Figure 7.

Role of Arg methylation in induction of endogenous genes important for the biogenesis and function of mitochondria. (A) SAOS2 cells in six-well plates were infected with adenoviruses expressing GFP, PGC-1α wild type, or PGC-1α R3K mutant (multiplicity of infection = 40) and harvested 24 h later. mRNA levels for the ERRα and cyt c genes were determined by quantitative PCR and normalized to the level of GAPDH mRNA. (B) SAOS2 cells in six-well plates were transfected with siRNA#1 against PRMT1 (100 pmol/well) two times, separated by 72 h. Four hours after the second siRNA transfection, cells were infected with adenovirus expressing GFP or PGC-1α and harvested 24 h later. mRNA levels for the indicated genes were determined by quantitative PCR and normalized to the GAPDH mRNA level. The mean and range of variation shown are from duplicate transfections in a single experiment that is representative of five independent experiments, each with duplicate transfected cell cultures. In all five experiments, the multiplicity of infection was 10-40, and the reduction in PRMT1 mRNA levels caused by siRNA was at least 50%. A paired, two-tailed t-test performed on the values from the five experiments indicated that the siRNA against PRMT1 caused significant decreases in the PGC-1α-induced levels of Cyt c mRNA (p = 0.014) and ERRα mRNA (p = 0.008). For the five experiments, the mean decrease and 95% confidence interval was 35 ± 15% for Cyt c mRNA, 26 ± 5% for ERRα mRNA, and 75 ± 9% for PRMT1 mRNA.