van Lipzig R, Van Montagu M, Cornelissen M, Meulewaeter F
Vakgroep Moleculaire Genetica, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
Nucleic Acids Res. 2001 Mar 1;29(5):1080-6. doi: 10.1093/nar/29.5.1080.
The satellite tobacco necrosis virus RNA is uncapped and requires a 3' translational enhancer domain (TED) for translation. Both in the wheat germ extract and in tobacco, TED stimulates in cis translation of heterologous, uncapped RNAs. In this study we investigated to what extent translation stimulation by TED depends on binding to wheat germ factors. We show that in vitro TED binds at least seven wheat germ proteins. Translation and crosslinking assays, to which TED or TED derivatives with reduced functionality were included as competitor, showed that TED function correlates with binding to a 28 kDa protein (p28). One particular condition of competition revealed that p28 binding is not obligatory for TED function. Under this condition, a 30 kDa protein (p30) binds to TED. Importantly, affinity of p30 correlates with functionality of TED. These results strongly suggest that TED has the capacity to stimulate translation by recruiting the translational machinery either via binding to p28 or via binding to p30.
卫星烟草坏死病毒RNA无帽结构，翻译需要一个3'端翻译增强子结构域（TED）。在小麦胚芽提取物和烟草中，TED均能顺式刺激异源无帽RNA的翻译。在本研究中，我们调查了TED对翻译的刺激作用在多大程度上依赖于与小麦胚芽因子的结合。我们发现，在体外，TED能结合至少七种小麦胚芽蛋白。将TED或功能降低的TED衍生物作为竞争者纳入翻译和交联试验，结果表明TED的功能与和一种28 kDa蛋白（p28）的结合相关。一种特殊的竞争条件显示，p28结合对于TED功能并非必不可少。在此条件下，一种30 kDa蛋白（p30）与TED结合。重要的是，p30的亲和力与TED的功能相关。这些结果有力地表明，TED能够通过与p28结合或与p30结合来招募翻译机器，从而刺激翻译。
