Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Membrane transport protein XK

Gene

XK

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

May be involved in sodium-dependent transport of neutral amino acids or oligopeptides.

GO - Molecular functioni

  • transporter activity Source: ProtInc

GO - Biological processi

Keywordsi

Molecular functionBlood group antigen
Biological processAmino-acid transport, Transport

Enzyme and pathway databases

ReactomeiR-HSA-375276 Peptide ligand-binding receptors

Protein family/group databases

TCDBi2.A.112.1.1 the kx blood-group antigen (kxa) family

Names & Taxonomyi

Protein namesi
Recommended name:
Membrane transport protein XK
Alternative name(s):
Kell complex 37 kDa component
Kx antigen
XK-related protein 1
Gene namesi
Name:XK
Synonyms:XKR1, XRG1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome X

Organism-specific databases

EuPathDBiHostDB:ENSG00000047597.5
HGNCiHGNC:12811 XK
MIMi314850 gene
neXtProtiNX_P51811

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 2CytoplasmicSequence analysis2
Transmembranei3 – 23HelicalSequence analysisAdd BLAST21
Topological domaini24 – 37ExtracellularSequence analysisAdd BLAST14
Transmembranei38 – 58HelicalSequence analysisAdd BLAST21
Topological domaini59 – 68CytoplasmicSequence analysis10
Transmembranei69 – 89HelicalSequence analysisAdd BLAST21
Topological domaini90 – 140ExtracellularSequence analysisAdd BLAST51
Transmembranei141 – 161HelicalSequence analysisAdd BLAST21
Topological domaini162 – 171CytoplasmicSequence analysis10
Transmembranei172 – 192HelicalSequence analysisAdd BLAST21
Topological domaini193 – 208ExtracellularSequence analysisAdd BLAST16
Transmembranei209 – 229HelicalSequence analysisAdd BLAST21
Topological domaini230 – 235CytoplasmicSequence analysis6
Transmembranei236 – 256HelicalSequence analysisAdd BLAST21
Topological domaini257 – 277ExtracellularSequence analysisAdd BLAST21
Transmembranei278 – 298HelicalSequence analysisAdd BLAST21
Topological domaini299 – 317CytoplasmicSequence analysisAdd BLAST19
Transmembranei318 – 338HelicalSequence analysisAdd BLAST21
Topological domaini339 – 349ExtracellularSequence analysisAdd BLAST11
Transmembranei350 – 370HelicalSequence analysisAdd BLAST21
Topological domaini371 – 444CytoplasmicSequence analysisAdd BLAST74

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Involvement in diseasei

McLeod syndrome (MLS)3 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA multisystem disorder characterized by the absence of red blood cell Kx antigen, weak expression of Kell red blood cell antigens, acanthocytosis, and compensated hemolysis. Most carriers of this McLeod blood group phenotype have acanthocytosis and elevated serum creatine kinase levels and are prone to develop a severe neurologic disorder resembling Huntington disease. Additional symptoms include generalized seizures, neuromuscular symptoms leading to weakness and atrophy, and cardiomyopathy mainly manifesting with atrial fibrillation, malignant arrhythmias, and dilated cardiomyopathy.
See also OMIM:300842
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_013817222R → G in MLS. 1 Publication1
Natural variantiVAR_013818294C → R in MLS. 1 PublicationCorresponds to variant dbSNP:rs28933690EnsemblClinVar.1
Natural variantiVAR_023581327E → K in MLS; atypical without hematologic, neuromuscular, or cerebral involvement. 1 Publication1

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi347C → S: Loss of Kell-XK complex. 1 Publication1

Keywords - Diseasei

Disease mutation

Organism-specific databases

DisGeNETi7504
GeneReviewsiXK
MalaCardsiXK
MIMi300842 phenotype
OpenTargetsiENSG00000047597
Orphaneti59306 McLeod neuroacanthocytosis syndrome
PharmGKBiPA37410

Polymorphism and mutation databases

BioMutaiXK
DMDMi85700269

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001907671 – 444Membrane transport protein XKAdd BLAST444

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei115PhosphoserineBy similarity1
Disulfide bondi347Interchain (with C-72 in Kell)1 Publication

Post-translational modificationi

Not glycosylated.

