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Milano SN, Bayer LV, Ko JJ, Casella CE, Bratu DP. The role of ER exit sites in maintaining P-body organization and transmitting ER stress response during Drosophila melanogaster oogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.03.601952. [PMID: 39005311 PMCID: PMC11245038 DOI: 10.1101/2024.07.03.601952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Processing bodies (P-bodies) are cytoplasmic membrane-less organelles which host multiple mRNA processing events. While the fundamental principles of P-body organization are beginning to be elucidated in vitro, a nuanced understanding of how their assembly is regulated in vivo remains elusive. Here, we investigate the potential link between ER exit sites and P-bodies in Drosophila melanogaster egg chambers. Employing a combination of live and super-resolution imaging, we found that P-bodies associated with ER exit sites are larger and less mobile than cytoplasmic P-bodies, indicating that they constitute a distinct class of P-bodies which are more mature than their cytoplasmic counterparts. Moreover, we demonstrate that altering the composition of ER exit sites has differential effects on core P-body proteins (Me31B, Cup, and Trailer Hitch) suggesting a potential role for ER exit sites in P-body organization. We further show that in the absence of ER exit sites, P-body integrity is compromised and the stability and translational repression efficiency of the maternal mRNA, oskar, are reduced. Finally, we show that ER stress is communicated to P-bodies via ER exit sites, highlighting the pivotal role of ER exit sites as a bridge between membrane-bound and membrane-less organelles in ER stress response. Together, our data unveils the significance of ER exit sites not only in governing P-body organization, but also in facilitating inter-organellar communication during stress, potentially bearing implications for a variety of disease pathologies.
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Affiliation(s)
- Samantha N. Milano
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, NY, 10016 USA
| | - Livia V. Bayer
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Julie J. Ko
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Caroline E. Casella
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
| | - Diana P. Bratu
- Department of Biological Sciences, Hunter College, City University of New York, NY, 10065 USA
- Program in Molecular, Cellular, and Developmental Biology, The Graduate Center, City University of New York, NY, 10016 USA
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2
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Chen R, Stainier W, Dufourt J, Lagha M, Lehmann R. Direct observation of translational activation by a ribonucleoprotein granule. Nat Cell Biol 2024:10.1038/s41556-024-01452-5. [PMID: 38965420 DOI: 10.1038/s41556-024-01452-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 05/30/2024] [Indexed: 07/06/2024]
Abstract
Biomolecular condensates organize biochemical processes at the subcellular level and can provide spatiotemporal regulation within a cell. Among these, ribonucleoprotein (RNP) granules are storage hubs for translationally repressed mRNA. Whether RNP granules can also activate translation and how this could be achieved remains unclear. Here, using single-molecule imaging, we demonstrate that the germ cell-determining RNP granules in Drosophila embryos are sites for active translation of nanos mRNA. Nanos translation occurs preferentially at the germ granule surface with the 3' UTR buried within the granule. Smaug, a cytosolic RNA-binding protein, represses nanos translation, which is relieved when Smaug is sequestered to the germ granule by the scaffold protein Oskar. Together, our findings uncover a molecular process by which RNP granules achieve localized protein synthesis through the compartmentalized loss of translational repression.
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Affiliation(s)
- Ruoyu Chen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Vilcek Institute of Graduate Studies, NYU School of Medicine, New York, NY, USA
| | - William Stainier
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Immunobiology Laboratory, The Francis Crick Institute, London, UK
| | - Jeremy Dufourt
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, Montpellier, France
- Institut de Recherche en Infectiologie de Montpellier, University of Montpellier, Montpellier, France
| | - Mounia Lagha
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, Montpellier, France
| | - Ruth Lehmann
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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3
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Earwood R, Ninomiya H, Wang H, Shimada IS, Stroud M, Perez D, Uuganbayar U, Yamada C, Akiyama-Miyoshi T, Stefanovic B, Kato Y. The binding of LARP6 and DNAAF6 in biomolecular condensates influences ciliogenesis of multiciliated cells. J Biol Chem 2024; 300:107373. [PMID: 38762183 PMCID: PMC11208920 DOI: 10.1016/j.jbc.2024.107373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/19/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024] Open
Abstract
Motile cilia on the cell surface produce fluid flows in the body and abnormalities in motile cilia cause primary ciliary dyskinesia. Dynein axonemal assembly factor 6 (DNAAF6), a causative gene of primary ciliary dyskinesia, was isolated as an interacting protein with La ribonucleoprotein 6 (LARP6) that regulates ciliogenesis in multiciliated cells (MCCs). In MCCs of Xenopus embryos, LARP6 and DNAAF6 were colocalized in biomolecular condensates termed dynein axonemal particles and synergized to control ciliogenesis. Moreover, tubulin alpha 1c-like mRNA encoding α-tubulin protein, that is a major component of ciliary axoneme, was identified as a target mRNA regulated by binding LARP6. While DNAAF6 was necessary for high α-tubulin protein expression near the apical side of Xenopus MCCs during ciliogenesis, its mutant, which abolishes binding with LARP6, was unable to restore the expression of α-tubulin protein near the apical side of MCCs in Xenopus DNAAF6 morphant. These results indicated that the binding of LARP6 and DNAAF6 in dynein axonemal particles regulates highly expressed α-tubulin protein near the apical side of Xenopus MCCs during ciliogenesis.
