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. 1999 Dec;5(12):1535–1547. doi: 10.1017/s1355838299991392

Smaug, a novel and conserved protein, contributes to repression of nanos mRNA translation in vitro.

C A Smibert 1, Y S Lie 1, W Shillinglaw 1, W J Henzel 1, P M Macdonald 1
PMCID: PMC1369876  PMID: 10606265

Abstract

Proper deployment of Nanos protein at the posterior of the Drosophila embryo, where it directs posterior development, requires a combination of RNA localization and translational controls. These controls ensure that only the posteriorly-localized nanos mRNA is translated, whereas unlocalized nanos mRNA is translationally repressed. Here we describe cloning of the gene encoding Smaug, an RNA-binding protein that interacts with the sequences, SREs, in the nanos mRNA that mediate translational repression. Using an in vitro translation assay, we demonstrate that SRE-dependent repression occurs in extracts from early stage embryos. Immunodepletion of Smaug from the extracts eliminates repression, consistent with the notion that Smaug is involved. Smaug is a novel gene and the existence of potential mammalian Smaug homologs raises the possibility that Smaug represents a new class of conserved translational repressor.

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Selected References

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