Abstract
TRPM2 is critically involved in diverse physiological processes including core temperature sensing, apoptosis, and immune response. TRPM2's activation by Ca2+ and ADP ribose (ADPR), an NAD+-metabolite produced under oxidative stress and neurodegenerative conditions, suggests a role in neurological disorders. We provide a central concept between triple-site ligand binding and the channel gating of human TRPM2. We show consecutive structural rearrangements and channel activation of TRPM2 induced by binding of ADPR in two indispensable locations, and the binding of Ca2+ in the transmembrane domain. The 8-Br-cADPR-an antagonist of cADPR-binds only to the MHR1/2 domain and inhibits TRPM2 by stabilizing the channel in an apo-like conformation. We conclude that MHR1/2 acts as a orthostatic ligand-binding site for TRPM2. The NUDT9-H domain binds to a second ADPR to assist channel activation in vertebrates, but not necessary in invertebrates. Our work provides insights into the gating mechanism of human TRPM2 and its pharmacology.
Data availability
All the cryo-EM data generated in this study will be deposited to PDB and EMDB databank.
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Human TRPM2 bound to 8-Br-cADPR and calciumProtein Data Bank, 6PUU.
Article and author information
Author details
Funding
Esther A. and Joseph Klingenstein Fund (2019 class)
- Juan Du
McKnight Endowment Fund for Neuroscience (2019 class)
- Juan Du
National Institutes of Health (R01NS111031)
- Juan Du
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Huang et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Ligand recognition and gating mechanism through three ligand-binding sites of human TRPM2 channel
eLife 8:e50175.
https://doi.org/10.7554/eLife.50175
