Pat1 promotes processing body assembly by enhancing the phase separation of the DEAD-box ATPase Dhh1 and RNA
Abstract
Processing bodies (PBs) are cytoplasmic mRNP granules that assemble via liquid-liquid phase separation and are implicated in the decay or storage of mRNAs. How PB assembly is regulated in cells remains unclear. Previously, we identified the ATPase activity of the DEAD-box protein Dhh1 as a key regulator of PB dynamics and demonstrated that Not1, an activator of the Dhh1 ATPase and member of the CCR4-NOT deadenylase complex inhibits PB assembly in vivo (Mugler et al., 2016). Here, we show that the PB component Pat1 antagonizes Not1 and promotes PB assembly via its direct interaction with Dhh1. Intriguingly, in vivo PB dynamics can be recapitulated in vitro, since Pat1 enhances the phase separation of Dhh1 and RNA into liquid droplets, whereas Not1 reverses Pat1-Dhh1-RNA condensation. Overall, our results uncover a function of Pat1 in promoting the multimerization of Dhh1 on mRNA, thereby aiding the assembly of large multivalent mRNP granules that are PBs.
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All data generated or analysed during this study are included in the manuscript and supporting files.
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Funding
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (31003A_159731)
- Karsten Weis
National Institute of General Medical Sciences (R01GM058065)
- Karsten Weis
National Institute of General Medical Sciences (R01GM101257)
- Karsten Weis
Human Frontier Science Program (LT000914/2015)
- Maria Hondele
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (31003A_179275)
- Karsten Weis
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Alan G Hinnebusch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States
Version history
- Received: August 28, 2018
- Accepted: January 15, 2019
- Accepted Manuscript published: January 16, 2019 (version 1)
- Version of Record published: February 7, 2019 (version 2)
Copyright
© 2019, Sachdev et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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