1
|
Su Y, Wu J, Chen W, Shan J, Chen D, Zhu G, Ge S, Liu Y. Spliceosomal snRNAs, the Essential Players in pre-mRNA Processing in Eukaryotic Nucleus: From Biogenesis to Functions and Spatiotemporal Characteristics. Adv Biol (Weinh) 2024:e2400006. [PMID: 38797893 DOI: 10.1002/adbi.202400006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/30/2024] [Indexed: 05/29/2024]
Abstract
Spliceosomal small nuclear RNAs (snRNAs) are a fundamental class of non-coding small RNAs abundant in the nucleoplasm of eukaryotic cells, playing a crucial role in splicing precursor messenger RNAs (pre-mRNAs). They are transcribed by DNA-dependent RNA polymerase II (Pol II) or III (Pol III), and undergo subsequent processing and 3' end cleavage to become mature snRNAs. Numerous protein factors are involved in the transcription initiation, elongation, termination, splicing, cellular localization, and terminal modification processes of snRNAs. The transcription and processing of snRNAs are regulated spatiotemporally by various mechanisms, and the homeostatic balance of snRNAs within cells is of great significance for the growth and development of organisms. snRNAs assemble with specific accessory proteins to form small nuclear ribonucleoprotein particles (snRNPs) that are the basal components of spliceosomes responsible for pre-mRNA maturation. This article provides an overview of the biological functions, biosynthesis, terminal structure, and tissue-specific regulation of snRNAs.
Collapse
Affiliation(s)
- Yuan Su
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Jiaming Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Wei Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Junling Shan
- Department of basic medicine, Guangxi Medical University of Nursing College, Nanning, Guangxi, 530021, China
| | - Dan Chen
- Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, Guangxi, 530011, China
| | - Guangyu Zhu
- Guangxi Medical University Hospital of Stomatology, Nanning, Guangxi, 530021, China
| | - Shengchao Ge
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Yunfeng Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| |
Collapse
|
2
|
Marullo R, Rutherford SC, Revuelta MV, Zamponi N, Culjkovic-Kraljacic B, Kotlov N, Di Siervi N, Lara-Garcia J, Allan JN, Ruan J, Furman RR, Chen Z, Shore TB, Phillips AA, Mayer S, Hsu J, van Besien K, Leonard JP, Borden KL, Inghirami G, Martin P, Cerchietti L. XPO1 Enables Adaptive Regulation of mRNA Export Required for Genotoxic Stress Tolerance in Cancer Cells. Cancer Res 2024; 84:101-117. [PMID: 37801604 PMCID: PMC10758694 DOI: 10.1158/0008-5472.can-23-1992] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/08/2023] [Accepted: 10/03/2023] [Indexed: 10/08/2023]
Abstract
Exportin-1 (XPO1), the main soluble nuclear export receptor in eukaryotic cells, is frequently overexpressed in diffuse large B-cell lymphoma (DLBCL). A selective XPO1 inhibitor, selinexor, received approval as single agent for relapsed or refractory (R/R) DLBCL. Elucidating the mechanisms by which XPO1 overexpression supports cancer cells could facilitate further clinical development of XPO1 inhibitors. We uncovered here that XPO1 overexpression increases tolerance to genotoxic stress, leading to a poor response to chemoimmunotherapy. Upon DNA damage induced by MYC expression or exogenous compounds, XPO1 bound and exported EIF4E and THOC4 carrying DNA damage repair mRNAs, thereby increasing synthesis of DNA damage repair proteins under conditions of increased turnover. Consequently, XPO1 inhibition decreased the capacity of lymphoma cells to repair DNA damage and ultimately resulted in increased cytotoxicity. In a phase I clinical trial conducted in R/R DLBCL, the combination of selinexor with second-line chemoimmunotherapy was tolerated with early indication of efficacy. Overall, this study reveals that XPO1 overexpression plays a critical role in the increased tolerance of cancer cells to DNA damage while providing new insights to optimize the clinical development of XPO1 inhibitors. SIGNIFICANCE XPO1 regulates the dynamic ribonucleoprotein nuclear export in response to genotoxic stress to support tolerance and can be targeted to enhance the sensitivity of cancer cells to endogenous and exogenous DNA damage. See related commentary by Knittel and Reinhardt, p. 3.
Collapse
Affiliation(s)
- Rossella Marullo
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Sarah C. Rutherford
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Maria V. Revuelta
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Nahuel Zamponi
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Biljana Culjkovic-Kraljacic
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Canada
| | | | - Nicolás Di Siervi
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Juan Lara-Garcia
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - John N. Allan
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Jia Ruan
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Richard R. Furman
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Zhengming Chen
- Division of Biostatistics, Population Health Sciences Department, Weill Cornell Medicine, New York, New York
| | - Tsiporah B. Shore
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Adrienne A. Phillips
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Sebastian Mayer
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Jingmei Hsu
- New York University Grossman School of Medicine, New York, New York
| | | | - John P. Leonard
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Katherine L.B. Borden
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Canada
| | - Giorgio Inghirami
- Pathology and Laboratory Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Peter Martin
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| | - Leandro Cerchietti
- Division of Hematology and Oncology, Medicine Department, Weill Cornell Medicine and NewYork-Presbyterian Hospital, New York, New York
| |
Collapse
|
3
|
Takeiwa T, Ikeda K, Horie K, Inoue S. Role of RNA binding proteins of the Drosophila behavior and human splicing (DBHS) family in health and cancer. RNA Biol 2024; 21:1-17. [PMID: 38551131 PMCID: PMC10984136 DOI: 10.1080/15476286.2024.2332855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2024] [Indexed: 04/02/2024] Open
Abstract
RNA-binding proteins (RBPs) play crucial roles in the functions and homoeostasis of various tissues by regulating multiple events of RNA processing including RNA splicing, intracellular RNA transport, and mRNA translation. The Drosophila behavior and human splicing (DBHS) family proteins including PSF/SFPQ, NONO, and PSPC1 are ubiquitously expressed RBPs that contribute to the physiology of several tissues. In mammals, DBHS proteins have been reported to contribute to neurological diseases and play crucial roles in cancers, such as prostate, breast, and liver cancers, by regulating cancer-specific gene expression. Notably, in recent years, multiple small molecules targeting DBHS family proteins have been developed for application as cancer therapeutics. This review provides a recent overview of the functions of DBHS family in physiology and pathophysiology, and discusses the application of DBHS family proteins as promising diagnostic and therapeutic targets for cancers.
Collapse
Affiliation(s)
- Toshihiko Takeiwa
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi-ku, Tokyo, Japan
| | - Kazuhiro Ikeda
- Division of Systems Medicine & Gene Therapy, Faculty of Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Kuniko Horie
- Division of Systems Medicine & Gene Therapy, Faculty of Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Satoshi Inoue
- Department of Systems Aging Science and Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi-ku, Tokyo, Japan
- Division of Systems Medicine & Gene Therapy, Faculty of Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| |
Collapse
|
4
|
Cristi AC, Rapuri S, Coyne AN. Nuclear pore complex and nucleocytoplasmic transport disruption in neurodegeneration. FEBS Lett 2023; 597:2546-2566. [PMID: 37657945 PMCID: PMC10612469 DOI: 10.1002/1873-3468.14729] [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: 06/25/2023] [Revised: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023]
Abstract
Nuclear pore complexes (NPCs) play a critical role in maintaining the equilibrium between the nucleus and cytoplasm, enabling bidirectional transport across the nuclear envelope, and are essential for proper nuclear organization and gene regulation. Perturbations in the regulatory mechanisms governing NPCs and nuclear envelope homeostasis have been implicated in the pathogenesis of several neurodegenerative diseases. The ESCRT-III pathway emerges as a critical player in the surveillance and preservation of well-assembled, functional NPCs, as well as nuclear envelope sealing. Recent studies have provided insights into the involvement of nuclear ESCRT-III in the selective reduction of specific nucleoporins associated with neurodegenerative pathologies. Thus, maintaining quality control of the nuclear envelope and NPCs represents a pivotal element in the pathological cascade leading to neurodegenerative diseases. This review describes the constituents of the nuclear-cytoplasmic transport machinery, encompassing the nuclear envelope, NPC, and ESCRT proteins, and how their structural and functional alterations contribute to the development of neurodegenerative diseases.
Collapse
Affiliation(s)
- América Chandía Cristi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| | - Sampath Rapuri
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| | - Alyssa N Coyne
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| |
Collapse
|
5
|
Rahman MM, van Oosterom F, Enow JA, Hossain M, Gutierrez-Jensen AD, Cashen M, Everts A, Lowe K, Kilbourne J, Daggett-Vondras J, Karr TL, McFadden G. Nuclear Export Inhibitor Selinexor Enhances Oncolytic Myxoma Virus Therapy against Cancer. CANCER RESEARCH COMMUNICATIONS 2023; 3:952-968. [PMID: 37377603 PMCID: PMC10234290 DOI: 10.1158/2767-9764.crc-22-0483] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/08/2023] [Accepted: 05/11/2023] [Indexed: 06/29/2023]
Abstract
Oncolytic viruses exploited for cancer therapy have been developed to selectively infect, replicate, and kill cancer cells to inhibit tumor growth. However, in some cancer cells, oncolytic viruses are often limited in completing their full replication cycle, forming progeny virions, and/or spreading in the tumor bed because of the heterogeneous cell types within the tumor bed. Here, we report that the nuclear export pathway regulates oncolytic myxoma virus (MYXV) infection and cytoplasmic viral replication in a subclass of human cancer cell types where viral replication is restricted. Inhibition of the XPO-1 (exportin 1) nuclear export pathway with nuclear export inhibitors can overcome this restriction by trapping restriction factors in the nucleus and allow significantly enhanced viral replication and killing of cancer cells. Furthermore, knockdown of XPO-1 significantly enhanced MYXV replication in restrictive human cancer cells and reduced the formation of antiviral granules associated with RNA helicase DHX9. Both in vitro and in vivo, we demonstrated that the approved XPO1 inhibitor drug selinexor enhances the replication of MYXV and kills diverse human cancer cells. In a xenograft tumor model in NSG mice, combination therapy with selinexor plus MYXV significantly reduced the tumor burden and enhanced the survival of animals. In addition, we performed global-scale proteomic analysis of nuclear and cytosolic proteins in human cancer cells to identify the host and viral proteins that were upregulated or downregulated by different treatments. These results indicate, for the first time, that selinexor in combination with oncolytic MYXV can be used as a potential new therapy. Significance We demonstrated that a combination of nuclear export inhibitor selinexor and oncolytic MYXV significantly enhanced viral replication, reduced cancer cell proliferation, reduced tumor burden, and enhanced the overall survival of animals. Thus, selinexor and oncolytic MYXV can be used as potential new anticancer therapy.
