1
|
Nagasawa CK, Bailey AO, Russell WK, Garcia-Blanco MA. Inefficient recruitment of DDX39B impedes pre-spliceosome assembly on FOXP3 introns. RNA (NEW YORK, N.Y.) 2024; 30:824-838. [PMID: 38575347 PMCID: PMC11182011 DOI: 10.1261/rna.079933.123] [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: 12/22/2023] [Accepted: 03/19/2024] [Indexed: 04/06/2024]
Abstract
Forkhead box P3 (FOXP3) is the master fate-determining transcription factor in regulatory T (Treg) cells and is essential for their development, function, and homeostasis. Mutations in FOXP3 cause immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, and aberrant expression of FOXP3 has been implicated in other diseases such as multiple sclerosis and cancer. We previously demonstrated that pre-mRNA splicing of FOXP3 RNAs is highly sensitive to levels of DExD-box polypeptide 39B (DDX39B), and here we investigate the mechanism of this sensitivity. FOXP3 introns have cytidine (C)-rich/uridine (U)-poor polypyrimidine (py) tracts that are responsible for their inefficient splicing and confer sensitivity to DDX39B. We show that there is a deficiency in the assembly of commitment complexes (CCs) on FOXP3 introns, which is consistent with the lower affinity of U2AF2 for C-rich/U-poor py tracts. Our data indicate an even stronger effect on the conversion of CCs to pre-spliceosomes. We propose that this is due to an altered conformation that U2AF2 adopts when it binds to C-rich/U-poor py tracts and that this conformation has a lower affinity for DDX39B. As a consequence, CCs assembled on FOXP3 introns are defective in recruiting DDX39B, and this leads to the inefficient assembly of pre-spliceosome complexes.
Collapse
Affiliation(s)
- Chloe K Nagasawa
- Human Pathophysiology and Translational Medicine Program, Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas 77550, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77550, USA
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Aaron O Bailey
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77550, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77550, USA
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77550, USA
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia 22908, USA
| |
Collapse
|
2
|
Yellamaty R, Sharma S. Critical Cellular Functions and Mechanisms of Action of the RNA Helicase UAP56. J Mol Biol 2024; 436:168604. [PMID: 38729260 PMCID: PMC11168752 DOI: 10.1016/j.jmb.2024.168604] [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: 03/06/2024] [Revised: 04/24/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024]
Abstract
Posttranscriptional maturation and export from the nucleus to the cytoplasm are essential steps in the normal processing of many cellular RNAs. The RNA helicase UAP56 (U2AF associated protein 56; also known as DDX39B) has emerged as a critical player in facilitating and co-transcriptionally linking these steps. Originally identified as a helicase involved in pre-mRNA splicing, UAP56 has been shown to facilitate formation of the A complex during spliceosome assembly. Additionally, it has been found to be critical for interactions between components of the exon junction and transcription and export complexes to promote the loading of export receptors. Although it appears to be structurally similar to other helicase superfamily 2 members, UAP56's ability to interact with multiple different protein partners allows it to perform its various cellular functions. Herein, we describe the structure-activity relationship studies that identified protein interactions of UAP56 and its human paralog URH49 (UAP56-related helicase 49; also known as DDX39A) and are beginning to reveal molecular mechanisms by which interacting proteins and substrate RNAs may regulate these helicases. We also provide an overview of reports that have demonstrated less well-characterized roles for UAP56, including R-loop resolution and telomere maintenance. Finally, we discuss studies that indicate a potential pathogenic effect of UAP56 in the development of autoimmune diseases and cancer, and identify the association of somatic and genetic mutations in UAP56 with neurodevelopmental disorders.
Collapse
Affiliation(s)
- Ryan Yellamaty
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ 85004, USA
| | - Shalini Sharma
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ 85004, USA.
| |
Collapse
|
3
|
Banerjee S, Nagasawa CK, Widen SG, Garcia-Blanco MA. Parsing the roles of DExD-box proteins DDX39A and DDX39B in alternative RNA splicing. Nucleic Acids Res 2024:gkae431. [PMID: 38801080 DOI: 10.1093/nar/gkae431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 05/01/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024] Open
Abstract
DExD-box RNA proteins DDX39A and DDX39B are highly homologous paralogs that are conserved in vertebrates. They are required for energy-driven reactions involved in RNA processing. Although we have some understanding of how their functions overlap in RNA nuclear export, our knowledge of whether or not these proteins have specific or redundant functions in RNA splicing is limited. Our previous work has shown that DDX39B is responsible for regulating the splicing of important immune transcripts IL7R and FOXP3. In this study, we aimed to investigate whether DDX39A, a highly homologous paralog of DDX39B, plays a similar role in regulating alternative RNA splicing. We find that DDX39A and DDX39B have significant redundancy in their gene targets, but there are targets that uniquely require one or the other paralog. For instance, DDX39A is incapable of complementing defective splicing of IL7R exon 6 when DDX39B is depleted. This exon and other cassette exons that specifically depend on DDX39B have U-poor/C-rich polypyrimidine tracts in the upstream intron and this variant polypyrimidine tract is required for DDX39B dependency. This study provides evidence that despite a high degree of functional redundancy, DDX39A and DDX39B are selectively required for the splicing of specific pre-mRNAs.
Collapse
Affiliation(s)
- Shefali Banerjee
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Chloe K Nagasawa
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
- Human Pathophysiology and Translational Medicine Program, Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555-5302, USA
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Mariano A Garcia-Blanco
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| |
Collapse
|
4
|
Marijan D, Momchilova EA, Burns D, Chandhok S, Zapf R, Wille H, Potoyan DA, Audas TE. Protein thermal sensing regulates physiological amyloid aggregation. Nat Commun 2024; 15:1222. [PMID: 38336721 PMCID: PMC10858206 DOI: 10.1038/s41467-024-45536-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
To survive, cells must respond to changing environmental conditions. One way that eukaryotic cells react to harsh stimuli is by forming physiological, RNA-seeded subnuclear condensates, termed amyloid bodies (A-bodies). The molecular constituents of A-bodies induced by different stressors vary significantly, suggesting this pathway can tailor the cellular response by selectively aggregating a subset of proteins under a given condition. Here, we identify critical structural elements that regulate heat shock-specific amyloid aggregation. Our data demonstrates that manipulating structural pockets in constituent proteins can either induce or restrict their A-body targeting at elevated temperatures. We propose a model where selective aggregation within A-bodies is mediated by the thermal stability of a protein, with temperature-sensitive structural regions acting as an intrinsic form of post-translational regulation. This system would provide cells with a rapid and stress-specific response mechanism, to tightly control physiological amyloid aggregation or other cellular stress response pathways.
Collapse
Affiliation(s)
- Dane Marijan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Evgenia A Momchilova
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Daniel Burns
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Sahil Chandhok
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Richard Zapf
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Holger Wille
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Davit A Potoyan
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
| | - Timothy E Audas
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
| |
Collapse
|
5
|
Fujita KI, Ito M, Irie M, Harada K, Fujiwara N, Ikeda Y, Yoshioka H, Yamazaki T, Kojima M, Mikami B, Mayeda A, Masuda S. Structural differences between the closely related RNA helicases, UAP56 and URH49, fashion distinct functional apo-complexes. Nat Commun 2024; 15:455. [PMID: 38225262 PMCID: PMC10789772 DOI: 10.1038/s41467-023-44217-8] [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: 04/23/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
mRNA export is an essential pathway for the regulation of gene expression. In humans, closely related RNA helicases, UAP56 and URH49, shape selective mRNA export pathways through the formation of distinct complexes, known as apo-TREX and apo-AREX complexes, and their subsequent remodeling into similar ATP-bound complexes. Therefore, defining the unidentified components of the apo-AREX complex and elucidating the molecular mechanisms underlying the formation of distinct apo-complexes is key to understanding their functional divergence. In this study, we identify additional apo-AREX components physically and functionally associated with URH49. Furthermore, by comparing the structures of UAP56 and URH49 and performing an integrated analysis of their chimeric mutants, we exhibit unique structural features that would contribute to the formation of their respective complexes. This study provides insights into the specific structural and functional diversification of these two helicases that diverged from the common ancestral gene Sub2.
Collapse
Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan.
- Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
| | - Misa Ito
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Midori Irie
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Kotaro Harada
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Naoko Fujiwara
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Yuya Ikeda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Hanae Yoshioka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Masaki Kojima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Bunzo Mikami
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, 611-0011, Japan
- Institute of Advanced Energy, Kyoto University, Kyoto, 611-0011, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan.
- Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan.
- Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
| |
Collapse
|
6
|
Bohnsack KE, Yi S, Venus S, Jankowsky E, Bohnsack MT. Cellular functions of eukaryotic RNA helicases and their links to human diseases. Nat Rev Mol Cell Biol 2023; 24:749-769. [PMID: 37474727 DOI: 10.1038/s41580-023-00628-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/22/2023]
Abstract
RNA helicases are highly conserved proteins that use nucleoside triphosphates to bind or remodel RNA, RNA-protein complexes or both. RNA helicases are classified into the DEAD-box, DEAH/RHA, Ski2-like, Upf1-like and RIG-I families, and are the largest class of enzymes active in eukaryotic RNA metabolism - virtually all aspects of gene expression and its regulation involve RNA helicases. Mutation and dysregulation of these enzymes have been linked to a multitude of diseases, including cancer and neurological disorders. In this Review, we discuss the regulation and functional mechanisms of RNA helicases and their roles in eukaryotic RNA metabolism, including in transcription regulation, pre-mRNA splicing, ribosome assembly, translation and RNA decay. We highlight intriguing models that link helicase structure, mechanisms of function (such as local strand unwinding, translocation, winching, RNA clamping and displacing RNA-binding proteins) and biological roles, including emerging connections between RNA helicases and cellular condensates formed through liquid-liquid phase separation. We also discuss associations of RNA helicases with human diseases and recent efforts towards the design of small-molecule inhibitors of these pivotal regulators of eukaryotic gene expression.
Collapse
Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
| | - Soon Yi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Moderna, Cambridge, MA, USA.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| |
Collapse
|
7
|
Hirano M, Galarza-Muñoz G, Nagasawa C, Schott G, Wang L, Antonia AL, Jain V, Yu X, Widen SG, Briggs FBS, Gregory SG, Ko DC, Fagg WS, Bradrick S, Garcia-Blanco MA. The RNA helicase DDX39B activates FOXP3 RNA splicing to control T regulatory cell fate. eLife 2023; 12:e76927. [PMID: 37261960 PMCID: PMC10234631 DOI: 10.7554/elife.76927] [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: 01/10/2022] [Accepted: 05/09/2023] [Indexed: 06/03/2023] Open
Abstract
Genes associated with increased susceptibility to multiple sclerosis (MS) have been identified, but their functions are incompletely understood. One of these genes codes for the RNA helicase DExD/H-Box Polypeptide 39B (DDX39B), which shows genetic and functional epistasis with interleukin-7 receptor-α gene (IL7R) in MS-risk. Based on evolutionary and functional arguments, we postulated that DDX39B enhances immune tolerance thereby decreasing MS risk. Consistent with such a role we show that DDX39B controls the expression of many MS susceptibility genes and important immune-related genes. Among these we identified Forkhead Box P3 (FOXP3), which codes for the master transcriptional factor in CD4+/CD25+ T regulatory cells. DDX39B knockdown led to loss of immune-regulatory and gain of immune-effector expression signatures. Splicing of FOXP3 introns, which belong to a previously unrecognized type of introns with C-rich polypyrimidine tracts, was exquisitely sensitive to DDX39B levels. Given the importance of FOXP3 in autoimmunity, this work cements DDX39B as an important guardian of immune tolerance.
