Sequence-Independent Self-Assembly of Germ Granule mRNAs into Homotypic Clusters.

TitleSequence-Independent Self-Assembly of Germ Granule mRNAs into Homotypic Clusters.
Publication TypeJournal Article
Year of Publication2020
AuthorsTrcek, T, Douglas, TE, Grosch, M, Yin, Y, Eagle, WVI, Gavis, ER, Shroff, H, Rothenberg, E, Lehmann, R
JournalMol Cell
Date Published2020 06 04
KeywordsAnimals, Cytoplasmic Granules, Drosophila melanogaster, Drosophila Proteins, Nuclear Proteins, Organelles, Ribonucleoproteins, RNA, RNA Transport, RNA, Messenger

<p>mRNAs enriched in membraneless condensates provide functional compartmentalization within cells. The mechanisms that recruit transcripts to condensates are under intense study; however, how mRNAs organize once they reach a granule remains poorly understood. Here, we report on a self-sorting mechanism by which multiple mRNAs derived from the same gene assemble into discrete homotypic clusters. We demonstrate that in vivo mRNA localization to granules and self-assembly within granules are governed by different mRNA features: localization is encoded by specific RNA regions, whereas self-assembly involves the entire mRNA, does not involve sequence-specific, ordered intermolecular RNA:RNA interactions, and is thus RNA sequence independent. We propose that the ability of mRNAs to self-sort into homotypic assemblies is an inherent property of an messenger ribonucleoprotein (mRNP) that is augmented under conditions that increase RNA concentration, such as upon enrichment in RNA-protein granules, a process that appears conserved in diverse cellular contexts and organisms.</p>

Alternate JournalMol Cell
PubMed ID32464092
PubMed Central IDPMC7325742
Grant ListK99 HD088675 / HD / NICHD NIH HHS / United States
R00 HD088675 / HD / NICHD NIH HHS / United States
R37 HD041900 / HD / NICHD NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States