KCNMA1
Potassium channel activated by both membrane depolarization or increase in cytosolic Ca(2+) that mediates export of K(+). It is also activated by the concentration of cytosolic Mg(2+). Its activation dampens the excitatory events that elevate the cytosolic Ca(2+) concentration and/or depolarize the cell membrane. It therefore contributes to repolarization of the membrane potential. Plays a key role in controlling excitability in a number of systems, such as regulation of the contraction of smooth muscle, the tuning of hair cells in the cochlea, regulation of transmitter release, and innate immunity. In smooth muscles, its activation by high level of Ca(2+), caused by ryanodine receptors in the sarcoplasmic reticulum, regulates the membrane potential. In cochlea cells, its number and kinetic properties partly determine the characteristic frequency of each hair cell and thereby helps to establish a tonotopic map. Kinetics of KCNMA1 channels are determined by alternative splicing, phosphorylation status and its combination with modulating beta subunits. Highly sensitive to both iberiotoxin (IbTx) and charybdotoxin (CTX). Belongs to the potassium channel family. Calcium-activated (TC 1.A.1.3) subfamily. KCa1.1/KCNMA1 sub-subfamily. Widely expressed. Except in myocytes, it is almost ubiquitously expressed. 7 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
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Protein type: Channel, potassium; Endoplasmic reticulum; Membrane protein, integral; Membrane protein, multi-pass |
Chromosomal Location of mouse Ortholog: 14|14 A3 |
Cellular Component:
apical plasma membrane; caveola; dendrite; endoplasmic reticulum; external side of plasma membrane; glutamatergic synapse; membrane; neuronal cell body; perinuclear region of cytoplasm; plasma membrane; postsynaptic membrane; presynaptic active zone membrane; protein-containing complex; sarcoplasm; terminal bouton; voltage-gated potassium channel complex
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Molecular Function:
actin binding; calcium-activated potassium channel activity; identical protein binding; large conductance calcium-activated potassium channel activity; ligand-gated monoatomic ion channel activity involved in regulation of presynaptic membrane potential; metal ion binding; monoatomic ion channel activity; potassium channel activity; protein binding; protein-containing complex binding; voltage-gated monoatomic ion channel activity; voltage-gated potassium channel activity
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Biological Process:
adult walking behavior; blood vessel diameter maintenance; chemical synaptic transmission; circadian rhythm; columnar/cuboidal epithelial cell maturation; eye blink reflex; inner ear auditory receptor cell differentiation; intracellular potassium ion homeostasis; locomotor rhythm; micturition; monoatomic ion transport; negative regulation of cell volume; negative regulation of small intestine smooth muscle contraction; neuromuscular process controlling balance; neuron maturation; neuronal action potential; positive regulation of apoptotic process; positive regulation of neuron apoptotic process; potassium ion transmembrane transport; potassium ion transport; regulation of aldosterone metabolic process; regulation of membrane potential; regulation of monoatomic ion transmembrane transport; relaxation of vascular associated smooth muscle; response to calcium ion; response to carbon monoxide; response to estrogen; response to hypoxia; response to osmotic stress; response to pH; saliva secretion; sensory perception of sound; smooth muscle contraction involved in micturition; transmembrane transport; vasodilation
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Reference #:
Q08460
(UniProtKB)
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Alt. Names/Synonyms: 5730414M22Rik; BK channel; BK channel alpha subunit; BKC; BKCa; BKCA alpha; Calcium-activated potassium channel subunit alpha-1; Calcium-activated potassium channel, subfamily M subunit alpha-1; K(VCA)alpha; KCa1.1; KCMA1; Kcnma; Kcnma1; Max; Maxi K channel; MaxiK; mSlo; mSlo1; potassium large conductance calcium-activated channel, subfamily M, alpha member 1; Slo; Slo homolog; Slo-alpha; Slo1; Slowpoke homolog
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Gene Symbols: Kcnma1
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Molecular weight:
134,396 Da
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Basal Isoelectric point:
6.75
Predict pI for various phosphorylation states
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