Collapse
Affiliation(s)
- Minato Hirano
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- National Research Center for the Control and Prevention of Infectious Disease, Nagasaki UniversityNagasakiJapan
| | - Gaddiel Galarza-Muñoz
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- Autoimmunity Biological SolutionsGalvestonUnited States
| | - Chloe Nagasawa
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- Human Pathophysiology and Translational Medicine Program, Institute for Translational Sciences, University of Texas Medical BranchGalvestonUnited States
| | - Geraldine Schott
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, Duke UniversityDurhamUnited States
| | - Alejandro L Antonia
- Department of Molecular Genetics and Microbiology, Duke UniversityDurhamUnited States
| | - Vaibhav Jain
- Duke Molecular Physiology Institute, Duke UniversityDurhamUnited States
| | - Xiaoying Yu
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- Department of Preventive Medicine and Population Health, University of Texas Medical BranchGalvestonUnited States
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
| | - Farren BS Briggs
- Department of Population and Quantitative Health Sciences, School of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Simon G Gregory
- Department of Molecular Genetics and Microbiology, Duke UniversityDurhamUnited States
- Duke Molecular Physiology Institute, Duke UniversityDurhamUnited States
- Department of Neurology, Duke University School of MedicineDurhamUnited States
| | - Dennis C Ko
- Department of Molecular Genetics and Microbiology, Duke UniversityDurhamUnited States
- Division of Infectious Diseases, Department of Medicine, Duke UniversityDurhamUnited States
| | - William S Fagg
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- Transplant Division, Department of Surgery, University of Texas Medical BranchGalvestonUnited States
| | - Shelton Bradrick
- Institute of Human Infections and Immunity, University of Texas Medical BranchGalvestonUnited States
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical BranchGalvestonUnited States
- Department of Internal Medicine, University of Texas Medical BranchGalvestonUnited States
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| |
Collapse
|
8
|
Chellini L, Pieraccioli M, Sette C, Paronetto MP. The DNA/RNA helicase DHX9 contributes to the transcriptional program of the androgen receptor in prostate cancer. J Exp Clin Cancer Res 2022; 41:178. [PMID: 35590370 PMCID: PMC9118622 DOI: 10.1186/s13046-022-02384-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/05/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Prostate cancer (PC) is the most commonly diagnosed male malignancy and an important cause of mortality. Androgen deprivation therapy is the first line treatment but, unfortunately, a large part of patients evolves to a castration-resistant stage, for which no effective cure is currently available. The DNA/RNA helicase DHX9 is emerging as an important regulator of cellular processes that are often deregulated in cancer.
Methods
To investigate whether DHX9 modulates PC cell transcriptome we performed RNA-sequencing analyses upon DHX9 silencing in the androgen-responsive cell line LNCaP. Bioinformatics and functional analyses were carried out to elucidate the mechanism of gene expression regulation by DHX9. Data from The Cancer Genome Atlas were mined to evaluate the potential role of DHX9 in PC.
Results
We found that up-regulation of DHX9 correlates with advanced stage and is associated with poor prognosis of PC patients. High-throughput RNA-sequencing analysis revealed that depletion of DHX9 in androgen-sensitive LNCaP cells affects expression of hundreds of genes, which significantly overlap with known targets of the Androgen Receptor (AR). Notably, AR binds to the DHX9 promoter and induces its expression, while Enzalutamide-mediated inhibition of AR activity represses DHX9 expression. Moreover, DHX9 interacts with AR in LNCaP cells and its depletion significantly reduced the recruitment of AR to the promoter region of target genes and the ability of AR to promote their expression in response to 5α-dihydrotestosterone. Consistently, silencing of DXH9 negatively affected androgen-induced PC cell proliferation and migration.
Conclusions
Collectively, our data uncover a new role of DHX9 in the control of the AR transcriptional program and establish the existence of an oncogenic DHX9/AR axis, which may represent a new druggable target to counteract PC progression.
Collapse
|
9
|
Li Y, Du Y, Huai J, Jing Y, Lin R. The RNA helicase UAP56 and the E3 ubiquitin ligase COP1 coordinately regulate alternative splicing to repress photomorphogenesis in Arabidopsis. THE PLANT CELL 2022; 34:4191-4212. [PMID: 35920787 PMCID: PMC9614450 DOI: 10.1093/plcell/koac235] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Light is a key environmental signal that regulates plant growth and development. While posttranscriptional regulatory mechanisms of gene expression include alternative splicing (AS) of pre-messenger RNA (mRNA) in both plants and animals, how light signaling affects AS in plants is largely unknown. Here, we identify DExD/H RNA helicase U2AF65-associated protein (UAP56) as a negative regulator of photomorphogenesis in Arabidopsis thaliana. UAP56 is encoded by the homologs UAP56a and UAP56b. Knockdown of UAP56 led to enhanced photomorphogenic responses and diverse developmental defects during vegetative and reproductive growth. UAP56 physically interacts with the central light signaling repressor constitutive photomorphogenic 1 (COP1) and U2AF65. Global transcriptome analysis revealed that UAP56 and COP1 co-regulate the transcription of a subset of genes. Furthermore, deep RNA-sequencing analysis showed that UAP56 and COP1 control pre-mRNA AS in both overlapping and distinct manners. Ribonucleic acid immunoprecipitation assays showed that UAP56 and COP1 bind to common small nuclear RNAs and mRNAs of downstream targets. Our study reveals that both UAP56 and COP1 function as splicing factors that coordinately regulate AS during light-regulated plant growth and development.
Collapse
Affiliation(s)
- Yang Li
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanxin Du
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junling Huai
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yanjun Jing
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | | |
Collapse
|
10
|
TREX (transcription/export)-NP complex exerts a dual effect on regulating polymerase activity and replication of influenza A virus. PLoS Pathog 2022; 18:e1010835. [PMID: 36084138 PMCID: PMC9491529 DOI: 10.1371/journal.ppat.1010835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 09/21/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022] Open
Abstract
Influenza A viruses effectively hijack the intracellular "resources" to complete transcription and replication, which involve extensive interactions between the viral and host proteins. Herein, we screened the host factors, which belong to DExD/H-box protein family members, RNA-binding proteins or mitochondrial anchoring proteins, to investigate their effects on polymerase activity. We observed DDX39B and DDX39A, DEAD-box RNA-Helicases, exert a dual effect on regulating polymerase activity and replication of influenza A viruses. We further revealed that DDX39B and DDX39A interact with viral NP and NS1 proteins. Interestingly, the viral NP proteins could reverse the inhibitory effect of excess DDX39B or DDX39A on polymerase activity. Mechanistically, the TREX complex subunits, THOC1, THOC4 and CIP29, were recruited to DDX39B-DDX39A-NP complex in an ATP-dependent manner, via the interaction with DDX39B or DDX39A, followed by excess TREX-NP complexes interfere with the normal oligomerization state of NP depending on the ratio between the viral and host proteins. On the other hand, the TREX complex, an evolutionarily conserved protein complex, is responsible for the integration of several mRNA processing steps to export viral mRNA. Knockdown of TREX complex subunits significantly down-regulated viral titers and protein levels, accompanied by retention of viral mRNA in the nucleus. Taken together, screening the host factors that regulate the replication of influenza virus advances our understanding of viral pathogenesis and our findings point out a previously unclear mechanism of TREX complex function. In this study, we investigated the regulation of polymerase activity by host factors associated with vRNPs (PB2627E, PB2627K, PB2627 domain del, PB2627 CON) and provided novel insights into regulatory mechanisms of DDX39B and DDX39A during viral replication. Our results demonstrated that DDX39B and its paralog DDX39A inhibited polymerase activity via forming TREX-NP complex with concomitant effects on the oligomeric state of NP proteins. Moreover, TREX complex is necessary for expression of viral proteins. Our findings provided potential therapeutic targets for dealing with IAV infection.
Collapse
|
11
|
DDX39B drives colorectal cancer progression by promoting the stability and nuclear translocation of PKM2. Signal Transduct Target Ther 2022; 7:275. [PMID: 35973989 PMCID: PMC9381590 DOI: 10.1038/s41392-022-01096-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 06/07/2022] [Accepted: 06/28/2022] [Indexed: 12/04/2022] Open
Abstract
Metastasis is a major cause of colorectal cancer (CRC) mortality, but its molecular mechanisms are still not fully understood. Here, we show that upregulated DDX39B correlates with liver metastases and aggressive phenotypes in CRC. DDX39B is an independent prognostic factor associated with poor clinical outcome in CRC patients. We demonstrate that Sp1 potently activates DDX39B transcription by directly binding to the GC box of the DDX39B promoter in CRC cells. DDX39B overexpression augments the proliferation, migration, and invasion of CRC cells, while the opposite results are obtained in DDX39B-deficient CRC cells. Mechanistically, DDX39B interacts directly with and stabilizes PKM2 by competitively suppressing STUB1-mediated PKM2 ubiquitination and degradation. Importantly, DDX39B recruits importin α5 to accelerate the nuclear translocation of PKM2 independent of ERK1/2-mediated phosphorylation of PKM2, leading to the transactivation of oncogenes and glycolysis-related genes. Consequently, DDX39B enhances glucose uptake and lactate production to activate Warburg effect in CRC. We identify that Arg319 of DDX39B is required for PKM2 binding as well as PKM2 nuclear accumulation and for DDX39B to promote CRC growth and metastasis. In addition, blocking PKM2 nuclear translocation or treatment with glycolytic inhibitor 2-deoxy-D-glucose efficiently abolishes DDX39B-triggered malignant development in CRC. Taken together, our findings uncover a key role for DDX39B in modulating glycolytic reprogramming and aggressive progression, and implicate DDX39B as a potential therapeutic target in CRC.
Collapse
|
12
|
Magalingam KB, Somanath SD, Ramdas P, Haleagrahara N, Radhakrishnan AK. 6-Hydroxydopamine Induces Neurodegeneration in Terminally Differentiated SH-SY5Y Neuroblastoma Cells via Enrichment of the Nucleosomal Degradation Pathway: a Global Proteomics Approach. J Mol Neurosci 2022; 72:1026-1046. [PMID: 35258800 PMCID: PMC9064865 DOI: 10.1007/s12031-021-01962-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 12/22/2021] [Indexed: 01/07/2023]
Abstract
The SH-SY5Y human neuroblastoma cells have been used for decades as a cell-based model of dopaminergic neurons to explore the underlying science of cellular and molecular mechanisms of neurodegeneration in Parkinson’s disease (PD). However, data revealing the protein expression changes in 6-OHDA induced cytotoxicity in differentiated SH-SY5Y cells remain void. Therefore, we investigated the differentially regulated proteins expressed in terminally differentiated SH-SY5Y cells (differ-SH-SY5Y neural cells) exposed to 6-hydroxydopamine (6-OHDA) using the LC–MS/MS technology and construed the data using the online bioinformatics databases such as PANTHER, STRING, and KEGG. Our studies demonstrated that the neuronal development in differ-SH-SY5Y neural cells was indicated by the overexpression of proteins responsible for neurite formations such as calnexin (CANX) and calreticulin (CALR) besides significant downregulation of ribosomal proteins. The enrichment of the KEGG ribosome pathway was detected with significant downregulation (p < 0.05) of all the 21 ribosomal proteins in differ-SH-SY5Y neural cells compared with undifferentiated cells. Whereas in the PD model, the pathological changes induced by 6-OHDA were indicated by the presence of unfolded and misfolded proteins, which triggered the response of 10 kDa heat shock proteins (HSP), namely HSPE1 and HSPA9. Moreover, the 6-OHDA-induced neurodegeneration in differ-SH-SY5Y neural cells also upregulated the voltage-dependent anion-selective channel protein 1 (VDAC1) protein and enriched the KEGG systemic lupus erythematosus (SLE) pathway that was regulated by 17 histone proteins (p < 0.05) in differ-SH-SY5Y neural cells. These results suggest that the nucleosomal degradation pathway may have regulated the 6-OHDA induced neurodegeneration in PD cell-based model, which is reflected by increased apoptosis and histone release in differ-SH-SY5Y neural cells.