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Affiliation(s)
- Ryan Earwood
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Hiromasa Ninomiya
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Hao Wang
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Issei S Shimada
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Mia Stroud
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Diana Perez
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Udval Uuganbayar
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Chisato Yamada
- Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
| | - Toru Akiyama-Miyoshi
- Pathogenic Microbe Laboratory, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Branko Stefanovic
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA.
| | - Yoichi Kato
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA; Department of Cell Biology, Nagoya City University, Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
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4
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Rangone H, Bond L, Weil TT, Glover DM. Greatwall-Endos-PP2A/B55 Twins network regulates translation and stability of maternal transcripts in the Drosophila oocyte-to-embryo transition. Open Biol 2024; 14:240065. [PMID: 38896085 DOI: 10.1098/rsob.240065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/24/2024] [Indexed: 06/21/2024] Open
Abstract
The transition from oocyte to embryo requires translation of maternally provided transcripts that in Drosophila is activated by Pan Gu kinase to release a rapid succession of 13 mitotic cycles. Mitotic entry is promoted by several protein kinases that include Greatwall/Mastl, whose Endosulfine substrates antagonize Protein Phosphatase 2A (PP2A), facilitating mitotic Cyclin-dependent kinase 1/Cyclin B kinase activity. Here we show that hyperactive greatwallScant can not only be suppressed by mutants in its Endos substrate but also by mutants in Pan Gu kinase subunits. Conversely, mutants in me31B or trailer hitch, which encode a complex that represses hundreds of maternal mRNAs, enhance greatwallScant . Me31B and Trailer Hitch proteins, known substrates of Pan Gu kinase, copurify with Endos. This echoes findings that budding yeast Dhh1, orthologue of Me31B, associates with Igo1/2, orthologues of Endos and substrates of the Rim15, orthologue of Greatwall. endos-derived mutant embryos show reduced Me31B and elevated transcripts for the mitotic activators Cyclin B, Polo and Twine/Cdc25. Together, our findings demonstrate a previously unappreciated conservation of the Greatwall-Endosulfine pathway in regulating translational repressors and its interactions with the Pan Gu kinase pathway to regulate translation and/or stability of maternal mRNAs upon egg activation.
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Affiliation(s)
- Hélène Rangone
- Department of Genetics, University of Cambridge, Downing Street , Cambridge, UK
| | - Laura Bond
- Department of Genetics, University of Cambridge, Downing Street , Cambridge, UK
| | - Timothy T Weil
- Department of Zoology, University of Cambridge, Downing Street , Cambridge, UK
| | - David M Glover
- Department of Genetics, University of Cambridge, Downing Street , Cambridge, UK
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd , Pasadena, CA 91125, USA
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5
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Gao M. Me31B: a key repressor in germline regulation and beyond. Biosci Rep 2024; 44:BSR20231769. [PMID: 38606619 PMCID: PMC11065648 DOI: 10.1042/bsr20231769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/13/2024] Open
Abstract
Maternally Expressed at 31B (Me31B), an evolutionarily conserved ATP-dependent RNA helicase, plays an important role in the development of the germline across diverse animal species. Its cellular functionality has been posited as a translational repressor, participating in various RNA metabolism pathways to intricately regulate the spatiotemporal expression of RNAs. Despite its evident significance, the precise role and mechanistic underpinnings of Me31B remain insufficiently understood. This article endeavors to comprehensively review historic and recent research on Me31B, distill the major findings, discern generalizable patterns in Me31B's functions across different research contexts, and provide insights into its fundamental role and mechanism of action. The primary focus of this article centers on elucidating the role of Drosophila Me31B within the germline, while concurrently delving into pertinent research on its orthologs within other species and cellular systems.
