KCNMB4
Description
The KCNMB4 (potassium calcium-activated channel subfamily M regulatory beta subunit 4) is a protein-coding gene located on chromosome 12.
KCNMB4 (Calcium-activated potassium channel subunit beta-4) is a protein encoded by the KCNMB4 gene in humans. It is an auxiliary beta subunit of MaxiK channels, large conductance, voltage and calcium-sensitive potassium channels crucial for regulating smooth muscle tone and neuronal excitability. KCNMB4 slows activation kinetics, increases calcium sensitivity, and shifts the voltage range of current activation to more negative potentials compared to the beta 1 subunit. MaxiK channels are formed by two subunits: the pore-forming alpha subunit and the modulatory beta subunit.
KCNMB4 is a regulatory subunit of the calcium-activated potassium channel KCNMA1 (maxiK). It modulates the calcium sensitivity and gating kinetics of KCNMA1, contributing to its diversity. KCNMB4 decreases the gating kinetics and calcium sensitivity of KCNMA1, but with fast deactivation kinetics. It may decrease KCNMA1 channel openings at low calcium concentrations but increases channel openings at high calcium concentrations. KCNMB4 makes KCNMA1 channels resistant to 100 nM charybdotoxin (CTX) toxin concentrations.
KCNMB4 is also known as -.
Associated Diseases
- juvenile myoclonic epilepsy
- childhood absence epilepsy
- intellectual disability, autosomal dominant 10
- generalized epilepsy with febrile seizures plus, type 7
- developmental and epileptic encephalopathy, 9
- generalized epilepsy with febrile seizures plus, type 2
- developmental and epileptic encephalopathy, 19
- juvenile absence epilepsy
- benign familial infantile epilepsy
- Dravet syndrome
- schizophrenia 15
