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Gahurova L, Tomankova J, Cerna P, Bora P, Kubickova M, Virnicchi G, Kovacovicova K, Potesil D, Hruska P, Zdrahal Z, Anger M, Susor A, Bruce AW. Spatial positioning of preimplantation mouse embryo cells is regulated by mTORC1 and m 7G-cap-dependent translation at the 8- to 16-cell transition. Open Biol 2023; 13:230081. [PMID: 37553074 PMCID: PMC10409569 DOI: 10.1098/rsob.230081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023] Open
Abstract
Preimplantation mouse embryo development involves temporal-spatial specification and segregation of three blastocyst cell lineages: trophectoderm, primitive endoderm and epiblast. Spatial separation of the outer-trophectoderm lineage from the two other inner-cell-mass (ICM) lineages starts with the 8- to 16-cell transition and concludes at the 32-cell stages. Accordingly, the ICM is derived from primary and secondary contributed cells; with debated relative EPI versus PrE potencies. We report generation of primary but not secondary ICM populations is highly dependent on temporal activation of mammalian target of Rapamycin (mTOR) during 8-cell stage M-phase entry, mediated via regulation of the 7-methylguanosine-cap (m7G-cap)-binding initiation complex (EIF4F) and linked to translation of mRNAs containing 5' UTR terminal oligopyrimidine (TOP-) sequence motifs, as knockdown of identified TOP-like motif transcripts impairs generation of primary ICM founders. However, mTOR inhibition-induced ICM cell number deficits in early blastocysts can be compensated by the late blastocyst stage, after inhibitor withdrawal; compensation likely initiated at the 32-cell stage when supernumerary outer cells exhibit molecular characteristics of inner cells. These data identify a novel mechanism specifically governing initial spatial segregation of mouse embryo blastomeres, that is distinct from those directing subsequent inner cell formation, contributing to germane segregation of late blastocyst lineages.
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Affiliation(s)
- Lenka Gahurova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
- Laboratory of Biochemistry and Molecular Biology of Germ Cells, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
| | - Jana Tomankova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Pavlina Cerna
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Pablo Bora
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Michaela Kubickova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Giorgio Virnicchi
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Kristina Kovacovicova
- Laboratory of Cell Division Control, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
| | - David Potesil
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Pavel Hruska
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Zbynek Zdrahal
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Martin Anger
- Laboratory of Cell Division Control, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
| | - Andrej Susor
- Laboratory of Biochemistry and Molecular Biology of Germ Cells, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
| | - Alexander W. Bruce
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
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2
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Tabassum S, Basu M, Ghosh MK. The DEAD-box RNA helicase DDX5 (p68) and β-catenin: The crucial regulators of FOXM1 gene expression in arbitrating colorectal cancer. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - GENE REGULATORY MECHANISMS 2023; 1866:194933. [PMID: 36997114 DOI: 10.1016/j.bbagrm.2023.194933] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/23/2023] [Accepted: 03/22/2023] [Indexed: 03/31/2023]
Abstract
Forkhead box M1 (FOXM1), a vital member of the Forkhead box family of transcription factors, helps in mediating oncogenesis. However, limited knowledge exists regarding the mechanistic insights into the FOXM1 gene regulation. DDX5 (p68), an archetypal member of the DEAD-box family of RNA helicases, shows multifaceted action in cancer progression by arbitrating RNA metabolism and transcriptionally coactivating transcription factors. Here, we report a novel mechanism of alliance between DDX5 (p68) and the Wnt/β-catenin pathway in regulating FOXM1 gene expression and driving colon carcinogenesis. Initial bioinformatic analyses highlighted elevated expression levels of FOXM1 and DDX5 (p68) in colorectal cancer datasets. Immunohistochemical assays confirmed that FOXM1 showed a positive correlation with DDX5 (p68) and β-catenin in both normal and colon carcinoma patient samples. Overexpression of DDX5 (p68) and β-catenin increased the protein and mRNA expression profiles of FOXM1, and the converse correlation occurred during downregulation. Mechanistically, overexpression and knockdown of DDX5 (p68) and β-catenin elevated and diminished FOXM1 promoter activity respectively. Additionally, Chromatin immunoprecipitation assay demonstrated the occupancy of DDX5 (p68) and β-catenin at the TCF4/LEF binding element (TBE) sites on the FOXM1 promoter. Thiostrepton delineated the effect of FOXM1 inhibition on cell proliferation and migration. Colony formation assay, migration assay, and cell cycle data reveal the importance of the DDX5 (p68)/β-catenin/FOXM1 axis in oncogenesis. Collectively, our study mechanistically highlights the regulation of FOXM1 gene expression by DDX5 (p68) and β-catenin in colorectal cancer.
