title: The Reverse Transcriptase/RNA Maturase Protein MatR Is Required for the Splicing of Various Group II Introns in Brassicaceae Mitochondria.
abstract: Group II introns are large catalytic RNAs that are ancestrally related to nuclear spliceosomal introns. Sequences corresponding to group II RNAs are found in many prokaryotes and are particularly prevalent within plants organellar genomes. Proteins encoded within the introns themselves (maturases) facilitate the splicing of their own host pre-RNAs. Mitochondrial introns in plants have diverged considerably in sequence and have lost their maturases. In angiosperms, only a single maturase has been retained in the mitochondrial DNA: the matR gene found within NADH dehydrogenase 1 (nad1) intron 4. Its conservation across land plants and RNA editing events, which restore conserved amino acids, indicates that matR encodes a functional protein. However, the biological role of MatR remains unclear. Here, we performed an in vivo investigation of the roles of MatR in Brassicaceae. Directed knockdown of matR expression via synthetically designed ribozymes altered the processing of various introns, including nad1 i4. Pull-down experiments further indicated that MatR is associated with nad1 i4 and several other intron-containing pre-mRNAs. MatR may thus represent an intermediate link in the gradual evolutionary transition from the intron-specific maturases in bacteria into their versatile spliceosomal descendants in the nucleus. The similarity between maturases and the core spliceosomal Prp8 protein further supports this intriguing theory.
authors.affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel.
authors.forename: Laure D
authors.initials: LD
authors.lastname: Sultan
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 67084 Strasbourg, France.
authors.forename: Daria
authors.identifier: 0000-0002-6090-519X
authors.initials: D
authors.lastname: Mileshina
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68588.
authors.forename: Felix
authors.initials: F
authors.lastname: Grewe
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Rolle
authors.affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel.
authors.forename: Sivan
authors.initials: S
authors.lastname: Abudraham
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland.
authors.forename: Paweł
authors.identifier: 0000-0003-1140-7095
authors.initials: P
authors.lastname: Głodowicz
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 67084 Strasbourg, France.
authors.forename: Adnan Khan
authors.identifier: 0000-0002-9006-7377
authors.initials: AK
authors.lastname: Niazi
authors.affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel.
authors.forename: Ido
authors.identifier: 0000-0002-1872-8337
authors.initials: I
authors.lastname: Keren
authors.affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel.
authors.forename: Sofia
authors.initials: S
authors.lastname: Shevtsov
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Liron
authors.initials: L
authors.lastname: Klipcan
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Barciszewski
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68588.
authors.forename: Jeffrey P
authors.identifier: 0000-0002-1501-5809
authors.initials: JP
authors.lastname: Mower
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 67084 Strasbourg, France.
authors.forename: André
authors.initials: A
authors.lastname: Dietrich
authors.affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel oren.ostersetzer@mail.huji.ac.il.
authors.forename: Oren
authors.identifier: 0000-0003-2197-7729
authors.initials: O
authors.lastname: Ostersetzer-Biran
mesh_terms: D019607:Brassicaceae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D007438:Introns / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing / Q000235:genetics / Q000502:physiology; D012194:RNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D009713:Nucleotidyltransferases; C034038:mRNA maturase; D012194:RNA-Directed DNA Polymerase; D004722:Endoribonucleases