Sperm-egg fusion protein Juno (Izumo1r)

Receptor for IZUMO1 present at the cell surface of oocytes (oolemma), which is essential for species-specific gamete fertilization and recognition. The IZUMO1:IZUMO1R/JUNO interaction is a essential adhesion event between egg and sperm that's required for fertilization but isn't sufficient for cell fusion.

The ligand-receptor interaction probably does not act as a membrane'fusogen'. Does not bind folate.