Depletion of endogenous dyn2 by RNAi results in stable microtubule accumulation. HeLa cells were transfected with control or dyn2-specific siRNA. (A) Immunofluorescence of RNAi-treated cells. The cells were fixed and visualized with antibodies specific for α-tubulin, acetylated tubulin (Acet-tubulin), EB1, and pericentrin. (B) Western blot analysis of the cells transfected with control or dyn2 siRNA. The blots were visualized with the indicated antibodies. (C and D) Dyn2 siRNA–treated cells are resistant to nocodazole treatment. The cells were incubated with nocodazole for 30 or 60 min and then fixed and visualized with anti–α-tubulin. The images in C show the cells after 30 min of nocodazole treatment. In D, the cells with intact microtubules are expressed relative to the total number of cells. The results represent the mean ± SD from two independent experiments. (E) The microtubules are less dynamic in dyn2 siRNA–treated cells. HeLa cells stably expressing GFP-tubulin were transfected with control or dyn2 siRNA, and images were collected every 2 s. Representative microtubules are indicated by arrows. Bars: (A and C) 10 µm; (E) 2 µm.