1
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Engelfriet ML, Guo Y, Arnold A, Valen E, Ciosk R. Reprograming gene expression in 'hibernating' C. elegans involves the IRE-1/XBP-1 pathway. eLife 2025; 13:RP101186. [PMID: 40326887 PMCID: PMC12055002 DOI: 10.7554/elife.101186] [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] [Indexed: 05/07/2025] Open
Abstract
In nature, many animals respond to cold by entering hibernation, while in clinical settings, controlled cooling is used in transplantation and emergency medicine. However, the molecular mechanisms that enable cells to survive severe cold are still not fully understood. One key aspect of cold adaptation is the global downregulation of protein synthesis. Studying it in the nematode Caenorhabditis elegans, we find that the translation of most mRNAs continues in the cold, albeit at a slower rate, and propose that cold-specific gene expression is regulated primarily at the transcription level. Supporting this idea, we found that the transcription of certain cold-induced genes is linked to the activation of unfolded protein response (UPR) through the conserved IRE-1/XBP-1 signaling pathway. Our findings suggest that this pathway is triggered by cold-induced perturbations in proteins and lipids within the endoplasmic reticulum, and that its activation is beneficial for cold survival.
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Affiliation(s)
- Melanie Lianne Engelfriet
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOsloNorway
| | - Yanwu Guo
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOsloNorway
| | - Andreas Arnold
- Division of Molecular Neuroscience, Department of Biomedicine, University of BaselBaselSwitzerland
- University Psychiatric Clinics, University of BaselBaselSwitzerland
| | - Eivind Valen
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOsloNorway
| | - Rafal Ciosk
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOsloNorway
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2
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Erdmann EA, Forbes M, Becker M, Perez S, Hundley HA. ADR-2 regulates fertility and oocyte fate in Caenorhabditis elegans. Genetics 2024; 228:iyae114. [PMID: 39028799 PMCID: PMC11457940 DOI: 10.1093/genetics/iyae114] [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: 05/24/2024] [Revised: 05/24/2024] [Accepted: 07/09/2024] [Indexed: 07/21/2024] Open
Abstract
RNA-binding proteins (RBPs) play essential roles in coordinating germline gene expression and development in all organisms. Here, we report that loss of ADR-2, a member of the adenosine deaminase acting on RNA family of RBPs and the sole adenosine-to-inosine RNA-editing enzyme in Caenorhabditis elegans, can improve fertility in multiple genetic backgrounds. First, we show that loss of RNA editing by ADR-2 restores normal embryo production to subfertile animals that transgenically express a vitellogenin (yolk protein) fusion to green fluorescent protein. Using this phenotype, a high-throughput screen was designed to identify RBPs that when depleted yield synthetic phenotypes with loss of adr-2. The screen uncovered a genetic interaction between ADR-2 and SQD-1, a member of the heterogeneous nuclear ribonucleoprotein family of RBPs. Microscopy, reproductive assays, and high-throughput sequencing reveal that sqd-1 is essential for the onset of oogenesis and oogenic gene expression in young adult animals and that loss of adr-2 can counteract the effects of loss of sqd-1 on gene expression and rescue the switch from spermatogenesis to oogenesis. Together, these data demonstrate that ADR-2 can contribute to the suppression of fertility and suggest novel roles for both RNA editing-dependent and RNA editing-independent mechanisms in regulating embryogenesis.
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Affiliation(s)
- Emily A Erdmann
- Genome, Cell and Developmental Biology Graduate Program, Indiana University, Bloomington, IN 47405, USA
| | - Melanie Forbes
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Margaret Becker
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington IN 47405, USA
| | - Sarina Perez
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Heather A Hundley
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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3
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Jones M, Norman M, Tiet AM, Lee J, Lee MH. C. elegans Germline as Three Distinct Tumor Models. BIOLOGY 2024; 13:425. [PMID: 38927305 PMCID: PMC11200432 DOI: 10.3390/biology13060425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024]
Abstract
Tumor cells display abnormal growth and division, avoiding the natural process of cell death. These cells can be benign (non-cancerous growth) or malignant (cancerous growth). Over the past few decades, numerous in vitro or in vivo tumor models have been employed to understand the molecular mechanisms associated with tumorigenesis in diverse regards. However, our comprehension of how non-tumor cells transform into tumor cells at molecular and cellular levels remains incomplete. The nematode C. elegans has emerged as an excellent model organism for exploring various phenomena, including tumorigenesis. Although C. elegans does not naturally develop cancer, it serves as a valuable platform for identifying oncogenes and the underlying mechanisms within a live organism. In this review, we describe three distinct germline tumor models in C. elegans, highlighting their associated mechanisms and related regulators: (1) ectopic proliferation due to aberrant activation of GLP-1/Notch signaling, (2) meiotic entry failure resulting from the loss of GLD-1/STAR RNA-binding protein, (3) spermatogenic dedifferentiation caused by the loss of PUF-8/PUF RNA-binding protein. Each model requires the mutations of specific genes (glp-1, gld-1, and puf-8) and operates through distinct molecular mechanisms. Despite these differences in the origins of tumorigenesis, the internal regulatory networks within each tumor model display shared features. Given the conservation of many of the regulators implicated in C. elegans tumorigenesis, it is proposed that these unique models hold significant potential for enhancing our comprehension of the broader control mechanisms governing tumorigenesis.
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Affiliation(s)
- Mariah Jones
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
| | - Mina Norman
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
| | - Alex Minh Tiet
- Neuroscience Program, East Carolina University, Greenville, NC 27858, USA;
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Jiwoo Lee
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Myon Hee Lee
- Division of Hematology/Oncology, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA; (M.J.); (M.N.)
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
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4
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Erdmann EA, Forbes M, Becker M, Perez S, Hundley HA. ADR-2 regulates fertility and oocyte fate in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.01.565157. [PMID: 37961348 PMCID: PMC10635048 DOI: 10.1101/2023.11.01.565157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
RNA binding proteins play essential roles in coordinating germline gene expression and development in all organisms. Here, we report that loss of ADR-2, a member of the Adenosine DeAminase acting on RNA (ADAR) family of RNA binding proteins and the sole adenosine-to-inosine RNA editing enzyme in C. elegans, can improve fertility in multiple genetic backgrounds. First, we show that loss of RNA editing by ADR-2 restores normal embryo production to subfertile animals that transgenically express a vitellogenin (yolk protein) fusion to green fluorescent protein. Using this phenotype, a high-throughput screen was designed to identify RNA binding proteins that when depleted yield synthetic phenotypes with loss of adr-2. The screen uncovered a genetic interaction between ADR-2 and SQD-1, a member of the heterogenous nuclear ribonucleoprotein (hnRNP) family of RNA binding proteins. Microscopy, reproductive assays, and high-throughput sequencing reveal that sqd-1 is essential for the onset of oogenesis and oogenic gene expression in young adult animals, and that loss of adr-2 can counteract the effects of loss of sqd-1 on gene expression and rescue the switch from spermatogenesis to oogenesis. Together, these data demonstrate that ADR-2 can contribute to the suppression of fertility and suggest novel roles for both RNA editing-dependent and independent mechanisms in regulating embryogenesis.
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Affiliation(s)
- Emily A. Erdmann
- Genome, Cell and Developmental Biology Graduate Program, Indiana University, Bloomington IN, US 47405
| | - Melanie Forbes
- Department of Biology, Indiana University, Bloomington IN, US 47405
| | - Margaret Becker
- Medical Sciences Program, Indiana University School of Medicine-Bloomington, Bloomington IN, US 47405
| | - Sarina Perez
- Department of Biology, Indiana University, Bloomington IN, US 47405
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5
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Engelfriet ML, Małecki JM, Forsberg AF, Falnes PØ, Ciosk R. Characterization of the biochemical activity and tumor-promoting role of the dual protein methyltransferase METL-13/METTL13 in Caenorhabditis elegans. PLoS One 2023; 18:e0287558. [PMID: 37347777 PMCID: PMC10286969 DOI: 10.1371/journal.pone.0287558] [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: 03/13/2023] [Accepted: 06/07/2023] [Indexed: 06/24/2023] Open
Abstract
The methyltransferase-like protein 13 (METTL13) methylates the eukaryotic elongation factor 1 alpha (eEF1A) on two locations: the N-terminal amino group and lysine 55. The absence of this methylation leads to reduced protein synthesis and cell proliferation in human cancer cells. Previous studies showed that METTL13 is dispensable in non-transformed cells, making it potentially interesting for cancer therapy. However, METTL13 has not been examined yet in whole animals. Here, we used the nematode Caenorhabditis elegans as a simple model to assess the functions of METTL13. Using methyltransferase assays and mass spectrometry, we show that the C. elegans METTL13 (METL-13) methylates eEF1A (EEF-1A) in the same way as the human protein. Crucially, the cancer-promoting role of METL-13 is also conserved and depends on the methylation of EEF-1A, like in human cells. At the same time, METL-13 appears dispensable for animal growth, development, and stress responses. This makes C. elegans a convenient whole-animal model for studying METL13-dependent carcinogenesis without the complications of interfering with essential wild-type functions.