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DEAD/H-box helicases:Anti-viral and pro-viral roles during infections. Virus Res 2021; 309:198658. [PMID: 34929216 DOI: 10.1016/j.virusres.2021.198658] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/26/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023]
Abstract
DEAD/H-box RNA helicases make the prominent family of helicases super family-2 which take part in almost all RNA-related processes, from initiation of transcription to RNA decay pathways. In addition to these RNA-related activities, in recent years a certain number of these helicases are reported to play important roles in anti-viral immunity through various ways. Along with RLHs, endosomal TLRs, and cytosolic DNA receptors, many RNA helicases including DDX3, DHX9, DDX6, DDX41, DHX33, DDX60, DHX36 and DDX1-DDX21-DHX36 complex act as viral nucleic acid sensors or co-sensors. These helicases mostly follow RLHs-MAVS and STING mediated signaling cascades to trigger induction of type-I interferons and pro-inflammatory cytokines. Many of them also function as downstream adaptor molecules (DDX3), segments of stress and processing bodies (DDX3 and DDX6) or negative regulators (DDX19, DDX24, DDX25, DDX39A and DDX46). On the contrary, many studies indicated that several DEAD/H-box helicases such as DDX1, DDX3, DDX6, DDX24, and DHX9 could be exploited by viruses to evade innate immune responses, suggesting that these helicases seem to have a dual function as anti-viral innate immune mediators and viral replication cofactors. In this review, we summarized the current knowledge on several representative DEAD/H-box helicases, with an emphasis on their functions in innate immunity responses, involved in their anti-viral and pro-viral roles.
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Sergeeva O, Abakumova T, Kurochkin I, Ialchina R, Kosyreva A, Prikazchikova T, Varlamova V, Shcherbinina E, Zatsepin T. Level of Murine DDX3 RNA Helicase Determines Phenotype Changes of Hepatocytes In Vitro and In Vivo. Int J Mol Sci 2021; 22:ijms22136958. [PMID: 34203429 PMCID: PMC8269429 DOI: 10.3390/ijms22136958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 11/26/2022] Open
Abstract
DDX3 RNA helicase is intensively studied as a therapeutic target due to participation in the replication of some viruses and involvement in cancer progression. Here we used transcriptome analysis to estimate the primary response of hepatocytes to different levels of RNAi-mediated knockdown of DDX3 RNA helicase both in vitro and in vivo. We found that a strong reduction of DDX3 protein (>85%) led to similar changes in vitro and in vivo—deregulation of the cell cycle and Wnt and cadherin pathways. Also, we observed the appearance of dead hepatocytes in the healthy liver and a decrease of cell viability in vitro after prolonged treatment. However, more modest downregulation of the DDX3 protein (60–65%) showed discordant results in vitro and in vivo—similar changes in vitro as in the case of strong knockdown and a different phenotype in vivo. These results demonstrate that the level of DDX3 protein can dramatically influence the cell phenotype in vivo and the decrease of DDX3, for more than 85% leads to cell death in normal tissues, which should be taken into account during the drug development of DDX3 inhibitors.
