title: MPV17L2 is required for ribosome assembly in mitochondria.
abstract: MPV17 is a mitochondrial protein of unknown function, and mutations in MPV17 are associated with mitochondrial deoxyribonucleic acid (DNA) maintenance disorders. Here we investigated its most similar relative, MPV17L2, which is also annotated as a mitochondrial protein. Mitochondrial fractionation analyses demonstrate MPV17L2 is an integral inner membrane protein, like MPV17. However, unlike MPV17, MPV17L2 is dependent on mitochondrial DNA, as it is absent from ρ(0) cells, and co-sediments on sucrose gradients with the large subunit of the mitochondrial ribosome and the monosome. Gene silencing of MPV17L2 results in marked decreases in the monosome and both subunits of the mitochondrial ribosome, leading to impaired protein synthesis in the mitochondria. Depletion of MPV17L2 also induces mitochondrial DNA aggregation. The DNA and ribosome phenotypes are linked, as in the absence of MPV17L2 proteins of the small subunit of the mitochondrial ribosome are trapped in the enlarged nucleoids, in contrast to a component of the large subunit. These findings suggest MPV17L2 contributes to the biogenesis of the mitochondrial ribosome, uniting the two subunits to create the translationally competent monosome, and provide evidence that assembly of the small subunit of the mitochondrial ribosome occurs at the nucleoid.
authors.affiliation: MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Dalla Rosa
authors.affiliation: MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Romina
authors.initials: R
authors.lastname: Durigon
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Pearce
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Rorbach
authors.affiliation: MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Elizabeth M A
authors.initials: EM
authors.lastname: Hirst
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Sara
authors.initials: S
authors.lastname: Vidoni
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Reyes
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Gloria
authors.initials: G
authors.lastname: Brea-Calvo
authors.affiliation: MRC Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Michal
authors.initials: M
authors.lastname: Minczuk
authors.affiliation: Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Woellhaf
authors.affiliation: Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Herrmann
authors.affiliation: Centre for Molecular and Biomolecular Informatics, Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Netherlands.
authors.forename: Martijn A
authors.initials: MA
authors.lastname: Huynen
authors.affiliation: MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Holt
authors.affiliation: MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK aspinaz@nimr.mrc.ac.uk.
authors.forename: Antonella
authors.initials: A
authors.lastname: Spinazzola
mesh_terms: D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008928:Mitochondria / Q000737:chemistry / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008933:Mitochondrial Swelling; D014176:Protein Biosynthesis; D054683:Ribosome Subunits, Large, Eukaryotic / Q000737:chemistry; D012270:Ribosomes / Q000378:metabolism*
chemical_list: C530370:MPV17 protein, human; C000592357:MPV17L2 protein, human; D008565:Membrane Proteins; D024101:Mitochondrial Proteins