The RNA-Binding ATPase, Armitage, Couples piRNA Amplification in Nuage to Phased piRNA Production on Mitochondria
The RNA-Binding ATPase, Armitage, Couples piRNA Amplification in Nuage to Phased piRNA Production on Mitochondria
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DOI：
10.1016/j.molcel.2019.04.006
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发表时间：
2019-06-06
期刊：
影响因子：
16
通讯作者：
Zamore, Phillip D.
中科院分区：
文献类型：
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作者：
Ge, Daniel Tianfang;Wang, Wei;Zamore, Phillip D.
PIWI相互作用RNA（piRNA）沉默果蝇卵巢中的转座子，确保雌性生育力。两种偶联的途径产生生殖系piRNA：乒乓循环，其中PIWI蛋白Aubergine和Ago3增加预先存在的piRNA的丰度，以及阶段性皮尔纳途径，其一个接一个地产生尾对头piRNA串。在乒乓循环中起作用的蛋白质定位于nuage，而分阶段的皮尔纳产生需要小西葫芦，一种线粒体表面上的内切核酸酶。在这里，我们报告了Armitage（Armi），一种定位于nuage和线粒体的RNA结合ATP酶，将乒乓循环与阶段性皮尔纳途径联系起来。阻断阶段性皮尔纳产生的突变使Armi从nuage中耗尽。Armi ATP酶突变体不能支持分阶段的皮尔纳产生，并且不适当地结合mRNA而不是皮尔纳前体。我们提出Armi在nuage和线粒体之间穿梭，将Ago3切割产生的前体piRNA喂入线粒体表面上茄子和Piwi结合的piRNA的Zucchini依赖性生产中。
PIWI-interacting RNAs (piRNAs) silence transposons in Drosophila ovaries, ensuring female fertility. Two coupled pathways generate germline piRNAs: the ping-pong cycle, in which the PIWI proteins Aubergine and Ago3 increase the abundance of pre-existing piRNAs, and the phased piRNA pathway, which generates strings of tail-to-head piRNAs, one after another. Proteins acting in the ping-pong cycle localize to nuage, whereas phased piRNA production requires Zucchini, an endonuclease on the mitochondrial surface. Here, we report that Armitage (Armi), an RNA-binding ATPase localized to both nuage and mitochondria, links the ping-pong cycle to the phased piRNA pathway. Mutations that block phased piRNA production deplete Armi from nuage. Armi ATPase mutants cannot support phased piRNA production and inappropriately bind mRNA instead of piRNA precursors. We propose that Armi shuttles between nuage and mitochondria, feeding precursor piRNAs generated by Ago3 cleavage into the Zucchini-dependent production of Aubergine- and Piwi-bound piRNAs on the mitochondrial surface.