title: Translational discrimination of ribosomal protein mRNAs in the early Drosophila embryo.
abstract: Most Drosophila mRNAs are actively translated in the early embryo, with the exception of the poorly translated ribosomal protein (r-protein) mRNAs. Two possible mechanisms for this translational discrimination were tested: (1) Translation of r-protein mRNAs is discriminated against by the limited activity of translational initiation factors in the early embryo and (2) translation of r-protein mRNAs is repressed by trans-acting factors that reversibly bind these mRNAs. Exogenously provided initiation factors promoted partial recruitment of r-protein mRNAs into polysomes, suggesting that modulation of initiation factor activity may play a role in the translational discrimination of r-protein mRNAs during embryogenesis. No evidence for involvement of reversibly binding trans-acting factors was obtained, although there are limitations in the interpretation of the latter experiments.
authors.affiliation: Case Western Reserve University, School of Medicine, Department of Genetics, Cleveland, Ohio 44106-4901.
authors.forename: S
authors.initials: S
authors.lastname: Hongo
authors.forename: M
authors.initials: M
authors.lastname: Jacobs-Lorena
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000818:Animals; D015152:Blotting, Northern; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D039601:Eukaryotic Initiation Factor-4A; D039562:Eukaryotic Initiation Factor-4F; D005786:Gene Expression Regulation / Q000187:drug effects; D010448:Peptide Initiation Factors / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D012269:Ribosomal Proteins / Q000096:biosynthesis*; D015534:Trans-Activators / Q000502:physiology
chemical_list: D000199:Actins; D039562:Eukaryotic Initiation Factor-4F; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D015534:Trans-Activators; D039601:Eukaryotic Initiation Factor-4A