UPF3 suppresses aberrant spliced mRNA in Arabidopsis
UPF3 suppresses aberrant spliced mRNA in Arabidopsis
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DOI：
10.1111/j.1365-313x.2005.02473.x
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发表时间：
2005-08-01
期刊：
影响因子：
7.2
通讯作者：
Watanabe, Y
中科院分区：
文献类型：
--
作者：
Hori, K;Watanabe, Y
据报道，真核生物具有无义介导的mRNA衰变（NMD）系统，以排除产生截短蛋白的异常mRNA。NMD是一种RNA监视途径，其降解具有过早翻译终止密码子（PTC）的mRNA，从而避免产生可能有毒的截短蛋白。哺乳动物和酵母中的NMD需要三种相互作用的蛋白质：UPF 1、UPF 2和UPF 3，它们的氨基酸序列在包括植物在内的大多数真核生物中非常保守。在这项研究中，“拟南芥信息资源”数据库中搜索的mRNA与提前终止密码子。我们选择了这些mRNA中的五种，并在体内翻译时检查这些mRNA中PTC的存在。因此，我们确定了每个基因的选择性剪接产生的异常mRNA。这些基因产生至少一种选择性剪接变体，包括PTC（PTC+）和另一种没有PTC的变体（PTC-）。我们分析了它们在野生型拟南芥和upf 3突变体植物中的PTC+/PTC-比率，并表明atupf 3突变体植物中的PTC+/PTC-比率高于野生型植物，并且atupf 3突变体比野生型植物更不能够降解具有提前终止密码子的mRNA。这表明AtUPF 3基因是植物NMD系统进行非正常剪接所必需的。
It has been reported that eukaryotic organisms have a nonsense-mediated mRNA decay (NMD) system to exclude aberrant mRNAs that produce truncated proteins. NMD is an RNA surveillance pathway that degrades mRNAs possessing premature translation termination codons (PTCs), thus avoiding production of possibly toxic truncated proteins. Three interacting proteins, UPF1, UPF2 and UPF3, are required for NMD in mammals and yeasts, and their amino acid sequences are well conserved among most eukaryotes, including plants. In this study, 'The Arabidopsis Information Resource' database was searched for mRNAs with premature termination codons. We selected five of these mRNAs and checked for the presence of PTCs in these mRNAs when translated in vivo. As a result we identified aberrant mRNAs produced by alternative splicing for each gene. These genes produced at least one alternative splicing variant including a PTC (PTC+) and another variant without a PTC (PTC-). We analyzed their PTC+/PTC- ratios in wild-type Arabidopsis and upf3 mutant plants and showed that the PTC+/PTC- ratios were higher in atupf3 mutant plants than wild-type plants and that the atupf3 mutant was less able to degrade mRNAs with premature termination codons than wild-type plants. This indicated that the AtUPF3 gene is required by the plant NMD system to obviate aberrantly spliced mRNA.