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King MR, Ruff KM, Pappu RV. Emergent microenvironments of nucleoli. Nucleus 2024; 15:2319957. [PMID: 38443761 PMCID: PMC10936679 DOI: 10.1080/19491034.2024.2319957] [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: 09/04/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024] Open
Abstract
In higher eukaryotes, the nucleolus harbors at least three sub-phases that facilitate multiple functionalities including ribosome biogenesis. The three prominent coexisting sub-phases are the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). Here, we review recent efforts in profiling sub-phase compositions that shed light on the types of physicochemical properties that emerge from compositional biases and territorial organization of specific types of macromolecules. We highlight roles played by molecular grammars which refers to protein sequence features including the substrate binding domains, the sequence features of intrinsically disordered regions, and the multivalence of these distinct types of domains / regions. We introduce the concept of a barcode of emergent physicochemical properties of nucleoli. Although our knowledge of the full barcode remains incomplete, we hope that the concept prompts investigations into undiscovered emergent properties and engenders an appreciation for how and why unique microenvironments control biochemical reactions.
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Affiliation(s)
- Matthew R. King
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Kiersten M. Ruff
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
| | - Rohit V. Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, Campus, MO, USA
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2
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Rozza R, Janoš P, Magistrato A. Assessing the Binding Mode of a Splicing Modulator Stimulating Pre-mRNA Binding to the Plastic U2AF2 Splicing Factor. J Chem Inf Model 2023; 63:7508-7517. [PMID: 37967032 DOI: 10.1021/acs.jcim.3c01204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
RNA recognition motifs (RRMs) play a pivotal role in RNA metabolism and the regulation of gene expression. Owing to their plasticity and fuzziness, targeting RRM/RNA interfaces with small molecules is a daunting challenge for drug discovery campaigns. The U2AF2 splicing factor, which recognizes the polypyrimidine (polyPy) sequence of premature messenger (pre-m)RNA, exhibits a dynamic architecture consisting of two RRMs joined by a disordered linker. An inhibitor, NSC-194308, was shown to enhance the binding of pre-mRNA to U2AF2, selectively triggering cell death in leukemia cell lines containing spliceosome mutations. The NSC-194308 binding mode remains elusive; yet, unraveling its knowledge may offer intriguing insights for effectively targeting U2AF2 and other flexible protein/protein/RNA interfaces with small molecules. To infer plausible NSC-194308 binding poses to U2AF2, here, we applied and benchmarked the performance of static and dynamic docking approaches, elucidating the molecular basis of the NSC-194308-induced pre-mRNA stabilization on U2AF2. We demonstrate that introducing dynamic effects is mandatory to assess the binding mode of the inhibitors when they target plastic and modular architectures, such as those formed by interacting RRMs. The latter are widespread across RNA binding proteins; therefore, this mechanism may be broadly applicable to discover new therapeutics aimed at selectively modulating the RNA function by targeting protein/protein/RNA interfaces.
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Affiliation(s)
- Riccardo Rozza
- National Research Council of Italy (CNR)-Institute of Material Foundry (IOM) c/o International School for Advanced Studies (SISSA), Via Bonomea, 265, 34136 Trieste, Italy
| | - Pavel Janoš
- National Research Council of Italy (CNR)-Institute of Material Foundry (IOM) c/o International School for Advanced Studies (SISSA), Via Bonomea, 265, 34136 Trieste, Italy
| | - Alessandra Magistrato
- National Research Council of Italy (CNR)-Institute of Material Foundry (IOM) c/o International School for Advanced Studies (SISSA), Via Bonomea, 265, 34136 Trieste, Italy
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3
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Jiang T, Wang L, Tang L, Zeb A, Hou Y. Identification of two short peptide motifs from serine/arginine-rich protein ribonucleic acid recognition motif-1 domain acting as splicing regulators. PeerJ 2023; 11:e16103. [PMID: 37744237 PMCID: PMC10512959 DOI: 10.7717/peerj.16103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/25/2023] [Indexed: 09/26/2023] Open
Abstract
Background Serine/arginine-rich (SR) proteins regulate pre-mRNA splicing. However, structurally similar proteins often behave differently in splicing regulation and the underlying mechanisms are largely unknown. Here, using SMN1/2 minigenes we extensively analyzed four SR proteins, SRSF1/5/6/9. Methods In this study, the effects of these proteins on SMN1/2 exon 7 splicing when tethered at either intron 6 or 7 were evaluated using an MS2-tethering assay. Deletion analysis in four SR proteins and co-overexpression analysis were performed. Results Splicing outcomes varied among all four SR proteins, SRSF1 and SRSF5 function the same at the two sites, acting as repressor and stimulator, respectively; while SRSF6 and SRSF9 promote exon 7 inclusion at only one site. Further, the key domains of each SR proteins were investigated, which identified a potent inhibitory nonapeptide in the C-terminus of SRSF1/9 ribonucleic acid recognition motif-1 (RRM1) and a potent stimulatory heptapeptide at the N-terminus of SRSF5/6 RRM1. Conclusion The insight of the four SR proteins and their domains in affecting SMN gene splicing brings a new perspective on the modes of action of SR proteins; and the functional peptides obtained here offers new ideas for developing splice switching-related therapies.
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Affiliation(s)
- Tao Jiang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
- Department of Rehabilitation, Southwest Hospital, Third Military Medical University Army Medical University, Chongqing, China
| | - Li Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Liang Tang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Azhar Zeb
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
| | - Yanjun Hou
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, NanJing, China
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Thongchot S, Aksonnam K, Thuwajit P, Yenchitsomanus PT, Thuwajit C. Nucleolin‑based targeting strategies in cancer treatment: Focus on cancer immunotherapy (Review). Int J Mol Med 2023; 52:81. [PMID: 37477132 PMCID: PMC10555485 DOI: 10.3892/ijmm.2023.5284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/15/2023] [Indexed: 07/22/2023] Open
Abstract
The benefits of treating several types of cancers using immunotherapy have recently been established. The overexpression of nucleolin (NCL) in a number of types of cancer provides an attractive antigen target for the development of novel anticancer immunotherapeutic treatments. NCL is a multifunctional protein abundantly distributed in the nucleus, cytoplasm and cell membrane. It influences carcinogenesis, and the proliferation, survival and metastasis of cancer cells, leading to cancer progression. Additionally, the meta‑analysis of total and cytoplasmic NCL overexpression indicates a poor prognosis of patients with breast cancer. The AS1411 aptamers currently appear to have therapeutic action in the phase II clinical trial. The authors' research group has recently explored the anticancer function of NCL through the activation of T cells by dendritic cell‑based immunotherapy. The present review describes and discusses the mechanisms through which the multiple functions of NCL can participate in the progression of cancer. In addition, the studies that define the utility of NCL‑dependent anticancer therapies are summarized, with specific focus being paid to cancer immunotherapeutic approaches.
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Affiliation(s)
- Suyanee Thongchot
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
- Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Krittaya Aksonnam
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Peti Thuwajit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Pa-Thai Yenchitsomanus
- Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University
- Division of Molecular Medicine, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Chanitra Thuwajit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
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5
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Carico C, Placzek WJ. Reviewing PTBP1 Domain Modularity in the Pre-Genomic Era: A Foundation to Guide the Next Generation of Exploring PTBP1 Structure-Function Relationships. Int J Mol Sci 2023; 24:11218. [PMID: 37446395 DOI: 10.3390/ijms241311218] [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: 06/02/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/15/2023] Open
Abstract
Polypyrimidine tract binding protein 1 (PTBP1) is one of the most well-described RNA binding proteins, known initially for its role as a splicing repressor before later studies revealed its numerous roles in RNA maturation, stability, and translation. While PTBP1's various biological roles have been well-described, it remains unclear how its four RNA recognition motif (RRM) domains coordinate these functions. The early PTBP1 literature saw extensive effort placed in detailing structures of each of PTBP1's RRMs, as well as their individual RNA sequence and structure preferences. However, limitations in high-throughput and high-resolution genomic approaches (i.e., next-generation sequencing had not yet been developed) precluded the functional translation of these findings into a mechanistic understanding of each RRM's contribution to overall PTBP1 function. With the emergence of new technologies, it is now feasible to begin elucidating the individual contributions of each RRM to PTBP1 biological functions. Here, we review all the known literature describing the apo and RNA bound structures of each of PTBP1's RRMs, as well as the emerging literature describing the dependence of specific RNA processing events on individual RRM domains. Our goal is to provide a framework of the structure-function context upon which to facilitate the interpretation of future studies interrogating the dynamics of PTBP1 function.
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Affiliation(s)
- Christine Carico
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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6
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Azman MS, Alard EL, Dodel M, Capraro F, Faraway R, Dermit M, Fan W, Chakraborty A, Ule J, Mardakheh FK. An ERK1/2-driven RNA-binding switch in nucleolin drives ribosome biogenesis and pancreatic tumorigenesis downstream of RAS oncogene. EMBO J 2023; 42:e110902. [PMID: 37039106 PMCID: PMC10233377 DOI: 10.15252/embj.2022110902] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 02/14/2023] [Accepted: 03/12/2023] [Indexed: 04/12/2023] Open
Abstract
Oncogenic RAS signaling reprograms gene expression through both transcriptional and post-transcriptional mechanisms. While transcriptional regulation downstream of RAS is relatively well characterized, how RAS post-transcriptionally modulates gene expression to promote malignancy remains largely unclear. Using quantitative RNA interactome capture analysis, we here reveal that oncogenic RAS signaling reshapes the RNA-bound proteomic landscape of pancreatic cancer cells, with a network of nuclear proteins centered around nucleolin displaying enhanced RNA-binding activity. We show that nucleolin is phosphorylated downstream of RAS, which increases its binding to pre-ribosomal RNA (rRNA), boosts rRNA production, and promotes ribosome biogenesis. This nucleolin-dependent enhancement of ribosome biogenesis is crucial for RAS-induced pancreatic cancer cell proliferation and can be targeted therapeutically to inhibit tumor growth. Our results reveal that oncogenic RAS signaling drives ribosome biogenesis by regulating the RNA-binding activity of nucleolin and highlight a crucial role for this mechanism in RAS-mediated tumorigenesis.
