The dynamin-related GTPase, Dnm1p, controls mitochondrial morphology in yeast

• Published in: The Journal of cell biology 1998-10, Vol.143 (2), p.333-349
• Main Authors: Otsuga, D. (University of Utah, Salt Lake City, UT.), Keegan, B.R, Brisch, E, Thatcher, J.W, Hermann, G.J, Bleazard, W, Shaw, J.M
• Format: Article
• Language: English
• Subjects: ABSORCION; ABSORPTION; Actins - analysis; Antibodies; APARATO GOLGI; APPAREIL DE GOLGI; BINDING PROTEINS; BINDING SITES; CELL MEMBRANES; Cells; Cellular biology; Chromosome Mapping; CITOLOGIA; CYTOLOGIE; CYTOLOGY; DEFAUT; DEFECTOS; DEFECTS; DNA, Mitochondrial - analysis; DNM1 GENE; Dynamin I; Dynamins; ENDOCYTOSIS; Endocytosis - physiology; FENOTIPOS; Fungal Proteins - genetics; Fungal Proteins - metabolism; GENE; Gene Deletion; GENES; Genetic mutation; GOLGI APPARATUS; GTP Phosphohydrolases - genetics; GTP Phosphohydrolases - metabolism; GUANOSINE TRIPHOSPHATE; GUANOSINETRIPHOSPHATASE; HIDROLASAS; HYDROLASE; HYDROLASES; IMMUNOCYTOCHEMISTRY; IMMUNOLOGIE; IMMUNOLOGY; INDUCED MUTATION; INMUNOLOGIA; Kinetics; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Membranes; Microscopy, Electron; Microtubules - chemistry; Microtubules - metabolism; MITOCHONDRIA; Mitochondria - enzymology; Mitochondria - ultrastructure; Mitochondrial Proteins; MITOCHONDRIE; MITOCONDRIA; MUTACION INDUCIDA; Mutagenesis, Site-Directed - physiology; MUTANT; MUTANTES; MUTANTS; MUTATION PROVOQUEE; NUCLEOTIDE; NUCLEOTIDES; NUCLEOTIDOS; PHENOTYPE; PHENOTYPES; Plasmids; PROTEINAS AGLUTINANTES; PROTEINE DE LIAISON; Proteins; PYROPHOSPHATASES; Regular; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - chemistry; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae Proteins; Subcellular Fractions - chemistry; Subcellular Fractions - enzymology; Tubulin - analysis; VACUOLA; VACUOLE; VACUOLES; Vacuoles - ultrastructure; Yeasts
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.143.2.333

The Saccharomyces cerevisiae Dnm1 protein is structurally related to dynamin, a GTPase required for membrane scission during endocytosis. Here we show that Dnm1p is essential for the maintenance of mitochondrial morphology. Disruption of the DNM1 gene causes the wild-type network of tubular mitochondrial membranes to collapse to one side of the cell but does not affect the morphology or distribution of other cytoplasmic organelles. Dnm1 proteins containing point mutations in the predicted GTP-binding domain or completely lacking the GTP-binding domain fail to rescue mitochondrial morphology defects in a dnm1 mutant and induce dominant mitochondrial morphology defects in wild-type cells. Indirect immunofluorescence reveals that Dnm1p is distributed in punctate structures at the cell cortex that colocalize with the mitochondrial compartment. These Dnm1p-containing structures remain associated with the spherical mitochondria found in an mdm10 mutant strain. In addition, a portion of Dnm1p cofractionates with mitochondrial membranes during differential sedimentation and sucrose gradient fractionation of wild-type cells. Our results demonstrate that Dnm1p is required for the cortical distribution of the mitochondrial network in yeast, a novel function for a dynamin-related protein.