Collapse
Affiliation(s)
- Kasthuri Bai Magalingam
- School of Postgraduate Studies, International Medical University, Kuala Lumpur, Malaysia
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University, Malaysia, Bandar Sunway, Malaysia
| | - Sushela Devi Somanath
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Premdass Ramdas
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Nagaraja Haleagrahara
- College of Public Health, Medicine and Veterinary Sciences, James Cook University, Townsville, QLD, 4811, Australia
| | - Ammu Kutty Radhakrishnan
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University, Malaysia, Bandar Sunway, Malaysia.
- Monash-Industry Palm Oil Education and Research Platform (MIPO), Monash University Malaysia, Bandar Sunway, Selangor, Malaysia.
| |
Collapse
|
13
|
Zhang H, He C, Guo X, Fang Y, Lai Q, Wang X, Pan X, Li H, Qin K, Li A, Liu S, Li Q. DDX39B contributes to the proliferation of colorectal cancer through direct binding to CDK6/CCND1. Cell Death Dis 2022; 8:30. [PMID: 35046400 PMCID: PMC8770491 DOI: 10.1038/s41420-022-00827-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 12/01/2021] [Accepted: 01/04/2022] [Indexed: 12/12/2022]
Abstract
DDX39B (also called UAP56 or BAT1) which is a kind of DEAD-box family helicase plays pivotal roles in mRNA binding, splicing, and export. It has been found upregulated in many kinds of tumors as an oncogene. Nevertheless, the underlying molecular mechanisms of DDX39B in the proliferation of human colorectal cancer (CRC) remain fairly elusive. In our study, function experiments including the CCK8 and colony formation assay revealed that DDX39B facilitates CRC proliferation in vitro. DDX39B knockdown cells were administered for the orthotopic CRC tumor xenograft mouse model, after which tumor growth was monitored and immunohistochemistry (IHC) was performed to prove that DDX39B can also facilitates CRC proliferation in vivo. Flow cytometry demonstrated that DDX39B promotes the proliferation of CRC cells by driving the cell cycle from G0/G1 phase to the S phase. Mechanistically, RNA-binding protein immunoprecipitation-sequencing (RIP-seq) confirmed that DDX39B binds directly to the first exon of the CDK6/CCND1 pre-mRNA and upregulates their expression. Splicing experiments in vitro using a RT-PCR and gel electrophoresis assay confirmed that DDX39B promotes CDK6/CCND1 pre-mRNA splicing. Rescue experiments indicated that CDK6/CCND1 is a downstream effector of DDX39B-mediated CRC cell proliferation. Collectively, our results demonstrated that DDX39B and CDK6/CCND1 direct interactions serve as a CRC proliferation promoter, which can accelerate the G1/S phase transition to enhance CRC proliferation, and can offer novel and emerging treatment strategies targeting this cell proliferation-promoting gene.
Collapse
|
14
|
Jobbins AM, Campagne S, Weinmeister R, Lucas CM, Gosliga AR, Clery A, Chen L, Eperon LP, Hodson MJ, Hudson AJ, Allain FHT, Eperon IC. Exon-independent recruitment of SRSF1 is mediated by U1 snRNP stem-loop 3. EMBO J 2022; 41:e107640. [PMID: 34779515 PMCID: PMC8724738 DOI: 10.15252/embj.2021107640] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 12/11/2022] Open
Abstract
SRSF1 protein and U1 snRNPs are closely connected splicing factors. They both stimulate exon inclusion, SRSF1 by binding to exonic splicing enhancer sequences (ESEs) and U1 snRNPs by binding to the downstream 5' splice site (SS), and both factors affect 5' SS selection. The binding of U1 snRNPs initiates spliceosome assembly, but SR proteins such as SRSF1 can in some cases substitute for it. The mechanistic basis of this relationship is poorly understood. We show here by single-molecule methods that a single molecule of SRSF1 can be recruited by a U1 snRNP. This reaction is independent of exon sequences and separate from the U1-independent process of binding to an ESE. Structural analysis and cross-linking data show that SRSF1 contacts U1 snRNA stem-loop 3, which is required for splicing. We suggest that the recruitment of SRSF1 to a U1 snRNP at a 5'SS is the basis for exon definition by U1 snRNP and might be one of the principal functions of U1 snRNPs in the core reactions of splicing in mammals.
Collapse
Affiliation(s)
- Andrew M Jobbins
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
MRC London Institute of Medical SciencesLondonUK
- Present address:
Institute of Clinical SciencesImperial College LondonLondonUK
| | - Sébastien Campagne
- Institute of BiochemistryETH ZürichSwitzerland
- Present address:
Inserm U1212CNRS UMR5320ARNA LaboratoryBordeaux CedexFrance
| | - Robert Weinmeister
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | - Christian M Lucas
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Alison R Gosliga
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
Institut für Industrielle GenetikAbt.(eilung) SystembiologieUniversität StuttgartStuttgartGermany
| | | | - Li Chen
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Lucy P Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Mark J Hodson
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Andrew J Hudson
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | | | - Ian C Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| |
Collapse
|
15
|
Staller E, Barclay WS. Host Cell Factors That Interact with Influenza Virus Ribonucleoproteins. Cold Spring Harb Perspect Med 2021; 11:a038307. [PMID: 32988980 PMCID: PMC8559542 DOI: 10.1101/cshperspect.a038307] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Influenza viruses hijack host cell factors at each stage of the viral life cycle. After host cell entry and endosomal escape, the influenza viral ribonucleoproteins (vRNPs) are released into the cytoplasm where the classical cellular nuclear import pathway is usurped for nuclear translocation of the vRNPs. Transcription takes place inside the nucleus at active host transcription sites, and cellular mRNA export pathways are subverted for export of viral mRNAs. Newly synthesized RNP components cycle back into the nucleus using various cellular nuclear import pathways and host-encoded chaperones. Replication of the negative-sense viral RNA (vRNA) into complementary RNA (cRNA) and back into vRNA requires complex interplay between viral and host factors. Progeny vRNPs assemble at the host chromatin and subsequently exit from the nucleus-processes orchestrated by sets of host and viral proteins. Finally, several host pathways appear to play a role in vRNP trafficking from the nuclear envelope to the plasma membrane for egress.
Collapse
Affiliation(s)
- Ecco Staller
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, St. Mary's Campus, London W2 1NY, United Kingdom
| | - Wendy S Barclay
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, St. Mary's Campus, London W2 1NY, United Kingdom
| |
Collapse
|
16
|
Martelly W, Fellows B, Kang P, Vashisht A, Wohlschlegel JA, Sharma S. Synergistic roles for human U1 snRNA stem-loops in pre-mRNA splicing. RNA Biol 2021; 18:2576-2593. [PMID: 34105434 DOI: 10.1080/15476286.2021.1932360] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
During spliceosome assembly, interactions that bring the 5' and 3' ends of an intron in proximity are critical for the production of mature mRNA. Here, we report synergistic roles for the stem-loops 3 (SL3) and 4 (SL4) of the human U1 small nuclear RNA (snRNA) in maintaining the optimal U1 snRNP function, and formation of cross-intron contact with the U2 snRNP. We find that SL3 and SL4 bind distinct spliceosomal proteins and combining a U1 snRNA activity assay with siRNA-mediated knockdown, we demonstrate that SL3 and SL4 act through the RNA helicase UAP56 and the U2 protein SF3A1, respectively. In vitro analysis using UV crosslinking and splicing assays indicated that SL3 likely promotes the SL4-SF3A1 interaction leading to enhancement of A complex formation and pre-mRNA splicing. Overall, these results highlight the vital role of the distinct contacts of SL3 and SL4 in bridging the pre-mRNA bound U1 and U2 snRNPs during the early steps of human spliceosome assembly.
Collapse
Affiliation(s)
- William Martelly
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Bernice Fellows
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, USA
| | - Paul Kang
- Department of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health-Phoenix, University of Arizona, Phoenix, AZ, USA
| | - Ajay Vashisht
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Shalini Sharma
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, USA
| |
Collapse
|
17
|
Barros PO, Berthoud TK, Aloufi N, Angel JB. Soluble IL-7Rα/sCD127 in Health, Disease, and Its Potential Role as a Therapeutic Agent. Immunotargets Ther 2021; 10:47-62. [PMID: 33728276 PMCID: PMC7954429 DOI: 10.2147/itt.s264149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/16/2021] [Indexed: 01/05/2023] Open
Abstract
Soluble cytokine receptors can influence immune responses by modulating the biological functions of their respective ligands. These effects can be either agonistic or antagonistic and a number of soluble cytokine receptors have been shown to play critical roles in both maintenance of health and disease pathogenesis. Soluble IL-7Ra (sCD127) is one such example. With its impact on the IL-7/CD127 pathway, which is fundamental for the development and homeostasis of T cells, the role of sCD127 in health and disease has been extensively studied in recent years. Within this review, the role of sCD127 in maintaining host immune function is presented. Next, by addressing genetic factors affecting sCD127 expression and the associated levels of sCD127 production, the roles of sCD127 in autoimmune disease, infections and cancer are described. Finally, advances in the field of soluble cytokine therapy and the potential for sCD127 as a biomarker and therapeutic agent are discussed.
