Figure 3

Tpk3p dependent ROS production and mitochondrial dysfunction. ROS production and aberrant mitochondrial morphology are a result of Tpk3p activity. We examined the effect on ROS production on diauxic shift cultures with and without high Tpk3p activity. Strains were grown in the presence of 4 mM cAMP for 24 hours in MM supplemented with H₂DCF-DA. Cells were then either examined by fluorescence microscopy or flow cytometry for the presence of ROS, fluorescing cells that indicate the presence of ROS are found in the M2 region of the histograms presented (A). Mitochondrial morphology was investigated by expression of a targeted GFP molecule (B). Routine respiration was assessed in wild type and Δpde2Δtpk3 cells overexpressing an active TPK3 or a kinase dead version (TPK3^KD) of the enzyme in the presence and absence of exogenous 4 mM cAMP (C). Mitochondrial morphology was also assessed in Δpde2Δtpk3 cells overexpressing TPK3 or TPK3^KD in the presence and absence of exogenous 4 mM cAMP (D). Scale Bar = 10 μM.