Figure 2.

TDP-43 is cleaved by viral protease 3C. (a and b) Cleavage of TDP-43 by viral protease 3C. (a) HeLa cell lysates (50 μg) were incubated with or without viral protease 3C (0.1 μg) for different times as indicated. (b) Protein extracts from HeLa cells transiently expressing HA-TDP-43-GFP were incubated with wild-type or catalytically inactive mutant of 3C (3C^mut) for 16 h. In vitro cleavage assay was performed as described in the ‘Materials and Methods'. Expression of TDP-43 was examined using an anti-N-terminal TDP-43 (a) or anti-HA antibody (b). (c–e) Effects of general caspase inhibition on CVB3-mediated TDP-43 cleavage. HeLa cells were infected with CVB3 for 7 h (c) or 9 h (e) in the presence or absence of Z-VAD-FMK (zVAD, 50 μM). Western blotting was performed to examine the expression of TDP-43 using an anti-N-terminal TDP-43 antibody and the cleavage of caspase-3 by an anti-caspase-3 antibody (d). VP1 and β-actin was detected as described above. * indicates a cleaved TDP-43 band at ~35 kDa. ‘-‘, vehicle control (treated with DMSO). Densitometric analysis was carried out as in Figure 1