Seroatlas · Human Serome Atlas

KRT8

Keratin, type II cytoskeletal 8

Also known as: CARD2, CK-8, CK8, CYK8, K2C8, K2C8_HUMAN, K8, KO

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

Protein identityUniProt · HPA

UniProt accession: P05787
Gene: KRT8
Ensembl: ENSG00000170421
Chromosome: 12
Canonical length: 483 aa
Protein class: Cancer-related genes, Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins
Subcellular location: Intermediate filaments

OverviewNCBI Gene

This gene is a member of the type II keratin family clustered on the long arm of chromosome 12. Type I and type II keratins heteropolymerize to form intermediate-sized filaments in the cytoplasm of epithelial cells. The product of this gene typically dimerizes with keratin 18 to form an intermediate filament in simple single-layered epithelial cells. This protein plays a role in maintaining cellular structural integrity and also functions in signal transduction and cellular differentiation. Mutations in this gene cause cryptogenic cirrhosis. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jan 2012]

Canonical amino-acid sequenceUniProt

483 residues, UniProt reviewed canonical sequence.

>P05787|KRT8
     1  MSIRVTQKSY KVSTSGPRAF SSRSYTSGPG SRISSSSFSR VGSSNFRGGL GGGYGGASGM
    61  GGITAVTVNQ SLLSPLVLEV DPNIQAVRTQ EKEQIKTLNN KFASFIDKVR FLEQQNKMLE
   121  TKWSLLQQQK TARSNMDNMF ESYINNLRRQ LETLGQEKLK LEAELGNMQG LVEDFKNKYE
   181  DEINKRTEME NEFVLIKKDV DEAYMNKVEL ESRLEGLTDE INFLRQLYEE EIRELQSQIS
   241  DTSVVLSMDN SRSLDMDSII AEVKAQYEDI ANRSRAEAES MYQIKYEELQ SLAGKHGDDL
   301  RRTKTEISEM NRNISRLQAE IEGLKGQRAS LEAAIADAEQ RGELAIKDAN AKLSELEAAL
   361  QRAKQDMARQ LREYQELMNV KLALDIEIAT YRKLLEGEES RLESGMQNMS IHTKTTSGYA
   421  GGLSSAYGGL TSPGLSYSLG SSFGSGAGSS SFSRTSSSRA VVVKKIETRD GKLVSESSDV
   481  LPK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KRT8 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): 0.54
Highest tissue expression: 1,282 nTPM

Expression across tissuesHPA

Tissue

small intestine: 1,282 nTPM
duodenum: 1,067 nTPM
colon: 1,041 nTPM
stomach: 768 nTPM
pancreas: 578 nTPM
rectum: 554 nTPM

Single-cell type

colonocytes: 8,807 nCPM
extravillous trophoblasts: 6,860 nCPM
syncytiotrophoblasts: 6,236 nCPM
enterocytes: 5,865 nCPM
migrating cytotrophoblasts: 5,080 nCPM
goblet cells: 3,744 nCPM

Immune cell

plasmacytoid DC: 1.8 nTPM
basophil: 1.1 nTPM
myeloid DC: 0.8 nTPM
NK-cell: 0.5 nTPM
neutrophil: 0.4 nTPM
intermediate monocyte: 0.3 nTPM

Brain region

choroid plexus: 53 nTPM
pons: 24 nTPM
medulla oblongata: 16 nTPM
hypothalamus: 15 nTPM
midbrain: 15 nTPM
basal ganglia: 9.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KRT8.

Disease | AllUniProt

Conditions KRT8 is implicated in, by any mechanism.

Cirrhosis (CIRRH) MIM:215600

Disease | ImmuneIEDB

Conditions an epitope on KRT8 was assayed in.

ReferencesPubMed · IEDB

Publications for KRT8 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

4 publications

Profile identification of disease-associated humoral antigens using AMIDA, a novel proteomics-based technology.
2004 · Cell Mol Life Sci · RCR 1.2 · 57 citations
Anti-cytokeratin antibodies in sera of the patients with autoimmune hepatitis.
2001 · Clin Exp Immunol · RCR 0.6 · 23 citations
Evaluation of CK8-specific autoantibodies in carcinomas of distinct localisations.
2006 · Anticancer Res · RCR 0.2 · 6 citations
Autoantibodies in small fiber neuropathy: frequency and clinical features associated with antibodies to the novel targets MX1 and DBNL.
2026 · J Neurol

Reference: T cellIEDB

3 publications

T cell receptor fingerprinting enables in-depth characterization of the interactions governing recognition of peptide-MHC complexes.
2018 · Nat Biotechnol · RCR 2 · 73 citations
Immune responses to citrullinated and homocitrullinated peptides in healthy donors are not restricted to the HLA SE shared allele and can be selected into the memory pool.
2023 · Immunology · RCR 0.8 · 6 citations
Keratin 8 is a potential self-antigen in the coronary artery disease immunopeptidome: A translational approach.
2019 · PLoS One · RCR 0.5 · 12 citations

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): 1.07
gnomAD pLI: 0
gnomAD missense Z: 0.78
DepMap mean gene effect: -0.63
DepMap dependency class: common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

scaffold protein binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of KRT8 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 KRT8 as an antibody target. Whether an autoantibody or antibody against KRT8 could matter depends on whether native KRT8 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KRT8 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 KRT8 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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