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Affiliation(s)
- Olga Sergeeva
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
- Correspondence: ; Tel.: +7-926-388-0865
| | - Tatiana Abakumova
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Ilia Kurochkin
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Renata Ialchina
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Anna Kosyreva
- Research Institute of Human Morphology, 117418 Moscow, Russia;
| | - Tatiana Prikazchikova
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Varvara Varlamova
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Evgeniya Shcherbinina
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
| | - Timofei Zatsepin
- Skolkovo Institute of Science and Technology, Skolkovo, 121205 Moscow, Russia; (T.A.); (I.K.); (R.I.); (T.P.); (V.V.); (E.S.); (T.Z.)
- Department of Chemistry, Lomonosov Moscow State University, 119992 Moscow, Russia
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Chen Z, Li Z, Hu X, Xie F, Kuang S, Zhan B, Gao W, Chen X, Gao S, Li Y, Wang Y, Qian F, Ding C, Gan J, Ji C, Xu X, Zhou Z, Huang J, He HH, Li J. Structural Basis of Human Helicase DDX21 in RNA Binding, Unwinding, and Antiviral Signal Activation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000532. [PMID: 32714761 PMCID: PMC7375243 DOI: 10.1002/advs.202000532] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/19/2020] [Indexed: 05/20/2023]
Abstract
RNA helicase DDX21 plays vital roles in ribosomal RNA biogenesis, transcription, and the regulation of host innate immunity during virus infection. How DDX21 recognizes and unwinds RNA and how DDX21 interacts with virus remain poorly understood. Here, crystal structures of human DDX21 determined in three distinct states are reported, including the apo-state, the AMPPNP plus single-stranded RNA (ssRNA) bound pre-hydrolysis state, and the ADP-bound post-hydrolysis state, revealing an open to closed conformational change upon RNA binding and unwinding. The core of the RNA unwinding machinery of DDX21 includes one wedge helix, one sensor motif V and the DEVD box, which links the binding pockets of ATP and ssRNA. The mutant D339H/E340G dramatically increases RNA binding activity. Moreover, Hill coefficient analysis reveals that DDX21 unwinds double-stranded RNA (dsRNA) in a cooperative manner. Besides, the nonstructural (NS1) protein of influenza A inhibits the ATPase and unwinding activity of DDX21 via small RNAs, which cooperatively assemble with DDX21 and NS1. The structures illustrate the dynamic process of ATP hydrolysis and RNA unwinding for RNA helicases, and the RNA modulated interaction between NS1 and DDX21 generates a fresh perspective toward the virus-host interface. It would benefit in developing therapeutics to combat the influenza virus infection.
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Affiliation(s)
- Zijun Chen
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Zhengyang Li
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Xiaojian Hu
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Feiyan Xie
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Siyun Kuang
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Bowen Zhan
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Wenqing Gao
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
| | - Xiangjun Chen
- Department of NeurologyHuashan HospitalFudan UniversityShanghai200040China
| | - Siqi Gao
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Yang Li
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Yongming Wang
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Feng Qian
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Chen Ding
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Jianhua Gan
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Chaoneng Ji
- State Key Laboratory of Genetic EngineeringSchool of Life SciencesFudan UniversityShanghai200438China
| | - Xue‐Wei Xu
- Key Laboratory of Marine Ecosystem DynamicsMinistry of Natural Resources & Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China
| | - Zheng Zhou
- China Novartis Institutes for Biomedical Research Co. LtdShanghai201203China
| | - Jinqing Huang
- Department of ChemistryThe Hong Kong University of Science and TechnologyHong KongChina
| | - Housheng Hansen He
- Department of Medical BiophysicsUniversity of Toronto, and Princess Margaret Cancer CenterUniversity Health NetworkTorontoM5G 1L7, OntarioCanada
| | - Jixi Li