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Affiliation(s)
- Ming Gao
- Biology Department, Indiana University Northwest, Gary, IN, U.S.A
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6
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Su J, Xu X, Cseke LJ, Whittier S, Zhou R, Zhang Z, Dietz Z, Singh K, Yang B, Chen SY, Picking W, Zou X, Gassmann W. Cell-specific polymerization-driven biomolecular condensate formation fine-tunes root tissue morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.02.587845. [PMID: 38617336 PMCID: PMC11014531 DOI: 10.1101/2024.04.02.587845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Formation of biomolecular condensates can be driven by weak multivalent interactions and emergent polymerization. However, the mechanism of polymerization-mediated condensate formation is less studied. We found lateral root cap cell (LRC)-specific SUPPRESSOR OF RPS4-RLD1 (SRFR1) condensates fine-tune primary root development. Polymerization of the SRFR1 N-terminal domain is required for both LRC condensate formation and optimal root growth. Surprisingly, the first intrinsically disordered region (IDR1) of SRFR1 can be functionally substituted by a specific group of intrinsically disordered proteins known as dehydrins. This finding facilitated the identification of functional segments in the IDR1 of SRFR1, a generalizable strategy to decode unknown IDRs. With this functional information we further improved root growth by modifying the SRFR1 condensation module, providing a strategy to improve plant growth and resilience.
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7
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Cassani M, Seydoux G. P-body-like condensates in the germline. Semin Cell Dev Biol 2024; 157:24-32. [PMID: 37407370 PMCID: PMC10761593 DOI: 10.1016/j.semcdb.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
P-bodies are cytoplasmic condensates that accumulate low-translation mRNAs for temporary storage before translation or degradation. P-bodies have been best characterized in yeast and mammalian tissue culture cells. We describe here related condensates in the germline of animal models. Germline P-bodies have been reported at all stages of germline development from primordial germ cells to gametes. The activity of the universal germ cell fate regulator, Nanos, is linked to the mRNA decay function of P-bodies, and spatially-regulated condensation of P-body like condensates in embryos is required to localize mRNA regulators to primordial germ cells. In most cases, however, it is not known whether P-bodies represent functional compartments or non-functional condensation by-products that arise when ribonucleoprotein complexes saturate the cytoplasm. We speculate that the ubiquity of P-body-like condensates in germ cells reflects the strong reliance of the germline on cytoplasmic, rather than nuclear, mechanisms of gene regulation.
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Affiliation(s)
- Madeline Cassani
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Geraldine Seydoux
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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8
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Holehouse AS, Kragelund BB. The molecular basis for cellular function of intrinsically disordered protein regions. Nat Rev Mol Cell Biol 2024; 25:187-211. [PMID: 37957331 DOI: 10.1038/s41580-023-00673-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2023] [Indexed: 11/15/2023]
Abstract
Intrinsically disordered protein regions exist in a collection of dynamic interconverting conformations that lack a stable 3D structure. These regions are structurally heterogeneous, ubiquitous and found across all kingdoms of life. Despite the absence of a defined 3D structure, disordered regions are essential for cellular processes ranging from transcriptional control and cell signalling to subcellular organization. Through their conformational malleability and adaptability, disordered regions extend the repertoire of macromolecular interactions and are readily tunable by their structural and chemical context, making them ideal responders to regulatory cues. Recent work has led to major advances in understanding the link between protein sequence and conformational behaviour in disordered regions, yet the link between sequence and molecular function is less well defined. Here we consider the biochemical and biophysical foundations that underlie how and why disordered regions can engage in productive cellular functions, provide examples of emerging concepts and discuss how protein disorder contributes to intracellular information processing and regulation of cellular function.
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Affiliation(s)
- Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, USA.
- Center for Biomolecular Condensates, Washington University in St Louis, St Louis, MO, USA.
| | - Birthe B Kragelund
- REPIN, Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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9
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Lu F, Park BJ, Fujiwara R, Wilusz JE, Gilmour DS, Lehmann R, Lionnet T. Integrator-mediated clustering of poised RNA polymerase II synchronizes histone transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.07.561364. [PMID: 37873455 PMCID: PMC10592978 DOI: 10.1101/2023.10.07.561364] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Numerous components of the transcription machinery, including RNA polymerase II (Pol II), accumulate in regions of high local concentration known as clusters, which are thought to facilitate transcription. Using the histone locus of Drosophila nurse cells as a model, we find that Pol II forms long-lived, transcriptionally poised clusters distinct from liquid droplets, which contain unbound and paused Pol II. Depletion of the Integrator complex endonuclease module, but not its phosphatase module or Pol II pausing factors disperses these Pol II clusters. Consequently, histone transcription fails to reach peak levels during S-phase and aberrantly continues throughout the cell cycle. We propose that Pol II clustering is a regulatory step occurring near promoters that limits rapid gene activation to defined times. One Sentence Summary Using the Drosophila histone locus as a model, we show that clustered RNA polymerase II is poised for synchronous activation.
