title: The MTL1 Pentatricopeptide Repeat Protein Is Required for Both Translation and Splicing of the Mitochondrial NADH DEHYDROGENASE SUBUNIT7 mRNA in Arabidopsis.
abstract: Mitochondrial translation involves a complex interplay of ancient bacteria-like features and host-derived functionalities. Although the basic components of the mitochondrial translation apparatus have been recognized, very few protein factors aiding in recruiting ribosomes on mitochondria-encoded messenger RNA (mRNAs) have been identified in higher plants. In this study, we describe the identification of the Arabidopsis (Arabidopsis thaliana) MITOCHONDRIAL TRANSLATION FACTOR1 (MTL1) protein, a new member of the Pentatricopeptide Repeat family, and show that it is essential for the translation of the mitochondrial NADH dehydrogenase subunit7 (nad7) mRNA. We demonstrate that mtl1 mutant plants fail to accumulate the Nad7 protein, even though the nad7 mature mRNA is produced and bears the same 5' and 3' extremities as in wild-type plants. We next observed that polysome association of nad7 mature mRNA is specifically disrupted in mtl1 mutants, indicating that the absence of Nad7 results from a lack of translation of nad7 mRNA. These findings illustrate that mitochondrial translation requires the intervention of gene-specific nucleus-encoded PPR trans-factors and that their action does not necessarily involve the 5' processing of their target mRNA, as observed previously. Interestingly, a partial decrease in nad7 intron 2 splicing was also detected in mtl1 mutants, suggesting that MTL1 is also involved in group II intron splicing. However, this second function appears to be less essential for nad7 expression than its role in translation. MTL1 will be instrumental to understand the multifunctionality of PPR proteins and the mechanisms governing mRNA translation and intron splicing in plant mitochondria.
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Nawel
authors.initials: N
authors.lastname: Haïli
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Noelya
authors.initials: N
authors.lastname: Planchard
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Nadège
authors.initials: N
authors.lastname: Arnal
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Martine
authors.initials: M
authors.lastname: Quadrado
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vrielynck
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Jennifer
authors.initials: J
authors.lastname: Dahan
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.).
authors.forename: Catherine Colas
authors.identifier: http://orcid.org/0000-0002-6386-5672
authors.initials: CC
authors.lastname: des Francs-Small
authors.affiliation: Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, AgroParisTech, Centre National de la Recherche Scientifique, Université Paris-Saclay, 78026 Versailles cedex, France (N.H., N.P., N.A., M.Q., N.V., J.D., H.M.);Université Paris-Sud, Université Paris-Saclay, 91405 Orsay cedex, France (N.H., N.P.); andAustralian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia 6009, Australia (C.C.d.F.-S.) hakim.mireau@versailles.inra.fr.
authors.forename: Hakim
authors.identifier: http://orcid.org/0000-0002-2299-5139
authors.initials: H
authors.lastname: Mireau
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007438:Introns; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009245:NADH Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011132:Polyribosomes / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D000077278:RNA, Mitochondrial
chemical_list: D029681:Arabidopsis Proteins; C000610873:MTL1 protein, Arabidopsis; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; C029305:mitochondrial messenger RNA; C560633:NAD7 protein, Arabidopsis; D009245:NADH Dehydrogenase