KRT74: Keratin 74 – A Key Structural Protein in Hair and Nail Development
Comprehensive genomic, proteomic, and clinical overview of KRT74, associated with autosomal dominant woolly hair and hypotrichosis.
Gene Information Card
| Symbol | KRT74 |
|---|---|
| Full Name | keratin 74 |
| Gene Type | protein-coding |
| Chromosomal Location | 12q13.13 |
| NCBI Gene ID | 121340 ncbi.nlm.nih.gov/gene/121340 |
| Ensembl ID | ENSG00000135446 |
| UniProt ID | Q7RTS7 |
| OMIM ID | 608248 |
| HGNC ID | 28929 |
| Aliases | KRT74, K6IRS2, KRT6IRS2, keratin 74 |
Description
KRT74 encodes keratin 74, a type II intermediate filament protein expressed specifically in the inner root sheath of hair follicles. This keratin is essential for the structural integrity of hair and nails. Mutations in KRT74 cause autosomal dominant woolly hair and hypotrichosis simplex, characterized by tightly curled, sparse hair. The gene is part of the keratin gene cluster on chromosome 12q13.13.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Woolly hair, autosomal dominant | Missense mutations disrupt keratin filament assembly, weakening hair shaft structure | OMIM #194300; ClinVar |
| Hypotrichosis simplex | Loss of functional keratin 74 impairs hair follicle integrity, leading to progressive hair loss | OMIM #146520; ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skin | 0.0 | Not detected |
| Hair follicle | High | Specific expression in inner root sheath |
| Esophagus | 0.0 | Not detected |
| Cervix | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HaCaT (keratinocyte) | 0.0 | No expression |
| NHEK (normal human epidermal keratinocytes) | 0.0 | No expression |
| Hair follicle dermal papilla cells | Low | Minimal expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.346G>A (p.Glu116Lys) | Missense | Rare | Dominant negative; disrupts keratin dimerization |
| c.374T>C (p.Leu125Pro) | Missense | Rare | Alters coiled-coil domain, filament instability |
| c.428A>G (p.Asn143Ser) | Missense | Rare | Impairs intermediate filament assembly |
Mutation functional classification
Loss of Function (LOF)
Not reported; KRT74 mutations are typically dominant negative rather than null.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Yes; missense mutations in the helix initiation motif disrupt filament formation, causing woolly hair.
View complete mutation data：
Gene Ontology (GO)
| • structural molecule activity | • intermediate filament organization |
| • keratin filament | • hair follicle development |
| • epidermis development |
Pathways
• Intermediate filament organization
• Keratinization
• Hair follicle morphogenesis
Protein Summary
Keratin 74 is a 55.8 kDa type II keratin that heteropolymerizes with type I keratins to form intermediate filaments in the inner root sheath of hair follicles. It contains a central alpha-helical rod domain with heptad repeats essential for coiled-coil dimerization. Mutations in this domain cause structural weakness, leading to woolly hair and hypotrichosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KRT74 Knockout HEK293 Cell Line | EDJ-KQ7992 | Human | 121391 | Details Get a Quote |
| KRT74 Knockout HeLa Cell Line | EDJ-KQ58085 | Human | 121391 | Details Get a Quote |
| KRT74 Knockout A-549 Cell Line | EDJ-KQ66572 | Human | 121391 | Details Get a Quote |
| KRT74 Knockout HCT 116 Cell Line | EDJ-KQ74988 | Human | 121391 | Details Get a Quote |
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