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Affiliation(s)
- Melanie L. Engelfriet
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Jędrzej M. Małecki
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Anna F. Forsberg
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Pål Ø. Falnes
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Rafal Ciosk
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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6
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Albarqi MMY, Ryder SP. The role of RNA-binding proteins in orchestrating germline development in Caenorhabditis elegans. Front Cell Dev Biol 2023; 10:1094295. [PMID: 36684428 PMCID: PMC9846511 DOI: 10.3389/fcell.2022.1094295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/19/2022] [Indexed: 01/06/2023] Open
Abstract
RNA passed from parents to progeny controls several aspects of early development. The germline of the free-living nematode Caenorhabditis elegans contains many families of evolutionarily conserved RNA-binding proteins (RBPs) that target the untranslated regions of mRNA transcripts to regulate their translation and stability. In this review, we summarize what is known about the binding specificity of C. elegans germline RNA-binding proteins and the mechanisms of mRNA regulation that contribute to their function. We examine the emerging role of miRNAs in translational regulation of germline and embryo development. We also provide an overview of current technology that can be used to address the gaps in our understanding of RBP regulation of mRNAs. Finally, we present a hypothetical model wherein multiple 3'UTR-mediated regulatory processes contribute to pattern formation in the germline to ensure the proper and timely localization of germline proteins and thus a functional reproductive system.
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7
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Cassani M, Seydoux G. Specialized germline P-bodies are required to specify germ cell fate in Caenorhabditis elegans embryos. Development 2022; 149:dev200920. [PMID: 36196602 PMCID: PMC9686995 DOI: 10.1242/dev.200920] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 09/06/2022] [Indexed: 07/30/2023]
Abstract
In animals with germ plasm, specification of the germline involves 'germ granules', cytoplasmic condensates that enrich maternal transcripts in the germline founder cells. In Caenorhabditis elegans embryos, P granules enrich maternal transcripts, but surprisingly P granules are not essential for germ cell fate specification. Here, we describe a second condensate in the C. elegans germ plasm. Like canonical P-bodies found in somatic cells, 'germline P-bodies' contain regulators of mRNA decapping and deadenylation and, in addition, the intrinsically-disordered proteins MEG-1 and MEG-2 and the TIS11-family RNA-binding protein POS-1. Embryos lacking meg-1 and meg-2 do not stabilize P-body components, misregulate POS-1 targets, mis-specify the germline founder cell and do not develop a germline. Our findings suggest that specification of the germ line involves at least two distinct condensates that independently enrich and regulate maternal mRNAs in the germline founder cells. This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Madeline Cassani
- Howard Hughes Medical Institute and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Geraldine Seydoux
- Howard Hughes Medical Institute 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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Ellis RE. Sex Determination in Nematode Germ Cells. Sex Dev 2022:1-18. [PMID: 35172320 PMCID: PMC9378769 DOI: 10.1159/000520872] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/02/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Animal germ cells differentiate as sperm or as oocytes. These sexual fates are controlled by complex regulatory pathways to ensure that the proper gametes are made at the appropriate times. SUMMARY Nematodes like Caenorhabditis elegans and its close relatives are ideal models for studying how this regulation works, because the XX animals are self-fertile hermaphrodites that produce both sperm and oocytes. In these worms, germ cells use the same signal transduction pathway that functions in somatic cells. This pathway determines the activity of the transcription factor TRA-1, a Gli protein that can repress male genes. However, the pathway is extensively modified in germ cells, largely by the action of translational regulators like the PUF proteins. Many of these modifications play critical roles in allowing the XX hermaphrodites to make sperm in an otherwise female body. Finally, TRA-1 cooperates with chromatin regulators in the germ line to control the activity of fog-1 and fog-3, which are essential for spermatogenesis. FOG-1 and FOG-3 work together to determine germ cell fates by blocking the translation of oogenic transcripts. Key Messages: Although there is great diversity in how germ cell fates are controlled in other animals, many of the key nematode genes are conserved, and the critical role of translational regulators may be universal.
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Affiliation(s)
- Ronald E Ellis
- Department of Molecular Biology, Rowan University SOM, Stratford, New Jersey, USA
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9
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Tocchini C, Rohner M, Guerard L, Ray P, Von Stetina SE, Mango SE. Translation-dependent mRNA localization to Caenorhabditis elegans adherens junctions. Development 2021; 148:273751. [PMID: 34846063 PMCID: PMC8722394 DOI: 10.1242/dev.200027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/08/2021] [Indexed: 11/27/2022]
Abstract
mRNA localization is an evolutionarily widespread phenomenon that can facilitate subcellular protein targeting. Extensive work has focused on mRNA targeting through ‘zip-codes’ within untranslated regions (UTRs), whereas much less is known about translation-dependent cues. Here, we examine mRNA localization in Caenorhabditis elegans embryonic epithelia. From an smFISH-based survey, we identified mRNAs associated with the cell membrane or cortex, and with apical junctions in a stage- and cell type-specific manner. Mutational analyses for one of these transcripts, dlg-1/discs large, revealed that it relied on a translation-dependent process and did not require its 5′ or 3′ UTRs. We suggest a model in which dlg-1 transcripts are co-translationally localized with the nascent protein: first the translating complex goes to the cell membrane using sequences located at the C-terminal/3′ end, and then apically using N-terminal/5′ sequences. These studies identify a translation-based process for mRNA localization within developing epithelia and determine the necessary cis-acting sequences for dlg-1 mRNA targeting. Summary: An smFISH-based survey identifies a subset of mRNAs encoding junctional components that localize at or in proximity to the adherens junction through a translation-dependent mechanism.
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Affiliation(s)
| | - Michèle Rohner
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Poulomi Ray
- Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Susan E Mango
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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10
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Mukherjee N, Mukherjee C. Germ cell ribonucleoprotein granules in different clades of life: From insects to mammals. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1642. [PMID: 33555143 DOI: 10.1002/wrna.1642] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 12/12/2022]
Abstract
Ribonucleoprotein (RNP) granules are no newcomers in biology. Found in all life forms, ranging across taxa, these membrane-less "organelles" have been classified into different categories based on their composition, structure, behavior, function, and localization. Broadly, they can be listed as stress granules (SGs), processing bodies (PBs), neuronal granules (NGs), and germ cell granules (GCGs). Keeping in line with the topic of this review, RNP granules present in the germ cells have been implicated in a wide range of cellular functions including cellular specification, differentiation, proliferation, and so forth. The mechanisms used by them can be diverse and many of them remain partly obscure and active areas of research. GCGs can be of different types in different organisms and at different stages of development, with multiple types coexisting in the same cell. In this review, the different known subcategories of GCGs have been studied with respect to five distinct model organisms, namely, Drosophila, Caenorhabditis elegans, Xenopus, Zebrafish, and mammals. Of them, the cytoplasmic polar granules in Drosophila, P granules in C. elegans, balbiani body in Xenopus and Zebrafish, and chromatoid bodies in mammals have been specifically emphasized upon. A descriptive account of the same has been provided along with insights into our current understanding of their functional significance with respect to cellular events relating to different developmental and reproductive processes. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Export and Localization > RNA Localization RNA in Disease and Development > RNA in Disease.
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11
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Lee CYS, Putnam A, Lu T, He S, Ouyang JPT, Seydoux G. Recruitment of mRNAs to P granules by condensation with intrinsically-disordered proteins. eLife 2020; 9:e52896. [PMID: 31975687 PMCID: PMC7007223 DOI: 10.7554/elife.52896] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 01/23/2020] [Indexed: 12/30/2022] Open
Abstract
RNA granules are protein/RNA condensates. How specific mRNAs are recruited to cytoplasmic RNA granules is not known. Here, we characterize the transcriptome and assembly of P granules, RNA granules in the C. elegans germ plasm. We find that P granules recruit mRNAs by condensation with the disordered protein MEG-3. MEG-3 traps mRNAs into non-dynamic condensates in vitro and binds to ~500 mRNAs in vivo in a sequence-independent manner that favors embryonic mRNAs with low ribosome coverage. Translational stress causes additional mRNAs to localize to P granules and translational activation correlates with P granule exit for two mRNAs coding for germ cell fate regulators. Localization to P granules is not required for translational repression but is required to enrich mRNAs in the germ lineage for robust germline development. Our observations reveal similarities between P granules and stress granules and identify intrinsically-disordered proteins as drivers of RNA condensation during P granule assembly.
