title: Nucleic acid import into mitochondria: New insights into the translocation pathways.
abstract: Mitochondria have retained indispensable but limited genetic information and they import both proteins and nucleic acids from the cytosol. RNA import is essential for gene expression and regulation, whereas competence for DNA uptake is likely to contribute to organellar genome dynamics and evolution. Contrary to protein import mechanisms, the way nucleic acids cross the mitochondrial membranes remains poorly understood. Using proteomic, genetic and biochemical approaches with both plant and yeast organelles, we develop here a model for DNA uptake into mitochondria. The first step includes the voltage-dependent anion channel and an outer membrane-located precursor fraction of a protein normally located in the inner membrane. To proceed, the DNA is then potentially recruited in the intermembrane space by an accessible subunit of one of the respiratory chain complexes. Final translocation through the inner membrane remains the most versatile but points to the components considered to make the mitochondrial permeability transition pore. Depending on the size, DNA and RNA cooperate or compete for mitochondrial uptake, which shows that they share import mechanisms. On the other hand, our results imply the existence of more than one route for nucleic acid translocation into mitochondria.
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Weber-Lotfi
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France; Siberian Institute of Plant Physiology and Biochemistry, SB RAS, Ul. Lermontova 132, Irkutsk 664033, Russia.
authors.forename: Milana V
authors.initials: MV
authors.lastname: Koulintchenko
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: Noha
authors.initials: N
authors.lastname: Ibrahim
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Hammann
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France; Siberian Institute of Plant Physiology and Biochemistry, SB RAS, Ul. Lermontova 132, Irkutsk 664033, Russia.
authors.forename: Daria V
authors.initials: DV
authors.lastname: Mileshina
authors.affiliation: Siberian Institute of Plant Physiology and Biochemistry, SB RAS, Ul. Lermontova 132, Irkutsk 664033, Russia.
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Konstantinov
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 Rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: André
authors.initials: A
authors.lastname: Dietrich
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D001692:Biological Transport; D008928:Mitochondria / Q000378:metabolism*; D009696:Nucleic Acids / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D009696:Nucleic Acids
keywords: Import factor; Mitochondria; Nucleic acid transport; Permeability transition pore; Plant; Yeast