Seroatlas · Human Serome Atlas

KRT3

Keratin, type II cytoskeletal 3

Also known as: CK3, K2C3_HUMAN, K3

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

Protein identityUniProt · HPA

UniProt accession
P12035
Gene
KRT3
Ensembl
ENSG00000186442
Chromosome
12
Canonical length
628 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins

OverviewNCBI Gene

The protein encoded by this gene is a member of the keratin gene family. The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. This type II cytokeratin is specifically expressed in the corneal epithelium with family member KRT12 and mutations in these genes have been associated with Meesmann's Corneal Dystrophy. The type II cytokeratins are clustered in a region of chromosome 12q12-q13. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

628 residues, UniProt reviewed canonical sequence.

>P12035|KRT3
     1  MSRQASKTSG GGSQGFSGRS AVVSGSSRMS CVAHSGGAGG GAYGFRSGAG GFGSRSLYNL
    61  GGNKSISISV AAGGSRAGGF GGGRSSCAFA GGYGGGFGSG YGGGFGGGFG GGRGMGGGFG
   121  GAGGFGGAGG FGGAGGFGGP GGFGGSGGFG GPGSLGSPGG FGPGGFPGGI QEVTINQSLL
   181  QPLNVEIDPQ IGQVKAQERE QIKTLNNKFA SFIDKVRFLE QQNKVLETKW NLLQQQGTSS
   241  ISGTNNLEPL FENHINYLRS YLDNILGERG RLDSELKNME DLVEDFKKKY EDEINKRTAA
   301  ENEFVTLKKD VDSAYMNKVE LQAKVDALID EIDFLRTLYD AELSQMQSHI SDTSVVLSMD
   361  NNRSLDLDSI IAEVRAQYED IAQRSKAEAE ALYQTKLGEL QTTAGRHGDD LRNTKSEIIE
   421  LNRMIQRLRA EIEGVKKQNA NLQTAIAEAE QHGEMALKDA NAKLQELQAA LQQAKDDLAR
   481  LLRDYQELMN VKLALDVEIA TYRKLLEGEE YRMSGECPSA VSISVVSSST TSASAGGYGG
   541  GYGGGMGGGL GGGFSAGGGS GSGFGRGGGG GIGGGFGGGS SGFSGGSGFG SISGARYGVS
   601  GGGFSSASNR GGSIKFSQSS QSSQRYSR

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KRT3 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)
0.62
Highest tissue expression
10 nTPM

Expression across tissuesHPA

Tissue

  • salivary gland: 10 nTPM
  • esophagus: 2.9 nTPM
  • skin: 1.5 nTPM
  • vagina: 0.6 nTPM
  • cervix: 0.3 nTPM
  • tonsil: 0.2 nTPM

Single-cell type

  • ocular epithelial cells: 1,217 nCPM
  • suprabasal keratinocytes: 506 nCPM
  • basal keratinocytes: 12 nCPM
  • melanocytes: 9.4 nCPM
  • myosatellite cells: 9.3 nCPM
  • esophageal suprabasal cells: 9.2 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

  • cerebral cortex: 0.3 nTPM
  • hypothalamus: 0.3 nTPM
  • medulla oblongata: 0.2 nTPM
  • amygdala: 0.1 nTPM
  • basal ganglia: 0.1 nTPM
  • pons: 0.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about KRT3.

Disease | AllUniProt

Conditions KRT3 is implicated in, by any mechanism.

Disease | GeneticClinVar

5 pathogenic / likely-pathogenic of 173 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Corneal dystrophy, Meesmann, 2

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)
1.23
gnomAD pLI
0
gnomAD missense Z
0.07
DepMap mean gene effect
0.03
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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 KRT3 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 KRT3 as an antibody target. Whether an autoantibody or antibody against KRT3 could matter depends on whether native KRT3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KRT3 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 KRT3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/KRT3. 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).

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