Cell Reports (Jan 2025)

Opposing roles of p38α-mediated phosphorylation and PRMT1-mediated arginine methylation in driving TDP-43 proteinopathy

  • Mari Aikio,
  • Hana M. Odeh,
  • Heike J. Wobst,
  • Bo Lim Lee,
  • Úna Chan,
  • Jocelyn C. Mauna,
  • Korrie L. Mack,
  • Bradley Class,
  • Thomas A. Ollerhead,
  • Alice F. Ford,
  • Edward M. Barbieri,
  • Ryan R. Cupo,
  • Lauren E. Drake,
  • Joshua L. Smalley,
  • Yuan-Ta Lin,
  • Stephanie Lam,
  • Reuben Thomas,
  • Nicholas Castello,
  • Ashmita Baral,
  • Jenna N. Beyer,
  • Mohd A. Najar,
  • John Dunlop,
  • Aaron D. Gitler,
  • Ashkan Javaherian,
  • Julia A. Kaye,
  • George M. Burslem,
  • Dean G. Brown,
  • Christopher J. Donnelly,
  • Steven Finkbeiner,
  • Stephen J. Moss,
  • Nicholas J. Brandon,
  • James Shorter

Journal volume & issue
Vol. 44, no. 1
p. 115205

Abstract

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Summary: Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder typically characterized by insoluble inclusions of hyperphosphorylated TDP-43. The mechanisms underlying toxic TDP-43 accumulation are not understood. Persistent activation of p38 mitogen-activated protein kinase (MAPK) is implicated in ALS. However, it is unclear how p38 MAPK affects TDP-43 proteinopathy. Here, we show that p38α MAPK inhibition reduces pathological TDP-43 phosphorylation, aggregation, cytoplasmic mislocalization, and neurotoxicity. Remarkably, p38α MAPK inhibition mitigates aberrant TDP-43 phenotypes in diverse ALS patient-derived motor neurons. p38α MAPK phosphorylates TDP-43 at pathological S409/S410 and S292, which reduces TDP-43 liquid-liquid phase separation (LLPS) but allows pathological TDP-43 aggregation. Moreover, we establish that PRMT1 methylates TDP-43 at R293. Importantly, S292 phosphorylation reduces R293 methylation, and R293 methylation reduces S409/S410 phosphorylation. Notably, R293 methylation permits TDP-43 LLPS and reduces pathological TDP-43 aggregation. Thus, strategies to reduce p38α-mediated TDP-43 phosphorylation and promote PRMT1-mediated R293 methylation could have therapeutic utility for ALS and related TDP-43 proteinopathies.

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