Direct activation of SARM1 by dsDNA is not supported by biochemical and cellular evidence
Sterile alpha and Toll/interleukin-1 receptor motif–containing protein 1 (SARM1) is a NAD + -consuming enzyme that drives axon degeneration and is activated by changes in the NMN/NAD + ratio. A recent study proposed that cytosolic double-stranded DNA (dsDNA) directly binds SARM1’s TIR domain, activating it independently of this canonical mechanism. Here, we evaluate dsDNA-dependent SARM1 activation using purified SARM1, biochemical and biophysical assays, primary neurons, and cellular pharmacology. Across multiple platforms, dsDNA does not stimulate SARM1 NADase activity, promote higher-order assembly, or generate the metabolic signature of activated SARM1. When effects are observed, they are weak, context-dependent, and inconsistent across assays, and do not support a defined activation mechanism. In cells, dsDNA induces NAD + depletion through PARP-dependent pathways independently of SARM1. The reported DNA-binding mutant (3KE-SARM1) is nonfunctional in canonical SARM1 activation paradigms such as axotomy and therefore cannot be used to infer dsDNA activation mechanisms. Together, these findings do not support a model in which SARM1 is directly activated by dsDNA.
Authors
- Jeffrey Milbrandt (ORCID: https://orcid.org/0000-0002-5477-7689)
- Mitchell Sorbello (ORCID: https://orcid.org/0000-0001-9442-5170)
- Giuseppe Orsomando (ORCID: https://orcid.org/0000-0001-6640-097X)
- Aaron DiAntonio (ORCID: https://orcid.org/0000-0002-7262-0968)
- Weixi Gu (ORCID: https://orcid.org/0000-0002-1185-3557)
- Biswa Prasanna Mishra (ORCID: https://orcid.org/0000-0001-7069-3138)
- Boštjan Kobe (ORCID: https://orcid.org/0000-0001-9413-9166)
- Yong Zhao (ORCID: https://orcid.org/0000-0003-4564-1912)
- Yuefeng Jiang (ORCID: https://orcid.org/0000-0003-3985-2027)
- Thomas Ve (ORCID: https://orcid.org/0000-0002-0113-1905)
- Allison Kao
- Qinyi Zhou
- Veronika Masic (ORCID: https://orcid.org/0000-0001-9004-1030)
- Robi D. Mitra (ORCID: https://orcid.org/0000-0002-2680-4264)
- Xiaodong Wang (ORCID: https://orcid.org/0000-0001-9885-356X)
- Zhe Zhang (ORCID: https://orcid.org/0000-0002-4932-4343)
- Wenbin Zhang (ORCID: https://orcid.org/0000-0003-3024-5415)
- Jian Yuan Yang
- Paige Harten
- A. Joseph Bloom
Institutions
- Griffith University (AU)
- Marche Polytechnic University (IT)
- The University of Queensland (AU)
- Chinese University of Hong Kong (HK)
- National Institute of Biological Sciences, Beijing (CN)
- Institute for Biomedicine (IT)
- AgriBio (AU)
- Center for Life Sciences (CN)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2026-09-11
- DOI
- https://doi.org/10.1073/pnas.2620112123
- Primary Topic
- Sirtuins and Resveratrol in Medicine
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Ministry of Science and Technology of the People's Republic of China
- National Institutes of Health
- National Health and Medical Research Council
- Beijing Municipal Natural Science Foundation