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Chakraborty A, Samant D, Sarkar R, Sangeet S, Prusty S, Roy S. RNA's Dynamic Conformational Selection and Entropic Allosteric Mechanism in Controlling Cascade Protein Binding Events. J Phys Chem Lett 2024; 15:6115-6125. [PMID: 38830201 DOI: 10.1021/acs.jpclett.4c00740] [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: 06/05/2024]
Abstract
In the TAR RNA of immunodeficiency viruses, an allosteric communication exists between a distant loop and a bulge. The bulge interacts with the TAT protein vital for transactivating viral RNA, while the loop interacts with cyclin-T1, contingent on TAT binding. Through extensive atomistic and free energy simulations, we investigate TAR-TAT binding in nonpathogenic bovine immunodeficiency virus (BIV) and pathogenic human immunodeficiency virus (HIV). Thermodynamic analysis reveals enthalpically driven binding in BIV and entropically favored binding in HIV. The broader global basin in HIV is attributed to binding-induced loop fluctuation, corroborated by nuclear magnetic resonance (NMR), indicating classical entropic allostery onset. While this loop fluctuation affects the TAT binding affinity, it generates a binding-competent conformation that aids subsequent effector (cyclin-T1) binding. This study underscores how two structurally similar apo-RNA scaffolds adopt distinct conformational selection mechanisms to drive enthalpic and entropic allostery, influencing protein affinity in the signaling cascade.
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Affiliation(s)
- Amrita Chakraborty
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
| | - Dibyamanjaree Samant
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
| | - Raju Sarkar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
| | - Satyam Sangeet
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
| | - Sangram Prusty
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
| | - Susmita Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, West Bengal 741246, India
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Li Z, Wei H, Hu D, Li X, Guo Y, Ding X, Guo H, Zhang L. Research Progress on the Structural and Functional Roles of hnRNPs in Muscle Development. Biomolecules 2023; 13:1434. [PMID: 37892116 PMCID: PMC10604023 DOI: 10.3390/biom13101434] [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: 09/04/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a superfamily of RNA-binding proteins consisting of more than 20 members. These proteins play a crucial role in various biological processes by regulating RNA splicing, transcription, and translation through their binding to RNA. In the context of muscle development and regeneration, hnRNPs are involved in a wide range of regulatory mechanisms, including alternative splicing, transcription regulation, miRNA regulation, and mRNA stability regulation. Recent studies have also suggested a potential association between hnRNPs and muscle-related diseases. In this report, we provide an overview of our current understanding of how hnRNPs regulate RNA metabolism and emphasize the significance of the key members of the hnRNP family in muscle development. Furthermore, we explore the relationship between the hnRNP family and muscle-related diseases.
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Affiliation(s)
| | | | | | | | | | | | | | - Linlin Zhang
- Key Laboratory of Animal Breeding and Healthy Livestock Farming, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300392, China; (Z.L.); (H.W.); (D.H.); (X.L.); (Y.G.); (X.D.); (H.G.)
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3
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Shenasa H, Bentley DL. Pre-mRNA splicing and its cotranscriptional connections. Trends Genet 2023; 39:672-685. [PMID: 37236814 PMCID: PMC10524715 DOI: 10.1016/j.tig.2023.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023]
Abstract
Transcription of eukaryotic genes by RNA polymerase II (Pol II) yields RNA precursors containing introns that must be spliced out and the flanking exons ligated together. Splicing is catalyzed by a dynamic ribonucleoprotein complex called the spliceosome. Recent evidence has shown that a large fraction of splicing occurs cotranscriptionally as the RNA chain is extruded from Pol II at speeds of up to 5 kb/minute. Splicing is more efficient when it is tethered to the transcription elongation complex, and this linkage permits functional coupling of splicing with transcription. We discuss recent progress that has uncovered a network of connections that link splicing to transcript elongation and other cotranscriptional RNA processing events.
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Affiliation(s)
- Hossein Shenasa
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - David L Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA.
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Choi S, Cho N, Kim KK. The implications of alternative pre-mRNA splicing in cell signal transduction. Exp Mol Med 2023; 55:755-766. [PMID: 37009804 PMCID: PMC10167241 DOI: 10.1038/s12276-023-00981-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/05/2023] [Accepted: 01/27/2023] [Indexed: 04/04/2023] Open
Abstract
Cells produce multiple mRNAs through alternative splicing, which ensures proteome diversity. Because most human genes undergo alternative splicing, key components of signal transduction pathways are no exception. Cells regulate various signal transduction pathways, including those associated with cell proliferation, development, differentiation, migration, and apoptosis. Since proteins produced through alternative splicing can exhibit diverse biological functions, splicing regulatory mechanisms affect all signal transduction pathways. Studies have demonstrated that proteins generated by the selective combination of exons encoding important domains can enhance or attenuate signal transduction and can stably and precisely regulate various signal transduction pathways. However, aberrant splicing regulation via genetic mutation or abnormal expression of splicing factors negatively affects signal transduction pathways and is associated with the onset and progression of various diseases, including cancer. In this review, we describe the effects of alternative splicing regulation on major signal transduction pathways and highlight the significance of alternative splicing.