- State Key Laboratory of Genetic EngineeringDepartment of NeurologySchool of Life Sciences and Huashan HospitalCollaborative Innovation Center of Genetics and DevelopmentEngineering Research Center of Gene Technology of MOEShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghai200438China
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Sithole N, Williams CA, Abbink TEM, Lever AML. DDX5 potentiates HIV-1 transcription as a co-factor of Tat. Retrovirology 2020; 17:6. [PMID: 32228614 PMCID: PMC7106839 DOI: 10.1186/s12977-020-00514-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/16/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND HIV-1 does not encode a helicase and hijacks those of the cell for efficient replication. We and others previously showed that the DEAD box helicase, DDX5, is an essential HIV dependency factor. DDX5 was recently shown to be associated with the 7SK snRNP. Cellular positive transcription elongation factor b (P-TEFb) is bound in an inactive form with HEXIM1/2 on 7SK snRNP. The Tat/P-TEFb complex is essential for efficient processivity of Pol II in HIV-1 transcription elongation and Tat competes with HEXIM1/2 for P-TEFb. We investigated the precise role of DDX5 in HIV replication using siRNA mediated knockdown and rescue with DDX5 mutants which prevent protein-protein interactions and RNA and ATP binding. RESULTS We demonstrate a critical role for DDX5 in the Tat/HEXIM1 interaction. DDX5 acts to potentiate Tat activity and can bind both Tat and HEXIM1 suggesting it may facilitate the dissociation of HEXIM1/2 from the 7SK-snRNP complex, enhancing Tat/P-TEFb availability. We show knockdown of DDX5 in a T cell line significantly reduces HIV-1 infectivity and viral protein production. This activity is unique to DDX5 and cannot be substituted by its close paralog DDX17. Overexpression of DDX5 stimulates the Tat/LTR promoter but suppresses other cellular and viral promoters. Individual mutations of conserved ATP binding, RNA binding, helicase related or protein binding motifs within DDX5 show that the N terminal RNA binding motifs, the Walker B and the glycine doublet motifs are essential for this function. The Walker A and RNA binding motifs situated on the transactivation domain are however dispensable. CONCLUSION DDX5 is an essential cellular factor for efficient HIV transcription elongation. It interacts with Tat and may potentiate the availability of P-TEFb through sequestering HEXIM1.
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Affiliation(s)
- Nyaradzai Sithole
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Claire A Williams
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Department of Microbiology, Specialist Virology Centre, Norfolk and Norwich University Hospitals, Norwich, UK
| | - Truus E M Abbink
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Department of Paediatrics, Child Neurology, Centre for Childhood White Matter Disorders, VU University Medical Centre, Amsterdam, The Netherlands
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
- Department of Medicine, National University of Singapore, Singapore, 119228, Singapore.
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Perčulija V, Ouyang S. Diverse Roles of DEAD/DEAH-Box Helicases in Innate Immunity and Diseases. HELICASES FROM ALL DOMAINS OF LIFE 2019. [PMCID: PMC7158350 DOI: 10.1016/b978-0-12-814685-9.00009-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
DEAD/DEAH-box helicases are enzymes that belong to the DEAD/H-box family of SF2 helicase superfamily. These enzymes are essential in RNA metabolism, where they are involved in a number of processes that require manipulation of RNA structure. Recent studies have found that some DEAD/DEAH-box helicases play important roles in innate immunity, where they act as sensors of cytosolic DNA/RNA, as adaptor proteins, or as regulators of signaling and gene expression. In spite of their function in immunity, DEAD/DEAH-box helicases can also be hijacked and exploited by viruses to circumvent detection and aid in viral replication. These findings not only imply that DEAD/DEAH-box helicases have a broader function than previously thought, but also give us a much better understanding of immune mechanisms and diseases that arise due to the dysregulation or evasion thereof. In this chapter, we demonstrate the known scope of activities of human DEAD/DEAH-box helicases in innate immunity and interaction with viruses or other pathogens. Additionally, we give an outline of diseases in which they are, or may be, involved in the context of immunity.
