Endogenous Drp1-x01 copurifies and colocalizes with MTs. (A) PC12 cells stably expressing GFP-tagged Drp1-100, -101, and -111 were lysed ± taxol (10 µM) and lysates were subjected to centrifugation through a 1-M sucrose cushion. (B) Similar experiments with Jurkat cells and acutely dissociated rat thymocytes show copurification of endogenous Drp1 with MTs. About 5% of the lysate and 10% of the pellets was loaded. Total protein was visualized by staining blots with Ponceau S before antibody incubation. (C and D) Jurkat cells treated ± nocodazole (100 ng/ml, 2 h) were immunolabeled for mitochondria (TOM20), Drp1, and α-tubulin and imaged by confocal microscopy (C; representative images). MT depolymerization decreases colocalization of endogenous Drp1 with α-tubulin, but increases colocalization with mitochondria (D; means ± SEM of 49 and 23 cells). *, P < 10⁻⁶.