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Lederbauer J, Das S, Piton A, Lessel D, Kreienkamp HJ. The role of DEAD- and DExH-box RNA helicases in neurodevelopmental disorders. Front Mol Neurosci 2024; 17:1414949. [PMID: 39149612 PMCID: PMC11324592 DOI: 10.3389/fnmol.2024.1414949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/22/2024] [Indexed: 08/17/2024] Open
Abstract
Neurodevelopmental disorders (NDDs) represent a large group of disorders with an onset in the neonatal or early childhood period; NDDs include intellectual disability (ID), autism spectrum disorders (ASD), attention deficit hyperactivity disorders (ADHD), seizures, various motor disabilities and abnormal muscle tone. Among the many underlying Mendelian genetic causes for these conditions, genes coding for proteins involved in all aspects of the gene expression pathway, ranging from transcription, splicing, translation to the eventual RNA decay, feature rather prominently. Here we focus on two large families of RNA helicases (DEAD- and DExH-box helicases). Genetic variants in the coding genes for several helicases have recently been shown to be associated with NDD. We address genetic constraints for helicases, types of pathological variants which have been discovered and discuss the biological pathways in which the affected helicase proteins are involved.
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Affiliation(s)
- Johannes Lederbauer
- Institute of Human Genetics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sarada Das
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Amelie Piton
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology, Strasbourg University, CNRS UMR7104, INSERM U1258, Illkirch, France
| | - Davor Lessel
- Institute of Human Genetics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans-Jürgen Kreienkamp
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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2
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Wang JY, Liu YJ, Zhang XL, Liu YH, Jiang LL, Hu HY. PolyQ-expanded ataxin-2 aggregation impairs cellular processing-body homeostasis via sequestering the RNA helicase DDX6. J Biol Chem 2024; 300:107413. [PMID: 38810698 PMCID: PMC11254730 DOI: 10.1016/j.jbc.2024.107413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 05/31/2024] Open
Abstract
Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.
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Affiliation(s)
- Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Yin-Hu Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China.
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3
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Buchan JR. Stress granule and P-body clearance: Seeking coherence in acts of disappearance. Semin Cell Dev Biol 2024; 159-160:10-26. [PMID: 38278052 PMCID: PMC10939798 DOI: 10.1016/j.semcdb.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/28/2024]
Abstract
Stress granules and P-bodies are conserved cytoplasmic biomolecular condensates whose assembly and composition are well documented, but whose clearance mechanisms remain controversial or poorly described. Such understanding could provide new insight into how cells regulate biomolecular condensate formation and function, and identify therapeutic strategies in disease states where aberrant persistence of stress granules in particular is implicated. Here, I review and compare the contributions of chaperones, the cytoskeleton, post-translational modifications, RNA helicases, granulophagy and the proteasome to stress granule and P-body clearance. Additionally, I highlight the potentially vital role of RNA regulation, cellular energy, and changes in the interaction networks of stress granules and P-bodies as means of eliciting clearance. Finally, I discuss evidence for interplay of distinct clearance mechanisms, suggest future experimental directions, and suggest a simple working model of stress granule clearance.
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Affiliation(s)
- J Ross Buchan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson 85716, United States.
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4
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Gao M. Me31B: a key repressor in germline regulation and beyond. Biosci Rep 2024; 44:BSR20231769. [PMID: 38606619 PMCID: PMC11065648 DOI: 10.1042/bsr20231769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/13/2024] Open
Abstract
Maternally Expressed at 31B (Me31B), an evolutionarily conserved ATP-dependent RNA helicase, plays an important role in the development of the germline across diverse animal species. Its cellular functionality has been posited as a translational repressor, participating in various RNA metabolism pathways to intricately regulate the spatiotemporal expression of RNAs. Despite its evident significance, the precise role and mechanistic underpinnings of Me31B remain insufficiently understood. This article endeavors to comprehensively review historic and recent research on Me31B, distill the major findings, discern generalizable patterns in Me31B's functions across different research contexts, and provide insights into its fundamental role and mechanism of action. The primary focus of this article centers on elucidating the role of Drosophila Me31B within the germline, while concurrently delving into pertinent research on its orthologs within other species and cellular systems.
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Affiliation(s)
- Ming Gao
- Biology Department, Indiana University Northwest, Gary, IN, U.S.A
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5
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Min H, Liang X, Wang C, Qin J, Boonhok R, Muneer A, Brashear AM, Li X, Minns AM, Adapa SR, Jiang RHY, Ning G, Cao Y, Lindner SE, Miao J, Cui L. The DEAD-box RNA helicase PfDOZI imposes opposing actions on RNA metabolism in Plasmodium falciparum. Nat Commun 2024; 15:3747. [PMID: 38702310 PMCID: PMC11068891 DOI: 10.1038/s41467-024-48140-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/19/2024] [Indexed: 05/06/2024] Open
Abstract
In malaria parasites, the regulation of mRNA translation, storage and degradation during development and life-stage transitions remains largely unknown. Here, we functionally characterized the DEAD-box RNA helicase PfDOZI in P. falciparum. Disruption of pfdozi enhanced asexual proliferation but reduced sexual commitment and impaired gametocyte development. By quantitative transcriptomics, we show that PfDOZI is involved in the regulation of invasion-related genes and sexual stage-specific genes during different developmental stages. PfDOZI predominantly participates in processing body-like mRNPs in schizonts but germ cell granule-like mRNPs in gametocytes to impose opposing actions of degradation and protection on different mRNA targets. We further show the formation of stress granule-like mRNPs during nutritional deprivation, highlighting an essential role of PfDOZI-associated mRNPs in stress response. We demonstrate that PfDOZI participates in distinct mRNPs to maintain mRNA homeostasis in response to life-stage transition and environmental changes by differentially executing post-transcriptional regulation on the target mRNAs.
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Affiliation(s)
- Hui Min
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Xiaoying Liang
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Junling Qin
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
| | - Rachasak Boonhok
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat, 80160, Thailand
| | - Azhar Muneer
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
| | - Awtum M Brashear
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
| | - Xiaolian Li
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA
| | - Allen M Minns
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, 16802, USA
| | - Swamy Rakesh Adapa
- Center for Global Health and Infectious Diseases, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Rays H Y Jiang
- Center for Global Health and Infectious Diseases, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Gang Ning
- Electron Microscopy Facility, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, Pennsylvania State University, University Park, PA, 16802, USA
| | - Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA.
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL, 33612, USA.
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6
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Deng X, Liu Z, Wang B, Ma J, Meng X. The DDX6/KIFC1 signaling axis, as regulated by YY1, contributes to the malignant behavior of pancreatic cancer. FASEB J 2024; 38:e23581. [PMID: 38551642 DOI: 10.1096/fj.202400166r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/07/2024] [Accepted: 03/15/2024] [Indexed: 04/02/2024]
Abstract
Human DEAD/H box RNA helicase DDX6 acts as an oncogene in several different types of cancer, where it participates in RNA processing. Nevertheless, the role of DDX6 in pancreatic cancer (PC), together with the underlying mechanism, has yet to be fully elucidated. In the present study, compared with adjacent tissues, the level of DDX6 was abnormally increased in human PC tissues, and this increased level of expression was associated with poor prognosis. Furthermore, the role of DDX6 in PC was investigated by overexpressing or silencing the DDX6 in the PC cell lines, SW1990 and PaTu-8988t. A xenograft model was established by injecting nude mice with either DDX6-overexpressing or DDX6-silenced SW1990 cells. DDX6 overexpression promoted the proliferation and cell cycle transition, inhibited the cell apoptosis of PC cells, and accelerated tumor formation, whereas DDX6 knockdown elicited the opposite effects. DDX6 exerted positive effects on PC. RNA immunoprecipitation assay showed that DDX6 bound to kinesin family member C1 (KIFC1) mRNA, which was further confirmed by RNA pull-down assay. These results suggested that DDX6 positively regulated the expression of KIFC1. KIFC1 overexpression enhanced the proliferative capability of PC cells with DDX6 knockdown and inhibited their apoptosis. By contrast, DDX6 overexpression reversed the inhibitory effect of KIFC1 silencing on tumor proliferation. Subsequently, the transcription factor Yin Yang 1 (YY1) was shown to negatively regulate DDX6 at both the mRNA and protein levels. Dual-luciferase reporter assay verified that YY1 targeted the promoter of DDX6 and inhibited its transcription. High expression levels of YY1 decreased the proliferation of PC cells and promoted cell apoptosis, although these effects were reversed by DDX6 overexpression. Taken together, YY1 may target the DDX6/KIFC1 axis, thereby negatively regulating its expression, leading to an inhibitory effect on pancreatic tumor.
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Affiliation(s)
- Xin Deng
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Zhen Liu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Baosheng Wang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Jia Ma
- Department of Gastroenterology, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Xiangpeng Meng
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
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7
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Majerciak V, Zhou T, Kruhlak M, Zheng ZM. RNA helicase DDX6 and scaffold protein GW182 in P-bodies promote biogenesis of stress granules. Nucleic Acids Res 2023; 51:9337-9355. [PMID: 37427791 PMCID: PMC10516652 DOI: 10.1093/nar/gkad585] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 06/05/2023] [Accepted: 07/07/2023] [Indexed: 07/11/2023] Open
Abstract
Two prominent cytoplasmic RNA granules, ubiquitous RNA-processing bodies (PB) and inducible stress granules (SG), regulate mRNA translation and are intimately related. In this study, we found that arsenite (ARS)-induced SG formed in a stepwise process is topologically and mechanically linked to PB. Two essential PB components, GW182 and DDX6, are repurposed under stress to play direct but distinguishable roles in SG biogenesis. By providing scaffolding activities, GW182 promotes the aggregation of SG components to form SG bodies. DEAD-box helicase DDX6 is also essential for the proper assembly and separation of PB from SG. DDX6 deficiency results in the formation of irregularly shaped 'hybrid' PB/SG granules with accumulated components of both PB and SG. Wild-type DDX6, but not its helicase mutant E247A, can rescue the separation of PB from SG in DDX6KO cells, indicating a requirement of DDX6 helicase activity for this process. DDX6 activity in biogenesis of both PB and SG in the cells under stress is further modulated by its interaction with two protein partners, CNOT1 and 4E-T, of which knockdown affects the formation of both PB and also SG. Together, these data highlight a new functional paradigm between PB and SG biogenesis during the stress.
