Each subunit contains six transmembrane segments (S1-S6) with S1-S4 forming one voltage sensing domain (VSD) and S5-S6 contributing to form one quarter of an interlocking pore-forming domain (PD).
The S4-S5 linker preferentially interacts with PIP2 in the open-state KCNQ2 channel, whereas the S2-S3 loop interacts with PIP2 in the closed state.
The intracellular C-terminal domain is bound constitutively by calmodulin (CaM) (PubMed:27564677, PubMed:32884139, PubMed:37857637). This domain plays key functions in channel tetramerization, trafficking, and gating (PubMed:27564677).
Pore-forming subunit of the voltage-gated potassium (Kv) M-channel which is responsible for the M-current, a key controller of neuronal excitability (PubMed:24277843, PubMed:28793216, PubMed:9836639). M-channel is composed of pore-forming subunits KCNQ2 and KCNQ3 assembled as heterotetramers (PubMed:10781098, PubMed:14534157, PubMed:32884139, PubMed:37857637, PubMed:9836639). 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 (PubMed:14534157, PubMed:28793216, PubMed:9836639). KCNQ2-KCNQ3 M-channel is selectively permeable in vitro to other cations besides potassium, in decreasing order of affinity K(+) > Rb(+) > Cs(+) > Na(+) (PubMed:28793216). M-channel association with SLC5A3/SMIT1 alters channel ion selectivity, increasing Na(+) and Cs(+) permeation relative to K(+) (PubMed:28793216). Suppressed by activation of the muscarinic acetylcholine receptor CHRM1 (PubMed:10684873, PubMed:10713961).
Seizures, benign familial neonatal 1
BFNS1
A disorder characterized by clusters of seizures occurring in the first days of life. Most patients have spontaneous remission by 12 months of age and show normal psychomotor development. Some rare cases manifest an atypical severe phenotype associated with epileptic encephalopathy and psychomotor retardation. The disorder is distinguished from benign familial infantile seizures by an earlier age at onset. In some patients, neonatal convulsions are followed later in life by myokymia, a benign condition characterized by spontaneous involuntary contractions of skeletal muscles fiber groups that can be observed as vermiform movement of the overlying skin. Electromyography typically shows continuous motor unit activity with spontaneous oligo- and multiplet-discharges of high intraburst frequency (myokymic discharges). Some patients may have isolated myokymia.
None
The disease is caused by variants affecting the gene represented in this entry.
Developmental and epileptic encephalopathy 7
DEE7
An autosomal dominant seizure disorder characterized by infantile onset of refractory seizures with resultant delayed neurologic development and persistent neurologic abnormalities.
None
The disease is caused by variants affecting the gene represented in this entry.
KCNQ2/KCNQ3 heteromeric current can be increased by intracellular cyclic AMP, an effect that depends on phosphorylation of Ser-52 in the N-terminal region.
KCNQ2/KCNQ3 are ubiquitinated by NEDD4L. Ubiquitination leads to protein degradation (Probable). Degradation induced by NEDD4L is inhibited by USP36 (PubMed:27445338).
Belongs to the potassium channel family. KQT (TC 1.A.1.15) subfamily. Kv7.2/KCNQ2 sub-subfamily.
In adult and fetal brain. Highly expressed in areas containing neuronal cell bodies, low in spinal cord and corpus callosum. Isoform 2 is preferentially expressed in differentiated neurons. Isoform 6 is prominent in fetal brain, undifferentiated neuroblastoma cells and brain tumors.
Potassium voltage-gated channel subfamily KQT member 2, KQT-like 2, Neuroblastoma-specific potassium channel subunit alpha KvLQT2, Voltage-gated potassium channel subunit Kv7.2, KCNQ2
Proteins
Neuroscience
95848Da
We found 1 product in 1 category