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Affiliation(s)
- Muhammad S Azman
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Emilie L Alard
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Martin Dodel
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Federica Capraro
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Rupert Faraway
- The Francis Crick InstituteLondonUK
- Dementia Research InstituteKing's College LondonLondonUK
| | - Maria Dermit
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Wanling Fan
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Alina Chakraborty
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Jernej Ule
- The Francis Crick InstituteLondonUK
- Dementia Research InstituteKing's College LondonLondonUK
| | - Faraz K Mardakheh
- Centre for Cancer Cell and Molecular Biology, Barts Cancer InstituteQueen Mary University of LondonLondonUK
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7
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Kiliszek A, Rypniewski W, Błaszczyk L. Exploring structural determinants and the role of nucleolin in formation of the long-range interactions between untranslated regions of p53 mRNA. RNA (NEW YORK, N.Y.) 2023; 29:630-643. [PMID: 36653114 PMCID: PMC10158990 DOI: 10.1261/rna.079378.122] [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: 07/24/2022] [Accepted: 01/02/2023] [Indexed: 05/06/2023]
Abstract
p53 protein is a key regulator of cellular homeostasis by coordinating the framework of antiproliferative pathways as a response to various stress factors. Although the main mechanism of stress-dependent induction of p53 protein relies on post-translational modifications influencing its stability and activity, a growing amount of evidence suggests that complex regulation of p53 expression occurs also at the mRNA level. This study explores structural determinants of long-range RNA-RNA interactions in p53 mRNA, crucial for stress-dependent regulation of p53 protein translation. We demonstrate that the 8-nt bulge motif plays a key structural role in base-pairing of complementary sequences from the 5' and 3' untranslated regions of p53 mRNA. We also show that one of the p53 translation regulators, nucleolin, displays an RNA chaperone activity and facilitates the association of sequences involved in the formation of long-range interactions in p53 mRNA. Nucleolin promotes base-pairing of complementary sequences through the bulge motif, because mutations of this region reduce or inhibit pairing while compensatory mutations restore this interaction. Mutational analysis of nucleolin reveals that all four RNA recognition motifs are indispensable for optimal RNA chaperone activity of nucleolin. These observations help to decipher the unique mechanism of p53 protein translation regulation pointing to bulge motif and nucleolin as the critical factors during intramolecular RNA-RNA recognition in p53 mRNA.
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Affiliation(s)
- Agnieszka Kiliszek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznań, Poland
| | - Wojciech Rypniewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznań, Poland
| | - Leszek Błaszczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznań, Poland
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8
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Niu J, Meng F, Hao Q, Zong C, Fu J, Xue H, Tian M, Yu X. Ratiometric and Discriminative Visualization of Autophagy and Apoptosis with a Single Fluorescent Probe Based on the Aggregation/Monomer Principle. Anal Chem 2022; 94:17885-17894. [PMID: 36516436 DOI: 10.1021/acs.analchem.2c03815] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Autophagy and apoptosis play a central role in maintaining homeostasis in mammals. Therefore, discriminative visualization of the two cellular processes is an important and challenging task. However, fluorescent probes enabling ratiometric visualization of both autophagy and apoptosis with different sets of fluorescence signals have not been developed yet. In this work, we constructed a versatile single fluorescent probe (NKLR) based on the aggregation/monomer principle for the ratiometric and discriminative visualization of autophagy and apoptosis. NKLR can simultaneously perform two-color imaging of RNA (deep red channel) and lysosomes (yellow channel) in aggregation and monomer states, respectively. During autophagy, NKLR migrated from cytoplasmic RNA and nuclear RNA to lysosomes, showing enhanced yellow emission and sharply decreased deep red fluorescence. Moreover, this migration process was reversible upon the recovery of autophagy. Comparatively, during apoptosis, NKLR immigrated from lysosomes to RNA, and the yellow emission decreased and even disappeared, while the fluorescence of the deep red channel slightly increased. Overall, autophagy and apoptosis could be discriminatively visualized via the fluorescence intensity ratios of the two channels. Meanwhile, the cells in three different states (healthy, autophagic, apoptotic) could be distinguished by three point-to-point fluorescence images via the localization and emission color of NKLR. Therefore, the probe NKLR can serve as a desirable molecular tool to reveal the in-depth relation between autophagy and apoptosis and facilitate the study on the two cellular processes.
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Affiliation(s)
- Jie Niu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Fangfang Meng
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Qiuhua Hao
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Chong Zong
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Jinyu Fu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Haiyan Xue
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong 250022, P. R. China
| | - Minggang Tian
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong 250022, P. R. China
| | - Xiaoqiang Yu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, P. R. China
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9
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An Y, Chen ZS, Chan H, Ngo J. Molecular insights into the interaction of CAG trinucleotide RNA repeats with nucleolin and its implication in polyglutamine diseases. Nucleic Acids Res 2022; 50:7655-7668. [PMID: 35776134 PMCID: PMC9303306 DOI: 10.1093/nar/gkac532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/08/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Polyglutamine (polyQ) diseases are a type of inherited neurodegenerative disorders caused by cytosine-adenine-guanine (CAG) trinucleotide expansion within the coding region of the disease-associated genes. We previously demonstrated that a pathogenic interaction between expanded CAG RNA and the nucleolin (NCL) protein triggers the nucleolar stress and neuronal cell death in polyQ diseases. However, mechanisms behind the molecular interaction remain unknown. Here, we report a 1.45 Å crystal structure of the r(CAG)5 oligo that comprises a full A'-form helical turn with widened grooves. Based on this structure, we simulated a model of r(CAG)5 RNA complexed with the RNA recognition motif 2 (RRM2) of NCL and identified NCL residues that are critical for its binding to CAG RNA. Combined with in vitro and in vivo site-directed mutagenesis studies, our model reveals that CAG RNA binds to NCL sites that are not important for other cellular functions like gene expression and rRNA synthesis regulation, indicating that toxic CAG RNA interferes with NCL functions by sequestering it. Accordingly, an NCL mutant that is aberrant in CAG RNA-binding could rescue RNA-induced cytotoxicity effectively. Taken together, our study provides new molecular insights into the pathogenic mechanism of polyQ diseases mediated by NCL-CAG RNA interaction.
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Affiliation(s)
- Ying An
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhefan S Chen
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Center for Novel Biomaterials, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
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10
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Wang D, Hou L, Zhu N, Yang X, Zhou J, Cui Y, Guo J, Feng X, Liu J. Interaction of Nucleolin with the Fusion Protein of Avian Metapneumovirus Subgroup C Contributes to Viral Replication. Viruses 2022; 14:v14071402. [PMID: 35891383 PMCID: PMC9317408 DOI: 10.3390/v14071402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
Avian metapneumovirus subgroup C (aMPV/C) is highly pathogenic to various avian species with acute respiratory tract clinicopathology and/or drops in egg production. Nucleolin (NCL), an important nucleolar protein, has been shown to regulate multiple viral replication and serve as a functional receptor for viral entry and internalization. Whether NCL is involved in aMPV/C pathogenesis is not known. In this study, we found that aMPV/C infection altered the subcellular localization of NCL in cultured cells. siRNA-targeted NCL resulted in a remarkable decline in aMPV/C replication in Vero cells. DF-1 cells showed a similar response after CRISPR/Cas9-mediated knock out of NCL during aMPV/C infection. Conversely, NCL overexpression significantly increased aMPV/C replication. Pretreatment with AS1411-a aptamer, a guanine (G)-rich oligonucleotide that forms four-stranded structures and competitively binding to NCL, decreased aMPV/C replication and viral titers in cultured cells. Additionally, we found that the aMPV/C fusion (F) protein specifically interacts with NCL through its central domain and that AS1411 disrupts this interaction, thus inhibiting viral replication. Taken together, these results reveal that the aMPV/C F protein interacts with NCL, which is employed by aMPV/C for efficient replication, thereby highlighting the strategic potential for control and therapy of aMPV/C infection.
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Affiliation(s)
- Dedong Wang
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Lei Hou
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Ning Zhu
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xiaoyu Yang
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jianwei Zhou
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Yongqiu Cui
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jinshuo Guo
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xufei Feng
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jue Liu
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Correspondence:
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Masoumzadeh E, Grozdanov PN, Jetly A, MacDonald CC, Latham MP. Electrostatic Interactions between CSTF2 and pre-mRNA Drive Cleavage and Polyadenylation. Biophys J 2022; 121:607-619. [PMID: 35090899 PMCID: PMC8873925 DOI: 10.1016/j.bpj.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/20/2021] [Accepted: 01/07/2022] [Indexed: 11/25/2022] Open
Abstract
Nascent pre-mRNA 3'-end cleavage and polyadenylation (C/P) involves numerous proteins that recognize multiple RNA elements. Human CSTF2 binds to a downstream U- or G/U-rich sequence through its RNA recognition motif (RRM) regulating C/P. We previously reported the only known disease-related CSTF2 RRM mutant (CSTF2D50A) and showed that it changed the on-rate of RNA binding, leading to alternative polyadenylation in brains of mice carrying the same mutation. In this study, we further investigated the role of electrostatic interactions in the thermodynamics and kinetics of RNA binding for the CSTF2 RRM and the downstream consequences for regulation of C/P. By combining mutagenesis with NMR spectroscopy and biophysical assays, we confirmed that electrostatic attraction is the dominant factor in RRM binding to a naturally occurring U-rich RNA sequence. Moreover, we demonstrate that RNA binding is accompanied by an enthalpy-entropy compensation mechanism that is supported by changes in pico-to-nanosecond timescale RRM protein dynamics. We suggest that the dynamic binding of the RRM to U-rich RNA supports the diversity of sequences it encounters in the nucleus. Lastly, in vivo C/P assays demonstrate a competition between fast, high affinity RNA binding and efficient, correct C/P. These results highlight the importance of the surface charge of the RRM in RNA binding and the balance between nascent mRNA binding and C/P in vivo.
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12
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Soubise B, Jiang Y, Douet-Guilbert N, Troadec MB. RBM22, a Key Player of Pre-mRNA Splicing and Gene Expression Regulation, Is Altered in Cancer. Cancers (Basel) 2022; 14:cancers14030643. [PMID: 35158909 PMCID: PMC8833553 DOI: 10.3390/cancers14030643] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/19/2022] [Accepted: 01/22/2022] [Indexed: 01/05/2023] Open
Abstract
RNA-Binding Proteins (RBP) are very diverse and cover a large number of functions in the cells. This review focuses on RBM22, a gene encoding an RBP and belonging to the RNA-Binding Motif (RBM) family of genes. RBM22 presents a Zinc Finger like and a Zinc Finger domain, an RNA-Recognition Motif (RRM), and a Proline-Rich domain with a general structure suggesting a fusion of two yeast genes during evolution: Cwc2 and Ecm2. RBM22 is mainly involved in pre-mRNA splicing, playing the essential role of maintaining the conformation of the catalytic core of the spliceosome and acting as a bridge between the catalytic core and other essential protein components of the spliceosome. RBM22 is also involved in gene regulation, and is able to bind DNA, acting as a bona fide transcription factor on a large number of target genes. Undoubtedly due to its wide scope in the regulation of gene expression, RBM22 has been associated with several pathologies and, notably, with the aggressiveness of cancer cells and with the phenotype of a myelodysplastic syndrome. Mutations, enforced expression level, and haploinsufficiency of RBM22 gene are observed in those diseases. RBM22 could represent a potential therapeutic target in specific diseases, and, notably, in cancer.
