KCMA1_CHICK
ID KCMA1_CHICK Reviewed; 1137 AA.
AC Q8AYS8; O12942; O13110; O93569; Q98951; Q9PS76;
DT 13-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT 13-APR-2004, sequence version 2.
DT 03-AUG-2022, entry version 150.
DE RecName: Full=Calcium-activated potassium channel subunit alpha-1;
DE AltName: Full=BK channel;
DE AltName: Full=BKCA alpha;
DE AltName: Full=Calcium-activated potassium channel, subfamily M subunit alpha-1;
DE AltName: Full=K(VCA)alpha;
DE AltName: Full=KCa1.1;
DE AltName: Full=Maxi K channel;
DE Short=MaxiK;
DE AltName: Full=Slo-alpha;
DE AltName: Full=Slo1;
DE AltName: Full=Slowpoke homolog;
DE Short=Slo homolog;
DE Short=cSlo;
GN Name=KCNMA1; Synonyms=KCNMA;
OS Gallus gallus (Chicken).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda;
OC Coelurosauria; Aves; Neognathae; Galloanserae; Galliformes; Phasianidae;
OC Phasianinae; Gallus.
OX NCBI_TaxID=9031;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), AND NUCLEOTIDE SEQUENCE OF 398-1137
RP (ISOFORM 4).
RC STRAIN=Leghorn; TISSUE=Cochlear duct;
RX PubMed=9178544; DOI=10.1098/rspb.1997.0104;
RA Jiang G.J., Zidanic M., Michaels R.L., Michael T.H., Griguer C.,
RA Fuchs P.A.;
RT "CSlo encodes calcium-activated potassium channels in the chick's
RT cochlea.";
RL Proc. R. Soc. B 264:731-737(1997).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS 1; 2; 3; 4; 5; 6; 7; 8; 9 AND 10).
RC STRAIN=White leghorn; TISSUE=Brain;
RX PubMed=9390519; DOI=10.1016/s0896-6273(00)80397-9;
RA Rosenblatt K.P., Sun Z.-P., Heller S., Hudspeth A.J.;
RT "Distribution of Ca2+-activated K+ channel isoforms along the tonotopic
RT gradient of the chicken's cochlea.";
RL Neuron 19:1061-1075(1997).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RC STRAIN=White leghorn; TISSUE=Lens epithelium;
RX PubMed=9543635; DOI=10.1076/ceyr.17.3.264.5224;
RA Rae J.L., Shepard A.R.;
RT "Molecular biology and electrophysiology of calcium-activated potassium
RT channels from lens epithelium.";
RL Curr. Eye Res. 17:264-275(1998).
RN [4]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 24-1137 (ISOFORM 3).
RX PubMed=10362660; DOI=10.1152/ajpheart.1999.276.6.h1827;
RA Kawakubo T., Naruse K., Matsubara T., Hotta N., Sokabe M.;
RT "Characterization of a newly found stretch-activated KCa,ATP channel in
RT cultured chick ventricular myocytes.";
RL Am. J. Physiol. 276:H1827-H1838(1999).
RN [5]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 710-973 (ISOFORM 5).
RX PubMed=8755483; DOI=10.1016/s0896-6273(00)80285-8;
RA Subramony P., Raucher S., Dryer L., Dryer S.E.;
RT "Posttranslational regulation of Ca(2+)-activated K+ currents by a target-
RT derived factor in developing parasympathetic neurons.";
RL Neuron 17:115-124(1996).
RN [6]
RP FUNCTION.
RX PubMed=9880252; DOI=10.1126/science.283.5399.215;
RA Ramanathan K., Michael T.H., Jiang G.-J., Hiel H., Fuchs P.A.;
RT "A molecular mechanism for electrical tuning of cochlear hair cells.";
RL Science 283:215-217(1999).
