Figure 5. Expression of K6W-ubiquitin, proteasome inhibition, and heat shock increase the Hsp70 protein in human lens epithelial cells. Lens epithelial cells were infected with the adenovirus encoding K6W-ubiquitin or the control adenovirus for 48 h, treated with or without MG132 for 6 h, or incubated at 45 °C for 1 h and recovered at 37 °C for 1 h. Total proteins were collected in a SDS-loading buffer. Levels of Hsp70, Hsp90, Grp75, and Grp78 were determined by western blotting using respective antibodies. The levels of β-actin were also determined by western blotting and used as a protein loading control.