Overlapping but distinct RNA elements control repression and activation of nanos translation.
Spatially restricted synthesis of Nanos protein in the Drosophila embryo is essential for anterior-posterior patterning. Nanos translation is restricted to the posterior of the embryo by translational repression of nanos mRNA throughout the bulk cytoplasm and selective activation of posteriorly localized nanos mRNA. A 90-nucleotide translational control element (TCE) mediates translational repression. We show that TCE function requires formation of a bipartite secondary structure that is recognized by Smaug repressor and at least one additional factor. We also demonstrate that translational activation requires the interaction of localization factors with sequences that overlap TCE structural motifs. The identification of separate but overlapping recognition motifs for translational repressors and localization factors provides a molecular mechanism for the switch between translational repression and activation.
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Department of Molecular Biology, Princeton University, New Jersey 08544, USA.
Chatterjee
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Gavis
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D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D004330:Drosophila / Q000196:embryology* / Q000235:genetics*; D029721:Drosophila Proteins; D005260:Female; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D014176:Protein Biosynthesis; D016601:RNA-Binding Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D019076:Transgenes; D020798:Two-Hybrid System Techniques
D020413:3' Untranslated Regions; D029721:Drosophila Proteins; D019476:Insect Proteins; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C402587:smg protein, Drosophila; C070574:nos protein, Drosophila