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Title | Heteromeric amyloid filaments of ANXA11 and TDP-43 in FTLD-TDP Type C. |
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Journal, issue, pages | bioRxiv, Year 2024 |
Publish date | Jun 26, 2024 |
Authors | Diana Arseni / Takashi Nonaka / Max H Jacobsen / Alexey G Murzin / Laura Cracco / Sew Y Peak-Chew / Holly J Garringer / Ito Kawakami / Hisaomi Suzuki / Misumoto Onaya / Yuko Saito / Shigeo Murayama / Changiz Geula / Ruben Vidal / Kathy L Newell / Marsel Mesulam / Bernardino Ghetti / Masato Hasegawa / Benjamin Ryskeldi-Falcon |
PubMed Abstract | Neurodegenerative diseases are characterised by the abnormal filamentous assembly of specific proteins in the central nervous system . Human genetic studies established a causal role for protein ...Neurodegenerative diseases are characterised by the abnormal filamentous assembly of specific proteins in the central nervous system . Human genetic studies established a causal role for protein assembly in neurodegeneration . However, the underlying molecular mechanisms remain largely unknown, which is limiting progress in developing clinical tools for these diseases. Recent advances in electron cryo-microscopy (cryo-EM) have enabled the structures of the protein filaments to be determined from patient brains . All diseases studied to date have been characterised by the self-assembly of a single intracellular protein in homomeric amyloid filaments, including that of TAR DNA-binding protein 43 (TDP-43) in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) Types A and B . Here, we used cryo-EM to determine filament structures from the brains of individuals with FTLD-TDP Type C, one of the most common forms of sporadic FTLD-TDP. Unexpectedly, the structures revealed that a second protein, annexin A11 (ANXA11), co-assembles with TDP-43 in heteromeric amyloid filaments. The ordered filament fold is formed by TDP-43 residues G282/284-N345 and ANXA11 residues L39-L74 from their respective low-complexity domains (LCDs). Regions of TDP-43 and ANXA11 previously implicated in protein-protein interactions form an extensive hydrophobic interface at the centre of the filament fold. Immunoblots of the filaments revealed that the majority of ANXA11 exists as a ∼22 kDa N-terminal fragment (NTF) lacking the annexin core domain. Immunohistochemistry of brain sections confirmed the co-localisation of ANXA11 and TDP-43 in inclusions, redefining the histopathology of FTLD-TDP Type C. This work establishes a central role for ANXA11 in FTLD-TDP Type C. The unprecedented formation of heteromeric amyloid filaments in human brain revises our understanding of amyloid assembly and may be of significance for the pathogenesis of neurodegenerative diseases. |
External links | bioRxiv / PubMed:38979278 / PubMed Central |
Methods | EM (helical sym.) |
Resolution | 2.75 - 2.9 Å |
Structure data | EMDB-50621, PDB-9fof: EMDB-50628, PDB-9for: |
Source |
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Keywords | PROTEIN FIBRIL / TDP-43 / ANXA11 / amyloid / heteromeric amyloid / FTLD-TDP / neurodegeneration / dementia / brain / protein filament / FTLD-TDP Type C / neurodegenerative disease / filament |