KCNMB4 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. Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB4 subfamily. 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. Note: This description may include information from UniProtKB.
Protein type: Channel, potassium; Membrane protein, integral; Membrane protein, multi-pass
Chromosomal Location of human Ortholog: 12q15
Cellular Component:  plasma membrane; synapse; voltage-gated potassium channel complex
Molecular Function:  calcium-activated potassium channel activity; potassium channel regulator activity; protein binding; voltage-gated monoatomic ion channel activity involved in regulation of presynaptic membrane potential
Biological Process:  action potential; chemical synaptic transmission; detection of calcium ion; neuronal action potential; potassium ion transmembrane transport; potassium ion transport; regulation of neurotransmitter secretion; regulation of presynaptic membrane potential; regulation of vasoconstriction
Reference #:  Q86W47 (UniProtKB)
Alt. Names/Synonyms: big potassium channel beta subunit 4; BK channel beta subunit 4; BK channel subunit beta-4; BKbeta4; Calcium-activated potassium channel subunit beta-4; Calcium-activated potassium channel, subfamily M subunit beta-4; Charybdotoxin receptor subunit beta-4; Hbeta4; K(VCA)beta-4; KCMB4; KCNMB4; large conductance calcium-dependent potassium ion channel beta 4 subunit; Maxi K channel subunit beta-4; MaxiK channel beta-subunit 4; potassium calcium-activated channel subfamily M regulatory beta subunit 4; potassium channel subfamily M regulatory beta subunit 4; potassium large conductance calcium-activated channel, subfamily M, beta member 4; Slo-beta-4
Gene Symbols: KCNMB4
Molecular weight: 23,949 Da
Basal Isoelectric point: 6.29  Predict pI for various phosphorylation states
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Protein Structure Not Found.

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