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10
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Crabtree MD, Holland J, Pillai AS, Kompella PS, Babl L, Turner NN, Eaton JT, Hochberg GKA, Aarts DGAL, Redfield C, Baldwin AJ, Nott TJ. Ion binding with charge inversion combined with screening modulates DEAD box helicase phase transitions. Cell Rep 2023; 42:113375. [PMID: 37980572 PMCID: PMC10935546 DOI: 10.1016/j.celrep.2023.113375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 07/14/2023] [Accepted: 10/18/2023] [Indexed: 11/21/2023] Open
Abstract
Membraneless organelles, or biomolecular condensates, enable cells to compartmentalize material and processes into unique biochemical environments. While specific, attractive molecular interactions are known to stabilize biomolecular condensates, repulsive interactions, and the balance between these opposing forces, are largely unexplored. Here, we demonstrate that repulsive and attractive electrostatic interactions regulate condensate stability, internal mobility, interfaces, and selective partitioning of molecules both in vitro and in cells. We find that signaling ions, such as calcium, alter repulsions between model Ddx3 and Ddx4 condensate proteins by directly binding to negatively charged amino acid sidechains and effectively inverting their charge, in a manner fundamentally dissimilar to electrostatic screening. Using a polymerization model combined with generalized stickers and spacers, we accurately quantify and predict condensate stability over a wide range of pH, salt concentrations, and amino acid sequences. Our model provides a general quantitative treatment for understanding how charge and ions reversibly control condensate stability.
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Affiliation(s)
- Michael D Crabtree
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Jack Holland
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Arvind S Pillai
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Purnima S Kompella
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Leon Babl
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Noah N Turner
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - James T Eaton
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK; Kavli Insititute of Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, Sherrington Rd, Oxford, OX1 3QU, UK
| | - Georg K A Hochberg
- Department of Chemistry, Philipps University Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany; Center for Synthetic Microbiology, Philipps University Marburg, Karl-von-Frisch-Straße 14, 35032 Marburg, Germany
| | - Dirk G A L Aarts
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Christina Redfield
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Andrew J Baldwin
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK; Kavli Insititute of Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, Sherrington Rd, Oxford, OX1 3QU, UK.
| | - Timothy J Nott
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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11
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Brothers WR, Ali F, Kajjo S, Fabian MR. The EDC4-XRN1 interaction controls P-body dynamics to link mRNA decapping with decay. EMBO J 2023; 42:e113933. [PMID: 37621215 PMCID: PMC10620763 DOI: 10.15252/embj.2023113933] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/19/2023] [Accepted: 07/22/2023] [Indexed: 08/26/2023] Open
Abstract
Deadenylation-dependent mRNA decapping and decay is the major cytoplasmic mRNA turnover pathway in eukaryotes. Many mRNA decapping and decay factors are associated with each other via protein-protein interaction motifs. For example, the decapping enzyme DCP2 and the 5'-3' exonuclease XRN1 interact with the enhancer of mRNA-decapping protein 4 (EDC4), a large scaffold that has been reported to stimulate mRNA decapping. mRNA decapping and decay factors are also found in processing bodies (P-bodies), evolutionarily conserved ribonucleoprotein granules that are often enriched with mRNAs targeted for decay, yet paradoxically are not required for mRNA decay to occur. Here, we show that disrupting the EDC4-XRN1 interaction or altering their stoichiometry inhibits mRNA decapping, with microRNA-targeted mRNAs being stabilized in a translationally repressed state. Importantly, we demonstrate that this concomitantly leads to larger P-bodies that are responsible for preventing mRNA decapping. Finally, we demonstrate that P-bodies support cell viability and prevent stress granule formation when XRN1 is limiting. Taken together, these data demonstrate that the interaction between XRN1 and EDC4 regulates P-body dynamics to properly coordinate mRNA decapping with 5'-3' decay in human cells.
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Affiliation(s)
- William R Brothers
- Lady Davis Institute for Medical ResearchJewish General HospitalMontrealQCCanada
| | - Farah Ali
- Lady Davis Institute for Medical ResearchJewish General HospitalMontrealQCCanada
| | - Sam Kajjo
- Lady Davis Institute for Medical ResearchJewish General HospitalMontrealQCCanada
| | - Marc R Fabian
- Lady Davis Institute for Medical ResearchJewish General HospitalMontrealQCCanada
- Department of BiochemistryMcGill UniversityMontrealQCCanada
- Department of OncologyMcGill UniversityMontrealQCCanada
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12
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Lin Y, Suyama R, Kawaguchi S, Iki T, Kai T. Tejas functions as a core component in nuage assembly and precursor processing in Drosophila piRNA biogenesis. J Cell Biol 2023; 222:e202303125. [PMID: 37555815 PMCID: PMC10412688 DOI: 10.1083/jcb.202303125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/11/2023] [Accepted: 07/13/2023] [Indexed: 08/10/2023] Open
Abstract
PIWI-interacting RNAs (piRNAs), which protect genome from the attack by transposons, are produced and amplified in membraneless granules called nuage. In Drosophila, PIWI family proteins, Tudor-domain-containing (Tdrd) proteins, and RNA helicases are assembled and form nuage to ensure piRNA production. However, the molecular functions of the Tdrd protein Tejas (Tej) in piRNA biogenesis remain unknown. Here, we conduct a detailed analysis of the subcellular localization of fluorescently tagged nuage proteins and behavior of piRNA precursors. Our results demonstrate that Tej functions as a core component that recruits Vasa (Vas) and Spindle-E (Spn-E) into nuage granules through distinct motifs, thereby assembling nuage and engaging precursors for further processing. Our study also reveals that the low-complexity region of Tej regulates the mobility of Vas. Based on these results, we propose that Tej plays a pivotal role in piRNA precursor processing by assembling Vas and Spn-E into nuage and modulating the mobility of nuage components.