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Affiliation(s)
- Benoît Soubise
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (B.S.); (Y.J.); (N.D.-G.)
| | - Yan Jiang
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (B.S.); (Y.J.); (N.D.-G.)
- Department of Hematology, The First Hospital of Jilin University, Changchun 130021, China
| | - Nathalie Douet-Guilbert
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (B.S.); (Y.J.); (N.D.-G.)
- CHRU Brest, Service de Génétique, Laboratoire de Génétique Chromosomique, F-29200 Brest, France
| | - Marie-Bérengère Troadec
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (B.S.); (Y.J.); (N.D.-G.)
- CHRU Brest, Service de Génétique, Laboratoire de Génétique Chromosomique, F-29200 Brest, France
- Correspondence: ; Tel.: +33-2-98-01-64-55
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13
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Nikulin AD. Characteristic Features of Protein Interaction with Single- and Double-Stranded RNA. BIOCHEMISTRY (MOSCOW) 2021; 86:1025-1040. [PMID: 34488578 DOI: 10.1134/s0006297921080125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The review discusses differences between the specific protein interactions with single- and double-stranded RNA molecules using the data on the structure of RNA-protein complexes. Proteins interacting with the single-stranded RNAs form contacts with RNA bases, which ensures recognition of specific nucleotide sequences. Formation of such contacts with the double-stranded RNAs is hindered, so that the proteins recognize unique conformations of the RNA spatial structure and interact mainly with the RNA sugar-phosphate backbone.
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Affiliation(s)
- Alexey D Nikulin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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14
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González‐Arzola K, Guerra‐Castellano A, Rivero‐Rodríguez F, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MA. Mitochondrial cytochrome c shot towards histone chaperone condensates in the nucleus. FEBS Open Bio 2021; 11:2418-2440. [PMID: 33938164 PMCID: PMC8409293 DOI: 10.1002/2211-5463.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
Despite mitochondria being key for the control of cell homeostasis and fate, their role in DNA damage response is usually just regarded as an apoptotic trigger. However, growing evidence points to mitochondrial factors modulating nuclear functions. Remarkably, after DNA damage, cytochrome c (Cc) interacts in the cell nucleus with a variety of well-known histone chaperones, whose activity is competitively inhibited by the haem protein. As nuclear Cc inhibits the nucleosome assembly/disassembly activity of histone chaperones, it might indeed affect chromatin dynamics and histone deposition on DNA. Several histone chaperones actually interact with Cc Lys residues through their acidic regions, which are also involved in heterotypic interactions leading to liquid-liquid phase transitions responsible for the assembly of nuclear condensates, including heterochromatin. This relies on dynamic histone-DNA interactions that can be modulated by acetylation of specific histone Lys residues. Thus, Cc may have a major regulatory role in DNA repair by fine-tuning nucleosome assembly activity and likely nuclear condensate formation.
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Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Francisco Rivero‐Rodríguez
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
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15
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Yu AT, Berasain C, Bhatia S, Rivera K, Liu B, Rigo F, Pappin DJ, Spector DL. PHAROH lncRNA regulates Myc translation in hepatocellular carcinoma via sequestering TIAR. eLife 2021; 10:68263. [PMID: 34002693 PMCID: PMC8163507 DOI: 10.7554/elife.68263] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/02/2021] [Indexed: 12/26/2022] Open
Abstract
Hepatocellular carcinoma, the most common type of liver malignancy, is one of the most lethal forms of cancer. We identified a long non-coding RNA, Gm19705, that is overexpressed in hepatocellular carcinoma and mouse embryonic stem cells. We named this RNA Pluripotency and Hepatocyte Associated RNA Overexpressed in HCC, or PHAROH. Depletion of PHAROH impacts cell proliferation and migration, which can be rescued by ectopic expression of PHAROH. RNA-seq analysis of PHAROH knockouts revealed that a large number of genes with decreased expression contain a Myc motif in their promoter. MYC is decreased in knockout cells at the protein level, but not the mRNA level. RNA-antisense pulldown identified nucleolysin TIAR, a translational repressor, to bind to a 71-nt hairpin within PHAROH, sequestration of which increases MYC translation. In summary, our data suggest that PHAROH regulates MYC translation by sequestering TIAR and as such represents a potentially exciting diagnostic or therapeutic target in hepatocellular carcinoma.
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Affiliation(s)
- Allen T Yu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States.,Genetics Program, Stony Brook University, Stony Brook, United States
| | - Carmen Berasain
- Hepatology Program, Cima, University of Navarra, Pamplona, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid, Spain
| | - Sonam Bhatia
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
| | - Keith Rivera
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
| | - Bodu Liu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, United States
| | - Darryl J Pappin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
| | - David L Spector
- Cold Spring Harbor Laboratory, Cold Spring Harbor, United States.,Genetics Program, Stony Brook University, Stony Brook, United States
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16
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Matsumoto S, Sugimoto N. New Insights into the Functions of Nucleic Acids Controlled by Cellular Microenvironments. Top Curr Chem (Cham) 2021; 379:17. [PMID: 33782792 DOI: 10.1007/s41061-021-00329-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/11/2021] [Indexed: 12/11/2022]
Abstract
The right-handed double-helical B-form structure (B-form duplex) has been widely recognized as the canonical structure of nucleic acids since it was first proposed by James Watson and Francis Crick in 1953. This B-form duplex model has a monochronic and static structure and codes genetic information within a sequence. Interestingly, DNA and RNA can form various non-canonical structures, such as hairpin loops, left-handed helices, triplexes, tetraplexes of G-quadruplex and i-motif, and branched junctions, in addition to the canonical structure. The formation of non-canonical structures depends not only on sequence but also on the surrounding environment. Importantly, these non-canonical structures may exhibit a wide variety of biological roles by changing their structures and stabilities in response to the surrounding environments, which undergo vast changes at specific locations and at specific times in cells. Here, we review recent progress regarding the interesting behaviors and functions of nucleic acids controlled by molecularly crowded cellular conditions. New insights gained from recent studies suggest that nucleic acids not only code genetic information in sequences but also have unknown functions regarding their structures and stabilities through drastic structural changes in cellular environments.
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Affiliation(s)
- Saki Matsumoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan. .,Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan.
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17
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Chen X, Yang Z, Wang W, Qian K, Liu M, Wang J, Wang M. Structural basis for RNA recognition by the N-terminal tandem RRM domains of human RBM45. Nucleic Acids Res 2021; 49:2946-2958. [PMID: 33577684 PMCID: PMC7968997 DOI: 10.1093/nar/gkab075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/16/2021] [Accepted: 01/28/2021] [Indexed: 12/20/2022] Open
Abstract
RBM45 is an RNA-binding protein involved in neural development, whose aggregation is associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). However, the mechanisms of RNA-binding and aggregation of RBM45 remain unelucidated. Here, we report the crystal structure of the N-terminal tandem RRM domains of human RBM45 in complex with single-stranded DNA (ssDNA). Our structural and biochemical results revealed that both the RRM1 and RRM2 of RBM45 recognized the GAC sequence of RNA/ssDNA. Two aromatic residues and an arginine residue in each RRM were critical for RNA-binding, and the interdomain linker was also involved in RNA-binding. Two RRMs formed a pair of antiparallel RNA-binding sites, indicating that the N-terminal tandem RRM domains of RBM45 bound separate GAC motifs in one RNA strand or GAC motifs in different RNA strands. Our findings will be helpful in the identification of physiologic targets of RBM45 and provide evidence for understanding the physiologic and pathologic functions of RBM45.
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Affiliation(s)
- Xiaolei Chen
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Zhongmei Yang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Wenfeng Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Kaiyue Qian
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Mingjie Liu
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Junchao Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
| | - Mingzhu Wang
- Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China.,Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, 111 Jiulong Road, Hefei 230601, Anhui, China
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18
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Okuwaki M, Saotome-Nakamura A, Yoshimura M, Saito S, Hirawake-Mogi H, Sekiya T, Nagata K. RNA-recognition motifs and glycine and arginine-rich region cooperatively regulate the nucleolar localization of nucleolin. J Biochem 2021; 169:87-100. [PMID: 32785674 DOI: 10.1093/jb/mvaa095] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/03/2020] [Indexed: 01/11/2023] Open
Abstract
Nucleolin (NCL) is a nucleolar protein i.e. involved in the regulation of the nucleolar structure and functions, and consists of three distinct regions: the N-terminal region; the middle region, which contains four RNA-recognition motifs (RRMs); and the C-terminal glycine- and arginine-rich (GAR) region. The primary function of the RRMs and GAR is thought to be specific RNA binding. However, it is not well understood how these RNA-binding regions of NCL separately or cooperatively regulate its nucleolar localization and functions. To address this issue, we constructed mutant proteins carrying point mutations at the four RRMs individually or deletion of the C-terminal GAR region. We found that the GAR deletion and the mutations in the fourth RRM (RRM4) decreased the nucleolar localization of NCL. Biochemical analyses showed that NCL interacted directly with ribosomal RNAs (rRNAs) and G-rich oligonucleotides, and that this interaction was decreased by mutations at RRM1 and RRM4 and GAR deletion. Although GAR deletion decreased the rRNA-binding activity of NCL, the mutant was efficiently coprecipitated with rRNAs and nucleolar proteins from cell extracts. These contradictory results suggest that NCL stably localizes to the nucleoli via the interactions with rRNAs and nucleolar proteins via GAR, RRM1 and RRM4.
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Affiliation(s)
- Mitsuru Okuwaki
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Ai Saotome-Nakamura
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Masashi Yoshimura
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Shoko Saito
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Hiroko Hirawake-Mogi
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takeshi Sekiya
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Kyosuke Nagata
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
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19
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Dong HJ, Zhang R, Kuang Y, Wang XJ. Selective regulation in ribosome biogenesis and protein production for efficient viral translation. Arch Microbiol 2020; 203:1021-1032. [PMID: 33124672 PMCID: PMC7594972 DOI: 10.1007/s00203-020-02094-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/18/2020] [Accepted: 10/13/2020] [Indexed: 11/25/2022]
Abstract
As intracellular parasites, viruses depend heavily on host cell structures and their functions to complete their life cycle and produce new viral particles. Viruses utilize or modulate cellular translational machinery to achieve efficient replication; the role of ribosome biogenesis and protein synthesis in viral replication particularly highlights the importance of the ribosome quantity and/or quality in controlling viral protein synthesis. Recently reported studies have demonstrated that ribosome biogenesis factors (RBFs) and ribosomal proteins (RPs) act as multifaceted regulators in selective translation of viral transcripts. Here we summarize the recent literature on RBFs and RPs and their association with subcellular redistribution, post-translational modification, enzyme catalysis, and direct interaction with viral proteins. The advances described in this literature establish a rationale for targeting ribosome production and function in the design of the next generation of antiviral agents.
