Daedalus and Gasz recruit Armitage to mitochondria, bringing piRNA precursors to the biogenesis machinery
- Marzia Munafò,
- Vera Manelli,
- Federica A. Falconio,
- Ashley Sawle,
- Emma Kneuss,
- Evelyn L. Eastwood,
- Jun Wen Eugene Seah,
- Benjamin Czech and
- Gregory J. Hannon
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge CB2 0RE, United Kingdom
- Corresponding authors: greg.hannon{at}cruk.cam.ac.uk, benjamin.czech{at}cruk.cam.ac.uk
Abstract
The Piwi-interacting RNA (piRNA) pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. piRNA biogenesis requires a specialized machinery that converts long single-stranded precursors into small RNAs of ∼25-nucleotides in length. This process involves factors that operate in two different subcellular compartments: the nuage/Yb body and mitochondria. How these two sites communicate to achieve accurate substrate selection and efficient processing remains unclear. Here, we investigate a previously uncharacterized piRNA biogenesis factor, Daedalus (Daed), that is located on the outer mitochondrial membrane. Daed is essential for Zucchini-mediated piRNA production and the correct localization of the indispensable piRNA biogenesis factor Armitage (Armi). We found that Gasz and Daed interact with each other and likely provide a mitochondrial “anchoring platform” to ensure that Armi is held in place, proximal to Zucchini, during piRNA processing. Our data suggest that Armi initially identifies piRNA precursors in nuage/Yb bodies in a manner that depends on Piwi and then moves to mitochondria to present precursors to the mitochondrial biogenesis machinery. These results represent a significant step in understanding a critical aspect of transposon silencing; namely, how RNAs are chosen to instruct the piRNA machinery in the nature of its silencing targets.
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Footnotes
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Supplemental material is available for this article.
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Article published online ahead of print. Article and publication date are online at http://www.genesdev.org/cgi/doi/10.1101/gad.325662.119.
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Freely available online through the Genes & Development Open Access option.
- Received February 18, 2019.
- Accepted April 16, 2019.
This article, published in Genes & Development, is available under a Creative Commons License (Attribution 4.0 International), as described at http://creativecommons.org/licenses/by/4.0/.