| 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 |
| regulation of membrane potential |
| sensory perception of sound |
| cellular potassium ion homeostasis |
| response to calcium ion |
| response to pH |
| response to estrogen stimulus |
| blood vessel diameter maintenance |
| vasodilation |
| adult walking behavior |
| smooth muscle contraction involved in micturition |
| response to osmotic stress |
| relaxation of vascular smooth muscle |
| positive regulation of neuron apoptotic process |
| potassium ion transport |
| locomotor rhythm |
| cell maturation |
| neuronal action potential |
| neuromuscular process controlling balance |
| saliva secretion |
| response to corticosteroid |
| response to carbon monoxide |
| regulation of ion transmembrane transport |
| regulation of aldosterone metabolic process |
| negative regulation of small intestine smooth muscle contraction |
| negative regulation of cell volume |
| micturition |
| inner ear auditory receptor cell differentiation |
| eye blink reflex |
| response to hypoxia |
| circadian rhythm |
| synaptic transmission |
| positive regulation of apoptotic process |
| Cellular Component |
| integral component of presynaptic active zone membrane |
| presynaptic active zone membrane |
| cytoplasm |
| voltage-gated potassium channel complex |
| external side of plasma membrane |
| integral to membrane |
| endoplasmic reticulum |
| plasma membrane |
| dendrite |
| perinuclear region of cytoplasm |
| postsynaptic membrane |
| neuronal cell body |
| apical plasma membrane |
| glutamatergic synapse |
| caveola |
| terminal button |
| protein-containing complex |
| Molecular Function |
| actin binding |
| potassium channel activity |
| ligand-gated ion channel activity involved in regulation of presynaptic membrane potential |
| large conductance calcium-activated potassium channel activity |
| calcium-activated potassium channel activity |
| identical protein binding |
| metal ion binding |
| protein-containing complex binding |
| voltage-gated potassium channel activity |
|
| 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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