Abstract
In amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD), cytoplasmic aggregates of hyperphosphorylated TDP-43 accumulate and colocalize with some stress granule components, but how pathological TDP-43 aggregation is nucleated remains unknown. In Drosophila, we establish that downregulation of tankyrase, a poly(ADP-ribose) (PAR) polymerase, reduces TDP-43 accumulation in the cytoplasm and potently mitigates neurodegeneration. We establish that TDP-43 non-covalently binds to PAR via PAR-binding motifs embedded within its nuclear localization sequence. PAR binding promotes liquid-liquid phase separation of TDP-43 in vitro and is required for TDP-43 accumulation in stress granules in mammalian cells and neurons. Stress granule localization initially protects TDP-43 from disease-associated phosphorylation, but upon long-term stress, stress granules resolve, leaving behind aggregates of phosphorylated TDP-43. Finally, small-molecule inhibition of Tankyrase-1/2 in mammalian cells inhibits formation of cytoplasmic TDP-43 foci without affecting stress granule assembly. Thus, Tankyrase inhibition antagonizes TDP-43-associated pathology and neurodegeneration and could have therapeutic utility for ALS and FTD. McGurk et al. show that TDP-43 is a PAR-binding protein and that this function stimulates liquid-liquid phase separation and stress granule localization. Under short-term stress, the stress granule protects TDP-43 from phosphorylation. TDP-43 foci that persist during long-term stress transition into the phosphorylated state. Inhibition of the PARP Tankyrase mitigates both the cytoplasmic accumulation of TDP-43 and neuronal degeneration.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 703-717.e9 |
| Journal | Molecular cell |
| Volume | 71 |
| Issue number | 5 |
| DOIs | |
| State | Published - Sep 6 2018 |
Funding
We thank Yanlan Huang, Jeffrey Nirschl, and Yongqing Zhu for technical assistance. We thank Lindsey D. Goodman for reading the manuscript and for insightful comments, the CDB Microscopy Core at the University of Pennsylvania for the use of their Leica TCS SP8 confocal microscope, and Nicolas L. Fawzi (Brown University, USA) for the TDP-43-MBP-His 6 plasmid DNA. This work was funded by grants from the Ellison Medical Foundation (to L.G.), the American Federation for Aging Research (to L.G.), the Alzheimer’s Association (to L.G.), the Life Extension Foundation (to J.S.), the ALS Association (to J.S.), a Department of Biochemistry and Biophysics pilot grant (to J.S.), Target ALS (to J.S. and N.M.B.), the Glenn Foundation (to N.M.B.), the Robert Packard Center for ALS Research at Johns Hopkins (to J.S.), and NIH R01 NS095746-01 (to R.G.K.), R21NS093439 (to R.G.K.), 5R21NS087077-02 (to R.G.K.), R01GM099836 (to J.S.), R21NS090205 (to J.S.), 5R01NS073660 (to N.M.B.), and R35NS097275 (to N.M.B.). We thank Yanlan Huang, Jeffrey Nirschl, and Yongqing Zhu for technical assistance. We thank Lindsey D. Goodman for reading the manuscript and for insightful comments, the CDB Microscopy Core at the University of Pennsylvania for the use of their Leica TCS SP8 confocal microscope, and Nicolas L. Fawzi (Brown University, USA) for the TDP-43-MBP-His
Keywords
- ALS
- PARP
- PARylation
- TDP-43
- Tankyrase
- amyotrophic lateral sclerosis
- motor neuron disease
- phosphorylation
- poly(ADP-ribose)
- stress granule
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology