IZUMO1 Gene - Sperm-Oocyte Fusion Protein
Essential mediator of mammalian fertilization and sperm-egg fusion
Gene Information Card
| Symbol | IZUMO1 |
|---|---|
| Full Name | Izumo sperm-egg fusion 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 19q13.33 |
| NCBI Gene ID | 284359 ncbi.nlm.nih.gov/gene/284359 |
| Ensembl ID | ENSG00000182264 |
| UniProt ID | Q8IYV9 |
| OMIM ID | 609278 |
| HGNC ID | 28639 |
| Aliases | IZUMO, OBF, FLJ42837 |
Description
IZUMO1 encodes a transmembrane protein essential for sperm-egg fusion during fertilization. The protein is localized on the sperm acrosomal membrane and, following the acrosome reaction, relocates to the equatorial segment where it interacts with its oocyte receptor, JUNO (FOLR4). This interaction is critical for gamete fusion. IZUMO1 is testis-specific and highly conserved among mammals.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility due to sperm-oocyte fusion defect | Loss-of-function mutations in IZUMO1 prevent sperm-egg fusion, leading to fertilization failure | ClinVar, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 0.0 | Not expressed (nTPM data not available; RNA expression is testis-specific) |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Sperm cells | N/A | Protein detected on acrosomal membrane and equatorial segment |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | rare | Loss of start codon, likely loss of function |
| c.286C>T (p.Arg96*) | nonsense | rare | Premature stop, loss of function |
| c.424G>A (p.Gly142Arg) | missense | rare | Impaired binding to JUNO, reduced fusion |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt protein expression or JUNO binding lead to complete fertilization failure.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported; IZUMO1 acts as a monomer.
View complete mutation data：
Gene Ontology (GO)
| • single fertilization (GO:0007338) | • fusion of sperm to egg plasma membrane (GO:0007342) |
| • plasma membrane (GO:0005886) | • integral component of membrane (GO:0016021) |
| • protein binding (GO:0005515) |
Pathways
• Fertilization (Reactome: R-HSA-1187000)
Protein Summary
IZUMO1 is a type I transmembrane protein of 350 amino acids. It contains an N-terminal signal peptide, an extracellular domain with an immunoglobulin-like fold, a transmembrane helix, and a short cytoplasmic tail. The extracellular domain mediates binding to JUNO on the oocyte surface. The protein is N-glycosylated and forms a stable complex with other sperm proteins (e.g., SPACA6, DCST1/2) to facilitate membrane fusion.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| IZUMO1R Knockout HEK293 Cell Line | EDJ-KQ13136 | Human | 390243 | Details Get a Quote |
| IZUMO1 Knockout HEK293 Cell Line | EDJ-KQ13874 | Human | 284359 | Details Get a Quote |
| IZUMO1 Knockout HeLa Cell Line | EDJ-KQ59457 | Human | 284359 | Details Get a Quote |
| IZUMO1R Knockout HeLa Cell Line | EDJ-KQ60160 | Human | 390243 | Details Get a Quote |
| IZUMO1 Knockout A-549 Cell Line | EDJ-KQ67921 | Human | 284359 | Details Get a Quote |
| IZUMO1R Knockout A-549 Cell Line | EDJ-KQ68621 | Human | 390243 | Details Get a Quote |
| IZUMO1 Knockout HCT 116 Cell Line | EDJ-KQ76299 | Human | 284359 | Details Get a Quote |
| IZUMO1R Knockout HCT 116 Cell Line | EDJ-KQ76990 | Human | 390243 | Details Get a Quote |
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