Collapse
Affiliation(s)
- Masmudur M. Rahman
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Fleur van Oosterom
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Junior A. Enow
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Maksuda Hossain
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Ami D. Gutierrez-Jensen
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Mackenzie Cashen
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Anne Everts
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Kenneth Lowe
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Jacquelyn Kilbourne
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Juliane Daggett-Vondras
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Timothy L. Karr
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
| | - Grant McFadden
- Center for Immunotherapy, Vaccines, and Virotherapy, Biodesign Institute, Arizona State University, Tempe, Arizona
- School of Life Sciences, Arizona State University, Tempe, Arizona
| |
Collapse
|
6
|
Jeandard D, Smirnova A, Fasemore AM, Coudray L, Entelis N, Förstner K, Tarassov I, Smirnov A. CoLoC-seq probes the global topology of organelle transcriptomes. Nucleic Acids Res 2022; 51:e16. [PMID: 36537202 PMCID: PMC9943681 DOI: 10.1093/nar/gkac1183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Proper RNA localisation is essential for physiological gene expression. Various kinds of genome-wide approaches permit to comprehensively profile subcellular transcriptomes. Among them, cell fractionation methods, that couple RNase treatment of isolated organelles to the sequencing of protected transcripts, remain most widely used, mainly because they do not require genetic modification of the studied system and can be easily implemented in any cells or tissues, including in non-model species. However, they suffer from numerous false-positives since incompletely digested contaminant RNAs can still be captured and erroneously identified as resident transcripts. Here we introduce Controlled Level of Contamination coupled to deep sequencing (CoLoC-seq) as a new subcellular transcriptomics approach that efficiently bypasses this caveat. CoLoC-seq leverages classical enzymatic kinetics and tracks the depletion dynamics of transcripts in a gradient of an exogenously added RNase, with or without organellar membranes. By means of straightforward mathematical modelling, CoLoC-seq infers the localisation topology of RNAs and robustly distinguishes between genuinely resident, luminal transcripts and merely abundant surface-attached contaminants. Our generic approach performed well on human mitochondria and is in principle applicable to other membrane-bounded organelles, including plastids, compartments of the vacuolar system, extracellular vesicles, and viral particles.
Collapse
Affiliation(s)
| | | | | | - Léna Coudray
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
| | - Nina Entelis
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
| | - Konrad U Förstner
- ZB MED – Information Centre for Life Sciences, Cologne, D-50931, Germany,TH Köln – University of Applied Sciences, Faculty of Information Science and Communication Studies, Institute of Information Science, Cologne, D-50678, Germany
| | - Ivan Tarassov
- UMR7156 – Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, F-67000, France
| | | |
Collapse
|
7
|
Klama S, Hirsch AG, Schneider UM, Zander G, Seel A, Krebber H. A guard protein mediated quality control mechanism monitors 5'-capping of pre-mRNAs. Nucleic Acids Res 2022; 50:11301-11314. [PMID: 36305816 PMCID: PMC9638935 DOI: 10.1093/nar/gkac952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 09/30/2022] [Accepted: 10/12/2022] [Indexed: 07/26/2023] Open
Abstract
Efficient gene expression requires properly matured mRNAs for functional transcript translation. Several factors including the guard proteins monitor maturation and act as nuclear retention factors for unprocessed pre-mRNAs. Here we show that the guard protein Npl3 monitors 5'-capping. In its absence, uncapped transcripts resist degradation, because the Rat1-Rai1 5'-end degradation factors are not efficiently recruited to these faulty transcripts. Importantly, in npl3Δ, these improperly capped transcripts escape this quality control checkpoint and leak into the cytoplasm. Our data suggest a model in which Npl3 associates with the Rai1 bound pre-mRNAs. In case the transcript was properly capped and is thus CBC (cap binding complex) bound, Rai1 dissociates from Npl3 allowing the export factor Mex67 to interact with this guard protein and support nuclear export. In case Npl3 does not detect proper capping through CBC attachment, Rai1 binding persists and Rat1 can join this 5'-complex to degrade the faulty transcript.
Collapse
Affiliation(s)
| | | | - Ulla M Schneider
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen 37077, Germany
| | - Gesa Zander
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen 37077, Germany
| | - Anika Seel
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen 37077, Germany
| | - Heike Krebber
- To whom correspondence should be addressed. Tel: +49 551 39 33801; Fax: +49 551 39 33805;
| |
Collapse
|
8
|
Transcriptomic analysis of ribosome biogenesis and pre-rRNA processing during growth stress in Entamoeba histolytica. Exp Parasitol 2022; 239:108308. [PMID: 35718007 DOI: 10.1016/j.exppara.2022.108308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 05/27/2022] [Accepted: 06/14/2022] [Indexed: 11/24/2022]
Abstract
Ribosome biogenesis, a multi-step process involving transcription, modification, folding and processing of rRNA, is the major consumer of cellular energy. It involves sequential assembly of ribosomal proteins (RP)s via more than 200 ribogenesis factors. Unlike model organisms where transcription of rRNA and RP genes slows down during stress, in Entamoeba histolytica, pre-rRNA synthesis continues, and unprocessed pre-rRNA accumulates. Northern hybridization from different spacer regions depicted the accumulation of unprocessed intermediates during stress. To gain insight into the vast repertoire of ribosome biogenesis factors and understand the major components playing role during stress we computationally identified ribosome biogenesis factors in E. histolytica. Of the ∼279 Saccharomyces cerevisiae proteins, we could only find 188 proteins in E. histolytica. Some of the proteins missing in E. histolytica were also missing in humans. A number of proteins represented by multiple genes in S. cerevisiae had a single copy in E. histolytica. Interestingly E. histolytica lacked mitochondrial ribosome biogenesis factors and had far less RNase components compared to S. cerevisiae. Transcriptomic studies revealed the differential regulation of ribosomal factors both in serum starved and RRP6 down-regulation conditions. These included the NEP1 and TSR3 proteins that chemically modify 18S-rRNA. Pre-rRNA precursors accumulate upon downregulation of the latter proteins in S. cerevisiae and humans. These data reveal the major factors that regulate pre-rRNA processing during stress in E. histolytica and provide the first complete repertoire of ribosome biogenesis factors in this early-branching protist.
Collapse
|
9
|
Nataraj NB, Noronha A, Lee JS, Ghosh S, Mohan Raju HR, Sekar A, Zuckerman B, Lindzen M, Tarcitano E, Srivastava S, Selitrennik M, Livneh I, Drago-Garcia D, Rueda O, Caldas C, Lev S, Geiger T, Ciechanover A, Ulitsky I, Seger R, Ruppin E, Yarden Y. Nucleoporin-93 reveals a common feature of aggressive breast cancers: robust nucleocytoplasmic transport of transcription factors. Cell Rep 2022; 38:110418. [PMID: 35196484 PMCID: PMC8957480 DOI: 10.1016/j.celrep.2022.110418] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 10/14/2021] [Accepted: 02/01/2022] [Indexed: 12/14/2022] Open
Abstract
By establishing multi-omics pipelines, we uncover overexpression and gene copy-number alterations of nucleoporin-93 (NUP93), a nuclear pore component, in aggressive human mammary tumors. NUP93 overexpression enhances transendothelial migration and matrix invasion in vitro, along with tumor growth and metastasis in animal models. These findings are supported by analyses of two sets of naturally occurring mutations: rare oncogenic mutations and inactivating familial nephrotic syndrome mutations. Mechanistically, NUP93 binds with importins, boosts nuclear transport of importins' cargoes, such as β-catenin, and activates MYC. Likewise, NUP93 overexpression enhances the ultimate nuclear transport step shared by additional signaling pathways, including TGF-β/SMAD and EGF/ERK. The emerging addiction to nuclear transport exposes vulnerabilities of NUP93-overexpressing tumors. Congruently, myristoylated peptides corresponding to the nuclear translocation signals of SMAD and ERK can inhibit tumor growth and metastasis. Our study sheds light on an emerging hallmark of advanced tumors, which derive benefit from robust nucleocytoplasmic transport.
Collapse
Affiliation(s)
| | - Ashish Noronha
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Joo Sang Lee
- Cancer Data Science Lab, National Cancer Institute, NIH, Rockville, MD, USA
| | - Soma Ghosh
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Harsha Raj Mohan Raju
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Arunachalam Sekar
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Binyamin Zuckerman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Moshit Lindzen
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Emilio Tarcitano
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Swati Srivastava
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Selitrennik
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ido Livneh
- Technion Integrated Cancer Center (TICC) and the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Diana Drago-Garcia
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Oscar Rueda
- Cancer Research UK Cambridge Institute, University of Cambridge and the Cambridge Cancer Centre, Department of Oncology, Cambridge, UK
| | - Carlos Caldas
- Cancer Research UK Cambridge Institute, University of Cambridge and the Cambridge Cancer Centre, Department of Oncology, Cambridge, UK
| | - Sima Lev
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tamar Geiger
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel; Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Aaron Ciechanover
- Technion Integrated Cancer Center (TICC) and the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Rony Seger
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Eytan Ruppin
- Cancer Data Science Lab, National Cancer Institute, NIH, Rockville, MD, USA
| | - Yosef Yarden
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel.
| |
Collapse
|
10
|
Alemasova EE, Naumenko KN, Sukhanova MV, Lavrik OI. Role of YB-1 in Regulation of Poly(ADP-Ribosylation) Catalyzed by Poly(ADP-Ribose) Polymerases. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:S32-S0. [PMID: 35501985 DOI: 10.1134/s0006297922140048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 06/14/2023]
Abstract
Poly(ADP-ribosyl)ation is a post-translational modification of proteins that performs an essential regulatory function in the cellular response to DNA damage. The key enzyme synthesizing poly(ADP-ribose) (PAR) in the cells is poly(ADP-ribose) polymerase 1 (PARP1). Understanding the mechanisms of the PARP1 activity regulation within the cells is necessary for development of the PARP1-targeted antitumor therapy. This review is devoted to the studies of the role of the RNA-binding protein YB-1 in the PARP1-catalyzed PARylation. The mechanisms of PARP1 activity stimulation by YB-1 protein can possibly be extended to other RNA-binding proteins involved in the maintenance of the genome stability.
