A phase transition enhances the catalytic activity of SARM1, an NAD+ glycohydrolase involved in neurodegeneration
- University of Massachusetts Medical School, United States
Abstract
Sterile alpha and toll/interleukin receptor (TIR) motif-containing protein 1 (SARM1) is a neuronally expressed NAD+ glycohydrolase whose activity is increased in response to stress. NAD+ depletion triggers axonal degeneration, which is a characteristic feature of neurological diseases. Notably, loss of SARM1 is protective in murine models of peripheral neuropathy and traumatic brain injury. Herein, we report that citrate induces a phase transition that enhances SARM1 activity by ~2000-fold. This phase transition can be disrupted by mutating a residue involved in multimerization, G601P. This mutation also disrupts puncta formation in cells. We further show that citrate induces axonal degeneration in C. elegans that is dependent on the C. elegans orthologue of SARM1 (TIR-1). Notably, citrate induces the formation of larger puncta indicating that TIR-1/SARM1 multimerization is essential for degeneration in vivo. These findings provide critical insights into SARM1 biology with important implications for the discovery of novel SARM1-targeted therapeutics.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Funding
National Institute of General Medical Sciences (R35 GM118112)
- Paul R Thompson
National Institute of Neurological Disorders and Stroke (F31 NS108610)
- Heather S Loring
National Institute of Neurological Disorders and Stroke (R01 NS110936)
- Alexandra B Byrne
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Loring 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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A phase transition enhances the catalytic activity of SARM1, an NAD+ glycohydrolase involved in neurodegeneration
eLife 10:e66694.
https://doi.org/10.7554/eLife.66694
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