Collapse
Affiliation(s)
- Priscila O Barros
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Tamara K Berthoud
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Nawaf Aloufi
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jonathan B Angel
- Division of Infectious Diseases, Department of Medicine, University of Ottawa and the Ottawa Hospital, Ottawa, Ontario, Canada
| |
Collapse
|
18
|
Schott G, Galarza-Muñoz G, Trevino N, Chen X, Weirauch M, Gregory SG, Bradrick SS, Garcia-Blanco MA. U2AF2 binds IL7R exon 6 ectopically and represses its inclusion. RNA (NEW YORK, N.Y.) 2021; 27:rna.078279.120. [PMID: 33568552 PMCID: PMC8051268 DOI: 10.1261/rna.078279.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/02/2021] [Indexed: 06/03/2023]
Abstract
Interleukin 7 receptor α-chain is crucial for the development and maintenance of T cells and is genetically associated with autoimmune disorders including multiple sclerosis (MS), a demyelinating disease of the CNS. Exon 6 of IL7R encodes for the transmembrane domain of the receptor and is regulated by alternative splicing: inclusion or skipping of IL7R exon 6 results in membrane-bound or soluble IL7R isoforms, respectively. We previously identified a SNP (rs6897932) in IL7R exon 6, strongly associated with MS risk and showed that the risk allele (C) increases skipping of the exon, resulting in elevated levels of sIL7R. This has important pathological consequences as elevated levels of sIL7R has been shown to exacerbate the disease in the experimental autoimmune encephalomyelitis mouse model of MS. Understanding the regulation of exon 6 splicing provides important mechanistic insights into the pathogenesis of MS. Here we report two mechanisms by which IL7R exon 6 is controlled. First, a competition between PTBP1 and U2AF2 at the polypyrimidine tract (PPT) of intron 5, and second, an unexpected U2AF2-mediated assembly of spicing factors in the exon. We noted the presence of a branchpoint sequence (BPS) (TACTAAT or TACTAAC) within exon 6, which is stronger with the C allele. We also noted that the BPS is followed by a PPT and conjectured that silencing could be mediated by the binding of U2AF2 to that tract. In support of this model, we show that evolutionary conservation of the exonic PPT correlates well with the degree of alternative splicing of exon 6 in two non-human primate species and that U2AF2 binding to this PPT recruits U2 snRNP components to the exon. These observations provide the first explanation for the stronger silencing of IL7R exon 6 with the disease associated C allele at rs6897932.
Collapse
|
19
|
He C, Li A, Lai Q, Ding J, Yan Q, Liu S, Li Q. The DDX39B/FUT3/TGFβR-I axis promotes tumor metastasis and EMT in colorectal cancer. Cell Death Dis 2021; 12:74. [PMID: 33436563 PMCID: PMC7803960 DOI: 10.1038/s41419-020-03360-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 12/14/2022]
Abstract
DDX39B is a member of the DEAD box (DDX) RNA helicase family required for nearly all cellular RNA metabolic processes. The exact role and potential molecular mechanism of DDX39B in the progression of human colorectal cancer (CRC) remain to be investigated. In the present study, we demonstrate that DDX39B expression is higher in CRC tissues than in adjacent normal tissues. Gain- and loss-of-function assays revealed that DDX39B facilitates CRC metastasis in vivo and in vitro. Mechanistically, RNA-sequencing (RNA-seq) and RNA-binding protein immunoprecipitation-sequencing (RIP-seq) showed that DDX39B binds directly to the FUT3 pre-mRNA and upregulates FUT3 expression. Splicing experiments in vitro using a Minigene assay confirmed that DDX39B promotes FUT3 pre-mRNA splicing. A nuclear and cytoplasmic RNA separation assay indicates that DDX39B enhances the mRNA export of FUT3. Upregulation of FUT3 accelerates the fucosylation of TGFβR-I, which activates the TGFβ signaling pathway and eventually drives the epithelial–mesenchymal transition (EMT) program and contributes to CRC progression. These findings not only provide new insight into the role of DDX39B in mRNA splicing and export as well as in tumorigenesis, but also shed light on the effects of aberrant fucosylation on CRC progression.
Collapse
Affiliation(s)
- Chengcheng He
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Aimin Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Qiuhua Lai
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Jian Ding
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Qun Yan
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Side Liu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China.
| | - Qingyuan Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China.
| |
Collapse
|
20
|
Hsu J, Huang HT, Lee CT, Choudhuri A, Wilson NK, Abraham BJ, Moignard V, Kucinski I, Yu S, Hyde RK, Tober J, Cai X, Li Y, Guo Y, Yang S, Superdock M, Trompouki E, Calero-Nieto FJ, Ghamari A, Jiang J, Gao P, Gao L, Nguyen V, Robertson AL, Durand EM, Kathrein KL, Aifantis I, Gerber SA, Tong W, Tan K, Cantor AB, Zhou Y, Liu PP, Young RA, Göttgens B, Speck NA, Zon LI. CHD7 and Runx1 interaction provides a braking mechanism for hematopoietic differentiation. Proc Natl Acad Sci U S A 2020; 117:23626-23635. [PMID: 32883883 PMCID: PMC7519295 DOI: 10.1073/pnas.2003228117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Hematopoietic stem and progenitor cell (HSPC) formation and lineage differentiation involve gene expression programs orchestrated by transcription factors and epigenetic regulators. Genetic disruption of the chromatin remodeler chromodomain-helicase-DNA-binding protein 7 (CHD7) expanded phenotypic HSPCs, erythroid, and myeloid lineages in zebrafish and mouse embryos. CHD7 acts to suppress hematopoietic differentiation. Binding motifs for RUNX and other hematopoietic transcription factors are enriched at sites occupied by CHD7, and decreased RUNX1 occupancy correlated with loss of CHD7 localization. CHD7 physically interacts with RUNX1 and suppresses RUNX1-induced expansion of HSPCs during development through modulation of RUNX1 activity. Consequently, the RUNX1:CHD7 axis provides proper timing and function of HSPCs as they emerge during hematopoietic development or mature in adults, representing a distinct and evolutionarily conserved control mechanism to ensure accurate hematopoietic lineage differentiation.
Collapse
Affiliation(s)
- Jingmei Hsu
- Division of Hematology/Oncology, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Hsuan-Ting Huang
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Chung-Tsai Lee
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Avik Choudhuri
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138
| | - Nicola K Wilson
- Cambridge Institute for Medical Research, Department of Haematology, Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom CB2 OXY
| | - Brian J Abraham
- Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Victoria Moignard
- Cambridge Institute for Medical Research, Department of Haematology, Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom CB2 OXY
| | - Iwo Kucinski
- Cambridge Institute for Medical Research, Department of Haematology, Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom CB2 OXY
| | - Shuqian Yu
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
| | - R Katherine Hyde
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Joanna Tober
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Xiongwei Cai
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Yan Li
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Yalin Guo
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH 03756
| | - Song Yang
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Michael Superdock
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Eirini Trompouki
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Fernando J Calero-Nieto
- Cambridge Institute for Medical Research, Department of Haematology, Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom CB2 OXY
| | - Alireza Ghamari
- Division of Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Jing Jiang
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Peng Gao
- Division of Oncology and Center for Childhood Cancer Research, Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Long Gao
- Division of Oncology and Center for Childhood Cancer Research, Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Vy Nguyen
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Anne L Robertson
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Ellen M Durand
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Katie L Kathrein
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Iannis Aifantis
- Department of Pathology and Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Scott A Gerber
- Department of Genetics, Geisel School of Medicine, Lebanon, NH 03756
| | - Wei Tong
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Kai Tan
- Division of Oncology and Center for Childhood Cancer Research, Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Alan B Cantor
- Division of Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - Yi Zhou
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - P Paul Liu
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Richard A Young
- Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Berthold Göttgens
- Cambridge Institute for Medical Research, Department of Haematology, Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom CB2 OXY
| | - Nancy A Speck
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104;
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Leonard I Zon
- Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115;
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138
| |
Collapse
|
21
|
Abstract
Splicing of the precursor messenger RNA, involving intron removal and exon ligation, is mediated by the spliceosome. Together with biochemical and genetic investigations of the past four decades, structural studies of the intact spliceosome at atomic resolution since 2015 have led to mechanistic delineation of RNA splicing with remarkable insights. The spliceosome is proven to be a protein-orchestrated metalloribozyme. Conserved elements of small nuclear RNA (snRNA) constitute the splicing active site with two catalytic metal ions and recognize three conserved intron elements through duplex formation, which are delivered into the splicing active site for branching and exon ligation. The protein components of the spliceosome stabilize the conformation of the snRNA, drive spliceosome remodeling, orchestrate the movement of the RNA elements, and facilitate the splicing reaction. The overall organization of the spliceosome and the configuration of the splicing active site are strictly conserved between human and yeast.
Collapse
Affiliation(s)
- Ruixue Wan
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
| | - Rui Bai
- Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Hangzhou 310024, China
| | - Xiechao Zhan
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
- Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Hangzhou 310024, China
| |
Collapse
|
22
|
Luna R, Rondón AG, Pérez-Calero C, Salas-Armenteros I, Aguilera A. The THO Complex as a Paradigm for the Prevention of Cotranscriptional R-Loops. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:105-114. [PMID: 32493765 DOI: 10.1101/sqb.2019.84.039594] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Different proteins associate with the nascent RNA and the RNA polymerase (RNAP) to catalyze the transcription cycle and RNA export. If these processes are not properly controlled, the nascent RNA can thread back and hybridize to the DNA template forming R-loops capable of stalling replication, leading to DNA breaks. Given the transcriptional promiscuity of the genome, which leads to large amounts of RNAs from mRNAs to different types of ncRNAs, these can become a major threat to genome integrity if they form R-loops. Consequently, cells have evolved nuclear factors to prevent this phenomenon that includes THO, a conserved eukaryotic complex acting in transcription elongation and RNA processing and export that upon inactivation causes genome instability linked to R-loop accumulation. We revise and discuss here the biological relevance of THO and a number of RNA helicases, including the THO partner UAP56/DDX39B, as a paradigm of the cellular mechanisms of cotranscriptional R-loop prevention.
Collapse
Affiliation(s)
- Rosa Luna
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Ana G Rondón
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Carmen Pérez-Calero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Irene Salas-Armenteros
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| |
Collapse
|
23
|
An F-Box Protein, Mdm30, Interacts with TREX Subunit Sub2 To Regulate Cellular Abundance Cotranscriptionally in Orchestrating mRNA Export Independently of Splicing and Mitochondrial Function. Mol Cell Biol 2020; 40:MCB.00570-19. [PMID: 31932480 DOI: 10.1128/mcb.00570-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/03/2020] [Indexed: 02/02/2023] Open
Abstract
Although an F-box protein, Mdm30, is found to regulate ubiquitylation of the Sub2 component of TREX (transcription-export) complex for proteasomal degradation in stimulation of mRNA export, it remains unknown whether such ubiquitin-proteasome system (UPS) regulation of Sub2 occurs cotranscriptionally via its interaction with Mdm30. Further, it is unclear whether impaired UPS regulation of Sub2 in the absence of Mdm30 alters mRNA export via splicing defects of export factors and/or mitochondrial dynamics/function, since Sub2 controls mRNA splicing and Mdm30 regulates mitochondrial aggregation. Here, we show that Mdm30 interacts with Sub2, and temporary shutdown of Mdm30 enhances Sub2's abundance and impairs mRNA export. Likewise, Sub2's abundance is increased following transcriptional inhibition. These results support Mdm30's direct role in regulation of Sub2's cellular abundance in a transcription-dependent manner. Consistently, the chromatin-bound Sub2 level is increased in the absence of Mdm30. Further, we find that Mdm30 does not facilitate splicing of export factors. Moreover, Mdm30 does not have a dramatic effect on mitochondrial respiration/function, and mRNA export occurs in the absence of Fzo1, which is required for mitochondrial dynamics/respiration. Collective results reveal that Mdm30 interacts with Sub2 for proteasomal degradation in a transcription-dependent manner to promote mRNA export independently of splicing or mitochondrial function, thus advancing our understanding of mRNA export.
