Figure 3.

The ability of VN8 modules to signal proteolysis correlates with their ability to activate transcription. (A) Steady-state levels of the GAL4-VN8 activators. Human HeLa cells were transiently transfected with expression constructs encoding the indicated GAL4-fusion proteins. After transfection, cells were either untreated (−LLnL) or treated with the proteasome inhibitor LLnL (+LLnL). Total proteins were prepared and HA-tagged GAL4-fusion proteins revealed by SDS/PAGE and immunoblotting analysis. (B) Stability of GAL4–VN8 activators. GAL4-VN8 proteins were transiently expressed in HeLa cells and their stabilities were determined by pulse–chase analysis as described in Materials and Methods.