Keywords - PTMi

Disulfide bond, Phosphoprotein

Proteomic databases

EPDiP51811
MaxQBiP51811
PaxDbiP51811
PeptideAtlasiP51811
PRIDEiP51811
ProteomicsDBi56407

PTM databases

iPTMnetiP51811
PhosphoSitePlusiP51811
SwissPalmiP51811

Expressioni

Tissue specificityi

High levels in skeletal muscle, heart, brain, and pancreas; low levels in placenta, lung, liver, and kidney.

Gene expression databases

BgeeiENSG00000047597
CleanExiHS_XK
GenevisibleiP51811 HS

Organism-specific databases

HPAiHPA019036

Interactioni

Subunit structurei

Heterodimer with Kell; disulfide-linked.1 Publication

Protein-protein interaction databases

BioGridi113341, 7 interactors
IntActiP51811, 1 interactor
STRINGi9606.ENSP00000367879

Structurei

3D structure databases

ProteinModelPortaliP51811
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the XK family.Curated

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG410IE7C Eukaryota
ENOG410XP4P LUCA
GeneTreeiENSGT00390000003231
HOGENOMiHOG000118070
HOVERGENiHBG055838
InParanoidiP51811
KOiK19522
OMAiYAGINMF
OrthoDBiEOG091G07Y7
PhylomeDBiP51811
TreeFamiTF331465

Family and domain databases

InterProiView protein in InterPro
IPR018629 XK-rel
PfamiView protein in Pfam
PF09815 XK-related, 1 hit

Sequencei

Sequence statusi: Complete.

P51811-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MKFPASVLAS VFLFVAETTA ALSLSSTYRS GGDRMWQALT LLFSLLPCAL
60 70 80 90 100
VQLTLLFVHR DLSRDRPLVL LLHLLQLGPL FRCFEVFCIY FQSGNNEEPY
110 120 130 140 150
VSITKKRQMP KNGLSEEIEK EVGQAEGKLI THRSAFSRAS VIQAFLGSAP
160 170 180 190 200
QLTLQLYISV MQQDVTVGRS LLMTISLLSI VYGALRCNIL AIKIKYDEYE
210 220 230 240 250
VKVKPLAYVC IFLWRSFEIA TRVVVLVLFT SVLKTWVVVI ILINFFSFFL
260 270 280 290 300
YPWILFWCSG SPFPENIEKA LSRVGTTIVL CFLTLLYTGI NMFCWSAVQL
310 320 330 340 350
KIDSPDLISK SHNWYQLLVY YMIRFIENAI LLLLWYLFKT DIYMYVCAPL
360 370 380 390 400
LVLQLLIGYC TAILFMLVFY QFFHPCKKLF SSSVSEGFQR WLRCFCWACR
410 420 430 440
QQKPCEPIGK EDLQSSRDRD ETPSSSKTSP EPGQFLNAED LCSA
Length:444
Mass (Da):50,902
Last modified:January 24, 2006 - v5
Checksum:i6F90B0B45659A1DA
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti248F → L (Ref. 3) Curated1
Sequence conflicti248F → L (PubMed:15489334).Curated1

Polymorphismi

XK is responsible for the Kx blood group system.1 Publication

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_013817222R → G in MLS. 1 Publication1
Natural variantiVAR_013818294C → R in MLS. 1 PublicationCorresponds to variant dbSNP:rs28933690EnsemblClinVar.1
Natural variantiVAR_023581327E → K in MLS; atypical without hematologic, neuromuscular, or cerebral involvement. 1 Publication1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
Z32684 mRNA Translation: CAA83632.2
AY534238 mRNA Translation: AAT07087.1
DQ062746 Genomic DNA Translation: AAY43132.1
BC036019 mRNA Translation: AAH36019.1
CCDSiCCDS14241.1
PIRiI39294
RefSeqiNP_066569.1, NM_021083.3
UniGeneiHs.78919

Genome annotation databases

EnsembliENST00000378616; ENSP00000367879; ENSG00000047597
GeneIDi7504
KEGGihsa:7504
UCSCiuc004ddq.4 human

Similar proteinsi

Entry informationi

Entry nameiXK_HUMAN
AccessioniPrimary (citable) accession number: P51811
Secondary accession number(s): Q4TTN6, Q8IUK6, Q9UC77
Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 1, 1996
Last sequence update: January 24, 2006
Last modified: June 20, 2018
This is version 147 of the entry and version 5 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Blood group antigen proteins
    Nomenclature of blood group antigens and list of entries
  2. Human chromosome X
    Human chromosome X: entries, gene names and cross-references to MIM
  3. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  4. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  5. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  6. SIMILARITY comments
    Index of protein domains and families

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health