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Affiliation(s)
- Chih-Yung S Lee
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
| | - Andrea Putnam
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
| | - Tu Lu
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
| | - ShuaiXin He
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
- Department of Biophysics and Biophysical ChemistryJohns Hopkins University School of MedicineBaltimoreUnited States
| | - John Paul T Ouyang
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
| | - Geraldine Seydoux
- HHMI and Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
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12
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Theil K, Herzog M, Rajewsky N. Post-transcriptional Regulation by 3' UTRs Can Be Masked by Regulatory Elements in 5' UTRs. Cell Rep 2019; 22:3217-3226. [PMID: 29562178 DOI: 10.1016/j.celrep.2018.02.094] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 11/20/2017] [Accepted: 02/23/2018] [Indexed: 11/29/2022] Open
Abstract
In mRNA sequences, 3' UTRs are thought to contain most elements that specifically regulate localization, turnover, and translation. Although high-throughput experiments indicate that many RNA-binding proteins (RBPs) also bind 5' UTRs, much less is known about specific post-transcriptional control exerted by 5' UTRs. GLD-1 is a conserved RBP and a translational repressor with essential roles in Caenorhabditis elegans germ cell development. Previously, we showed that GLD-1 binds highly conserved sites in both 3' and 5' UTRs. Here, by targeted single-copy insertion of transgenes, we systematically tested in vivo functionality of 5' and 3' UTR binding sites individually and in combination. Our data show that sites in 5' UTRs mediate specific and strong translational repression, independent of exact position. Intriguingly, we found that the functionality of 3' UTR sites can be masked by 5' UTR sites and vice versa. We conclude that it is important to study both UTRs simultaneously.
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Affiliation(s)
- Kathrin Theil
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Margareta Herzog
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany.
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13
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Theil K, Imami K, Rajewsky N. Identification of proteins and miRNAs that specifically bind an mRNA in vivo. Nat Commun 2019; 10:4205. [PMID: 31527589 PMCID: PMC6746756 DOI: 10.1038/s41467-019-12050-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/19/2019] [Indexed: 12/26/2022] Open
Abstract
Understanding regulation of an mRNA requires knowledge of its regulators. However, methods for reliable de-novo identification of proteins binding to a particular RNA are scarce and were thus far only successfully applied to abundant noncoding RNAs in cell culture. Here, we present vIPR, an RNA-protein crosslink, RNA pulldown, and shotgun proteomics approach to identify proteins bound to selected mRNAs in C. elegans. Applying vIPR to the germline-specific transcript gld-1 led to enrichment of known and novel interactors. By comparing enrichment upon gld-1 and lin-41 pulldown, we demonstrate that vIPR recovers both common and specific RNA-binding proteins, and we validate DAZ-1 as a specific gld-1 regulator. Finally, combining vIPR with small RNA sequencing, we recover known and biologically important transcript-specific miRNA interactions, and we identify miR-84 as a specific interactor of the gld-1 transcript. We envision that vIPR will provide a platform for investigating RNA in vivo regulation in diverse biological systems.
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Affiliation(s)
- Kathrin Theil
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany.
| | - Koshi Imami
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
- Laboratory of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany.
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14
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Multi-modal regulation of C. elegans hermaphrodite spermatogenesis by the GLD-1-FOG-2 complex. Dev Biol 2018; 446:193-205. [PMID: 30599151 DOI: 10.1016/j.ydbio.2018.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 11/07/2018] [Accepted: 11/12/2018] [Indexed: 01/26/2023]
Abstract
Proper germ cell sex determination in Caenorhabditis nematodes requires a network of RNA-binding proteins (RBPs) and their target mRNAs. In some species, changes in this network enabled limited XX spermatogenesis, and thus self-fertility. In C. elegans, one of these selfing species, the global sex-determining gene tra-2 is regulated in germ cells by a conserved RBP, GLD-1, via the 3' untranslated region (3'UTR) of its transcript. A C. elegans-specific GLD-1 cofactor, FOG-2, is also required for hermaphrodite sperm fate, but how it modifies GLD-1 function is unknown. Germline feminization in gld-1 and fog-2 null mutants has been interpreted as due to cell-autonomous elevation of TRA-2 translation. Consistent with the proposed role of FOG-2 in translational control, the abundance of nearly all GLD-1 target mRNAs (including tra-2) is unchanged in fog-2 mutants. Epitope tagging reveals abundant TRA-2 expression in somatic tissues, but an undetectably low level in wild-type germ cells. Loss of gld-1 function elevates germline TRA-2 expression to detectable levels, but loss of fog-2 function does not. A simple quantitative model of tra-2 activity constrained by these results can successfully sort genotypes into normal or feminized groups. Surprisingly, fog-2 and gld-1 activity enable the sperm fate even when GLD-1 cannot bind to the tra-2 3' UTR. This suggests the GLD-1-FOG-2 complex regulates uncharacterized sites within tra-2, or other mRNA targets. Finally, we quantify the RNA-binding capacities of dominant missense alleles of GLD-1 that act genetically as "hyper-repressors" of tra-2 activity. These variants bind RNA more weakly in vitro than does wild-type GLD-1. These results indicate that gld-1 and fog-2 regulate germline sex via multiple interactions, and that our understanding of the control and evolution of germ cell sex determination in the C. elegans hermaphrodite is far from complete.
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15
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Spike CA, Huelgas-Morales G, Tsukamoto T, Greenstein D. Multiple Mechanisms Inactivate the LIN-41 RNA-Binding Protein To Ensure a Robust Oocyte-to-Embryo Transition in Caenorhabditis elegans. Genetics 2018; 210:1011-1037. [PMID: 30206186 PMCID: PMC6218228 DOI: 10.1534/genetics.118.301421] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/10/2018] [Indexed: 12/23/2022] Open
Abstract
In the nematode Caenorhabditis elegans, the conserved LIN-41 RNA-binding protein is a translational repressor that coordinately controls oocyte growth and meiotic maturation. LIN-41 exerts these effects, at least in part, by preventing the premature activation of the cyclin-dependent kinase CDK-1 Here we investigate the mechanism by which LIN-41 is rapidly eliminated upon the onset of meiotic maturation. Elimination of LIN-41 requires the activities of CDK-1 and multiple SCF (Skp1, Cul1, and F-box protein)-type E3 ubiquitin ligase subunits, including the conserved substrate adaptor protein SEL-10/Fbw7/Cdc4, suggesting that LIN-41 is a target of ubiquitin-mediated protein degradation. Within the LIN-41 protein, two nonoverlapping regions, Deg-A and Deg-B, are individually necessary for LIN-41 degradation; both contain several potential phosphodegron sequences, and at least one of these sequences is required for LIN-41 degradation. Finally, Deg-A and Deg-B are sufficient, in combination, to mediate SEL-10-dependent degradation when transplanted into a different oocyte protein. Although LIN-41 is a potent inhibitor of protein translation and M phase entry, the failure to eliminate LIN-41 from early embryos does not result in the continued translational repression of LIN-41 oocyte messenger RNA targets. Based on these observations, we propose a model for the elimination of LIN-41 by the SEL-10 E3 ubiquitin ligase and suggest that LIN-41 is inactivated before it is degraded. Furthermore, we provide evidence that another RNA-binding protein, the GLD-1 tumor suppressor, is regulated similarly. Redundant mechanisms to extinguish translational repression by RNA-binding proteins may both control and provide robustness to irreversible developmental transitions, including meiotic maturation and the oocyte-to-embryo transition.
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Affiliation(s)
- Caroline A Spike
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Gabriela Huelgas-Morales
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Tatsuya Tsukamoto
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - David Greenstein
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
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16
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Somatic and Germline MicroRNAs Form Distinct Silencing Complexes to Regulate Their Target mRNAs Differently. Dev Cell 2018; 47:239-247.e4. [PMID: 30245155 DOI: 10.1016/j.devcel.2018.08.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/31/2018] [Accepted: 08/23/2018] [Indexed: 11/23/2022]
Abstract
Animal germ cells possess a specific post-transcriptional regulatory context allowing the storage of maternal transcripts in the oocyte until their translation at a specific point in early development. As key regulators of gene expression, miRNAs repress translation mainly through mRNA destabilization. Thus, germline miRNAs likely use distinct ways to regulate their targets. Here, we use C. elegans to compare miRNA function within germline and somatic tissues. We show that the same miRNA displays tissue-specific gene regulatory mechanisms. While translational repression occurs in both tissues, targeted mRNAs are instead stabilized in the germline. Comparative analyses of miRNA silencing complexes (miRISC) demonstrate that their composition differs from germline to soma. We show that germline miRNA targets preferentially localize to perinuclear regions adjacent to P granules, and their repression is dependent on the core P granule component GLH-1. Together, our findings reveal the existence of different miRISC in animals that affect targeted mRNAs distinctively.
