Download MendeleyStructure and mechanism of human vesicular polyamine transporter.
Guo, Y., Yang, G., Liu, H., Chai, J., Chen, J., Shanklin, J., Liu, Q., Liu, B., Lu, M.(2025) Nat Commun 16: 4142-4142
- PubMed: 40319071
- DOI: https://doi.org/10.1038/s41467-025-59549-w
- Primary Citation of Related Structures:
9D7U, 9D7V, 9D7W, 9D7X - PubMed Abstract:
Polyamines play essential roles in gene expression and modulate neuronal transmission in mammals. Vesicular polyamine transporters (VPAT) from the SLC18 family exploit the transmembrane H + gradient to translocate polyamines into secretory vesicles, enabling the quantal release of polyamine neuromodulators and underpinning learning and memory formation. Here, we report the cryo-electron microscopy structures of human VPAT in complex with spermine, spermidine, H + , or tetrabenazine, elucidating discrete lumen-facing states of the antiporter and pivotal interactions between VPAT and its substrate or inhibitor. Leveraging structure-inspired mutagenesis studies and protein structure prediction, we deduce an unforeseen mechanism whereby the polyamine and H + compete for multiple acidic protein residues both directly and indirectly, and rationalize how the antidopaminergic therapeutic tetrabenazine impedes vesicular transport of polyamines. This study unravels the mechanism of an H + -coupled polyamine antiporter, reveals mechanistic diversity between VPAT and other SLC18 antiporters, and raises new prospects for combating human disorders of polyamine homeostasis.
- Center for Proteomics & Molecular Therapeutics, Rosalind Franklin University of Medicine & Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA.
Organizational Affiliation:
