Figure 1.

Representative human FALS–SOD1 mutants expressed in sod1Δ yeast. (A) Homodimeric Cu, Zn SOD1 enzyme with FALS-associated point mutations shown in color, carboxyl–terminal truncations illustrated as strands, and the FALS–SOD1 point mutations characterized in yeast shown as space-filling atoms. (B-D) cDNAs encoding human wild-type SOD1 and FALS–SOD1 mutants were subcloned into yeast expression plasmids under the control of the PGK1 promoter (B), the yeast SOD1 promoter (C), or the methionine repressible promoter MET25 promoter (D). After transformation into sod1Δ yeast, each culture was grown to mid log phase, and 10 μg of each protein extract was electrophoresed on an SDS/PAGE gel and was stained with Coomassie blue (B-D, Middle) or was transferred to nitrocellulose and was immunoblotted with an SOD1 antibody (B-D, Bottom). The immunoblot in D is of the MET25 human wild-type SOD1 titration.