ID   SCNNB_XENLA             Reviewed;         647 AA.
AC   P51169;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   25-MAY-2022, entry version 98.
DE   RecName: Full=Amiloride-sensitive sodium channel subunit beta;
DE   AltName: Full=Beta-NaCH;
DE   AltName: Full=Epithelial Na(+) channel subunit beta;
DE            Short=Beta-ENaC;
DE   AltName: Full=Nonvoltage-gated sodium channel 1 subunit beta;
DE   AltName: Full=SCNEB;
GN   Name=scnn1b-a;
OS   Xenopus laevis (African clawed frog).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX   NCBI_TaxID=8355;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, SUBUNIT, AND SUBCELLULAR LOCATION.
RC   TISSUE=Kidney;
RX   PubMed=7631745; DOI=10.1152/ajpcell.1995.269.1.c188;
RA   Puoti A., May A., Canessa C.M., Horisberger J.-D., Schild L., Rossier B.C.;
RT   "The highly selective low-conductance epithelial Na channel of Xenopus
RT   laevis A6 kidney cells.";
RL   Am. J. Physiol. 269:C188-C197(1995).
CC   -!- FUNCTION: Sodium permeable non-voltage-sensitive ion channel inhibited
CC       by the diuretic amiloride. Mediates the electrodiffusion of the luminal
CC       sodium (and water, which follows osmotically) through the apical
CC       membrane of epithelial cells. Plays an essential role in electrolyte
CC       and blood pressure homeostasis, but also in airway surface liquid
CC       homeostasis, which is important for proper clearance of mucus.
CC       {ECO:0000269|PubMed:7631745}.
CC   -!- SUBUNIT: Heterotrimer containing an alpha/SCNN1A, a beta/SCNN1B and a
CC       gamma/SCNN1G subunit. An additional delta/SCNN1D subunit exists only in
CC       some organisms and can replace the alpha/SCNN1A subunit to form an
CC       alternative channel with specific properties.
CC       {ECO:0000250|UniProtKB:P51168, ECO:0000269|PubMed:7631745}.
CC   -!- SUBCELLULAR LOCATION: Apical cell membrane
CC       {ECO:0000305|PubMed:7631745}; Multi-pass membrane protein
CC       {ECO:0000250|UniProtKB:P37089}. Cytoplasmic vesicle membrane
CC       {ECO:0000250|UniProtKB:P37090}. Note=Apical membrane of epithelial
CC       cells. {ECO:0000305|PubMed:7631745}.
CC   -!- SIMILARITY: Belongs to the amiloride-sensitive sodium channel (TC
CC       1.A.6) family. SCNN1B subfamily. {ECO:0000305}.
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DR   EMBL; U25285; AAA74971.1; -; mRNA.
DR   AlphaFoldDB; P51169; -.
DR   SMR; P51169; -.
DR   PRIDE; P51169; -.
DR   Proteomes; UP000186698; Genome assembly.
DR   GO; GO:0016324; C:apical plasma membrane; ISS:UniProtKB.
DR   GO; GO:0030659; C:cytoplasmic vesicle membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0005887; C:integral component of plasma membrane; ISS:UniProtKB.
DR   GO; GO:0034706; C:sodium channel complex; ISS:UniProtKB.
DR   GO; GO:0015280; F:ligand-gated sodium channel activity; IEA:InterPro.
DR   GO; GO:0050891; P:multicellular organismal water homeostasis; ISS:UniProtKB.
DR   GO; GO:0055078; P:sodium ion homeostasis; ISS:UniProtKB.
DR   GO; GO:0035725; P:sodium ion transmembrane transport; ISS:UniProtKB.
DR   InterPro; IPR001873; ENaC.
DR   InterPro; IPR004724; ENaC_chordates.
DR   InterPro; IPR020903; ENaC_CS.
DR   PANTHER; PTHR11690; PTHR11690; 1.
DR   Pfam; PF00858; ASC; 1.
DR   PRINTS; PR01078; AMINACHANNEL.
DR   TIGRFAMs; TIGR00859; ENaC; 1.
DR   PROSITE; PS01206; ASC; 1.
PE   1: Evidence at protein level;
KW   Cell membrane; Cytoplasmic vesicle; Ion channel; Ion transport; Membrane;
KW   Reference proteome; Sodium; Sodium channel; Sodium transport;
KW   Transmembrane; Transmembrane helix; Transport.
FT   CHAIN           1..647
FT                   /note="Amiloride-sensitive sodium channel subunit beta"
FT                   /id="PRO_0000181274"
FT   TOPO_DOM        1..57
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   TRANSMEM        58..78
FT                   /note="Helical; Name=1"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        79..552
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   TRANSMEM        553..573
FT                   /note="Helical; Name=2"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        574..647
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   REGION          586..647
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   647 AA;  73977 MW;  3A85366FB6DF3F16 CRC64;
     MIHGKMKRLK RYFTRALHRI QKGPGYTYKE LLVWFCDNTN THGPKRIIKE GPKKRVMWFI
     LTLVFAGLVF WQWGVLILTY LSYGVSVSLS IGFKTMEFPA VTLCNANPFK YSRVKPLLKE
     LDELVATALD RIQFSSQNQG NTFTHNNQTR QNVTLDPALW NHIPLVVIDE TDPRNPIIHN
     IFDNNAVYSK NSSIRNSSED QTSYSQRYKV AMKLCTNNNT QCVYRNFTSG VQALREWYLL
     QLSSIFSNVP LSGRIDMGFK AEDLILTCLF GGQPCSYRNF THIYDADYGN CYIFNWGQEG
     ENTMSSANPG ADFGLKLVLD IEQGEYLPFL QTTAAARLIL HQQRSFPFVK DLGIYAMPGT
     ETSISVLVDQ LEHMEAPYSS CTVNGSDIPV QNLYAEFNSS YSIQSCLRSC YQEEMVKTCK
     CAHYQYPLPN GSEYCTNMKH PDWVPCYYSL RDSVAIRENC ISLCQQPCND THYKMVISMA
     DWPSAGAEDW IFHVLSYEKD SSHNITVNRN GIVRLNIYFQ EFNYRSISES EATNVVWLLS
     NLGGQFGFWM GGSVLCIIEF GEIIIDCMWI TILKFLAWSR NRRQRRKRPQ YSDPPPTVSE
     LVEAHTNSGF QHDDGDHVPV DIPGTPPPNY DSLRVNTAEP VSSDEEN