The current understanding of Ded1p/DDX3 homologs from yeast to human.

DExD/H-box RNA helicases are involved in almost all steps of the eukaryotic mRNA biogenesis. The DEAD-box protein Ded1p/DDX3 is conserved from yeast to human. Various lines of genetic and biochemical evidence have indicated a role of the yeast Ded1p in translation and, most likely, in precursor mRNA splicing as well. In contrast, although recent studies have begun to reveal the function of the mammalian DDX3 in translation control, its exact role remains vague and even controversial. Here, we review these findings and particularly discuss the functional aspects of Ded1p/DDX3 in translation control.