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8
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Sithole N, Williams CA, Vaughan AM, Kenyon JC, Lever AML. DDX17 Specifically, and Independently of DDX5, Controls Use of the HIV A4/5 Splice Acceptor Cluster and Is Essential for Efficient Replication of HIV. J Mol Biol 2018; 430:3111-3128. [PMID: 30131116 PMCID: PMC6119765 DOI: 10.1016/j.jmb.2018.06.052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 12/11/2022]
Abstract
HIV splicing involves five splice donor and eight splice acceptor sequences which, together with cryptic splice sites, generate over 100 mRNA species. Ninety percent of both partially spliced and fully spliced transcripts utilize the intrinsically weak A4/A5 3' splice site cluster. We show that DDX17, but not its close paralog DDX5, specifically controls the usage of this splice acceptor group. In its absence, production of the viral envelope protein and other regulatory and accessory proteins is grossly reduced, while Vif, which uses the A1 splice acceptor, is unaffected. This is associated with a profound decrease in viral export from the cell. Loss of Vpu expression causing upregulation of cellular Tetherin compounds the phenotype. DDX17 utilizes distinct RNA binding motifs for its role in efficient HIV replication, and we identify RNA binding motifs essential for its role, while the Walker A, Walker B (DEAD), Q motif and the glycine doublet motif are all dispensable. We show that DDX17 interacts with SRSF1/SF2 and the heterodimeric auxiliary factor U2AF65/35, which are essential splicing factors in the generation of Rev and Env/Vpu transcripts.
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Affiliation(s)
- Nyaradzai Sithole
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Claire A Williams
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Aisling M Vaughan
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Julia C Kenyon
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK; Department of Microbiology and Immunology, National University of Singapore, Singapore 117545
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Cambridge, CB2 0QQ, UK; Department of Medicine, National University of Singapore, Singapore 119228.
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Zhang L, Yang Y, Li B, Scott IC, Lou X. The DEAD box RNA helicase Ddx39ab is essential for myocyte and lens development in zebrafish. Development 2018; 145:dev.161018. [DOI: 10.1242/dev.161018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/13/2018] [Indexed: 12/20/2022]
Abstract
RNA helicases from the DEAD-box family are found in almost all organisms and have important roles in RNA metabolism including RNA synthesis, processing and degradation. The function and mechanism of action of most of these helicases in animal development and human disease are largely unexplored. In a zebrafish mutagenesis screen to identify genes essential for heart development we identified a mutant which disrupts the gene encoding the RNA helicase DEAD-box 39ab (ddx39ab). Homozygous ddx39ab mutant embryos exhibit profound cardiac and trunk muscle dystrophy, along with lens abnormalities, caused by abrupt terminal differentiation of cardiomyocyte, myoblast and lens fiber cells. Further investigation indicated that loss of ddx39ab hindered mRNA splicing of members of the kmt2 gene family, leading to mis-regulation of structural gene expression in cardiomyocyte, myoblast and lens fiber cells. Taken together, these results show that Ddx39ab plays an essential role in establishment of proper epigenetic status during differentiation of multiple cell lineages.
