Ser_CDK phosphorylation contributes to dissociation of Drp1-x01 from MTs during mitosis. (A) GFP-Drp1-101 does not associate with the spindle apparatus in mitotic HeLa cells, but colocalizes with midbody MTs during cytokinesis (representative epifluorescence images of GFP and α-tubulin immunolabeling and Hoechst 33342 DNA staining). (B) Frames from a time-lapse video of a dividing HeLa cell expressing GFP-Drp1-001 and mitoRFP (see also Video 2). (C and D) Colocalization of endogenous Drp1 with α-tubulin and mitochondria (TOM20) in Jurkat cells is lost during mitosis. Representative epifluorescence images are shown in C, whereas Drp1-MT colocalization is quantified as the Pearson’s coefficient in D (means ± SEM [up]/SD [down] of 143 and 19 cells). (E and F) HeLa cells expressing the indicated GFP-Drp1 proteins were treated with vehicle or taxol (10 µM, 6 h), processed for immunofluorescence (representative images in C), and analyzed for colocalization of GFP-Drp1 and mitotic spindles (D; means ± SEM of 10–31 cells). Ø, P = 0.006; ⊗, P = 8 × 10⁻⁶; *, P = 3 × 10⁻²³.