Collapse
|
24
|
Meng T, Huang R, Zeng Z, Huang Z, Yin H, Jiao C, Yan P, Hu P, Zhu X, Li Z, Song D, Zhang J, Cheng L. Identification of Prognostic and Metastatic Alternative Splicing Signatures in Kidney Renal Clear Cell Carcinoma. Front Bioeng Biotechnol 2019; 7:270. [PMID: 31681747 PMCID: PMC6803439 DOI: 10.3389/fbioe.2019.00270] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 09/30/2019] [Indexed: 12/21/2022] Open
Abstract
Background: Kidney renal clear cell carcinoma (KIRC) is the malignancy originated from the renal epithelium, with a high rate of distant metastasis. Aberrant alternative splicing (AS) of pre-mRNA are widely reported to be involved in the tumorigenesis and metastasis of multiple cancers. The aim of this study is to explore the mechanism of alternative splicing events (ASEs) underlying tumorigenesis and metastasis of KIRC. Methods: RNA-seq of 537 KIRC samples downloaded from the TCGA database and ASEs data from the TCGASpliceSeq database were used to identify ASEs in patients with KIRC. The univariate and Lasso regression analysis were used to screen the most significant overall survival-related ASEs (OS-SEs). Based on those, the OS-SEs model was proposed. The interaction network of OS-SEs and splicing factors (SFs) with absolute value of correlation coefficient value >0.750 was constructed by Pearson correlation analysis. The OS-SEs significantly related to distant metastasis and clinical stage were identified by non-parametric test, and those were also integrated into co-expression analysis with prognosis-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways identified by Gene Set Variation Analysis (GSVA). ASEs with significance were selected for multiple online database validation. Results: A total of prognostic 6,081 overall survival-related ASEs (OS-SEs) were identified by univariate Cox regression analysis and a prediction model was constructed based on 5 OS-SEs screened by Lasso regression with the Area Under Curve of 0.788. Its risk score was also illustrated to be an independent predictor, which the good reliability of the model. Among 390 identified candidate SFs, DExD-Box Helicase 39B (DDX39B) was significantly correlated with OS and metastasis. After external database validation, Retained Intron of Ras Homolog Family Member T2 (RHOT2) and T-Cell Immune Regulator 1 (TCIRG1) were identified. In the co-expression analysis, overlapped co-expression signal pathways for RHOT2 and TCIRG1 were sphingolipid metabolism and N-glycan biosynthesis. Conclusions: Based on the results of comprehensive bioinformatic analysis, we proposed that aberrant DDX39B regulated RHOT2-32938-RI and TCIRG1-17288-RI might be associated with the tumorigenesis, metastasis, and poor prognosis of KIRC via sphingolipid metabolism or N-glycan biosynthesis pathway.
Collapse
Affiliation(s)
- Tong Meng
- Division of Spine, Department of Orthopedics, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China.,Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration, Tongji University, Ministry of Education, Shanghai, China.,Department of Orthopedics, School of Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Runzhi Huang
- Division of Spine, Department of Orthopedics, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China.,Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration, Tongji University, Ministry of Education, Shanghai, China
| | - Zhiwei Zeng
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zongqiang Huang
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Huabin Yin
- Department of Orthopedics, School of Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - ChenChen Jiao
- Department of Pathology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Penghui Yan
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Peng Hu
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaolong Zhu
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhenyu Li
- Department of Prevention, Tongji University School of Medicine, Tongji University, Shanghai, China
| | - Dianwen Song
- Department of Orthopedics, School of Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Jie Zhang
- Division of Spine, Department of Orthopedics, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China.,Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration, Tongji University, Ministry of Education, Shanghai, China.,Department of Prevention, Tongji University School of Medicine, Tongji University, Shanghai, China
| | - Liming Cheng
- Division of Spine, Department of Orthopedics, Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China.,Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration, Tongji University, Ministry of Education, Shanghai, China
| |
Collapse
|
25
|
Awasthi S, Verma M, Mahesh A, K Khan MI, Govindaraju G, Rajavelu A, Chavali PL, Chavali S, Dhayalan A. DDX49 is an RNA helicase that affects translation by regulating mRNA export and the levels of pre-ribosomal RNA. Nucleic Acids Res 2019; 46:6304-6317. [PMID: 29618122 PMCID: PMC6158705 DOI: 10.1093/nar/gky231] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/28/2018] [Indexed: 12/19/2022] Open
Abstract
Among the proteins predicted to be a part of the DExD box RNA helicase family, the functions of DDX49 are unknown. Here, we characterize the enzymatic activities and functions of DDX49 by comparing its properties with the well-studied RNA helicase, DDX39B. We find that DDX49 exhibits a robust ATPase and RNA helicase activity, significantly higher than that of DDX39B. DDX49 is required for the efficient export of poly (A)+ RNA from nucleus in a splicing-independent manner. Furthermore, DDX49 is a resident protein of nucleolus and regulates the steady state levels of pre-ribosomal RNA by regulating its transcription and stability. These dual functions of regulating mRNA export and pre-ribosomal RNA levels enable DDX49 to modulate global translation. Phenotypically, DDX49 promotes proliferation and colony forming potential of cells. Strikingly, DDX49 is significantly elevated in diverse cancer types suggesting that the increased abundance of DDX49 has a role in oncogenic transformation of cells. Taken together, this study shows the physiological role of DDX49 in regulating distinct steps of mRNA and pre-ribosomal RNA metabolism and hence translation and potential pathological role of its dysregulation, especially in cancers.
Collapse
Affiliation(s)
- Sharad Awasthi
- Department of Biotechnology, Pondicherry University, Puducherry 605 014, India
| | - Mamta Verma
- Department of Biotechnology, Pondicherry University, Puducherry 605 014, India
| | - Arun Mahesh
- Department of Biotechnology, Pondicherry University, Puducherry 605 014, India
| | - Mohd Imran K Khan
- Department of Biotechnology, Pondicherry University, Puducherry 605 014, India
| | - Gayathri Govindaraju
- Bacterial and Parasite Disease Biology, Rajiv Gandhi Center for Biotechnology, Trivandrum 695 014, India
| | - Arumugam Rajavelu
- Bacterial and Parasite Disease Biology, Rajiv Gandhi Center for Biotechnology, Trivandrum 695 014, India
| | - Pavithra L Chavali
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Sreenivas Chavali
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Arunkumar Dhayalan
- Department of Biotechnology, Pondicherry University, Puducherry 605 014, India
| |
Collapse
|
26
|
Overlapping motifs on the herpes viral proteins ICP27 and ORF57 mediate interactions with the mRNA export adaptors ALYREF and UIF. Sci Rep 2018; 8:15005. [PMID: 30301920 PMCID: PMC6177440 DOI: 10.1038/s41598-018-33379-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022] Open
Abstract
The TREX complex mediates the passage of bulk cellular mRNA export to the nuclear export factor TAP/NXF1 via the export adaptors ALYREF or UIF, which appear to act in a redundant manner. TREX complex recruitment to nascent RNA is coupled with 5′ capping, splicing and polyadenylation. Therefore to facilitate expression from their intronless genes, herpes viruses have evolved a mechanism to circumvent these cellular controls. Central to this process is a protein from the conserved ICP27 family, which binds viral transcripts and cellular TREX complex components including ALYREF. Here we have identified a novel interaction between HSV-1 ICP27 and an N-terminal domain of UIF in vivo, and used NMR spectroscopy to locate the UIF binding site within an intrinsically disordered region of ICP27. We also characterized the interaction sites of the ICP27 homolog ORF57 from KSHV with UIF and ALYREF using NMR, revealing previously unidentified binding motifs. In both ORF57 and ICP27 the interaction sites for ALYREF and UIF partially overlap, suggestive of mutually exclusive binding. The data provide a map of the binding sites responsible for promoting herpes virus mRNA export, enabling future studies to accurately probe these interactions and reveal the functional consequences for UIF and ALYREF redundancy.
Collapse
|
27
|
Awasthi S, Chakrapani B, Mahesh A, Chavali PL, Chavali S, Dhayalan A. DDX39B promotes translation through regulation of pre-ribosomal RNA levels. RNA Biol 2018; 15:1157-1166. [PMID: 30176153 DOI: 10.1080/15476286.2018.1517011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
DDX39B, a DExD RNA helicase, is known to be involved in various cellular processes such as mRNA export, splicing and translation. Previous studies showed that the overexpression of DDX39B promotes the global translation but inhibits the mRNA export in a dominant negative manner. This presents a conundrum as to how DDX39B overexpression would increase the global translation if it inhibits the nuclear export of mRNAs. We resolve this by showing that DDX39B affects the levels of pre-ribosomal RNA by regulating its stability as well as synthesis. Furthermore, DDX39B promotes proliferation and colony forming potential of cells and its levels are significantly elevated in diverse cancer types. Thus, increase in DDX39B enhances global translation and cell proliferation through upregulation of pre-ribosomal RNA. This highlights a possible mechanism by which dysregulation of DDX39B expression could lead to oncogenesis.
Collapse
Affiliation(s)
- Sharad Awasthi
- a Department of Biotechnology , Pondicherry University , Puducherry , India
| | - Baskar Chakrapani
- a Department of Biotechnology , Pondicherry University , Puducherry , India
| | - Arun Mahesh
- a Department of Biotechnology , Pondicherry University , Puducherry , India
| | - Pavithra L Chavali
- b Structural Studies Division , MRC Laboratory of Molecular Biology , Cambridge , UK
| | - Sreenivas Chavali
- b Structural Studies Division , MRC Laboratory of Molecular Biology , Cambridge , UK
| | - Arunkumar Dhayalan
- a Department of Biotechnology , Pondicherry University , Puducherry , India
| |
Collapse
|
28
|
Chiba S, Hill-Batorski L, Neumann G, Kawaoka Y. The Cellular DExD/H-Box RNA Helicase UAP56 Co-localizes With the Influenza A Virus NS1 Protein. Front Microbiol 2018; 9:2192. [PMID: 30258431 PMCID: PMC6144874 DOI: 10.3389/fmicb.2018.02192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/27/2018] [Indexed: 11/13/2022] Open
Abstract
UAP56, a member of the DExD/H-box RNA helicase family, is essential for pre-mRNA splicing and mRNA export in eukaryotic cells. In influenza A virus-infected cells, UAP56 mediates viral mRNA nuclear export, facilitates viral ribonucleoprotein complex formation through direct interaction with the viral nucleoprotein, and may indirectly affect antiviral host responses by binding to and/or facilitating the activation of the antiviral host factors MxA and PKR. Here, we demonstrate that UAP56 also co-localizes with the influenza A viral NS1 protein, which counteracts host cell innate immune responses stimulated by virus infection. The UAP56-NS1 association relies on the RNA-binding residues R38 and K41 in NS1 and may be mediated by single-stranded RNA. UAP56 association with NS1 does not affect the NS1-mediated downregulation of cellular innate immune pathways in reporter gene assays, leaving in question the exact biological role and relevance of the UAP56-NS1 association.