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Affiliation(s)
- Hui-Jun Dong
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Rui Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
| | - Yu Kuang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
| | - Xiao-Jia Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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20
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Phase Separation of Epstein-Barr Virus EBNA2 and Its Coactivator EBNALP Controls Gene Expression. J Virol 2020; 94:JVI.01771-19. [PMID: 31941785 DOI: 10.1128/jvi.01771-19] [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: 10/15/2019] [Accepted: 01/03/2020] [Indexed: 12/19/2022] Open
Abstract
Biological macromolecule condensates formed by liquid-liquid phase separation (LLPS) have been discovered in recent years to be prevalent in biology. These condensates are involved in diverse processes, including the regulation of gene expression. LLPS of proteins have been found in animal, plant, and bacterial species but have scarcely been identified in viral proteins. Here, we discovered that Epstein-Barr virus (EBV) EBNA2 and EBNALP form nuclear puncta that exhibit properties of liquid-like condensates (or droplets), which are enriched in superenhancers of MYC and Runx3. EBNA2 and EBNALP are transcription factors, and the expression of their target genes is suppressed by chemicals that perturb LLPS. Intrinsically disordered regions (IDRs) of EBNA2 and EBNALP can form phase-separated droplets, and specific proline residues of EBNA2 and EBNALP contribute to droplet formation. These findings offer a foundation for understanding the mechanism by which LLPS, previously determined to be related to the organization of P bodies, membraneless organelles, nucleolus homeostasis, and cell signaling, plays a key role in EBV-host interactions and is involved in regulating host gene expression. This work suggests a novel anti-EBV strategy where developing appropriate drugs of interfering LLPS can be used to destroy the function of the EBV's transcription factors.IMPORTANCE Protein condensates can be assembled via liquid-liquid phase separation (LLPS), a process involving the concentration of molecules in a confined liquid-like compartment. LLPS allows for the compartmentalization and sequestration of materials and can be harnessed as a sensitive strategy for responding to small changes in the environment. This study identified the Epstein-Barr virus (EBV) proteins EBNA2 and EBNALP, which mediate virus and cellular gene transcription, as transcription factors that can form liquid-like condensates at superenhancer sites of MYC and Runx3. This study discovered the first identified LLPS of EBV proteins and emphasized the importance of LLPS in controlling host gene expression.
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21
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Monitoring mitochondrial membrane potential by FRET: Development of fluorescent probes enabling ΔΨm-Dependent subcellular migration. Anal Chim Acta 2020; 1097:196-203. [DOI: 10.1016/j.aca.2019.11.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/20/2019] [Accepted: 11/04/2019] [Indexed: 01/01/2023]
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22
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Ankush Jagtap PK, Müller M, Masiewicz P, von Bülow S, Hollmann NM, Chen PC, Simon B, Thomae AW, Becker PB, Hennig J. Structure, dynamics and roX2-lncRNA binding of tandem double-stranded RNA binding domains dsRBD1,2 of Drosophila helicase Maleless. Nucleic Acids Res 2019; 47:4319-4333. [PMID: 30805612 PMCID: PMC6486548 DOI: 10.1093/nar/gkz125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/31/2019] [Accepted: 02/22/2019] [Indexed: 12/19/2022] Open
Abstract
Maleless (MLE) is an evolutionary conserved member of the DExH family of helicases in Drosophila. Besides its function in RNA editing and presumably siRNA processing, MLE is best known for its role in remodelling non-coding roX RNA in the context of X chromosome dosage compensation in male flies. MLE and its human orthologue, DHX9 contain two tandem double-stranded RNA binding domains (dsRBDs) located at the N-terminal region. The two dsRBDs are essential for localization of MLE at the X-territory and it is presumed that this involves binding roX secondary structures. However, for dsRBD1 roX RNA binding has so far not been described. Here, we determined the solution NMR structure of dsRBD1 and dsRBD2 of MLE in tandem and investigated its role in double-stranded RNA (dsRNA) binding. Our NMR and SAXS data show that both dsRBDs act as independent structural modules in solution and are canonical, non-sequence-specific dsRBDs featuring non-canonical KKxAXK RNA binding motifs. NMR titrations combined with filter binding experiments and isothermal titration calorimetry (ITC) document the contribution of dsRBD1 to dsRNA binding in vitro. Curiously, dsRBD1 mutants in which dsRNA binding in vitro is strongly compromised do not affect roX2 RNA binding and MLE localization in cells. These data suggest alternative functions for dsRBD1 in vivo.
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Affiliation(s)
- Pravin Kumar Ankush Jagtap
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Marisa Müller
- Biomedical Center and Center for Integrated Protein Science, Ludwig-Maximilians-University, 82152 Martinsried, Germany
| | - Pawel Masiewicz
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Sören von Bülow
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Nele Merret Hollmann
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences
| | - Po-Chia Chen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Bernd Simon
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Andreas W Thomae
- Biomedical Center and Center for Integrated Protein Science, Ludwig-Maximilians-University, 82152 Martinsried, Germany
| | - Peter B Becker
- Biomedical Center and Center for Integrated Protein Science, Ludwig-Maximilians-University, 82152 Martinsried, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
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23
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Tian M, Sun J, Dong B, Lin W. Unique pH-Sensitive RNA Binder for Ratiometric Visualization of Cell Apoptosis. Anal Chem 2019; 91:10056-10063. [DOI: 10.1021/acs.analchem.9b01959] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Minggang Tian
- Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
| | - Jie Sun
- Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
| | - Baoli Dong
- Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
| | - Weiying Lin
- Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
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24
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Mohibi S, Chen X, Zhang J. Cancer the'RBP'eutics-RNA-binding proteins as therapeutic targets for cancer. Pharmacol Ther 2019; 203:107390. [PMID: 31302171 DOI: 10.1016/j.pharmthera.2019.07.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022]
Abstract
RNA-binding proteins (RBPs) play a critical role in the regulation of various RNA processes, including splicing, cleavage and polyadenylation, transport, translation and degradation of coding RNAs, non-coding RNAs and microRNAs. Recent studies indicate that RBPs not only play an instrumental role in normal cellular processes but have also emerged as major players in the development and spread of cancer. Herein, we review the current knowledge about RNA binding proteins and their role in tumorigenesis as well as the potential to target RBPs for cancer therapeutics.
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Affiliation(s)
- Shakur Mohibi
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States
| | - Xinbin Chen
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States
| | - Jin Zhang
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, United States.
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25
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Shan F, Mei S, Zhang J, Zhang X, Xu C, Liao S, Tu X. A telomerase subunit homolog La protein from
Trypanosoma brucei
plays an essential role in ribosomal biogenesis. FEBS J 2019; 286:3129-3147. [DOI: 10.1111/febs.14853] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/23/2019] [Accepted: 04/13/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Fangzhen Shan
- Hefei National Laboratory for Physical Science at Microscale School of Life Science University of Science and Technology of China Hefei China
| | - Song Mei
- Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming China
| | - Jiahai Zhang
- Hefei National Laboratory for Physical Science at Microscale School of Life Science University of Science and Technology of China Hefei China
| | | | - Chao Xu
- Hefei National Laboratory for Physical Science at Microscale School of Life Science University of Science and Technology of China Hefei China
| | - Shanhui Liao
- Hefei National Laboratory for Physical Science at Microscale School of Life Science University of Science and Technology of China Hefei China
| | - Xiaoming Tu
- Hefei National Laboratory for Physical Science at Microscale School of Life Science University of Science and Technology of China Hefei China
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26
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Meyer A, Golbik RP, Sänger L, Schmidt T, Behrens SE, Friedrich S. The RGG/RG motif of AUF1 isoform p45 is a key modulator of the protein's RNA chaperone and RNA annealing activities. RNA Biol 2019; 16:960-971. [PMID: 30951406 DOI: 10.1080/15476286.2019.1602438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The RNA-binding protein AUF1 regulates post-transcriptional gene expression by affecting the steady state and translation levels of numerous target RNAs. Remodeling of RNA structures by the largest isoform AUF1 p45 was recently demonstrated in the context of replicating RNA viruses, and involves two RNA remodeling activities, i.e. an RNA chaperone and an RNA annealing activity. AUF1 contains two non-identical RNA recognition motifs (RRM) and one RGG/RG motif located in the C-terminus. In order to determine the functional significance of each motif to AUF1's RNA-binding and remodeling activities we performed a comprehensive mutagenesis study and characterized the wildtype AUF1, and several variants thereof. We demonstrate that each motif contributes to efficient RNA binding and remodeling by AUF1 indicating a tight cooperation of the RRMs and the RGG/RG motif. Interestingly, the data identify two distinct roles for the arginine residues of the RGG/RG motif for each RNA remodeling activity. First, arginine-mediated stacking interactions promote AUF1's helix-destabilizing RNA chaperone activity. Second, the electropositive character of the arginine residues is the major driving force for the RNA annealing activity. Thus, we provide the first evidence that arginine residues of an RGG/RG motif contribute to the mechanism of RNA annealing and RNA chaperoning.
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Affiliation(s)
- Alexandra Meyer
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Ralph P Golbik
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Lennart Sänger
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Tobias Schmidt
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Sven-Erik Behrens
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Susann Friedrich
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
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27
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Verdile V, De Paola E, Paronetto MP. Aberrant Phase Transitions: Side Effects and Novel Therapeutic Strategies in Human Disease. Front Genet 2019; 10:173. [PMID: 30967892 PMCID: PMC6440380 DOI: 10.3389/fgene.2019.00173] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/18/2019] [Indexed: 12/12/2022] Open
Abstract
Phase separation is a physiological process occurring spontaneously when single-phase molecular complexes separate in two phases, a concentrated phase and a more diluted one. Eukaryotic cells employ phase transition strategies to promote the formation of intracellular territories not delimited by membranes with increased local RNA concentration, such as nucleolus, paraspeckles, P granules, Cajal bodies, P-bodies, and stress granules. These organelles contain both proteins and coding and non-coding RNAs and play important roles in different steps of the regulation of gene expression and in cellular signaling. Recently, it has been shown that most human RNA-binding proteins (RBPs) contain at least one low-complexity domain, called prion-like domain (PrLD), because proteins harboring them display aggregation properties like prion proteins. PrLDs support RBP function and contribute to liquid–liquid phase transitions that drive ribonucleoprotein granule assembly, but also render RBPs prone to misfolding by promoting the formation of pathological aggregates that lead to toxicity in specific cell types. Protein–protein and protein-RNA interactions within the separated phase can enhance the transition of RBPs into solid aberrant aggregates, thus causing diseases. In this review, we highlight the role of phase transition in human disease such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and in cancer. Moreover, we discuss novel therapeutic strategies focused to control phase transitions by preventing the conversion into aberrant aggregates. In this regard, the stimulation of chaperone machinery to disassemble membrane-less organelles, the induction of pathways that could inhibit aberrant phase separation, and the development of antisense oligonucleotides (ASOs) to knockdown RNAs could be evaluated as novel therapeutic strategies for the treatment of those human diseases characterized by aberrant phase transition aggregates.
