Posttranscriptional regulation of mRNAs is a key aspect of gene expression. Whether a particular mRNA is translated, repressed, or degraded, depends on its interactions with a variety of RNA-binding proteins and regulatory RNAs. We are interested in elucidating how these interactions determine mRNA fates and how posttranscriptional mechanisms control fundamental biological processes. Our research has important biomedical implications for human disorders. Our main experimental models are the nematode Caenorhabditis elegans, which has the advantage of a genetically tractable organism, and mammalian cells. Our interdisciplinary approach combines genetics and genomics with molecular biology, through biochemistry and structural biology.