FIGURE 5.

Overexpression of Cdc25A correlates with earlier phosphorylation of APC3 on Thr²⁴⁴. A, U2OS Cdc25A cells were released from a double thymidine block (left), and samples for WB were collected at the indicated time points (hours) and probed with the respective antibodies. Note the earlier appearance of the APC3-Thr(P)²⁴⁴ signal in induced cells. B, induced and non-induced U2OS Cdc25A cells were fixed on coverslips 9 h after release from a double thymidine block (left). Cells were stained with anti-cyclin B (green) and anti-APC3-Thr(P)²⁴⁴ (red) antibodies. DNA was stained with Hoechst (blue). Scale bar, 10 μm. The arrows indicate the Thr(P)²⁴⁴ signal decorating the centrosomes. Right, the percentage of cells with a positive centrosomal Thr(P)²⁴⁴ signal for Cdc25A induced and non-induced cells. Error bars, S.D. in three independent experiments (n = 200).