title: Kinetic analysis reveals the ordered coupling of translation termination and ribosome recycling in yeast.
abstract: Although well defined in bacterial systems, the molecular mechanisms underlying ribosome recycling in eukaryotic cells have only begun to be explored. Recent studies have proposed a direct role for eukaryotic termination factors eRF1 and eRF3 (and the related factors Dom34 and Hbs1) in downstream recycling processes; however, our understanding of the connection between termination and recycling in eukaryotes is limited. Here, using an in vitro reconstituted yeast translation system, we identify a key role for the multifunctional ABC-family protein Rli1 in stimulating both eRF1-mediated termination and ribosome recycling in yeast. Through subsequent kinetic analysis, we uncover a network of regulatory features that provides mechanistic insight into how the events of termination and recycling are obligately ordered. These results establish a model in which eukaryotic termination and recycling are not clearly demarcated events, as they are in bacteria, but coupled stages of the same release-factor mediated process.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Shoemaker
authors.forename: Rachel
authors.initials: R
authors.lastname: Green
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000737:chemistry; D001671:Biochemistry / Q000379:methods; D018797:Cell Cycle Proteins / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D005658:Fungi / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D006868:Hydrolysis; D007700:Kinetics; D016296:Mutagenesis; D010455:Peptides / Q000737:chemistry; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: C501917:ABCE1 protein, human; D018528:ATP-Binding Cassette Transporters; D018797:Cell Cycle Proteins; D010455:Peptides; C492990:RLI1 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C112808:Dom34 protein, S cerevisiae; D004722:Endoribonucleases; D000251:Adenosine Triphosphatases