Xenopus Staufen is a component of a ribonucleoprotein complex containing Vg1 RNA and kinesin

RNA localization is a key mechanism for generating cell and developmental polarity in a wide variety of organisms. We have performed studies to investigate a role for the Xenopus homolog of the double-stranded RNA-binding protein, Staufen, in RNA localization during oogenesis. We have found that Xenopus Staufen (XStau) is present in a ribonucleoprotein complex, and associates with both a kinesin motor protein and vegetally localized RNAs Vg1 and VegT. A functional role for XStau was revealed through expression of a dominant-negative version that blocks localization of Vg1 RNA in vivo. Our results suggest a central role for XStau in RNA localization in Xenopus oocytes, and provide evidence that Staufen is a conserved link between specific mRNAs and the RNA localization machinery.