CC -!- FUNCTION: Potassium channel activated by both membrane depolarization
CC or increase in cytosolic Ca(2+) that mediates export of K(+). It is
CC also activated by the concentration of cytosolic Mg(2+). Its activation
CC dampens the excitatory events that elevate the cytosolic Ca(2+)
CC concentration and/or depolarize the cell membrane. It therefore
CC contributes to repolarization of the membrane potential. Plays a key
CC role in controlling excitability in a number of systems, such as
CC regulation of the contraction of smooth muscle, the tuning of hair
CC cells in the cochlea, regulation of transmitter release, and innate
CC immunity. In smooth muscles, its activation by high level of Ca(2+),
CC caused by ryanodine receptors in the sarcoplasmic reticulum, regulates
CC the membrane potential. In cochlea cells, its number and kinetic
CC properties partly determine the characteristic frequency of each hair
CC cell and thereby helps to establish a tonotopic map. Highly sensitive
CC to both iberiotoxin (IbTx) and charybdotoxin (CTX).
CC {ECO:0000269|PubMed:9880252}.
CC -!- ACTIVITY REGULATION: Ethanol and carbon monoxide-bound heme increase
CC channel activation. Heme inhibits channel activation (By similarity).
CC {ECO:0000250}.
CC -!- SUBUNIT: Homotetramer; which constitutes the calcium-activated
CC potassium channel. {ECO:0000250}.
CC -!- INTERACTION:
CC Q8AYS8; O57513: akt1; NbExp=2; IntAct=EBI-1635766, EBI-4306384;
CC Q8AYS8; P17153: ANXA5; NbExp=3; IntAct=EBI-1635766, EBI-1635947;
CC Q8AYS8; P08251: ATP1B1; NbExp=3; IntAct=EBI-1635766, EBI-7206371;
CC Q8AYS8; Q01406: CTTN1; NbExp=2; IntAct=EBI-1635766, EBI-2530463;
CC Q8AYS8; F1NPL8: GSK3A; NbExp=2; IntAct=EBI-1635766, EBI-4306413;
CC Q8AYS8; P42324: HPCAL1; NbExp=3; IntAct=EBI-1635766, EBI-1636399;
CC Q8AYS8; Q90593: HSPA5; NbExp=3; IntAct=EBI-1635766, EBI-1635886;
CC Q8AYS8; Q5ZL72: HSPD1; NbExp=3; IntAct=EBI-1635766, EBI-1635874;
CC Q8AYS8; Q5F425: LIN7C; NbExp=3; IntAct=EBI-1635766, EBI-1636456;
CC Q8AYS8; F1NLP2: PDK1; NbExp=2; IntAct=EBI-1635766, EBI-4306427;
CC Q8AYS8; P84173: PHB; NbExp=3; IntAct=EBI-1635766, EBI-1636878;
CC Q8AYS8; F1NSA8: RAP1A; NbExp=2; IntAct=EBI-1635766, EBI-4306330;
CC Q8AYS8; P60878: SNAP25; NbExp=3; IntAct=EBI-1635766, EBI-1637031;
CC Q8AYS8; P80566: SOD1; NbExp=3; IntAct=EBI-1635766, EBI-1637015;
CC Q8AYS8; P31395: STMN1; NbExp=3; IntAct=EBI-1635766, EBI-1636998;
CC Q8AYS8; Q5ZMU9: VCP; NbExp=3; IntAct=EBI-1635766, EBI-1637127;
CC Q8AYS8; Q5F3W6: YWHAG; NbExp=3; IntAct=EBI-1635766, EBI-1635853;
CC Q8AYS8; P08106; NbExp=3; IntAct=EBI-1635766, EBI-1636307;
CC -!- SUBCELLULAR LOCATION: Membrane {ECO:0000250}; Multi-pass membrane
CC protein {ECO:0000250}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=10;
CC Comment=Additional isoforms seem to exist.;
CC Name=1;
CC IsoId=Q8AYS8-1; Sequence=Displayed;
CC Name=2;
CC IsoId=Q8AYS8-2; Sequence=VSP_009985;
CC Name=3;
CC IsoId=Q8AYS8-3; Sequence=VSP_009987;
CC Name=4;
CC IsoId=Q8AYS8-4; Sequence=VSP_009991;
CC Name=5; Synonyms=IK;
CC IsoId=Q8AYS8-5; Sequence=VSP_009990;
CC Name=6;
CC IsoId=Q8AYS8-6; Sequence=VSP_009988;
CC Name=7;
CC IsoId=Q8AYS8-7; Sequence=VSP_009983;
CC Name=8;
CC IsoId=Q8AYS8-8; Sequence=VSP_009984;
CC Name=9;
CC IsoId=Q8AYS8-9; Sequence=VSP_009986;
CC Name=10;
CC IsoId=Q8AYS8-10; Sequence=VSP_009989;
CC -!- DOMAIN: The S0 segment is essential for the modulation by the accessory
CC beta subunits. {ECO:0000250}.
