ESPN (Espin) Gene
Key regulator of actin cytoskeleton in stereocilia and microvilli
Gene Information Card
| Symbol | ESPN |
|---|---|
| Full Name | Espin |
| Gene Type | Protein coding |
| Chromosomal Location | 1p36.31 |
| NCBI Gene ID | 83715 ncbi.nlm.nih.gov/gene/83715 |
| Ensembl ID | ENSG00000187017 |
| UniProt ID | Q7Z406 |
| OMIM ID | 606351 |
| HGNC ID | 13281 |
| Aliases | DFNB36, USH1M, espin |
Description
The ESPN gene encodes espin, an actin-bundling protein essential for the formation and maintenance of stereocilia in inner ear hair cells and microvilli in other epithelial cells. Mutations in ESPN cause autosomal recessive deafness DFNB36 and a form of Usher syndrome type 1M (USH1M), characterized by congenital hearing loss and retinitis pigmentosa.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Deafness, autosomal recessive 36 (DFNB36) | Loss-of-function mutations in ESPN disrupt actin bundling in stereocilia, leading to hair cell degeneration and hearing loss. | OMIM #609006; multiple families reported |
| Usher syndrome type 1M (USH1M) | Biallelic ESPN mutations impair both cochlear and retinal function, causing combined hearing and vision loss. | OMIM #606351; ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Cochlea (inner ear) | High (RNA-seq) | High |
| Retina | 8.3 | Medium |
| Kidney | 6.1 | Low |
| Lung | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.2 | Moderate expression |
| HeLa | 9.8 | Low expression |
| SH-SY5Y | 7.5 | Low expression |
| Hair cell lines (e.g., UB/OC-1) | High | High expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1192C>T (p.Arg398*) | Nonsense | <0.01% | Premature stop; loss of actin-bundling function |
| c.682C>T (p.Arg228Cys) | Missense | <0.01% | Reduced actin binding; DFNB36 |
| c.2461C>T (p.Arg821Trp) | Missense | <0.01% | Associated with USH1M |
| c.1354delG (p.Glu452Lysfs*5) | Frameshift | <0.01% | Loss of function; hearing loss |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and splice-site mutations that truncate or destabilize espin, leading to DFNB36 and USH1M.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported; all known pathogenic ESPN mutations are recessive.
View complete mutation data：
Gene Ontology (GO)
| • actin binding (GO:0003779) | • actin filament bundle assembly (GO:0051015) |
| • actin cytoskeleton organization (GO:0030036) | • plasma membrane (GO:0005886) |
| • stereocilium (GO:0032420) |
Pathways
• Actin cytoskeleton regulation (Reactome R-HSA-5663222)
• Stereocilium morphogenesis (GO:0060088)
Protein Summary
Espin is a 854-amino acid actin-bundling protein containing multiple WH2 (WASP homology 2) domains and a C-terminal actin-binding domain. It cross-links actin filaments into tightly packed bundles, providing mechanical support to stereocilia and microvilli. Espin also interacts with other cytoskeletal regulators and is critical for sensory hair cell function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ESPN Knockout HEK293 Cell Line | EDJ-KQ9893 | Human | 83715 | Details Get a Quote |
| ESPNL Knockout HEK293 Cell Line | EDJ-KQ13328 | Human | 339768 | Details Get a Quote |
| ESPN Knockout HCT 116 Cell Line | EDJ-KQ36773 | Human | 83715 | Details Get a Quote |
| ESPNL Knockout HeLa Cell Line | EDJ-KQ42799 | Human | 339768 | Details Get a Quote |
| ESPN Knockout HeLa Cell Line | EDJ-KQ57472 | Human | 83715 | Details Get a Quote |
| ESPN Knockout A-549 Cell Line | EDJ-KQ65975 | Human | 83715 | Details Get a Quote |
| ESPNL Knockout A-549 Cell Line | EDJ-KQ68120 | Human | 339768 | Details Get a Quote |
| ESPNL Knockout HCT 116 Cell Line | EDJ-KQ76496 | Human | 339768 | Details Get a Quote |
