ID:KCNQ2_HUMAN DESCRIPTION: RecName: Full=Potassium voltage-gated channel subfamily KQT member 2; AltName: Full=KQT-like 2; AltName: Full=Neuroblastoma-specific potassium channel subunit alpha KvLQT2; AltName: Full=Voltage-gated potassium channel subunit Kv7.2; FUNCTION: Probably important in the regulation of neuronal excitability. Associates with KCNQ3 to form a potassium channel with essentially identical properties to the channel underlying the native M-current, 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. KCNQ2/KCNQ3 current is blocked by linopirdine and XE991, and activated by the anticonvulsant retigabine. Muscarinic agonist oxotremorine-M strongly suppress KCNQ2/KCNQ3 current in cells in which cloned KCNQ2/KCNQ3 channels were coexpressed with M1 muscarinic receptors. SUBUNIT: Heteromultimer with KCNQ3. May associate with KCNE2. SUBCELLULAR LOCATION: Membrane; Multi-pass membrane protein. TISSUE SPECIFICITY: In adult and fetal brain. Highly expressed in areas containing neuronal cell bodies, low in spinal chord and corpus callosum. Isoform 2 is preferentially expressed in differentiated neurons. Isoform 6 is prominent in fetal brain, undifferentiated neuroblastoma cells and brain tumors. DOMAIN: The segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position (By similarity). PTM: In Xenopus oocytes KCNQ2/KCNQ3 heteromeric current can be increased by intracellular cyclic AMP, an effect that depends on phosphorylation of Ser-52 in the N-terminus region. DISEASE: Defects in KCNQ2 are the cause of benign familial neonatal seizures type 1 (BFNS1) [MIM:121200]. 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. DISEASE: Defects in KCNQ2 are the cause of epileptic encephalopathy early infantile type 7 (EIEE7) [MIM:613720]. EIEE7 is an autosomal dominant seizure disorder characterized by infantile onset of refractory seizures with resultant delayed neurologic development and persistent neurologic abnormalities. MISCELLANEOUS: Inclusion of isoform 6 in heteromultimers results in attenuation of potassium current. Prominent expression of isoform 6 in the developing brain may alter firing repertoires of immature neurons excitability to provide cues for proliferation rather than differentiation. MISCELLANEOUS: Mutagenesis experiments were carried out in Xenopus oocytes by coexpression of either KCNQ2(mut) and KCNQ3 at the ratio of 1:1, or of KCNQ2(mut), KCNQ2(wt) and KCNQ3 at the ratio of 1:1:2, to mimic the situation in a heterozygous patient with BFNC1 disease. SIMILARITY: Belongs to the potassium channel family. KQT (TC 1.A.1.15) subfamily. Kv7.2/KCNQ2 sub-subfamily. WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/KCNQ2";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
Pfam Domains: PF00520 - Ion transport protein PF03520 - KCNQ voltage-gated potassium channel PF07885 - Ion channel PF11956 - Ankyrin-G binding motif of KCNQ2-3 PF16642 - Unstructured region on Potassium channel subunit alpha KvLQT2
ModBase Predicted Comparative 3D Structure on O43526
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Biological Process: GO:0006811 ion transport GO:0006813 potassium ion transport GO:0007268 chemical synaptic transmission GO:0007399 nervous system development GO:0034765 regulation of ion transmembrane transport GO:0055085 transmembrane transport GO:0071805 potassium ion transmembrane transport
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Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
