KERA Gene (Keratocan)
Keratocan: A Small Leucine-Rich Proteoglycan Critical for Corneal Transparency and Structure
Gene Information Card
| Symbol | KERA |
|---|---|
| Full Name | keratocan |
| Gene Type | protein-coding |
| Chromosomal Location | 12q21.33 |
| NCBI Gene ID | 11081 ncbi.nlm.nih.gov/gene/11081 |
| Ensembl ID | ENSG00000139330 |
| UniProt ID | Q60938 |
| OMIM ID | 603288 |
| HGNC ID | 6303 |
| Aliases | CNA2, SLRR2B, keratan sulfate proteoglycan |
Description
The KERA gene encodes keratocan, a member of the small leucine-rich proteoglycan (SLRP) family. Keratocan is a core protein of keratan sulfate proteoglycans, which are essential for maintaining corneal transparency, hydration, and extracellular matrix organization. Mutations in KERA cause autosomal recessive cornea plana type 2 (CNA2), a rare disorder characterized by corneal flattening, opacity, and hyperopia.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cornea plana 2 (CNA2) | Loss-of-function mutations in KERA disrupt keratan sulfate proteoglycan synthesis, leading to abnormal corneal collagen fibril spacing and reduced corneal curvature. | OMIM #217700; multiple reports in ClinVar and literature |
| Corneal dystrophy (unspecified) | Potential involvement in corneal opacity due to altered proteoglycan composition. | Limited evidence; case reports in NCBI GeneReviews |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Cornea | High (nTPM ~200) | High |
| Sclera | Moderate (nTPM ~50) | Moderate |
| Skin | Low (nTPM ~5) | Low |
| Cartilage | Low (nTPM ~3) | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Corneal fibroblasts | High | Primary cells; key for keratan sulfate synthesis |
| HEK293 | Low | Not endogenous; used for recombinant expression |
| HeLa | Not detected | No significant expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.741C>A (p.Cys247Ter) | Nonsense | Rare | Loss of function; truncation of keratocan protein |
| c.358G>A (p.Gly120Arg) | Missense | Rare | Loss of function; disrupts leucine-rich repeat domain |
| c.652C>T (p.Arg218Trp) | Missense | Rare | Loss of function; impairs proteoglycan assembly |
Mutation functional classification
Loss of Function (LOF)
Most KERA mutations are loss-of-function, leading to reduced or absent functional keratocan, causing cornea plana 2.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mechanisms described; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• KEGG hsa04512: ECM-receptor interaction
• Reactome R-HSA-3000178: ECM proteoglycans
Protein Summary
Keratocan is a 37 kDa secreted proteoglycan composed of a core protein with leucine-rich repeats and covalently attached keratan sulfate chains. It is predominantly expressed in the cornea and sclera, where it regulates collagen fibril diameter and spacing, contributing to tissue transparency and biomechanical strength. The protein interacts with other ECM components such as collagen type I and lumican.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KERA Knockout HEK293 Cell Line | EDJ-KQ7284 | Human | 11081 | Details Get a Quote |
| KERA Knockout HeLa Cell Line | EDJ-KQ55564 | Human | 11081 | Details Get a Quote |
| KERA Knockout A-549 Cell Line | EDJ-KQ64059 | Human | 11081 | Details Get a Quote |
| KERA Knockout HCT 116 Cell Line | EDJ-KQ72510 | Human | 11081 | Details Get a Quote |
