title: The Pet309 pentatricopeptide repeat motifs mediate efficient binding to the mitochondrial COX1 transcript in yeast.
abstract: Mitochondrial synthesis of Cox1, the largest subunit of the cytochrome c oxidase complex, is controlled by Mss51 and Pet309, two mRNA-specific translational activators that act via the COX1 mRNA 5'-UTR through an unknown mechanism. Pet309 belongs to the pentatricopeptide repeat (PPR) protein family, which is involved in RNA metabolism in mitochondria and chloroplasts, and its sequence predicts at least 12 PPR motifs in the central portion of the protein. Deletion of these motifs selectively disrupted translation but not accumulation of the COX1 mRNA. We used RNA coimmunoprecipitation assays to show that Pet309 interacts with the COX1 mRNA in vivo and that this association is present before processing of the COX1 mRNA from the ATP8/6 polycistronic mRNA. This association was not affected by deletion of 8 of the PPR motifs but was undetectable after deletion of the entire 12-PPR region. However, interaction of the Pet309 protein lacking 12 PPR motifs with the COX1 mRNA was detected after overexpression of the mutated form of the protein, suggesting that deletion of this region decreased the binding affinity for the COX1 mRNA without abolishing it entirely. Moreover, binding of Pet309 to the COX1 mRNA was affected by deletion of Mss51. This work demonstrates an in vivo physical interaction between a yeast mitochondrial translational activator and its target mRNA and shows the cooperativity of the PPR domains of Pet309 in interaction with the COX1 mRNA.
authors.affiliation: Departamento de Genética Molecular; Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México.
authors.forename: Angélica
authors.initials: A
authors.lastname: Zamudio-Ochoa
authors.affiliation: Departamento de Genética Molecular; Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Camacho-Villasana
authors.affiliation: Departamento de Genética Molecular; Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México.
authors.forename: Aldo E
authors.initials: AE
authors.lastname: García-Guerrero
authors.affiliation: Departamento de Genética Molecular; Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México.
authors.forename: Xochitl
authors.initials: X
authors.lastname: Pérez-Martínez
mesh_terms: D001665:Binding Sites; D003576:Electron Transport Complex IV / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics
chemical_list: D008565:Membrane Proteins; D024101:Mitochondrial Proteins; C519191:Mss51 protein, S cerevisiae; C095480:PET309 protein, S cerevisiae; D010448:Peptide Initiation Factors; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C526453:Cox1 protein, S cerevisiae; D003576:Electron Transport Complex IV
keywords: COX1mRNA; cytochrome coxidase; mitochondria; pentatricopeptide repeat; translation; yeast