Collapse
Affiliation(s)
- Shiho Chiba
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Lindsay Hill-Batorski
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Gabriele Neumann
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Yoshihiro Kawaoka
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
- Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| |
Collapse
|
29
|
Cui X, Han W, Li J, Feng R, Zhou Z, Han J, Li M, Wang S, Zhang W, Lei Q, Zhang J, Liu Y, Hu Y. Heat shock factor 4 regulates the expression of HSP25 and alpha B-crystallin by associating with DEXD/H-box RNA helicase UAP56. Cell Stress Chaperones 2018; 23:571-579. [PMID: 29164525 PMCID: PMC6045540 DOI: 10.1007/s12192-017-0865-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 11/08/2017] [Accepted: 11/10/2017] [Indexed: 11/24/2022] Open
Abstract
Heat shock factor 4 controls the transcription of small heat shock proteins (e.g., HSP25, alpha B-cyrstallin, and r-crystallin), that play important roles in modulating lens proteostasis. However, the molecular mechanism underlying HSF4-mediated transcription is still unclear. Using yeast two hybrid, we found that HSF4 interacts with the ATP-dependent DEXD/H-box RNA helicase UAP56, and their interaction in lens epithelial cell line was further confirmed by GST-pull down assay. UAP56 is a vital regulator of pre-mRNA splicing and mature mRNA nuclear export. The immunofluorescence assay showed that HSF4 and UBA56 co-localize with each other in the nucleus of lens epithelial cells. Ectopic UAP56 upregulated HSF4-controlled HSP25 and alpha B-crystallin proteins expression, while knocking down UAP56 by shRNA reversed it. Moreover, UAP56 interacts with and facilitates the nuclear exportation of HSP25 and alpha B-crystallin mRNA without impacting their total mRNA expression level. In lens tissues, both UAP56 and HSF4 are expressed in the same nucleus of lens fiber cells, and their expression levels are simultaneously reduced with fiber cell maturation. Taken together, these data suggested that UAP56 is a novel regulator of HSF4 and might upregulate HSF4's downstream mRNA maturation and nuclear exportation.
Collapse
Affiliation(s)
- Xiukun Cui
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Wenxiu Han
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Jing Li
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Riping Feng
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Zheng Zhou
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - JiuLi Han
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Mengyuan Li
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Shuangfeng Wang
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Wanting Zhang
- Kaifeng Key Laboratory of Cataract and Myopia, Institute of Eye disease, Kaifeng Central Hospital, Kaifeng, China
| | - Qin Lei
- Kaifeng Key Laboratory of Cataract and Myopia, Institute of Eye disease, Kaifeng Central Hospital, Kaifeng, China
| | - Jun Zhang
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China
| | - Yutiao Liu
- Department of Cell biology and Anatomy, Augusta University, Augusta, GA, USA
| | - Yanzhong Hu
- National Joint Laboratory For Antibody Drug Enginerring, Henan-international Union Laboratory of Antibody Medicine, Department of Cell Biology and Genetics, School of Basic Medical Science, Henan University, Kaifeng, Henan, 475014, China.
- Kaifeng Key Laboratory of Cataract and Myopia, Institute of Eye disease, Kaifeng Central Hospital, Kaifeng, China.
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
|
32
|
Shi Y. The Spliceosome: A Protein-Directed Metalloribozyme. J Mol Biol 2017; 429:2640-2653. [PMID: 28733144 DOI: 10.1016/j.jmb.2017.07.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 11/15/2022]
Abstract
Pre-mRNA splicing is executed by the ribonucleoprotein machinery spliceosome. Nearly 40 years after the discovery of pre-mRNA splicing, the atomic structure of the spliceosome has finally come to light. Four distinct conformational states of the yeast spliceosome have been captured at atomic or near-atomic resolutions. Two catalytic metal ions at the active site are specifically coordinated by the U6 small nuclear RNA (snRNA) and catalyze both the branching reaction and the exon ligation. Of the three snRNAs in the fully assembled spliceosome, U5 and U6, along with 30 contiguous nucleotides of U2 at its 5'-end, remain structurally rigid throughout the splicing reaction. The rigidity of these RNA elements is safeguarded by Prp8 and 16 core protein components, which maintain the same overall conformation in all structurally characterized spliceosomes during the splicing reaction. Only the sequences downstream of nucleotide 30 of U2 snRNA are mobile; their movement, directed by the protein components, delivers the intron branch site into the close proximity of the 5'-splice site for the branching reaction. A set of additional structural rearrangement is required for exon ligation, and the lariat junction is moved out of the active site for recruitment of the 3'-splice site and 3'-exon. The spliceosome is proven to be a protein-directed metalloribozyme.
Collapse
Affiliation(s)
- Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Xihu District, Hangzhou 310064, Zhejiang Province, Province, China.
| |
Collapse
|
33
|
Abstract
TRanscription and EXport (TREX) is a conserved multisubunit complex essential for embryogenesis, organogenesis and cellular differentiation throughout life. By linking transcription, mRNA processing and export together, it exerts a physiologically vital role in the gene expression pathway. In addition, this complex prevents DNA damage and regulates the cell cycle by ensuring optimal gene expression. As the extent of TREX activity in viral infections, amyotrophic lateral sclerosis and cancer emerges, the need for a greater understanding of TREX function becomes evident. A complete elucidation of the composition, function and interactions of the complex will provide the framework for understanding the molecular basis for a variety of diseases. This review details the known composition of TREX, how it is regulated and its cellular functions with an emphasis on mammalian systems.
Collapse
|
34
|
Galarza-Muñoz G, Briggs FBS, Evsyukova I, Schott-Lerner G, Kennedy EM, Nyanhete T, Wang L, Bergamaschi L, Widen SG, Tomaras GD, Ko DC, Bradrick SS, Barcellos LF, Gregory SG, Garcia-Blanco MA. Human Epistatic Interaction Controls IL7R Splicing and Increases Multiple Sclerosis Risk. Cell 2017; 169:72-84.e13. [PMID: 28340352 DOI: 10.1016/j.cell.2017.03.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 09/18/2016] [Accepted: 03/02/2017] [Indexed: 12/18/2022]
Abstract
Multiple sclerosis (MS) is an autoimmune disorder where T cells attack neurons in the central nervous system (CNS) leading to demyelination and neurological deficits. A driver of increased MS risk is the soluble form of the interleukin-7 receptor alpha chain gene (sIL7R) produced by alternative splicing of IL7R exon 6. Here, we identified the RNA helicase DDX39B as a potent activator of this exon and consequently a repressor of sIL7R, and we found strong genetic association of DDX39B with MS risk. Indeed, we showed that a genetic variant in the 5' UTR of DDX39B reduces translation of DDX39B mRNAs and increases MS risk. Importantly, this DDX39B variant showed strong genetic and functional epistasis with allelic variants in IL7R exon 6. This study establishes the occurrence of biological epistasis in humans and provides mechanistic insight into the regulation of IL7R exon 6 splicing and its impact on MS risk.
Collapse
Affiliation(s)
- Gaddiel Galarza-Muñoz
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Center for RNA Biology, Duke University, Durham, NC 27710, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Farren B S Briggs
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Irina Evsyukova
- Center for RNA Biology, Duke University, Durham, NC 27710, USA
| | - Geraldine Schott-Lerner
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Edward M Kennedy
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tinashe Nyanhete
- Department of Immunology, Duke University Durham, NC 27710, USA; Department of Surgery, Duke University Durham, NC 27710, USA
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Laura Bergamaschi
- Duke Molecular Physiology Institute, Duke University, Durham, NC 27701, USA
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Georgia D Tomaras
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Durham, NC 27710, USA; Department of Surgery, Duke University Durham, NC 27710, USA
| | - Dennis C Ko
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center; Durham, NC 27710, USA
| | - Shelton S Bradrick
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Center for RNA Biology, Duke University, Durham, NC 27710, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Lisa F Barcellos
- Division of Epidemiology, School of Public Health, University of California Berkeley, Berkeley, CA 94720, USA
| | - Simon G Gregory
- Duke Molecular Physiology Institute, Duke University, Durham, NC 27701, USA; Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Mariano A Garcia-Blanco
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Center for RNA Biology, Duke University, Durham, NC 27710, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| |
Collapse
|
35
|
Sørensen BB, Ehrnsberger HF, Esposito S, Pfab A, Bruckmann A, Hauptmann J, Meister G, Merkl R, Schubert T, Längst G, Melzer M, Grasser M, Grasser KD. The Arabidopsis THO/TREX component TEX1 functionally interacts with MOS11 and modulates mRNA export and alternative splicing events. PLANT MOLECULAR BIOLOGY 2017; 93:283-298. [PMID: 28004241 DOI: 10.1007/s11103-016-0561-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/10/2016] [Indexed: 05/25/2023]
Abstract
We identify proteins that associate with the THO core complex, and show that the TEX1 and MOS11 components functionally interact, affecting mRNA export and splicing as well as plant development. TREX (TRanscription-EXport) is a multiprotein complex that plays a central role in the coordination of synthesis, processing and nuclear export of mRNAs. Using targeted proteomics, we identified proteins that associate with the THO core complex of Arabidopsis TREX. In addition to the RNA helicase UAP56 and the mRNA export factors ALY2-4 and MOS11 we detected interactions with the mRNA export complex TREX-2 and multiple spliceosomal components. Plants defective in the THO component TEX1 or in the mRNA export factor MOS11 (orthologue of human CIP29) are mildly affected. However, tex1 mos11 double-mutant plants show marked defects in vegetative and reproductive development. In tex1 plants, the levels of tasiRNAs are reduced, while miR173 levels are decreased in mos11 mutants. In nuclei of mos11 cells increased mRNA accumulation was observed, while no mRNA export defect was detected with tex1 cells. Nevertheless, in tex1 mos11 double-mutants, the mRNA export defect was clearly enhanced relative to mos11. The subnuclear distribution of TEX1 substantially overlaps with that of splicing-related SR proteins and in tex1 plants the ratio of certain alternative splicing events is altered. Our results demonstrate that Arabidopsis TEX1 and MOS11 are involved in distinct steps of the biogenesis of mRNAs and small RNAs, and that they interact regarding some aspects, but act independently in others.
Collapse
Affiliation(s)
- Brian B Sørensen
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Hans F Ehrnsberger
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Silvia Esposito
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Alexander Pfab
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Astrid Bruckmann
- Department for Biochemistry I, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Judith Hauptmann
- Department for Biochemistry I, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Gunter Meister
- Department for Biochemistry I, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Rainer Merkl
- Department for Biochemistry II, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Thomas Schubert
- Department for Biochemistry III, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Gernot Längst
- Department for Biochemistry III, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstr. 3, 06466, Stadt Seeland, Germany
| | - Marion Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
| | - Klaus D Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
| |
Collapse
|
36
|
Nakata D, Nakao S, Nakayama K, Araki S, Nakayama Y, Aparicio S, Hara T, Nakanishi A. The RNA helicase DDX39B and its paralog DDX39A regulate androgen receptor splice variant AR-V7 generation. Biochem Biophys Res Commun 2016; 483:271-276. [PMID: 28025139 DOI: 10.1016/j.bbrc.2016.12.153] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 12/17/2022]
Abstract
Mounting evidence suggests that constitutively active androgen receptor (AR) splice variants, typified by AR-V7, are associated with poor prognosis and resistance to androgen deprivation therapy in prostate cancer patients. However, mechanisms governing the generation of AR splice variants are not fully understood. In this study, we aimed to investigate the dynamics of AR splice variant generation using the JDCaP prostate cancer model that expresses AR splice variants under androgen depletion. Microarray analysis of JDCaP xenografts before and after expression of AR splice variants suggested that dysregulation of RNA processing pathways is likely involved in AR splice variant generation. To explore factors contributing to generation of AR-V7 mRNA, we conducted a focused RNA interference screen in AR-V7-positive JDCaP-hr cells using an shRNA library targeting spliceosome-related genes. This screen identified DDX39B as a regulator of AR-V7 mRNA expression. Simultaneous knockdown of DDX39B and its paralog DDX39A drastically and selectively downregulated AR-V7 mRNA expression in multiple AR-V7-positive prostate cancer cell lines. DDX39B was upregulated in relapsed JDCaP xenografts expressing AR splice variants, suggesting its role in expression of AR splice variants. Taken together, our findings offer insight into the mechanisms of AR splice variant generation and identify DDX39 as a potential drug target for the treatment of AR splice variant-positive prostate cancer.