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Affiliation(s)
- Vladimir Majerciak
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Tongqing Zhou
- Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael J Kruhlak
- CCR Confocal Microscopy Core Facility, Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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8
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Kara E, McCambridge A, Proffer M, Dilts C, Pumnea B, Eshak J, Smith KA, Fielder I, Doyle DA, Ortega BM, Mukatash Y, Malik N, Mohammed AR, Govani D, Niepielko MG, Gao M. Mutational analysis of the functional motifs of the DEAD-box RNA helicase Me31B/DDX6 in Drosophila germline development. FEBS Lett 2023; 597:1848-1867. [PMID: 37235728 PMCID: PMC10389067 DOI: 10.1002/1873-3468.14668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/24/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023]
Abstract
Me31B/DDX6 is a DEAD-box family RNA helicase playing roles in post-transcriptional RNA regulation in different cell types and species. Despite the known motifs/domains of Me31B, the in vivo functions of the motifs remain unclear. Here, we used the Drosophila germline as a model and used CRISPR to mutate the key Me31B motifs/domains: helicase domain, N-terminal domain, C-terminal domain and FDF-binding motif. Then, we performed screening characterization on the mutants and report the effects of the mutations on the Drosophila germline, on processes such as fertility, oogenesis, embryo patterning, germline mRNA regulation and Me31B protein expression. The study indicates that the Me31B motifs contribute different functions to the protein and are needed for proper germline development, providing insights into the in vivo working mechanism of the helicase.
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Affiliation(s)
- Evan Kara
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | - Megan Proffer
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Carol Dilts
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Brooke Pumnea
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - John Eshak
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Korey A. Smith
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Isaac Fielder
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Dominique A. Doyle
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
| | - Bianca M. Ortega
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
| | - Yousif Mukatash
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Noor Malik
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | - Deep Govani
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Matthew G. Niepielko
- School of Integrative Science and Technology, Kean University, Union, NJ, USA
- Biology Department, Kean University, Union, NJ, USA
| | - Ming Gao
- Biology Department, Indiana University Northwest, Gary, IN, USA
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9
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Liu Y, Hao Y. Exploring the Possibility of RNA in Diverse Biological Processes. Int J Mol Sci 2023; 24:10674. [PMID: 37445851 DOI: 10.3390/ijms241310674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
The total amount of RNA in a cell is 5 to 10 times greater than that of DNA [...].
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Affiliation(s)
- Yanchen Liu
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing 100101, China
| | - Yajing Hao
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing 100101, China
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
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10
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Li H, Zhao H, Yang C, Su R, Long M, Liu J, Shi L, Xue Y, Su Y. LSM14B is an Oocyte-Specific RNA-Binding Protein Indispensable for Maternal mRNA Metabolism and Oocyte Development in Mice. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300043. [PMID: 37083226 PMCID: PMC10288277 DOI: 10.1002/advs.202300043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/28/2023] [Indexed: 05/03/2023]
Abstract
Mammalian oogenesis features reliance on the mRNAs produced and stored during early growth phase. These are essential for producing an oocyte competent to undergo meiotic maturation and embryogenesis later when oocytes are transcriptionally silent. The fate of maternal mRNAs hence ensures the success of oogenesis and the quality of the resulting eggs. Nevertheless, how the fate of maternal mRNAs is determined remains largely elusive. RNA-binding proteins (RBPs) are crucial regulators of oogenesis, yet the identity of the full complement of RBPs expressed in oocytes is unknown. Here, a global view of oocyte-expressed RBPs is presented: mRNA-interactome capture identifies 1396 RBPs in mouse oocytes. An analysis of one of these RBPs, LSM family member 14 (LSM14B), demonstrates that this RBP is specific to oocytes and associated with many networks essential for oogenesis. Deletion of Lsm14b results in female-specific infertility and a phenotype characterized by oocytes incompetent to complete meiosis and early embryogenesis. LSM14B serves as an interaction hub for proteins and mRNAs throughout oocyte development and regulates translation of a subset of its bound mRNAs. Therefore, RNP complexes tethered by LSM14B are found exclusively in oocytes and are essential for the control of maternal mRNA fate and oocyte development.
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Affiliation(s)
- Hui Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
- State Key Laboratory of Reproductive MedicineNanjing Medical UniversityNanjing211126P. R. China
| | - Hailian Zhao
- Institute of BiophysicsChinese Academy of SciencesBeijing100101P. R. China
| | - Chunhui Yang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
| | - Ruibao Su
- Institute of BiophysicsChinese Academy of SciencesBeijing100101P. R. China
| | - Min Long
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
- State Key Laboratory of Reproductive MedicineNanjing Medical UniversityNanjing211126P. R. China
| | - Jinliang Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
| | - Lanying Shi
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
- State Key Laboratory of Reproductive MedicineNanjing Medical UniversityNanjing211126P. R. China
| | - Yuanchao Xue
- Institute of BiophysicsChinese Academy of SciencesBeijing100101P. R. China
| | - You‐Qiang Su
- Shandong Provincial Key Laboratory of Animal Cells and Developmental BiologySchool of Life SciencesShandong UniversityQingdao266237P. R. China
- State Key Laboratory of Reproductive MedicineNanjing Medical UniversityNanjing211126P. R. China
- Collaborative Innovation Center of Genetics and DevelopmentFudan UniversityShanghai200433P. R. China
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11
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Layana C, Vilardo ES, Corujo G, Hernández G, Rivera-Pomar R. Drosophila Me31B is a Dual eIF4E-Interacting Protein. J Mol Biol 2023; 435:167949. [PMID: 36638908 DOI: 10.1016/j.jmb.2023.167949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/14/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) is a key factor involved in different aspects of mRNA metabolism. Drosophila melanogaster genome encodes eight eIF4E isoforms, and the canonical isoform eIF4E-1 is a ubiquitous protein that plays a key role in mRNA translation. eIF4E-3 is specifically expressed in testis and controls translation during spermatogenesis. In eukaryotic cells, translational control and mRNA decay is highly regulated in different cytoplasmic ribonucleoprotein foci, which include the processing bodies (PBs). In this study, we show that Drosophila eIF4E-1 and eIF4E-3 occur in PBs along the DEAD-box RNA helicase Me31B. We show that Me31B interacts with eIF4E-1 and eIF4E-3 by means of yeast two-hybrid system, FRET in D. melanogaster S2 cells and coimmunoprecipitation in testis. Truncation and point mutations of Me31B proteins show two eIF4E-binding sites located in different protein domains. Residues Y401-L407 (at the carboxy-terminus) are essential for interaction with eIF4E-1, whereas residues F63-L70 (at the amino-terminus) are critical for interaction with eIF4E-3. The residue W117 in eIF4E-1 and the homolog position F103 in eIF4E-3 are necessary for Me31B-eIF4E interaction suggesting that the change of tryptophan to phenylalanine provides specificity. Me31B represents a novel type of eIF4E-interacting protein with dual and specific interaction domains that might be recognized by different eIF4E isoforms in different tissues, adding complexity to the control of gene expression in eukaryotes.
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Affiliation(s)
- Carla Layana
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina.
| | - Emiliano Salvador Vilardo
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina
| | - Gonzalo Corujo
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina
| | - Greco Hernández
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, 14080 Mexico City, Mexico
| | - Rolando Rivera-Pomar
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina; Centro de Investigación y Transferencia del Noroeste de Buenos Aires (CITNOBA) - Centro de Bioinvestigaciones, Universidad Nacional del Noroeste de Buenos Aires, Av. Presidente Frondizi Km 4, 2700 Pergamino, Argentina; Molecular Developmental Biology Emeritus Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
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12
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Shih CY, Chen YC, Lin HY, Chu CY. RNA Helicase DDX6 Regulates A-to-I Editing and Neuronal Differentiation in Human Cells. Int J Mol Sci 2023; 24:ijms24043197. [PMID: 36834609 PMCID: PMC9965400 DOI: 10.3390/ijms24043197] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/24/2023] [Accepted: 01/31/2023] [Indexed: 02/09/2023] Open
Abstract
The DEAD-box proteins, one family of RNA-binding proteins (RBPs), participate in post-transcriptional regulation of gene expression with multiple aspects. Among them, DDX6 is an essential component of the cytoplasmic RNA processing body (P-body) and is involved in translational repression, miRNA-meditated gene silencing, and RNA decay. In addition to the cytoplasmic function, DDX6 is also present in the nucleus, but the nuclear function remains unknown. To decipher the potential role of DDX6 in the nucleus, we performed mass spectrometry analysis of immunoprecipitated DDX6 from a HeLa nuclear extract. We found that adenosine deaminases that act on RNA 1 (ADAR1) interact with DDX6 in the nucleus. Utilizing our newly developed dual-fluorescence reporter assay, we elucidated the DDX6 function as negative regulators in cellular ADAR1p110 and ADAR2. In addition, depletion of DDX6 and ADARs results in the opposite effect on facilitation of RA-induced differentiation of neuronal lineage cells. Our data suggest the impact of DDX6 in regulation of the cellular RNA editing level, thus contributing to differentiation in the neuronal cell model.
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Affiliation(s)
- Chia-Yu Shih
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Chi Chen
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Heng-Yi Lin
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chia-Ying Chu
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Center for Systems Biology, National Taiwan University, Taipei 10617, Taiwan
- Correspondence: ; Tel.: +886-2-33669876
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13
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Vijjamarri AK, Niu X, Vandermeulen MD, Onu C, Zhang F, Qiu H, Gupta N, Gaikwad S, Greenberg ML, Cullen PJ, Lin Z, Hinnebusch AG. Decapping factor Dcp2 controls mRNA abundance and translation to adjust metabolism and filamentation to nutrient availability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.05.522830. [PMID: 36711592 PMCID: PMC9881900 DOI: 10.1101/2023.01.05.522830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Degradation of most yeast mRNAs involves decapping by Dcp1/Dcp2. DEAD-box protein Dhh1 has been implicated as an activator of decapping, in coupling codon non-optimality to enhanced degradation, and as a translational repressor, but its functions in cells are incompletely understood. RNA-Seq analyses coupled with CAGE sequencing of all capped mRNAs revealed increased abundance of hundreds of mRNAs in dcp2 Δ cells that appears to result directly from impaired decapping rather than elevated transcription, which was confirmed by ChIP-Seq analysis of RNA Polymerase II occupancies genome-wide. Interestingly, only a subset of mRNAs requires Dhh1 for targeting by Dcp2, and also generally requires the other decapping activators Pat1, Lsm2, Edc3 or Scd6; whereas most of the remaining transcripts utilize NMD factors for Dcp2-mediated turnover. Neither inefficient translation initiation nor stalled elongation appears to be a major driver of Dhh1-enhanced mRNA degradation. Surprisingly, ribosome profiling revealed that dcp2 Δ confers widespread changes in relative TEs that generally favor well-translated mRNAs. Because ribosome biogenesis is reduced while capped mRNA abundance is increased by dcp2 Δ, we propose that an increased ratio of mRNA to ribosomes increases competition among mRNAs for limiting ribosomes to favor efficiently translated mRNAs in dcp2 Δ cells. Interestingly, genes involved in respiration or utilization of alternative carbon or nitrogen sources are derepressed, and both mitochondrial function and cell filamentation (a strategy for nutrient foraging) are elevated by dcp2 Δ, suggesting that mRNA decapping sculpts gene expression post-transcriptionally to fine-tune metabolic pathways and morphological transitions according to nutrient availability.
