Figure 6. Loss and overexpression of TRAP1 activates the UPR^mt pathway.

(A – C) Anti-Dve antibody (green) reveals tight cytosolic localization of Dve in neuronal cell bodies in brains of adult w¹¹¹⁸; +/+; +/+ males. Nuclear dye DAPI (red) stains the entire nucleus although it appears brighter in the nucleolus. The merged image of anti-Dve and DAPI stain reveals crisp cytosolic sub-cellular localization of Dve. (D – F) Dve staining appears diffuse in neuronal cell bodies of male w; TRAP1A4/TRAP1A4, +/+ flies and exhibits considerable overlap with the nucleus. (G – I) Dve staining appears similarly diffused and overlaps with nuclear stain in neuronal cell bodies of male w; +/+; UAS-TRAP1^4M/ActinGal4 flies. Scale bar equals 3.5 µm. (J) Ratio of staining intensity of Dve in the cytoplasm relative to the nucleus in indicated genotypes. (K) mRNA expression of Dve in w¹¹¹⁸; +/+; +/+ females is not significantly different from mutant (p=0.2) and overexpression (p=0.9) strains. (L, M and N) Male w; TRAP1Δ4/TRAP1Δ4, +/+ and w; +/+; UAS-TRAP1^7M/ActinGal4 flies exhibit significantly increased mRNA expression of Hsp60, mtHsp70 and CG5045 as compared to w¹¹¹⁸; +/+; +/+. (O, P and Q) Female w; TRAP1A4/TRAP1A4; +/+ exhibit significantly increased mRNA expression of Hsp60 as compared to w¹¹¹⁸; +/+; +/+, but not that of mtHsp70 and CG5045. In all cases, data are presented as fold change from control. Error bars denote standard error of means; statistical significance was determined using one-way ANOVA. (*) indicates p < 0.05, (**) indicates p < 0.001.