Figure 2. Oxidative stress results in an accumulation of ubiquitin conjugates.
(A) ARPE-19 cells were exposed to 10 or 50 μM H2O2 for 4 hours and levels of endogenous ubiquitin conjugates were determined by Western blotting. (B) ARPE-19 cells were treated with blue light alone, A2E alone, or both A2E and blue light as described. Levels of endogenous ubiquitin conjugates were determined by Western blotting. Levels of β-actin were used as protein loading controls.