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Affiliation(s)
- Anil Kumar Vijjamarri
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Xiao Niu
- Department of Biology, Saint Louis University, St. Louis, MO
| | | | - Chisom Onu
- Department of Biological Sciences, Wayne State University, Detroit, MI
| | - Fan Zhang
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Hongfang Qiu
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Neha Gupta
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Swati Gaikwad
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | | | - Paul J Cullen
- Department of Biological Sciences, State University of Buffalo, Buffalo, NY
| | - Zhenguo Lin
- Department of Biology, Saint Louis University, St. Louis, MO
| | - Alan G Hinnebusch
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
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14
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Kim J, Muraoka M, Okada H, Toyoda A, Ajima R, Saga Y. The RNA helicase DDX6 controls early mouse embryogenesis by repressing aberrant inhibition of BMP signaling through miRNA-mediated gene silencing. PLoS Genet 2022; 18:e1009967. [PMID: 36197846 PMCID: PMC9534413 DOI: 10.1371/journal.pgen.1009967] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 08/11/2022] [Indexed: 11/29/2022] Open
Abstract
The evolutionarily conserved RNA helicase DDX6 is a central player in post-transcriptional regulation, but its role during embryogenesis remains elusive. We here show that DDX6 enables proper cell lineage specification from pluripotent cells by analyzing Ddx6 knockout (KO) mouse embryos and employing an in vitro epiblast-like cell (EpiLC) induction system. Our study unveils that DDX6 is an important BMP signaling regulator. Deletion of Ddx6 causes the aberrant upregulation of the negative regulators of BMP signaling, which is accompanied by enhanced expression of Nodal and related genes. Ddx6 KO pluripotent cells acquire higher pluripotency with a strong inclination toward neural lineage commitment. During gastrulation, abnormally expanded Nodal and Eomes expression in the primitive streak likely promotes endoderm cell fate specification while inhibiting mesoderm differentiation. We also genetically dissected major DDX6 pathways by generating Dgcr8, Dcp2, and Eif4enif1 KO models in addition to Ddx6 KO. We found that the miRNA pathway mutant Dgcr8 KO phenocopies Ddx6 KO, indicating that DDX6 mostly works along with the miRNA pathway during early development, whereas its P-body-related functions are dispensable. Therefore, we conclude that DDX6 prevents aberrant upregulation of BMP signaling inhibitors by participating in miRNA-mediated gene silencing processes. Overall, this study delineates how DDX6 affects the development of the three primary germ layers during early mouse embryogenesis and the underlying mechanism of DDX6 function.
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Affiliation(s)
- Jessica Kim
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Masafumi Muraoka
- Mammalian Development Laboratory, Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
| | - Hajime Okada
- Mammalian Development Laboratory, Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
| | - Atsushi Toyoda
- Advanced Genomics Center, National Institute of Genetics, Mishima, Japan
| | - Rieko Ajima
- Mammalian Development Laboratory, Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
- Department of Genetics, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Japan
- * E-mail: (RA); (YS)
| | - Yumiko Saga
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Mammalian Development Laboratory, Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
- Department of Genetics, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Japan
- * E-mail: (RA); (YS)
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15
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Wang D, Shalamberidze A, Arguello AE, Purse BW, Kleiner RE. Live-Cell RNA Imaging with Metabolically Incorporated Fluorescent Nucleosides. J Am Chem Soc 2022; 144:14647-14656. [PMID: 35930766 PMCID: PMC9940818 DOI: 10.1021/jacs.2c04142] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorescence imaging is a powerful method for probing macromolecular dynamics in biological systems; however, approaches for cellular RNA imaging are limited to the investigation of individual RNA constructs or bulk RNA labeling methods compatible primarily with fixed samples. Here, we develop a platform for fluorescence imaging of bulk RNA dynamics in living cells. We show that fluorescent bicyclic and tricyclic cytidine analogues can be metabolically incorporated into cellular RNA by overexpression of uridine-cytidine kinase 2. In particular, metabolic feeding with the tricyclic cytidine-derived nucleoside tC combined with confocal imaging enables the investigation of RNA synthesis, degradation, and trafficking at single-cell resolution. We apply our imaging modality to study RNA metabolism and localization during the oxidative stress response and find that bulk RNA turnover is greatly accelerated upon NaAsO2 treatment. Furthermore, we identify cytoplasmic RNA granules containing RNA transcripts generated during oxidative stress that are distinct from canonical stress granules and P-bodies and co-localize with the RNA helicase DDX6. Taken together, our work provides a powerful approach for live-cell RNA imaging and reveals how cells reshape RNA transcriptome dynamics in response to oxidative stress.
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Affiliation(s)
- Danyang Wang
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Ana Shalamberidze
- Department of Chemistry and Biochemistry and the Viral Information Institute, San Diego State University, San Diego, CA 92182, USA
| | | | - Byron W. Purse
- Department of Chemistry and Biochemistry and the Viral Information Institute, San Diego State University, San Diego, CA 92182, USA
| | - Ralph E. Kleiner
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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16
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Jamieson-Lucy AH, Kobayashi M, James Aykit Y, Elkouby YM, Escobar-Aguirre M, Vejnar CE, Giraldez AJ, Mullins MC. A proteomics approach identifies novel resident zebrafish Balbiani body proteins Cirbpa and Cirbpb. Dev Biol 2022; 484:1-11. [PMID: 35065906 PMCID: PMC8967276 DOI: 10.1016/j.ydbio.2022.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 01/17/2023]
Abstract
The Balbiani body (Bb) is the first marker of polarity in vertebrate oocytes. The Bb is a conserved structure found in diverse animals including insects, fish, amphibians, and mammals. During early zebrafish oogenesis, the Bb assembles as a transient aggregate of mRNA, proteins, and membrane-bound organelles at the presumptive vegetal side of the oocyte. As the early oocyte develops, the Bb appears to grow slowly, until at the end of stage I of oogenesis it disassembles and deposits its cargo of localized mRNAs and proteins. In fish and frogs, this cargo includes the germ plasm as well as gene products required to specify dorsal tissues of the future embryo. We demonstrate that the Bb is a stable, solid structure that forms a size exclusion barrier similar to other biological hydrogels. Despite its central role in oocyte polarity, little is known about the mechanism behind the Bb's action. Analysis of the few known protein components of the Bb is insufficient to explain how the Bb assembles, translocates, and disassembles. We isolated Bbs from zebrafish oocytes and performed mass spectrometry to define the Bb proteome. We successfully identified 77 proteins associated with the Bb sample, including known Bb proteins and novel RNA-binding proteins. In particular, we identified Cirbpa and Cirbpb, which have both an RNA-binding domain and a predicted self-aggregation domain. In stage I oocytes, Cirbpa and Cirbpb localize to the Bb rather than the nucleus (as in somatic cells), indicating that they may have a specialized function in the germ line. Both the RNA-binding domain and the self-aggregation domain are sufficient to localize to the Bb, suggesting that Cirbpa and Cirbpb interact with more than just their mRNA targets within the Bb. We propose that Cirbp proteins crosslink mRNA cargo and proteinaceous components of the Bb as it grows. Beyond Cirbpa and Cirbpb, our proteomics dataset presents many candidates for further study, making it a valuable resource for building a comprehensive mechanism for Bb function at a protein level.
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Affiliation(s)
- Allison H Jamieson-Lucy
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Manami Kobayashi
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Y James Aykit
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Yaniv M Elkouby
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Matias Escobar-Aguirre
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Charles E Vejnar
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Antonio J Giraldez
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Mary C Mullins
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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17
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Abstract
The 5'-terminal cap is a fundamental determinant of eukaryotic gene expression which facilitates cap-dependent translation and protects mRNAs from exonucleolytic degradation. Enzyme-directed hydrolysis of the cap (decapping) decisively affects mRNA expression and turnover, and is a heavily regulated event. Following the identification of the decapping holoenzyme (Dcp1/2) over two decades ago, numerous studies revealed the complexity of decapping regulation across species and cell types. A conserved set of Dcp1/2-associated proteins, implicated in decapping activation and molecular scaffolding, were identified through genetic and molecular interaction studies, and yet their exact mechanisms of action are only emerging. In this review, we discuss the prevailing models on the roles and assembly of decapping co-factors, with considerations of conservation across species and comparison across physiological contexts. We next discuss the functional convergences of decapping machineries with other RNA-protein complexes in cytoplasmic P bodies and compare current views on their impact on mRNA stability and translation. Lastly, we review the current models of decapping activation and highlight important gaps in our current understanding.
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Affiliation(s)
- Elva Vidya
- Goodman Cancer Institute, McGill University, Montréal, QC, Canada
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Thomas F. Duchaine
- Goodman Cancer Institute, McGill University, Montréal, QC, Canada
- Department of Biochemistry, McGill University, Montréal, QC, Canada
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18
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Weis K, Hondele M. The Role of DEAD-Box ATPases in Gene Expression and the Regulation of RNA-Protein Condensates. Annu Rev Biochem 2022; 91:197-219. [PMID: 35303788 DOI: 10.1146/annurev-biochem-032620-105429] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DEAD-box ATPases constitute a very large protein family present in all cells, often in great abundance. From bacteria to humans, they play critical roles in many aspects of RNA metabolism, and due to their widespread importance in RNA biology, they have been characterized in great detail at both the structural and biochemical levels. DEAD-box proteins function as RNA-dependent ATPases that can unwind short duplexes of RNA, remodel ribonucleoprotein (RNP) complexes, or act as clamps to promote RNP assembly. Yet, it often remains enigmatic how individual DEAD-box proteins mechanistically contribute to specific RNA-processing steps. Here, we review the role of DEAD-box ATPases in the regulation of gene expression and propose that one common function of these enzymes is in the regulation of liquid-liquid phase separation of RNP condensates. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Karsten Weis
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland;
| | - Maria Hondele
- Biozentrum, University of Basel, Basel, Switzerland;
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19
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Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the largest RNA genome, approximately 30 kb, among RNA viruses. The DDX DEAD box RNA helicase is a multifunctional protein involved in all aspects of RNA metabolism. Therefore, host RNA helicases may regulate and maintain such a large viral RNA genome. In this study, I investigated the potential role of several host cellular RNA helicases in SARS-CoV-2 infection. Notably, DDX21 knockdown markedly accumulated intracellular viral RNA and viral production, as well as viral infectivity of SARS-CoV-2, indicating that DDX21 strongly restricts the SARS-CoV-2 infection. In addition, MOV10 RNA helicase also suppressed the SARS-CoV-2 infection. In contrast, DDX1, DDX5, and DDX6 RNA helicases were required for SARS-CoV-2 replication. Indeed, SARS-CoV-2 infection dispersed the P-body formation of DDX6 and MOV10 RNA helicases as well as XRN1 exonuclease, while the viral infection did not induce stress granule formation. Accordingly, the SARS-CoV-2 nucleocapsid (N) protein interacted with DDX1, DDX3, DDX5, DDX6, DDX21, and MOV10 and disrupted the P-body formation, suggesting that SARS-CoV-2 N hijacks DDX6 to carry out viral replication. Conversely, DDX21 and MOV10 restricted SARS-CoV-2 infection through an interaction of SARS-CoV-2 N with host cellular RNA helicases. Altogether, host cellular RNA helicases seem to regulate the SARS-CoV-2 infection. IMPORTANCE SARS-CoV-2 has a large RNA genome, of approximately 30 kb. To regulate and maintain such a large viral RNA genome, host RNA helicases may be involved in SARS-CoV-2 replication. In this study, I have demonstrated that DDX21 and MOV10 RNA helicases limit viral infection and replication. In contrast, DDX1, DDX5, and DDX6 are required for SARS-CoV-2 infection. Interestingly, SARS-CoV-2 infection disrupted P-body formation and attenuated or suppressed stress granule formation. Thus, SARS-CoV-2 seems to hijack host cellular RNA helicases to play a proviral role by facilitating viral infection and replication and by suppressing the host innate immune system.
