| Identification |
|---|
| HMDB Protein ID
| HMDBP13658 |
| Secondary Accession Numbers
| None |
| Name
| Calcium-activated potassium channel subunit alpha-1 |
| Synonyms
|
- BK channel
- BKCA alpha
- Calcium-activated potassium channel, subfamily M subunit alpha-1
- K(VCA)alpha
- KCa1.1
- Maxi K channel
- Slo-alpha
- Slo1
- Slowpoke homolog
- MaxiK
- mSlo1
- Slo homolog
- mSlo
|
| Gene Name
| KCNMA1 |
| Protein Type
| Unknown |
| Biological Properties |
|---|
| General Function
| Not Available |
| Specific Function
| 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). |
| Pathways
|
- cGMP-PKG signaling pathway
- Insulin secretion
- Pancreatic secretion
- Renin secretion
- Salivary secretion
- Vascular smooth muscle contraction
|
| Reactions
| Not Available |
| GO Classification
|
| Biological Process |
| sensory perception of sound |
| neuromuscular process controlling balance |
| regulation of membrane potential |
| positive regulation of apoptotic process |
| locomotor rhythm |
| neuronal action potential |
| response to calcium ion |
| vasodilation |
| response to pH |
| cell maturation |
| adult walking behavior |
| relaxation of vascular smooth muscle |
| blood vessel diameter maintenance |
| cellular potassium ion homeostasis |
| eye blink reflex |
| inner ear auditory receptor cell differentiation |
| micturition |
| negative regulation of cell volume |
| negative regulation of small intestine smooth muscle contraction |
| regulation of aldosterone metabolic process |
| regulation of ion transmembrane transport |
| response to carbon monoxide |
| response to corticosteroid |
| saliva secretion |
| response to hypoxia |
| positive regulation of neuron apoptotic process |
| smooth muscle contraction involved in micturition |
| circadian rhythm |
| potassium ion transport |
| synaptic transmission |
| response to osmotic stress |
| response to estrogen stimulus |
| Cellular Component |
| protein-containing complex |
| cytoplasm |
| endoplasmic reticulum |
| plasma membrane |
| dendrite |
| perinuclear region of cytoplasm |
| postsynaptic membrane |
| terminal button |
| voltage-gated potassium channel complex |
| caveola |
| presynaptic active zone membrane |
| glutamatergic synapse |
| neuronal cell body |
| apical plasma membrane |
| external side of plasma membrane |
| integral component of presynaptic active zone membrane |
| integral to membrane |
| Molecular Function |
| actin binding |
| protein-containing complex binding |
| metal ion binding |
| calcium-activated potassium channel activity |
| voltage-gated potassium channel activity |
| large conductance calcium-activated potassium channel activity |
| ligand-gated ion channel activity involved in regulation of presynaptic membrane potential |
| potassium channel activity |
| identical protein binding |
|
| Cellular Location
|
Not Available
|
| Gene Properties |
|---|
| Chromosome Location
| Not Available |
| Locus
| Not Available |
| SNPs
| Not Available |
| Gene Sequence
|
Not Available
|
| Protein Properties |
|---|
| Number of Residues
| 1209 |
| Molecular Weight
| 134394.8 |
| Theoretical pI
| 7.151 |
| Pfam Domain Function
|
|
| Signals
|
Not Available
|
|
Transmembrane Regions
|
- 87-107;179-199;215-235;240-260;265-285;301-321;368-388;
|
| Protein Sequence
|
Not Available
|
| External Links |
|---|
| GenBank ID Protein
| Not Available |
| UniProtKB/Swiss-Prot ID
| Q08460 |
| UniProtKB/Swiss-Prot Entry Name
| KCMA1_MOUSE |
| PDB IDs
|
Not Available |
| GenBank Gene ID
| Not Available |
| GeneCard ID
| Not Available |
| GenAtlas ID
| Not Available |
| HGNC ID
| Not Available |
| References |
|---|
| General References
| - Pallanck L, Ganetzky B: Cloning and characterization of human and mouse homologs of the Drosophila calcium-activated potassium channel gene, slowpoke. Hum Mol Genet. 1994 Aug;3(8):1239-43. [PubMed:7987297 ]
- Weiger TM, Holmqvist MH, Levitan IB, Clark FT, Sprague S, Huang WJ, Ge P, Wang C, Lawson D, Jurman ME, Glucksmann MA, Silos-Santiago I, DiStefano PS, Curtis R: A novel nervous system beta subunit that downregulates human large conductance calcium-dependent potassium channels. J Neurosci. 2000 May 15;20(10):3563-70. [PubMed:10804197 ]
- Huttlin EL, Jedrychowski MP, Elias JE, Goswami T, Rad R, Beausoleil SA, Villen J, Haas W, Sowa ME, Gygi SP: A tissue-specific atlas of mouse protein phosphorylation and expression. Cell. 2010 Dec 23;143(7):1174-89. doi: 10.1016/j.cell.2010.12.001. [PubMed:21183079 ]
- Butler A, Tsunoda S, McCobb DP, Wei A, Salkoff L: mSlo, a complex mouse gene encoding "maxi" calcium-activated potassium channels. Science. 1993 Jul 9;261(5118):221-4. doi: 10.1126/science.7687074. [PubMed:7687074 ]
- Liu J, Asuncion-Chin M, Liu P, Dopico AM: CaM kinase II phosphorylation of slo Thr107 regulates activity and ethanol responses of BK channels. Nat Neurosci. 2006 Jan;9(1):41-9. doi: 10.1038/nn1602. Epub 2005 Dec 11. [PubMed:16341213 ]
- Shipston MJ, Duncan RR, Clark AG, Antoni FA, Tian L: Molecular components of large conductance calcium-activated potassium (BK) channels in mouse pituitary corticotropes. Mol Endocrinol. 1999 Oct;13(10):1728-37. doi: 10.1210/mend.13.10.0355. [PubMed:10517674 ]
- Cui J, Aldrich RW: Allosteric linkage between voltage and Ca(2+)-dependent activation of BK-type mslo1 K(+) channels. Biochemistry. 2000 Dec 19;39(50):15612-9. doi: 10.1021/bi001509+. [PubMed:11112549 ]
- Bao L, Rapin AM, Holmstrand EC, Cox DH: Elimination of the BK(Ca) channel's high-affinity Ca(2+) sensitivity. J Gen Physiol. 2002 Aug;120(2):173-89. doi: 10.1085/jgp.20028627. [PubMed:12149279 ]
- Shi J, Krishnamoorthy G, Yang Y, Hu L, Chaturvedi N, Harilal D, Qin J, Cui J: Mechanism of magnesium activation of calcium-activated potassium channels. Nature. 2002 Aug 22;418(6900):876-80. doi: 10.1038/nature00941. [PubMed:12192410 ]
- Xia XM, Zeng X, Lingle CJ: Multiple regulatory sites in large-conductance calcium-activated potassium channels. Nature. 2002 Aug 22;418(6900):880-4. doi: 10.1038/nature00956. [PubMed:12192411 ]
- Sokolowski S, Harvey M, Sakai Y, Jordan A, Sokolowski B: The large conductance calcium-activated K(+) channel interacts with the small GTPase Rab11b. Biochem Biophys Res Commun. 2012 Sep 21;426(2):221-5. doi: 10.1016/j.bbrc.2012.08.067. Epub 2012 Aug 21. [PubMed:22935415 ]
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