Summary
Performance
Immunogen
Application
Background
MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit. The protein encoded by this gene is an auxiliary beta subunit which slows activation kinetics, leads to steeper calcium sensitivity, and shifts the voltage range of current activation to more negative potentials than does the beta 1 subunit. [provided by RefSeq, Jul 2008],domain:Resistance to charybdotoxin (CTX) toxin is mediated by the extracellular domain.,function:Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. Decreases the gating kinetics and calcium sensitivity of the KCNMA1 channel, but with fast deactivation kinetics. May decrease KCNMA1 channel openings at low calcium concentrations but increases channel openings at high calcium concentrations. Makes KCNMA1 channel resistant to 100 nM charybdotoxin (CTX) toxin concentrations.,miscellaneous:Treatment with okadaic acid reduces its effect on KCNMA1.,PTM:N-glycosylated. A highly glycosylated form is promoted by KCNMA1. Glycosylation, which is not required for the interaction with KCNMA1 and subcellular location, increases protection against charybdotoxin.,PTM:Phosphorylated. Phosphorylation modulates its effect on KCNMA1 activation kinetics.,similarity:Belongs to the KCNMB family.,subunit:Interacts with KCNMA1 tetramer. There are probably 4 molecules of KCMNB4 per KCNMA1 tetramer.,tissue specificity:Predominantly expressed in brain. In brain, it is expressed in the cerebellum, cerebral cortex, medulla, spinal cord, occipital pole, frontal lobe, temporal lobe, putamen, amygdala, caudate nucleus, corpus callosum, hippocampus, substantia nigra and thalamus. Weakly or not expressed in other tissues.,
Research Area
Vascular smooth muscle contraction;
