LOCALIZATION OF XENOPUS VG1 MESSENGER-RNA BY VERA PROTEIN AND THE ENDOPLASMIC-RETICULUM

In many organisms, pattern formation in the embryo develops from the p olarized distributions of messenger RNAs (mRNAs) in the egg, in Xenopu s, the mRNA encoding Vg1, a growth factor involved in mesoderm inducti on, is localized to the vegetal cortex of oocytes. A protein named Ver a was shown to be involved in Vg1 mRNA localization. Vera cofractionat es with endoplasmic reticulum (ER) membranes, and endogenous Vg1 mRNA is associated with a subcompartment of the ER. Vera may promote mRNA l ocalization in Xenopus oocytes by mediating an interaction between the Vg1 3' untranslated region and the ER subcompartment.