KRT20 Gene - Keratin 20
Intermediate filament protein involved in epithelial differentiation and cancer diagnostics
Gene Information Card
| Symbol | KRT20 |
|---|---|
| Full Name | Keratin 20 |
| Gene Type | Protein coding |
| Chromosomal Location | 17q21.2 |
| NCBI Gene ID | 54474 ncbi.nlm.nih.gov/gene/54474 |
| Ensembl ID | ENSG00000171428 |
| UniProt ID | P35900 |
| OMIM ID | 176270 |
| HGNC ID | 6442 |
| Aliases | CK20, K20, cytokeratin 20 |
Description
KRT20 (keratin 20) encodes a type I intermediate filament protein, cytokeratin 20, which is specifically expressed in gastrointestinal epithelium, urothelium, and Merkel cells. It forms heteropolymers with type II keratins and is a key marker for epithelial differentiation. KRT20 is widely used in immunohistochemistry for diagnosing colorectal carcinoma, Merkel cell carcinoma, and distinguishing primary from metastatic tumors. Its expression is regulated during development and altered in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Colorectal carcinoma | Loss of KRT20 expression correlates with tumor progression and poor prognosis; used as diagnostic marker | ClinVar, COSMIC |
| Merkel cell carcinoma | KRT20 is a specific immunohistochemical marker for Merkel cell carcinoma | NCBI, OMIM |
| Urothelial carcinoma | KRT20 expression is associated with invasive phenotype and recurrence | ClinVar |
| Pancreatic ductal adenocarcinoma | Aberrant KRT20 expression linked to metastasis | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Colon | 127.8 | High |
| Small intestine | 98.5 | High |
| Stomach | 45.2 | Medium |
| Urinary bladder | 32.1 | Medium |
| Skin (Merkel cells) | 15.6 | Low |
| Liver | 0.8 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Caco-2 (colon adenocarcinoma) | 156.3 | High expression; used as positive control |
| HT-29 (colorectal adenocarcinoma) | 112.7 | Moderate expression |
| MCF-7 (breast cancer) | 2.1 | Low expression |
| HeLa (cervical cancer) | 0.5 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.315G>A (p.Trp105*) | Nonsense | <0.1% | Loss of function; truncation |
| c.428C>T (p.Pro143Leu) | Missense | <0.1% | Unknown functional effect |
| c.1A>G (p.Met1?) | Start loss | <0.1% | Loss of translation initiation |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated protein; associated with reduced intermediate filament integrity.
Gain of Function (GOF)
No documented gain-of-function mutations in KRT20.
Dominant Negative (DN)
Not reported; KRT20 mutations are typically recessive or haploinsufficient.
View complete mutation data：
Gene Ontology (GO)
| • structural molecule activity (GO:0005198) | • intermediate filament (GO:0005882) |
| • keratin filament (GO:0045095) | • epithelial cell differentiation (GO:0030855) |
| • epidermis development (GO:0008544) |
Pathways
• Intermediate filament organization (Reactome: R-HSA-6809371)
• Keratinization (Reactome: R-HSA-6805567)
Protein Summary
Keratin 20 (KRT20) is a 424-amino acid type I intermediate filament protein with a molecular weight of ~48 kDa. It contains a central alpha-helical rod domain flanked by non-helical head and tail regions. KRT20 forms heteropolymeric filaments with type II keratins (e.g., KRT8) and provides mechanical stability to epithelial cells. Its expression is restricted to gastrointestinal epithelium, urothelium, and Merkel cells, making it a valuable diagnostic biomarker. Post-translational modifications include phosphorylation during cell division and apoptosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KRT20 Knockout HEK293 Cell Line | EDJ-KQ3237 | Human | 54474 | Details Get a Quote |
| KRT20 Knockout HCT 116 Cell Line | EDJ-KQ24749 | Human | 54474 | Details Get a Quote |
| KRT20 Knockout HeLa Cell Line | EDJ-KQ56421 | Human | 54474 | Details Get a Quote |
| KRT20 Knockout A-549 Cell Line | EDJ-KQ64916 | Human | 54474 | Details Get a Quote |
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