Collapse
Affiliation(s)
- Elizaveta E Alemasova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Konstantin N Naumenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Maria V Sukhanova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Olga I Lavrik
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
- Novosibirsk State University, Novosibirsk, 630090, Russia
| |
Collapse
|
11
|
Nuclear export of the pre-60S ribosomal subunit through single nuclear pores observed in real time. Nat Commun 2021; 12:6211. [PMID: 34707094 PMCID: PMC8551241 DOI: 10.1038/s41467-021-26323-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/02/2021] [Indexed: 11/08/2022] Open
Abstract
Ribosomal biogenesis has been studied by biochemical, genetic and electron microscopic approaches, but live cell data on the in vivo kinetics are still missing. Here we analyse the export kinetics of the large ribosomal subunit (pre-60S particle) through single NPCs in human cells. We established a stable cell line co-expressing Halo-tagged eIF6 and GFP-fused NTF2 to simultaneously label pre-60S particles and NPCs, respectively. By combining single molecule tracking and super resolution confocal microscopy we visualize the dynamics of single pre-60S particles during export through single NPCs. For export events, maximum particle accumulation is found in the centre of the pore, while unsuccessful export terminates within the nuclear basket. The export has a single rate limiting step and a duration of ∼24 milliseconds. Only about 1/3 of attempted export events are successful. Our results show that the mass flux through a single NPC can reach up to ~125 MDa·s-1 in vivo.
Collapse
|
12
|
Aquino GRR, Hackert P, Krogh N, Pan KT, Jaafar M, Henras AK, Nielsen H, Urlaub H, Bohnsack KE, Bohnsack MT. The RNA helicase Dbp7 promotes domain V/VI compaction and stabilization of inter-domain interactions during early 60S assembly. Nat Commun 2021; 12:6152. [PMID: 34686661 PMCID: PMC8536713 DOI: 10.1038/s41467-021-26208-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 09/22/2021] [Indexed: 02/07/2023] Open
Abstract
Early pre-60S ribosomal particles are poorly characterized, highly dynamic complexes that undergo extensive rRNA folding and compaction concomitant with assembly of ribosomal proteins and exchange of assembly factors. Pre-60S particles contain numerous RNA helicases, which are likely regulators of accurate and efficient formation of appropriate rRNA structures. Here we reveal binding of the RNA helicase Dbp7 to domain V/VI of early pre-60S particles in yeast and show that in the absence of this protein, dissociation of the Npa1 scaffolding complex, release of the snR190 folding chaperone, recruitment of the A3 cluster factors and binding of the ribosomal protein uL3 are impaired. uL3 is critical for formation of the peptidyltransferase center (PTC) and is responsible for stabilizing interactions between the 5′ and 3′ ends of the 25S, an essential pre-requisite for subsequent pre-60S maturation events. Highlighting the importance of pre-ribosome remodeling by Dbp7, our data suggest that in the absence of Dbp7 or its catalytic activity, early pre-ribosomal particles are targeted for degradation. Early steps of large 60S ribosomal subunit biogenesis are not well understood. Here, the authors combine biochemical experiments with protein-RNA crosslinking and mass spectrometry to show that the RNA helicase Dbp7 is key player during early 60S ribosomal assembly. Dbp7 regulates a series of events driving compaction of domain V/VI in early pre60S ribosomal particles.
Collapse
Affiliation(s)
- Gerald Ryan R Aquino
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark
| | - Kuan-Ting Pan
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Hematology/Oncology, Department of Medicine II, Johann Wolfgang Goethe University, 60590, Frankfurt am Main, Germany.,Frankfurt Cancer Institute, Goethe University, 60596, Frankfurt am Main, Germany
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark.,Genomics Group, Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Institute for Clinical Chemistry, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany. .,Göttingen Centre for Molecular Biosciences, Georg-August-University, Justus-von-Liebig Weg 11, 37077, Göttingen, Germany.
| |
Collapse
|
13
|
Birikmen M, Bohnsack KE, Tran V, Somayaji S, Bohnsack MT, Ebersberger I. Tracing Eukaryotic Ribosome Biogenesis Factors Into the Archaeal Domain Sheds Light on the Evolution of Functional Complexity. Front Microbiol 2021; 12:739000. [PMID: 34603269 PMCID: PMC8481954 DOI: 10.3389/fmicb.2021.739000] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/17/2021] [Indexed: 01/23/2023] Open
Abstract
Ribosome assembly is an essential and carefully choreographed cellular process. In eukaryotes, several 100 proteins, distributed across the nucleolus, nucleus, and cytoplasm, co-ordinate the step-wise assembly of four ribosomal RNAs (rRNAs) and approximately 80 ribosomal proteins (RPs) into the mature ribosomal subunits. Due to the inherent complexity of the assembly process, functional studies identifying ribosome biogenesis factors and, more importantly, their precise functions and interplay are confined to a few and very well-established model organisms. Although best characterized in yeast (Saccharomyces cerevisiae), emerging links to disease and the discovery of additional layers of regulation have recently encouraged deeper analysis of the pathway in human cells. In archaea, ribosome biogenesis is less well-understood. However, their simpler sub-cellular structure should allow a less elaborated assembly procedure, potentially providing insights into the functional essentials of ribosome biogenesis that evolved long before the diversification of archaea and eukaryotes. Here, we use a comprehensive phylogenetic profiling setup, integrating targeted ortholog searches with automated scoring of protein domain architecture similarities and an assessment of when search sensitivity becomes limiting, to trace 301 curated eukaryotic ribosome biogenesis factors across 982 taxa spanning the tree of life and including 727 archaea. We show that both factor loss and lineage-specific modifications of factor function modulate ribosome biogenesis, and we highlight that limited sensitivity of the ortholog search can confound evolutionary conclusions. Projecting into the archaeal domain, we find that only few factors are consistently present across the analyzed taxa, and lineage-specific loss is common. While members of the Asgard group are not special with respect to their inventory of ribosome biogenesis factors (RBFs), they unite the highest number of orthologs to eukaryotic RBFs in one taxon. Using large ribosomal subunit maturation as an example, we demonstrate that archaea pursue a simplified version of the corresponding steps in eukaryotes. Much of the complexity of this process evolved on the eukaryotic lineage by the duplication of ribosomal proteins and their subsequent functional diversification into ribosome biogenesis factors. This highlights that studying ribosome biogenesis in archaea provides fundamental information also for understanding the process in eukaryotes.
Collapse
Affiliation(s)
- Mehmet Birikmen
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Vinh Tran
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Sharvari Somayaji
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Germany
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt, Germany.,Senckenberg Biodiversity and Climate Research Center (S-BIK-F), Frankfurt, Germany.,LOEWE Center for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
| |
Collapse
|
14
|
Tartakoff AM, Chen L, Raghavachari S, Gitiforooz D, Dhinakaran A, Ni CL, Pasadyn C, Mahabeleshwar GH, Pasadyn V, Woolford JL. The nucleolus as a polarized coaxial cable in which the rDNA axis is surrounded by dynamic subunit-specific phases. Curr Biol 2021; 31:2507-2519.e4. [PMID: 33862007 PMCID: PMC8222187 DOI: 10.1016/j.cub.2021.03.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/18/2021] [Accepted: 03/11/2021] [Indexed: 12/24/2022]
Abstract
In ribosomal DNA (rDNA) repeats, sequences encoding small-subunit (SSU) rRNA precede those encoding large-subunit (LSU) rRNAs. Processing the composite transcript and subunit assembly requires >100 subunit-specific nucleolar assembly factors (AFs). To investigate the functional organization of the nucleolus, we localized AFs in S. cerevisiae in which the rDNA axis was "linearized" to reduce its dimensionality, thereby revealing its coaxial organization. In this situation, rRNA synthesis and processing continue. The axis is embedded in an inner layer/phase of SSU AFs that is surrounded by an outer layer/phase of LSU AFs. When subunit production is inhibited, subsets of AFs differentially relocate between the inner and outer layers, as expected if there is a cycle of repeated relocation whereby "latent" AFs become "operative" when recruited to nascent subunits. Recognition of AF cycling and localization of segments of rRNA make it possible to infer the existence of assembly intermediates that span between the inner and outer layers and to chart the cotranscriptional assembly of each subunit. AF cycling also can explain how having more than one protein phase in the nucleolus makes possible "vectorial 2-phase partitioning" as a driving force for relocation of nascent rRNPs. Because nucleoplasmic AFs are also present in the outer layer, we propose that critical surface remodeling occurs at this site, thereby partitioning subunit precursors into the nucleoplasm for post-transcriptional maturation. Comparison to observations on higher eukaryotes shows that the coaxial paradigm is likely to be applicable for the many other organisms that have rDNA repeats.
Collapse
Affiliation(s)
- Alan M Tartakoff
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA.
| | - Lan Chen
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Shashank Raghavachari
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Daria Gitiforooz
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Akshyasri Dhinakaran
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Chun-Lun Ni
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | | | - Ganapati H Mahabeleshwar
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Vanessa Pasadyn
- Department of Pathology and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| |
Collapse
|
15
|
Aquino GRR, Krogh N, Hackert P, Martin R, Gallesio JD, van Nues RW, Schneider C, Watkins NJ, Nielsen H, Bohnsack KE, Bohnsack MT. RNA helicase-mediated regulation of snoRNP dynamics on pre-ribosomes and rRNA 2'-O-methylation. Nucleic Acids Res 2021; 49:4066-4084. [PMID: 33721027 PMCID: PMC8053091 DOI: 10.1093/nar/gkab159] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 02/23/2021] [Accepted: 02/26/2021] [Indexed: 12/18/2022] Open
Abstract
RNA helicases play important roles in diverse aspects of RNA metabolism through their functions in remodelling ribonucleoprotein complexes (RNPs), such as pre-ribosomes. Here, we show that the DEAD box helicase Dbp3 is required for efficient processing of the U18 and U24 intron-encoded snoRNAs and 2′-O-methylation of various sites within the 25S ribosomal RNA (rRNA) sequence. Furthermore, numerous box C/D snoRNPs accumulate on pre-ribosomes in the absence of Dbp3. Many snoRNAs guiding Dbp3-dependent rRNA modifications have overlapping pre-rRNA basepairing sites and therefore form mutually exclusive interactions with pre-ribosomes. Analysis of the distribution of these snoRNAs between pre-ribosome-associated and ‘free’ pools demonstrated that many are almost exclusively associated with pre-ribosomal complexes. Our data suggest that retention of such snoRNPs on pre-ribosomes when Dbp3 is lacking may impede rRNA 2′-O-methylation by reducing the recycling efficiency of snoRNPs and by inhibiting snoRNP access to proximal target sites. The observation of substoichiometric rRNA modification at adjacent sites suggests that the snoRNPs guiding such modifications likely interact stochastically rather than hierarchically with their pre-rRNA target sites. Together, our data provide new insights into the dynamics of snoRNPs on pre-ribosomal complexes and the remodelling events occurring during the early stages of ribosome assembly.