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Affiliation(s)
- Linlin Zhang
- Model Animal Research Center, Nanjing University, China
| | - Yuxi Yang
- Model Animal Research Center, Nanjing University, China
| | - Beibei Li
- Model Animal Research Center, Nanjing University, China
| | - Ian C. Scott
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Canada
- Department of Molecular Genetics, University of Toronto, Canada
| | - Xin Lou
- Model Animal Research Center, Nanjing University, China
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10
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Peckham-Gregory EC, Thapa DR, Martinson J, Duggal P, Penugonda S, Bream JH, Chang PY, Dandekar S, Chang SC, Detels R, Martínez-Maza O, Zhang ZF, Hussain SK. MicroRNA-related polymorphisms and non-Hodgkin lymphoma susceptibility in the Multicenter AIDS Cohort Study. Cancer Epidemiol 2016; 45:47-57. [PMID: 27701053 DOI: 10.1016/j.canep.2016.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/12/2016] [Accepted: 09/19/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND MicroRNAs, small non-coding RNAs involved in gene regulation, are implicated in lymphomagenesis. We evaluated whether genetic variations in microRNA coding regions, binding sites, or biogenesis genes (collectively referred to as miRNA-SNPs) were associated with risk of AIDS-associated non-Hodgkin lymphoma (AIDS-NHL), and serum levels of four lymphoma-related microRNAs. METHODS Twenty-five miRNA-SNPs were genotyped in 180 AIDS-NHL cases and 529 HIV-infected matched controls from the Multicenter AIDS Cohort Study (MACS), and real-time polymerase chain reaction was used to quantify serum microRNA levels. Adjusted odds ratios (ORs) estimated using conditional logistic regression evaluated associations between miRNA-SNPs and AIDS-NHL risk. A semi-Bayes shrinkage approach was employed to reduce likelihood of false-positive associations. Adjusted mean ratios (MR) calculated using linear regression assessed associations between miRNA-SNPs and serum microRNA levels. RESULTS DDX20 rs197412, a non-synonymous miRNA biogenesis gene SNP, was associated with AIDS-NHL risk (OR=1.34 per minor allele; 95% CI: 1.02-1.75), and higher miRNA-222 serum levels nearing statistical significance (MR=1.21 per minor allele; 95% CI: 0.98-1.49). MiRNA-196a2 rs11614913 was associated with decreased central nervous system (CNS) AIDS-NHL (CT vs. CC OR=0.52; 95% CI: 0.27-0.99). The minor allele of HIF1A rs2057482, which creates a miRNA-196a2 binding site, was associated with systemic AIDS-NHL risk (OR=1.73 per minor allele; 95% CI: 1.12-2.67), and decreased CNS AIDS-NHL risk (OR=0.49 per minor allele; 95% CI: 0.25-0.94). CONCLUSIONS This study suggests that a few miRNA-SNPs are associated with AIDS-NHL risk and may modulate miRNA expression. These results support a role for miRNA in AIDS-NHL and may highlight pathways to be targeted for risk stratification or therapeutics.
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Affiliation(s)
- Erin C Peckham-Gregory
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA.
| | - Dharma R Thapa
- Departments of Obstetrics and Gynecology, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, UCLA, Box 951740, 153 BSRB, Los Angeles, CA 90095-1740, USA
| | - Jeremy Martinson
- Department of Infectious Disease and Microbiology, Graduate School of Public Health, University of Pittsburgh, 403 Parran Hall, 130 DeSoto Street, Pittsburgh, PA 15261, USA
| | - Priya Duggal
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Room E6539, Baltimore, MD 21205, USA
| | - Sudhir Penugonda
- Division of Infectious Diseases, Feinberg School of Medicine, Northwestern University, 645 North Michigan Avenue, Suite 900, Chicago, IL 60611, USA
| | - Jay H Bream
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Room E5624, Baltimore, MD 21205, USA
| | - Po-Yin Chang
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA
| | - Sugandha Dandekar
- The UCLA Genotyping and Sequencing Core, Department of Human Genetics, David Geffen School of Medicine, UCLA, CHS 36-125, 650 Charles E Young Drive South, Los Angeles, CA 90095, USA
| | - Shen-Chih Chang
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA
| | - Roger Detels
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA
| | - Otoniel Martínez-Maza
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA; Departments of Obstetrics and Gynecology, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, UCLA, Box 951740, 153 BSRB, Los Angeles, CA 90095-1740, USA; Jonsson Comprehensive Cancer Center, UCLA, Box 951740, 153 BSRB, Los Angeles, CA 90095-1740, USA; UCLA AIDS Institute, UCLA, Box 951740, 153 BSRB, Los Angeles, CA 90095-1740, USA
