Post Translational Modifications | N-glycosylated. Glycosylation is not essential for fusion and for proper protein trafficking in sperm. Phosphorylated. The cytoplasmic C-terminus is phosphorylated and undergoes phosphorylation changes during epididymal transit. |
Function | Essential sperm cell-surface protein required for fertilization by acting as a ligand for IZUMO1R/JUNO receptor on egg. The IZUMO1:IZUMO1R/JUNO interaction is a necessary adhesion event between sperm and egg that is required for fertilization but is not sufficient for cell fusion. The ligand-receptor interaction probably does not act as a membrane 'fusogen'. Acts a ligand for the human-specific oolemma epitope FCRL3/MAIA during fertilization. FCRL3/MAIA replaces IZUMO1R/JUNO as IZUMO1 receptor after sperm-egg adhesion, which permits species-specific gamete fusion. |
Protein Name | Izumo Sperm-Egg Fusion Protein 1Oocyte Binding/Fusion FactorObfSperm-Specific Protein Izumo |
Database Links | Reactome: R-HSA-1300645 |
Cellular Localisation | Cell MembraneSingle-Pass Type I Membrane ProteinCytoplasmic VesicleSecretory VesicleAcrosome MembraneLocalizes Initially To The Acrosome Membrane Of The Sperm Head (Both Outer And Inner Acrosomal Membranes)During The Acrosome ReactionTranslocates To The Plasma Membrane |
Alternative Protein Names | Izumo Sperm-Egg Fusion Protein 1 proteinOocyte Binding/Fusion Factor proteinObf proteinSperm-Specific Protein Izumo proteinIZUMO1 protein |
Information sourced from Uniprot.org