Templated Aggregation of TAR DNA-binding Protein of 43 kDa (TDP-43) by Seeding with TDP-43 Peptide Fibrils
Year: 2016
Type: article
Abstract: TAR DNA-binding protein of 43 kDa (TDP-43) has been identified as the major component of ubiquitin-positive neuronal and glial inclusions in frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Aggregation of TDP-43 to amyloid-like fibrils and spreading of the aggregates are suggested to account for the pathogenesis and progression of these diseases. To investigate the molecular mechanisms of TDP-43 aggregation, we attempted to identify the amino acid sequence required for the aggregation. By expressing a series of deletion mutants lacking 20 amino acid residues in the C-terminal region in SH-SY5Y cells, we established that residues 274–313 in the glycine-rich region are essential for aggregation. In vitro aggregation experiments using synthetic peptides of 40 amino acids from this sequence and adjacent regions showed that peptides 274–313 and 314–353 formed amyloid-like fibrils. Transduction of these fibrils induced seed-dependent aggregation of TDP-43 in cells expressing wild-type TDP-43 or TDP-43 lacking nuclear localization signal. These cells showed different phosphorylated C-terminal fragments of TDP-43 and different trypsin-resistant bands. These results suggest that residues 274–353 are responsible for the conversion of TDP-43 to amyloid-like fibrils and that templated aggregation of TDP-43 by seeding with different peptides induces various types of TDP-43 pathologies, i.e. the peptides appear to act like prion strains. TAR DNA-binding protein of 43 kDa (TDP-43) has been identified as the major component of ubiquitin-positive neuronal and glial inclusions in frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Aggregation of TDP-43 to amyloid-like fibrils and spreading of the aggregates are suggested to account for the pathogenesis and progression of these diseases. To investigate the molecular mechanisms of TDP-43 aggregation, we attempted to identify the amino acid sequence required for the aggregation. By expressing a series of deletion mutants lacking 20 amino acid residues in the C-terminal region in SH-SY5Y cells, we established that residues 274–313 in the glycine-rich region are essential for aggregation. In vitro aggregation experiments using synthetic peptides of 40 amino acids from this sequence and adjacent regions showed that peptides 274–313 and 314–353 formed amyloid-like fibrils. Transduction of these fibrils induced seed-dependent aggregation of TDP-43 in cells expressing wild-type TDP-43 or TDP-43 lacking nuclear localization signal. These cells showed different phosphorylated C-terminal fragments of TDP-43 and different trypsin-resistant bands. These results suggest that residues 274–353 are responsible for the conversion of TDP-43 to amyloid-like fibrils and that templated aggregation of TDP-43 by seeding with different peptides induces various types of TDP-43 pathologies, i.e. the peptides appear to act like prion strains.
Source: Journal of Biological Chemistry
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2341346355