Figure 1

TIA-1 secondary aggregation is impaired by TDP-43 depletion. (A-D) Cells where transfected with control or TDP-43 siRNA for 72 hr and subsequently treated with SA. (A) Representative images of SG in HeLa cells at 60 and 90 min. Scale bar, 10 μm. (B & C) Quantification of SG number and size by semi-automatic analysis using ImageJ at 60 and 90 min after SA treatment in (B) HeLa and (C) SK-N-SH cells. The means of 3 independent experiments ± SEM are plotted. * p<0.05. (D) siRNA transfected HeLa cells were treated with or without SA and collected 1 hr post-SA. Cytoplasmic extracts were digested with 0, 0.1, 0.2, 0.4, 0.8 or 1.6 mg/ml Proteinase K and assayed by immunoblot. TIA-1 is more protease-sensitive when TDP-43 is absent (arrows). Data is representative of 3 independent experiments. (E) Quantification of remaining TIA-1 protein following treatment with 0. 8 mg/ml Proteinase K, expressed relative to untreated samples.