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20
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Dwivedi M, Laddha NC, Begum R. The Immunogenetics of Vitiligo: An Approach Toward Revealing the Secret of Depigmentation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1367:61-103. [PMID: 35286692 DOI: 10.1007/978-3-030-92616-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vitiligo is a hypomelanotic skin disease and considered to be of autoimmune origin due to breaching of immunological self-tolerance, resulting in inappropriate immune responses against melanocytes. The development of vitiligo includes a strong heritable component. Different strategies ranging from linkage studies to genome-wide association studies are used to explore the genetic factors responsible for the disease. Several vitiligo loci containing the respective genes have been identified which contribute to vitiligo and genetic variants for some of the genes are still unknown. These genes include mainly the proteins that play a role in immune regulation and a few other genes important for apoptosis and regulation of melanocyte functions. Despite the available data on genetic variants and risk alleles which influence the biological processes, only few immunological pathways have been found responsible for all ranges of severity and clinical manifestations of vitiligo. However, studies have concluded that vitiligo is of autoimmune origin and manifests due to complex interactions in immune components and their inappropriate response toward melanocytes. The genes involved in the immune regulation and processing the melanocytes antigen and its presentation can serve as effective immune-therapeutics that can target specific immunological pathways involved in vitiligo. This chapter highlights those immune-regulatory genes involved in vitiligo susceptibility and loci identified to date and their implications in vitiligo pathogenesis.
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Affiliation(s)
- Mitesh Dwivedi
- C. G. Bhakta Institute of Biotechnology, Uka Tarsadia University, Tarsadi, Surat, 394350, Gujarat, India.
| | - Naresh C Laddha
- In Vitro Specialty Lab Pvt. Ltd, 205-210, Golden Triangle, Navrangpura, Ahmedabad, 380009, Gujarat, India
| | - Rasheedunnisa Begum
- Department of Biochemistry, The Maharaja Sayajirao University of Baroda, Vadodara, 390002, Gujarat, India
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21
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Xu X, Wang J, Zhang Y, Yan Y, Liu Y, Shi X, Zhang Q. Inhibition of DDX6 enhances autophagy and alleviates endoplasmic reticulum stress in Vero cells under PEDV infection. Vet Microbiol 2022; 266:109350. [DOI: 10.1016/j.vetmic.2022.109350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 11/30/2022]
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22
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Zhang Y, Wang K, Yang K, Shi Y, Hong J. Insight into the interaction between the RNA helicase CGH-1 and EDC-3 and its implications. Sci Rep 2021; 11:20359. [PMID: 34645931 PMCID: PMC8514580 DOI: 10.1038/s41598-021-99919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 09/30/2021] [Indexed: 12/03/2022] Open
Abstract
Previous studies indicated that the P-body components, CGH-1 and EDC-3 may play a crucial role in the regulation of lifespan in Caenorhabditis elegans. Homo sapiens DDX6 or Saccharomyces cerevisiae Dhh1p (CGH-1 in C. elegans) could form complexes with EDC3 (Edc3p in yeast), respectively, which is significant for translation inhibition and mRNA decay. However, it is currently unclear how CGH-1 can be recognized by EDC-3 in C. elegans. Here, we provided structural and biochemical insights into the interaction between CGH-1 and EDC-3. Combined with homology modeling, mutation, and ITC assays, we uncovered an interface between CGH-1 RecA2 domain and EDC-3 FDF-FEK. Additionally, GST-pulldown and co-localization experiments confirmed the interaction between CGH-1 and EDC-3 in vitro and in vivo. We also analyzed PATR-1-binding interface on CGH-1 RecA2 by ITC assays. Moreover, we unveiled the similarity and differences of the binding mode between EDC-3 and CAR-1 or PATR-1. Taken together, these findings provide insights into the recognition of DEAD-box protein CGH-1 by EDC-3 FDF-FEK motif, suggesting important functional implications.
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Affiliation(s)
- Yong Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
- Ministry of Education Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Ke Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
- Ministry of Education Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Kanglong Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
- Ministry of Education Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Yunyu Shi
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China
- Ministry of Education Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Jingjun Hong
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, Anhui, People's Republic of China.
- Ministry of Education Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, Hefei, People's Republic of China.
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23
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Spendier K, Olesnicky EC, Forand D, Wolf M, Killian DJ. CPB-3 and CGH-1 localize to motile particles within dendrites in C. elegans PVD sensory neurons. BMC Res Notes 2021; 14:311. [PMID: 34391474 PMCID: PMC8364092 DOI: 10.1186/s13104-021-05730-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/04/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE RNA-binding proteins (RBPs) are important regulators of gene expression that influence mRNA splicing, stability, localization, transport, and translational control. In particular, RBPs play an important role in neurons, which have a complex morphology. Previously, we showed that there are many RBPs that play a conserved role in dendrite development in Drosophila dendritic arborization neurons and Caenorhabditis elegans (C. elegans) PVD neurons including the cytoplasmic polyadenylation element binding proteins (CPEBs), Orb in Drosophila and CPB-3 in C. elegans, and the DEAD box RNA helicases, Me31B in Drosophila and CGH-1 in C. elegans. During these studies, we observed that fluorescently-labeled CPB-3 and CGH-1 localize to cytoplasmic particles that are motile, and our research aims to further characterize these RBP-containing particles in live neurons. RESULTS Here we extend on previous work to show that CPB-3 and CGH-1 localize to motile particles within dendrites that move at a speed consistent with microtubule-based transport. This is consistent with a model in which CPB-3 and CGH-1 influence dendrite development through the transport and localization of their mRNA targets. Moreover, CPB-3 and CGH-1 rarely localize to the same particles suggesting that these RBPs function in discrete ribonucleoprotein particles (RNPs) that may regulate distinct mRNAs.
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Affiliation(s)
- Kathrin Spendier
- Physics Department and Center for the Biofrontiers Institute, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA.
| | - Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA.
| | - Daniel Forand
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA
| | - Margaret Wolf
- Department of Molecular Biology, Colorado College, Colorado Springs, CO, 80903, USA
| | - Darrell J Killian
- Department of Molecular Biology, Colorado College, Colorado Springs, CO, 80903, USA.
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24
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Sergeeva O, Zatsepin T. RNA Helicases as Shadow Modulators of Cell Cycle Progression. Int J Mol Sci 2021; 22:2984. [PMID: 33804185 PMCID: PMC8001981 DOI: 10.3390/ijms22062984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/06/2021] [Accepted: 03/10/2021] [Indexed: 02/07/2023] Open
Abstract
The progress of the cell cycle is directly regulated by modulation of cyclins and cyclin-dependent kinases. However, many proteins that control DNA replication, RNA transcription and the synthesis and degradation of proteins can manage the activity or levels of master cell cycle regulators. Among them, RNA helicases are key participants in RNA metabolism involved in the global or specific tuning of cell cycle regulators at the level of transcription and translation. Several RNA helicases have been recently evaluated as promising therapeutic targets, including eIF4A, DDX3 and DDX5. However, targeting RNA helicases can result in side effects due to the influence on the cell cycle. In this review, we discuss direct and indirect participation of RNA helicases in the regulation of the cell cycle in order to draw attention to downstream events that may occur after suppression or inhibition of RNA helicases.
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Affiliation(s)
- Olga Sergeeva
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30b1, 121205 Moscow, Russia;
| | - Timofei Zatsepin
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30b1, 121205 Moscow, Russia;
- Department of Chemistry, Lomonosov Moscow State University, 119992 Moscow, Russia
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25
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Nguyen DND, Chilian WM, Zain SM, Daud MF, Pung YF. MicroRNA regulation of vascular smooth muscle cells and its significance in cardiovascular diseases. Can J Physiol Pharmacol 2021; 99:827-838. [PMID: 33529092 DOI: 10.1139/cjpp-2020-0581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cardiovascular disease (CVD) is among the leading causes of death worldwide. MicroRNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification, and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs is also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages are discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression, and (or) miRNA-derived therapeutic approaches in CVD research.