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Affiliation(s)
- Yuxuan Lin
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Ritsuko Suyama
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | | | - Taichiro Iki
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Toshie Kai
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
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13
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Wilby EL, Weil TT. Relating the Biogenesis and Function of P Bodies in Drosophila to Human Disease. Genes (Basel) 2023; 14:1675. [PMID: 37761815 PMCID: PMC10530015 DOI: 10.3390/genes14091675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/29/2023] Open
Abstract
Drosophila has been a premier model organism for over a century and many discoveries in flies have furthered our understanding of human disease. Flies have been successfully applied to many aspects of health-based research spanning from behavioural addiction, to dysplasia, to RNA dysregulation and protein misfolding. Recently, Drosophila tissues have been used to study biomolecular condensates and their role in multicellular systems. Identified in a wide range of plant and animal species, biomolecular condensates are dynamic, non-membrane-bound sub-compartments that have been observed and characterised in the cytoplasm and nuclei of many cell types. Condensate biology has exciting research prospects because of their diverse roles within cells, links to disease, and potential for therapeutics. In this review, we will discuss processing bodies (P bodies), a conserved biomolecular condensate, with a particular interest in how Drosophila can be applied to advance our understanding of condensate biogenesis and their role in disease.
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Affiliation(s)
| | - Timothy T. Weil
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK;
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14
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Lalmansingh JM, Keeley AT, Ruff KM, Pappu RV, Holehouse AS. SOURSOP: A Python Package for the Analysis of Simulations of Intrinsically Disordered Proteins. J Chem Theory Comput 2023; 19:5609-5620. [PMID: 37463458 PMCID: PMC11188088 DOI: 10.1021/acs.jctc.3c00190] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Conformational heterogeneity is a defining hallmark of intrinsically disordered proteins and protein regions (IDRs). The functions of IDRs and the emergent cellular phenotypes they control are associated with sequence-specific conformational ensembles. Simulations of conformational ensembles that are based on atomistic and coarse-grained models are routinely used to uncover the sequence-specific interactions that may contribute to IDR functions. These simulations are performed either independently or in conjunction with data from experiments. Functionally relevant features of IDRs can span a range of length scales. Extracting these features requires analysis routines that quantify a range of properties. Here, we describe a new analysis suite simulation analysis of unfolded regions of proteins (SOURSOP), an object-oriented and open-source toolkit designed for the analysis of simulated conformational ensembles of IDRs. SOURSOP implements several analysis routines motivated by principles in polymer physics, offering a unique collection of simple-to-use functions to characterize IDR ensembles. As an extendable framework, SOURSOP supports the development and implementation of new analysis routines that can be easily packaged and shared.
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Affiliation(s)
- Jared M. Lalmansingh
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alex T. Keeley
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana-Champaign, IL 61801, USA
| | - Kiersten M. Ruff
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Alex S. Holehouse
- Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
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15
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Kara E, McCambridge A, Proffer M, Dilts C, Pumnea B, Eshak J, Smith KA, Fielder I, Doyle DA, Ortega BM, Mukatash Y, Malik N, Mohammed AR, Govani D, Niepielko MG, Gao M. Mutational analysis of the functional motifs of the DEAD-box RNA helicase Me31B/DDX6 in Drosophila germline development. FEBS Lett 2023; 597:1848-1867. [PMID: 37235728 PMCID: PMC10389067 DOI: 10.1002/1873-3468.14668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/24/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023]
Abstract
Me31B/DDX6 is a DEAD-box family RNA helicase playing roles in post-transcriptional RNA regulation in different cell types and species. Despite the known motifs/domains of Me31B, the in vivo functions of the motifs remain unclear. Here, we used the Drosophila germline as a model and used CRISPR to mutate the key Me31B motifs/domains: helicase domain, N-terminal domain, C-terminal domain and FDF-binding motif. Then, we performed screening characterization on the mutants and report the effects of the mutations on the Drosophila germline, on processes such as fertility, oogenesis, embryo patterning, germline mRNA regulation and Me31B protein expression. The study indicates that the Me31B motifs contribute different functions to the protein and are needed for proper germline development, providing insights into the in vivo working mechanism of the helicase.
