Seroatlas · Human Serome Atlas

KRT20

Keratin, type I cytoskeletal 20

Also known as: CK20, K1C20_HUMAN, K20, MGC35423

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

Protein identityUniProt · HPA

UniProt accession: P35900
Gene: KRT20
Ensembl: ENSG00000171431
Chromosome: 17
Canonical length: 424 aa
Protein class: Plasma proteins, Predicted intracellular proteins
Subcellular location: Intermediate filaments,Cytosol

OverviewNCBI Gene

The protein encoded by this gene is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. This cytokeratin is a major cellular protein of mature enterocytes and goblet cells and is specifically expressed in the gastric and intestinal mucosa. The type I cytokeratin genes are clustered in a region of chromosome 17q12-q21. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

424 residues, UniProt reviewed canonical sequence.

>P35900|KRT20
     1  MDFSRRSFHR SLSSSLQAPV VSTVGMQRLG TTPSVYGGAG GRGIRISNSR HTVNYGSDLT
    61  GGGDLFVGNE KMAMQNLNDR LASYLEKVRT LEQSNSKLEV QIKQWYETNA PRAGRDYSAY
   121  YRQIEELRSQ IKDAQLQNAR CVLQIDNAKL AAEDFRLKYE TERGIRLTVE ADLQGLNKVF
   181  DDLTLHKTDL EIQIEELNKD LALLKKEHQE EVDGLHKHLG NTVNVEVDAA PGLNLGVIMN
   241  EMRQKYEVMA QKNLQEAKEQ FERQTAVLQQ QVTVNTEELK GTEVQLTELR RTSQSLEIEL
   301  QSHLSMKESL EHTLEETKAR YSSQLANLQS LLSSLEAQLM QIRSNMERQN NEYHILLDIK
   361  TRLEQEIATY RRLLEGEDVK TTEYQLSTLE ERDIKKTRKI KTVVQEVVDG KVVSSEVKEV
   421  EENI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against KRT20 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: 610 nTPM

Expression across tissuesHPA

Tissue

small intestine: 610 nTPM
colon: 560 nTPM
rectum: 451 nTPM
duodenum: 279 nTPM
stomach: 118 nTPM
appendix: 47 nTPM

Single-cell type

colonocytes: 113 nCPM
enterocytes: 79 nCPM
urothelial cells: 38 nCPM
goblet cells: 24 nCPM
neuroendocrine cells: 21 nCPM
foveolar cells: 13 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

amygdala: 0.2 nTPM
cerebral cortex: 0.2 nTPM
white matter: 0.2 nTPM
basal ganglia: 0.1 nTPM
hippocampal formation: 0.1 nTPM
hypothalamus: 0.1 nTPM

ReferencesPubMed · IEDB

Publications for KRT20 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

1 publication

Autoantibody profiling using microarray identifies biomarkers associated with chemoimmunotherapy efficacy and immune-related adverse events in lung cancer patients.
2025 · Clin Exp Med · 2 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. 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): 1.3
gnomAD pLI: 0
gnomAD missense Z: 0.37
DepMap mean gene effect: -0.02
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 KRT20 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 KRT20 as an antibody target. Whether an autoantibody or antibody against KRT20 could matter depends on whether native KRT20 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

KRT20 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 KRT20 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...