FIGURE 5.

The C-terminal region of p11 contains a polyubiquitination and degradation determinant. A, schematic representation of FLAG-tagged p11 C-terminal truncation plasmids. B, FLAG-tagged C-terminal truncation mutants of p11 were cotransfected with A2-myc into HEK 293 cells. Whole cell extracts were either immunoprecipitated (IP) with anti-Myc and blotted with anti-FLAG IgG (upper panel) or immunoblotted (WB) with anti-Myc or anti-FLAG IgG (lower panels). C, lysates from cells cotransfected with FLAG-tagged p11 truncation mutants and HA-ubiquitin (HA-Ub) were immunoprecipitated with anti-HA and blotted with anti-FLAG IgG. D, HEK 293 cells, transfected with p11 truncation mutants, were treated with cycloheximide at 48 h after transfection (CHX, 10 μg/ml) for the indicated time periods. Cell lysates were immunoblotted with anti-FLAG (left panels) or anti-GAPDH (right panels).