Collapse
Affiliation(s)
- Gerald Ryan R Aquino
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, 3B Blegdamsvej, 2200N Copenhagen, Denmark
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Roman Martin
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Jimena Davila Gallesio
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Robert W van Nues
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Claudia Schneider
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Nicholas J Watkins
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 3B Blegdamsvej, 2200N Copenhagen, Denmark.,Genomics group, Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| |
Collapse
|
16
|
Ding B, Sepehrimanesh M. Nucleocytoplasmic Transport: Regulatory Mechanisms and the Implications in Neurodegeneration. Int J Mol Sci 2021; 22:4165. [PMID: 33920577 PMCID: PMC8072611 DOI: 10.3390/ijms22084165] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
Nucleocytoplasmic transport (NCT) across the nuclear envelope is precisely regulated in eukaryotic cells, and it plays critical roles in maintenance of cellular homeostasis. Accumulating evidence has demonstrated that dysregulations of NCT are implicated in aging and age-related neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer's disease (AD), and Huntington disease (HD). This is an emerging research field. The molecular mechanisms underlying impaired NCT and the pathogenesis leading to neurodegeneration are not clear. In this review, we comprehensively described the components of NCT machinery, including nuclear envelope (NE), nuclear pore complex (NPC), importins and exportins, RanGTPase and its regulators, and the regulatory mechanisms of nuclear transport of both protein and transcript cargos. Additionally, we discussed the possible molecular mechanisms of impaired NCT underlying aging and neurodegenerative diseases, such as ALS/FTD, HD, and AD.
Collapse
Affiliation(s)
- Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, 410 East Saint Mary Boulevard, Lafayette, LA 70503, USA;
| | | |
Collapse
|
17
|
Choudhury P, Kretschmer J, Hackert P, Bohnsack KE, Bohnsack MT. The DExD box ATPase DDX55 is recruited to domain IV of the 28S ribosomal RNA by its C-terminal region. RNA Biol 2020; 18:1124-1135. [PMID: 33048000 PMCID: PMC8244758 DOI: 10.1080/15476286.2020.1829366] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
RNA helicases contribute to diverse aspects of RNA metabolism through their functions in re-arranging RNA structures. Identification of the remodelling targets of RNA helicases is a critical step in elucidating their cellular functions. Here, we show that, in contrast to many other ribosome biogenesis factors, the DExD box ATPase DDX55 predominantly localizes to the nucleoplasm and we identify a nuclear localization signal within the C-terminal region of the protein. DDX55 associates with pre-ribosomal subunits in human cells and is required for maturation of large subunit pre-rRNAs. Interestingly, in vitro analyses show that DDX55 selectively associates with double-stranded RNA substrates, which also stimulate its ATPase activity, and our data suggest that the C-terminal region of DDX55 contributes to this substrate specificity. The C-terminal region of DDX55 is also necessary for recruitment of the helicase to pre-ribosomes and, using in vivo crosslinking, we reveal a binding site for DDX55 in helix H62 of the 28S ribosomal RNA. Taken together, these data highlight the importance of the C-terminal region of DDX55 in substrate specificity and recruitment, and identify domain IV as a potential remodelling target of DDX55 during LSU biogenesis.
Collapse
Affiliation(s)
- Priyanka Choudhury
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Jens Kretschmer
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Germany
| |
Collapse
|
18
|
Davila Gallesio J, Hackert P, Bohnsack KE, Bohnsack MT. Sgd1 is an MIF4G domain-containing cofactor of the RNA helicase Fal1 and associates with the 5' domain of the 18S rRNA sequence. RNA Biol 2020; 17:539-553. [PMID: 31994962 PMCID: PMC7237134 DOI: 10.1080/15476286.2020.1716540] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Assembly of eukaryotic ribosomal subunits is a complex and dynamic process involving the action of more than 200 trans-acting assembly factors. Although recent cryo-electron microscopy structures have provided information on architecture of several pre-ribosomal particles and the binding sites of many AFs, the RNA and protein interactions of many other AFs not captured in these snapshots still remain elusive. RNA helicases are key regulators of structural rearrangements within pre-ribosomal complexes and here we have analysed the eIF4A-like RNA helicase Fal1 and its putative cofactor Sgd1. Our data show that these proteins interact directly via the MIF4G domain of Sgd1 and that the MIF4G domain of Sgd1 stimulates the catalytic activity of Fal1 in vitro. The catalytic activity of Fal1, and the interaction between Fal1 and Sgd1, are required for efficient pre-rRNA processing at the A0, A1 and A2 sites. Furthermore, Sgd1 co-purifies the early small subunit biogenesis factors Lcp5 and Rok1, suggesting that the Fal1-Sgd1 complex likely functions within the SSU processome. In vivo crosslinking data reveal that Sgd1 binds to helix H12 of the 18S rRNA sequence and we further demonstrate that this interaction is formed by the C-terminal region of the protein, which is essential for its function in ribosome biogenesis.
Collapse
Affiliation(s)
- Jimena Davila Gallesio
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Germany
| |
Collapse
|
19
|
Liu H, Hu PW, Budhiraja S, Misra A, Couturier J, Lloyd RE, Lewis DE, Kimata JT, Rice AP. PACS1 is an HIV-1 cofactor that functions in Rev-mediated nuclear export of viral RNA. Virology 2020; 540:88-96. [PMID: 31759187 PMCID: PMC7335006 DOI: 10.1016/j.virol.2019.10.004] [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] [Received: 03/05/2019] [Revised: 10/09/2019] [Accepted: 10/15/2019] [Indexed: 10/25/2022]
Abstract
HIV-1 is dependent upon cellular proteins to mediate the many processes required for viral replication. One such protein, PACS1, functions to localize Furin to the trans-Golgi network where Furin cleaves HIV-1 gp160 Envelope into gp41 and gp120. We show here that PACS1 also shuttles between the nucleus and cytoplasm, associates with the viral Rev protein and its cofactor CRM1, and contributes to nuclear export of viral transcripts. PACS1 appears specific to the Rev-CRM1 pathway and not other retroviral RNA export pathways. Over-expression of PACS1 increases nuclear export of unspliced viral RNA and significantly increases p24 expression in HIV-1-infected Jurkat CD4+ T cells. SiRNA depletion and over-expression experiments suggest that PACS1 may promote trafficking of HIV-1 GagPol RNA to a pathway distinct from that of translation on polyribosomes.
Collapse
Affiliation(s)
- Hongbing Liu
- Department of Molecular Virology and Microbiology, USA
| | - Pei-Wen Hu
- Department of Molecular Virology and Microbiology, USA
| | | | - Anisha Misra
- Department of Molecular Virology and Microbiology, USA
| | - Jacob Couturier
- Department of Internal Medicine, University of Texas Health Science Center, Houston, TX, USA
| | | | - Dorothy E Lewis
- Department of Internal Medicine, University of Texas Health Science Center, Houston, TX, USA
| | | | - Andrew P Rice
- Department of Molecular Virology and Microbiology, USA; Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
20
|
Hock EM, Maniecka Z, Hruska-Plochan M, Reber S, Laferrière F, Sahadevan M K S, Ederle H, Gittings L, Pelkmans L, Dupuis L, Lashley T, Ruepp MD, Dormann D, Polymenidou M. Hypertonic Stress Causes Cytoplasmic Translocation of Neuronal, but Not Astrocytic, FUS due to Impaired Transportin Function. Cell Rep 2020; 24:987-1000.e7. [PMID: 30044993 DOI: 10.1016/j.celrep.2018.06.094] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 05/14/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
The primarily nuclear RNA-binding protein FUS (fused in sarcoma) forms pathological cytoplasmic inclusions in a subset of early-onset amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients. In response to cellular stress, FUS is recruited to cytoplasmic stress granules, which are hypothesized to act as precursors of pathological inclusions. We monitored the stress-induced nucleocytoplasmic shuttling of endogenous FUS in an ex vivo mouse CNS model and human neural networks. We found that hyperosmolar, but not oxidative, stress induced robust cytoplasmic translocation of neuronal FUS, with transient nuclear clearance and loss of function. Surprisingly, this reaction is independent of stress granule formation and the molecular pathways activated by hyperosmolarity. Instead, it represents a mechanism mediated by cytoplasmic redistribution of Transportin 1/2 and is potentiated by transcriptional inhibition. Importantly, astrocytes, which remain unaffected in ALS/FTD-FUS, are spared from this stress reaction that may signify the initial event in the development of FUS pathology.