Collapse
Affiliation(s)
- Daisuke Nakata
- Oncology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Shoichi Nakao
- Shonan Incubation Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan; Integrated Technology Research Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Kazuhide Nakayama
- Oncology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Shinsuke Araki
- Oncology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan; Shonan Incubation Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Yusuke Nakayama
- Shonan Incubation Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan; Integrated Technology Research Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Samuel Aparicio
- Shonan Incubation Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan; BC Cancer Agency, Department of Molecular Oncology, Vancouver, BC, V5Z 1L3, Canada; University of British Columbia, Department of Pathology and Laboratory Medicine, Vancouver, BC, V6T 2B5, Canada
| | - Takahito Hara
- Oncology Drug Discovery Unit, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan.
| | - Atsushi Nakanishi
- Shonan Incubation Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan; Integrated Technology Research Laboratories, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan.
| |
Collapse
|
37
|
De I, Schmitzová J, Pena V. The organization and contribution of helicases to RNA splicing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:259-74. [PMID: 26874649 DOI: 10.1002/wrna.1331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 12/27/2022]
Abstract
Splicing is an essential step of gene expression. It occurs in two consecutive chemical reactions catalyzed by a large protein-RNA complex named the spliceosome. Assembled on the pre-mRNA substrate from five small nuclear proteins, the spliceosome acts as a protein-controlled ribozyme to catalyze the two reactions and finally dissociates into its components, which are re-used for a new round of splicing. Upon following this cyclic pathway, the spliceosome undergoes numerous intermediate stages that differ in composition as well as in their internal RNA-RNA and RNA-protein contacts. The driving forces and control mechanisms of these remodeling processes are provided by specific molecular motors called RNA helicases. While eight spliceosomal helicases are present in all organisms, higher eukaryotes contain five additional ones potentially required to drive a more intricate splicing pathway and link it to an RNA metabolism of increasing complexity. Spliceosomal helicases exhibit a notable structural diversity in their accessory domains and overall architecture, in accordance with the diversity of their task-specific functions. This review summarizes structure-function knowledge about all spliceosomal helicases, including the latter five, which traditionally are treated separately from the conserved ones. The implications of the structural characteristics of helicases for their functions, as well as for their structural communication within the multi-subunits environment of the spliceosome, are pointed out.
Collapse
Affiliation(s)
- Inessa De
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Jana Schmitzová
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Vladimir Pena
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| |
Collapse
|
38
|
Zheng X, Cho S, Moon H, Loh TJ, Jang HN, Shen H. Detecting RNA-Protein Interaction Using End-Labeled Biotinylated RNA Oligonucleotides and Immunoblotting. Methods Mol Biol 2016; 1421:35-44. [PMID: 26965255 DOI: 10.1007/978-1-4939-3591-8_4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
RNA-protein interaction can be detected by RNA pull-down and immunoblotting methods. Here, we describe a method to detect RNA-protein interaction using RNA pull down and to identify the proteins that are pulled-down by the RNA using immunoblotting. In this protocol, RNAs with specific sequences are biotinylated and immobilized onto Streptavidin beads, which are then used to pull down interacting proteins from cellular extracts. The presence of a specific protein is subsequently verified by SDS- polyacrylamide gel electrophoresis and immunoblotting with antibodies. Interactions between the SMN RNA and the PSF protein and between the caspase-2 RNA and the SRSF3 protein (SRp20) in nuclear extract prepared from HeLa cells are illustrated as examples.
Collapse
Affiliation(s)
- Xuexiu Zheng
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea
| | - Sunghee Cho
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea
| | - Heegyum Moon
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea
| | - Tiing Jen Loh
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea
| | - Ha Na Jang
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea
| | - Haihong Shen
- School of Life Science, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 500-712, South Korea.
| |
Collapse
|
39
|
Liu YC, Cheng SC. Functional roles of DExD/H-box RNA helicases in Pre-mRNA splicing. J Biomed Sci 2015; 22:54. [PMID: 26173448 PMCID: PMC4503299 DOI: 10.1186/s12929-015-0161-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/29/2015] [Indexed: 01/30/2023] Open
Abstract
Splicing of precursor mRNA takes place via two consecutive steps of transesterification catalyzed by a large ribonucleoprotein complex called the spliceosome. The spliceosome is assembled through ordered binding to the pre-mRNA of five small nuclear RNAs and numerous protein factors, and is disassembled after completion of the reaction to recycle all components. Throughout the splicing cycle, the spliceosome changes its structure, rearranging RNA-RNA, RNA-protein and protein-protein interactions, for positioning and repositioning of splice sites. DExD/H-box RNA helicases play important roles in mediating structural changes of the spliceosome by unwinding of RNA duplexes or disrupting RNA-protein interactions. DExD/H-box proteins are also implicated in the fidelity control of the splicing process at various steps. This review summarizes the functional roles of DExD/H-box proteins in pre-mRNA splicing according to studies conducted mostly in yeast and will discuss the concept of the complicated splicing reaction based on recent findings.
Collapse
Affiliation(s)
- Yen-Chi Liu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, 115, Republic of China.
| | - Soo-Chen Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, 115, Republic of China.
| |
Collapse
|
40
|
Muto M, Mori M, Hiwasa T, Takiguchi M, Iwadate Y, Uzawa A, Uchida T, Masuda H, Sugimoto K, Kuwabara S. Novel serum autoantibodies against talin1 in multiple sclerosis: Possible pathogenetic roles of the antibodies. J Neuroimmunol 2015; 284:30-6. [PMID: 26025055 DOI: 10.1016/j.jneuroim.2015.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/21/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
Abstract
In the pathogenesis of multiple sclerosis (MS), B cell/antibody-related mechanisms have recently received attention. To investigate the role of autoantibody in MS, we performed SEREX which can identify autoantibody cyclopedically. We identified serum antibodies against cytoskeletal protein talin1, and the levels of whom were remarkably higher in 39 MS than 43 normal controls (P < 0.01) and 35 disease controls (P = 0.06), and in MS patients without oligoclonal bands than ones with them. Moreover, we found negative-correlations between serum anti-talin1 antibody and IgG index in MS (P = 0.03). Anti-talin1 antibody exists in MS patients' sera, which may have some protective factor.
Collapse
Affiliation(s)
- Mayumi Muto
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masahiro Mori
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan.
| | - Takaki Hiwasa
- Department of Biochemistry and Genetics, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masaki Takiguchi
- Department of Biochemistry and Genetics, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasuo Iwadate
- Department of Neurological Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Akiyuki Uzawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tomohiko Uchida
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hiroki Masuda
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kazuo Sugimoto
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| |
Collapse
|
41
|
Lento S, Brioschi M, Barcella S, Nasim MT, Ghilardi S, Barbieri SS, Tremoli E, Banfi C. Proteomics of tissue factor silencing in cardiomyocytic cells reveals a new role for this coagulation factor in splicing machinery control. J Proteomics 2015; 119:75-89. [DOI: 10.1016/j.jprot.2015.01.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 01/08/2015] [Accepted: 01/25/2015] [Indexed: 12/12/2022]
|
42
|
Sharma S, Wongpalee SP, Vashisht A, Wohlschlegel JA, Black DL. Stem-loop 4 of U1 snRNA is essential for splicing and interacts with the U2 snRNP-specific SF3A1 protein during spliceosome assembly. Genes Dev 2015; 28:2518-31. [PMID: 25403181 PMCID: PMC4233244 DOI: 10.1101/gad.248625.114] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The pairing of 5′ and 3′ splice sites across an intron is a critical step in spliceosome formation and its regulation. Sharma et al. report a new interaction between stem–loop 4 (SL4) of the U1 snRNA, which recognizes the 5′ splice, and a component of the U2 snRNP complex, which assembles across the intron at the 3′ splice site. U1-SL4 interacts with the SF3A1 protein of the U2 snRNP, and this interaction occurs within prespliceosomal complexes assembled on the pre-mRNA. The pairing of 5′ and 3′ splice sites across an intron is a critical step in spliceosome formation and its regulation. Interactions that bring the two splice sites together during spliceosome assembly must occur with a high degree of specificity and fidelity to allow expression of functional mRNAs and make particular alternative splicing choices. Here, we report a new interaction between stem–loop 4 (SL4) of the U1 snRNA, which recognizes the 5′ splice site, and a component of the U2 small nuclear ribonucleoprotein particle (snRNP) complex, which assembles across the intron at the 3′ splice site. Using a U1 snRNP complementation assay, we found that SL4 is essential for splicing in vivo. The addition of free U1-SL4 to a splicing reaction in vitro inhibits splicing and blocks complex assembly prior to formation of the prespliceosomal A complex, indicating a requirement for a SL4 contact in spliceosome assembly. To characterize the interactions of this RNA structure, we used a combination of stable isotope labeling by amino acids in cell culture (SILAC), biotin/Neutravidin affinity pull-down, and mass spectrometry. We show that U1-SL4 interacts with the SF3A1 protein of the U2 snRNP. We found that this interaction between the U1 snRNA and SF3A1 occurs within prespliceosomal complexes assembled on the pre-mRNA. Thus, SL4 of the U1 snRNA is important for splicing, and its interaction with SF3A1 mediates contact between the 5′ and 3′ splice site complexes within the assembling spliceosome.
Collapse
Affiliation(s)
- Shalini Sharma
- Department of Basic Medical Sciences, University of Arizona, College of Medicine-Phoenix, Phoenix, Arizona 85004, USA; Department of Microbiology, Immunology, and Molecular Genetics
| | | | | | | | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
| |
Collapse
|
43
|
Umate P, Tuteja N, Tuteja R. Genome-wide comprehensive analysis of human helicases. Commun Integr Biol 2014. [DOI: 10.4161/cib.13844] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
44
|
Zheng X, Cho S, Moon H, Loh TJ, Oh HK, Green MR, Shen H. Polypyrimidine tract binding protein inhibits IgM pre-mRNA splicing by diverting U2 snRNA base-pairing away from the branch point. RNA (NEW YORK, N.Y.) 2014; 20:440-446. [PMID: 24572809 PMCID: PMC3964906 DOI: 10.1261/rna.043737.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
The mouse immunoglobulin (IgM) pre-mRNA contains a splicing inhibitor that bears multiple binding sites for the splicing repressor polypyrimidine tract binding protein (PTB). Here we show that the inhibitor directs assembly of an ATP-dependent complex that contains PTB and U1 and U2 small nuclear RNAs (snRNAs). Unexpectedly, although U2 snRNA is present in the inhibitor complex, it is not base-paired to the branch point. We present evidence that inhibitor-bound PTB contacts U2 snRNA to promote base-pairing to an adjacent branch point-like sequence within the inhibitor, thereby preventing the U2 snRNA-branch point interaction and resulting in splicing repression. Our studies reveal a novel mechanism by which PTB represses splicing.
