ID A0A2Y9IJZ3_ENHLU Unreviewed; 191 AA.
AC A0A2Y9IJZ3;
DT 12-SEP-2018, integrated into UniProtKB/TrEMBL.
DT 12-SEP-2018, sequence version 1.
DT 27-MAR-2024, entry version 20.
DE RecName: Full=Calcium-activated potassium channel subunit beta {ECO:0000256|RuleBase:RU368097};
DE Short=BKbeta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=BK channel subunit beta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=Calcium-activated potassium channel, subfamily M subunit beta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=Charybdotoxin receptor subunit beta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=K(VCA)beta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=Maxi K channel subunit beta {ECO:0000256|RuleBase:RU368097};
DE AltName: Full=Slo-beta {ECO:0000256|RuleBase:RU368097};
GN Name=LOC111140972 {ECO:0000313|RefSeq:XP_022348967.1};
OS Enhydra lutris kenyoni (northern sea otter).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Carnivora; Caniformia; Musteloidea; Mustelidae;
OC Lutrinae; Enhydra.
OX NCBI_TaxID=391180 {ECO:0000313|Proteomes:UP000248482, ECO:0000313|RefSeq:XP_022348967.1};
RN [1] {ECO:0000313|RefSeq:XP_022348967.1}
RP IDENTIFICATION.
RC TISSUE=Blood {ECO:0000313|RefSeq:XP_022348967.1};
RG RefSeq;
RL Submitted (NOV-2023) to UniProtKB.
CC -!- FUNCTION: Regulatory subunit of the calcium activated potassium KCNMA1
CC (maxiK) channel. Modulates the calcium sensitivity and gating kinetics
CC of KCNMA1, thereby contributing to KCNMA1 channel diversity. Increases
CC the apparent Ca(2+)/voltage sensitivity of the KCNMA1 channel. It also
CC modifies KCNMA1 channel kinetics and alters its pharmacological
CC properties. It slows down the activation and the deactivation kinetics
CC of the channel. Acts as a negative regulator of smooth muscle
CC contraction by enhancing the calcium sensitivity to KCNMA1. Its
CC presence is also a requirement for internal binding of the KCNMA1
CC channel opener dehydrosoyasaponin I (DHS-1) triterpene glycoside and
CC for external binding of the agonist hormone 17-beta-estradiol (E2).
CC Increases the binding activity of charybdotoxin (CTX) toxin to KCNMA1
CC peptide blocker by increasing the CTX association rate and decreasing
CC the dissociation rate. {ECO:0000256|ARBA:ARBA00037578}.
CC -!- SUBUNIT: Interacts with KCNMA1 tetramer. There are probably 4 molecules
CC of KCMNB per KCNMA1 tetramer. {ECO:0000256|RuleBase:RU368097}.
CC -!- SUBUNIT: Interacts with KCNMA1 tetramer. There are probably 4 molecules
CC of KCMNB1 per KCNMA1 tetramer. {ECO:0000256|ARBA:ARBA00038556}.
CC -!- SUBCELLULAR LOCATION: Membrane {ECO:0000256|ARBA:ARBA00004141,
CC ECO:0000256|RuleBase:RU368097}; Multi-pass membrane protein
CC {ECO:0000256|ARBA:ARBA00004141, ECO:0000256|RuleBase:RU368097}.
CC -!- PTM: N-glycosylated. {ECO:0000256|RuleBase:RU368097}.
CC -!- SIMILARITY: Belongs to the KCNMB (TC 8.A.14.1) family. KCNMB1
CC subfamily. {ECO:0000256|ARBA:ARBA00038155}.
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DR RefSeq; XP_022348967.1; XM_022493259.1.
DR AlphaFoldDB; A0A2Y9IJZ3; -.
DR STRING; 391180.A0A2Y9IJZ3; -.
DR KEGG; elk:111140972; -.
DR OrthoDB; 4309705at2759; -.
DR Proteomes; UP000248482; Unplaced.
DR GO; GO:0008076; C:voltage-gated potassium channel complex; IEA:UniProtKB-UniRule.
DR GO; GO:0015269; F:calcium-activated potassium channel activity; IEA:UniProtKB-UniRule.
DR GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-UniRule.
DR GO; GO:0005513; P:detection of calcium ion; IEA:UniProtKB-UniRule.
DR InterPro; IPR003930; K_chnl_Ca-activ_BK_bsu.
DR PANTHER; PTHR10258; CALCIUM-ACTIVATED POTASSIUM CHANNEL SUBUNIT BETA; 1.
DR PANTHER; PTHR10258:SF1; CALCIUM-ACTIVATED POTASSIUM CHANNEL SUBUNIT BETA-1; 1.
DR Pfam; PF03185; CaKB; 1.
DR PRINTS; PR01450; BKCHANNELB.
PE 3: Inferred from homology;
KW Glycoprotein {ECO:0000256|RuleBase:RU368097};
KW Ion channel {ECO:0000256|RuleBase:RU368097,
KW ECO:0000313|RefSeq:XP_022348967.1};
KW Ion transport {ECO:0000256|RuleBase:RU368097};
KW Membrane {ECO:0000256|RuleBase:RU368097};
KW Reference proteome {ECO:0000313|Proteomes:UP000248482};
KW Transmembrane {ECO:0000256|RuleBase:RU368097};
KW Transmembrane helix {ECO:0000256|RuleBase:RU368097};
KW Transport {ECO:0000256|RuleBase:RU368097}.
FT TRANSMEM 16..34
FT /note="Helical"
FT /evidence="ECO:0000256|RuleBase:RU368097"
FT TRANSMEM 157..178
FT /note="Helical"
FT /evidence="ECO:0000256|RuleBase:RU368097"
SQ SEQUENCE 191 AA; 21839 MW; 50BCD0BB0D1C9DD4 CRC64;
MGKKLVMAQK RGETRALCLG VAMVVCAVIA YYILGTTMLP LYQKSVWTQK STCHLIETSI
REQEELEGKK VPQYPCLWVN VSAVGRWAVL YHTEDTRDQN QQCSYIPGSL ENYQVARADV
EKVRATFHEK QIFYCFSTTR ENETTVLYQR LYGPRTLLFS LFWPTFLLTG GLLIIAMVKI
NQSLSILAAQ K
//