Collapse
Affiliation(s)
- Eva-Maria Hock
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Zuzanna Maniecka
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Marian Hruska-Plochan
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Stefan Reber
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Florent Laferrière
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Sonu Sahadevan M K
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Helena Ederle
- BioMedical Center (BMC), Ludwig-Maximiians-University Munich, 82152 Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Lauren Gittings
- Queen Square Brain Bank for Neurological Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 1PJ, UK
| | - Lucas Pelkmans
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Luc Dupuis
- Faculty of Medicine, INSERM UMR-S1118 and Fédération de Médecine Translationnelle, Université de Strasbourg, Strasbourg, France
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 1PJ, UK
| | - Marc-David Ruepp
- UK Dementia Research Institute Centre at King's College London, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, 125 Coldharbour Lane, London SE5 9NU, UK
| | - Dorothee Dormann
- BioMedical Center (BMC), Ludwig-Maximiians-University Munich, 82152 Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Magdalini Polymenidou
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Life Science Zurich Graduate School, University of Zurich and ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
21
|
Reduction of mRNA export unmasks different tissue sensitivities to low mRNA levels during Caenorhabditis elegans development. PLoS Genet 2019; 15:e1008338. [PMID: 31525188 PMCID: PMC6762213 DOI: 10.1371/journal.pgen.1008338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 09/26/2019] [Accepted: 07/31/2019] [Indexed: 12/25/2022] Open
Abstract
Animal development requires the execution of specific transcriptional programs in different sets of cells to build tissues and functional organs. Transcripts are exported from the nucleus to the cytoplasm where they are translated into proteins that, ultimately, carry out the cellular functions. Here we show that in Caenorhabditis elegans, reduction of mRNA export strongly affects epithelial morphogenesis and germline proliferation while other tissues remain relatively unaffected. Epithelialization and gamete formation demand a large number of transcripts in the cytoplasm for the duration of these processes. In addition, our findings highlight the existence of a regulatory feedback mechanism that activates gene expression in response to low levels of cytoplasmic mRNA. We expand the genetic characterization of nuclear export factor NXF-1 to other members of the mRNA export pathway to model mRNA export and recycling of NXF-1 back to the nucleus. Our model explains how mutations in genes involved in general processes, such as mRNA export, may result in tissue-specific developmental phenotypes. The Central Dogma of Biology schematically highlights the transmission of genetic information stored in DNA, through RNA, to the formation of proteins. This general flow implicates RNA export from the nucleus to the cytoplasm and proper protein localization within the eukaryotic cell. Ultimately, proteins are the cell’s structural and catalytic functional units. As a result, cells differentiate into one cell type or another (such as epithelial, muscle, neuron…) and exhibit specific shape and functionality. Here we describe, in a C. elegans model, how mutations in genes involved in a general and ubiquitous mechanism, such as mRNA export, may result in tissue-specific developmental phenotypes that show up in processes that are highly demanding of cytoplasmic transcripts like epithelialization and gamete formation. A deep understanding of the mechanisms underlying the "connectors" shown in the Central Dogma of Biology is key both to unravel the general genetic control of an organism’s development and, at the same time, contribute to a better understanding of tissue-specific diseases.
Collapse
|
22
|
Giampetruzzi A, Danielson EW, Gumina V, Jeon M, Boopathy S, Brown RH, Ratti A, Landers JE, Fallini C. Modulation of actin polymerization affects nucleocytoplasmic transport in multiple forms of amyotrophic lateral sclerosis. Nat Commun 2019; 10:3827. [PMID: 31444357 PMCID: PMC6707192 DOI: 10.1038/s41467-019-11837-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 08/01/2019] [Indexed: 12/30/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of unknown etiology. Although defects in nucleocytoplasmic transport (NCT) may be central to the pathogenesis of ALS and other neurodegenerative diseases, the molecular mechanisms modulating the nuclear pore function are still largely unknown. Here we show that genetic and pharmacological modulation of actin polymerization disrupts nuclear pore integrity, nuclear import, and downstream pathways such as mRNA post-transcriptional regulation. Importantly, we demonstrate that modulation of actin homeostasis can rescue nuclear pore instability and dysfunction caused by mutant PFN1 as well as by C9ORF72 repeat expansion, the most common mutation in ALS patients. Collectively, our data link NCT defects to ALS-associated cellular pathology and propose the regulation of actin homeostasis as a novel therapeutic strategy for ALS and other neurodegenerative diseases.
Collapse
Affiliation(s)
- Anthony Giampetruzzi
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Eric W Danielson
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Valentina Gumina
- Istituto Auxologico Italiano, IRCCS, Department of Neurology - Stroke Unit and Laboratory of Neuroscience, Milan, Italy
| | - Maryangel Jeon
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Sivakumar Boopathy
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Antonia Ratti
- Istituto Auxologico Italiano, IRCCS, Department of Neurology - Stroke Unit and Laboratory of Neuroscience, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Claudia Fallini
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01605, USA.
| |
Collapse
|
23
|
Maurice F, Pérébaskine N, Thore S, Fribourg S. In vitro dimerization of human RIO2 kinase. RNA Biol 2019; 16:1633-1642. [PMID: 31390939 DOI: 10.1080/15476286.2019.1653679] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
RIO proteins form a conserved family of atypical protein kinases. RIO2 is a serine/threonine protein kinase/ATPase involved in pre-40S ribosomal maturation. Current crystal structures of archaeal and fungal Rio2 proteins report a monomeric form of the protein. Here, we describe three atomic structures of the human RIO2 kinase showing that it forms a homodimer in vitro. Upon self-association, each protomer ATP-binding pocket is partially remodelled and found in an apostate. The homodimerization is mediated by key residues previously shown to be responsible for ATP binding and catalysis. This unusual in vitro protein kinase dimer reveals an intricate mechanism where identical residues are involved in substrate binding and oligomeric state formation. We speculate that such an oligomeric state might be formed also in vivo and might function in maintaining the protein in an inactive state and could be employed during import.
Collapse
Affiliation(s)
| | | | - Stéphane Thore
- INSERM U1212, UMR CNRS 5320, Université de Bordeaux , Bordeaux , France
| | | |
Collapse
|
24
|
Bohnsack KE, Bohnsack MT. Uncovering the assembly pathway of human ribosomes and its emerging links to disease. EMBO J 2019; 38:e100278. [PMID: 31268599 PMCID: PMC6600647 DOI: 10.15252/embj.2018100278] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/18/2019] [Accepted: 04/26/2019] [Indexed: 12/12/2022] Open
Abstract
The essential cellular process of ribosome biogenesis is at the nexus of various signalling pathways that coordinate protein synthesis with cellular growth and proliferation. The fact that numerous diseases are caused by defects in ribosome assembly underscores the importance of obtaining a detailed understanding of this pathway. Studies in yeast have provided a wealth of information about the fundamental principles of ribosome assembly, and although many features are conserved throughout eukaryotes, the larger size of human (pre-)ribosomes, as well as the evolution of additional regulatory networks that can modulate ribosome assembly and function, have resulted in a more complex assembly pathway in humans. Notably, many ribosome biogenesis factors conserved from yeast appear to have subtly different or additional functions in humans. In addition, recent genome-wide, RNAi-based screens have identified a plethora of novel factors required for human ribosome biogenesis. In this review, we discuss key aspects of human ribosome production, highlighting differences to yeast, links to disease, as well as emerging concepts such as extra-ribosomal functions of ribosomal proteins and ribosome heterogeneity.
Collapse
Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular BiologyUniversity Medical Center GöttingenGöttingenGermany
| | - Markus T Bohnsack
- Department of Molecular BiologyUniversity Medical Center GöttingenGöttingenGermany
- Göttingen Center for Molecular BiosciencesGeorg‐August UniversityGöttingenGermany
| |
Collapse
|
25
|
Becker D, Hirsch AG, Bender L, Lingner T, Salinas G, Krebber H. Nuclear Pre-snRNA Export Is an Essential Quality Assurance Mechanism for Functional Spliceosomes. Cell Rep 2019; 27:3199-3214.e3. [PMID: 31189105 DOI: 10.1016/j.celrep.2019.05.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/03/2019] [Accepted: 05/09/2019] [Indexed: 02/05/2023] Open
Abstract
Removal of introns from pre-mRNAs is an essential step in eukaryotic gene expression, mediated by spliceosomes that contain snRNAs as key components. Although snRNAs are transcribed in the nucleus and function in the same compartment, all except U6 shuttle to the cytoplasm. Surprisingly, the physiological relevance for shuttling is unclear, in particular because the snRNAs in Saccharomyces cerevisiae were reported to remain nuclear. Here, we show that all yeast pre-snRNAs including U6 undergo a stepwise maturation process after nuclear export by Mex67 and Xpo1. Sm- and Lsm-ring attachment occurs in the cytoplasm and is important for the snRNA re-import, mediated by Cse1 and Mtr10. Finally, nuclear pre-snRNA cleavage and trimethylation of the 5'-cap finalizes shuttling. Importantly, preventing pre-snRNAs from being exported or processed results in faulty spliceosome assembly and subsequent genome-wide splicing defects. Thus, pre-snRNA export is obligatory for functional splicing and resembles an essential evolutionarily conserved quality assurance step.
Collapse
Affiliation(s)
- Daniel Becker
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Anna Greta Hirsch
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Lysann Bender
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany
| | - Thomas Lingner
- Transkriptomanalyselabor, Institut für Entwicklungsbiochemie, Georg-August Universität Göttingen, Göttingen, Germany
| | - Gabriela Salinas
- Transkriptomanalyselabor, Institut für Entwicklungsbiochemie, Georg-August Universität Göttingen, Göttingen, Germany
| | - Heike Krebber
- Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, Göttingen, Germany.
| |
Collapse
|
26
|
Inactivation of Cyclic AMP Response Element Transcription Caused by Constitutive p38 Activation Is Mediated by Hyperphosphorylation-Dependent CRTC2 Nucleocytoplasmic Transport. Mol Cell Biol 2019; 39:MCB.00554-18. [PMID: 30782776 DOI: 10.1128/mcb.00554-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/01/2019] [Indexed: 01/05/2023] Open
Abstract
The p38 signal transduction pathway can be activated transiently or constitutively, depending on the contexts in which the activation occurs. However, the biological consequence of constitutive activation of p38 is largely unknown. After screening 300 transcriptional cofactors, we identified CRTC2 as a downstream substrate of constitutively activated p38. Constitutive, rather than transient, activation of p38 led to hyperphosphorylation of CRTC2, resulting in CRTC2 cytosolic relocation and subsequent inactivation of cyclic AMP response element (CRE)-mediated transcription. Interestingly, the cytosolic translocation of CRTC2 depended on phosphorylation accumulation at multiple sites (≥11 phosphoserine/phosphothreonine residues) but not on specific sites. The hyperphosphorylation-driven nucleocytoplasmic transport of CRTC2 may not be a rare case of nuclear export of proteins, as we also observed that constitutively activated p38 promoted FOS nuclear export in a hyperphosphorylation-dependent manner. Collectively, our study uncovered a previously unknown mechanism of inactivation of selected transcription, which results from hyperphosphorylation-driven nucleocytoplasmic transport of cofactors or transcription factors mediated by constitutively active kinase.