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Affiliation(s)
- Duong Ngoc Diem Nguyen
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Semenyih, 43500 Selangor, Malaysia
| | - William M Chilian
- Integrative Medical Sciences, Northeast Ohio Medical University, 4209 St. Rt. 44, P.O. Box 95, Rootstown, OH P.O. Box 95, USA
| | - Shamsul Mohd Zain
- The Pharmacogenomics Laboratory, Department of Pharmacology, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Muhammad Fauzi Daud
- Institute of Medical Science Technology, Universiti Kuala Lumpur, Kajang, 43000 Selangor, Malaysia
| | - Yuh-Fen Pung
- Division of Biomedical Science, School of Pharmacy, University of Nottingham Malaysia, Semenyih, 43500 Selangor, Malaysia
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26
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Wang J, Li T, Deng S, Ma E, Zhang J, Xing S. DDX6 Is Essential for Oocyte Development and Maturation in Locusta migratoria. INSECTS 2021; 12:70. [PMID: 33466820 PMCID: PMC7830464 DOI: 10.3390/insects12010070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 11/16/2022]
Abstract
DEAD-box protein 6 (DDX6) is a member of the DDX RNA helicase family that exists in all eukaryotes. It has been extensively studied in yeast and mammals and has been shown to be involved in messenger ribonucleoprotein assembly, mRNA storage, and decay, as well as in miRNA-mediated gene silencing. DDX6 participates in many developmental processes but the biological function of DDX6 in insects has not yet been adequately addressed. Herein, we characterized the LmDDX6 gene that encodes the LmDDX6 protein in Locusta migratoria, a global, destructive pest. LmDDX6 possesses five motifs unique to the DDX6 subfamily. In the phylogenetic tree, LmDDX6 was closely related to its orthologs in Apis dorsata and Zootermopsis nevadensis. RT-qPCR data revealed high expression of LmDDX6 in the ovary, muscle, and fat body, with a declining trend in the ovary after adult ecdysis. LmDDX6 knockdown downregulated the expression levels of the juvenile hormone receptor Met, and genes encoding Met downstream targeted Grp78-1 and Grp78-2, reduced LmVg expression, and impaired ovary development and oocyte maturation. These results demonstrate that LmDDX6 plays an essential role in locust female reproduction and, thus, could be a novel target for locust biological control.
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Affiliation(s)
- Junxiu Wang
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- College of Life Science, Shanxi University, Taiyuan 030006, Shanxi, China
| | - Tingting Li
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- College of Life Science, Shanxi University, Taiyuan 030006, Shanxi, China
| | - Sufang Deng
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- College of Life Science, Shanxi University, Taiyuan 030006, Shanxi, China
- College of Biological Sciences and Technology, Jinzhong University, Jinzhong 030600, Shanxi, China
| | - Enbo Ma
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- Shanxi Provincial Key Laboratory of Agricultural Integrated Pest Management, Taiyuan 030006, Shanxi, China
| | - Jianzhen Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- Shanxi Provincial Key Laboratory of Agricultural Integrated Pest Management, Taiyuan 030006, Shanxi, China
| | - Shuping Xing
- Research Institute of Applied Biology, Shanxi University, Taiyuan 030006, Shanxi, China; (J.W.); (T.L.); (S.D.); (E.M.); (J.Z.)
- Shanxi Provincial Key Laboratory of Agricultural Integrated Pest Management, Taiyuan 030006, Shanxi, China
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Christou-Kent M, Dhellemmes M, Lambert E, Ray PF, Arnoult C. Diversity of RNA-Binding Proteins Modulating Post-Transcriptional Regulation of Protein Expression in the Maturing Mammalian Oocyte. Cells 2020; 9:cells9030662. [PMID: 32182827 PMCID: PMC7140715 DOI: 10.3390/cells9030662] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 12/18/2022] Open
Abstract
The oocyte faces a particular challenge in terms of gene regulation. When oocytes resume meiosis at the end of the growth phase and prior to ovulation, the condensed chromatin state prevents the transcription of genes as they are required. Transcription is effectively silenced from the late germinal vesicle (GV) stage until embryonic genome activation (EGA) following fertilisation. Therefore, during its growth, the oocyte must produce the mRNA transcripts needed to fulfil its protein requirements during the active period of meiotic completion, fertilisation, and the maternal-to zygote-transition (MZT). After meiotic resumption, gene expression control can be said to be transferred from the nucleus to the cytoplasm, from transcriptional regulation to translational regulation. Maternal RNA-binding proteins (RBPs) are the mediators of translational regulation and their role in oocyte maturation and early embryo development is vital. Understanding these mechanisms will provide invaluable insight into the oocyte's requirements for developmental competence, with important implications for the diagnosis and treatment of certain types of infertility. Here, we give an overview of post-transcriptional regulation in the oocyte, emphasising the current knowledge of mammalian RBP mechanisms, and develop the roles of these mechanisms in the timely activation and elimination of maternal transcripts.
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Affiliation(s)
- Marie Christou-Kent
- Université Grenoble Alpes, F-38000 Grenoble, France; (M.C.-K.); (M.D.); (E.L.); (P.F.R.)
- Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Magali Dhellemmes
- Université Grenoble Alpes, F-38000 Grenoble, France; (M.C.-K.); (M.D.); (E.L.); (P.F.R.)
- Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Emeline Lambert
- Université Grenoble Alpes, F-38000 Grenoble, France; (M.C.-K.); (M.D.); (E.L.); (P.F.R.)
- Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
| | - Pierre F. Ray
- Université Grenoble Alpes, F-38000 Grenoble, France; (M.C.-K.); (M.D.); (E.L.); (P.F.R.)
- Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
- CHU de Grenoble, UM GI-DPI, F-38000 Grenoble, France
| | - Christophe Arnoult
- Université Grenoble Alpes, F-38000 Grenoble, France; (M.C.-K.); (M.D.); (E.L.); (P.F.R.)
- Institute for Advanced Biosciences INSERM U1209, CNRS UMR5309, F-38000 Grenoble, France
- Correspondence: ; Tel.: +33-(0)4-76-63-74-08
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28
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Wilczynska A, Gillen SL, Schmidt T, Meijer HA, Jukes-Jones R, Langlais C, Kopra K, Lu WT, Godfrey JD, Hawley BR, Hodge K, Zanivan S, Cain K, Le Quesne J, Bushell M. eIF4A2 drives repression of translation at initiation by Ccr4-Not through purine-rich motifs in the 5'UTR. Genome Biol 2019; 20:262. [PMID: 31791371 PMCID: PMC6886185 DOI: 10.1186/s13059-019-1857-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 10/10/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Regulation of the mRNA life cycle is central to gene expression control and determination of cell fate. miRNAs represent a critical mRNA regulatory mechanism, but despite decades of research, their mode of action is still not fully understood. RESULTS Here, we show that eIF4A2 is a major effector of the repressive miRNA pathway functioning via the Ccr4-Not complex. We demonstrate that while DDX6 interacts with Ccr4-Not, its effects in the mechanism are not as pronounced. Through its interaction with the Ccr4-Not complex, eIF4A2 represses mRNAs at translation initiation. We show evidence that native eIF4A2 has similar RNA selectivity to chemically inhibited eIF4A1. eIF4A2 exerts its repressive effect by binding purine-rich motifs which are enriched in the 5'UTR of target mRNAs directly upstream of the AUG start codon. CONCLUSIONS Our data support a model whereby purine motifs towards the 3' end of the 5'UTR are associated with increased ribosome occupancy and possible uORF activation upon eIF4A2 binding.
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Affiliation(s)
- Ania Wilczynska
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
| | - Sarah L Gillen
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Tobias Schmidt
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Hedda A Meijer
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
- Present Address: Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | | | | | - Kari Kopra
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
- Present Address: Department of Chemistry, University of Turku, Vatselankatu 2, FI-20500, Turku, Finland
| | - Wei-Ting Lu
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Jack D Godfrey
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | | | - Kelly Hodge
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Kelvin Cain
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - John Le Quesne
- MRC Toxicology Unit, Lancaster Road, Leicester, LE1 9HN, UK
| | - Martin Bushell
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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Cytolethal distending toxin induces the formation of transient messenger-rich ribonucleoprotein nuclear invaginations in surviving cells. PLoS Pathog 2019; 15:e1007921. [PMID: 31568537 PMCID: PMC6824578 DOI: 10.1371/journal.ppat.1007921] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 11/01/2019] [Accepted: 06/18/2019] [Indexed: 01/26/2023] Open
Abstract
Humans are frequently exposed to bacterial genotoxins involved in digestive cancers, colibactin and Cytolethal Distending Toxin (CDT), the latter being secreted by many pathogenic bacteria. Our aim was to evaluate the effects induced by these genotoxins on nuclear remodeling in the context of cell survival. Helicobacter infected mice, coculture experiments with CDT- and colibactin-secreting bacteria and hepatic, intestinal and gastric cells, and xenograft mouse-derived models were used to assess the nuclear remodeling in vitro and in vivo. Our results showed that CDT and colibactin induced-nuclear remodeling can be associated with the formation of deep cytoplasmic invaginations in the nucleus of giant cells. These structures, observed both in vivo and in vitro, correspond to nucleoplasmic reticulum (NR). The core of the NR was found to concentrate ribosomes, proteins involved in mRNA translation, polyadenylated RNA and the main components of the complex mCRD involved in mRNA turnover. These structures are active sites of mRNA translation, correlated with a high degree of ploidy, and involve MAPK and calcium signaling. Additional data showed that insulation and concentration of these adaptive ribonucleoprotein particles within the nucleus are dynamic, transient and protect the cell until the genotoxic stress is relieved. Bacterial genotoxins-induced NR would be a privileged gateway for selected mRNA to be preferably transported therein for local translation. These findings offer new insights into the context of NR formation, a common feature of many cancers, which not only appears in response to therapies-induced DNA damage but also earlier in response to genotoxic bacteria. Humans are frequently exposed to bacterial genotoxins linked to cancers, colibactin and Cytolethal Distending Toxin (CDT). These genotoxins induce DNA damage and can promote formation of nucleoplasmic reticulum (NR), deeply invaginated in the nucleoplasm of giant nuclei both in vivo and in vitro. Our cellular models showed that these structures can be observed together with profound nuclear reorganization corresponding to remodeling of nuclear material. The core of the genotoxin-induced NRs concentrates protein production machinery of the cell as well as controlling elements of protein turnover. These genotoxin-induced dynamic structures may also be signaling hubs controlling mRNA turnover and translation of selected mRNAs and thus correspond to a privileged gateway for the synthesis of selected mRNA which are preferentially transported from the nucleus through pores and translated therein. These transient and reversible hubs allow the cell to pause and repair the DNA damage caused by bacterial genotoxins in order to maintain cell survival. As NR formation is a common feature of many cancers, similar mechanism could occur and contribute to the resistance of cancer cells to radiotherapies and some chemotherapies aimed at inducing DNA damage.
