Fig. 4. Effects of apoptotic agents on the centrosomal SAS-6 and pericentrin.

a HeLa cells were treated with thymidine and transferred into a medium with MG132. Ten hours later, the cell lysates were fractionated with sucrose-gradient ultracentrifugation and subjected to immunoblot analyses with antibodies specific to γ-tubulin, PARP-1, and SAS-6. b The G2 phase HeLa cells were treated with MG132 for 8 h and coimmunostained with antibodies specific to SAS-6 (green) and pericentrin (red). DNA was visualized with DAPI (blue). Scale bar, 10 μm. The centriolar intensity of SAS-6 and centrosomal area of pericentrin were measured and presented with box and whisker plots. c HeLa cells were treated with etoposide, staurosporine, or paclitaxel for 24 h and immunostained with the pericentrin antibody. Greater than 100 centrosomes per experimental group were analyzed in two independent experiments. *P < 0.05