Diversity Functions of Puf Proteins in Protozoan Species

In all eukaryotic cells, the regulation of gene expression is accomplished at both transcriptional and translational levels. At the translational level, control of gene expression is often mediated by cis-acting elements in the 3' untranslated region (UTR) of the mRNA. This regulation is achieved through a network of RNA binding proteins (RBPs) that have great effect on stability, localization and translatability of their target mRNA. The Puf family RBPs named after Pumilio (Pum) protein in Drosophila melanogaster and fem-3 binding factor (FBF) protein in Caenorhabditis elegans [1,2], represent a highly conserved group of RBPs found in many organisms including animals, plants, fungi and protists [3-5].