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Symbol KCNMA1 contributors: mct/npt - updated : 23-06-2014
HGNC name potassium large conductance calcium-activated channel, subfamily M, alpha member 1
HGNC id 6284
Corresponding disease
GEPD generalized epilepsy and paroxysmal dyskinesia
Location 10q22.3      Physical location : 78.629.358 - 79.397.577
Synonym name
  • maxi K channel alpha 1 subunit
  • large conductance calcium-activated potassium channel subfamily M alpha member 1
  • stretch-activated Kca channel
  • BKCA alpha subunit
  • Drosophila slowpoke-like
  • Slo homolog
  • Synonym symbol(s) KCNS, SLO, MaxiK, KCa1.1, SLO-ALPHA, BKTM, SLO1, mSLO1, SAKCA, DKFZp686K1437, MGC71881, BK
    TYPE functioning gene
    STRUCTURE 768.22 kb     29 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    text structure no TATA box
    MAPPING cloned Y linked N status confirmed
    Map cen - D10S195 - D10S580 -D10S1730 - KCNMA1 - D10S605 - D10S1752 - D10S206 - SFTPD - ANXA11 - D10S1786 - qter
    Physical map
    MRPL35P3 10q22.2 potassium large conductance calcium-activated channel, subfamily M, alpha member 1 LOC389979 10 similar to hypothetical protein DKFZp586O0120.1 - human (fragment) MYST4 10q22.2 MYST histone acetyltransferase (monocytic leukemia) 4 DUPD1 10q22.3 dual specificity phosphatase and pro isomerase domain containing 1 DUSP13 10q22.3 dual specificity phosphatase 13 SAMD8 10q22.3 sterile alpha motif domain containing 8 VDAC2 10q22 voltage-dependent anion channel 2 FLJ23841 10q22.3 hypothetical protein FLJ23841 LOC387687 10 LOC387687 SPA17P1 10q22.3 sperm autoantigenic protein 17 pseudogene 1 ZNF503 10q22.3 zinc finger protein 503 LOC283065 10q22.3 hypothetical gene supported by BC017426 LOC387688 10 LOC387688 CDA017 KCNMA1 10q22.3 potassium large conductance calcium-activated channel, subfamily M, alpha member 1 LOC283046 10q22.3 similar to zinc finger protein LOC340780 10q22.3 similar to Inosine-5-monophosphate dehydrogenase 1 (IMP dehydrogenase 1) (IMPDH-I) (IMPD 1) DLG5 10q22.3 discs, large (Drosophila) homolog 5 LOC387689 10 LOC387689 RPC155 10q22.3 LOC387689 RPS24 10q22.3 ribosomal protein S24 LOC389980 10 similar to Guanine nucleotide-binding protein G(i), alpha-2 subunit (Adenylate cyclase-inhibiting G alpha protein) LOC387690 10 LOC387690 LOC387691 10 LOC387691
    TRANSCRIPTS type messenger
    text multiple transcripts by alternative splicing (PMID: 7987297)
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    27 - 6120 - 1178 - 2008 18227273
    28 splicing 6294 - 1236 overexpressed in glioma cells -
    63 AA insert at splice site 2
    28 splicing 6243 - 1219 - -
    29 AA insert at splice site 2; having the greatest calcium sensitivity
    29 - 11994 - 1182 - 2008 18227273
    Type widely
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Reproductivefemale systemuterus  highly
    Respiratorynasopharynx   highly
     respiratory tractlarynx  highly
    cell lineage
    cell lines
    at STAGE
    IMPRINTING maternally
    text down-regulated expression in androgenetic placentas
  • N-terminal seven transmembrane domains (S0 to S6)
  • two functional domains, a core consisting of four voltage sensors controlling an ion-conducting pore, and a larger tail that forms an intracellular gating ring thought to confer Ca(2+) and Mg(2+) sensitivity
  • a RCK1 domain between S6 and S8, that is a high-affinity Ca(2+) sensor that transduces Ca(2+) binding into structural rearrangements, likely representing elementary steps in the Ca(2+)-dependent activation of KCNMA1 channels
  • a calcium bowl
  • CRAC motifs, cholesterol-binding motifs
  • an extensive C-terminus with four hydrophobic segments (S7 to S10), and a motif required for surface targeting
  • mono polymer homomer , tetramer
    interspecies homolog to Drosophila slowpoke
  • potassium channel family
  • calcium-activated subfamily
  • CATEGORY transport channel
        plasma membrane
    intracellular,cytoplasm,organelle,endoplasmic reticulum
    basic FUNCTION
  • control of smooth muscle tone and neuronal excitability
  • constituting the calcium-activated potassium channel and playing 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
  • play a fundamental role in cellular function by integrating information from their voltage and Ca(2+) sensors to control membrane potential and Ca(2+) homeostasis
  • role of endothelial KCNM1A channels in altered vasoreactivity following hypoxia
  • mediate cholinergic inhibition of high frequency cochlear hair cells
  • play important roles in regulating vascular contractility
  • (egulate neuronal functions such as spike frequency adaptation and transmitter release
  • modulate visual responses in vivo at the bipolar cell level at intermediate stimulus conditions
    signaling neurotransmission , signal transduction
    a component
  • pore constituent (forming alpha member 1) complexing with alternative beta subunits
  • composed of four KCNMA1 subunits, which contain the voltage-sensing and pore-gate domains in the membrane and Ca(2+) binding sites in the cytoplasmic domain, and accessory beta subunits
    small molecule
  • interacting with beta subunits KCNMB1, KCNMB2, KCNMB3 and KCNMB4
  • interaction with caveolin-1 (interaction facilitating the tethering of the KCNMA1 C-terminal end to the membrane)
  • binds MAGI1
  • WNK4 inhibits KCNMA1 activity by reducing KCNMA1 protein at the membrane, but the inhibition is not due to an increase in clathrin-mediated endocytosis of KCNMA1, but likely due to enhancing its lysosomal degradation
  • insulin stimulation of KCNMA1 channels in podocytes may prepare podocytes to adapt to changes in pressure gradients that occur during postprandial hyperfiltration
  • RAB11B has a moderate association with a region of KCNMA1 that includes AA 127616, and this interaction of RAB11B and KCNMA1 is in cochlea
  • lack of TMPRSS3 leads to a decrease in KCNMA1 potassium channels expression in inner hair cells (IHCs)
  • CRBN inactivation releases deubiquitinated KCNMA1 channels from the ER to the plasma membrane, leading to markedly enhanced channel activity
  • LRRC26 associates with KCNMA1 subunits, and elevates channel voltage- and apparent Ca2+-sensitivity in arterial myocytes to induce vasodilation (PMID;
  • cell & other
    activated by intracellular Zn(2+) that potently and reversibly activates large-conductance voltage- and Ca(2+)-activated KCNMA1
    corresponding disease(s) GEPD
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    tumoral   amplification    
    in late-stage prostate cancer
    Variant & Polymorphism
    Candidate gene
    Therapy target promising diagnostic and therapeutic target in patients with prostate cancer