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17
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Gutnik S, Thomas Y, Guo Y, Stoecklin J, Neagu A, Pintard L, Merlet J, Ciosk R. PRP-19, a conserved pre-mRNA processing factor and E3 ubiquitin ligase, inhibits the nuclear accumulation of GLP-1/Notch intracellular domain. Biol Open 2018; 7:bio034066. [PMID: 30012553 PMCID: PMC6078339 DOI: 10.1242/bio.034066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/15/2018] [Indexed: 01/13/2023] Open
Abstract
The Notch signalling pathway is a conserved and widespread signalling paradigm, and its misregulation has been implicated in numerous disorders, including cancer. The output of Notch signalling depends on the nuclear accumulation of the Notch receptor intracellular domain (ICD). Using the Caenorhabditis elegans germline, where GLP-1/Notch-mediated signalling is essential for maintaining stem cells, we monitored GLP-1 in vivo We found that the nuclear enrichment of GLP-1 ICD is dynamic: while the ICD is enriched in germ cell nuclei during larval development, it is depleted from the nuclei in adult germlines. We found that this pattern depends on the ubiquitin proteolytic system and the splicing machinery and, identified the splicing factor PRP-19 as a candidate E3 ubiquitin ligase required for the nuclear depletion of GLP-1 ICD.
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Affiliation(s)
- Silvia Gutnik
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Yann Thomas
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Yanwu Guo
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Janosch Stoecklin
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Anca Neagu
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Lionel Pintard
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Jorge Merlet
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, UMR 7622, F-75005 Paris, France
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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18
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West SM, Mecenas D, Gutwein M, Aristizábal-Corrales D, Piano F, Gunsalus KC. Developmental dynamics of gene expression and alternative polyadenylation in the Caenorhabditis elegans germline. Genome Biol 2018; 19:8. [PMID: 29368663 PMCID: PMC5784609 DOI: 10.1186/s13059-017-1369-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 12/03/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The 3' untranslated regions (UTRs) of mRNAs play a major role in post-transcriptional regulation of gene expression. Selection of transcript cleavage and polyadenylation sites is a dynamic process that produces multiple transcript isoforms for the same gene within and across different cell types. Using LITE-Seq, a new quantitative method to capture transcript 3' ends expressed in vivo, we have characterized sex- and cell type-specific transcriptome-wide changes in gene expression and 3'UTR diversity in Caenorhabditis elegans germline cells undergoing proliferation and differentiation. RESULTS We show that nearly half of germline transcripts are alternatively polyadenylated, that differential regulation of endogenous 3'UTR variants is common, and that alternative isoforms direct distinct spatiotemporal protein expression patterns in vivo. Dynamic expression profiling also reveals temporal regulation of X-linked gene expression, selective stabilization of transcripts, and strong evidence for a novel developmental program that promotes nucleolar dissolution in oocytes. We show that the RNA-binding protein NCL-1/Brat is a posttranscriptional regulator of numerous ribosome-related transcripts that acts through specific U-rich binding motifs to down-regulate mRNAs encoding ribosomal protein subunits, rRNA processing factors, and tRNA synthetases. CONCLUSIONS These results highlight the pervasive nature and functional potential of patterned gene and isoform expression during early animal development.
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Affiliation(s)
- Sean M West
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA
| | - Desirea Mecenas
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA
| | - Michelle Gutwein
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA
| | - David Aristizábal-Corrales
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA
| | - Fabio Piano
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA.
- Center for Genomics & Systems Biology, NYU Abu Dhabi, P.O. Box 129188, Saadiyat Island, Abu Dhabi, United Arab Emirates.
| | - Kristin C Gunsalus
- Center for Genomics & Systems Biology, Department of Biology, New York University, New York, NY, 10012, USA.
- Center for Genomics & Systems Biology, NYU Abu Dhabi, P.O. Box 129188, Saadiyat Island, Abu Dhabi, United Arab Emirates.
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19
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Cell Fate Maintenance and Reprogramming During the Oocyte-to-Embryo Transition. Results Probl Cell Differ 2017; 59:269-286. [PMID: 28247053 DOI: 10.1007/978-3-319-44820-6_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This chapter reviews our current understanding of the mechanisms that regulate reprogramming during the oocyte-to-embryo transition (OET). There are two major events reshaping the transcriptome during OET. One is the clearance of maternal transcripts in the early embryo, extensively reviewed by others. The other event, which is the focus of this chapter, is the embryonic (or zygotic) genome activation (EGA). The mechanisms controlling EGA can be broadly divided into transcriptional and posttranscriptional. The former includes the regulation of the basal transcription machinery, the regulation by specific transcription factors and chromatin modifications. The latter is performed mostly via specific RNA-binding proteins (RBPs). Different animal models have been used to decipher the regulation of EGA. These models are often biased for the specific type of regulation, which is why we discuss the models ranging from invertebrates to mammals. Whether these biases stem from incomplete understanding of EGA in these models, or reflect evolutionarily distinct solutions to EGA regulation, is a key unresolved problem in developmental biology. As the mechanisms controlling developmental reprogramming can, and in some cases have been shown to, function in differentiated cells subjected to induced reprogramming, our understanding of EGA regulation may have implications for the efficiency of induced reprogramming and, thus, for regenerative medicine.
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20
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Subasic D, Stoeger T, Eisenring S, Matia-González AM, Imig J, Zheng X, Xiong L, Gisler P, Eberhard R, Holtackers R, Gerber AP, Pelkmans L, Hengartner MO. Post-transcriptional control of executioner caspases by RNA-binding proteins. Genes Dev 2017; 30:2213-2225. [PMID: 27798844 PMCID: PMC5088569 DOI: 10.1101/gad.285726.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/16/2016] [Indexed: 12/03/2022]
Abstract
In this study, Subasic et al. investigated the post-transcriptional control of caspases. The authors describe four conserved RNA-binding proteins (RBPs) that sequentially repress the CED-3 caspase in distinct regions of the C. elegans germline and identify seven RBPs that regulate human caspase-3 expression and/or activation, suggesting that translational inhibition of executioner caspases by RBPs might be a general strategy used widely across the animal kingdom to control apoptosis. Caspases are key components of apoptotic pathways. Regulation of caspases occurs at several levels, including transcription, proteolytic processing, inhibition of enzymatic function, and protein degradation. In contrast, little is known about the extent of post-transcriptional control of caspases. Here, we describe four conserved RNA-binding proteins (RBPs)—PUF-8, MEX-3, GLD-1, and CGH-1—that sequentially repress the CED-3 caspase in distinct regions of the Caenorhabditis elegans germline. We demonstrate that GLD-1 represses ced-3 mRNA translation via two binding sites in its 3′ untranslated region (UTR), thereby ensuring a dual control of unwanted cell death: at the level of p53/CEP-1 and at the executioner caspase level. Moreover, we identified seven RBPs that regulate human caspase-3 expression and/or activation, including human PUF-8, GLD-1, and CGH-1 homologs PUM1, QKI, and DDX6. Given the presence of unusually long executioner caspase 3′ UTRs in many metazoans, translational control of executioner caspases by RBPs might be a strategy used widely across the animal kingdom to control apoptosis.
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Affiliation(s)
- Deni Subasic
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland.,Molecular Life Sciences PhD Program, Swiss Federal Institute of Technology, University of Zurich, 8057 Zurich, Switzerland
| | - Thomas Stoeger
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland.,Systems Biology PhD Program, Swiss Federal Institute of Technology, University of Zurich, 8057 Zurich, Switzerland
| | - Seline Eisenring
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Ana M Matia-González
- Faculty of Health and Medical Sciences, Department of Microbial and Cellular Sciences, University of Surrey, Stag Hill Campus, GU2 7XH Guildford, United Kingdom
| | - Jochen Imig
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
| | - Xue Zheng
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Lei Xiong
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Pascal Gisler
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Ralf Eberhard
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - René Holtackers
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - André P Gerber
- Faculty of Health and Medical Sciences, Department of Microbial and Cellular Sciences, University of Surrey, Stag Hill Campus, GU2 7XH Guildford, United Kingdom
| | - Lucas Pelkmans
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Michael O Hengartner
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
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21
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Matia-González AM, Iadevaia V, Gerber AP. A versatile tandem RNA isolation procedure to capture in vivo formed mRNA-protein complexes. Methods 2016; 118-119:93-100. [PMID: 27746303 DOI: 10.1016/j.ymeth.2016.10.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 10/05/2016] [Accepted: 10/09/2016] [Indexed: 01/08/2023] Open
Abstract
We describe a tandem RNA isolation procedure (TRIP) that enables purification of in vivo formed messenger ribonucleoprotein (mRNP) complexes. The procedure relies on the purification of polyadenylated mRNAs with oligo(dT) beads from cellular extracts, followed by the capture of specific mRNAs with 3'-biotinylated 2'-O-methylated antisense RNA oligonucleotides, which are recovered with streptavidin beads. TRIP was applied to isolate in vivo crosslinked mRNP complexes from yeast, nematodes and human cells for subsequent analysis of RNAs and bound proteins. The method provides a basis for adaptation to other types of polyadenylated RNAs, enabling the comprehensive identification of bound proteins/RNAs, and the investigation of dynamic rearrangement of mRNPs imposed by cellular or environmental cues.
