title: Silencing of the nuclear RPS10 gene encoding mitochondrial ribosomal protein alters translation in arabidopsis mitochondria.
abstract: Hardly anything is known about translational control of plant mitochondrial gene expression. Here, we provide evidence for differential translation of mitochondrial transcripts in Arabidopsis thaliana. We found that silencing of the nuclear RPS10 gene encoding mitochondrial ribosomal protein S10 disturbs the ratio between the small and large subunits of mitoribosomes, with an excess of the latter. Moreover, a portion of the small subunits are incomplete, lacking at least the S10 protein. rps10 cells also have an increased mitochondrial DNA copy number per cell, causing an upregulation of all mitochondrial transcripts. Mitochondrial translation is also altered so that it largely overrides the hyperaccumulation of transcripts, and as a consequence, only ribosomal proteins are oversynthesized, whereas oxidative phosphorylation subunits are downregulated. Expression of nuclear-encoded components of mitoribosomes and oxidative phosphorylation system (OXPHOS) complexes seems to be less affected. The ultimate coordination of expression of the nuclear and mitochondrial genomes occurs at the complex assembly level. These findings indicate that mitoribosomes can regulate gene expression by varying the efficiency of translation of mRNAs for OXPHOS and ribosomal proteins.
authors.affiliation: Department of Biotechnology, University of Wroclaw, 51-148 Wroclaw, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Kwasniak
authors.forename: Pawel
authors.initials: P
authors.lastname: Majewski
authors.forename: Renata
authors.initials: R
authors.lastname: Skibior
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Adamowicz
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Czarna
authors.forename: Elwira
authors.initials: E
authors.lastname: Sliwinska
authors.forename: Hanna
authors.initials: H
authors.lastname: Janska
mesh_terms: D049069:ATP-Dependent Proteases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D005838:Genotype; D015151:Immunoblotting; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D016254:Mutagenesis, Insertional; D010085:Oxidative Phosphorylation; D010641:Phenotype; D030821:Plants, Genetically Modified; D014176:Protein Biosynthesis; D011523:Protoplasts / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D013997:Time Factors; D019076:Transgenes
chemical_list: D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C540796:Rps10 protein, Arabidopsis; D049069:ATP-Dependent Proteases