CC -!- DOMAIN: The S4 segment, which is characterized by a series of
CC positively charged amino acids at every third position, is part of the
CC voltage-sensor. {ECO:0000250}.
CC -!- DOMAIN: The pore-forming domain (also referred as P region) is imbedded
CC into the membrane, and forms the selectivity filter of the pore. It
CC contains the signature sequence of potassium channels that displays
CC selectivity to potassium (By similarity). {ECO:0000250}.
CC -!- DOMAIN: The RCK N-terminal domain mediates the homotetramerization,
CC thereby promoting the assembly of monomers into functional potassium
CC channel. It includes binding sites for Ca(2+) and Mg(2+) (By
CC similarity). {ECO:0000250}.
CC -!- DOMAIN: The calcium bowl constitutes one of the Ca(2+) sensors and
CC probably acts as a Ca(2+)-binding site. There are however other Ca(2+)
CC sensors regions required for activation of the channel (By similarity).
CC {ECO:0000250}.
CC -!- DOMAIN: The heme-binding motif mediates inhibition of channel
CC activation by heme. Carbon monoxide-bound heme leads to increased
CC channel activation (By similarity). {ECO:0000250}.
CC -!- MISCELLANEOUS: The protein was initially thought to contain two
CC functionally distinct parts: The core channel (from the N-terminus to
CC the S9 segment) that mediates the channel activity, and the cytoplasmic
CC tail (from the S9 segment to the C-terminus) that mediates the calcium
CC sensing. The situation is however more complex, since the core channel
CC contains binding sites for Ca(2+) and Mg(2+).
CC -!- SIMILARITY: Belongs to the potassium channel family. Calcium-activated
CC (TC 1.A.1.3) subfamily. KCa1.1/KCNMA1 sub-subfamily. {ECO:0000305}.
CC -!- CAUTION: It is uncertain whether Met-1 is the initiator or if the
CC sequence starts further upstream. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; U23821; AAC60378.1; -; mRNA.
DR EMBL; U23823; AAC60125.1; -; mRNA.
DR EMBL; U73189; AAB17873.1; -; mRNA.
DR EMBL; AF087663; AAC35370.1; -; mRNA.
DR EMBL; AB072618; BAC20639.1; -; mRNA.
DR RefSeq; NP_989555.1; NM_204224.1.
DR AlphaFoldDB; Q8AYS8; -.
DR SMR; Q8AYS8; -.
DR BioGRID; 675104; 111.
DR IntAct; Q8AYS8; 106.
DR MINT; Q8AYS8; -.
DR STRING; 9031.ENSGALP00000039705; -.
DR iPTMnet; Q8AYS8; -.
DR PaxDb; Q8AYS8; -.
DR PRIDE; Q8AYS8; -.
DR Ensembl; ENSGALT00000007982; ENSGALP00000007968; ENSGALG00000004980. [Q8AYS8-8]
DR Ensembl; ENSGALT00000040502; ENSGALP00000039705; ENSGALG00000004980. [Q8AYS8-1]
DR GeneID; 374065; -.
DR KEGG; gga:374065; -.
DR CTD; 3778; -.
DR VEuPathDB; HostDB:geneid_374065; -.
DR eggNOG; KOG1420; Eukaryota.
DR GeneTree; ENSGT00940000154935; -.
DR InParanoid; Q8AYS8; -.
DR OrthoDB; 124461at2759; -.
DR Reactome; R-GGA-1296052; Ca2+ activated K+ channels.
DR PRO; PR:Q8AYS8; -.
DR Proteomes; UP000000539; Chromosome 6.
DR Bgee; ENSGALG00000004980; Expressed in colon and 9 other tissues.
DR ExpressionAtlas; Q8AYS8; baseline and differential.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0045211; C:postsynaptic membrane; IBA:GO_Central.
DR GO; GO:0060072; F:large conductance calcium-activated potassium channel activity; IBA:GO_Central.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0005244; F:voltage-gated ion channel activity; IEA:UniProtKB-KW.
DR GO; GO:0034765; P:regulation of ion transmembrane transport; IEA:UniProtKB-KW.
