Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
RNA. 2013 Jul;19(7):889-95. doi: 10.1261/rna.038232.113. Epub 2013 May 3.
The 3' untranslated region of mRNA encoding PHAX, a phosphoprotein required for nuclear export of U-type snRNAs, contains cis-acting sequence motifs E2 and VM1 that are required for localization of RNAs to the vegetal hemisphere of Xenopus oocytes. However, we have found that PHAX mRNA is transported to the opposite, animal, hemisphere. A set of proteins that cross-link to the localization elements of vegetally localized RNAs are also cross-linked to PHAX and An1 mRNAs, demonstrating that the composition of RNP complexes that form on these localization elements is highly conserved irrespective of the final destination of the RNA. The ability of RNAs to bind this core group of proteins is correlated with localization activity. Staufen1, which binds to Vg1 and VegT mRNAs, is not associated with RNAs localized to the animal hemisphere and may determine, at least in part, the direction of RNA movement in Xenopus oocytes.
mRNA 的 3'非翻译区编码 PHAX，这是一种磷酸蛋白，对于 U 型 snRNA 的核输出是必需的，它包含顺式作用序列基序 E2 和 VM1，这些序列基序对于将 RNA 定位到爪蟾卵母细胞的植物半球是必需的。然而，我们已经发现 PHAX mRNA 被运输到相反的动物半球。一组与植物定位 RNA 的定位元件交联的蛋白质也与 PHAX 和 An1 mRNA 交联，这表明形成这些定位元件上的 RNP 复合物的组成高度保守，与 RNA 的最终目的地无关。RNA 结合这个核心蛋白组的能力与定位活性相关。与 Vg1 和 VegT mRNA 结合的 Staufen1 与定位到动物半球的 RNA 没有关联，并且可能至少部分决定了 RNA 在爪蟾卵母细胞中的运动方向。
