Potassium voltage-gated channel subfamily KQT member 3

UniProt O43525 Organism Homo sapiens Gene KCNQ3

Also known as: KCNQ3

Function

Pore-forming subunit of the voltage-gated potassium (Kv) M-channel which is responsible for the M-current, a key controller of neuronal excitability. M-channel is composed of pore-forming subunits KCNQ2 and KCNQ3 assembled as heterotetramers. The native M-current has a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs. M-channel is selectively permeable in vitro to other cations besides potassium, in decreasing order of affinity K(+) > Rb(+) > Cs(+) > Na(+). M-channel association with SLC5A3/SMIT1 alters channel ion selectivity, increasing Na(+) and Cs(+) permeation relative to K(+). Suppressed by activation of M1 muscarinic acetylcholine receptors. KCNQ3 also associates with KCNQ5 to form a functional channel in vitro and may also contribute to the M-current in brain.

Classification

Family (Pfam): PF00520 Ion_trans, PF03520 KCNQ_channel, PF11956 KCNQC3-Ank-G_bd
InterPro: Ankyrin-G_BS, Ion_trans_dom, K_chnl_volt-dep_KCNQ, K_chnl_volt-dep_KCNQ3, K_chnl_volt-dep_KCNQ_C
Functional cluster: RRM RNA-Binding & Protein Kinases

Experimental structures · PDB · 1

5J03 X-ray 2.00A

A predicted model is available from AlphaFold.

Gene Ontology · 11

Disease associations

seizures, benign familial neonatal, 2 MONDO:0007366

Drugs targeting this protein · 8

Related proteins · sequence + function similarity

Co-cited proteins · studied together in the literature

Potassium voltage-gated channel subfamily KQT member 2 16 shared papers
Potassium voltage-gated channel subfamily KQT member 5 1 shared papers
Sodium channel protein type 2 subunit alpha 3 shared papers
Potassium voltage-gated channel subfamily KQT member 2 1 shared papers
Sodium/myo-inositol cotransporter 1 shared papers
Potassium voltage-gated channel subfamily E member 2 1 shared papers
Potassium voltage-gated channel subfamily KQT member 4 1 shared papers
Spermine synthase 1 shared papers
Ubiquitin carboxyl-terminal hydrolase 36 1 shared papers
Rho guanine nucleotide exchange factor 9 1 shared papers
Potassium voltage-gated channel subfamily KQT member 1 1 shared papers
Major facilitator superfamily domain-containing protein 8 1 shared papers

Literature · 23 cited papers

SMIT1 Modifies KCNQ Channel Function and Pharmacology by Physical Interaction with the Pore. Biophys. J. · 2017
Structural insights into the M-channel proximal C-terminus/calmodulin complex. Biochemistry · 2016
Ubiquitin-specific Protease 36 (USP36) Controls Neuronal Precursor Cell-expressed Developmentally Down-regulated 4-2 (Nedd4-2) Actions over the Neurotrophin Receptor TrkA and Potassium Voltage-gated Channels 7.2/3 (Kv7.2/3). J. Biol. Chem. · 2016
Familial neonatal seizures in 36 families: Clinical and genetic features correlate with outcome. Epilepsia · 2015
Genetic testing in benign familial epilepsies of the first year of life: clinical and diagnostic significance. Epilepsia · 2013
Targeted next generation sequencing as a diagnostic tool in epileptic disorders. Epilepsia · 2012
DNA sequence and analysis of human chromosome 8. Nature · 2006
Identification by mass spectrometry and functional characterization of two phosphorylation sites of KCNQ2/KCNQ3 channels. Proc. Natl. Acad. Sci. U.S.A. · 2005
The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. · 2004
Complete sequencing and characterization of 21,243 full-length human cDNAs. Nat. Genet. · 2004
KCNQ2 and KCNQ3 potassium channel genes in benign familial neonatal convulsions: expansion of the functional and mutation spectrum. Brain · 2003
Characterization of KCNQ5/Q3 potassium channels expressed in mammalian cells. Br. J. Pharmacol. · 2001
… and 11 more in the literature graph

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