Seroatlas · Human Serome Atlas

KRT18

Keratin, type I cytoskeletal 18

Also known as: K1C18_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P05783
Gene
KRT18
Ensembl
ENSG00000111057
Chromosome
12
Canonical length
430 aa
Protein class
Cancer-related genes, Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Cytosol

OverviewNCBI Gene

KRT18 encodes the type I intermediate filament chain keratin 18. Keratin 18, together with its filament partner keratin 8, are perhaps the most commonly found members of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic cirrhosis. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

430 residues, UniProt reviewed canonical sequence.

>P05783|KRT18
     1  MSFTTRSTFS TNYRSLGSVQ APSYGARPVS SAASVYAGAG GSGSRISVSR STSFRGGMGS
    61  GGLATGIAGG LAGMGGIQNE KETMQSLNDR LASYLDRVRS LETENRRLES KIREHLEKKG
   121  PQVRDWSHYF KIIEDLRAQI FANTVDNARI VLQIDNARLA ADDFRVKYET ELAMRQSVEN
   181  DIHGLRKVID DTNITRLQLE TEIEALKEEL LFMKKNHEEE VKGLQAQIAS SGLTVEVDAP
   241  KSQDLAKIMA DIRAQYDELA RKNREELDKY WSQQIEESTT VVTTQSAEVG AAETTLTELR
   301  RTVQSLEIDL DSMRNLKASL ENSLREVEAR YALQMEQLNG ILLHLESELA QTRAEGQRQA
   361  QEYEALLNIK VKLEAEIATY RRLLEDGEDF NLGDALDSSN SMQTIQKTTT RRIVDGKVVS
   421  ETNDTKVLRH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KRT18 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.53
Highest tissue expression
590 nTPM

Expression across tissuesHPA

Tissue

  • pancreas: 590 nTPM
  • liver: 535 nTPM
  • rectum: 462 nTPM
  • placenta: 446 nTPM
  • colon: 398 nTPM
  • small intestine: 349 nTPM

Single-cell type

  • syncytiotrophoblasts: 9,372 nCPM
  • migrating cytotrophoblasts: 7,757 nCPM
  • extravillous trophoblasts: 7,124 nCPM
  • tuft cells: 3,827 nCPM
  • cytotrophoblasts: 3,516 nCPM
  • goblet cells: 3,372 nCPM

Immune cell

  • basophil: 77 nTPM
  • naive CD4 T-cell: 11 nTPM
  • naive B-cell: 7.5 nTPM
  • memory B-cell: 4.6 nTPM
  • memory CD4 T-cell: 4.5 nTPM
  • naive CD8 T-cell: 4.1 nTPM

Brain region

  • choroid plexus: 73 nTPM
  • pons: 63 nTPM
  • medulla oblongata: 35 nTPM
  • hypothalamus: 28 nTPM
  • cerebellum: 10 nTPM
  • midbrain: 8.4 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KRT18.

Disease | AllUniProt

Conditions KRT18 is implicated in, by any mechanism.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 78 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Cirrhosis, cryptogenic
  • Cirrhosis, noncryptogenic, susceptibility to

Disease | ImmuneIEDB

Conditions an epitope on KRT18 was assayed in.

Disease | AutoantibodyPubMed

Conditions in which antibodies against KRT18 are reported. Each links to that disease's full target list.

    Showing 0 of 1 — disease pages carrying at least 10 antigens.

    ReferencesPubMed · IEDB

    Publications for KRT18 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

    Reference: AutoantibodyPubMed

    10 publications

    Show 5 more

    Reference: T cellIEDB

    5 publications

    Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. IEDB — curated epitope assays from the Immune Epitope Database (Vita et al., Nucleic Acids Research 2019). Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

    Genetic constraint and essentialitygnomAD · DepMap

    Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

    gnomAD LOEUF (loss-of-function intolerance)
    0.44
    gnomAD pLI
    0.73
    gnomAD missense Z
    1.04
    DepMap mean gene effect
    0.04
    DepMap dependency class
    selective

    Cancer expressionTCGA

    Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

    OntologyGO

    Biological processes

    Molecular functions

    Cellular components

    Protein domainsUniProt · Pfam · InterPro

    KeywordsUniProt

    InteractionsUniProt · HPA

    Protein binding partners of KRT18 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

    Antibody and autoantibody relevanceSeroatlas analysis

    Seroatlas reads KRT18 as an antibody target. Whether an autoantibody or antibody against KRT18 could matter depends on whether native KRT18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

    KRT18 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

    Annotation status

    The present source text does not explicitly label KRT18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

    Canonical record: https://seroatlas.com/gene/KRT18. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

    Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

    © 2026 · Seroatlas, Discover Oregon LLC · Terms of use

    Loading the interactive Seroatlas protein explorer...