TDP-43 forms amyloid filaments with a distinct fold in type A FTLD-TDP

Nature. 2023 Aug;620(7975):898-903. doi: 10.1038/s41586-023-06405-w. Epub 2023 Aug 2.


The abnormal assembly of TAR DNA-binding protein 43 (TDP-43) in neuronal and glial cells characterizes nearly all cases of amyotrophic lateral sclerosis (ALS) and around half of cases of frontotemporal lobar degeneration (FTLD)1,2. A causal role for TDP-43 assembly in neurodegeneration is evidenced by dominantly inherited missense mutations in TARDBP, the gene encoding TDP-43, that promote assembly and give rise to ALS and FTLD3-7. At least four types (A-D) of FTLD with TDP-43 pathology (FTLD-TDP) are defined by distinct brain distributions of assembled TDP-43 and are associated with different clinical presentations of frontotemporal dementia8. We previously showed, using cryo-electron microscopy, that TDP-43 assembles into amyloid filaments in ALS and type B FTLD-TDP9. However, the structures of assembled TDP-43 in FTLD without ALS remained unknown. Here we report the cryo-electron microscopy structures of assembled TDP-43 from the brains of three individuals with the most common type of FTLD-TDP, type A. TDP-43 formed amyloid filaments with a new fold that was the same across individuals, indicating that this fold may characterize type A FTLD-TDP. The fold resembles a chevron badge and is unlike the double-spiral-shaped fold of ALS and type B FTLD-TDP, establishing that distinct filament folds of TDP-43 characterize different neurodegenerative conditions. The structures, in combination with mass spectrometry, led to the identification of two new post-translational modifications of assembled TDP-43, citrullination and monomethylation of R293, and indicate that they may facilitate filament formation and observed structural variation in individual filaments. The structures of TDP-43 filaments from type A FTLD-TDP will guide mechanistic studies of TDP-43 assembly, as well as the development of diagnostic and therapeutic compounds for TDP-43 proteinopathies.

MeSH terms

  • Citrullination
  • Cryoelectron Microscopy
  • DNA-Binding Proteins* / chemistry
  • DNA-Binding Proteins* / metabolism
  • DNA-Binding Proteins* / ultrastructure
  • Frontotemporal Dementia* / metabolism
  • Frontotemporal Dementia* / pathology
  • Frontotemporal Lobar Degeneration* / classification
  • Frontotemporal Lobar Degeneration* / metabolism
  • Frontotemporal Lobar Degeneration* / pathology
  • Humans
  • Methylation


  • DNA-Binding Proteins
  • TARDBP protein, human