Motility of EEs in control cells and mutants of U. maydis. EEs were labeled by expressing GFP-Rab5a (Fuchs et al., 2006). In control cells (control), the organelles are constantly moving in a bidirectional fashion. Motility is blocked in EMD5 mutants (EMD5) but largely restored when an intact Hok1 protein is introduced into the mutant (EMD5 + Hok1). Deletion of hok1 abolishes endosome motility. Immobile clusters of endosomes concentrate at the cell pole, where the plus ends of the MTs are located (Schuster et al., 2011a). Cells were placed on an agar cushion, and image series were taken immediately using a charge-coupled device camera (CoolSNAP HQ2; Photometrics) and a laser-based inverted microscope (IX81 [Olympus] equipped with a VS-LMS4 Laser Merge System [Visitron Systems] and controlled by the software MetaMorph). Frames were taken every 150 ms for 29.9 s. Images were adjusted in brightness, contrast, and γ settings. Time in seconds and milliseconds; bar is in micrometers.
