Figure 7

The introduction of experimental mutations that monomerize WT-SOD1 produce varied effects on interactions with mutant SOD1. A) Immunoblots of detergent-insoluble (P2) and soluble (S1) fractions of HEK293FT cells transfected with mouse and/or human SOD1 constructs for 24 (left panels) or 48 (right panels) hours. Blots were probed with an antibody that recognizes both mouse and human SOD1 proteins. Asterisk denotes probing with an antibody that is specific against human SOD1 protein. B) Quantification of the relative aggregation propensity, as described in Figure 1, for cells transfected for 24 (black bars) or 48 (white bars) hours. Statistical analyses was performed to establish whether the measured amount of insoluble mutant SOD1 in cells expressing only G85R-hSOD1, or only G86R-mSod1, differed from the amount that became insoluble when either was co-expressed with monomerized variants of mSod1 and hSOD1. Explanations for notations on the graph are as follows. The levels of insoluble G85R-hSOD1 in cells expressing only the mutant SOD1 were significantly (p ≤ 0.05) higher than in cells co-transfected with WT-hSOD1mon (hWTmon) at 24 hrs (a) and 48 hrs (b) or WT-mSod1mon (mWTmon) at 48 hrs (b). The level of G86R-mSod1 in cells expressing only mutant SOD1 were significantly (p ≤ 0.05) higher than in cells co-transfected with WT-hSOD1mon or WT-mSod1mon at 24 hrs (c) or WT-hSOD1 at 48 hrs (d). Bars represent mean ± SEM.