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30
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Zeidan Q, He F, Zhang F, Zhang H, Jacobson A, Hinnebusch AG. Conserved mRNA-granule component Scd6 targets Dhh1 to repress translation initiation and activates Dcp2-mediated mRNA decay in vivo. PLoS Genet 2018; 14:e1007806. [PMID: 30532217 PMCID: PMC6307823 DOI: 10.1371/journal.pgen.1007806] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 12/27/2018] [Accepted: 11/02/2018] [Indexed: 12/21/2022] Open
Abstract
Scd6 protein family members are evolutionarily conserved components of translationally silent mRNA granules. Yeast Scd6 interacts with Dcp2 and Dhh1, respectively a subunit and a regulator of the mRNA decapping enzyme, and also associates with translation initiation factor eIF4G to inhibit translation in cell extracts. However, the role of Scd6 in mRNA turnover and translational repression in vivo is unclear. We demonstrate that tethering Scd6 to a GFP reporter mRNA reduces mRNA abundance via Dcp2 and suppresses reporter mRNA translation via Dhh1. Thus, in a dcp2Δ mutant, tethered Scd6 reduces GFP protein expression with little effect on mRNA abundance, whereas tethered Scd6 has no impact on GFP protein or mRNA expression in a dcp2Δ dhh1Δ double mutant. The conserved LSm domain of Scd6 is required for translational repression and mRNA turnover by tethered Scd6. Both functions are enhanced in a ccr4Δ mutant, suggesting that the deadenylase function of Ccr4-Not complex interferes with a more efficient repression pathway enlisted by Scd6. Ribosome profiling and RNA-Seq analysis of scd6Δ and dhh1Δ mutants suggests that Scd6 cooperates with Dhh1 in translational repression and turnover of particular native mRNAs, with both processes dependent on Dcp2. Our results suggest that Scd6 can (i) recruit Dhh1 to confer translational repression and (ii) activate mRNA decapping by Dcp2 with attendant degradation of specific mRNAs in vivo, in a manner dependent on the Scd6 LSm domain and modulated by Ccr4.
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Affiliation(s)
- Quira Zeidan
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Feng He
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Fan Zhang
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Hongen Zhang
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Alan G. Hinnebusch
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, United States of America
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31
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DeHaan H, McCambridge A, Armstrong B, Cruse C, Solanki D, Trinidad JC, Arkov AL, Gao M. An in vivo proteomic analysis of the Me31B interactome in Drosophila germ granules. FEBS Lett 2017; 591:3536-3547. [PMID: 28945271 DOI: 10.1002/1873-3468.12854] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/07/2017] [Accepted: 09/15/2017] [Indexed: 12/11/2022]
Abstract
Drosophila Me31B is a conserved protein of germ granules, ribonucleoprotein complexes essential for germ cell development. Me31B post-transcriptionally regulates mRNAs by interacting with other germ granule proteins. However, a Me31B interactome is lacking. Here, we use an in vivo proteomics approach to show that the Me31B interactome contains polypeptides from four functional groups: RNA regulatory proteins, glycolytic enzymes, cytoskeleton/motor proteins, and germ plasm components. We further show that Me31B likely colocalizes with the germ plasm components Tudor (Tud), Vasa, and Aubergine in the nuage and germ plasm and provide evidence that Me31B may directly bind to Tud in a symmetrically dimethylated arginine-dependent manner. Our study supports the role of Me31B in RNA regulation and suggests its novel roles in germ granule assembly and function.
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Affiliation(s)
- Hunter DeHaan
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | | | - Carlie Cruse
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | - Dhruv Solanki
- Biology Department, Indiana University Northwest, Gary, IN, USA
| | | | - Alexey L Arkov
- Department of Biological Sciences, Murray State University, Murray, KY, USA
| | - Ming Gao
- Biology Department, Indiana University Northwest, Gary, IN, USA
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32
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Götze M, Dufourt J, Ihling C, Rammelt C, Pierson S, Sambrani N, Temme C, Sinz A, Simonelig M, Wahle E. Translational repression of the Drosophila nanos mRNA involves the RNA helicase Belle and RNA coating by Me31B and Trailer hitch. RNA (NEW YORK, N.Y.) 2017; 23:1552-1568. [PMID: 28701521 PMCID: PMC5602113 DOI: 10.1261/rna.062208.117] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/10/2017] [Indexed: 05/10/2023]
Abstract
Translational repression of maternal mRNAs is an essential regulatory mechanism during early embryonic development. Repression of the Drosophila nanos mRNA, required for the formation of the anterior-posterior body axis, depends on the protein Smaug binding to two Smaug recognition elements (SREs) in the nanos 3' UTR. In a comprehensive mass spectrometric analysis of the SRE-dependent repressor complex, we identified Smaug, Cup, Me31B, Trailer hitch, eIF4E, and PABPC, in agreement with earlier data. As a novel component, the RNA-dependent ATPase Belle (DDX3) was found, and its involvement in deadenylation and repression of nanos was confirmed in vivo. Smaug, Cup, and Belle bound stoichiometrically to the SREs, independently of RNA length. Binding of Me31B and Tral was also SRE-dependent, but their amounts were proportional to the length of the RNA and equimolar to each other. We suggest that "coating" of the RNA by a Me31B•Tral complex may be at the core of repression.
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Affiliation(s)
- Michael Götze
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Jérémy Dufourt
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Christian Ihling
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Christiane Rammelt
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Stephanie Pierson
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Nagraj Sambrani
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Claudia Temme
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Andrea Sinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Martine Simonelig
- Institute of Human Genetics, UMR9002 CNRS-University of Montpellier, 34396 Montpellier Cedex 5, France
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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33
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Jung D, Ahn J, Rhee B, Kim J. Mutational analysis of the RNA helicase Dhh1 in Ste12 expression and yeast mating. J Microbiol 2017; 55:373-378. [PMID: 28455591 DOI: 10.1007/s12275-017-7020-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/06/2017] [Accepted: 04/11/2017] [Indexed: 01/07/2023]
Abstract
Dhh1 and Dhh1 homologues (RCK/p54/DDX6) are members of the DEAD-box protein family of RNA helicases. These proteins display conserved sequence motifs for ATPase and RNA binding activities. Dhh1 is a component of the P-bodies (processing bodies) of mRNA granules and functions as an mRNA decapping activator in Saccharomyces cerevisiae. Dhh1 also contributes to gene-specific regulation during yeast mating. The dhh1 deletion mutation results in a significant decrease in the expression of Ste12, a mating-specific transcription factor, showing severe mating defects. Here, we introduced amino-acid substitution mutations in the ATPase and RNA binding domains of Dhh1 and also constructed a deletion of 79 amino acids at the Q/P-rich C-terminal region. The mutations in ATPase A and B motif (K96R, D195A) and C-terminus deletion showed reduced levels of mating efficiency as well as Ste12 protein expression. The Q/P-rich C-terminal region of Dhh1 was dispensable for growth at nonpermissive temperature 37°C but appeared to play an important role in regulating the Ste12 protein expression and mating processes. The P-body accumulation induced by treatment with α-mating factor required ATPase, RNA-binding and the Q/P-rich C-terminal domains of Dhh1.
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Affiliation(s)
- Daehee Jung
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jihye Ahn
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Boram Rhee
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jinmi Kim
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
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34
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Biegel JM, Henderson E, Cox EM, Bonenfant G, Netzband R, Kahn S, Eager R, Pager CT. Cellular DEAD-box RNA helicase DDX6 modulates interaction of miR-122 with the 5' untranslated region of hepatitis C virus RNA. Virology 2017; 507:231-241. [PMID: 28456022 DOI: 10.1016/j.virol.2017.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) subverts the cellular DEAD-box RNA helicase DDX6 to promote virus infection. Using polysome gradient analysis and the subgenomic HCV Renilla reporter replicon genome, we determined that DDX6 does not affect HCV translation. Rather expression of the subgenomic HCV Renilla luciferase reporter at late times, as well as labeling of newly synthesized viral RNA with 4-thiouridine showed that DDX6 modulates replication. Because DDX6 is an effector protein of the microRNA pathway, we also investigated its role in miR-122-directed HCV gene expression. Similar to sequestering miR-122, depletion of DDX6 modulated HCV RNA stability. Interestingly, miR-122-HCV RNA interaction assays with mutant HCV genomes sites and compensatory exogenous miR-122 showed that DDX6 affects the function of miR-122 at one particular binding site. We propose that DDX6 facilitates the miR-122 interaction with HCV 5' UTR, which is necessary for stabilizing the viral genome and the switch between translation and replication.
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Affiliation(s)
- Jason M Biegel
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Eric Henderson
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Erica M Cox
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gaston Bonenfant
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Rachel Netzband
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Samantha Kahn
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Rachel Eager
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Cara T Pager
- Department of Biological Sciences, The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
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Huang JH, Ku WC, Chen YC, Chang YL, Chu CY. Dual mechanisms regulate the nucleocytoplasmic localization of human DDX6. Sci Rep 2017; 7:42853. [PMID: 28216671 PMCID: PMC5316971 DOI: 10.1038/srep42853] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/18/2017] [Indexed: 12/14/2022] Open
Abstract
DDX6 is a conserved DEAD-box protein (DBP) that plays central roles in cytoplasmic RNA regulation, including processing body (P-body) assembly, mRNA decapping, and translational repression. Beyond its cytoplasmic functions, DDX6 may also have nuclear functions because its orthologues are known to localize to nuclei in several biological contexts. However, it is unclear whether DDX6 is generally present in human cell nuclei, and the molecular mechanism underlying DDX6 subcellular distribution remains elusive. In this study, we showed that DDX6 is commonly present in the nuclei of human-derived cells. Our structural and molecular analyses deviate from the current model that the shuttling of DDX6 is directly mediated by the canonical nuclear localization signal (NLS) and nuclear export signal (NES), which are recognized and transported by Importin-α/β and CRM1, respectively. Instead, we show that DDX6 can be transported by 4E-T in a piggyback manner. Furthermore, we provide evidence for a novel nuclear targeting mechanism in which DDX6 enters the newly formed nuclei by "hitch-hiking" on mitotic chromosomes with its C-terminal domain during M phase progression. Together, our results indicate that the nucleocytoplasmic localization of DDX6 is regulated by these dual mechanisms.
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Affiliation(s)
- Jo-Hsi Huang
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Chi Ku
- School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei 24205, Taiwan
| | - Yen-Chun Chen
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Ling Chang
- School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei 24205, Taiwan
| | - Chia-Ying Chu
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Center for Systems Biology, National Taiwan University, Taipei 10617, Taiwan
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Abstract
Fully grown oocytes arrest meiosis at prophase I and deposit maternal RNAs. A subset of maternal transcripts is stored in a dormant state in the oocyte, and the timely driven translation of specific mRNAs guides meiotic progression, the oocyte-embryo transition, and early embryo development. In the absence of transcription, the regulation of gene expression in oocytes is controlled almost exclusively at the level of transcriptome and proteome stabilization and at the level of protein synthesis.This chapter focuses on the recent findings on RNA distribution related to the temporal and spatial translational control of the meiotic cycle progression in mammalian oocytes. We discuss the most relevant mechanisms involved in the organization of the oocyte's maternal transcriptome storage and localization, and the regulation of translation, in correlation with the regulation of oocyte meiotic progression.