Collapse
|
27
|
Frey S, Rees R, Schünemann J, Ng SC, Fünfgeld K, Huyton T, Görlich D. Surface Properties Determining Passage Rates of Proteins through Nuclear Pores. Cell 2019; 174:202-217.e9. [PMID: 29958108 DOI: 10.1016/j.cell.2018.05.045] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/18/2018] [Accepted: 05/21/2018] [Indexed: 10/28/2022]
Abstract
Nuclear pore complexes (NPCs) conduct nucleocytoplasmic transport through an FG domain-controlled barrier. We now explore how surface-features of a mobile species determine its NPC passage rate. Negative charges and lysines impede passage. Hydrophobic residues, certain polar residues (Cys, His), and, surprisingly, charged arginines have striking translocation-promoting effects. Favorable cation-π interactions between arginines and FG-phenylalanines may explain this apparent paradox. Application of these principles to redesign the surface of GFP resulted in variants that show a wide span of transit rates, ranging from 35-fold slower than wild-type to ∼500 times faster, with the latter outpacing even naturally occurring nuclear transport receptors (NTRs). The structure of a fast and particularly FG-specific GFPNTR variant illustrates how NTRs can expose multiple regions for binding hydrophobic FG motifs while evading non-specific aggregation. Finally, we document that even for NTR-mediated transport, the surface-properties of the "passively carried" cargo can strikingly affect the translocation rate.
Collapse
Affiliation(s)
- Steffen Frey
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Renate Rees
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Jürgen Schünemann
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Sheung Chun Ng
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Kevser Fünfgeld
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Trevor Huyton
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
| |
Collapse
|
28
|
Cornelison GL, Levy SA, Jenson T, Frost B. Tau-induced nuclear envelope invagination causes a toxic accumulation of mRNA in Drosophila. Aging Cell 2019; 18:e12847. [PMID: 30411463 PMCID: PMC6351838 DOI: 10.1111/acel.12847] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 11/30/2022] Open
Abstract
The nucleus is a spherical dual-membrane bound organelle that encapsulates genomic DNA. In eukaryotes, messenger RNAs (mRNA) are transcribed in the nucleus and transported through nuclear pores into the cytoplasm for translation into protein. In certain cell types and pathological conditions, nuclei harbor tubular invaginations of the nuclear envelope known as the "nucleoplasmic reticulum." Nucleoplasmic reticulum expansion has recently been established as a mediator of neurodegeneration in tauopathies, including Alzheimer's disease. While the presence of pore-lined, cytoplasm-filled, nuclear envelope invaginations has been proposed to facilitate the rapid export of RNAs from the nucleus to the cytoplasm, the functional significance of nuclear envelope invaginations in regard to RNA export in any disorder is currently unknown. Here, we report that polyadenylated RNAs accumulate within and adjacent to tau-induced nuclear envelope invaginations in a Drosophila model of tauopathy. Genetic or pharmacologic inhibition of RNA export machinery reduces accumulation of polyadenylated RNA within and adjacent to nuclear envelope invaginations and reduces tau-induced neuronal death. These data are the first to point toward a possible role for RNA export through nuclear envelope invaginations in the pathogenesis of a neurodegenerative disorder and suggest that nucleocytoplasmic transport machinery may serve as a possible novel class of therapeutic targets for the treatment of tauopathies.
Collapse
Affiliation(s)
- Garrett L. Cornelison
- Department of Cell Systems and Anatomy, Barshop Institute for Longevity and Aging Studies, Glenn Biggs Institute for Alzheimer’s and Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Simon A. Levy
- Department of Cell Systems and Anatomy, Barshop Institute for Longevity and Aging Studies, Glenn Biggs Institute for Alzheimer’s and Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Tyler Jenson
- Department of Cell Systems and Anatomy, Barshop Institute for Longevity and Aging Studies, Glenn Biggs Institute for Alzheimer’s and Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| | - Bess Frost
- Department of Cell Systems and Anatomy, Barshop Institute for Longevity and Aging Studies, Glenn Biggs Institute for Alzheimer’s and Neurodegenerative DiseasesUniversity of Texas Health San AntonioSan AntonioTexas
| |
Collapse
|
29
|
The path of pre-ribosomes through the nuclear pore complex revealed by electron tomography. Nat Commun 2019; 10:497. [PMID: 30700705 PMCID: PMC6353910 DOI: 10.1038/s41467-019-08342-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 12/17/2018] [Indexed: 01/24/2023] Open
Abstract
Determining the path of single ribonucleoprotein (RNP) particles through the 100 nm-wide nuclear pore complex (NPC) by fluorescence microscopy remains challenging due to resolution limitation and RNP labeling constraints. By using high-pressure freezing and electron tomography, here we captured snapshots of the translocation of native RNP particles through NPCs in yeast and analyzed their trajectory at nanometer-scale resolution. Morphological and functional analyses indicate that these particles mostly correspond to pre-ribosomes. They are detected in 5–6% of the NPCs, with no apparent bias for NPCs adjacent to the nucleolus. Their path closely follows the central axis of the NPC through the nuclear and inner rings, but diverges at the cytoplasmic ring, suggesting interactions with the cytoplasmic nucleoporins. By applying a probabilistic queueing model to our data, we estimated that the dwell time of pre-ribosomes in the yeast NPC is ~90 ms. These data reveal distinct steps of pre-ribosome translocation through the NPC. Large protein complexes and ribonucleoprotein particles (RNPs) such as pre-ribosomes are transported from the nucleus to the cytoplasm through the nuclear pore complex (NPC). Here the authors use ultrafast freezing and electron tomography to catch snapshots of native RNPs crossing the NPC and estimate their transit time using a probabilistic model.
Collapse
|
30
|
Clark DP, Pazdernik NJ, McGehee MR. Processing of RNA. Mol Biol 2019. [DOI: 10.1016/b978-0-12-813288-3.00012-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
31
|
Choudhury P, Hackert P, Memet I, Sloan KE, Bohnsack MT. The human RNA helicase DHX37 is required for release of the U3 snoRNP from pre-ribosomal particles. RNA Biol 2018; 16:54-68. [PMID: 30582406 PMCID: PMC6380342 DOI: 10.1080/15476286.2018.1556149] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Ribosome synthesis is an essential cellular process, and perturbation of human ribosome production is linked to cancer and genetic diseases termed ribosomopathies. During their assembly, pre-ribosomal particles undergo numerous structural rearrangements, which establish the architecture present in mature complexes and serve as key checkpoints, ensuring the fidelity of ribosome biogenesis. RNA helicases are essential mediators of such remodelling events and here, we demonstrate that the DEAH-box RNA helicase DHX37 is required for maturation of the small ribosomal subunit in human cells. Our data reveal that the presence of DHX37 in early pre-ribosomal particles is monitored by a quality control pathway and that failure to recruit DHX37 leads to pre-rRNA degradation. Using an in vivo crosslinking approach, we show that DHX37 binds directly to the U3 small nucleolar RNA (snoRNA) and demonstrate that the catalytic activity of the helicase is required for dissociation of the U3 snoRNA from pre-ribosomal complexes. This is an important event during ribosome assembly as it enables formation of the central pseudoknot structure of the small ribosomal subunit. We identify UTP14A as a direct interaction partner of DHX37 and our data suggest that UTP14A can act as a cofactor that stimulates the activity of the helicase in the context of U3 snoRNA release.
Collapse
Affiliation(s)
- Priyanka Choudhury
- a Department of Molecular Biology , University Medical Centre Göttingen , Göttingen , Germany
| | - Philipp Hackert
- a Department of Molecular Biology , University Medical Centre Göttingen , Göttingen , Germany
| | - Indira Memet
- a Department of Molecular Biology , University Medical Centre Göttingen , Göttingen , Germany
| | - Katherine E Sloan
- a Department of Molecular Biology , University Medical Centre Göttingen , Göttingen , Germany
| | - Markus T Bohnsack
- a Department of Molecular Biology , University Medical Centre Göttingen , Göttingen , Germany.,b Göttingen Center for Molecular Biosciences , Georg-August University , Göttingen , Germany
| |
Collapse
|
32
|
RNA helicases mediate structural transitions and compositional changes in pre-ribosomal complexes. Nat Commun 2018; 9:5383. [PMID: 30568249 PMCID: PMC6300602 DOI: 10.1038/s41467-018-07783-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 11/28/2018] [Indexed: 01/31/2023] Open
Abstract
Production of eukaryotic ribosomal subunits is a highly dynamic process; pre-ribosomes undergo numerous structural rearrangements that establish the architecture present in mature complexes and serve as key checkpoints, ensuring the fidelity of ribosome assembly. Using in vivo crosslinking, we here identify the pre-ribosomal binding sites of three RNA helicases. Our data support roles for Has1 in triggering release of the U14 snoRNP, a critical event during early 40S maturation, and in driving assembly of domain I of pre-60S complexes. Binding of Mak5 to domain II of pre-60S complexes promotes recruitment of the ribosomal protein Rpl10, which is necessary for subunit joining and ribosome function. Spb4 binds to a molecular hinge at the base of ES27 facilitating binding of the export factor Arx1, thereby promoting pre-60S export competence. Our data provide important insights into the driving forces behind key structural remodelling events during ribosomal subunit assembly.
Collapse
|
33
|
Ederle H, Funk C, Abou-Ajram C, Hutten S, Funk EBE, Kehlenbach RH, Bailer SM, Dormann D. Nuclear egress of TDP-43 and FUS occurs independently of Exportin-1/CRM1. Sci Rep 2018; 8:7084. [PMID: 29728564 PMCID: PMC5935713 DOI: 10.1038/s41598-018-25007-5] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 04/13/2018] [Indexed: 12/11/2022] Open
Abstract
TDP-43 and FUS are nuclear proteins with multiple functions in mRNA processing. They play key roles in ALS (amyotrophic lateral sclerosis) and FTD (frontotemporal dementia), where they are partially lost from the nucleus and aggregate in the cytoplasm of neurons and glial cells. Defects in nucleocytoplasmic transport contribute to this pathology, hence nuclear import of both proteins has been studied in detail. However, their nuclear export routes remain poorly characterized and it is unclear whether aberrant nuclear export contributes to TDP-43 or FUS pathology. Here we show that predicted nuclear export signals in TDP-43 and FUS are non-functional and that both proteins are exported independently of the export receptor CRM1/Exportin-1. Silencing of Exportin-5 or the mRNA export factor Aly/REF, as well as mutations that abrogate RNA-binding do not impair export of TDP-43 and FUS. However, artificially enlarging TDP-43 or FUS impairs their nuclear egress, suggesting that they could leave the nucleus by passive diffusion. Finally, we found that inhibition of transcription causes accelerated nuclear egress of TDP-43, suggesting that newly synthesized RNA retains TDP-43 in the nucleus, limiting its egress into the cytoplasm. Our findings implicate reduced nuclear retention as a possible factor contributing to mislocalization of TDP-43 in ALS/FTD.
