CRYBB3 (Crystallin Beta B3)
A structural lens protein gene associated with congenital cataracts
Gene Information Card
| Symbol | CRYBB3 |
|---|---|
| Full Name | Crystallin Beta B3 |
| Gene Type | Protein coding |
| Chromosomal Location | 22q11.23 |
| NCBI Gene ID | 1417 ncbi.nlm.nih.gov/gene/1417 |
| Ensembl ID | ENSG00000100053 |
| UniProt ID | P26998 |
| OMIM ID | 123630 |
| HGNC ID | 2399 |
| Aliases | CRYB3, CTRCT22, MGC141872 |
Description
CRYBB3 encodes beta-crystallin B3, a structural protein of the vertebrate eye lens. Beta-crystallins, together with gamma-crystallins, form the major soluble lens proteins and are critical for maintaining lens transparency and refractive index. Mutations in CRYBB3 cause autosomal recessive congenital cataracts, often with a pulverulent or nuclear phenotype.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital cataract (CTRCT22) | Loss-of-function mutations disrupt protein folding and lens transparency, leading to opacity | ClinVar, OMIM #123630 |
| Cataract 22, autosomal recessive | Homozygous or compound heterozygous missense/nonsense variants impair crystallin solubility | OMIM #609741 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lens | High | High |
| Retina | Low | Low |
| Brain | Not detected | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| ARPE-19 (retinal pigment epithelium) | 0.1 | Minimal expression |
| HLE-B3 (human lens epithelial) | High | Endogenous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.493C>T (p.Gln165*) | Nonsense | Rare | Premature truncation, loss of function |
| c.271G>A (p.Gly91Arg) | Missense | Rare | Altered protein stability, dominant-negative effect |
| c.1A>G (p.Met1?) | Start loss | Rare | No protein translation |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift variants leading to truncated or absent protein
Gain of Function (GOF)
Not reported
Dominant Negative (DN)
Missense mutations (e.g., p.Gly91Arg) that disrupt crystallin oligomerization
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of eye lens | • protein homodimerization activity |
| • identical protein binding |
Pathways
• Lens crystallin network
• Protein folding in lens
Protein Summary
Beta-crystallin B3 is a 25 kDa protein composed of four Greek-key motifs arranged in two domains. It forms homo- and heterodimers with other beta-crystallins, contributing to the high protein concentration and short-range order necessary for lens transparency. Post-translational modifications and aggregation of mutant CRYBB3 are linked to cataractogenesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CRYBB3 Knockout HEK293 Cell Line | EDJ-KQ4356 | Human | 1417 | Details Get a Quote |
| CRYBB3 Knockout HeLa Cell Line | EDJ-KQ52993 | Human | 1417 | Details Get a Quote |
| CRYBB3 Knockout A-549 Cell Line | EDJ-KQ61460 | Human | 1417 | Details Get a Quote |
| CRYBB3 Knockout HCT 116 Cell Line | EDJ-KQ69957 | Human | 1417 | Details Get a Quote |
