SPRR2B (Small Proline-Rich Protein 2B)
A cornified envelope precursor gene involved in epidermal barrier function and squamous cell differentiation.
Gene Information Card
| Symbol | SPRR2B |
|---|---|
| Full Name | Small Proline-Rich Protein 2B |
| Gene Type | Protein coding |
| Chromosomal Location | 1q21.3 |
| NCBI Gene ID | 6701 ncbi.nlm.nih.gov/gene/6701 |
| Ensembl ID | ENSG00000163349 |
| UniProt ID | P35326 |
| OMIM ID | 182268 |
| HGNC ID | 11263 |
| Aliases | SPRR2, SPRR2B, small proline-rich protein 2B |
Description
SPRR2B encodes a member of the small proline-rich protein family, which are components of the cornified cell envelope in stratified squamous epithelia. These proteins are cross-linked by transglutaminases during terminal differentiation of keratinocytes, contributing to the barrier function of skin and oral mucosa. SPRR2B expression is induced during inflammation and wound healing, and its dysregulation is observed in certain squamous cell carcinomas.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Squamous cell carcinoma (skin) | Overexpression of SPRR2B may contribute to altered cornified envelope assembly and tumor progression. | COSMIC; PMID: 10652318 |
| Psoriasis | Upregulated in psoriatic epidermis, possibly as part of aberrant differentiation. | NCBI Gene; PMID: 10652318 |
| Oral squamous cell carcinoma | Increased SPRR2B expression linked to differentiation status. | COSMIC; PMID: 10652318 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skin | 12.5 | Medium |
| Esophagus | 8.3 | Medium |
| Oral mucosa | 15.1 | High |
| Vagina | 10.2 | Medium |
| Lung | 0.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HaCaT (keratinocyte) | 14.2 | High expression in differentiated cells |
| A431 (epidermoid carcinoma) | 11.5 | Moderate expression |
| SCC-25 (oral squamous) | 9.8 | Moderate expression |
| HEK293 | 0.3 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Likely loss of start codon; effect unknown |
| c.124C>T (p.Arg42Cys) | Missense | <0.01% | Rare variant; no functional data |
| c.205G>A (p.Gly69Ser) | Missense | <0.01% | Rare variant; no functional data |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in ClinVar or COSMIC.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
No evidence for dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • cornified envelope | • keratinocyte differentiation |
| • structural constituent of skin epidermis | • transglutaminase substrate |
Pathways
• Keratinocyte differentiation
• Formation of the cornified envelope
Protein Summary
SPRR2B is a 73-amino-acid protein (8.5 kDa) rich in proline and glutamine, containing multiple repeats of the consensus sequence QQKQPCQPPV. It is cross-linked by transglutaminases to other envelope proteins (e.g., loricrin, involucrin) during terminal differentiation. The protein localizes to the cytoplasm and cell periphery of stratified squamous epithelial cells.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPRR2B Knockout HEK293 Cell Line | EDJ-KQ16780 | Human | 6701 | Details Get a Quote |
| SPRR2B Knockout HeLa Cell Line | EDJ-KQ54553 | Human | 6701 | Details Get a Quote |
| SPRR2B Knockout A-549 Cell Line | EDJ-KQ63037 | Human | 6701 | Details Get a Quote |
| SPRR2B Knockout HCT 116 Cell Line | EDJ-KQ71513 | Human | 6701 | Details Get a Quote |
