Seroatlas · Human Serome Atlas

KCNJ18

Inward rectifier potassium channel 18

Also known as: KCJ18_HUMAN, KIR2.6, TTPP2

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: B7U540
Gene: KCNJ18
Ensembl: ENSG00000260458
Chromosome: 17
Canonical length: 433 aa
Protein class: Disease related genes, Human disease related genes, Predicted membrane proteins
Subcellular location: Nucleoplasm,Golgi apparatus,Cytosol

OverviewNCBI Gene

This gene encodes a member of the inwardly rectifying potassium channel family. Transcription of this locus is regulated by thyroid hormone, and the encoded protein plays a role in resting membrane potential maintenance. Mutations in this locus have been associated with thyrotoxic hypokalemic periodic paralysis. [provided by RefSeq, Jan 2013]

Canonical amino-acid sequenceUniProt

433 residues, UniProt reviewed canonical sequence.

>B7U540|KCNJ18
     1  MTAASRANPY SIVSLEEDGL HLVTMSGANG FGNGKVHTRR RCRNRFVKKN GQCNIAFANM
    61  DEKSQRYLAD MFTTCVDIRW RYMLLIFSLA FLASWLLFGV IFWVIAVAHG DLEPAEGHGR
   121  TPCVMQVHGF MAAFLFSIET QTTIGYGLRC VTEECLVAVF MVVAQSIVGC IIDSFMIGAI
   181  MAKMARPKKR AQTLLFSHNA VVALRDGKLC LMWRVGNLRK SHIVEAHVRA QLIKPRVTEE
   241  GEYIPLDQID IDVGFDKGLD RIFLVSPITI LHEIDEASPL FGISRQDLET DDFEIVVILE
   301  GMVEATAMTT QARSSYLANE ILWGHRFEPV LFEEKNQYKI DYSHFHKTYE VPSTPRCSAK
   361  DLVENKFLLP SANSFCYENE LAFLSRDEED EADGDQDGRS RDGLSPQARH DFDRLQAGGG
   421  VLEQRPYRRG SEI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KCNJ18 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Cell surface
Secreted: No
Transmembrane segments: 2
Mean surface accessibility (rSASA): 0.41
Highest tissue expression: 7.3 nTPM

Expression across tissuesHPA

Tissue

skin: 7.3 nTPM
tonsil: 1.4 nTPM
testis: 0.5 nTPM
breast: 0.1 nTPM
cervix: 0.1 nTPM
adipose tissue: 0 nTPM

Single-cell type

conjunctival goblet cells: 1.9 nCPM
suprabasal keratinocytes: 1.4 nCPM
esophageal apical cells: 0.9 nCPM
respiratory secretory cells: 0.9 nCPM
late spermatids: 0.7 nCPM
endometrial secretory cells: 0.6 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

cerebellum: 0.1 nTPM
cerebral cortex: 0.1 nTPM
amygdala: 0 nTPM
basal ganglia: 0 nTPM
choroid plexus: 0 nTPM
hippocampal formation: 0 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KCNJ18.

Disease | AllUniProt

Conditions KCNJ18 is implicated in, by any mechanism.

Thyrotoxic periodic paralysis 2 (TTPP2) MIM:613239

OntologyGO

Biological processes

Molecular functions

inward rectifier potassium channel activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads KCNJ18 as an antibody target. Whether an autoantibody or antibody against KCNJ18 could matter depends on whether native KCNJ18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KCNJ18 is annotated at the cell surface, where native KCNJ18 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label KCNJ18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...