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Affiliation(s)
- Ana M Matia-González
- Dept. of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Valentina Iadevaia
- Dept. of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - André P Gerber
- Dept. of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
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22
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Chen JX, Cipriani PG, Mecenas D, Polanowska J, Piano F, Gunsalus KC, Selbach M. In Vivo Interaction Proteomics in Caenorhabditis elegans Embryos Provides New Insights into P Granule Dynamics. Mol Cell Proteomics 2016; 15:1642-57. [PMID: 26912668 PMCID: PMC4858945 DOI: 10.1074/mcp.m115.053975] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 02/24/2016] [Indexed: 01/20/2023] Open
Abstract
Studying protein interactions in whole organisms is fundamental to understanding development. Here, we combine in vivo expressed GFP-tagged proteins with quantitative proteomics to identify protein-protein interactions of selected key proteins involved in early C. elegans embryogenesis. Co-affinity purification of interaction partners for eight bait proteins resulted in a pilot in vivo interaction map of proteins with a focus on early development. Our network reflects known biology and is highly enriched in functionally relevant interactions. To demonstrate the utility of the map, we looked for new regulators of P granule dynamics and found that GEI-12, a novel binding partner of the DYRK family kinase MBK-2, is a key regulator of P granule formation and germline maintenance. Our data corroborate a recently proposed model in which the phosphorylation state of GEI-12 controls P granule dynamics. In addition, we find that GEI-12 also induces granule formation in mammalian cells, suggesting a common regulatory mechanism in worms and humans. Our results show that in vivo interaction proteomics provides unique insights into animal development.
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Affiliation(s)
- Jia-Xuan Chen
- From the ‡Max Delbrück Center for Molecular Medicine, D-13092 Berlin, Germany; §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003
| | - Patricia G Cipriani
- §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003; ¶New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Desirea Mecenas
- §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003
| | - Jolanta Polanowska
- §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003; ‖INSERM, U1104, 13288 Marseille, France
| | - Fabio Piano
- §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003; ¶New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Kristin C Gunsalus
- §Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003; ¶New York University Abu Dhabi, Abu Dhabi, United Arab Emirates;
| | - Matthias Selbach
- From the ‡Max Delbrück Center for Molecular Medicine, D-13092 Berlin, Germany; **Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
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23
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Casein kinase II promotes target silencing by miRISC through direct phosphorylation of the DEAD-box RNA helicase CGH-1. Proc Natl Acad Sci U S A 2015; 112:E7213-22. [PMID: 26669440 DOI: 10.1073/pnas.1509499112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
MicroRNAs (miRNAs) play essential, conserved roles in diverse developmental processes through association with the miRNA-induced silencing complex (miRISC). Whereas fundamental insights into the mechanistic framework of miRNA biogenesis and target gene silencing have been established, posttranslational modifications that affect miRISC function are less well understood. Here we report that the conserved serine/threonine kinase, casein kinase II (CK2), promotes miRISC function in Caenorhabditis elegans. CK2 inactivation results in developmental defects that phenocopy loss of miRISC cofactors and enhances the loss of miRNA function in diverse cellular contexts. Whereas CK2 is dispensable for miRNA biogenesis and the stability of miRISC cofactors, it is required for efficient miRISC target mRNA binding and silencing. Importantly, we identify the conserved DEAD-box RNA helicase, CGH-1/DDX6, as a key CK2 substrate within miRISC and demonstrate phosphorylation of a conserved N-terminal serine is required for CGH-1 function in the miRNA pathway.
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24
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Matia-González AM, Laing EE, Gerber AP. Conserved mRNA-binding proteomes in eukaryotic organisms. Nat Struct Mol Biol 2015; 22:1027-33. [PMID: 26595419 PMCID: PMC5759928 DOI: 10.1038/nsmb.3128] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/23/2015] [Indexed: 12/12/2022]
Abstract
RNA-binding proteins (RBPs) are essential for the post-transcriptional regulation of gene expression. Recent high-throughput screens have dramatically increased the number of experimentally identified RBPs; however, comprehensive identification of RBPs within living organisms is elusive. Here we describe the repertoire of 765 and 594 proteins that reproducibly interact with polyadenylated mRNAs in Saccharomyces cerevisiae and Caenorhabditis elegans, respectively. Furthermore, we report the differential association of mRBPs upon apoptosis induction in C. elegans L4 stage larvae. Strikingly, most proteins comprising mRNA-binding proteomes (mRBPomes) are evolutionarily conserved between yeast and C. elegans, including components of early metabolic pathways and the proteasome. Based on our evidence that glycolytic enzymes bind to distinct glycolytic mRNAs, we speculate that enzyme-mRNA interactions relate to an ancient mechanism for post-transcriptional coordination of metabolic pathways, perhaps established during the transition from the early RNA to the protein ‘world’.
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Affiliation(s)
- Ana M Matia-González
- Department of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Emma E Laing
- Department of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - André P Gerber
- Department of Microbial and Cellular Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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25
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Abstract
PABPs [poly(A)-binding proteins] bind to the poly(A) tail of eukaryotic mRNAs and are conserved in species ranging from yeast to human. The prototypical cytoplasmic member, PABP1, is a multifunctional RNA-binding protein with roles in global and mRNA-specific translation and stability, consistent with a function as a central regulator of mRNA fate in the cytoplasm. More limited insight into the molecular functions of other family members is available. However, the consequences of disrupting PABP function in whole organisms is less clear, particularly in vertebrates, and even more so in mammals. In the present review, we discuss current and emerging knowledge with respect to the functions of PABP family members in whole animal studies which, although incomplete, already underlines their biological importance and highlights the need for further intensive research in this area.
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26
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Beadell AV, Haag ES. Evolutionary Dynamics of GLD-1-mRNA complexes in Caenorhabditis nematodes. Genome Biol Evol 2014; 7:314-35. [PMID: 25502909 PMCID: PMC4316625 DOI: 10.1093/gbe/evu272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2014] [Indexed: 12/17/2022] Open
Abstract
Given the large number of RNA-binding proteins and regulatory RNAs within genomes, posttranscriptional regulation may be an underappreciated aspect of cis-regulatory evolution. Here, we focus on nematode germ cells, which are known to rely heavily upon translational control to regulate meiosis and gametogenesis. GLD-1 belongs to the STAR-domain family of RNA-binding proteins, conserved throughout eukaryotes, and functions in Caenorhabditis elegans as a germline-specific translational repressor. A phylogenetic analysis across opisthokonts shows that GLD-1 is most closely related to Drosophila How and deuterostome Quaking, both implicated in alternative splicing. We identify messenger RNAs associated with C. briggsae GLD-1 on a genome-wide scale and provide evidence that many participate in aspects of germline development. By comparing our results with published C. elegans GLD-1 targets, we detect nearly 100 that are conserved between the two species. We also detected several hundred Cbr-GLD-1 targets whose homologs have not been reported to be associated with C. elegans GLD-1 in either of two independent studies. Low expression in C. elegans may explain the failure to detect most of them, but a highly expressed subset are strong candidates for Cbr-GLD-1-specific targets. We examine GLD-1-binding motifs among targets conserved in C. elegans and C. briggsae and find that most, but not all, display evidence of shared ancestral binding sites. Our work illustrates both the conservative and the dynamic character of evolution at the posttranslational level of gene regulation, even between congeners.
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Affiliation(s)
- Alana V Beadell
- Program in Behavior, Evolution, Ecology, and Systematics, University of Maryland, College Park Present address: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
| | - Eric S Haag
- Program in Behavior, Evolution, Ecology, and Systematics, University of Maryland, College Park Department of Biology, University of Maryland, College Park
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27
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Arnold A, Rahman MM, Lee MC, Muehlhaeusser S, Katic I, Gaidatzis D, Hess D, Scheckel C, Wright JE, Stetak A, Boag PR, Ciosk R. Functional characterization of C. elegans Y-box-binding proteins reveals tissue-specific functions and a critical role in the formation of polysomes. Nucleic Acids Res 2014; 42:13353-69. [PMID: 25378320 PMCID: PMC4245946 DOI: 10.1093/nar/gku1077] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The cold shock domain is one of the most highly conserved motifs between bacteria and higher eukaryotes. Y-box-binding proteins represent a subfamily of cold shock domain proteins with pleiotropic functions, ranging from transcription in the nucleus to translation in the cytoplasm. These proteins have been investigated in all major model organisms except Caenorhabditis elegans. In this study, we set out to fill this gap and present a functional characterization of CEYs, the C. elegans Y-box-binding proteins. We find that, similar to other organisms, CEYs are essential for proper gametogenesis. However, we also report a novel function of these proteins in the formation of large polysomes in the soma. In the absence of the somatic CEYs, polysomes are dramatically reduced with a simultaneous increase in monosomes and disomes, which, unexpectedly, has no obvious impact on animal biology. Because transcripts that are enriched in polysomes in wild-type animals tend to be less abundant in the absence of CEYs, our findings suggest that large polysomes might depend on transcript stabilization mediated by CEY proteins.