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Affiliation(s)
- Veronica Verdile
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Elisa De Paola
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Maria Paola Paronetto
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
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28
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Campagne S, Krepl M, Sponer J, Allain FHT. Combining NMR Spectroscopy and Molecular Dynamic Simulations to Solve and Analyze the Structure of Protein-RNA Complexes. Methods Enzymol 2018; 614:393-422. [PMID: 30611432 DOI: 10.1016/bs.mie.2018.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding the RNA binding specificity of protein is of primary interest to decipher their function in the cell. Here, we review the methodology used to solve the structures of protein-RNA complexes using solution-state NMR spectroscopy: from sample preparation to structure calculation procedures. We also describe how molecular dynamics simulations can help providing additional information on the role of key amino acid side chains and of water molecules in protein-RNA recognition.
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Affiliation(s)
- Sebastien Campagne
- Department of Biology, ETH Zürich, Institute of Molecular Biology and Biophysics, Zürich, Switzerland.
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic; Department of Physical Chemistry, Faculty of Science, Regional Centre of Advanced Technologies and Materials, Palacky University Olomouc, Olomouc, Czech Republic.
| | - Jiri Sponer
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic; Department of Physical Chemistry, Faculty of Science, Regional Centre of Advanced Technologies and Materials, Palacky University Olomouc, Olomouc, Czech Republic.
| | - Frederic H-T Allain
- Department of Biology, ETH Zürich, Institute of Molecular Biology and Biophysics, Zürich, Switzerland.
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29
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Vasaturo M, Cotugno R, Fiengo L, Vinegoni C, Dal Piaz F, De Tommasi N. The anti-tumor diterpene oridonin is a direct inhibitor of Nucleolin in cancer cells. Sci Rep 2018; 8:16735. [PMID: 30425290 PMCID: PMC6233161 DOI: 10.1038/s41598-018-35088-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/25/2018] [Indexed: 11/15/2022] Open
Abstract
The bioactive plant diterpene oridonin displays important pharmacological activities and is widely used in traditional Chinese medicine; however, its molecular mechanism of action is still incompletely described. In vitro and in vivo data have demonstrated anti-tumor activity of oridonin and its ability to interfere with several cell pathways; however, presently only the molecular chaperone HSP70 has been identified as a direct potential target of this compound. Here, using a combination of different proteomic approaches, innovative Cellular Thermal Shift Assay (CETSA) experiments, and classical biochemical methods, we demonstrate that oridonin interacts with Nucleolin, effectively modulating the activity of this multifunctional protein. The ability of oridonin to target Nucleolin and/or HSP70 could account for the bioactivity profile of this plant diterpene. Recently, Nucleolin has attracted attention as a druggable target, as its diverse functions are implicated in pathological processes such as cancer, inflammation, and viral infection. However, up to now, no small molecule as Nucleolin binders has been reported, thus our finding represents the first evidence of Nucleolin modulation by a small inhibitor.
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Affiliation(s)
- Michele Vasaturo
- Università degli Studi di Salerno, Department of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
- Università degli Studi di Salerno, Ph. D. School of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
| | - Roberta Cotugno
- Università degli Studi di Salerno, Department of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
| | - Lorenzo Fiengo
- Università degli Studi di Salerno, Department of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
- Università degli Studi di Salerno, Ph. D. School of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
| | - Claudio Vinegoni
- Harvard Medical School, MGH Center for Systems Biology, 185 Cambridge Steet, 02144, Boston, MA, USA
| | - Fabrizio Dal Piaz
- Università degli Studi di Salerno, Department of Medicine and Surgery, Via S. Allende, 84081, Baronissi, (SA), Italy.
| | - Nunziatina De Tommasi
- Università degli Studi di Salerno, Department of Pharmacy, Via Giovanni Paolo II, 84084, Fisciano, (SA), Italy
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30
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Zhang Q, Chen ZS, An Y, Liu H, Hou Y, Li W, Lau KF, Koon AC, Ngo JCK, Chan HYE. A peptidylic inhibitor for neutralizing expanded CAG RNA-induced nucleolar stress in polyglutamine diseases. RNA (NEW YORK, N.Y.) 2018; 24:486-498. [PMID: 29295891 PMCID: PMC5855950 DOI: 10.1261/rna.062703.117] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 12/27/2017] [Indexed: 06/07/2023]
Abstract
Polyglutamine (polyQ) diseases are a class of progressive neurodegenerative disorders characterized by the expression of both expanded CAG RNA and misfolded polyQ protein. We previously reported that the direct interaction between expanded CAG RNA and nucleolar protein nucleolin (NCL) impedes preribosomal RNA (pre-rRNA) transcription, and eventually triggers nucleolar stress-induced apoptosis in polyQ diseases. Here, we report that a 21-amino acid peptide, named "beta-structured inhibitor for neurodegenerative diseases" (BIND), effectively suppresses toxicity induced by expanded CAG RNA. When administered to a cell model, BIND potently inhibited cell death induced by expanded CAG RNA with an IC50 value of ∼0.7 µM. We showed that the function of BIND is dependent on Glu2, Lys13, Gly14, Ile18, Glu19, and Phe20. BIND treatment restored the subcellular localization of nucleolar marker protein and the expression level of pre-45s rRNA Through isothermal titration calorimetry analysis, we demonstrated that BIND suppresses nucleolar stress via a direct interaction with CAG RNA in a length-dependent manner. The mean binding constants (KD) of BIND to SCA2CAG22 , SCA2CAG42 , SCA2CAG55 , and SCA2CAG72 RNA are 17.28, 5.60, 4.83, and 0.66 µM, respectively. In vivo, BIND ameliorates retinal degeneration and climbing defects, and extends the lifespan of Drosophila expressing expanded CAG RNA. These effects suggested that BIND can suppress neurodegeneration in diverse polyQ disease models in vivo and in vitro without exerting observable cytotoxic effect. Our results collectively demonstrated that BIND is an effective inhibitor of expanded CAG RNA-induced toxicity in polyQ diseases.
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Affiliation(s)
- Qian Zhang
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhefan Stephen Chen
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ying An
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Haizhen Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Yonghui Hou
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Wen Li
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Kwok-Fai Lau
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Alex Chun Koon
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila Research, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
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31
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Zhu G, Liu W, Bao C, Tong D, Ji H, Shen Z, Yang D, Lu L. Investigating energy-based pool structure selection in the structure ensemble modeling with experimental distance constraints: The example from a multidomain protein Pub1. Proteins 2018; 86:501-514. [PMID: 29383828 DOI: 10.1002/prot.25468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 12/26/2017] [Accepted: 01/23/2018] [Indexed: 12/25/2022]
Abstract
The structural variations of multidomain proteins with flexible parts mediate many biological processes, and a structure ensemble can be determined by selecting a weighted combination of representative structures from a simulated structure pool, producing the best fit to experimental constraints such as interatomic distance. In this study, a hybrid structure-based and physics-based atomistic force field with an efficient sampling strategy is adopted to simulate a model di-domain protein against experimental paramagnetic relaxation enhancement (PRE) data that correspond to distance constraints. The molecular dynamics simulations produce a wide range of conformations depicted on a protein energy landscape. Subsequently, a conformational ensemble recovered with low-energy structures and the minimum-size restraint is identified in good agreement with experimental PRE rates, and the result is also supported by chemical shift perturbations and small-angle X-ray scattering data. It is illustrated that the regularizations of energy and ensemble-size prevent an arbitrary interpretation of protein conformations. Moreover, energy is found to serve as a critical control to refine the structure pool and prevent data overfitting, because the absence of energy regularization exposes ensemble construction to the noise from high-energy structures and causes a more ambiguous representation of protein conformations. Finally, we perform structure-ensemble optimizations with a topology-based structure pool, to enhance the understanding on the ensemble results from different sources of pool candidates.
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Affiliation(s)
- Guanhua Zhu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Wei Liu
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Chenglong Bao
- Department of Mathematics, National University of Singapore, 10 Lower Kent Ridge Road, Singapore, 119076, Singapore.,Yau Mathematical Sciences Center, Tsinghua University, Haidian District, Beijing, 100084, China
| | - Dudu Tong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Hui Ji
- Department of Mathematics, National University of Singapore, 10 Lower Kent Ridge Road, Singapore, 119076, Singapore
| | - Zuowei Shen
- Department of Mathematics, National University of Singapore, 10 Lower Kent Ridge Road, Singapore, 119076, Singapore
| | - Daiwen Yang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
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32
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Sofi S, Stehling S, Niewienda A, Janek K, Kuhn H, Ufer C. Functional characterization of isolated RNA-binding domains of the GRSF1 protein. Biochim Biophys Acta Gen Subj 2017; 1862:946-957. [PMID: 29288125 DOI: 10.1016/j.bbagen.2017.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/20/2017] [Accepted: 12/22/2017] [Indexed: 11/26/2022]
Abstract
The Guanine-rich RNA sequence binding factor 1 (GRSF1) is a member of the heterogeneous nuclear ribonucleoprotein F/H family and has been implicated in RNA processing, RNA transport and translational regulation. Amino acid alignments and homology modeling suggested the existence of three distinct RNA-binding domains and two auxiliary domains. Unfortunately, little is known about the molecular details of GRSF1/RNA interactions. To explore the RNA-binding mechanisms we first expressed full-length human GRSF1 and several truncation mutants, which include the three separated qRRM domains in E. coli, purified the recombinant proteins and quantified their RNA-binding affinity by RNA electrophoretic mobility shift assays. The expression levels varied between 1 and 10mg purified protein per L bacterial liquid culture and for full-length human GRSF1 a binding constant (KD-value) of 0.5μM was determined. In addition, our mechanistic experiments with different truncation mutants allowed the following conclusions: i) Deletion of either of the three RNA-binding domains impaired the RNA-binding affinity suggesting that the simultaneous presence of the three domains is essential for high-affinity RNA-binding. ii) Deletion of the Ala-rich auxiliary domain did hardly affect RNA-binding. Thus, this structural subunit may not be involved in RNA interaction. iii) Deletion of the acidic auxiliary domain improved the RNA-binding suggesting a regulatory role for this structural motif. iv) The isolated RNA-binding domains did not exhibit sizeable RNA-binding affinities. Taken together these data suggest that a cooperative interaction of the three qRRMs is required for high affinity RNA-binding.