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Affiliation(s)
- Sunkyung Choi
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Namjoon Cho
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Kee K Kim
- Department of Biochemistry, College of Natural Sciences, Chungnam National University, Daejeon, 34134, Republic of Korea.
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Li Q, Jiang Z, Ren S, Guo H, Song Z, Chen S, Gao X, Meng F, Zhu J, Liu L, Tong Q, Sun H, Sun Y, Pu J, Chang K, Liu J. SRSF5-Mediated Alternative Splicing of M Gene is Essential for Influenza A Virus Replication: A Host-Directed Target Against Influenza Virus. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203088. [PMID: 36257906 PMCID: PMC9731694 DOI: 10.1002/advs.202203088] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/21/2022] [Indexed: 05/29/2023]
Abstract
Splicing of influenza A virus (IAV) RNA is an essential process in the viral life cycle that involves the co-opting of host factors. Here, it is demonstrated that induction of host serine and arginine-rich splicing factor 5 (SRSF5) by IAV facilitated viral replication by enhancing viral M mRNA splicing. Mechanistically, SRSF5 with its RRM2 domain directly bounds M mRNA at conserved sites (M mRNA position 163, 709, and 712), and interacts with U1 small nuclear ribonucleoprotein (snRNP) to promote M mRNA splicing and M2 production. Mutations introduced to the three binding sites, without changing amino acid code, significantly attenuates virus replication and pathogenesis in vivo. Likewise, SRSF5 conditional knockout in the lung protects mice against lethal IAV challenge. Furthermore, anidulafungin, an approved antifungal drug, is identified as an inhibitor of SRSF5 that effectively blocks IAV replication in vitro and in vivo. In conclusion, SRSF5 as an activator of M mRNA splicing promotes IAV replication and is a host-derived antiviral target.
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Affiliation(s)
- Qiuchen Li
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Zhimin Jiang
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
- Chinese Academy of Sciences Key Laboratory of Infection and ImmunityInstitute of BiophysicsChinese Academy of SciencesBeijing100101China
| | - Shuning Ren
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Hui Guo
- Chinese Academy of Sciences Key Laboratory of Infection and ImmunityInstitute of BiophysicsChinese Academy of SciencesBeijing100101China
| | - Zhimin Song
- Chinese Academy of Sciences Key Laboratory of Infection and ImmunityInstitute of BiophysicsChinese Academy of SciencesBeijing100101China
| | - Saini Chen
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Xintao Gao
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Fanfeng Meng
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Junda Zhu
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Litao Liu
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Qi Tong
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Honglei Sun
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Yipeng Sun
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Juan Pu
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
| | - Kin‐Chow Chang
- School of Veterinary Medicine and ScienceUniversity of NottinghamSutton Bonington CampusSutton BoningtonLE12 5RDUK
| | - Jinhua Liu
- Key Laboratory for Prevention and Control of Avian Influenza and Other Major Poultry DiseasesKey Laboratory of Animal EpidemiologyMinistry of AgricultureCollege of Veterinary MedicineChina Agricultural UniversityBeijing100193China
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6
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Qiu J, Qu R, Lin M, Xu J, Zhu Q, Zhang Z, Sun J. Position-dependent effects of hnRNP A1/A2 in SMN1/2 exon7 splicing. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - GENE REGULATORY MECHANISMS 2022; 1865:194875. [DOI: 10.1016/j.bbagrm.2022.194875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/08/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022]
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7
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Hansen SR, White DS, Scalf M, Corrêa IR, Smith LM, Hoskins AA. Multi-step recognition of potential 5' splice sites by the Saccharomyces cerevisiae U1 snRNP. eLife 2022; 11:70534. [PMID: 35959885 PMCID: PMC9436412 DOI: 10.7554/elife.70534] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
In eukaryotes, splice sites define the introns of pre-mRNAs and must be recognized and excised with nucleotide precision by the spliceosome to make the correct mRNA product. In one of the earliest steps of spliceosome assembly, the U1 small nuclear ribonucleoprotein (snRNP) recognizes the 5' splice site (5' SS) through a combination of base pairing, protein-RNA contacts, and interactions with other splicing factors. Previous studies investigating the mechanisms of 5' SS recognition have largely been done in vivo or in cellular extracts where the U1/5' SS interaction is difficult to deconvolute from the effects of trans-acting factors or RNA structure. In this work we used colocalization single-molecule spectroscopy (CoSMoS) to elucidate the pathway of 5' SS selection by purified yeast U1 snRNP. We determined that U1 reversibly selects 5' SS in a sequence-dependent, two-step mechanism. A kinetic selection scheme enforces pairing at particular positions rather than overall duplex stability to achieve long-lived U1 binding. Our results provide a kinetic basis for how U1 may rapidly surveil nascent transcripts for 5' SS and preferentially accumulate at these sequences rather than on close cognates.
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Affiliation(s)
- Sarah R Hansen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States
| | - David S White
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | | | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - Aaron A Hoskins
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States
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8
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Müller L, Ptok J, Nisar A, Antemann J, Grothmann R, Hillebrand F, Brillen AL, Ritchie A, Theiss S, