FIG. 6.
Sumoylated PEA3 is unstable. (A) 293 cells were cotransfected with PEA3, Ubc9, or His-tagged SUMO-2. Cells were treated with PMA for 3 h, and then cycloheximide (CHX) was added and cells harvested at the indicated times after cycloheximide addition. Sumoylation of PEA3 was probed as described for Fig. 1C. Bulk PEA3 levels were determined by harvesting in the absence of NEM (middle panel). GAPDH levels were probed as a loading control (bottom panel). (B) Graphical representation of the data from panel A. (C) 293 cells were transfected as described for panel A, but MG132 was added at the same time as PMA in lanes 4 to 6. PD, results from pulldown assay; IB, immunoblotting results.