Figure 6

Mutation of the methylation site attenuates the effect of HuR in regulating mRNA turnover and cell senescence. (A) Human diploid fibroblasts were stably transfected with a vector expressing flag-HuR (W) or flag-HuRΔ (M), or an empty vector (−). Western blot analysis was performed to assess the protein levels of HuR, cyclin A, cyclin B1, c-fos, SIRT1, p16, and GAPDH, and quantified by densitometry. (B,C) Cells described in Figure 6A were subjected to FACS analysis (B) and SA-β-gal staining (C) to analyze the cell cycle distribution and cell senescent status, as described in Figure 5B and 5C. Values of the SA-β-gal staining represent means ± SDs of the results from three independent experiments. Statistical significance was analyzed by Student’s t test.