Collapse
Affiliation(s)
- Helena Ederle
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
- Graduate School of Systemic Neurosciences (GSN), 82152, Planegg-Martinsried, Germany
| | - Christina Funk
- Institute for Interfacial Engineering and Plasma Technology IGVP, University of Stuttgart, 70569, Stuttgart, Germany
- Frauenhofer Institute for Interfacial Engineering and Biotechnology, 70569, Stuttgart, Germany
| | - Claudia Abou-Ajram
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Saskia Hutten
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany
| | - Eva B E Funk
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, 81377, Munich, Germany
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Susanne M Bailer
- Institute for Interfacial Engineering and Plasma Technology IGVP, University of Stuttgart, 70569, Stuttgart, Germany
- Frauenhofer Institute for Interfacial Engineering and Biotechnology, 70569, Stuttgart, Germany
| | - Dorothee Dormann
- BioMedical Center (BMC), Cell Biology, Ludwig-Maximilians-University Munich, 82152, Planegg-Martinsried, Germany.
- Graduate School of Systemic Neurosciences (GSN), 82152, Planegg-Martinsried, Germany.
- Munich Cluster for Systems Neurology (SyNergy), 81377, Munich, Germany.
| |
Collapse
|
34
|
Dickey TH, Pyle AM. The SMAD3 transcription factor binds complex RNA structures with high affinity. Nucleic Acids Res 2017; 45:11980-11988. [PMID: 29036649 PMCID: PMC5714123 DOI: 10.1093/nar/gkx846] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/19/2017] [Indexed: 01/12/2023] Open
Abstract
Several members of the SMAD family of transcription factors have been reported to bind RNA in addition to their canonical double-stranded DNA (dsDNA) ligand. RNA binding by SMAD has the potential to affect numerous cellular functions that involve RNA. However, the affinity and specificity of this RNA binding activity has not been well characterized, which limits the ability to validate and extrapolate functional implications of this activity. Here we perform quantitative binding experiments in vitro to determine the ligand requirements for RNA binding by SMAD3. We find that SMAD3 binds poorly to single- and double-stranded RNA, regardless of sequence. However, SMAD3 binds RNA with large internal loops or bulges with high apparent affinity. This apparent affinity matches that for its canonical dsDNA ligand, suggesting a biological role for RNA binding by SMAD3.
Collapse
Affiliation(s)
- Thayne H Dickey
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Anna M Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.,Department of Chemistry, Yale University, New Haven, CT 06511, USA
| |
Collapse
|
35
|
Memet I, Doebele C, Sloan KE, Bohnsack MT. The G-patch protein NF-κB-repressing factor mediates the recruitment of the exonuclease XRN2 and activation of the RNA helicase DHX15 in human ribosome biogenesis. Nucleic Acids Res 2017; 45:5359-5374. [PMID: 28115624 PMCID: PMC5435916 DOI: 10.1093/nar/gkx013] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/04/2017] [Indexed: 01/05/2023] Open
Abstract
In eukaryotes, the synthesis of ribosomal subunits, which involves the maturation of the ribosomal (r)RNAs and assembly of ribosomal proteins, requires the co-ordinated action of a plethora of ribosome biogenesis factors. Many of these cofactors remain to be characterized in human cells. Here, we demonstrate that the human G-patch protein NF-κB-repressing factor (NKRF) forms a pre-ribosomal subcomplex with the DEAH-box RNA helicase DHX15 and the 5΄-3΄ exonuclease XRN2. Using UV crosslinking and analysis of cDNA (CRAC), we reveal that NKRF binds to the transcribed spacer regions of the pre-rRNA transcript. Consistent with this, we find that depletion of NKRF, XRN2 or DHX15 impairs an early pre-rRNA cleavage step (A’). The catalytic activity of DHX15, which we demonstrate is stimulated by NKRF functioning as a cofactor, is required for efficient A’ cleavage, suggesting that a structural remodelling event may facilitate processing at this site. In addition, we show that depletion of NKRF or XRN2 also leads to the accumulation of excised pre-rRNA spacer fragments and that NKRF is essential for recruitment of the exonuclease to nucleolar pre-ribosomal complexes. Our findings therefore reveal a novel pre-ribosomal subcomplex that plays distinct roles in the processing of pre-rRNAs and the turnover of excised spacer fragments.
Collapse
Affiliation(s)
- Indira Memet
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Carmen Doebele
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Katherine E Sloan
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany.,Göttingen Centre for Molecular Biosciences, Georg-August-University, 37073 Göttingen, Germany
| |
Collapse
|
36
|
Rohilla KJ, Gagnon KT. RNA biology of disease-associated microsatellite repeat expansions. Acta Neuropathol Commun 2017; 5:63. [PMID: 28851463 PMCID: PMC5574247 DOI: 10.1186/s40478-017-0468-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/22/2017] [Indexed: 12/13/2022] Open
Abstract
Microsatellites, or simple tandem repeat sequences, occur naturally in the human genome and have important roles in genome evolution and function. However, the expansion of microsatellites is associated with over two dozen neurological diseases. A common denominator among the majority of these disorders is the expression of expanded tandem repeat-containing RNA, referred to as xtrRNA in this review, which can mediate molecular disease pathology in multiple ways. This review focuses on the potential impact that simple tandem repeat expansions can have on the biology and metabolism of RNA that contain them and underscores important gaps in understanding. Merging the molecular biology of repeat expansion disorders with the current understanding of RNA biology, including splicing, transcription, transport, turnover and translation, will help clarify mechanisms of disease and improve therapeutic development.
Collapse
|
37
|
Kressler D, Hurt E, Baßler J. A Puzzle of Life: Crafting Ribosomal Subunits. Trends Biochem Sci 2017; 42:640-654. [DOI: 10.1016/j.tibs.2017.05.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/16/2017] [Accepted: 05/05/2017] [Indexed: 01/24/2023]
|
38
|
Zhang Y, Tang C, Yu T, Zhang R, Zheng H, Yan W. MicroRNAs control mRNA fate by compartmentalization based on 3' UTR length in male germ cells. Genome Biol 2017; 18:105. [PMID: 28615029 PMCID: PMC5471846 DOI: 10.1186/s13059-017-1243-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 05/23/2017] [Indexed: 12/18/2022] Open
Abstract
Background Post-transcriptional regulation of gene expression can be achieved through the control of mRNA stability, cytoplasmic compartmentalization, 3′ UTR length and translational efficacy. Spermiogenesis, a process through which haploid male germ cells differentiate into spermatozoa, represents an ideal model for studying post-transcriptional regulation in vivo because it involves a large number of transcripts that are physically sequestered in ribonucleoprotein particles (RNPs) and thus subjected to delayed translation. To explore how small RNAs regulate mRNA fate, we conducted RNA-Seq analyses to determine not only the levels of both mRNAs and small noncoding RNAs, but also their cytoplasmic compartmentalization during spermiogenesis. Result Among all small noncoding RNAs studied, miRNAs displayed the most dynamic changes in both abundance and subcytoplasmic localization. mRNAs with shorter 3′ UTRs became increasingly enriched in RNPs from pachytene spermatocytes to round spermatids, and the enrichment of shorter 3′ UTR mRNAs in RNPs coincided with newly synthesized miRNAs that target these mRNAs at sites closer to the stop codon. In contrast, the translocation of longer 3′ UTR mRNAs from RNPs to polysomes correlated with the production of new miRNAs that target these mRNAs at sites distal to the stop codon. Conclusions miRNAs appear to control cytoplasmic compartmentalization of mRNAs based on 3′ UTR length. Our data suggest that transcripts with longer 3′ UTRs tend to contain distal miRNA binding sites and are thus targeted to polysomes for translation followed by degradation. In contrast, those with shorter 3′ UTRs only possess proximal miRNA binding sites, which, therefore, are targeted into RNPs for enrichment and delayed translation. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1243-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ying Zhang
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Center for Molecular Medicine, Room 207B, 1664 North Virginia Street, MS/0575, Reno, NV, 89557, USA
| | - Chong Tang
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Center for Molecular Medicine, Room 207B, 1664 North Virginia Street, MS/0575, Reno, NV, 89557, USA
| | - Tian Yu
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, MS575, Reno, NV, 89557, USA
| | - Ruirui Zhang
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Center for Molecular Medicine, Room 207B, 1664 North Virginia Street, MS/0575, Reno, NV, 89557, USA
| | - Huili Zheng
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Center for Molecular Medicine, Room 207B, 1664 North Virginia Street, MS/0575, Reno, NV, 89557, USA
| | - Wei Yan
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Center for Molecular Medicine, Room 207B, 1664 North Virginia Street, MS/0575, Reno, NV, 89557, USA. .,Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, MS575, Reno, NV, 89557, USA.
| |
Collapse
|
39
|
Ederle H, Dormann D. TDP-43 and FUS en route from the nucleus to the cytoplasm. FEBS Lett 2017; 591:1489-1507. [PMID: 28380257 DOI: 10.1002/1873-3468.12646] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/24/2017] [Accepted: 04/02/2017] [Indexed: 12/13/2022]
Abstract
Misfolded or mislocalized RNA-binding proteins (RBPs) and, consequently, altered mRNA processing, can cause neuronal dysfunction, eventually leading to neurodegeneration. Two prominent examples are the RBPs TAR DNA-binding protein of 43 kDa (TDP-43) and fused in sarcoma (FUS), which form pathological messenger ribonucleoprotein aggregates in patients suffering from amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two devastating neurodegenerative disorders. Here, we review the multiple functions of TDP-43 and FUS in mRNA processing, both in the nucleus and in the cytoplasm. We discuss how TDP-43 and FUS may exit the nucleus and how defects in both nuclear and cytosolic mRNA processing events, and possibly nuclear export defects, may contribute to neurodegeneration and ALS/FTD pathogenesis.
