ID   SCNNB_NEOFS             Reviewed;         651 AA.
AC   H1AFJ6;
DT   27-MAY-2015, integrated into UniProtKB/Swiss-Prot.
DT   21-MAR-2012, sequence version 1.
DT   25-MAY-2022, entry version 26.
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; Synonyms=enacbeta {ECO:0000312|EMBL:BAL46407.1};
OS   Neoceratodus forsteri (Australian lungfish) (Ceratodus forsteri).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Dipnomorpha; Ceratodontiformes; Ceratodontoidei; Ceratodontidae;
OC   Neoceratodus.
OX   NCBI_TaxID=7892;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND TISSUE SPECIFICITY.
RC   TISSUE=Gill;
RX   PubMed=23055064; DOI=10.1098/rspb.2012.1945;
RA   Uchiyama M., Maejima S., Yoshie S., Kubo Y., Konno N., Joss J.M.P.;
RT   "The epithelial sodium channel in the Australian lungfish, Neoceratodus
RT   forsteri (Osteichthyes: Dipnoi).";
RL   Proc. R. Soc. B 279:4795-4802(2012).
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:23055064}.
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}.
CC   -!- SUBCELLULAR LOCATION: Apical cell membrane
CC       {ECO:0000250|UniProtKB:P37090}; 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:0000250|UniProtKB:P37090}.
CC   -!- TISSUE SPECIFICITY: Strongly expressed in gill, kidney and rectum and
CC       more weakly in brain, eye, liver and muscle.
CC       {ECO:0000269|PubMed:23055064}.
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; AB675923; BAL46407.1; -; mRNA.
DR   AlphaFoldDB; H1AFJ6; -.
DR   SMR; H1AFJ6; -.
DR   GO; GO:0016324; C:apical plasma membrane; ISS:UniProtKB.
DR   GO; GO:0030659; C:cytoplasmic vesicle membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0034706; C:sodium channel complex; IC:UniProtKB.
DR   GO; GO:0015280; F:ligand-gated sodium channel activity; IEA:InterPro.
DR   GO; GO:0035725; P:sodium ion transmembrane transport; IDA: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   2: Evidence at transcript level;
KW   Cell membrane; Cytoplasmic vesicle; Ion channel; Ion transport; Membrane;
KW   Sodium; Sodium channel; Sodium transport; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..651
FT                   /note="Amiloride-sensitive sodium channel subunit beta"
FT                   /id="PRO_0000433087"
FT   TOPO_DOM        1..50
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   TRANSMEM        51..71
FT                   /note="Helical; Name=1"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        72..541
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   TRANSMEM        542..562
FT                   /note="Helical; Name=2"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        563..651
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P37089"
FT   REGION          612..651
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        636..651
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   651 AA;  74207 MW;  BA7E0AD62380C6F9 CRC64;
     MFLKRWFIRA LHRLQKGPGY GYSELFVWYC NNTNTHGPKR LIIEGPKKKT LWSLFTVTFA
     CLVFWQWGLL IQTYLSWGVS VSLSVGFRGM DFPAVTVCNV NPFKYSKVKP LLKELDELVD
     ILLEQFYSYS TNGTLPVVFP DMRSSYLTGD PPPWYQIPLV MIDETDADNP TVTNVLGTDA
     LSPTNNSTTN SSTEARRYKV AFHLCNTNGT DCFYKNFSSS LEAVKEWYTL QYIDIISKLP
     LSQKVEMGYS GKDFILTCLF GGEACNYDNF TQFYHSSYGN CYVFNWGLDG NVLIVSNPGV
     GFGLQLALDV NQEEYIPFLT TRAGARFLLH TQNTFPFVET MGTYALVGTV TSVGILVDEV
     QRMGQPYGTC TTDGLDVPID NLYSQYNLSY TMQSCLWSCF QIQMVNSCGC AYYLYPLPEG
     ATYCNNQNNS DWAYCYYLLQ DSKDHKNECL QTCIQTCNEL QFRISTSMAD WPSESSEDWI
     FHVLSYERDD STNITMKRDG VLKLNLYFKE FNYRVITESV ATNVVWLLSN LGGQFGFWMG
     GSVLCIIEFG EVFIDCIWIA VIRFVKWYKN RKERQVQAQY ADPPPTVSEL VEGYTNQGFQ
     PDIINSCSPQ AQPPDLYLPT TLEIPGTPPP KYDSLRVHPI DTEHHSDSED L