The functions of y-box binding proteins in caenorhabditis elegans

Members of the highly conserved family of Y-box binding proteins (YBPs) have a broad
spectrum of functions in both transcriptional and post-transcriptional regulation of gene
expression. However, most information comes from in vitro or single cell experimental
systems. In addition, these proteins have not been studied in one of the major model
organisms, Caenorhabditis elegans. Here, we provide a functional characterization of YBPs
in this nematode, thereby also generally adding to the very scarce knowledge on the
developmental functions of YBPs in a multicellular context. Our data suggests a conserved
and essential role for C. elegans YBPs (CEYs) in packaging and stabilizing maternal mRNAs
during oogenesis. In the soma, the absence of CEYs also affects the abundance of many
messages, interestingly, with a strong bias for highly translated mRNAs. The most striking
observation is the soma-specific requirement for CEY proteins to accumulate large
polysomes. Surprisingly, this loss has no negative impact on translation rates and cey mutant
animals show no apparent defects in somatic development. Finally, our data also suggests a
potentially novel function for YBPs, namely, a direct involvement in ribosome biology.