KRT78: Keratin 78
A type II keratin gene involved in epithelial integrity and skin disorders
Gene Information Card
| Symbol | KRT78 |
|---|---|
| Full Name | Keratin 78 |
| Gene Type | Protein coding |
| Chromosomal Location | 12q13.13 |
| NCBI Gene ID | 196374 ncbi.nlm.nih.gov/gene/196374 |
| Ensembl ID | ENSG00000170423 |
| UniProt ID | Q8N1N4 |
| OMIM ID | 616002 |
| HGNC ID | 28927 |
| Aliases | K5B, KRT5B, keratin 5B |
Description
KRT78 encodes keratin 78, a type II (basic) keratin that forms heterodimers with type I keratins to assemble intermediate filaments in epithelial cells. It is expressed in stratified epithelia and contributes to mechanical resilience and cellular integrity. Mutations in KRT78 are associated with skin fragility disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Epidermolysis bullosa simplex (EBS) | Disruption of keratin filament assembly due to KRT78 mutations leads to epidermal fragility and blistering | ClinVar, OMIM |
| Palmoplantar keratoderma | Altered keratin network in palmoplantar epidermis causes hyperkeratosis and thickening | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skin | 12.5 | Medium |
| Esophagus | 8.2 | Low |
| Oral mucosa | 7.1 | Low |
| Vagina | 6.8 | Low |
| Breast | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HaCaT (keratinocyte) | 15.3 | High expression in immortalized keratinocytes |
| A431 (epidermoid carcinoma) | 10.1 | Moderate expression |
| MCF7 (breast cancer) | 0.8 | 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 | Loss of start codon, likely loss of function |
| c.2T>C (p.Met1Thr) | Missense | Rare | Alters initiation codon, reduced protein expression |
| c.3G>A (p.Met1Ile) | Missense | Rare | Impaired translation initiation |
Mutation functional classification
Loss of Function (LOF)
Mutations affecting the start codon or introducing premature stop codons lead to haploinsufficiency and keratin filament instability.
Gain of Function (GOF)
No evidence of gain-of-function mutations in KRT78.
Dominant Negative (DN)
Missense mutations in the rod domain may disrupt filament assembly in a dominant-negative manner, as seen in other keratins.
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 78 is a 58 kDa type II keratin that pairs with type I keratins (e.g., K14) to form intermediate filaments in the basal layer of stratified epithelia. It provides mechanical strength and is essential for maintaining epidermal integrity. The protein contains a central alpha-helical rod domain flanked by non-helical head and tail regions.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KRT78 Knockout HEK293 Cell Line | EDJ-KQ13979 | Human | 196374 | Details Get a Quote |
| KRT78 Knockout HeLa Cell Line | EDJ-KQ58967 | Human | 196374 | Details Get a Quote |
| KRT78 Knockout A-549 Cell Line | EDJ-KQ67454 | Human | 196374 | Details Get a Quote |
| KRT78 Knockout HCT 116 Cell Line | EDJ-KQ75848 | Human | 196374 | Details Get a Quote |
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