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Jungfleisch J, Blasco-Moreno B, Díez J. Use of Cellular Decapping Activators by Positive-Strand RNA Viruses. Viruses 2016; 8:v8120340. [PMID: 28009841 PMCID: PMC5192400 DOI: 10.3390/v8120340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/06/2016] [Accepted: 12/19/2016] [Indexed: 12/14/2022] Open
Abstract
Positive-strand RNA viruses have evolved multiple strategies to not only circumvent the hostile decay machinery but to trick it into being a priceless collaborator supporting viral RNA translation and replication. In this review, we describe the versatile interaction of positive-strand RNA viruses and the 5′-3′ mRNA decay machinery with a focus on the viral subversion of decapping activators. This highly conserved viral trickery is exemplified with the plant Brome mosaic virus, the animal Flock house virus and the human hepatitis C virus.
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Affiliation(s)
- Jennifer Jungfleisch
- Molecular Virology Laboratory, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona 08003, Spain.
| | - Bernat Blasco-Moreno
- Molecular Virology Laboratory, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona 08003, Spain.
| | - Juana Díez
- Molecular Virology Laboratory, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona 08003, Spain.
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The nucleolar helicase DDX56 redistributes to West Nile virus assembly sites. Virology 2016; 500:169-177. [PMID: 27821284 DOI: 10.1016/j.virol.2016.10.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 10/18/2016] [Accepted: 10/25/2016] [Indexed: 01/30/2023]
Abstract
Flaviviruses, including the human pathogen, West Nile virus (WNV), are known to co-opt many host factors for their replication and propagation. To this end, we previously reported that the nucleolar DEAD-box RNA helicase, DDX56, is important for production of infectious WNV virions. In this study, we show that WNV infection results in relocalization of DDX56 from nucleoli to virus assembly sites on the endoplasmic reticululm (ER), an observation that is consistent with a role for DDX56 in WNV virion assembly. Super-resolution microscopy revealed that capsid and DDX56 localized to the same subcompartment of the ER, however, unexpectedly, stable interaction between these two proteins was only detected in the nucleus. Together, these data suggest that DDX56 relocalizes to the site of virus assembly during WNV infection and that its interaction with WNV capsid in the cytoplasm may occur transiently during virion morphogenesis.
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Zampedri C, Tinoco-Cuellar M, Carrillo-Rosas S, Diaz-Tellez A, Ramos-Balderas JL, Pelegri F, Maldonado E. Zebrafish P54 RNA helicases are cytoplasmic granule residents that are required for development and stress resilience. Biol Open 2016; 5:1473-1484. [PMID: 27489304 PMCID: PMC5087673 DOI: 10.1242/bio.015826] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Stress granules are cytoplasmic foci that directly respond to the protein synthesis status of the cell. Various environmental insults, such as oxidative stress or extreme heat, block protein synthesis; consequently, mRNA will stall in translation, and stress granules will immediately form and become enriched with mRNAs. P54 DEAD box RNA helicases are components of RNA granules such as P-bodies and stress granules. We studied the expression, in cytoplasmic foci, of both zebrafish P54 RNA helicases (P54a and P54b) during development and found that they are expressed in cytoplasmic granules under both normal conditions and stress conditions. In zebrafish embryos exposed to heat shock, some proportion of P54a and P54b helicases move to larger granules that exhibit the properties of genuine stress granules. Knockdown of P54a and/or P54b in zebrafish embryos produces developmental abnormalities restricted to the posterior trunk; further, these embryos do not form stress granules, and their survival upon exposure to heat-shock conditions is compromised. Our observations fit the model that cells lacking stress granules have no resilience or ability to recover once the stress has ended, indicating that stress granules play an essential role in the way organisms adapt to a changing environment. Summary: Stress granules are formed by mRNAs stalled in translation during stress conditions. P54 RNA helicases from zebrafish reside in cytoplasmic granules and are essential for heat-shock resilience.
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Affiliation(s)
- Cecilia Zampedri
- EvoDevo Laboratory, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México, 77580
| | - Maryana Tinoco-Cuellar
- EvoDevo Laboratory, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México, 77580
| | - Samantha Carrillo-Rosas
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, D.F. México, México, 04510
| | - Abigail Diaz-Tellez
- EvoDevo Laboratory, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México, 77580
| | - Jose Luis Ramos-Balderas
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, D.F. México, México, 04510
| | - Francisco Pelegri
- Laboratory of Genetics, University of Wisconsin-Madison, Wisconsin 53706, USA
| | - Ernesto Maldonado
- EvoDevo Laboratory, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México, 77580
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Tuteja R. Emerging functions of helicases in regulation of stress survival in malaria parasite Plasmodium falciparum and their comparison with human host. Parasitol Int 2016; 65:645-664. [PMID: 27586396 DOI: 10.1016/j.parint.2016.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 06/28/2016] [Accepted: 08/28/2016] [Indexed: 02/04/2023]
Abstract
The cellular response to various stresses is a universal phenomenon and involves a common set of stress responses that are largely independent of the type of stress. The response to stress is complex and cells can activate multiple signaling pathways that act in concert to influence cell fate and results in a specific cellular outcome, including reduction in macromolecular synthesis by shared pathways, cell cycle arrest, DNA repair, senescence and/or apoptosis. Whether cells mount a protective response or die depends to a great degree on the nature and duration of the stress and the particular cell type. Helicases play essential roles in DNA replication, repair, recombination, transcription and translation, and also participate in RNA metabolic processes including pre-mRNA processing, ribosome biogenesis, RNA turnover, export, translation, surveillance, storage and decay. In order to survive in the human host, the malaria parasite Plasmodium falciparum has to handle variety of stresses, which it encounters during the erythrocytic stages of its life cycle. In recent past the role of helicases in imparting various stress responses has emerged. Therefore in the present review an attempt has been made to highlight the emerging importance of helicases in stress responses in malaria parasite and their comparison with human host is also presented. It is noteworthy that PfDHX33 and PfDDX60 are larger in size and different in sequence as compared to the HsDHX33 and HsDDX60. The study suggests that helicases are multifunctional and play major role in helping the cells to combat various stresses.
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Affiliation(s)
- Renu Tuteja
- Parasite Biology Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110067, India.
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41
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The multiple functions of RNA helicases as drivers and regulators of gene expression. Nat Rev Mol Cell Biol 2016; 17:426-38. [PMID: 27251421 DOI: 10.1038/nrm.2016.50] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RNA helicases comprise the largest family of enzymes involved in the metabolism of mRNAs, the processing and fate of which rely on their packaging into messenger ribonucleoprotein particles (mRNPs). In this Review, we describe how the capacity of some RNA helicases to either remodel or lock the composition of mRNP complexes underlies their pleiotropic functions at different steps of the gene expression process. We illustrate the roles of RNA helicases in coordinating gene expression steps and programmes, and propose that RNA helicases function as molecular drivers and guides of the progression of their mRNA substrates from one RNA-processing factory to another, to a productive mRNA pool that leads to protein synthesis or to unproductive mRNA pools that are stored or degraded.
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42
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Li J, Sen GL. Post-Transcriptional Mechanisms Regulating Epidermal Stem and Progenitor Cell Self-Renewal and Differentiation. J Invest Dermatol 2016; 136:746-752. [DOI: 10.1016/j.jid.2015.12.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/17/2015] [Accepted: 11/30/2015] [Indexed: 01/19/2023]
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43
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Shen C, Gao J, Sheng Y, Dou J, Zhou F, Zheng X, Ko R, Tang X, Zhu C, Yin X, Sun L, Cui Y, Zhang X. Genetic Susceptibility to Vitiligo: GWAS Approaches for Identifying Vitiligo Susceptibility Genes and Loci. Front Genet 2016; 7:3. [PMID: 26870082 PMCID: PMC4740779 DOI: 10.3389/fgene.2016.00003] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 01/11/2016] [Indexed: 01/15/2023] Open
Abstract
Vitiligo is an autoimmune disease with a strong genetic component, characterized by areas of depigmented skin resulting from loss of epidermal melanocytes. Genetic factors are known to play key roles in vitiligo through discoveries in association studies and family studies. Previously, vitiligo susceptibility genes were mainly revealed through linkage analysis and candidate gene studies. Recently, our understanding of the genetic basis of vitiligo has been rapidly advancing through genome-wide association study (GWAS). More than 40 robust susceptible loci have been identified and confirmed to be associated with vitiligo by using GWAS. Most of these associated genes participate in important pathways involved in the pathogenesis of vitiligo. Many susceptible loci with unknown functions in the pathogenesis of vitiligo have also been identified, indicating that additional molecular mechanisms may contribute to the risk of developing vitiligo. In this review, we summarize the key loci that are of genome-wide significance, which have been shown to influence vitiligo risk. These genetic loci may help build the foundation for genetic diagnosis and personalize treatment for patients with vitiligo in the future. However, substantial additional studies, including gene-targeted and functional studies, are required to confirm the causality of the genetic variants and their biological relevance in the development of vitiligo.
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Affiliation(s)
- Changbing Shen
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Jing Gao
- Department of Dermatology, The Second Affiliated Hospital, Anhui Medical University Hefei, China
| | - Yujun Sheng
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Jinfa Dou
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Fusheng Zhou
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Xiaodong Zheng
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Randy Ko
- Department of Biochemistry, University of New Mexico Albuquerque, NM, USA
| | - Xianfa Tang
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Caihong Zhu
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Xianyong Yin
- Department of Genetics and Renaissance Computing Institute, University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Liangdan Sun
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical University Hefei, China
| | - Yong Cui
- Department of Dermatology, China-Japan Friendship Hospital Beijing, China
| | - Xuejun Zhang
- Institute and Department of Dermatology, The First Affiliated Hospital, Anhui Medical UniversityHefei, China; Department of Dermatology, The Second Affiliated Hospital, Anhui Medical UniversityHefei, China
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Cho YJ, Kang W, Kim SH, Sa JK, Kim N, Paddison PJ, Kim M, Joo KM, Hwang YI, Nam DH. Involvement of DDX6 gene in radio- and chemoresistance in glioblastoma. Int J Oncol 2016; 48:1053-62. [PMID: 26783102 DOI: 10.3892/ijo.2016.3328] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/06/2015] [Indexed: 11/05/2022] Open
Abstract
CCRT (concomitant chemotherapy and radiation therapy) is often used for glioblastoma multiforme (GBM) treatment after surgical therapy, however, patients treated with CCRT undergo poor prognosis due to development of treatment resistant recurrence. Many studies have been performed to overcome these problems and to discover genes influencing treatment resistance. To discover potential genes inducing CCRT resistance in GBM, we used whole genome screening by infecting shRNA pool in patient-derived cell. The cells infected ~8,000 shRNAs were implanted in mouse brain and treated RT/TMZ as in CCRT treated patients. We found DDX6 as the candidate gene for treatment resistance after screening and establishing DDX6 knock down cells for functional validation. Using these cells, we confirmed tumor associated ability of DDX6 in vitro and in vivo. Although proliferation improvement was not found, decreased DDX6 influenced upregulated clonogenic ability and resistant response against radiation treatment in vivo and in vitro. Taken together, we suggest that DDX6 discovered by using whole genome screening was responsible for radio- and chemoresistance in GBM.
