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

作者：Craig A. Smibert, Yung S. Lie, Wendy Shillinglaw, William J. Henzel, Paul M. Macdonald · 发表于：RNA · 年份：1999 · DOI：10.1017/s1355838299991392 · 被引用次数：152 · 研究领域：RNA Research and Splicing、RNA and protein synthesis mechanisms、RNA modifications and cancer

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.