FunctionProbably important in the regulation of neuronal excitability. May underlie a potassium current involved in regulating the excitability of sensory cells of the cochlea. KCNQ4 channels are blocked by linopirdin, XE991 and bepridil, whereas clofilium is without significant effect. Muscarinic agonist oxotremorine-M strongly suppress KCNQ4 current in CHO cells in which cloned KCNQ4 channels were coexpressed with M1 muscarinnic receptors.
Tissue specificityExpressed in the outer, but not the inner, sensory hair cells of the cochlea. Slightly expressed in heart, brain and skeletal muscle.
Involvement in diseaseDefects in KCNQ4 are the cause of deafness autosomal dominant type 2A (DFNA2A) [MIM:600101]. DFNA2A is a form of sensorineural hearing loss. Sensorineural deafness results from damage to the neural receptors of the inner ear, the nerve pathways to the brain, or the area of the brain that receives sound information.
Sequence similaritiesBelongs to the potassium channel family. KQT (TC 1.A.1.15) subfamily. Kv7.4/KCNQ4 sub-subfamily.
DomainThe segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position. The A-domain tail carries the major determinants of channel assembly specificity. Its coiled-coil region is Four-stranded.
Cellular localizationBasal cell membrane. Situated at the basal membrane of cochlear outer hair cells.