Regulation of RNA granule dynamics by phosphorylation of serine-rich, intrinsically disordered proteins in C. elegans.

Author: Wang JT1, Smith J1, Chen BC2, Schmidt H1, Rasoloson D1, Paix A1, Lambrus BG1, Calidas D1, Betzig E3, Seydoux G1.
Affiliation:
1Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States. 2Research Center for Applied Sciences, Academica Sinica, Taipei, Taiwan. 3Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States.
Conference/Journal: Elife.
Date published: 2014 Dec 23
Other: Special Notes: doi: 10.7554/eLife.04591 , Word Count: 179


Abstract
RNA granules have been likened to liquid droplets whose dynamics depend on the controlled dissolution and condensation of internal components. The molecules and reactions that drive these dynamics in vivo are not well understood. In this study, we present evidence that a group of intrinsically disordered, serine-rich proteins regulate the dynamics of P granules in C. elegans embryos. The MEG (maternal-effect germline defective) proteins are germ plasm components that are required redundantly for fertility. We demonstrate that MEG-1 and MEG-3 are substrates of the kinase MBK-2/DYRK and the phosphatase PP2APPTR-½. Phosphorylation of the MEGs promotes granule disassembly and dephosphorylation promotes granule assembly. Using lattice light sheet microscopy on live embryos, we show that GFP-tagged MEG-3 localizes to a dynamic domain that surrounds and penetrates each granule. We conclude that, despite their liquid-like behavior, P granules are non-homogeneous structures whose assembly in embryos is regulated by phosphorylation.
KEYWORDS:
C. elegans; RNA granules; cell biology; developmental biology; germ plasm; intrinsically disordered proteins; stem cells
PMID: 25535836

http://www.newswise.com/articles/view/628316/?sc=swhn

http://elifesciences.org/content/3/e04591

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