First Author | Brukman NG | Year | 2023 |
Journal | J Cell Biol | Volume | 222 |
Issue | 2 | PubMed ID | 36394541 |
Mgi Jnum | J:333062 | Mgi Id | MGI:7386671 |
Doi | 10.1083/jcb.202207147 | Citation | Brukman NG, et al. (2023) A novel function for the sperm adhesion protein IZUMO1 in cell-cell fusion. J Cell Biol 222(2) |
abstractText | Mammalian sperm-egg adhesion depends on the trans-interaction between the sperm-specific type I glycoprotein IZUMO1 and its oocyte-specific GPI-anchored receptor JUNO. However, the mechanisms and proteins (fusogens) that mediate the following step of gamete fusion remain unknown. Using live imaging and content mixing assays in a heterologous system and structure-guided mutagenesis, we unveil an unexpected function for IZUMO1 in cell-to-cell fusion. We show that IZUMO1 alone is sufficient to induce fusion, and that this ability is retained in a mutant unable to bind JUNO. On the other hand, a triple mutation in exposed aromatic residues prevents this fusogenic activity without impairing JUNO interaction. Our findings suggest a second function for IZUMO1 as a unilateral mouse gamete fusogen. |