Figure 7.

The human Aurora kinase complex functionally and physically interacts with hSgo1. (A) A chromatin extract of nocodazole-arrested mitotic HeLa cells was immunoprecipitated with anti-hSgo1 or control IgG. The extracts (input) and the immunoprecipitates (IP) were analyzed by Western blotting using antibodies against the indicated proteins. (B) HeLa cells were mock-transfected or transfected with siRNAs against Aurora B or Survivin, and stained with anti-hSgo1, anti-Aurora B, and ACA. DNA was counterstained with Hoechst 33342. Bar, 10 μm. Quantification of centromeric signals of hSgo1 is shown on the right. For each cell, the fluorescent intensities of hSgo1 at 10 centromeres were related to the intensities of the corresponding ACA signals. Error bars show the SEM (10 cells for each). (C) Mitotic cells after RNAi treatment were harvested by mitotic shake-off and then treated with nocodazole for 4 h. The prometaphase-arrested cells were spun on slides and stained with ACA and Hoechst 33342. Magnifications of representative ACA pairs are shown. Bar, 10 μm. The average distance between paired ACA signals is shown on the right. One dot represents the average distance of at least 20 pairs within a single cell. Ten cells were examined.