The Slik kinase controls mitotic moesin function through regulation of its phosphorylation. (A) Relative levels of p-moesin (green) in prometaphase (arrowhead) and interphase cells. Error bars represent SD. ***, P < 0.005. (B and D) Distribution of total moesin or p-moesin during mitosis in control (B) or Slik-depleted cells (D). (C) Cells were immunolabeled to detect the Slik protein kinase, and DNA was counterstained with DAPI (blue). (E) Defects in cell shape and microtubule organization resulting from Slik depletion. α-Tubulin, green; F-actin, red; DNA, blue. Binucleated cells were observed in 5% of Slik-depleted cells (n = 500). (F) Time-lapse sequences of α-tubulin–GFP cells treated by Slik dsRNA. The red lines show maximal deviations of the spindle orientation from its initial position (green lines). Bars, 10 μm.