Structure of a mammalian sperm cation channel complex.
Lin, S., Ke, M., Zhang, Y., Yan, Z., Wu, J.(2021) Nature 595: 746-750
- PubMed: 34225353 
- DOI: https://doi.org/10.1038/s41586-021-03742-6
- Primary Citation of Related Structures:  
7EEB - PubMed Abstract: 
The cation channel of sperm (CatSper) is essential for sperm motility and fertility 1,2 . CatSper comprises the pore-forming proteins CATSPER1-4 and multiple auxiliary subunits, including CATSPERβ, γ, δ, ε, ζ, and EFCAB9 1,3-9 . Here we report the cryo-electron microscopy (cryo-EM) structure of the CatSper complex isolated from mouse sperm. In the extracellular view, CATSPER1-4 conform to the conventional domain-swapped voltage-gated ion channel fold 10 , following a counterclockwise arrangement. The auxiliary subunits CATSPERβ, γ, δ and ε-each of which contains a single transmembrane segment and a large extracellular domain-constitute a pavilion-like structure that stabilizes the entire complex through interactions with CATSPER4, 1, 3 and 2, respectively. Our EM map reveals several previously uncharacterized components, exemplified by the organic anion transporter SLCO6C1. We name this channel-transporter ultracomplex the CatSpermasome. The assembly and organization details of the CatSpermasome presented here lay the foundation for the development of CatSpermasome-related treatments for male infertility and non-hormonal contraceptives.
Organizational Affiliation: 
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China.