Edelmann Franziska T, Niedner Annika, Niessing Dierk
a Institute of Structural Biology ; Helmholtz Zentrum München - German Center for Environmental Health ; Neuherberg , Germany.
RNA Biol. 2015;12(3):233-7. doi: 10.1080/15476286.2015.1017217.
Asymmetric ASH1 mRNA transport during mitosis of budding yeast constitutes one of the best-studied examples of mRNA localization. Recently, 2 studies used in vitro motility assays to prove that motile ASH1 mRNA-transport complexes can be reconstituted entirely from recombinant factors. Both studies, however, differed in their conclusions on whether cargo RNA itself is required for particle assembly and thus activation of directional transport. Here we provide direct evidence that stable complexes do assemble in absence of RNA at physiologic conditions and even at ionic strengths above cellular levels. These results directly confirm the previous notion that the ASH1 transport machinery is not activated by the cargo RNA itself, but rather through protein-protein interactions.
在出芽酵母有丝分裂过程中，不对称的ASH1信使核糖核酸（mRNA）转运是研究最为深入的mRNA定位实例之一。最近，有两项研究采用体外运动分析来证明，可完全由重组因子重建具有运动性的ASH1 mRNA转运复合体。然而，这两项研究在货物RNA本身是否为颗粒组装以及定向转运激活所必需这一问题上得出了不同结论。在此，我们提供了直接证据，表明在生理条件下，甚至在高于细胞内水平的离子强度下，稳定的复合体在没有RNA的情况下也能组装。这些结果直接证实了先前的观点，即ASH1转运机制不是由货物RNA本身激活的，而是通过蛋白质-蛋白质相互作用激活的。
