Tom70-GFP-IAA7 is protected within MDCs from the auxin-degron system. (A) Immunoblots of whole-cell protein extracts from yeast expressing Tom70-yEGFP-IAA7 and probed for the indicated mitochondrial proteins or GFP. Extracts were obtained at the indicated time points after treatment with either 1 mM auxin or an equivalent volume of 70% ethanol (vehicle). (B) Max projections of widefield fluorescence microscopy images of yeast cells expressing Tom70-GFP-IAA7 and Tom70-mCherry. Images were taken 1.5 h after treatment with either 1 mM auxin (Veh + Aux) or an equivalent volume of 70% ethanol (Veh + Veh), which were both added 2 h after treatment with DMSO. Scale bar = 2 µm. (C) Similar analysis as shown in B except yeast cells were treated with 200 nM Rap 2 h prior to treatment with either auxin (Rap + Aux) or an equivalent volume of 70% ethanol (Rap + Veh). Yellow arrows indicate mitochondrial tubule, white arrows indicate MDCs. *Panels showing an increased pixel intensity. Scale bar = 2 µm. (D) Immunoblot of whole-cell protein extracts from yeast expressing Tom70-GFP-IAA7. Extracts were obtained at the indicated time points around treatment with 1 mM auxin. Auxin treatment occurred 2 h after treatment with either 200 nM Rap or DMSO (Vehicle) and a whole-cell protein extract sample was obtained prior to drug treatment (−2). Pgk1 is provided as a loading control. The graph on the right shows the quantification of the percent Tom70-GFP-IAA7 remaining after auxin treatment normalized to the Pgk1 loading control; error bars show mean ± SD of three independent experiments. (E) An analysis comparing the fluorescence intensities elicited by either Tom70-mCherry or Tom70-GFP-IAA7 within the mitochondrial tubule at the indicated time points. Fluorescence intensity is shown as a ratio of emissions from mitochondrial tubules of auxin-treated cells/vehicle-treated cells. (F) A similar analysis as shown in E except the fluorescence intensity ratios were derived from comparing emissions from MDCs of auxin-treated cells/vehicle-treated cells. Source data are available for this figure: SourceData F5.