KCNQ3 : potassium voltage-gated channel subfamily Q member 3
Description
The KCNQ3 (potassium voltage-gated channel subfamily Q member 3) is a protein-coding gene located on chromosome 8.
The KCNQ3 gene produces instructions for creating potassium channels, which are crucial for cell signaling. KCNQ3 channels reside in brain neurons and transport potassium ions out of cells, generating the M-current. This current ensures that neurons are not constantly active. KCNQ3 channels can be formed by four KCNQ3 protein subunits or by a combination of KCNQ3 and KCNQ2 subunits, which produce a stronger M-current.
KCNQ3 forms potassium channels with similar properties to the native M-current, a slow-acting potassium conductance crucial for regulating neuron excitability and responsiveness to synaptic inputs. It partners with KCNQ2 or KCNQ5, creating channels with identical M-current features. The KCNQ2-KCNQ3 channel exhibits selective permeability to potassium and other cations, with decreasing affinity for rubidium, cesium, and sodium. It forms a coregulatory complex with SLC5A3, a sodium-coupled myo-inositol symporter, which modifies ion selectivity, enhancing sodium and cesium permeability relative to potassium.
KCNQ3 is also known as BFNC2, EBN2, KV7.3.
Associated Diseases
- Benign familial neonatal epilepsy
- Epilepsy, benign neonatal, 2
- Juvenile myoclonic epilepsy
- Benign familial infantile epilepsy
- Benign familial neonatal seizures
