Download MendeleyMolecular Structure of the Na + ,K + -ATPase alpha 4 beta 1 Isoform in Its Ouabain-Bound Conformation.
Abe, K., McDermott, J., Valia Madapally, H., Marimuthu, P., Gopalasingam, C.C., Gerle, C., Shigematsu, H., Khandelia, H., Blanco, G.(2024) Int J Mol Sci 25
- PubMed: 39596464
- DOI: https://doi.org/10.3390/ijms252212397
- Primary Citation of Related Structures:
8ZYJ - PubMed Abstract:
Na + ,K + -ATPase is the active ion transport system that maintains the electrochemical gradients for Na + and K + across the plasma membrane of most animal cells. Na + ,K + -ATPase is constituted by the association of two major subunits, a catalytic α and a glycosylated β subunit, both of which exist as different isoforms (in mammals known as α1, α2, α3, α4, β1, β2 and β3). Na + ,K + -ATPase α and β isoforms assemble in different combinations to produce various isozymes with tissue specific expression and distinct biochemical properties. Na + ,K + -ATPase α4β1 is only found in male germ cells of the testis and is mainly expressed in the sperm flagellum, where it plays a critical role in sperm motility and male fertility. Here, we report the molecular structure of Na + ,K + -ATPase α4β1 at 2.37 Å resolution in the ouabain-bound state and in the presence of beryllium fluoride. Overall, Na + ,K + -ATPase α4 structure exhibits the basic major domains of a P-Type ATPase, resembling Na + ,K + -ATPase α1, but has differences specific to its distinct sequence. Dissimilarities include the site where the inhibitor ouabain binds. Molecular simulations indicate that glycosphingolipids can bind to a putative glycosphingolipid binding site, which could potentially modulate Na + ,K + -ATPase α4 activity. This is the first experimental evidence for the structure of Na + ,K + -ATPase α4β1. These data provide a template that will aid in better understanding the function Na + ,K + -ATPase α4β1 and will be important for the design and development of compounds that can modulate Na + ,K + -ATPase α4 activity for the purpose of improving male fertility or to achieve male contraception.
- Department of Chemistry, Faculty of Science, Hokkaido University, Hokkaido 060-0808, Japan.
Organizational Affiliation:
