Structural Evidence of Amyloid Fibril Formation in the Putative Aggregation Domain of TDP-43.
TDP-43 can form pathological proteinaceous aggregates linked to ALS and FTLD. Within the putative aggregation domain, engineered repeats of residues 341-366 can recruit endogenous TDP-43 into aggregates inside cells; however, the nature of these aggregates is a debatable issue. Recently, we showed that a coil to β-hairpin transition in a short peptide corresponding to TDP-43 residues 341-357 enables oligomerization. Here we provide definitive structural evidence for amyloid formation upon extensive characterization of TDP-43(341-357) via chromophore and antibody binding, electron microscopy (EM), solid-state NMR, and X-ray diffraction. On the basis of these findings, structural models for TDP-43(341-357) oligomers were constructed, refined, verified, and analyzed using docking, molecular dynamics, and semiempirical quantum mechanics methods. Interestingly, TDP-43(341-357) β-hairpins assemble into a novel parallel β-turn configuration showing cross-β spine, cooperative H-bonding, and tight side-chain packing. These results expand the amyloid foldome and could guide the development of future therapeutics to prevent this structural conversion.
†Instituto de Química Física Rocasolano, CSIC Serrano 119, 28006 Madrid, Spain.
Miguel
M
Mompeán
‡Instituto Cajal, CSIC Avda, Doctor Arce 37, E-28002 Madrid, Spain.|§Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Crta. de Cantoblanco no. 8, E-28049 Cantoblanco, Madrid, Spain.
Rubén
R
Hervás
∥Department of Chemistry, Columbia University, 344 Havemeyer Hall, New York, New York 10027, United States.
Yunyao
Y
Xu
⊥Department of Biological Sciences, Columbia University, New York, New York 10027, United States.
Timothy H
TH
Tran
#International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34149 Trieste, Italy.
Corrado
C
Guarnaccia
#International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34149 Trieste, Italy.
Emanuele
E
Buratti
#International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34149 Trieste, Italy.
Francisco
F
Baralle
⊥Department of Biological Sciences, Columbia University, New York, New York 10027, United States.
Liang
L
Tong
‡Instituto Cajal, CSIC Avda, Doctor Arce 37, E-28002 Madrid, Spain.|§Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Crta. de Cantoblanco no. 8, E-28049 Cantoblanco, Madrid, Spain.
Mariano
M
Carrión-Vázquez
∥Department of Chemistry, Columbia University, 344 Havemeyer Hall, New York, New York 10027, United States.
Ann E
AE
McDermott
†Instituto de Química Física Rocasolano, CSIC Serrano 119, 28006 Madrid, Spain.
Douglas V
DV
Laurents
D000682:Amyloid / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D010446:Peptide Fragments / Q000737:chemistry*
D000682:Amyloid; D004268:DNA-Binding Proteins; D010446:Peptide Fragments
X-ray diffraction; amyloid; amyotrophic lateral schlerosis; cross-beta spine; molecular dynamics