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Affiliation(s)
- Sajad Sofi
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Sabine Stehling
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Agathe Niewienda
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Shared Facility for Mass Spectrometry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Katharina Janek
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Shared Facility for Mass Spectrometry, Chariteplatz 1, D-10117 Berlin, Germany
| | - Hartmut Kuhn
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Christoph Ufer
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Biochemistry, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
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33
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Dilworth D, Upadhyay SK, Bonnafous P, Edoo AB, Bourbigot S, Pesek-Jardim F, Gudavicius G, Serpa JJ, Petrotchenko EV, Borchers CH, Nelson CJ, Mackereth CD. The basic tilted helix bundle domain of the prolyl isomerase FKBP25 is a novel double-stranded RNA binding module. Nucleic Acids Res 2017; 45:11989-12004. [PMID: 29036638 PMCID: PMC5714180 DOI: 10.1093/nar/gkx852] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 09/13/2017] [Indexed: 11/14/2022] Open
Abstract
Prolyl isomerases are defined by a catalytic domain that facilitates the cis–trans interconversion of proline residues. In most cases, additional domains in these enzymes add important biological function, including recruitment to a set of protein substrates. Here, we report that the N-terminal basic tilted helix bundle (BTHB) domain of the human prolyl isomerase FKBP25 confers specific binding to double-stranded RNA (dsRNA). This binding is selective over DNA as well as single-stranded oligonucleotides. We find that FKBP25 RNA-association is required for its nucleolar localization and for the vast majority of its protein interactions, including those with 60S pre-ribosome and early ribosome biogenesis factors. An independent mobility of the BTHB and FKBP catalytic domains supports a model by which the N-terminus of FKBP25 is anchored to regions of dsRNA, whereas the FKBP domain is free to interact with neighboring proteins. Apart from the identification of the BTHB as a new dsRNA-binding module, this domain adds to the growing list of auxiliary functions used by prolyl isomerases to define their primary cellular targets.
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Affiliation(s)
- David Dilworth
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Santosh K Upadhyay
- Univ. Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France.,Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France.,CSIR-Institute of Genomics and Integrative Biology, New Delhi 110020, India
| | - Pierre Bonnafous
- Univ. Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France.,Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Amiirah Bibi Edoo
- Univ. Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France.,Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Sarah Bourbigot
- Univ. Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France.,Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Francy Pesek-Jardim
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Geoff Gudavicius
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Jason J Serpa
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada.,University of Victoria Genome BC Proteomics Centre, Vancouver Island Technology Park, Victoria, BC V8Z 7X8, Canada
| | - Evgeniy V Petrotchenko
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada.,University of Victoria Genome BC Proteomics Centre, Vancouver Island Technology Park, Victoria, BC V8Z 7X8, Canada
| | - Christoph H Borchers
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada.,University of Victoria Genome BC Proteomics Centre, Vancouver Island Technology Park, Victoria, BC V8Z 7X8, Canada
| | - Christopher J Nelson
- Dept. of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Cameron D Mackereth
- Univ. Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France.,Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
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34
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Sloutsky R, Naegle KM. Proteome-Level Analysis Indicates Global Mechanisms for Post-Translational Regulation of RRM Domains. J Mol Biol 2017; 430:41-44. [PMID: 29146174 DOI: 10.1016/j.jmb.2017.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/19/2017] [Accepted: 11/06/2017] [Indexed: 12/22/2022]
Abstract
RRM, or RNA-recognition motif, domains are the largest class of single-stranded RNA binding domains in the human proteome and play important roles in RNA processing, splicing, export, stability, packaging, and degradation. Using a current database of post-translational modifications (PTMs), ProteomeScout, we found that RRM domains are also one of the most heavily modified domains in the human proteome. Here, we present two interesting findings about RRM domain modifications, found by mapping known PTMs onto RRM domain alignments and structures. First, we find significant overlap of ubiquitination and acetylation within RRM domains, suggesting the possibility for ubiquitination-acetylation crosstalk. Additionally, an analysis of quantitative study of ubiquitination changes in response to proteasome inhibition highlights the uniqueness of RRM domain ubiquitination - RRM domain ubiquitination decreases in response to proteasome inhibition, whereas the majority of sites increase. Second, we found conservation of tyrosine phosphorylation within the RNP1 and RNP2 consensus sequences, which coordinate RNA binding - suggesting a possible role for regulation of RNA binding by tyrosine kinase signaling. These observations suggest there are unique regulatory mechanisms of RRM function that have yet to be uncovered and that the RRM domain represents a model system for further studies on understanding PTM crosstalk.
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Affiliation(s)
- Roman Sloutsky
- Biomedical Engineering and the Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA; Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Kristen M Naegle
- Biomedical Engineering and the Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
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35
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Ugrinova I, Petrova M, Chalabi-Dchar M, Bouvet P. Multifaceted Nucleolin Protein and Its Molecular Partners in Oncogenesis. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 111:133-164. [PMID: 29459030 DOI: 10.1016/bs.apcsb.2017.08.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Discovered in 1973, nucleolin is one of the most abundant phosphoproteins of the nucleolus. The ability of nucleolin to be involved in many cellular processes is probably related to its structural organization and its capability to form many different interactions with other proteins. Many functions of nucleolin affect cellular processes involved in oncogenesis-for instance: in ribosome biogenesis; in DNA repair, remodeling, and genome stability; in cell division and cell survival; in chemokine and growth factor signaling pathways; in angiogenesis and lymphangiogenesis; in epithelial-mesenchymal transition; and in stemness. In this review, we will describe the different functions of nucleolin in oncogenesis through its interaction with other proteins.
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Affiliation(s)
- Iva Ugrinova
- "Roumen Tsanev" Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
| | - Maria Petrova
- "Roumen Tsanev" Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Mounira Chalabi-Dchar
- Université de Lyon, Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, Lyon, France
| | - Philippe Bouvet
- Université de Lyon, Ecole Normale Supérieure de Lyon, Lyon, France
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Jia W, Yao Z, Zhao J, Guan Q, Gao L. New perspectives of physiological and pathological functions of nucleolin (NCL). Life Sci 2017; 186:1-10. [PMID: 28751161 DOI: 10.1016/j.lfs.2017.07.025] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 12/13/2022]
Abstract
Nucleolin (NCL) is a multifunctional protein that mainly localized in the nucleolus, it is also found in the nucleoplasm, cytoplasm and cell membrane. The three main structural domains allow the interaction of NCL with different proteins and RNA sequences. Moreover, specific post-translational modifications and its shuttling property also contribute to its multifunctionality. NCL has been demonstrated to be involved in a variety of aspects such as ribosome biogenesis, chromatin organization and stability, DNA and RNA metabolism, cytokinesis, cell proliferation, angiogenesis, apoptosis regulation, stress response and microRNA processing. NCL has been increasingly implicated in several pathological processes, especially in tumorigenesis and viral infection, which makes NCL a potential target for the development of anti-tumor and anti-viral strategies. In this review, we present an overview on the structure, localizations and various functions of NCL, and further describe how the multiple functions of NCL are correlated to its multiple cellular distributions.
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Affiliation(s)
- Wenyu Jia
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong Province, PR China; Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong Province, PR China; Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong Province, PR China
| | - Zhenyu Yao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong Province, PR China; Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong Province, PR China; Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong Province, PR China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong Province, PR China; Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong Province, PR China; Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong Province, PR China
| | - Qingbo Guan
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong Province, PR China; Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong Province, PR China; Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong Province, PR China
| | - Ling Gao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong Province, PR China; Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong Province, PR China; Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong Province, PR China.
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Blewett NH, Iben JR, Gaidamakov S, Maraia RJ. La Deletion from Mouse Brain Alters Pre-tRNA Metabolism and Accumulation of Pre-5.8S rRNA, with Neuron Death and Reactive Astrocytosis. Mol Cell Biol 2017; 37:e00588-16. [PMID: 28223366 PMCID: PMC5477551 DOI: 10.1128/mcb.00588-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/01/2016] [Accepted: 02/06/2017] [Indexed: 12/20/2022] Open
Abstract
Human La antigen (Sjögren's syndrome antigen B [SSB]) is an abundant multifunctional RNA-binding protein. In the nucleoplasm, La binds to and protects from 3' exonucleases, the ends of precursor tRNAs, and other transcripts synthesized by RNA polymerase III and facilitates their maturation, while a nucleolar isoform has been implicated in rRNA biogenesis by multiple independent lines of evidence. We showed previously that conditional La knockout (La cKO) from mouse cortex neurons results in defective tRNA processing, although the pathway(s) involved in neuronal loss thereafter was unknown. Here, we demonstrate that La is stably associated with a spliced pre-tRNA intermediate. Microscopic evidence of aberrant nuclear accumulation of 5.8S rRNA in La cKO is supported by a 10-fold increase in a pre-5.8S rRNA intermediate. To identify pathways involved in subsequent neurodegeneration and loss of brain mass in the cKO cortex, we employed mRNA sequencing (mRNA-Seq), immunohistochemistry, and other approaches. This revealed robust enrichment of immune and astrocyte reactivity in La cKO cortex. Immunohistochemistry, including temporal analyses, demonstrated neurodegeneration, followed by astrocyte invasion associated with immune response and decreasing cKO cortex size over time. Thus, deletion of La from postmitotic neurons results in defective pre-tRNA and pre-rRNA processing and progressive neurodegeneration with loss of cortical brain mass.
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Affiliation(s)
- Nathan H Blewett
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - James R Iben
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - Sergei Gaidamakov
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - Richard J Maraia
- Commissioned Corps, U.S. Public Health Service, Rockville, Maryland, USA
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Krepl M, Cléry A, Blatter M, Allain FHT, Sponer J. Synergy between NMR measurements and MD simulations of protein/RNA complexes: application to the RRMs, the most common RNA recognition motifs. Nucleic Acids Res 2016; 44:6452-70. [PMID: 27193998 PMCID: PMC5291263 DOI: 10.1093/nar/gkw438] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/30/2016] [Accepted: 05/05/2016] [Indexed: 01/28/2023] Open
Abstract
RNA recognition motif (RRM) proteins represent an abundant class of proteins playing key roles in RNA biology. We present a joint atomistic molecular dynamics (MD) and experimental study of two RRM-containing proteins bound with their single-stranded target RNAs, namely the Fox-1 and SRSF1 complexes. The simulations are used in conjunction with NMR spectroscopy to interpret and expand the available structural data. We accumulate more than 50 μs of simulations and show that the MD method is robust enough to reliably describe the structural dynamics of the RRM-RNA complexes. The simulations predict unanticipated specific participation of Arg142 at the protein-RNA interface of the SRFS1 complex, which is subsequently confirmed by NMR and ITC measurements. Several segments of the protein-RNA interface may involve competition between dynamical local substates rather than firmly formed interactions, which is indirectly consistent with the primary NMR data. We demonstrate that the simulations can be used to interpret the NMR atomistic models and can provide qualified predictions. Finally, we propose a protocol for 'MD-adapted structure ensemble' as a way to integrate the simulation predictions and expand upon the deposited NMR structures. Unbiased μs-scale atomistic MD could become a technique routinely complementing the NMR measurements of protein-RNA complexes.
