KCNMA1 Antibody – Rabbit Polyclonal

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, which is the product of this gene, and the modulatory beta subunit. Intracellular calcium regulates the physical association between the alpha and beta subunits. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

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). Defects in KCNMA1 are the cause of generalized epilepsy and paroxysmal dyskinesia (GEPD). Epilepsy is one of the most common and debilitating neurological disorders. Paroxysmal dyskinesias are neurological disorders characterized by sudden, unpredictable, disabling attacks of involuntary movement often requiring life-long treatment. The coexistence of epilepsy and paroxysmal dyskinesia in the same individual or family is an increasingly recognized phenomenon. Patients manifest absence seizures, generalized tonic-clonic seizures, paroxysmal nonkinesigenic dyskinesia, involuntary dystonic or choreiform movements. Onset is usually in childhood and patients may have seizures only, dyskinesia only, or both. Belongs to the potassium channel family. Calcium- activated (TC 1.A.1.3) subfamily. KCa1.1/KCNMA1 sub-subfamily. 7 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral; Endoplasmic reticulum; Channel, potassium; Membrane protein, multi-pass

Chromosomal Location of Human Ortholog: 10q22.3

Cellular Component: voltage-gated potassium channel complex; apical plasma membrane; plasma membrane; integral to membrane; caveola

Molecular Function: calcium-activated potassium channel activity; protein binding; voltage-gated potassium channel activity; metal ion binding; large conductance calcium-activated potassium channel activity; actin binding

Biological Process: synaptic transmission; regulation of membrane potential; smooth muscle contraction involved in micturition; positive regulation of apoptosis; response to hypoxia; response to calcium ion; blood coagulation; response to osmotic stress; negative regulation of cell volume; cellular potassium ion homeostasis; micturition; potassium ion transport

Disease: Generalized Epilepsy And Paroxysmal Dyskinesia