Translational discrimination of ribosomal protein mRNAs in the early Drosophila embryo.
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.
Hongo
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Case Western Reserve University, School of Medicine, Department of Genetics, Cleveland, Ohio 44106-4901.
Jacobs-Lorena
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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
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