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Affiliation(s)
- Miroslav Krepl
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Antoine Cléry
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Markus Blatter
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland Global Discovery Chemistry, Novartis Institute for BioMedical Research, Basel CH-4002, Switzerland
| | - Frederic H T Allain
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Jiri Sponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, 625 00 Brno, Czech Republic
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Mitrea DM, Kriwacki RW. Phase separation in biology; functional organization of a higher order. Cell Commun Signal 2016; 14:1. [PMID: 26727894 PMCID: PMC4700675 DOI: 10.1186/s12964-015-0125-7] [Citation(s) in RCA: 448] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/29/2015] [Indexed: 12/18/2022] Open
Abstract
Inside eukaryotic cells, macromolecules are partitioned into membrane-bounded compartments and, within these, some are further organized into non-membrane-bounded structures termed membrane-less organelles. The latter structures are comprised of heterogeneous mixtures of proteins and nucleic acids and assemble through a phase separation phenomenon similar to polymer condensation. Membrane-less organelles are dynamic structures maintained through multivalent interactions that mediate diverse biological processes, many involved in RNA metabolism. They rapidly exchange components with the cellular milieu and their properties are readily altered in response to environmental cues, often implicating membrane-less organelles in responses to stress signaling. In this review, we discuss: (1) the functional roles of membrane-less organelles, (2) unifying structural and mechanistic principles that underlie their assembly and disassembly, and (3) established and emerging methods used in structural investigations of membrane-less organelles.
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Affiliation(s)
- Diana M Mitrea
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA.
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40
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Kashyap M, Ganguly AK, Bhavesh NS. Structural delineation of stem-loop RNA binding by human TAF15 protein. Sci Rep 2015; 5:17298. [PMID: 26612539 PMCID: PMC4661536 DOI: 10.1038/srep17298] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/28/2015] [Indexed: 11/09/2022] Open
Abstract
Human TATA binding protein associated factor 2 N (TAF15) and Fused in sarcoma (FUS) are nucleic acid binding proteins belonging to the conserved FET family of proteins. They are involved in diverse processes such as pre-mRNA splicing, mRNA transport, and DNA binding. The absence of information regarding the structural mechanism employed by the FET family in recognizing and discriminating their cognate and non-cognate RNA targets has hampered the attainment of consensus on modes of protein-RNA binding for this family. Our study provides a molecular basis of this RNA recognition using a combination of solution-state NMR spectroscopy, calorimetry, docking and molecular dynamics simulation. Analysis of TAF15-RRM solution structure and its binding with stem-loop RNA has yielded conclusive evidence of a non-canonical mode of RNA recognition. Rather than classical stacking interactions that occur across nitrogen bases and aromatic amino acids on ribonucleoprotein sites, moderate-affinity hydrogen bonding network between the nitrogen bases in the stem-loop RNA and a concave face on the RRM surface primarily mediate TAF15-RRM RNA interaction. We have compared the binding affinities across a set of single-stranded RNA oligonucleotides to conclusively establish that RNA binding is dependent upon structural elements in the RNA rather than sequence.
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Affiliation(s)
- Maruthi Kashyap
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, 110 067, New Delhi, India
| | - Akshay Kumar Ganguly
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, 110 067, New Delhi, India
| | - Neel Sarovar Bhavesh
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, 110 067, New Delhi, India
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41
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Tosoni E, Frasson I, Scalabrin M, Perrone R, Butovskaya E, Nadai M, Palù G, Fabris D, Richter SN. Nucleolin stabilizes G-quadruplex structures folded by the LTR promoter and silences HIV-1 viral transcription. Nucleic Acids Res 2015; 43:8884-97. [PMID: 26354862 PMCID: PMC4605322 DOI: 10.1093/nar/gkv897] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 08/26/2015] [Accepted: 08/27/2015] [Indexed: 01/26/2023] Open
Abstract
Folding of the LTR promoter into dynamic G-quadruplex conformations has been shown to suppress its transcriptional activity in HIV-1. Here we sought to identify the proteins that control the folding of this region of proviral genome by inducing/stabilizing G-quadruplex structures. The implementation of electrophorethic mobility shift assay and pull-down experiments coupled with mass spectrometric analysis revealed that the cellular protein nucleolin is able to specifically recognize G-quadruplex structures present in the LTR promoter. Nucleolin recognized with high affinity and specificity the majority, but not all the possible G-quadruplexes folded by this sequence. In addition, it displayed greater binding preference towards DNA than RNA G-quadruplexes, thus indicating two levels of selectivity based on the sequence and nature of the target. The interaction translated into stabilization of the LTR G-quadruplexes and increased promoter silencing activity; in contrast, disruption of nucleolin binding in cells by both siRNAs and a nucleolin binding aptamer greatly increased LTR promoter activity. These data indicate that nucleolin possesses a specific and regulated activity toward the HIV-1 LTR promoter, which is mediated by G-quadruplexes. These observations provide new essential insights into viral transcription and a possible low mutagenic target for antiretroviral therapy.
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Affiliation(s)
- Elena Tosoni
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Ilaria Frasson
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Matteo Scalabrin
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Rosalba Perrone
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Elena Butovskaya
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Matteo Nadai
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
| | - Dan Fabris
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - Sara N Richter
- Department of Molecular Medicine, University of Padua, via Gabelli 63, 35121 Padua, Italy
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Varadi M, Zsolyomi F, Guharoy M, Tompa P. Functional Advantages of Conserved Intrinsic Disorder in RNA-Binding Proteins. PLoS One 2015; 10:e0139731. [PMID: 26439842 PMCID: PMC4595337 DOI: 10.1371/journal.pone.0139731] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/15/2015] [Indexed: 11/22/2022] Open
Abstract
Proteins form large macromolecular assemblies with RNA that govern essential molecular processes. RNA-binding proteins have often been associated with conformational flexibility, yet the extent and functional implications of their intrinsic disorder have never been fully assessed. Here, through large-scale analysis of comprehensive protein sequence and structure datasets we demonstrate the prevalence of intrinsic structural disorder in RNA-binding proteins and domains. We addressed their functionality through a quantitative description of the evolutionary conservation of disordered segments involved in binding, and investigated the structural implications of flexibility in terms of conformational stability and interface formation. We conclude that the functional role of intrinsically disordered protein segments in RNA-binding is two-fold: first, these regions establish extended, conserved electrostatic interfaces with RNAs via induced fit. Second, conformational flexibility enables them to target different RNA partners, providing multi-functionality, while also ensuring specificity. These findings emphasize the functional importance of intrinsically disordered regions in RNA-binding proteins.
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Affiliation(s)
- Mihaly Varadi
- Structural Biology Research Center (SBRC), Flemish Institute of Biotechnology (VIB), Brussels, Belgium; Structural Biology Brussel (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Fruzsina Zsolyomi
- Structural Biology Research Center (SBRC), Flemish Institute of Biotechnology (VIB), Brussels, Belgium; Structural Biology Brussel (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Mainak Guharoy
- Structural Biology Research Center (SBRC), Flemish Institute of Biotechnology (VIB), Brussels, Belgium; Structural Biology Brussel (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- Structural Biology Research Center (SBRC), Flemish Institute of Biotechnology (VIB), Brussels, Belgium; Structural Biology Brussel (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium; Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
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43
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Blythe AJ, Fox AH, Bond CS. The ins and outs of lncRNA structure: How, why and what comes next? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:46-58. [PMID: 26325022 DOI: 10.1016/j.bbagrm.2015.08.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/07/2015] [Accepted: 08/27/2015] [Indexed: 12/20/2022]
Abstract
The field of structural biology has the unique advantage of being able to provide a comprehensive picture of biological mechanisms at the molecular and atomic level. Long noncoding RNAs (lncRNAs) represent the new frontier in the molecular biology of complex organisms yet remain the least characterised of all the classes of RNA. Thousands of new lncRNAs are being reported each year yet very little structural data exists for this rapidly expanding field. The length of lncRNAs ranges from 200 nt to over 100 kb in length and they generally exhibit low cellular abundance. Therefore, obtaining sufficient quantities of lncRNA to use for structural analysis is challenging. However, as technologies develop structures of lncRNAs are starting to emerge providing important information regarding their mechanism of action. Here we review the current methods used to determine the structure of lncRNA and lncRNA:protein complexes and describe the significant contribution structural biology has and will make to the field of lncRNA research. This article is part of a Special Issue entitled: Clues to long noncoding RNA taxonomy1, edited by Dr. Tetsuro Hirose and Dr. Shinichi Nakagawa.
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Affiliation(s)
- Amanda J Blythe
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia.
| | - Archa H Fox
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Charles S Bond
- School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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Abstract
RRM-containing proteins are involved in most of the RNA metabolism steps. Their functions are closely related to their mode of RNA recognition, which has been studied by structural biologists for more than 20 years. In this chapter, we report on high-resolution structures of single and multi RRM-RNA complexes to explain the numerous strategies used by these domains to interact specifically with a large repertoire of RNA sequences. We show that multiple variations of their canonical fold can be used to adapt to different single-stranded sequences with a large range of affinities. Furthermore, we describe the consequences on RNA binding of the different structural arrangements found in tandem RRMs and higher order RNPs. Importantly, these structures also reveal with very high accuracy the RNA motifs bound specifically by RRM-containing proteins, which correspond very often to consensus sequences identified with genome-wide approaches. Finally, we show how structural and cellular biology can benefit from each other and pave a way for understanding, defining, and predicting a code of RNA recognition by the RRMs.
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45
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Durut N, Sáez-Vásquez J. Nucleolin: dual roles in rDNA chromatin transcription. Gene 2015; 556:7-12. [PMID: 25225127 DOI: 10.1016/j.gene.2014.09.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/08/2014] [Accepted: 09/09/2014] [Indexed: 01/17/2023]
Abstract
Nucleolin is a major nucleolar protein conserved in all eukaryotic organisms. It is a multifunctional protein involved in different cellular aspects like chromatin organization and stability, DNA and RNA metabolism, assembly of ribonucleoprotein complexes, cytokinesis, cell proliferation and stress response. The multifunctionality of nucleolin is linked to its tripartite structure, post-translational modifications and its ability of shuttling from and to the nucleolus/nucleoplasm and cytoplasm. Nucleolin has been now studied for many years and its activities and properties have been described in a number of excellent reviews. Here, we overview the role of nucleolin in RNA polymerase I (RNAPI) transcription and describe recent results concerning its functional interaction with rDNA chromatin organization. For a long time, nucleolin has been associated with rRNA gene expression and pre-rRNA processing. However, the functional connection between nucleolin and active versus inactive rRNA genes is still not fully understood. Novel evidence indicates that the nucleolin protein might be required for controlling the transcriptional ON/OFF states of rDNA chromatin in both mammals and plants.
