title: Ribosomal protein S1 influences trans-translation in vitro and in vivo.
abstract: When the bacterial ribosome stalls on a truncated mRNA, transfer-messenger RNA (tmRNA) acts initially as a transfer RNA (tRNA) and then as a messenger RNA (mRNA) to rescue the ribosome and add a peptide tag to the nascent polypeptide that targets it for degradation. Ribosomal protein S1 binds tmRNA but its functional role in this process has remained elusive. In this report, we demonstrate that, in vitro, S1 is dispensable for the tRNA-like role of tmRNA but is essential for its mRNA function. Increasing or decreasing the amount of protein S1 in vivo reduces the overall amount of trans-translated proteins. Also, a truncated S1 protein impaired for ribosome binding can still trigger protein tagging, suggesting that S1 interacts with tmRNA outside the ribosome to keep it in an active state. Overall, these results demonstrate that S1 has a role in tmRNA-mediated tagging that is distinct from its role during canonical translation.
authors: Université de Rennes 1, UPRES 2311, Inserm U835, Biochimie Pharmaceutique, Rennes, France.
authors: Matthieu
authors: M
authors: Saguy
authors: Reynald
authors: R
authors: Gillet
authors: Patricia
authors: P
authors: Skorski
authors: Sylvie
authors: S
authors: Hermann-Le Denmat
authors: Brice
authors: B
authors: Felden
mesh_terms: D003062:Codon; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000502:physiology*; D012270:Ribosomes / Q000378:metabolism
chemical_list: D003062:Codon; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C015494:ribosomal protein S1; C096222:tmRNA