Collapse
Affiliation(s)
- Helena Ederle
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany.,Graduate School of Systemic Neurosciences (GSN), Planegg-Martinsried, Germany
| | - Dorothee Dormann
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, Planegg-Martinsried, Germany.,Graduate School of Systemic Neurosciences (GSN), Planegg-Martinsried, Germany.,Munich Cluster for Systems Neurology (SyNergy), Germany
| |
Collapse
|
40
|
Gudde AEEG, van Kessel IDG, André LM, Wieringa B, Wansink DG. Trinucleotide-repeat expanded and normal DMPK transcripts contain unusually long poly(A) tails despite differential nuclear residence. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:740-749. [PMID: 28435090 DOI: 10.1016/j.bbagrm.2017.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/26/2017] [Accepted: 04/14/2017] [Indexed: 12/29/2022]
Abstract
In yeast and higher eukaryotes nuclear retention of transcripts may serve in control over RNA decay, nucleocytoplasmic transport and premature cytoplasmic appearance of mRNAs. Hyperadenylation of RNA is known to be associated with nuclear retention, but the cause-consequence relationship between hyperadenylation and regulation of RNA nuclear export is still unclear. We compared polyadenylation status between normal and expanded DMPK transcripts in muscle cells and tissues derived from unaffected individuals and patients with myotonic dystrophy type 1 (DM1). DM1 is an autosomal dominant disorder caused by (CTG)n repeat expansion in the DMPK gene. DM1 etiology is characterized by an almost complete block of nuclear export of DMPK transcripts carrying a long (CUG)n repeat, including aberrant sequestration of RNA-binding proteins. We show here by use of cell fractionation, RNA size separation and analysis of poly(A) tail length that a considerable fraction of transcripts from the normal DMPK allele is also retained in the nucleus (~30%). They carry poly(A) tails with an unusually broad length distribution, ranging between a few dozen to >500 adenosine residues. Remarkably, expanded DMPK (CUG)n transcripts from the mutant allele, almost exclusively nuclear, carry equally long poly(A) tails. Our findings thus suggest that nuclear retention may be a common feature of regulation of DMPK RNA expression. The typical forced nuclear residence of expanded DMPK transcripts affects this regulation in tissues of DM1 patients, but not through hyperadenylation.
Collapse
Affiliation(s)
- Anke E E G Gudde
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands
| | - Ingeborg D G van Kessel
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands
| | - Laurène M André
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands
| | - Bé Wieringa
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands
| | - Derick G Wansink
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands.
| |
Collapse
|
41
|
Rai U, Najm F, Tartakoff AM. Nucleolar asymmetry and the importance of septin integrity upon cell cycle arrest. PLoS One 2017; 12:e0174306. [PMID: 28339487 PMCID: PMC5365125 DOI: 10.1371/journal.pone.0174306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 03/07/2017] [Indexed: 12/31/2022] Open
Abstract
Cell cycle arrest can be imposed by inactivating the anaphase promoting complex (APC). In S. cerevisiae this arrest has been reported to stabilize a metaphase-like intermediate in which the nuclear envelope spans the bud neck, while chromatin repeatedly translocates between the mother and bud domains. The present investigation was undertaken to learn how other features of nuclear organization are affected upon depletion of the APC activator, Cdc20. We observe that the spindle pole bodies and the spindle repeatedly translocate across the narrow orifice at the level of the neck. Nevertheless, we find that the nucleolus (organized around rDNA repeats on the long right arm of chromosome XII) remains in the mother domain, marking the polarity of the nucleus. Accordingly, chromosome XII is polarized: TelXIIR remains in the mother domain and its centromere is predominantly located in the bud domain. In order to learn why the nucleolus remains in the mother domain, we studied the impact of inhibiting rRNA synthesis in arrested cells. We observed that this fragments the nucleolus and that these fragments entered the bud domain. Taken together with earlier observations, the restriction of the nucleolus to the mother domain therefore can be attributed to its massive structure. We also observed that inactivation of septins allowed arrested cells to complete the cell cycle, that the alternative APC activator, Cdh1, was required for completion of the cell cycle and that induction of Cdh1 itself caused arrested cells to progress to the end of the cell cycle.
Collapse
Affiliation(s)
- Urvashi Rai
- Cell Biology Program/Department of Molecular and Microbiology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Fadi Najm
- Division of Medical Sciences, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alan M. Tartakoff
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
42
|
Rout MP, Obado SO, Schenkman S, Field MC. Specialising the parasite nucleus: Pores, lamins, chromatin, and diversity. PLoS Pathog 2017; 13:e1006170. [PMID: 28253370 PMCID: PMC5333908 DOI: 10.1371/journal.ppat.1006170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Michael P. Rout
- The Rockefeller University, New York, New York, United States of America
| | - Samson O. Obado
- The Rockefeller University, New York, New York, United States of America
| | | | - Mark C. Field
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| |
Collapse
|
43
|
Peña C, Schütz S, Fischer U, Chang Y, Panse VG. Prefabrication of a ribosomal protein subcomplex essential for eukaryotic ribosome formation. eLife 2016; 5. [PMID: 27929371 PMCID: PMC5148605 DOI: 10.7554/elife.21755] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/29/2016] [Indexed: 01/21/2023] Open
Abstract
Spatial clustering of ribosomal proteins (r-proteins) through tertiary interactions is a striking structural feature of the eukaryotic ribosome. However, the functional importance of these intricate inter-connections, and how they are established is currently unclear. Here, we reveal that a conserved ATPase, Fap7, organizes interactions between neighboring r-proteins uS11 and eS26 prior to their delivery to the earliest ribosome precursor, the 90S. In vitro, uS11 only when bound to Fap7 becomes competent to recruit eS26 through tertiary contacts found between these r-proteins on the mature ribosome. Subsequently, Fap7 ATPase activity unloads the uS11:eS26 subcomplex onto its rRNA binding site, and therefore ensures stoichiometric integration of these r-proteins into the 90S. Fap7-depletion in vivo renders uS11 susceptible to proteolysis, and precludes eS26 incorporation into the 90S. Thus, prefabrication of a native-like r-protein subcomplex drives efficient and accurate construction of the eukaryotic ribosome. DOI:http://dx.doi.org/10.7554/eLife.21755.001
Collapse
Affiliation(s)
- Cohue Peña
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Sabina Schütz
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Ute Fischer
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Yiming Chang
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Vikram G Panse
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| |
Collapse
|
44
|
Sloan KE, Warda AS, Sharma S, Entian KD, Lafontaine DLJ, Bohnsack MT. Tuning the ribosome: The influence of rRNA modification on eukaryotic ribosome biogenesis and function. RNA Biol 2016; 14:1138-1152. [PMID: 27911188 PMCID: PMC5699541 DOI: 10.1080/15476286.2016.1259781] [Citation(s) in RCA: 408] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
rRNAs are extensively modified during their transcription and subsequent maturation in the nucleolus, nucleus and cytoplasm. RNA modifications, which are installed either by snoRNA-guided or by stand-alone enzymes, generally stabilize the structure of the ribosome. However, they also cluster at functionally important sites of the ribosome, such as the peptidyltransferase center and the decoding site, where they facilitate efficient and accurate protein synthesis. The recent identification of sites of substoichiometric 2'-O-methylation and pseudouridylation has overturned the notion that all rRNA modifications are constitutively present on ribosomes, highlighting nucleotide modifications as an important source of ribosomal heterogeneity. While the mechanisms regulating partial modification and the functions of specialized ribosomes are largely unknown, changes in the rRNA modification pattern have been observed in response to environmental changes, during development, and in disease. This suggests that rRNA modifications may contribute to the translational control of gene expression.
Collapse
Affiliation(s)
- Katherine E Sloan
- a Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University , Göttingen , Germany
| | - Ahmed S Warda
- a Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University , Göttingen , Germany
| | - Sunny Sharma
- b RNA Molecular Biology and Center for Microscopy and Molecular Imaging, F.R.S./FNRS, Université Libre de Bruxelles , Charleroi-Gosselies , Belgium
| | - Karl-Dieter Entian
- c Institute for Molecular Biosciences, Goethe University , Frankfurt am Main , Germany
| | - Denis L J Lafontaine
- b RNA Molecular Biology and Center for Microscopy and Molecular Imaging, F.R.S./FNRS, Université Libre de Bruxelles , Charleroi-Gosselies , Belgium
| | - Markus T Bohnsack
- a Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University , Göttingen , Germany.,d Göttingen Centre for Molecular Biosciences, Georg-August-University , Göttingen , Germany
| |
Collapse
|
45
|
Abstract
INTRODUCTION A number of cyclin-dependent kinases (CDKs) mediate key steps in the HIV-1 replication cycle and therefore have potential to serve as therapeutic targets for HIV-1 infection, especially in HIV-1 cure strategies. Current HIV-1 cure strategies involve the development of small molecules that are able to activate HIV-1 from latent infection, thereby allowing the immune system to recognize and clear infected cells. Areas covered: The role of seven CDK family members in the HIV-1 replication cycle is reviewed, with a focus on CDK9, as the mechanism whereby the viral Tat protein utilizes CDK9 to enhance viral replication is known in considerable detail. Expert opinion: Given the essential roles of CDKs in cellular proliferation and gene expression, small molecules that inhibit CDKs are unlikely to be feasible therapeutics for HIV-1 infection. However, small molecules that activate CDK9 and other select CDKs such as CDK11 have potential to reactivate latent HIV-1 and contribute to a functional cure of infection.
Collapse
Affiliation(s)
- Andrew P Rice
- a Department of Molecular Virology and Microbiology , Baylor College of Medicine , Houston , TX USA
| |
Collapse
|
46
|
Aksu M, Trakhanov S, Görlich D. Structure of the exportin Xpo4 in complex with RanGTP and the hypusine-containing translation factor eIF5A. Nat Commun 2016; 7:11952. [PMID: 27306458 PMCID: PMC4912631 DOI: 10.1038/ncomms11952] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 05/16/2016] [Indexed: 12/28/2022] Open
Abstract
Xpo4 is a bidirectional nuclear transport receptor that mediates nuclear export of eIF5A and Smad3 as well as import of Sox2 and SRY. How Xpo4 recognizes such a variety of cargoes is as yet unknown. Here we present the crystal structure of the RanGTP·Xpo4·eIF5A export complex at 3.2 Å resolution. Xpo4 has a similar structure as CRM1, but the NES-binding site is occluded, and a new interaction site evolved that recognizes both globular domains of eIF5A. eIF5A contains hypusine, a unique amino acid with two positive charges, which is essential for cell viability and eIF5A function in translation. The hypusine docks into a deep, acidic pocket of Xpo4 and is thus a critical element of eIF5A's complex export signature. This further suggests that Xpo4 recognizes other cargoes differently, and illustrates how Xpo4 suppresses - in a chaperone-like manner - undesired interactions of eIF5A inside nuclei.
Collapse
Affiliation(s)
- Metin Aksu
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Sergei Trakhanov
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| |
Collapse
|
47
|
Görlich D, Kriwacki RW. Editorial Overview: Functional and Mechanistic Landscape of the Nuclear Pore Complex. J Mol Biol 2016; 428:1947-8. [PMID: 27059782 DOI: 10.1016/j.jmb.2016.03.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States; Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38105, United States.
| |
Collapse
|