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Affiliation(s)
- Andreas Arnold
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland University of Basel, Petersplatz 1, CH-4003 Basel, Switzerland
| | - Md Masuder Rahman
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Man Chun Lee
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | | | - Iskra Katic
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland
| | - Dimos Gaidatzis
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland Swiss Institute of Bioinformatics, CH-4058 Basel, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland
| | - Claudia Scheckel
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland University of Basel, Petersplatz 1, CH-4003 Basel, Switzerland
| | - Jane E Wright
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland
| | - Attila Stetak
- Department of Neuroscience, Biozentrum/Pharmazentrum, Basel 4046, Switzerland
| | - Peter R Boag
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Basel 4058, Switzerland
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Tocchini C, Keusch JJ, Miller SB, Finger S, Gut H, Stadler MB, Ciosk R. The TRIM-NHL protein LIN-41 controls the onset of developmental plasticity in Caenorhabditis elegans. PLoS Genet 2014; 10:e1004533. [PMID: 25167051 PMCID: PMC4148191 DOI: 10.1371/journal.pgen.1004533] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 06/11/2014] [Indexed: 12/30/2022] Open
Abstract
The mechanisms controlling cell fate determination and reprogramming are fundamental for development. A profound reprogramming, allowing the production of pluripotent cells in early embryos, takes place during the oocyte-to-embryo transition. To understand how the oocyte reprogramming potential is controlled, we sought Caenorhabditis elegans mutants in which embryonic transcription is initiated precociously in germ cells. This screen identified LIN-41, a TRIM-NHL protein and a component of the somatic heterochronic pathway, as a temporal regulator of pluripotency in the germline. We found that LIN-41 is expressed in the cytoplasm of developing oocytes, which, in lin-41 mutants, acquire pluripotent characteristics of embryonic cells and form teratomas. To understand LIN-41 function in the germline, we conducted structure-function studies. In contrast to other TRIM-NHL proteins, we found that LIN-41 is unlikely to function as an E3 ubiquitin ligase. Similar to other TRIM-NHL proteins, the somatic function of LIN-41 is thought to involve mRNA regulation. Surprisingly, we found that mutations predicted to disrupt the association of LIN-41 with mRNA, which otherwise compromise LIN-41 function in the heterochronic pathway in the soma, have only minor effects in the germline. Similarly, LIN-41-mediated repression of a key somatic mRNA target is dispensable for the germline function. Thus, LIN-41 appears to function in the germline and the soma via different molecular mechanisms. These studies provide the first insight into the mechanism inhibiting the onset of embryonic differentiation in developing oocytes, which is required to ensure a successful transition between generations. Reprogramming into a naïve, pluripotent state during the oocyte-to-embryo transition is directed by the oocyte cytoplasm. To understand how this reprogramming is controlled, we searched for C. elegans mutants in which the activation of embryonic genome, a landmark event demarcating the switch from a germline- to embryo-specific transcription, is initiated precociously in germ cells. This screen identified a novel function for LIN-41, a member of the TRIM-NHL protein family, in preventing a premature onset of embryonic-like differentiation and teratoma formation in developing oocytes, thus ensuring a successful passage between generations. This is the first example of such a regulator in cells that are poised for embryonic development. Interestingly, the majority of molecular “roadblocks” to reprograming that have been identified so far are epigenetic regulators. However, we propose that, at least in germ cells, LIN-41-like regulators may fulfill an analogous role in the cytoplasm, which has possible implications for the generation of human pluripotent stem cells.
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Affiliation(s)
- Cristina Tocchini
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jeremy J. Keusch
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Sarah B. Miller
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Susanne Finger
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Heinz Gut
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Michael B. Stadler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- * E-mail:
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Rousakis A, Vlanti A, Borbolis F, Roumelioti F, Kapetanou M, Syntichaki P. Diverse functions of mRNA metabolism factors in stress defense and aging of Caenorhabditis elegans. PLoS One 2014; 9:e103365. [PMID: 25061667 PMCID: PMC4111499 DOI: 10.1371/journal.pone.0103365] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 07/01/2014] [Indexed: 01/04/2023] Open
Abstract
Processing bodies (PBs) and stress granules (SGs) are related, cytoplasmic RNA-protein complexes that contribute to post-transcriptional gene regulation in all eukaryotic cells. Both structures contain translationally repressed mRNAs and several proteins involved in silencing, stabilization or degradation of mRNAs, especially under environmental stress. Here, we monitored the dynamic formation of PBs and SGs, in somatic cells of adult worms, using fluorescently tagged protein markers of each complex. Both complexes were accumulated in response to various stress conditions, but distinct modes of SG formation were induced, depending on the insult. We also observed an age-dependent accumulation of PBs but not of SGs. We further showed that direct alterations in PB-related genes can influence aging and normal stress responses, beyond their developmental role. In addition, disruption of SG-related genes had diverse effects on development, fertility, lifespan and stress resistance of worms. Our work therefore underlines the important roles of mRNA metabolism factors in several vital cellular processes and provides insight into their diverse functions in a multicellular organism.
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Affiliation(s)
- Aris Rousakis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
- Faculty of Medicine, University of Athens, Athens, Greece
| | - Anna Vlanti
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
| | - Fivos Borbolis
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
- Faculty of Biology, School of Science, University of Athens, Athens, Greece
| | - Fani Roumelioti
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
- Faculty of Biology, School of Science, University of Athens, Athens, Greece
| | - Marianna Kapetanou
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
- Department of Biology, School of Science and Engineering, University of Crete, Heraklio, Crete, Greece
| | - Popi Syntichaki
- Biomedical Research Foundation of the Academy of Athens, Center of Basic Research II, Athens, Greece
- * E-mail:
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30
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Daubner GM, Brümmer A, Tocchini C, Gerhardy S, Ciosk R, Zavolan M, Allain FHT. Structural and functional implications of the QUA2 domain on RNA recognition by GLD-1. Nucleic Acids Res 2014; 42:8092-105. [PMID: 24838563 PMCID: PMC4081071 DOI: 10.1093/nar/gku445] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 05/04/2014] [Accepted: 05/06/2014] [Indexed: 01/13/2023] Open
Abstract
The STAR family comprises ribonucleic acid (RNA)-binding proteins that play key roles in RNA-regulatory processes. RNA recognition is achieved by a KH domain with an additional α-helix (QUA2) that seems to extend the RNA-binding surface to six nucleotides for SF1 (Homo sapiens) and seven nucleotides for GLD-1 (Caenorhabditis elegans). To understand the structural basis of this probable difference in specificity, we determined the solution structure of GLD-1 KH-QUA2 with the complete consensus sequence identified in the tra-2 gene. Compared to SF1, the GLD-1 KH-QUA2 interface adopts a different conformation resulting indeed in an additional sequence-specific binding pocket for a uracil at the 5'end. The functional relevance of this binding pocket is emphasized by our bioinformatics analysis showing that GLD-1 binding sites with this 5'end uracil are more predictive for the functional response of the messenger RNAs to gld-1 knockout. We further reveal the importance of the KH-QUA2 interface in vitro and that its alteration in vivo affects the level of translational repression dependent on the sequence of the GLD-1 binding motif. In conclusion, we demonstrate that the QUA2 domain distinguishes GLD-1 from other members of the STAR family and contributes more generally to the modulation of RNA-binding affinity and specificity of KH domain containing proteins.
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Affiliation(s)
- Gerrit M Daubner
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - Anneke Brümmer
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Cristina Tocchini
- Friedrich Miescher Institute for Biomedical Research, 4002 Basel, Switzerland
| | - Stefan Gerhardy
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, 4002 Basel, Switzerland
| | | | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
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31
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Juang BT, Ludwig AL, Benedetti KL, Gu C, Collins K, Morales C, Asundi A, Wittmann T, L'Etoile N, Hagerman PJ. Expression of an expanded CGG-repeat RNA in a single pair of primary sensory neurons impairs olfactory adaptation in Caenorhabditis elegans. Hum Mol Genet 2014; 23:4945-59. [PMID: 24821701 PMCID: PMC4140470 DOI: 10.1093/hmg/ddu210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a severe neurodegenerative disorder that affects carriers of premutation CGG-repeat expansion alleles of the fragile X mental retardation 1 (FMR1) gene; current evidence supports a causal role of the expanded CGG repeat within the FMR1 mRNA in the pathogenesis of FXTAS. Though the mRNA has been observed to induce cellular toxicity in FXTAS, the mechanisms are unclear. One common neurophysiological characteristic of FXTAS patients is their inability to properly attenuate their response to an auditory stimulus upon receipt of a small pre-stimulus. Therefore, to gain genetic and cell biological insight into FXTAS, we examined the effect of expanded CGG repeats on the plasticity of the olfactory response of the genetically tractable nematode, Caenorhabditis elegans (C. elegans). While C. elegans is innately attracted to odors, this response can be downregulated if the odor is paired with starvation. We found that expressing expanded CGG repeats in olfactory neurons interfered with this plasticity without affecting either the innate odor-seeking response or the olfactory neuronal morphology. Interrogation of three RNA regulatory pathways indicated that the expanded CGG repeats act via the C. elegans microRNA (miRNA)-specific Argonaute ALG-2 to diminish olfactory plasticity. This observation suggests that the miRNA-Argonaute pathway may play a pathogenic role in subverting neuronal function in FXTAS.
