Research Paper Volume 1, Issue 1 pp 131—145

Extension of chronological life span by reduced TOR signaling requires down-regulation of Sch9p and involves increased mitochondrial OXPHOS complex density

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Figure 2. Reduced TOR signaling increases the number of mitochondrial OXPHOS complexes per organelle, as opposed to the number of mitochondria/cell. Comparative analysis of four mitochondria-related parameters in wild-type (wt) and tor1Δ strains is shown. (A) Western blot analysis of four OXPHOS subunits (Cox1p-4p) and porin (as a mitochondrial normalization control). Fifty μg of mitochondrial extract was loaded in each lane. The fold difference between wt and tor1Δ normalized to the porin signal is shown on the right. (B) Mitochondrial mass as estimated by the amount of mitochondrial-GFP signal determined by FACS (see Materials and Methods). (C) mtDNA copy number determined by real-time PCR (measured as the ratio of the mitochondrial gene target COX1 relative to the nuclear gene target ACT1). (D) Mitochondrial membrane potential determined by DiOC6 staining and FACS analysis. In B-D means of at least three biological replicates +/- one standard deviation are graphed (** represents a p-value from a student t-test that is <0.01).