Proteomic Analysis of Heavy Metal-Induced Toxicity Using the Cellular Slime Mould Dictyostelium discoideum: Effects of Copper Exposure on Aggregation and Protein Expression

The cellular slime mould <i>Dictyostelium discoideum</i> is a soil-dwelling eukaryotic organism that undergoes distinctive morphological changes during starvation, making it a promising candidate for bioassay development. In this study, we evaluated the effects of copper (Cu) exposure on the morphological transformation of <i>D. discoideum</i> and performed a comparative proteomic analysis. Copper exposure on agar media delayed aggregate formation by 3.5 h compared to the controls. Approximately 280 protein spots were detected using immobilised pH gradient two-dimensional gel electrophoresis followed by silver staining. Three spots disappeared upon exposure to Cu. Based on isoelectric point and molecular weight analyses, the proteins were predicted to be formin-1, a cytoplasmic regulator of adenylyl cyclase (CRAC), and a tetratricopeptide repeat (TPR)-containing protein. Formin-1 and CRAC are involved in aggregation processes. These findings suggest that Cu disrupts aggregation-related protein expression in <i>D. discoideum</i> and highlight the potential of <i>D. discoideum</i>-based bioassays using proteomic biomarkers for environmental monitoring.