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Affiliation(s)
- Bi-Tzen Juang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Anna L Ludwig
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Kelli L Benedetti
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Chen Gu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kimberly Collins
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Christopher Morales
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aarati Asundi
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Torsten Wittmann
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Noelle L'Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Paul J Hagerman
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, CA 95616, USA, MIND Institute, University of California, Davis, Health System, Sacramento, CA 95817, USA
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Wang X, Gupta P, Fairbanks J, Hansen D. Protein kinase CK2 both promotes robust proliferation and inhibits the proliferative fate in the C. elegans germ line. Dev Biol 2014; 392:26-41. [PMID: 24824786 DOI: 10.1016/j.ydbio.2014.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/02/2014] [Accepted: 05/02/2014] [Indexed: 11/18/2022]
Abstract
Stem cells are capable of both self-renewal (proliferation) and differentiation. Determining the regulatory mechanisms controlling the balance between stem cell proliferation and differentiation is not only an important biological question, but also holds the key for using stem cells as therapeutic agents. The Caenorhabditis elegans germ line has emerged as a valuable model to study the molecular mechanisms controlling stem cell behavior. In this study, we describe a large-scale RNAi screen that identified kin-10, which encodes the β subunit of protein kinase CK2, as a novel factor regulating stem cell proliferation in the C. elegans germ line. While a loss of kin-10 in an otherwise wild-type background results in a decrease in the number of proliferative cells, loss of kin-10 in sensitized genetic backgrounds results in a germline tumor. Therefore, kin-10 is not only necessary for robust proliferation, it also inhibits the proliferative fate. We found that kin-10's regulatory role in inhibiting the proliferative fate is carried out through the CK2 holoenzyme, rather than through a holoenzyme-independent function, and that it functions downstream of GLP-1/Notch signaling. We propose that a loss of kin-10 leads to a defect in CK2 phosphorylation of its downstream targets, resulting in abnormal activity of target protein(s) that are involved in the proliferative fate vs. differentiation decision. This eventually causes a shift towards the proliferative fate in the stem cell fate decision.
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Affiliation(s)
- Xin Wang
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Pratyush Gupta
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Jared Fairbanks
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Dave Hansen
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4.
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33
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Doh JH, Jung Y, Reinke V, Lee MH. C. elegans RNA-binding protein GLD-1 recognizes its multiple targets using sequence, context, and structural information to repress translation. WORM 2014; 2:e26548. [PMID: 24744981 DOI: 10.4161/worm.26548] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/12/2013] [Accepted: 09/19/2013] [Indexed: 11/19/2022]
Abstract
Caenorhabditis elegans GLD-1, a maxi-KH motif containing RNA-binding protein, has various functions mainly during female germ cell development, suggesting that it likely controls the expression of a selective group of maternal mRNAs. To gain an insight into how GLD-1 specifically recognizes these mRNA targets, we identified 38 biochemically proven GLD-1 binding regions from multiple mRNA targets that are among over 100 putative targets co-immunoprecipitated with GLD-1. The sequence information of these regions revealed three over-represented and phylogenetically conserved sequence motifs. We found that two of the motifs, one of which is novel, are important for GLD-1 binding in several GLD-1 binding regions but not in other regions. Further analyses indicate that the importance of one of the sequence motifs is dependent on two aspects: (1) surrounding sequence information, likely acting as an accessory feature for GLD-1 to efficiently select the sequence motif and (2) RNA secondary structural environment where the sequence motif resides, which likely provides "binding-site accessibility" for GLD-1 to effectively recognize its targets. Our data suggest some mRNAs recruit GLD-1 by a distinct mechanism, which involves more than one sequence motif that needs to be embedded in the correct context and structural environment.
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Affiliation(s)
- Jung H Doh
- Department of Biological Sciences; University at Albany; SUNY; Albany, NY USA
| | - Yuchae Jung
- Department of Biological Sciences; University at Albany; SUNY; Albany, NY USA
| | - Valerie Reinke
- Department of Genetics; Yale University School of Medicine; New Haven, CT USA
| | - Min-Ho Lee
- Department of Biological Sciences; University at Albany; SUNY; Albany, NY USA
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Brümmer A, Hausser J. MicroRNA binding sites in the coding region of mRNAs: extending the repertoire of post-transcriptional gene regulation. Bioessays 2014; 36:617-26. [PMID: 24737341 DOI: 10.1002/bies.201300104] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is well established that microRNAs (miRNAs) induce mRNA degradation by binding to 3' untranslated regions (UTRs). The functionality of sites in the coding domain sequence (CDS), on the other hand, remains under discussion. Such sites have limited impact on target mRNA abundance and recent work suggests that miRNAs bind in the CDS to inhibit translation. What then could be the regulatory benefits of translation inhibition through CDS targeting compared to mRNA degradation following 3' UTR binding? We propose that these domain-dependent effects serve to diversify the functional repertoire of post-transcriptional gene expression control. Possible regulatory benefits may include tuning the time-scale and magnitude of post-transcriptional regulation, regulating protein abundance depending on or independently of the cellular state, and regulation of the protein abundance of alternative splice variants. Finally, we review emerging evidence that these ideas may generalize to RNA-binding proteins beyond miRNAs and Argonaute proteins.
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35
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Giuliani G, Giuliani F, Volk T, Rabouille C. The Drosophila RNA-binding protein HOW controls the stability of dgrasp mRNA in the follicular epithelium. Nucleic Acids Res 2014; 42:1970-86. [PMID: 24217913 PMCID: PMC3919595 DOI: 10.1093/nar/gkt1118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 10/18/2013] [Accepted: 10/22/2013] [Indexed: 11/14/2022] Open
Abstract
Post-transcriptional regulation of RNA stability and localization underlies a wide array of developmental processes, such as axon guidance and epithelial morphogenesis. In Drosophila, ectopic expression of the classically Golgi peripheral protein dGRASP at the plasma membrane is achieved through its mRNA targeting at key developmental time-points, in a process critical to follicular epithelium integrity. However, the trans-acting factors that tightly regulate the spatio-temporal dynamics of dgrasp are unknown. Using an in silico approach, we identified two putative HOW Response Elements (HRE1 and HRE2) within the dgrasp open reading frame for binding to Held Out Wings (HOW), a member of the Signal Transduction and Activation of RNA family of RNA-binding proteins. Using RNA immunoprecipitations, we confirmed this by showing that the short cytoplasmic isoform of HOW binds directly to dgrasp HRE1. Furthermore, HOW loss of function in vivo leads to a significant decrease in dgrasp mRNA levels. We demonstrate that HRE1 protects dgrasp mRNA from cytoplasmic degradation, but does not mediate its targeting. We propose that this binding event promotes the formation of ribonucleoprotein particles that ensure dgrasp stability during transport to the basal plasma membrane, thus enabling the local translation of dgrasp for its roles at non-Golgi locations.
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Affiliation(s)
- Giuliano Giuliani
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Fabrizio Giuliani
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Talila Volk
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
| | - Catherine Rabouille
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands, Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel and The Department of Cell Biology, UMC Utrecht, The Netherlands
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36
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Ko S, Kawasaki I, Shim YH. PAB-1, a Caenorhabditis elegans poly(A)-binding protein, regulates mRNA metabolism in germline by interacting with CGH-1 and CAR-1. PLoS One 2013; 8:e84798. [PMID: 24367695 PMCID: PMC3868610 DOI: 10.1371/journal.pone.0084798] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/19/2013] [Indexed: 11/25/2022] Open
Abstract
Poly(A)-binding proteins are highly conserved among eukaryotes and regulate stability of mRNA and translation. Among C. elegans homologues, pab-1 mutants showed defects in germline mitotic proliferation. Unlike pab-1 mutants, pab-1 RNAi at every larval stage caused arrest of germline development at the following stage, indicating that pab-1 is required for the entire postembryonic germline development. This idea is supported by the observations that the mRNA level of pab-1 increased throughout postembryonic development and its protein expression was germline-enriched. PAB-1 localized to P granules and the cytoplasm in the germline. PAB-1 colocalized with CGH-1 and CAR-1 and affected their localization, suggesting that PAB-1 is a component of processing (P)-bodies that interacts with them. The mRNA and protein levels of representative germline genes, rec-8, GLP-1, rme-2, and msp-152, were decreased after pab-1 RNAi. Although the mRNA level of msp-152 was increased in cgh-1 mutant, it was also significantly reduced by pab-1 RNAi. Our results suggest that PAB-1 positively regulates the mRNA levels of germline genes, which is likely facilitated by the interaction of PAB-1 with other P-body components, CGH-1 and CAR-1.
