Sperm-egg fusion is facilitated by the sperm-specific receptor IZUMO1 and the egg-specific counter-receptor JUNO. Here Inoue et al.show that JUNO first binds to monomeric IZUMO1; IZUMO1 then dimerizes and excludes JUNO from the sperm-egg interface, suggesting the existence of a IZUMO1 dimer receptor.
- Naokazu Inoue
- Yoshihisa Hagihara
- Ikuo Wada