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Affiliation(s)
- Evan Kara
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | - Megan Proffer
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Carol Dilts
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Brooke Pumnea
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - John Eshak
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Korey A. Smith
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Isaac Fielder
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Dominique A. Doyle
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
| | - Bianca M. Ortega
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
| | - Yousif Mukatash
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Noor Malik
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | - Deep Govani
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Matthew G. Niepielko
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
- Biology Department, Kean University, Union, NJ, USA
| | - Ming Gao
- Biology Department, Indiana University Northwest, Gary, IN, USA
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16
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Hirose T, Ninomiya K, Nakagawa S, Yamazaki T. A guide to membraneless organelles and their various roles in gene regulation. Nat Rev Mol Cell Biol 2023; 24:288-304. [PMID: 36424481 DOI: 10.1038/s41580-022-00558-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2022] [Indexed: 11/25/2022]
Abstract
Membraneless organelles (MLOs) are detected in cells as dots of mesoscopic size. By undergoing phase separation into a liquid-like or gel-like phase, MLOs contribute to intracellular compartmentalization of specific biological functions. In eukaryotes, dozens of MLOs have been identified, including the nucleolus, Cajal bodies, nuclear speckles, paraspeckles, promyelocytic leukaemia protein (PML) nuclear bodies, nuclear stress bodies, processing bodies (P bodies) and stress granules. MLOs contain specific proteins, of which many possess intrinsically disordered regions (IDRs), and nucleic acids, mainly RNA. Many MLOs contribute to gene regulation by different mechanisms. Through sequestration of specific factors, MLOs promote biochemical reactions by simultaneously concentrating substrates and enzymes, and/or suppressing the activity of the sequestered factors elsewhere in the cell. Other MLOs construct inter-chromosomal hubs by associating with multiple loci, thereby contributing to the biogenesis of macromolecular machineries essential for gene expression, such as ribosomes and spliceosomes. The organization of many MLOs includes layers, which might have different biophysical properties and functions. MLOs are functionally interconnected and are involved in various diseases, prompting the emergence of therapeutics targeting them. In this Review, we introduce MLOs that are relevant to gene regulation and discuss their assembly, internal structure, gene-regulatory roles in transcription, RNA processing and translation, particularly in stress conditions, and their disease relevance.
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Affiliation(s)
- Tetsuro Hirose
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Suita, Japan.
| | - Kensuke Ninomiya
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Shinichi Nakagawa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Tomohiro Yamazaki
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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17
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Che X, Wu J, Liu H, Su J, Chen X. Cellular liquid-liquid phase separation: Concept, functions, regulations, and detections. J Cell Physiol 2023; 238:847-865. [PMID: 36870067 DOI: 10.1002/jcp.30980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/05/2022] [Accepted: 02/08/2023] [Indexed: 03/06/2023]
Abstract
Liquid-liquid phase separation is a multicomponent system separated into phases with different compositions and structures. It has been identified and explored in organisms after being introduced from the thermodynamic field. Condensate, the product of phase separation, exists in different scales of cellular structures, such as nucleolus, stress granules, and other organelles in nuclei or cytoplasm. And also play critical roles in different cellular behaviors. Here, we review the concept, thermodynamical and biochemical principles of phase separation. We summarized the main functions including the adjustment of biochemical reaction rates, the regulation of macromolecule folding state, subcellular structural support, the mediation of subcellular location, and intimately linked to different kinds of diseases, such as cancer and neurodegeneration. Advanced detection methods to investigate phase separation are collected and analyzed. We conclude with the discussion of anxiety of phase separation, and thought about how progress can be made to develop precise detection methods and disclose the potential application of condensates.
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Affiliation(s)
- Xuanlin Che
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
| | - Jiajun Wu
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Hua Liu
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Juan Su
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
| | - Xiang Chen
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
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18
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Lalmansingh JM, Keeley AT, Ruff KM, Pappu RV, Holehouse AS. SOURSOP: A Python package for the analysis of simulations of intrinsically disordered proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.16.528879. [PMID: 36824878 PMCID: PMC9949127 DOI: 10.1101/2023.02.16.528879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Conformational heterogeneity is a defining hallmark of intrinsically disordered proteins and protein regions (IDRs). The functions of IDRs and the emergent cellular phenotypes they control are associated with sequence-specific conformational ensembles. Simulations of conformational ensembles that are based on atomistic and coarse-grained models are routinely used to uncover the sequence-specific interactions that may contribute to IDR functions. These simulations are performed either independently or in conjunction with data from experiments. Functionally relevant features of IDRs can span a range of length scales. Extracting these features requires analysis routines that quantify a range of properties. Here, we describe a new analysis suite SOURSOP, an object-oriented and open-source toolkit designed for the analysis of simulated conformational ensembles of IDRs. SOURSOP implements several analysis routines motivated by principles in polymer physics, offering a unique collection of simple-to-use functions to characterize IDR ensembles. As an extendable framework, SOURSOP supports the development and implementation of new analysis routines that can be easily packaged and shared.