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Affiliation(s)
- Sunhee Ko
- Department of Bioscience and Biotechnology, Institute of KU Biotechnology, Konkuk University, Seoul, South Korea
| | - Ichiro Kawasaki
- Department of Bioscience and Biotechnology, Institute of KU Biotechnology, Konkuk University, Seoul, South Korea
| | - Yhong-Hee Shim
- Department of Bioscience and Biotechnology, Institute of KU Biotechnology, Konkuk University, Seoul, South Korea
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Akay A, Craig A, Lehrbach N, Larance M, Pourkarimi E, Wright JE, Lamond A, Miska E, Gartner A. RNA-binding protein GLD-1/quaking genetically interacts with the mir-35 and the let-7 miRNA pathways in Caenorhabditis elegans. Open Biol 2013; 3:130151. [PMID: 24258276 PMCID: PMC3843822 DOI: 10.1098/rsob.130151] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/25/2013] [Indexed: 12/30/2022] Open
Abstract
Messenger RNA translation is regulated by RNA-binding proteins and small non-coding RNAs called microRNAs. Even though we know the majority of RNA-binding proteins and microRNAs that regulate messenger RNA expression, evidence of interactions between the two remain elusive. The role of the RNA-binding protein GLD-1 as a translational repressor is well studied during Caenorhabditis elegans germline development and maintenance. Possible functions of GLD-1 during somatic development and the mechanism of how GLD-1 acts as a translational repressor are not known. Its human homologue, quaking (QKI), is essential for embryonic development. Here, we report that the RNA-binding protein GLD-1 in C. elegans affects multiple microRNA pathways and interacts with proteins required for microRNA function. Using genome-wide RNAi screening, we found that nhl-2 and vig-1, two known modulators of miRNA function, genetically interact with GLD-1. gld-1 mutations enhance multiple phenotypes conferred by mir-35 and let-7 family mutants during somatic development. We used stable isotope labelling with amino acids in cell culture to globally analyse the changes in the proteome conferred by let-7 and gld-1 during animal development. We identified the histone mRNA-binding protein CDL-1 to be, in part, responsible for the phenotypes observed in let-7 and gld-1 mutants. The link between GLD-1 and miRNA-mediated gene regulation is further supported by its biochemical interaction with ALG-1, CGH-1 and PAB-1, proteins implicated in miRNA regulation. Overall, we have uncovered genetic and biochemical interactions between GLD-1 and miRNA pathways.
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Affiliation(s)
- Alper Akay
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
| | - Ashley Craig
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
| | - Nicolas Lehrbach
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
| | - Mark Larance
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
| | - Ehsan Pourkarimi
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
| | - Jane E. Wright
- Friedrich Miescher Institute for Biomedical Research, Basel 4002, Switzerland
| | - Angus Lamond
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
| | - Eric Miska
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
| | - Anton Gartner
- Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK
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Brümmer A, Kishore S, Subasic D, Hengartner M, Zavolan M. Modeling the binding specificity of the RNA-binding protein GLD-1 suggests a function of coding region-located sites in translational repression. RNA (NEW YORK, N.Y.) 2013; 19:1317-1326. [PMID: 23974436 PMCID: PMC3854522 DOI: 10.1261/rna.037531.112] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 06/25/2013] [Indexed: 06/02/2023]
Abstract
To understand the function of the hundreds of RNA-binding proteins (RBPs) that are encoded in animal genomes it is important to identify their target RNAs. Although it is generally accepted that the binding specificity of an RBP is well described in terms of the nucleotide sequence of its binding sites, other factors such as the structural accessibility of binding sites or their clustering, to enable binding of RBP multimers, are also believed to play a role. Here we focus on GLD-1, a translational regulator of Caenorhabditis elegans, whose binding specificity and targets have been studied with a variety of methods such as CLIP (cross-linking and immunoprecipitation), RIP-Chip (microarray measurement of RNAs associated with an immunoprecipitated protein), profiling of polysome-associated mRNAs and biophysical determination of binding affinities of GLD-1 for short nucleotide sequences. We show that a simple biophysical model explains the binding of GLD-1 to mRNA targets to a large extent, and that taking into account the accessibility of putative target sites significantly improves the prediction of GLD-1 binding, particularly due to a more accurate prediction of binding in transcript coding regions. Relating GLD-1 binding to translational repression and stabilization of its target transcripts we find that binding sites along the entire transcripts contribute to functional responses, and that CDS-located sites contribute most to translational repression. Finally, biophysical measurements of GLD-1 affinity for a small number of oligonucleotides appear to allow an accurate reconstruction of the sequence specificity of the protein. This approach can be applied to uncover the specificity and function of other RBPs.
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Affiliation(s)
- Anneke Brümmer
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Deni Subasic
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
| | - Michael Hengartner
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland
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Voronina E. The diverse functions of germline P-granules in Caenorhabditis elegans. Mol Reprod Dev 2012; 80:624-31. [PMID: 23150384 DOI: 10.1002/mrd.22136] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 11/05/2012] [Indexed: 12/14/2022]
Abstract
P-granules are conserved cytoplasmic organelles, similar to nuage, that are present in Caenorhabditis elegans germ cells. Based on the prevailing sterility phenotype of the component mutants, P-granules have been seen as regulators of germ cell development and function. Yet, specific germline defects resulting from P-granule failure vary, depending on which component(s) are inactivated, at which stage of development, as well as on the presence of stress factors during animal culture. This review discusses the unifying themes in many P-granule functions, with the main focus on their role as organizing centers nucleating RNA regulation in the germ cell cytoplasm.
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Affiliation(s)
- Ekaterina Voronina
- Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA.
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Wright JE, Ciosk R. RNA-based regulation of pluripotency. Trends Genet 2012; 29:99-107. [PMID: 23146412 DOI: 10.1016/j.tig.2012.10.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/01/2012] [Accepted: 10/08/2012] [Indexed: 01/01/2023]
Abstract
Pluripotent cells have the unique ability to differentiate into diverse cell types. Over the past decade our understanding of the mechanisms underlying pluripotency, and particularly the role of transcriptional regulation, has increased dramatically. However, there is growing evidence for 'RNA-based' regulation of pluripotency. We use this term to describe control of gene expression by RNA-binding proteins (RBPs) and regulatory non-coding RNAs (ncRNAs). These molecules bind to specific elements within mRNAs and, by recruiting various effectors, affect many aspects of mRNA regulation. Here, we discuss the role of RBPs and ncRNAs in both the induction and maintenance of pluripotency. We highlight and contrast examples from pluripotent cell lines and in vivo systems while discussing the connection to transcriptional regulators.
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Affiliation(s)
- Jane E Wright
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
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Farley BM, Ryder SP. POS-1 and GLD-1 repress glp-1 translation through a conserved binding-site cluster. Mol Biol Cell 2012; 23:4473-83. [PMID: 23034181 PMCID: PMC3510010 DOI: 10.1091/mbc.e12-03-0216] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
RNA-binding proteins (RBPs) coordinate cell fate specification and differentiation in a variety of systems. RNA regulation is critical during oocyte development and early embryogenesis, in which RBPs control expression from maternal mRNAs encoding key cell fate determinants. The Caenorhabditis elegans Notch homologue glp-1 coordinates germline progenitor cell proliferation and anterior fate specification in embryos. A network of sequence-specific RBPs is required to pattern GLP-1 translation. Here, we map the cis-regulatory elements that guide glp-1 regulation by the CCCH-type tandem zinc finger protein POS-1 and the STAR-domain protein GLD-1. Our results demonstrate that both proteins recognize the glp-1 3' untranslated region (UTR) through adjacent, overlapping binding sites and that POS-1 binding excludes GLD-1 binding. Both factors are required to repress glp-1 translation in the embryo, suggesting that they function in parallel regulatory pathways. It is intriguing that two equivalent POS-1-binding sites are present in the glp-1 3' UTR, but only one, which overlaps with a translational derepression element, is functional in vivo. We propose that POS-1 regulates glp-1 mRNA translation by blocking access of other RBPs to a key regulatory sequence.
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Affiliation(s)
- Brian M Farley
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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