New pre-print by Victoria & Andreas on sperm fertilization factors forming a trimer

29 Jul 2023

We are super excited about our new pre-print led by Victoria & Andreas in which we discover a conserved fertilization complex that mediates sperm-egg interaction in vertebrates. Using AlphaFold-based structural predictions to screen for protein-protein interactions amongst known fertilization factors and other gamete-expressed membrane or secreted proteins, we identified a trimeric complex consisting of the known sperm fertilization factors Izumo1 and Spaca6, and the newly discovered sperm factor Tmem81. We show that Tmem81 is indeed a newly identified essential fertilization factor in fish and in mice (a big thank you to our amazing collaborators Yonggang Lu and Masahito Ikawa at Osaka University, Japan). Crucially, AlphaFold Multimer predicts that this conserved trimeric complex on sperm interacts with the egg protein Bouncer in fish and JUNO in mammals, providing a molecular link between sperm and egg during fertilization. Big congratulations to everyone who contributed to this important work!