title: Analysis of ER-mitochondria contacts using correlative fluorescence microscopy and soft X-ray tomography of mammalian cells.
abstract: Mitochondrial fission is important for organelle transport, quality control and apoptosis. Changes to the fission process can result in a wide variety of neurological diseases. In mammals, mitochondrial fission is executed by the GTPase dynamin-related protein 1 (Drp1; encoded by DNM1L), which oligomerizes around mitochondria and constricts the organelle. The mitochondrial outer membrane proteins Mff, MiD49 (encoded by MIEF2) and MiD51 (encoded by MIEF1) are involved in mitochondrial fission by recruiting Drp1 from the cytosol to the organelle surface. In addition, endoplasmic reticulum (ER) tubules have been shown to wrap around and constrict mitochondria before a fission event. Up to now, the presence of MiD49 and MiD51 at ER-mitochondrial division foci has not been established. Here, we combine confocal live-cell imaging with correlative cryogenic fluorescence microscopy and soft x-ray tomography to link MiD49 and MiD51 to the involvement of the ER in mitochondrial fission. We gain further insight into this complex process and characterize the 3D structure of ER-mitochondria contact sites.
authors.affiliation: Hudson Institute for Medical Research, Monash Micro Imaging, Monash University, Melbourne 3168, Australia.
authors.forename: Kirstin D
authors.initials: KD
authors.lastname: Elgass
authors.affiliation: Department of Anatomy, School of Medicine, University of California San Francisco, San Francisco, CA 94158, USA National Centre for X-ray Tomography, Advanced Light Source, Berkeley, CA 94720, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Smith
authors.affiliation: Department of Anatomy, School of Medicine, University of California San Francisco, San Francisco, CA 94158, USA National Centre for X-ray Tomography, Advanced Light Source, Berkeley, CA 94720, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: LeGros
authors.affiliation: Department of Anatomy, School of Medicine, University of California San Francisco, San Francisco, CA 94158, USA National Centre for X-ray Tomography, Advanced Light Source, Berkeley, CA 94720, USA Carolyn.Larabell@ucsf.edu Michael.Ryan@monash.edu.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Larabell
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Melbourne 3800, Australia Carolyn.Larabell@ucsf.edu Michael.Ryan@monash.edu.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Ryan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D034281:Dynamins; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D021621:Imaging, Three-Dimensional; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism*; D063154:Mitochondrial Dynamics / Q000502:physiology*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D014057:Tomography, X-Ray Computed
chemical_list: C000608253:MIEF2 protein, mouse; D008565:Membrane Proteins; C000597830:MiD51 protein, mouse; D024101:Mitochondrial Proteins; D018160:Receptors, Cytoplasmic and Nuclear; C486391:Dnm1l protein, mouse; D034281:Dynamins
keywords: Confocal microscopy; Correlative imaging; Endoplasmic reticulum; Microscopy imaging; Mitochondria; Mitochondrial fission; Soft X-ray tomography