Mitochondrial fusion intermediates revealed in vitro.
The events that occur during the fusion of double-membraned mitochondria are unknown. As an essential step toward determining the mechanism of mitochondrial fusion, we have captured this event in vitro. Mitochondrial outer and inner membrane fusion events were separable and mechanistically distinct, but both required guanosine 5'-triphosphate hydrolysis. Homotypic trans interactions of the ancient outer transmembrane guanosine triphosphatase, Fzo1, were required to promote the fusion of mitochondrial outer membranes, whereas electrical potential was also required for fusion of inner membranes. Our conclusions provide fundamental insights into the molecular events driving mitochondrial fusion and advance our understanding of the evolution of mitochondrial fusion in eukaryotic cells.
Section of Molecular and Cellular Biology, Center of Genetics and Development, University of California, Davis, CA 95616, USA.
Shelly
S
Meeusen
J Michael
JM
McCaffery
Jodi
J
Nunnari
D000255:Adenosine Triphosphate / Q000378:metabolism; D004734:Energy Metabolism; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006160:Guanosine Triphosphate / Q000378:metabolism; D007425:Intracellular Membranes / Q000502:physiology* / Q000648:ultrastructure; D008164:Luminescent Proteins / Q000378:metabolism; D008561:Membrane Fusion; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000502:physiology* / Q000648:ultrastructure*; D024101:Mitochondrial Proteins; D008954:Models, Biological; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D000097573:Red Fluorescent Protein
D000255:Adenosine Triphosphate; D020558:GTP Phosphohydrolases; D049452:Green Fluorescent Proteins; D006160:Guanosine Triphosphate; D008164:Luminescent Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097573:Red Fluorescent Protein; C401395:FZO1 protein, S cerevisiae