Figure 1 Comparison of two-dimensional (2D) differential gel electrophoresis patterns of differentially expressed modified proteins. (a,b) Wild-type and Δyca1 mutant cells treated without (a) or with (b) 0.5 mM H2O2. Wild-type and Δyca1 mutant cell extracts were labeled with Cy3 and Cy5 fluorescent dyes, respectively, mixed together and separated on 2D gels. Circled spots signify posttranslational modifications of proteins, which give rise to more diffuse isoelectric focusing points and molecular weights. Spots with yellow color refer to unmodified proteins. Green dots on the image are reference markers. H2O2, hydrogen peroxide; WT, wild type.