Conserved mRNA-binding proteomes in eukaryotic organisms

RNA-binding proteins (RBPs) are essential for the post-transcriptional regulation of gene expression. Recent high-throughput screens have dramatically increased the number of experimentally identified RBPs; however, comprehensive identification of RBPs within living organisms is elusive. Here we describe the repertoire of 765 and 594 proteins that reproducibly interact with polyadenylated mRNAs in Saccharomyces cerevisiae and Caenorhabditis elegans, respectively. Furthermore, we report the differential association of mRBPs upon apoptosis induction in C. elegans L4 stage larvae. Strikingly, most proteins comprising mRNA-binding proteomes (mRBPomes) are evolutionarily conserved between yeast and C. elegans, including components of early metabolic pathways and the proteasome. Based on our evidence that glycolytic enzymes bind to distinct glycolytic mRNAs, we speculate that enzyme-mRNA interactions relate to an ancient mechanism for post-transcriptional coordination of metabolic pathways, perhaps established during the transition from the early RNA to the protein ‘world’.