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Affiliation(s)
- Yu Jin Cho
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Wonyoung Kang
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Sung Heon Kim
- Department of Anatomy and Cell Biology, Sungkyunkwan University of Medicine, Suwon, Seoul, Republic of Korea
| | - Jason K Sa
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Nayoung Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Patrick J Paddison
- Department of Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Misuk Kim
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Republic of Korea
| | - Kyeung Min Joo
- Department of Anatomy and Cell Biology, Sungkyunkwan University of Medicine, Suwon, Seoul, Republic of Korea
| | - Young-Il Hwang
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Do-Hyun Nam
- Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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45
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Marchat LA, Arzola-Rodríguez SI, Hernandez-de la Cruz O, Lopez-Rosas I, Lopez-Camarillo C. DEAD/DExH-Box RNA Helicases in Selected Human Parasites. THE KOREAN JOURNAL OF PARASITOLOGY 2015; 53:583-95. [PMID: 26537038 PMCID: PMC4635832 DOI: 10.3347/kjp.2015.53.5.583] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 08/10/2015] [Accepted: 08/10/2015] [Indexed: 11/23/2022]
Abstract
DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.
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Affiliation(s)
- Laurence A Marchat
- Institutional Program of Molecular Biomedicine, Biotechnology Program, National School of Medicine and Homeopathy of the National Polytechnic Institute, Mexico City, CP 07320, Mexico
| | | | | | - Itzel Lopez-Rosas
- Institutional Program of Molecular Biomedicine, Biotechnology Program, National School of Medicine and Homeopathy of the National Polytechnic Institute, Mexico City, CP 07320, Mexico
| | - Cesar Lopez-Camarillo
- Genomics Sciences Program, Autonomous University of Mexico City, Mexico City, CP 03100, Mexico
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46
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Ladomery M, Sommerville J. The Scd6/Lsm14 protein xRAPB has properties different from RAP55 in selecting mRNA for early translation or intracellular distribution in Xenopus oocytes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:1363-73. [PMID: 26455898 DOI: 10.1016/j.bbagrm.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/03/2015] [Accepted: 10/05/2015] [Indexed: 11/17/2022]
Abstract
Oocytes accumulate mRNAs in the form of maternal ribonucleoprotein (RNP) particles, the protein components of which determine the location and stability of individual mRNAs prior to translation. Scd6/Lsm14 proteins, typified by RAP55, function in a wide range of eukaryotes in repressing translation and relocating mRNPs to processing bodies and stress granules. In Xenopus laevis, the RAP55 orthologue xRAPA fulfils these functions. Here we describe the properties of a variant of xRAPA, xRAPB, which is a member of the Lsm14B group. xRAPB differs from xRAPA in various respects: it is expressed at high concentration earlier in oogenesis; it interacts specifically with the DDX6 helicase Xp54; it is detected in polysomes and stalled translation initiation complexes; its over-expression leads to selective binding to translatable mRNA species without evidence of translation repression or mRNA degradation. Since both Xp54 and xRAPA are repressors of translation, activation appears to be effected through targeting of xRAPB/Xp54.
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Affiliation(s)
- Michael Ladomery
- Biomedical Sciences Research Complex, Biomolecular Sciences Building, University of St Andrews, North Haugh, St Andrews KY16 9TS, UK
| | - John Sommerville
- Biomedical Sciences Research Complex, Biomolecular Sciences Building, University of St Andrews, North Haugh, St Andrews KY16 9TS, UK.
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47
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Wang Y, Arribas-Layton M, Chen Y, Lykke-Andersen J, Sen GL. DDX6 Orchestrates Mammalian Progenitor Function through the mRNA Degradation and Translation Pathways. Mol Cell 2015; 60:118-30. [PMID: 26412305 DOI: 10.1016/j.molcel.2015.08.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 06/11/2015] [Accepted: 08/18/2015] [Indexed: 12/26/2022]
Abstract
In adult tissues, stem and progenitor cells must balance proliferation and differentiation to maintain homeostasis. How this is done is unclear. Here, we show that the DEAD box RNA helicase, DDX6 is necessary for maintaining adult progenitor cell function. DDX6 loss results in premature differentiation and decreased proliferation of epidermal progenitor cells. To maintain self-renewal, DDX6 associates with YBX1 to bind the stem loops found in the 3' UTRs of regulators of proliferation/self-renewal (CDK1, EZH2) and recruit them to EIF4E to facilitate their translation. To prevent premature differentiation of progenitor cells, DDX6 regulates the 5' UTR of differentiation inducing transcription factor, KLF4 and degrades its transcripts through association with mRNA degradation proteins. Our results demonstrate that progenitor function is maintained by DDX6 complexes through two distinct pathways that include the degradation of differentiation-inducing transcripts and by promoting the translation of self-renewal and proliferation mRNAs.
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Affiliation(s)
- Ying Wang
- Department of Dermatology, University of California, San Diego, La Jolla, CA 92093-0869, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0869, USA; UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA 92093-0869, USA
| | - Marc Arribas-Layton
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0869, USA
| | - Yifang Chen
- Department of Dermatology, University of California, San Diego, La Jolla, CA 92093-0869, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0869, USA; UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA 92093-0869, USA
| | - Jens Lykke-Andersen
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0869, USA
| | - George L Sen
- Department of Dermatology, University of California, San Diego, La Jolla, CA 92093-0869, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0869, USA; UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA 92093-0869, USA.
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48
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Translation in the mammalian oocyte in space and time. Cell Tissue Res 2015; 363:69-84. [PMID: 26340983 DOI: 10.1007/s00441-015-2269-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 08/03/2015] [Indexed: 02/07/2023]
Abstract
A hallmark of oocyte development in mammals is the dependence on the translation and utilization of stored RNA and proteins rather than the de novo transcription of genes in order to sustain meiotic progression and early embryo development. In the absence of transcription, the completion of meiosis and early embryo development in mammals relies significantly on maternally synthesized RNAs. Post-transcriptional control of gene expression at the translational level has emerged as an important cellular function in normal development. Therefore, the regulation of gene expression in oocytes is controlled almost exclusively at the level of mRNA and protein stabilization and protein synthesis. This current review is focused on the recently emerged findings on RNA distribution related to the temporal and spatial translational control of the meiotic progression of the mammalian oocyte.
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49
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Bish R, Cuevas-Polo N, Cheng Z, Hambardzumyan D, Munschauer M, Landthaler M, Vogel C. Comprehensive Protein Interactome Analysis of a Key RNA Helicase: Detection of Novel Stress Granule Proteins. Biomolecules 2015; 5:1441-66. [PMID: 26184334 PMCID: PMC4598758 DOI: 10.3390/biom5031441] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 06/15/2015] [Indexed: 12/24/2022] Open
Abstract
DDX6 (p54/RCK) is a human RNA helicase with central roles in mRNA decay and translation repression. To help our understanding of how DDX6 performs these multiple functions, we conducted the first unbiased, large-scale study to map the DDX6-centric protein-protein interactome using immunoprecipitation and mass spectrometry. Using DDX6 as bait, we identify a high-confidence and high-quality set of protein interaction partners which are enriched for functions in RNA metabolism and ribosomal proteins. The screen is highly specific, maximizing the number of true positives, as demonstrated by the validation of 81% (47/58) of the RNA-independent interactors through known functions and interactions. Importantly, we minimize the number of indirect interaction partners through use of a nuclease-based digestion to eliminate RNA. We describe eleven new interactors, including proteins involved in splicing which is an as-yet unknown role for DDX6. We validated and characterized in more detail the interaction of DDX6 with Nuclear fragile X mental retardation-interacting protein 2 (NUFIP2) and with two previously uncharacterized proteins, FAM195A and FAM195B (here referred to as granulin-1 and granulin-2, or GRAN1 and GRAN2). We show that NUFIP2, GRAN1, and GRAN2 are not P-body components, but re-localize to stress granules upon exposure to stress, suggesting a function in translation repression in the cellular stress response. Using a complementary analysis that resolved DDX6's multiple complex memberships, we further validated these interaction partners and the presence of splicing factors. As DDX6 also interacts with the E3 SUMO ligase TIF1β, we tested for and observed a significant enrichment of sumoylation amongst DDX6's interaction partners. Our results represent the most comprehensive screen for direct interaction partners of a key regulator of RNA life cycle and localization, highlighting new stress granule components and possible DDX6 functions-many of which are likely conserved across eukaryotes.
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Affiliation(s)
- Rebecca Bish
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA.
| | - Nerea Cuevas-Polo
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA.
| | - Zhe Cheng
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA.
| | - Dolores Hambardzumyan
- The Cleveland Clinic, Department of Neurosciences, Lerner Research Institute, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | - Mathias Munschauer
- RNA Biology and Post-Transcriptional Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin-Buch, Robert-Rössle-Str. 10, Berlin 13092, Germany.
| | - Markus Landthaler
- RNA Biology and Post-Transcriptional Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin-Buch, Robert-Rössle-Str. 10, Berlin 13092, Germany.
| | - Christine Vogel
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA.
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A conserved mechanism of TOR-dependent RCK-mediated mRNA degradation regulates autophagy. Nat Cell Biol 2015; 17:930-942. [PMID: 26098573 PMCID: PMC4528364 DOI: 10.1038/ncb3189] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 05/14/2015] [Indexed: 12/17/2022]
Abstract
Autophagy is an essential eukaryotic pathway requiring tight regulation to maintain homeostasis and preclude disease. Using yeast and mammalian cells, we report a conserved mechanism of autophagy regulation by RNA helicase RCK family members in association with the decapping enzyme Dcp2. Under nutrient-replete conditions, Dcp2 undergoes TOR-dependent phosphorylation and associates with RCK members to form a complex with autophagy-related (ATG) mRNA transcripts, leading to decapping, degradation and autophagy suppression. Simultaneous with the induction of ATG mRNA synthesis, starvation reverses the process, facilitating ATG mRNA accumulation and autophagy induction. This conserved post-transcriptional mechanism modulates fungal virulence and the mammalian inflammasome, the latter providing mechanistic insight into autoimmunity reported in a patient with a PIK3CD/p110δ gain-of-function mutation. We propose a dynamic model wherein RCK family members, in conjunction with Dcp2, function in controlling ATG mRNA stability to govern autophagy, which in turn modulates vital cellular processes affecting inflammation and microbial pathogenesis.
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