DR InterPro; IPR024939; Ca-act_K_channel_Slo-1.
DR InterPro; IPR005821; Ion_trans_dom.
DR InterPro; IPR003929; K_chnl_BK_asu.
DR InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR PANTHER; PTHR10027:SF28; PTHR10027:SF28; 2.
DR Pfam; PF03493; BK_channel_a; 1.
DR Pfam; PF00520; Ion_trans; 1.
DR SUPFAM; SSF51735; SSF51735; 1.
PE 1: Evidence at protein level;
KW Alternative splicing; Calcium; Ion channel; Ion transport; Magnesium;
KW Membrane; Metal-binding; Potassium; Potassium channel; Potassium transport;
KW Reference proteome; Transmembrane; Transmembrane helix; Transport;
KW Voltage-gated channel.
FT CHAIN 1..1137
FT /note="Calcium-activated potassium channel subunit alpha-1"
FT /id="PRO_0000054138"
FT TOPO_DOM 1..44
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 45..65
FT /note="Helical; Name=Segment S0"
FT /evidence="ECO:0000255"
FT TOPO_DOM 66..137
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT TRANSMEM 138..158
FT /note="Helical; Name=Segment S1"
FT /evidence="ECO:0000255"
FT TOPO_DOM 159..173
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 174..194
FT /note="Helical; Name=Segment S2"
FT /evidence="ECO:0000255"
FT TOPO_DOM 195..198
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT TRANSMEM 199..219
FT /note="Helical; Name=Segment S3"
FT /evidence="ECO:0000255"
FT TOPO_DOM 220..223
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 224..244
FT /note="Helical; Voltage-sensor; Name=Segment S4"
FT /evidence="ECO:0000255"
FT TOPO_DOM 245..259
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT TRANSMEM 260..280
FT /note="Helical; Name=Segment S5"
FT /evidence="ECO:0000255"
FT TOPO_DOM 281..294
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT INTRAMEM 295..317
FT /note="Pore-forming; Name=P region"
FT /evidence="ECO:0000255"
FT TOPO_DOM 318..326
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 327..347
FT /note="Helical; Name=Segment S6"
FT /evidence="ECO:0000255"
FT TOPO_DOM 348..1137
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT DOMAIN 374..517
FT /note="RCK N-terminal"
FT REGION 515..535
FT /note="Segment S7"
FT REGION 572..592
FT /note="Segment S8"
FT REGION 636..640
FT /note="Heme-binding motif"
FT REGION 660..688
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 738..758
FT /note="Segment S9"
FT REGION 933..953
FT /note="Segment S10"
FT REGION 1088..1137
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 311..314
FT /note="Selectivity for potassium"
FT MOTIF 904..926
FT /note="Calcium bowl"
FT COMPBIAS 667..685
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 1088..1118
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 1119..1137
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 398
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250"
FT BINDING 421
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250"
FT BINDING 423
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250"
FT BINDING 913
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 916
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 919
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT BINDING 921
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /evidence="ECO:0000250"
FT VAR_SEQ 1..17
