Figure 6.

Sesn2 controls XIAP expression via regulation of protein stability. (A, B) XIAP protein is stabilized in Sesn2-silenced cells. (A) ³⁵S pulse-chase labeling experiment demonstrated significant effect of Sesn2 knockdown on the stability of XIAP protein. Sesn2-silenced or control H460 cells were incubated with ³⁵S protein labeling mix for 1 hr followed by incubation with non-radioactive medium for different time intervals. At each time-point the cells were lyzed and XIAP protein was immunoprecipitated with anti-XIAP antibody (anti-GFP antibodies were used as a negative control) and analyzed by SDS-PAGE followed by autoradiography, On the lower panel, the whole cell lysates (WCL) were analyzed by SDS-PAGE electrophoresis. (B) Quantification of the radioactively-labeled proteins in Sesn2-silenced and control cells. Cells were treated as in A and the amount of labeled Sesn2 protein and its half-life were analyzed on a phosphoimager with ImageQuant software.