Figure 5.

Microtubule nucleation assay after neutralization of Hec1 and Hice1 by antibodies. (A) Representative images of radial microtubule arrays emanating from purified KE37 centrosomes. Centrosomes were incubated with 1, 2, or 3 μg of antibody for 30 min at 4°C before addition of rhodamine-conjugated tubulins. Normal mouse IgG was used as a negative control. (B) Quantification of average microtubule length from centrosomes (n = 50 centrosomes each, mixtures of interphase and mitotic centrosomes). Error bars indicate 1 SD. Bar, 20 μm. The effect among groups is significantly different (p < 0.02, two-way ANOVA test). (C) Quantification of average microtubule length from mitotic centrosomes isolated from KE37 cells (>90% of cells enriched at prometaphase). Error bars indicate 1 SD. Bar, 20 μm. The effect among groups is significantly different (p < 0.033, two-way ANOVA test). Similar results were also obtained from HeLa cells (data not shown).