ID   Q8IWS1_HUMAN            Unreviewed;       178 AA.
AC   Q8IWS1;
DT   01-MAR-2003, integrated into UniProtKB/TrEMBL.
DT   01-MAR-2003, sequence version 1.
DT   02-SEP-2026, entry version 83.
DE   RecName: Full=FXYD domain-containing ion transport regulator {ECO:0000256|RuleBase:RU364131};
GN   Name=KCT1 {ECO:0000313|EMBL:AAO13166.1};
OS   Homo sapiens (Human).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC   Homo.
OX   NCBI_TaxID=9606 {ECO:0000313|EMBL:AAO13166.1};
RN   [1] {ECO:0000313|EMBL:AAO13166.1}
RP   NUCLEOTIDE SEQUENCE.
RA   Bonkobara M., Takao J., Das A., Cruz P.D.Jr., Ariizumi K.;
RT   "Identification of genes for secreted and membrane-anchored proteins in
RT   keratinocytes.";
RL   Submitted (OCT-2002) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Associates with and regulates the activity of the
CC       sodium/potassium-transporting ATPase (NKA) which catalyzes the
CC       hydrolysis of ATP coupled with the exchange of Na(+) and K(+) ions
CC       across the plasma membrane. May increase NKA activity by increasing the
CC       apparent affinity for Na(+). Involved in down-regulation of E-cadherin
CC       which results in reduced cell adhesion. Promotes metastasis.
CC       {ECO:0000256|ARBA:ARBA00056439}.
CC   -!- SUBUNIT: Regulatory subunit of the sodium/potassium-transporting ATPase
CC       which is composed of a catalytic alpha subunit, a non-catalytic beta
CC       subunit and an additional regulatory subunit. The regulatory subunit, a
CC       member of the FXYD protein family, modulates the enzymatic activity in
CC       a tissue- and isoform-specific way by changing affinities of the
CC       Na+/K+-ATPase toward Na(+), K(+) or ATP.
CC       {ECO:0000256|ARBA:ARBA00064017}.
CC   -!- SUBCELLULAR LOCATION: Basolateral cell membrane
CC       {ECO:0000256|ARBA:ARBA00023768}; Single-pass type I membrane protein
CC       {ECO:0000256|ARBA:ARBA00023768}.
CC   -!- SIMILARITY: Belongs to the FXYD family. {ECO:0000256|ARBA:ARBA00005948,
CC       ECO:0000256|RuleBase:RU364131}.
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DR   EMBL; AY157582; AAO13166.1; -; mRNA.
DR   AlphaFoldDB; Q8IWS1; -.
DR   PeptideAtlas; Q8IWS1; -.
DR   ChiTaRS; FXYD5; human.
DR   GO; GO:0016323; C:basolateral plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-ARBA.
DR   GO; GO:0043269; P:regulation of monoatomic ion transport; IEA:InterPro.
DR   CDD; cd20323; FXYD_FXYD5; 1.
DR   FunFam; 1.20.5.780:FF:000005; FXYD domain-containing ion transport regulator; 1.
DR   Gene3D; 1.20.5.780; Single helix bin; 1.
DR   InterPro; IPR047297; FXYD_motif.
DR   InterPro; IPR000272; Ion-transport_regulator_FXYD.
DR   PANTHER; PTHR14132:SF14; FXYD DOMAIN-CONTAINING ION TRANSPORT REGULATOR 5; 1.
DR   PANTHER; PTHR14132; SODIUM/POTASSIUM-TRANSPORTING ATPASE SUBUNIT GAMMA; 1.
DR   Pfam; PF02038; ATP1G1_PLM_MAT8; 1.
DR   PROSITE; PS01310; FXYD; 1.
PE   2: Evidence at transcript level;
KW   Cell membrane {ECO:0000256|ARBA:ARBA00022475};
KW   Ion transport {ECO:0000256|ARBA:ARBA00023065,
KW   ECO:0000256|RuleBase:RU364131};
KW   Membrane {ECO:0000256|ARBA:ARBA00023136, ECO:0000256|RuleBase:RU364131};
KW   Potassium {ECO:0000256|ARBA:ARBA00022958};
KW   Potassium transport {ECO:0000256|ARBA:ARBA00022538};
KW   Signal {ECO:0000256|ARBA:ARBA00022729, ECO:0000256|RuleBase:RU364131};
KW   Sodium {ECO:0000256|ARBA:ARBA00023053};
KW   Sodium transport {ECO:0000256|ARBA:ARBA00023201};
KW   Sodium/potassium transport {ECO:0000256|ARBA:ARBA00022607};
KW   Transmembrane {ECO:0000256|ARBA:ARBA00022692,
KW   ECO:0000256|RuleBase:RU364131};
KW   Transmembrane helix {ECO:0000256|ARBA:ARBA00022989,
KW   ECO:0000256|RuleBase:RU364131};
KW   Transport {ECO:0000256|ARBA:ARBA00022448, ECO:0000256|RuleBase:RU364131}.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000256|RuleBase:RU364131"
FT   CHAIN           22..178
FT                   /note="FXYD domain-containing ion transport regulator"
FT                   /evidence="ECO:0000256|RuleBase:RU364131"
FT                   /id="PRO_5011330161"
FT   TRANSMEM        146..164
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU364131"
FT   REGION          23..128
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        26..36
FT                   /note="Low complexity"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        68..77
FT                   /note="Low complexity"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        103..121
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   178 AA;  19314 MW;  8129C0AD3A449584 CRC64;
     MSPSGRLCLL TIVGLILPTR GQTLKDTTSS SSADSTIMDI QVPTRAPDAV YTELQPTSPT
     PTWPADETPQ PQTQTQQLEG TDGPLVTDPE THKSTKAAHP TDDTTTLSER PSPSTDVQTD
     PQALKPSGFH EDDSFFYDEH TLRKRGLLVA AVLFITGIII LTSGKCGQLS RLCRNHCR
//