Intrinsic and regulated properties of minimally edited trypanosome mRNAs.
Intrinsic and regulated properties of minimally edited trypanosome mRNAs.
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最低限度编辑的锥虫 mRNA 的内在和调控特性。
DOI：
10.1093/nar/gkz012
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发表时间：
2019
影响因子：
14.9
通讯作者：
Read,LaurieK
中科院分区：
文献类型：
--
作者：
Tylec,BriannaL;Simpson,RachelM;Kirby,LauraE;Chen,Runpu;Sun,Yijun;Koslowsky,DonnaJ;Read,LaurieK
着丝质体中的大多数线粒体mrna需要广泛的尿苷插入/删除编辑来生成可翻译的开放阅读框。编辑是由反式作用的grna指定的，涉及包括基础因子和辅助因子在内的复杂机制。在这里，我们利用高通量测序来分析两个最低限度编辑mrna的编辑过程，这提供了一个简化的系统，因为它们只需要两个grna来完成编辑。我们发现CYb和MURF2 mrna表现出与先前鉴定的泛编辑mrna不同的编辑进展障碍，主要是在初始gRNA使用和gRNA交换中。我们证明了错误编辑的连接通过多种途径产生，包括同源gRNA的错误对准，错误和有时混杂的gRNA利用以及低效的gRNA锚定。然后，我们研究了辅助因子RBP16和MRP1/2在维持编辑过的CYb和MURF2群体中的作用。RBP16对于CYb和MURF2编辑的启动以及MURF2编辑的进展至关重要。相比之下，MRP1/2稳定了两个编辑过的mRNA群体，同时进一步促进了MURF2 mRNA编辑的进展。我们还分析了RNA编辑底物结合复合物组分TbRGG2和GAP1的作用，并表明这两种蛋白对最低限度编辑mrna的编辑进展有轻微影响，这表明GAP1具有新的功能。
Most mitochondrial mRNAs in kinetoplastids require extensive uridine insertion/deletion editing to generate translatable open reading frames. Editing is specified bytrans-acting gRNAs and involves a complex machinery including basal and accessory factors. Here, we utilize high-throughput sequencing to analyze editing progression in two minimally edited mRNAs that provide a simplified system due their requiring only two gRNAs each for complete editing. We show that CYb and MURF2 mRNAs exhibit barriers to editing progression that differ from those previously identified for pan-edited mRNAs, primarily at initial gRNA usage and gRNA exchange. We demonstrate that mis-edited junctions arise through multiple pathways including mis-alignment of cognate gRNA, incorrect and sometimes promiscuous gRNA utilization and inefficient gRNA anchoring. We then examined the roles of accessory factors RBP16 and MRP1/2 in maintaining edited CYb and MURF2 populations. RBP16 is essential for initiation of CYb and MURF2 editing, as well as MURF2 editing progression. In contrast, MRP1/2 stabilizes both edited mRNA populations, while further promoting progression of MURF2 mRNA editing. We also analyzed the effects of RNA Editing Substrate Binding Complex components, TbRGG2 and GAP1, and show that both proteins modestly impact progression of editing on minimally edited mRNAs, suggesting a novel function for GAP1.