Figure 5. Inhibition of proteasome mediated degradation in the Y79 cell line

Y79 cells were treated with DMSO (lanes 1-3) as carrier (Mock) or lactacystin (lanes 4-6) and 5-25 μl of extract was separated by SDS-PAGE. Lactacystin is a cell-permeable, irreversible inhibitor of the 20S and 26S Proteasome [63,64]. It works by targeting the catalytic β-subunit of the proteasome complex. Western analysis was performed with an anti-ubiquitin antibody. The amount of ubiquitin conjugated protein increased dramatically compared to Mock untreated cells as evidenced by a decrease of the free ubiquitin (arrow). A duplicate blot was probed with anti-PDE6 antibodies and no immunoreactivity was observed in the ubiquitin conjugated region of the blot (data not shown).