FIGURE 1.

Overexpression of PGC-1α or PGC-1β in C2C12 myotubes increases mitochondrial content and total protein content without altering protein synthetic rate. A, fully differentiated myotubes were infected at various times with adenoviruses expressing PGC-1α, PGC-1β, or GFP before all being collected at the same time after differentiation. Activity of citrate synthase, a mitochondrial enzyme, was determined spectrophotometrically from cell homogenates. *, p < 0.001 versus GFP. B, myotubes were infected with PGC-1α, PGC-1β, or GFP adenoviruses. Total protein per well of a 6-well plate was measured 48 h later. *, p < 0.001 versus GFP. C, protein synthetic rate was determined by measuring the incorporation of [³H]tyrosine for 2 h at the indicated times after adenoviral infection. No statistically significant differences were found.