Figure 6.

Mutation of the PY motif of Mdm34 does not affect ER or mitochondrial morphology, mitochondrial fission or Mdm34 localization. (A) WT or mdm34[3PA] strains bearing GFP-HDEL (ER marker) and Mito-mCherry expressed from vectors integrated into the chromosome were grown to early exponential growth phase in YPD at 30°C. Mitochondrial DNA was stained by adding 1 µg/mL DAPI to the growth medium and incubating for a further 2 to 3 h. Cells were washed twice and processed for fluorescence microscopy. (B) The same cells as in (A) were either left untreated (No treatment) or incubated with 50 µg/mL α factor for 3 h or with 2 mM H₂O₂ for 2 h. The cells were then washed twice and processed for fluorescence microscopy. (C) MDM34-GFP and mdm34[3PA]-GFP strains transformed with pYX142-mt-RFP were grown in YPD at 30°C before microscopy. Arrows indicate GFP at mitochondrial fission sites and arrowheads indicate GFP at mitochondrial tips. Cell shape was assessed with DIC.