title: Expression of the eRF1 translation termination factor is controlled by an autoregulatory circuit involving readthrough and nonsense-mediated decay in plants.
abstract: When a ribosome reaches a stop codon, the eukaryotic Release Factor 1 (eRF1) binds to the A site of the ribosome and terminates translation. In yeasts and plants, both over- and underexpression of eRF1 lead to altered phenotype indicating that eRF1 expression should be strictly controlled. However, regulation of eRF1 level is still poorly understood. Here we show that expression of plant eRF1 is controlled by a complex negative autoregulatory circuit, which is based on the unique features of the 3΄untranslated region (3΄UTR) of the eRF1-1 transcript. The stop codon of the eRF1-1 mRNA is in a translational readthrough promoting context, while its 3΄UTR induces nonsense-mediated decay (NMD), a translation termination coupled mRNA degradation mechanism. We demonstrate that readthrough partially protects the eRF1-1 mRNA from its 3΄UTR induced NMD, and that elevated eRF1 levels inhibit readthrough and stimulate NMD. Thus, high eRF1 level leads to reduced eRF1-1 expression, as weakened readthrough fails to protect the eRF1-1 mRNA from the more intense NMD. This eRF1 autoregulatory circuit might serve to finely balance general translation termination efficiency.
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Tünde
authors.initials: T
authors.lastname: Nyikó
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Andor
authors.initials: A
authors.lastname: Auber
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Szabadkai
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Anna
authors.initials: A
authors.lastname: Benkovics
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Mariann
authors.initials: M
authors.lastname: Auth
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Mérai
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Kerényi
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dinnyés
authors.affiliation: Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári 62, H-6726, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Nagy
authors.affiliation: Department of Genetics, Agricultural Biotechnology Institute, Gödöllo, Szent-Györgyi 4, H-2100, Hungary.
authors.forename: Dániel
authors.initials: D
authors.lastname: Silhavy
mesh_terms: D020413:3' Untranslated Regions; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D007438:Introns; D008957:Models, Genetic; D059365:Nonsense Mediated mRNA Decay; D010441:Peptide Chain Elongation, Translational; D010443:Peptide Chain Termination, Translational; D010454:Peptide Termination Factors / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D029681:Arabidopsis Proteins; D010454:Peptide Termination Factors; D012333:RNA, Messenger; C494978:eukaryotic release factor 1, Arabidopsis