title: RNA assemblages orchestrate complex cellular processes.
abstract: Eukaryotic mRNAs are monocistronic, and therefore mechanisms exist that coordinate the synthesis of multiprotein complexes in order to obtain proper stoichiometry at the appropriate intracellular locations. RNA-binding proteins containing low-complexity sequences are prone to generate liquid droplets via liquid-liquid phase separation, and in this way create cytoplasmic assemblages of functionally related mRNAs. In a recent iCLIP study, we showed that the Drosophila RNA-binding protein Imp, which exhibits a C-terminal low-complexity sequence, increases the formation of F-actin by binding to 3' untranslated regions of mRNAs encoding components participating in F-actin biogenesis. We hypothesize that phase transition is a mechanism the cell employs to increase the local mRNA concentration considerably, and in this way synchronize protein production in cytoplasmic territories, as discussed in the present review.
authors.affiliation: Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Finn Cilius
authors.initials: FC
authors.lastname: Nielsen
authors.affiliation: Department of Biology, Center for Computational and Applied Transcriptomics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Heidi Theil
authors.initials: HT
authors.lastname: Hansen
authors.affiliation: Department of Biology, Center for Computational and Applied Transcriptomics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Christiansen
mesh_terms: D000818:Animals; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D006801:Humans; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins
keywords: RNA assemblage; RNA-binding protein; RNP granule; liquid droplet; low-complexity sequence; post-transcriptional RNA regulon