The splicing of yeast mitochondrial group I and group II introns requires a DEAD-box protein with RNA chaperone function
The splicing of yeast mitochondrial group I and group II introns requires a DEAD-box protein with RNA chaperone function
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DOI：
10.1073/pnas.0407896101
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发表时间：
2005-01-04
影响因子：
11.1
通讯作者：
Perlman, PS
中科院分区：
文献类型：
--
作者：
Huang, HR;Rowe, CE;Perlman, PS
I 组和 II 组内含子在体外进行自剪接，但需要蛋白质在体内进行有效剪接，以稳定催化活性 RNA 结构。最近的研究表明，一些粗糙脉孢菌线粒体 I 组内含子的剪接还需要一种 DEAD-box 蛋白 CYT-19，它充当 RNA 伴侣来解析 RNA 折叠过程中形成的规范结构。在这里，我们表明，在酿酒酵母线粒体中，所有 I 组和 II 组内含子的有效剪接、一些 RNA 末端加工反应以及 mRNA 子集的翻译都需要一种相关的 DEAD-box 蛋白 Mss116p，并且所有这些缺陷都可以通过 CYT-19 的表达部分或完全抑制。 al2 II 组内含子的结果表明，在结合内含子编码的成熟酶后需要 Mss116p，这可能是为了破坏稳定但无活性的 RNA 结构。我们的结果表明，I 组和 II 组内含子在体内 RNA 折叠中都容易出现动力学陷阱，并且两种类型内含子的剪接可能需要充当 RNA 伴侣的 DEAD-box 蛋白。
Group I and II introns self-splice in vitro, but require proteins for efficient splicing in vivo, to stabilize the catalytically active RNA structure. Recent studies showed that the splicing of some Neurospora crassa mitochondrial group I introns additionally requires a DEAD-box protein, CYT-19, which acts as an RNA chaperone to resolve normative structures formed during RNA folding. Here we show that, in Saccharomyces cerevisiae mitochondria, a related DEAD-box protein, Mss116p, is required for the efficient splicing of all group I and II introns, some RNA end-processing reactions, and translation of a subset of mRNAs, and that all these defects can be partially or completely suppressed by the expression of CYT-19. Results for the al2 group II intron indicate that Mss116p is needed after binding the intron-encoded maturase, likely for the disruption of stable but inactive RNA structures. Our results suggest that both group I and II introns are prone to kinetic traps in RNA folding in vivo and that the splicing of both types of introns may require DEAD-box proteins that function as RNA chaperones.