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Affiliation(s)
- Nathalie Durut
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France; Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Julio Sáez-Vásquez
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France; Univ. Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France.
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46
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Anshu A, Mannan MAU, Chakraborty A, Chakrabarti S, Dey M. A novel role for protein kinase Kin2 in regulating HAC1 mRNA translocation, splicing, and translation. Mol Cell Biol 2015; 35:199-210. [PMID: 25348718 PMCID: PMC4295377 DOI: 10.1128/mcb.00981-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/13/2014] [Accepted: 10/06/2014] [Indexed: 12/23/2022] Open
Abstract
A signaling network called the unfolded protein response (UPR) resolves the protein-folding defects in the endoplasmic reticulum (ER) from yeasts to humans. In the yeast Saccharomyces cerevisiae, the UPR activation involves (i) aggregation of the ER-resident kinase/RNase Ire1 to form an Ire1 focus, (ii) targeting HAC1 pre-mRNA toward the Ire1 focus that cleaves out an inhibitory intron from the mRNA, and (iii) translation of Hac1 protein from the spliced mRNA. Targeting HAC1 mRNA to the Ire1 focus requires a cis-acting bipartite element (3'BE) located at the 3' untranslated leader. Here, we report that the 3'BE plays an additional role in promoting translation from the spliced mRNA. We also report that a high dose of either of two paralogue kinases, Kin1 and Kin2, overcomes the defective UPR caused by a mutation in the 3'BE. These results define a novel role for Kin kinases in the UPR beyond their role in cell polarity and exocytosis. Consistently, targeting, splicing, and translation of HAC1 mRNA are substantially reduced in the kin1Δ kin2Δ strain. Furthermore, we show that Kin2 kinase domain itself is sufficient to activate the UPR, suggesting that Kin2 initiates a signaling cascade to ensure an optimum UPR.
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Affiliation(s)
- Ashish Anshu
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - M Amin-Ul Mannan
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | | | | | - Madhusudan Dey
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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47
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Zearfoss NR, Deveau LM, Clingman CC, Schmidt E, Johnson ES, Massi F, Ryder SP. A conserved three-nucleotide core motif defines Musashi RNA binding specificity. J Biol Chem 2014; 289:35530-41. [PMID: 25368328 DOI: 10.1074/jbc.m114.597112] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Musashi (MSI) family proteins control cell proliferation and differentiation in many biological systems. They are overexpressed in tumors of several origins, and their expression level correlates with poor prognosis. MSI proteins control gene expression by binding RNA and regulating its translation. They contain two RNA recognition motif (RRM) domains, which recognize a defined sequence element. The relative contribution of each nucleotide to the binding affinity and specificity is unknown. We analyzed the binding specificity of three MSI family RRM domains using a quantitative fluorescence anisotropy assay. We found that the core element driving recognition is the sequence UAG. Nucleotides outside of this motif have a limited contribution to binding free energy. For mouse MSI1, recognition is determined by the first of the two RRM domains. The second RRM adds affinity but does not contribute to binding specificity. In contrast, the recognition element for Drosophila MSI is more extensive than the mouse homolog, suggesting functional divergence. The short nature of the binding determinant suggests that protein-RNA affinity alone is insufficient to drive target selection by MSI family proteins.
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Affiliation(s)
- N Ruth Zearfoss
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Laura M Deveau
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Carina C Clingman
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Eric Schmidt
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Emily S Johnson
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Francesca Massi
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Sean P Ryder
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
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48
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Schelhorn C, Gordon JMB, Ruiz L, Alguacil J, Pedroso E, Macias MJ. RNA recognition and self-association of CPEB4 is mediated by its tandem RRM domains. Nucleic Acids Res 2014; 42:10185-95. [PMID: 25081215 PMCID: PMC4150798 DOI: 10.1093/nar/gku700] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/11/2014] [Accepted: 07/19/2014] [Indexed: 11/12/2022] Open
Abstract
Cytoplasmic polyadenylation is regulated by the interaction of the cytoplasmic polyadenylation element binding proteins (CPEB) with cytoplasmic polyadenylation element (CPE) containing mRNAs. The CPEB family comprises four paralogs, CPEB1-4, each composed of a variable N-terminal region, two RNA recognition motif (RRM) and a C-terminal ZZ-domain. We have characterized the RRM domains of CPEB4 and their binding properties using a combination of biochemical, biophysical and NMR techniques. Isothermal titration calorimetry, NMR and electrophoretic mobility shift assay experiments demonstrate that both the RRM domains are required for an optimal CPE interaction and the presence of either one or two adenosines in the two most commonly used consensus CPE motifs has little effect on the affinity of the interaction. Both the single RRM1 and the tandem RRM1-RRM2 have the ability to dimerize, although representing a minor population. Self-association does not affect the proteins' ability to interact with RNA as demonstrated by ion mobility-mass spectrometry. Chemical shift effects measured by NMR of the apo forms of the RRM1-RRM2 samples indicate that the two domains are orientated toward each other. NMR titration experiments show that residues on the β-sheet surface on RRM1 and at the C-terminus of RRM2 are affected upon RNA binding. We propose a model of the CPEB4 RRM1-RRM2-CPE complex that illustrates the experimental data.
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Affiliation(s)
- Constanze Schelhorn
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - James M B Gordon
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Lidia Ruiz
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Javier Alguacil
- Departament de Química Orgànica and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Enrique Pedroso
- Departament de Química Orgànica and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Maria J Macias
- Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluis Companys 23, Barcelona 08010, Spain
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Yuan W, Lok JB, Stoltzfus JD, Gasser RB, Fang F, Lei WQ, Fang R, Zhou YQ, Zhao JL, Hu M. Toward understanding the functional role of Ss-RIOK-1, a RIO protein kinase-encoding gene of Strongyloides stercoralis. PLoS Negl Trop Dis 2014; 8:e3062. [PMID: 25101874 PMCID: PMC4125297 DOI: 10.1371/journal.pntd.0003062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/17/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Some studies of Saccharomyces cerevisiae and mammals have shown that RIO protein kinases (RIOKs) are involved in ribosome biogenesis, cell cycle progression and development. However, there is a paucity of information on their functions in parasitic nematodes. We aimed to investigate the function of RIOK-1 encoding gene from Strongyloides stercoralis, a nematode parasitizing humans and dogs. METHODOLOGY/PRINCIPAL FINDINGS The RIOK-1 protein-encoding gene Ss-riok-1 was characterized from S. stercoralis. The full-length cDNA, gDNA and putative promoter region of Ss-riok-1 were isolated and sequenced. The cDNA comprises 1,828 bp, including a 377 bp 5'-UTR, a 17 bp 3'-UTR and a 1,434 bp ORF encoding a protein of 477 amino acids containing a RIOK-1 signature motif. The genomic sequence of the Ss-riok-1 coding region is 1,636 bp in length and has three exons and two introns. The putative promoter region comprises 4,280 bp and contains conserved promoter elements, including four CAAT boxes, 12 GATA boxes, eight E-boxes (CANNTG) and 38 TATA boxes. The Ss-riok-1 gene is transcribed throughout all developmental stages with the highest transcript abundance in the infective third-stage larva (iL3). Recombinant Ss-RIOK-1 is an active kinase, capable of both phosphorylation and auto-phosphorylation. Patterns of transcriptional reporter expression in transgenic S. stercoralis larvae indicated that Ss-RIOK-1 is expressed in neurons of the head, body and tail as well as in pharynx and hypodermis. CONCLUSIONS/SIGNIFICANCE The characterization of the molecular and the temporal and spatial expression patterns of the encoding gene provide first clues as to functions of RIOKs in the biological processes of parasitic nematodes.
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Affiliation(s)
- Wang Yuan
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - James B. Lok
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (JBL); (MH)
| | - Jonathan D. Stoltzfus
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Robin B. Gasser
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Fang Fang
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Wei-Qiang Lei
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Rui Fang
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yan-Qin Zhou
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jun-Long Zhao
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- * E-mail: (JBL); (MH)
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Fujiki H, Watanabe T, Suganuma M. Cell-surface nucleolin acts as a central mediator for carcinogenic, anti-carcinogenic, and disease-related ligands. J Cancer Res Clin Oncol 2014; 140:689-99. [PMID: 24469254 PMCID: PMC3983879 DOI: 10.1007/s00432-014-1587-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 01/16/2014] [Indexed: 12/14/2022]
Abstract
PURPOSE Cell-surface nucleolin in human gastric cancer cell lines is a receptor for TNF-α-inducing protein (Tipα) of Helicobacter pylori. The binding complex of nucleolin and Tipα is internalized into the cells and then induces tumor progression of human gastric cancer. Surface nucleolin is also a receptor of human immunodeficiency virus-1, and the anti-HIV pseudopeptide (HB-19) showed anti-carcinogenic activity in vivo. Surface nucleolin has dual functions depending on the ligands: In order to understand the mechanisms of surface nucleolin, it is necessary to review surface nucleolin and its relation to carcinogenic ligands and anti-carcinogenic ligands. Other ligands can be grouped among disease-related ligands, which is an important new topic for the prevention of various ailments. RESULTS AND DISCUSSION This paper mainly deals with two ligands of surface nucleolin, Tipα and pseudopeptide HB-19. The binding complex of nucleolin and Tipα induces expression of TNF-α and chemokine genes and activates NF-κB in gastric cancer cells of humans and mice. However, when human gastric cancer cell line MKN-1 was transfected with nucleolin-targeted siRNA, the result was inhibition of cell migration and elongation induced by Tipα. The amount of surface nucleolin was reduced in membrane fraction of the nucleolin knockdown MKN-1 cells, but the amount of nucleolin in the cytosol or nuclear fractions of the cells did not change. The results indicate that surface nucleolin acts as a carcinogenic mediator for Tipα of H. pylori. In contrast, both the viral external envelop glycoprotein gp120 of HIV and the anti-HIV pseudopeptide HB-19 bind to surface nucleolin. Through this binding, treatment with HB-19 inhibited tumor development in human breast cancer cell line MDA-MB-231 and rhabdoid tumor cell line derived from Wilms's tumor in xenograft nude mouse models. The results show that surface nucleolin acts as an anti-carcinogenic mediator for HB-19. CONCLUSION Based on these discrete functions of surface nucleolin, the binding complex of carcinogenic ligands and surface nucleolin seems to be competing with that of anti-carcinogenic ligands and surface nucleolin. Moreover, carcinogenic ligands derived from endogenous sources play a significant role in human cancer development, and the interaction of surface nucleolin with disease-related ligands will be a new research subject for the prevention and treatment of various ailments.
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Affiliation(s)
- Hirota Fujiki
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, 362-0806, Japan,
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