Collapse
Affiliation(s)
- Xuexiu Zheng
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Sunghee Cho
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Heegyum Moon
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Tiing Jen Loh
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Huyn Kyung Oh
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Michael R. Green
- Howard Hughes Medical Institute and Programs in Gene Function and Expression and Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Haihong Shen
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| |
Collapse
|
45
|
Abstract
Superfamily 2 helicase proteins are ubiquitous in RNA biology and have an extraordinarily broad set of functional roles. Central among these roles are the promotion of rearrangements of structured RNAs and the remodeling of ribonucleoprotein complexes (RNPs), allowing formation of native RNA structure or progression through a functional cycle of structures. Although all superfamily 2 helicases share a conserved helicase core, they are divided evolutionarily into several families, and it is principally proteins from three families, the DEAD-box, DEAH/RHA, and Ski2-like families, that function to manipulate structured RNAs and RNPs. Strikingly, there are emerging differences in the mechanisms of these proteins, both between families and within the largest family (DEAD-box), and these differences appear to be tuned to their RNA or RNP substrates and their specific roles. This review outlines basic mechanistic features of the three families and surveys individual proteins and the current understanding of their biological substrates and mechanisms.
Collapse
Affiliation(s)
- Inga Jarmoskaite
- Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712; ,
| | | |
Collapse
|
46
|
Cho S, Moon H, Loh TJ, Oh HK, Cho S, Choy HE, Song WK, Chun JS, Zheng X, Shen H. hnRNP M facilitates exon 7 inclusion of SMN2 pre-mRNA in spinal muscular atrophy by targeting an enhancer on exon 7. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:306-15. [PMID: 24533984 DOI: 10.1016/j.bbagrm.2014.02.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/07/2014] [Accepted: 02/10/2014] [Indexed: 12/24/2022]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disease, which causes death of motor neurons in the anterior horn of the spinal cord. Genetic cause of SMA is the deletion or mutation of SMN1 gene, which encodes the SMN protein. Although SMA patients include SMN2 gene, a duplicate of SMN1 gene, predominant production of exon 7 skipped isoform from SMN2 pre-mRNA, fails to rescue SMA patients. Here we show that hnRNP M, a member of hnRNP protein family, when knocked down, promotes exon 7 skipping of both SMN2 and SMN1 pre-mRNA. By contrast, overexpression of hnRNP M promotes exon 7 inclusion of both SMN2 and SMN1 pre-mRNA. Significantly, hnRNP M promotes exon 7 inclusion in SMA patient cells. Thus, we conclude that hnRNP M promotes exon 7 inclusion of both SMN1 and SMN2 pre-mRNA. We also demonstrate that hnRNP M contacts an enhancer on exon 7, which was previously shown to provide binding site for tra2β. We present evidence that hnRNP M and tra2β contact overlapped sequence on exon 7 but with slightly different RNA sequence requirements. In addition, hnRNP M promotes U2AF65 recruitment on the flanking intron of exon 7. We conclude that hnRNP M promotes exon 7 inclusion of SMN1 and SMN2 pre-mRNA through targeting an enhancer on exon 7 through recruiting U2AF65. Our results provide a clue that hnRNP M is a potential therapeutic target for SMA.
Collapse
Affiliation(s)
- Sunghee Cho
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Heegyum Moon
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Tiing Jen Loh
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Huyn Kyung Oh
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Sungchan Cho
- Bio-Therapeutics Research Institute, Korea Research Institute of Bioscience and Biotechnology, Chungcheongbuk-do 363-883, Republic of Korea
| | - Hyon E Choy
- Department of Microbiology, Chonnam National University Medical School, Dong-gu, Gwangju, Republic of Korea
| | - Woo Keun Song
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Jang-Soo Chun
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Xuexiu Zheng
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
| | - Haihong Shen
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
| |
Collapse
|
47
|
Jang HN, Lee M, Loh TJ, Choi SW, Oh HK, Moon H, Cho S, Hong SE, Kim DH, Sheng Z, Green MR, Park D, Zheng X, Shen H. Exon 9 skipping of apoptotic caspase-2 pre-mRNA is promoted by SRSF3 through interaction with exon 8. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1839:25-32. [PMID: 24321384 DOI: 10.1016/j.bbagrm.2013.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/14/2013] [Accepted: 11/26/2013] [Indexed: 01/24/2023]
Abstract
Alternative splicing plays an important role in gene expression by producing different proteins from a gene. Caspase-2 pre-mRNA produces anti-apoptotic Casp-2S and pro-apoptotic Casp-2L proteins through exon 9 inclusion or skipping. However, the molecular mechanisms of exon 9 splicing are not well understood. Here we show that knockdown of SRSF3 (also known as SRp20) with siRNA induced significant increase of endogenous exon 9 inclusion. In addition, overexpression of SRSF3 promoted exon 9 skipping. Thus we conclude that SRSF3 promotes exon 9 skipping. In order to understand the functional target of SRSF3 on caspase-2 pre-mRNA, we performed substitution and deletion mutagenesis on the potential SRSF3 binding sites that were predicted from previous reports. We demonstrate that substitution mutagenesis of the potential SRSF3 binding site on exon 8 severely disrupted the effects of SRSF3 on exon 9 skipping. Furthermore, with the approach of RNA pulldown and immunoblotting analysis we show that SRSF3 interacts with the potential SRSF3 binding RNA sequence on exon 8 but not with the mutant RNA sequence. In addition, we show that a deletion of 26nt RNA from 5' end of exon 8, a 33nt RNA from 3' end of exon 10 and a 2225nt RNA from intron 9 did not compromise the function of SRSF3 on exon 9 splicing. Therefore we conclude that SRSF3 promotes exon 9 skipping of caspase-2 pre-mRNA by interacting with exon 8. Our results reveal a novel mechanism of caspase-2 pre-mRNA splicing.
Collapse
Affiliation(s)
- Ha Na Jang
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Minho Lee
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Tiing Jen Loh
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Seung-Woo Choi
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Hyun Kyung Oh
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Heegyum Moon
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Sunghee Cho
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Seong-Eui Hong
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Do Han Kim
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Zhi Sheng
- Virginia Tech Carilion Research Institute, Roanoke, VA, 24016, USA; Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michael R Green
- Howard Hughes Medical Institute and Programs in Gene Function and Expression and Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Daeho Park
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Xuexiu Zheng
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Haihong Shen
- School of life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| |
Collapse
|
48
|
Koodathingal P, Staley JP. Splicing fidelity: DEAD/H-box ATPases as molecular clocks. RNA Biol 2013; 10:1073-9. [PMID: 23770752 PMCID: PMC3849154 DOI: 10.4161/rna.25245] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/29/2013] [Accepted: 06/01/2013] [Indexed: 12/28/2022] Open
Abstract
The spliceosome discriminates against suboptimal substrates, both during assembly and catalysis, thereby enhancing specificity during pre-mRNA splicing. Central to such fidelity mechanisms are a conserved subset of the DEAD- and DEAH-box ATPases, which belong to a superfamily of proteins that mediate RNP rearrangements in almost all RNA-dependent processes in the cell. Through an investigation of the mechanisms contributing to the specificity of 5' splice site cleavage, two related reports, one from our lab and the other from the Cheng lab, have provided insights into fidelity mechanisms utilized by the spliceosome. In our work, we found evidence for a kinetic proofreading mechanism in splicing in which the DEAH-box ATPase Prp16 discriminates against substrates undergoing slow 5' splice site cleavage. Additionally, our study revealed that discriminated substrates are discarded through a general spliceosome disassembly pathway, mediated by another DEAH-box ATPase Prp43. In their work, Tseng et al. described the underlying molecular events through which Prp16 discriminates against a splicing substrate during 5' splice site cleavage. Here, we present a synthesis of these two studies and, additionally, provide the first biochemical evidence for discrimination of a suboptimal splicing substrate just prior to 5' splice site cleavage. Together, these findings support a general mechanism for a ubiquitous superfamily of ATPases in enhancing specificity during RNA-dependent processes in the cell.
Collapse
Affiliation(s)
- Prakash Koodathingal
- Department of Molecular Genetics and Cell Biology; The University of Chicago; Chicago, IL USA
| | - Jonathan P. Staley
- Department of Molecular Genetics and Cell Biology; The University of Chicago; Chicago, IL USA
| |
Collapse
|
49
|
Kammel C, Thomaier M, Sørensen BB, Schubert T, Längst G, Grasser M, Grasser KD. Arabidopsis DEAD-box RNA helicase UAP56 interacts with both RNA and DNA as well as with mRNA export factors. PLoS One 2013; 8:e60644. [PMID: 23555998 PMCID: PMC3608606 DOI: 10.1371/journal.pone.0060644] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/01/2013] [Indexed: 01/30/2023] Open
Abstract
The DEAD-box protein UAP56 (U2AF65-associcated protein) is an RNA helicase that in yeast and metazoa is critically involved in mRNA splicing and export. In Arabidopsis, two adjacent genes code for an identical UAP56 protein, and both genes are expressed. In case one of the genes is inactivated by a T-DNA insertion, wild type transcript level is maintained by the other intact gene. In contrast to other organisms that are severely affected by elevated UAP56 levels, Arabidopsis plants that overexpress UAP56 have wild type appearance. UAP56 localises predominantly to euchromatic regions of Arabidopsis nuclei, and associates with genes transcribed by RNA polymerase II independently from the presence of introns, while it is not detected at non-transcribed loci. Biochemical characterisation revealed that in addition to ssRNA and dsRNA, UAP56 interacts with dsDNA, but not with ssDNA. Moreover, the enzyme displays ATPase activity that is stimulated by RNA and dsDNA and it has ATP-dependent RNA helicase activity unwinding dsRNA, whereas it does not unwind dsDNA. Protein interaction studies showed that UAP56 directly interacts with the mRNA export factors ALY2 and MOS11, suggesting that it is involved in mRNA export from plant cell nuclei.
Collapse
Affiliation(s)
- Christine Kammel
- Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Maren Thomaier
- Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Brian B. Sørensen
- Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Thomas Schubert
- Institute for Biochemistry III, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Gernot Längst
- Institute for Biochemistry III, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Marion Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
- * E-mail: (MG); (KDG)
| | - Klaus D. Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
- * E-mail: (MG); (KDG)
| |
Collapse
|
50
|
Lee KM, Tarn WY. Coupling pre-mRNA processing to transcription on the RNA factory assembly line. RNA Biol 2013; 10:380-90. [PMID: 23392244 DOI: 10.4161/rna.23697] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
It has been well-documented that nuclear processing of primary transcripts of RNA polymerase II occurs co-transcriptionally and is functionally coupled to transcription. Moreover, increasing evidence indicates that transcription influences pre-mRNA splicing and even several post-splicing RNA processing events. In this review, we discuss the issues of how RNA polymerase II modulates co-transcriptional RNA processing events via its carboxyl terminal domain, and the protein domains involved in coupling of transcription and RNA processing events. In addition, we describe how transcription influences the expression or stability of mRNAs through the formation of distinct mRNP complexes. Finally, we delineate emerging findings that chromatin modifications function in the regulation of RNA processing steps, especially splicing, in addition to transcription. Overall, we provide a comprehensive view that transcription could integrate different control systems, from epigenetic to post-transcriptional control, for efficient gene expression.
Collapse
Affiliation(s)
- Kuo-Ming Lee
- Institute of Biomedical Sciences; Academia Sinica; Taipei, Taiwan
| | | |
Collapse
|