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19
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Forbes Beadle L, Love JC, Shapovalova Y, Artemev A, Rattray M, Ashe HL. Combined modelling of mRNA decay dynamics and single-molecule imaging in the Drosophila embryo uncovers a role for P-bodies in 5' to 3' degradation. PLoS Biol 2023; 21:e3001956. [PMID: 36649329 PMCID: PMC9882958 DOI: 10.1371/journal.pbio.3001956] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 01/27/2023] [Accepted: 12/13/2022] [Indexed: 01/18/2023] Open
Abstract
Regulation of mRNA degradation is critical for a diverse array of cellular processes and developmental cell fate decisions. Many methods for determining mRNA half-lives rely on transcriptional inhibition or metabolic labelling. Here, we use a non-invasive method for estimating half-lives for hundreds of mRNAs in the early Drosophila embryo. This approach uses the intronic and exonic reads from a total RNA-seq time series and Gaussian process regression to model the dynamics of premature and mature mRNAs. We show how regulation of mRNA stability is used to establish a range of mature mRNA dynamics during embryogenesis, despite shared transcription profiles. Using single-molecule imaging, we provide evidence that, for the mRNAs tested, there is a correlation between short half-life and mRNA association with P-bodies. Moreover, we detect an enrichment of mRNA 3' ends in P-bodies in the early embryo, consistent with 5' to 3' degradation occurring in P-bodies for at least a subset of mRNAs. We discuss our findings in relation to recently published data suggesting that the primary function of P-bodies in other biological contexts is mRNA storage.
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Affiliation(s)
- Lauren Forbes Beadle
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jennifer C. Love
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Yuliya Shapovalova
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Artem Artemev
- Department of Computing, Imperial College London, London, United Kingdom
| | - Magnus Rattray
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (MR); (HLA)
| | - Hilary L. Ashe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (MR); (HLA)
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20
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Bayer LV, Milano S, Formel SK, Kaur H, Ravichandran R, Cambeiro JA, Slinko L, Catrina IE, Bratu DP. Cup is essential for oskar mRNA translational repression during early Drosophila oogenesis. RNA Biol 2023; 20:573-587. [PMID: 37553798 PMCID: PMC10413924 DOI: 10.1080/15476286.2023.2242650] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/27/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023] Open
Abstract
Study of the timing and location for mRNA translation across model systems has begun to shed light on molecular events fundamental to such processes as intercellular communication, morphogenesis, and body pattern formation. In D. melanogaster, the posterior mRNA determinant, oskar, is transcribed maternally but translated only when properly localized at the oocyte's posterior cortex. Two effector proteins, Bruno1 and Cup, mediate steps of oskar mRNA regulation. The current model in the field identifies Bruno1 as necessary for Cup's recruitment to oskar mRNA and indispensable for oskar's translational repression. We now report that this Bruno1-Cup interaction leads to precise oskar mRNA regulation during early oogenesis and, importantly, the two proteins mutually influence each other's mRNA expression and protein distribution in the egg chamber. We show that these factors stably associate with oskar mRNA in vivo. Cup associates with oskar mRNA without Bruno1, while surprisingly Bruno1's stable association with oskar mRNA depends on Cup. We demonstrate that the essential factor for oskar mRNA repression in early oogenesis is Cup, not Bruno1. Furthermore, we find that Cup is a key P-body component that maintains functional P-body morphology during oogenesis and is necessary for oskar mRNA's association with P-bodies. Therefore, Cup drives the translational repression and stability of oskar mRNA. These experimental results point to a regulatory feedback loop between Bruno 1 and Cup in early oogenesis that appears crucial for oskar mRNA to reach the posterior pole and its expression in the egg chamber for accurate embryo development.
