title: Cytoskeletal-assisted dynamics of the mitochondrial reticulum in living cells.
abstract: Subcellular organelle dynamics are strongly influenced by interactions with cytoskeletal filaments and their associated motor proteins, and lead to complex multiexponential relaxations that occur over a wide range of spatial and temporal scales. Here we report spatio-temporal measurements of the fluctuations of the mitochondrial reticulum in osteosarcoma cells by using Fourier imaging correlation spectroscopy, over time and distance scales of 10(-2) to 10(3) s and 0.5-2.5 microm. We show that the method allows a more complete description of mitochondrial dynamics, through the time- and length-scale-dependent collective diffusion coefficient D(k,tau), than available by other means. Addition of either nocodazole to disrupt microtubules or cytochalasin D to disassemble microfilaments simplifies the intermediate scattering function. When both drugs are used, the reticulum morphology of mitochondria is retained even though the cytoskeletal elements have been de-polymerized. The dynamics of the organelle are then primarily diffusive and can be modeled as a collection of friction points interconnected by elastic springs. This study quantitatively characterizes organelle dynamics in terms of collective cytoskeletal interactions in living cells.
authors.affiliation: Department of Chemistry and Materials Science Institute, University of Oregon, Eugene 97403, USA.
authors.forename: Michelle K
authors.initials: MK
authors.lastname: Knowles
authors.forename: Marina G
authors.initials: MG
authors.lastname: Guenza
authors.forename: Roderick A
authors.initials: RA
authors.lastname: Capaldi
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Marcus
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D001859:Bone Neoplasms; D003571:Cytochalasin B / Q000494:pharmacology; D003599:Cytoskeleton / Q000648:ultrastructure*; D005583:Fourier Analysis; D006801:Humans; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure; D008928:Mitochondria / Q000648:ultrastructure*; D015739:Nocodazole / Q000494:pharmacology; D012516:Osteosarcoma; D014407:Tumor Cells, Cultured
chemical_list: D003571:Cytochalasin B; D015739:Nocodazole