FT /note="MSNNINANNLNTDSSSS -> MKPFEVSLPPPPPS (in isoform 7)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009983"
FT VAR_SEQ 160
FT /note="N -> KSRTADSLI (in isoform 8)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009984"
FT VAR_SEQ 602
FT /note="S -> RSRKR (in isoform 2)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009985"
FT VAR_SEQ 602
FT /note="S -> RSRKRYALFVTFPSNLNPTST (in isoform 9)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009986"
FT VAR_SEQ 657
FT /note="L -> PKMSIYKRMKLACCFDCGRSERDCSCMSGSVHSNMDTLERAFPLSSV
FT SVNDCSTSLRAF (in isoform 3)"
FT /evidence="ECO:0000303|PubMed:10362660,
FT ECO:0000303|PubMed:9390519"
FT /id="VSP_009987"
FT VAR_SEQ 657
FT /note="L -> IYF (in isoform 6)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009988"
FT VAR_SEQ 687
FT /note="M -> MRFSCPFLP (in isoform 10)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009989"
FT VAR_SEQ 906
FT /note="L -> LAKPGKLLPLVSISQEKNSGTQILMITEL (in isoform 5)"
FT /evidence="ECO:0000303|PubMed:8755483,
FT ECO:0000303|PubMed:9390519"
FT /id="VSP_009990"
FT VAR_SEQ 1130..1137
FT /note="KYVQEDRL -> NSTRMNRMGQEKKWFTDEPDNAYPRNIQIKPMSTHMANQI
FT NQYKSTSSLIPPIREVEDEC (in isoform 4)"
FT /evidence="ECO:0000303|PubMed:9390519"
FT /id="VSP_009991"
FT CONFLICT 96
FT /note="Q -> R (in Ref. 1; AAC60378)"
FT /evidence="ECO:0000305"
FT CONFLICT 397
FT /note="V -> I (in Ref. 1; AAC60378)"
FT /evidence="ECO:0000305"
FT CONFLICT 409
FT /note="L -> P (in Ref. 4; AAC35370)"
FT /evidence="ECO:0000305"
FT CONFLICT 522
FT /note="C -> S (in Ref. 1; AAC60378)"
FT /evidence="ECO:0000305"
FT CONFLICT 712
FT /note="S -> W (in Ref. 5; BAC20639)"
FT /evidence="ECO:0000305"
FT CONFLICT 937
FT /note="T -> P (in Ref. 5; BAC20639)"
FT /evidence="ECO:0000305"
FT CONFLICT 941
FT /note="V -> D (in Ref. 5; BAC20639)"
FT /evidence="ECO:0000305"
FT CONFLICT 1034
FT /note="L -> F (in Ref. 4; AAC35370)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 1137 AA; 127647 MW; 40A9735E586F0BD1 CRC64;
MSNNINANNL NTDSSSSPVN VPKMDALIIP VTMEVPCDSR GQRMWWAFLA SSMVTFFGGL
FIILLWRTLK YLWTVCCHCG VKNKEAQKIN GGGDTQADGA CKPTDEKEEN VAAEVGWMTS
VKDWAGVMIS AQTLTGRVLV VLVFALSIGA LVIYFIDSSN PIESCQNFYK DFTLQIDMAF
NVFFLLYFGL RFIAANDKLW FWLEVNSVVD FFTVPPVFVS VYLNRSWLGL RFLRALRLIQ
FSEILQFLNI LKTSNSIKLV NLCSIFISTW LTAAGFIHLV ENSGDPWENF QNNQQLTYWE
CVYLLMVTMS TVGYGDVYAK TTLGRLFMVF FILGGLAMFA SYVPEIIELI GNRKKYGGSY
SAVSGRKHIV VCGHITLESV SNFLKDFLHK DRDDVNVEIV FLHNISPNLE LEALFKRHFT
QVEFYQGSVL NPHDLARVKI ESADACLILA NKYCADPDAE DASNIMRVIS IKNYHPKIRI
ITQMLQYHNK AHLLNIPSWN WKEGDDAICL AELKLGFIAQ SCLAPGLSTM LANLFSMRSF
IKIEEDTWQK YYLEGVANEM YTEYLSSAFV GLSFPAVCEL VFAKLKLLMI AIEYKSEKRE
SSILINPGNH VKIQEGTLGF FIASDAKEVK RAFFYCKACH DDITDPKRIK KCGCKRLEDE
QPSTLSPKKK QRNGGMRNSP NSSPKLMRHD PLLIPGNEQI DNMDANVKKY DSTGMFHWCP
AKDIEKVILT RSEAAMTVLS GHVVVCIFGD VKSALIGLRN LVMPLRASNF HYHELKHIVF
VGSLEYLRRE WETLHNFPKV SILPGTPLSR ADLRAVNINL CDMCVILSAN QNNIDDASLQ
DKECILASLN IKSMQFDDSI GVLQANSQGF TPPGMDRSSP DNSPVHGLLR QPSITTGANI
PIITELVNDS NVQFLDQDDD DDPDTELYLT QPFACGTAFA VSVLDSLMSA TYFNDNILTL
IRTLVTGGAT PELEALIAEE NALRGGYSTP QTLANRDRCR VAQLALYDGP FADLGDGGCY
GDLFCKALKT YNMLCFGIYR LRDAHLSTPS QCTKRYVITN PPYEFELVPT DLIFCLMQFD
HNAGQSRASL SHSSHSSYSS SKKSSSVHSI PSTANRPNRT KTRDSREKQK YVQEDRL
