K+ voltage-gated channel subfamily KQT member 4; KQT-like 4; K+ channel subunit alpha KvLQT4; voltage-gated K+ channel subunit Kv7.4 (KCNQ4)

Function

• role in regulation of neuronal excitability (putative)
• may underlie a K+ current involved in regulating the excitability of sensory cells of the cochlea
• KCNQ4 channels are blocked by linopirdin, XE991 & 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
• may form heteromultimers with KCNQ3

Structure

• the segment S4 is probably the voltage-sensor & is characterized by a series of positively charged amino acids at every third position (putative)
• belongs to the K+ channel family, KQT (TC 1.A.1.15) subfamily, Kv7.4/KCNQ4 sub-subfamily

Compartment

• basal cell membrane; multi-pass membrane protein
• situated at the basal membrane of cochlear outer hair cells (putative)

Alternative splicing

• named isoforms=2
• additional isoforms seem to exist

Expression

• expressed in the outer sensory hair cells of the cochlea
• not expressed in the inner sensory hair cells of the cochlea
• low expression in heart, brain & skeletal muscle

Pathology

• defects in KCNQ4 are the cause of autosomal dominant deafness type 2A

More general terms

• transmembrane 6 protein
• K+ channel subfamily KQT

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9132
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9132
• OMIM: https://mirror.omim.org/entry/600101
• OMIM: https://mirror.omim.org/entry/603537
• UniProt: http://www.uniprot.org/uniprot/P56696.html