| | - Zuo-Feng Zhang
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA
| | - Shehnaz K Hussain
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles (UCLA), Box 951772, 71-267 CHS, Los Angeles, CA 90095-1772, USA; Department of Medicine and Samuel Oschin Comprehensive Cancer Center, Cedars-Sinai Medical Center, 8700 Beverly Blvd, West Hollywood, CA 90048, USA
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p53-directed translational control can shape and expand the universe of p53 target genes. Cell Death Differ 2014; 21:1522-34. [PMID: 24926617 DOI: 10.1038/cdd.2014.79] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 04/23/2014] [Accepted: 04/30/2014] [Indexed: 01/20/2023] Open
Abstract
The increasing number of genome-wide transcriptome analyses focusing on p53-induced cellular responses in many cellular contexts keeps adding to the already numerous p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses, we performed a translatome analysis through polysomal profiling on MCF7 cells upon 16 hours of doxorubicin or nutlin-3a treatment. The comparison between the transcriptome and the translatome revealed a considerable level of uncoupling, characterized by genes whose transcription variations did not correlate with translation variations. Interestingly, uncoupled genes were associated with apoptosis, DNA and RNA metabolism and cell cycle functions, suggesting that post-transcriptional control can modulate classical p53-regulated responses. Furthermore, even for well-established p53 targets that were differentially expressed both at the transcriptional and translational levels, quantitative differences between the transcriptome, subpolysomal and polysomal RNAs were evident. As we searched mechanisms underlying gene expression uncoupling, we identified the p53-dependent modulation of six RNA-binding proteins, where hnRNPD (AUF1) and CPEB4 are direct p53 transcriptional targets, whereas SRSF1, DDX17, YBX1 and TARDBP are indirect targets (genes modulated preferentially in the subpolysomal or polysomal mRNA level) modulated at the translational level in a p53-dependent manner. In particular, YBX1 translation appeared to be reduced by p53 via two different mechanisms, one related to mTOR inhibition and the other to miR-34a expression. Overall, we established p53 as a master regulator of translational control and identified new p53-regulated genes affecting translation that can contribute to p53-dependent cellular responses.
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Post-transcriptional regulation of connexin43 in H-Ras-transformed cells. PLoS One 2013; 8:e58500. [PMID: 23505521 PMCID: PMC3594296 DOI: 10.1371/journal.pone.0058500] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 02/05/2013] [Indexed: 01/05/2023] Open
Abstract
Connexin43 (Cx43) expression is lost in cancer cells and many studies have reported that Cx43 is a tumor suppressor gene. Paradoxically, in a cellular NIH3T3 model, we have previously shown that Ha-Ras-mediated oncogenic transformation results in increased Cx43 expression. Although the examination of transcriptional regulation revealed essential regulatory elements, it could not solve this paradox. Here we studied post-transcriptional regulation of Cx43 expression in cancer using the same model in search of novel gene regulatory elements. Upon Ras transformation, both Cx43 mRNA stability and translation efficiency were increased. We investigated the role of Cx43 mRNA 3′ and 5′Untranslated regions (UTRs) and found an opposing effect; a 5′UTR-driven positive regulation is observed in Ras-transformed cells (NIH-3T3Ras), while the 3′UTR is active only in normal NIH-3T3Neo cells and completely silenced in NIH-3T3Ras cells. Most importantly, we identified a previously unknown regulatory element within the 3′UTR, named S1516, which accounts for this 3′UTR-mediated regulation. We also examined the effect of other oncogenes and found that Ras- and Src-transformed cells show a different Cx43 UTRs post-transcriptional regulation than ErbB2-transformed cells, suggesting distinct regulatory pathways. Next, we detected different patterns of S1516 RNA-protein complexes in NIH-3T3Neo compared to NIH-3T3Ras cells. A proteomic approach identified most of the S1516-binding proteins as factors involved in post-transcriptional regulation. Building on our new findings, we propose a model to explain the discrepancy between the Cx43 expression in Ras-transformed NIH3T3 cells and the data in clinical specimens.
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