title: Targeting of cytosolic mRNA to mitochondria: naked RNA can bind to the mitochondrial surface.
abstract: Mitochondria contain hundreds of proteins but only a few are encoded by the mitochondrial genome. The other proteins are nuclear-encoded and imported into mitochondria. These proteins can be translated on free cytosolic polysomes, then targeted and imported into mitochondria. Nonetheless, numerous cytosolic mRNAs encoding mitochondrial proteins are detected at the surface of mitochondria in yeast, plants and animals. The localization of mRNAs to the vicinity of mitochondria would be a way for mitochondrial protein sorting. The mechanisms responsible for mRNA targeting to mitochondria are not clearly identified. Sequences within the mRNA molecules (cis-elements), as well as a few trans-acting factors, have been shown to be essential for targeting of some mRNAs. In order to identify receptors involved in mRNA docking to the mitochondrial surface, we have developed an in vitro mRNA binding assay with isolated plant mitochondria. We show that naked mRNAs are able to bind to isolated mitochondria, and our results strongly suggest that mRNA docking to the plant mitochondrial outer membrane requires at least one component of TOM complex.
authors.affiliation: Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: Morgane
authors.initials: M
authors.lastname: Michaud
authors.affiliation: Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Maréchal-Drouard
authors.affiliation: Institut de Biologie Moléculaire des Plantes, UPR 2357 du CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France. Electronic address: anne-marie.duchene@ibmp-cnrs.unistra.fr.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Duchêne
mesh_terms: D001665:Binding Sites; D001692:Biological Transport; D003600:Cytosol / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D059828:Plant Cells / Q000378:metabolism; D035281:Plant Tubers / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000077278:RNA, Mitochondrial; D011198:Solanum tuberosum / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D050994:Voltage-Dependent Anion Channels / Q000235:genetics / Q000378:metabolism
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D050994:Voltage-Dependent Anion Channels; D012313:RNA
keywords: Mitochondria; Plant; Protein targeting; TOM; VDAC; mRNA localization; mRNA sorting