Mitochondrial movement and morphology depend on an intact actin cytoskeleton in Aspergillus nidulans.
Mitochondria are essential organelles for the oxidative energy metabolism in eukaryotic cells. Determinants of mitochondrial morphology as well as the machinery underlying their subcellular distribution are not well understood. In this study we constructed an Aspergillus nidulans strain, in which mitochondria are stained with the green-fluorescent protein (GFP) to visualize them and study their behavior in vivo (http://www.uni-marburg. de/mpi/movies/mitochondria/mitochondria.html). Mitochondria form a complex membranous system in the cytoplasm consisting of interconnected tubular structures. Mitochondrial tubes separate frequently or produce small organelles that migrate some distance with velocities of up to 15 microm/min before they fuse again with the reticulum. Experiments using cytochalasin A as an anti-cytoskeletal drug revealed that a functional actin cytoskeleton is crucial for mitochondrial morphology and the dynamic behavior of the mitochondrial network. Movement of organelles along actin filaments requires actin-dependent motor proteins, such as myosin. We found that MyoA, a class I myosin motor of A. nidulans involved in vesicle migration, is not responsible for mitochondrial movement.
Suelmann
R
R
Laboratorium für Mikrobiologie, Philipps-Universität Marburg and Max-Planck-Institut für terrestrische Mikrobiologie, Marburg, Germany.
Fischer
R
R
D000199:Actins / Q000502:physiology*; D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D001542:Benomyl / Q000494:pharmacology; D001692:Biological Transport; D003572:Cytochalasins / Q000494:pharmacology; D003599:Cytoskeleton / Q000502:physiology*; D005656:Fungal Proteins / Q000502:physiology; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology; D024461:Myosin Type I; D009218:Myosins / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013172:Spores, Fungal / Q000235:genetics / Q000502:physiology
D000199:Actins; D003572:Cytochalasins; D005656:Fungal Proteins; D008164:Luminescent Proteins; C092129:MyoA protein, Aspergillus nidulans; D011993:Recombinant Fusion Proteins; C031218:cytochalasin A; D049452:Green Fluorescent Proteins; D024461:Myosin Type I; D009218:Myosins; D001542:Benomyl