KCNMA1 - Calcium-activated potassium channel subunit alpha-1 - human protein (Function)
 
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KCNMA1 »  Calcium-activated potassium channel subunit alpha-1
 
Protein also known as:  Calcium-activated potassium channel, subfamily M subunit alpha-1.
Gene name:  KCNMA1
Entry whose protein(s) existence is based on evidence at protein level
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GENE REF ISO

Function

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Overview 
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).  
1
  • UniProtKB
GO molecular function 
Actin bindingdefinition[GO:0003779]  
1
  • BHF-UCL
Calcium-activated potassium channel activitydefinition[GO:0015269]  
7
  • UniProtKB
Large conductance calcium-activated potassium channel activitydefinition[GO:0060072]  
2
  • BHF-UCL
  • UniProtKB
Metal ion bindingdefinition[GO:0046872]  
1
  • UniProtKB KW
Protein bindingdefinition[GO:0005515]  
4
  • UniProtKB
  • BHF-UCL
Voltage-gated potassium channel activitydefinition[GO:0005249]  
4
  • UniProtKB
GO biological process 
Cellular potassium ion homeostasisdefinition[GO:0030007]  
1
  • UniProtKB
Micturitiondefinition[GO:0060073]  
1
  • UniProtKB
Negative regulation of cell volumedefinition[GO:0045794]  
1
  • UniProtKB
Positive regulation of apoptotic processdefinition[GO:0043065]  
1
  • UniProtKB
Potassium ion transmembrane transportdefinition[GO:0071805]  
3
  • GOC
  • RefGenome
Potassium ion transportdefinition[GO:0006813]  
7
  • UniProtKB
Regulation of ion transmembrane transportdefinition[GO:0034765]  
1
  • UniProtKB KW
Regulation of membrane potentialdefinition[GO:0042391]  
2
  • UniProtKB
Response to calcium iondefinition[GO:0051592]  
2
  • UniProtKB
Response to carbon monoxidedefinition[GO:0034465]  
2
  • UniProtKB
Response to hypoxiadefinition[GO:0001666]  
1
  • UniProtKB
Response to osmotic stressdefinition[GO:0006970]  
2
  • UniProtKB
Smooth muscle contraction involved in micturitiondefinition[GO:0060083]  
1
  • UniProtKB
Enzymatic activity 
It is regulated in the following manner
Ethanol and carbon monoxide-bound heme increase channel activation. Heme inhibits channel activation.  
2
  • UniProtKB
Pathways 
According to KEGG, this protein belongs to the following pathways:
Pancreatic secretion  hsa04972+3778  
Salivary secretion  hsa04970+3778  
Vascular smooth muscle contraction  hsa04270+3778  
According to Reactome, this protein belongs to the following pathways:
Ca2+ activated K+ channels  REACT_75896  
cGMP effects  REACT_23767  
 

Keywords

Biological process 
Ion transport  definition   [KW-0406]
Potassium transport  definition   [KW-0633]
Transport  definition   [KW-0813]
Molecular function 
Ion channel  definition   [KW-0407]
Potassium channel  definition   [KW-0631]
Voltage-gated channel  definition   [KW-0851]
Technical term 
Reference proteome  definition   [KW-1185]
 

Further external links

Other
GenomeRNAi: 3778
PRO: PR:Q12791
Chemistry
GuidetoPHARMACOLOGY: 380