomal dominant 46 (MRD46):
A form of mental retardation, a disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period. MRD46 patients manifest developmental delay and mild to moderate intellectual disability.

Topology

Cytoplasmic: 1-125
Helical: 126-146
Extracellular: 147-156
Helical: 157-177
Cytoplasmic: 178-200
Helical: 201-221
Extracellular: 222-229
Helical: 230-252
Cytoplasmic: 253-266
Helical: 267-287
Extracellular: 288-298
Pore-forming: 299-319
Extracellular: 320-325
Helical: 326-346
Cytoplasmic: 347-932