KRT19 (Keratin 19)
Type I Cytoskeletal Keratin, Intermediate Filament Protein
Gene Information Card
| Symbol | KRT19 |
|---|---|
| Full Name | Keratin 19 |
| Gene Type | Protein coding |
| Chromosomal Location | 17q21.2 |
| NCBI Gene ID | 3880 ncbi.nlm.nih.gov/gene/3880 |
| Ensembl ID | ENSG00000171345 |
| UniProt ID | P08727 |
| OMIM ID | 148020 |
| HGNC ID | 6429 |
| Aliases | CK19, K19, K1CS, MGC15366 |
Description
KRT19 (Keratin 19) encodes a type I cytokeratin, a member of the intermediate filament family. Keratin 19 is expressed in simple epithelia, including intestinal, pancreatic, biliary, and mammary epithelium. It is a key marker for circulating tumor cells (CTCs) and is frequently used in immunohistochemistry to detect epithelial-derived carcinomas. KRT19 expression is regulated during development and is often upregulated in cancers such as cholangiocarcinoma, pancreatic ductal adenocarcinoma, and breast cancer.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cholangiocarcinoma | Overexpression of KRT19 in bile duct epithelium promotes tumor cell invasion and metastasis. | PMID: 25695633 |
| Pancreatic Ductal Adenocarcinoma | KRT19 is a marker of aggressive tumor phenotype and correlates with poor prognosis. | PMID: 25964277 |
| Breast Cancer | KRT19-positive circulating tumor cells are associated with metastatic relapse and reduced survival. | PMID: 22962440 |
| Hepatocellular Carcinoma | KRT19 expression in hepatic progenitor cells indicates a more aggressive subtype. | PMID: 19177562 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Pancreas | 68.5 | High |
| Gallbladder | 55.2 | High |
| Breast | 42.1 | High |
| Liver | 12.3 | Medium |
| Colon | 8.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (Breast cancer) | 45.2 | High expression; used as positive control for KRT19 |
| PANC-1 (Pancreatic cancer) | 62.8 | High expression; correlates with invasive phenotype |
| HepG2 (Hepatocellular carcinoma) | 15.4 | Moderate expression |
| A549 (Lung cancer) | 3.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Likely loss of function; reported in ClinVar |
| c.315G>A (p.Trp105*) | Nonsense | <0.01% | Premature stop; loss of function |
| c.428C>T (p.Pro143Leu) | Missense | <0.01% | Uncertain significance; no functional data |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations in KRT19 are rare and predicted to cause haploinsufficiency, but no clear disease phenotype has been established.
Gain of Function (GOF)
No gain-of-function mutations have been reported for KRT19.
Dominant Negative (DN)
No dominant-negative mutations have been characterized for KRT19.
View complete mutation data：
Gene Ontology (GO)
| • structural molecule activity (GO:0005198) | • intermediate filament (GO:0005882) |
| • intermediate filament organization (GO:0045109) | • epithelial cell differentiation (GO:0030855) |
Pathways
• Intermediate filament organization (Reactome: R-HSA-6809371)
• Formation of the cornified envelope (Reactome: R-HSA-6809374)
Protein Summary
Keratin 19 (KRT19) is a 40 kDa type I intermediate filament protein that forms heteropolymers with type II keratins (e.g., KRT8, KRT18). It is expressed in simple epithelia and is a major component of the cytoskeleton. KRT19 is widely used as a biomarker for epithelial-derived tumors and circulating tumor cells. Its expression is regulated by transcription factors such as GATA6 and HNF1A. Post-translational modifications include phosphorylation, which modulates filament dynamics.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KRT19 Knockout HEK293 Cell Line | EDJ-KQ3214 | Human | 3880 | Details Get a Quote |
| KRT19 Knockout A-549 Cell Line | EDJ-KQ24691 | Human | 3880 | Details Get a Quote |
| KRT19 Knockout HCT 116 Cell Line | EDJ-KQ24692 | Human | 3880 | Details Get a Quote |
| KRT19 Knockout HeLa Cell Line | EDJ-KQ24693 | Human | 3880 | Details Get a Quote |
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