Figure 6.

Restoration of E2F1-mediated apoptosis by Jab1, independent of deneddylating function. (A) REF52 cells already targeted for Jab1 shRNA degradation (shJab1-1) were stably infected with a nondegradable version of Jab1, or the nondegradable form with (H138A, H140A) amino acid substitution mutations that eliminates Jab1/CSN5 Nedd8 isopeptidase activity (mutant deneddylation). Extracts were analyzed by immunoblotting with anti-Jab1 and anti-actin antisera. (B) Cells described in A were brought to quiescence, infected with AdE2F1, and harvested for apoptosis assays at 40 h post-infection.