Fig. 10. (A) p21 is overexpressed in mtDNA-depleted L929 cells. Western blotting analysis for p53 and p21 derived from L929 and mtDNA-depleted L929 cells. (B) p21 expression is stimulated in L929 cells treated with 10 µM forskolin for 16 h (lanes 1 and 2) while its expression is reduced in mtDNA-depleted cells transiently transfected with M1-CREB or incubated with 50 µM KN-93 for 16 h (lanes 3–5). Protein loading was controlled by the expression of histone H1.