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Affiliation(s)
- Livia V. Bayer
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
- Program in Molecular, Cellular, and Developmental Biology, the Graduate Center, City University of New York, New York, NY, USA
| | - Samantha Milano
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
- Program in Molecular, Cellular, and Developmental Biology, the Graduate Center, City University of New York, New York, NY, USA
| | - Stephen K. Formel
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
| | - Harpreet Kaur
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
| | - Rishi Ravichandran
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
| | - Juan A. Cambeiro
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
| | - Lizaveta Slinko
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
| | - Irina E. Catrina
- Department of Chemistry and Biochemistry, Yeshiva University, New York, NY, USA
| | - Diana P. Bratu
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY, USA
- Program in Molecular, Cellular, and Developmental Biology, the Graduate Center, City University of New York, New York, NY, USA
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21
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Wu C, Holehouse AS, Leung DW, Amarasinghe GK, Dutch RE. Liquid Phase Partitioning in Virus Replication: Observations and Opportunities. Annu Rev Virol 2022; 9:285-306. [PMID: 35709511 DOI: 10.1146/annurev-virology-093020-013659] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viruses frequently carry out replication in specialized compartments within cells. The effect of these structures on virus replication is poorly understood. Recent research supports phase separation as a foundational principle for organization of cellular components with the potential to influence viral replication. In this review, phase separation is described in the context of formation of viral replication centers, with an emphasis on the nonsegmented negative-strand RNA viruses. Consideration is given to the interplay between phase separation and the critical processes of viral transcription and genome replication, and the role of these regions in pathogen-host interactions is discussed. Finally, critical questions that must be addressed to fully understand how phase separation influences viral replication and the viral life cycle are presented, along with information about new approaches that could be used to make important breakthroughs in this emerging field.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Science and Engineering Living Systems, Washington University, St. Louis, Missouri, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA;
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22
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Brothers WR, Fakim H, Kajjo S, Fabian MR. P-bodies directly regulate MARF1-mediated mRNA decay in human cells. Nucleic Acids Res 2022; 50:7623-7636. [PMID: 35801873 PMCID: PMC9303261 DOI: 10.1093/nar/gkac557] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/10/2022] [Accepted: 06/15/2022] [Indexed: 11/12/2022] Open
Abstract
Processing bodies (P-bodies) are ribonucleoprotein granules that contain mRNAs, RNA-binding proteins and effectors of mRNA turnover. While P-bodies have been reported to contain translationally repressed mRNAs, a causative role for P-bodies in regulating mRNA decay has yet to be established. Enhancer of decapping protein 4 (EDC4) is a core P-body component that interacts with multiple mRNA decay factors, including the mRNA decapping (DCP2) and decay (XRN1) enzymes. EDC4 also associates with the RNA endonuclease MARF1, an interaction that antagonizes the decay of MARF1-targeted mRNAs. How EDC4 interacts with MARF1 and how it represses MARF1 activity is unclear. In this study, we show that human MARF1 and XRN1 interact with EDC4 using analogous conserved short linear motifs in a mutually exclusive manner. While the EDC4–MARF1 interaction is required for EDC4 to inhibit MARF1 activity, our data indicate that the interaction with EDC4 alone is not sufficient. Importantly, we show that P-body architecture plays a critical role in antagonizing MARF1-mediated mRNA decay. Taken together, our study suggests that P-bodies can directly regulate mRNA turnover by sequestering an mRNA decay enzyme and preventing it from interfacing with and degrading targeted mRNAs.
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Affiliation(s)
- William R Brothers
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Hana Fakim
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Sam Kajjo
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Marc R Fabian
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada.,Department of Biochemistry, McGill University Montreal, Quebec, H3A 1A3, Canada.,Gerald Bronfman Department of Oncology, McGill University Montreal, Quebec, H3A 1G5, Canada
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23
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Linsenmeier M, Hondele M, Grigolato F, Secchi E, Weis K, Arosio P. Dynamic arrest and aging of biomolecular condensates are modulated by low-complexity domains, RNA and biochemical activity. Nat Commun 2022; 13:3030. [PMID: 35641495 PMCID: PMC9156751 DOI: 10.1038/s41467-022-30521-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/27/2022] [Indexed: 11/18/2022] Open
Abstract
Biomolecular condensates require suitable control of material properties for their function. Here we apply Differential Dynamic Microscopy (DDM) to probe the material properties of an in vitro model of processing bodies consisting of out-of-equilibrium condensates formed by the DEAD-box ATPase Dhh1 in the presence of ATP and RNA. By applying this single-droplet technique we show that condensates within the same population exhibit a distribution of material properties, which are regulated on several levels. Removal of the low-complexity domains (LCDs) of the protein decreases the fluidity of the condensates. Structured RNA leads to a larger fraction of dynamically arrested condensates with respect to unstructured polyuridylic acid (polyU). Promotion of the enzymatic ATPase activity of Dhh1 reduces aging of the condensates and the formation of arrested structures, indicating that biochemical activity and material turnover can maintain fluid-like properties over time.
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Affiliation(s)
- Miriam Linsenmeier
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland
| | - Maria Hondele
- Department of Biology, Institute for Biochemistry, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland
- Biozentrum, Center for Molecular Life Sciences, University of Basel, 4056, Basel, Switzerland
| | - Fulvio Grigolato
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland
| | - Karsten Weis
- Department of Biology, Institute for Biochemistry, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland.
| | - Paolo Arosio
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, 8093, Zurich, Switzerland.
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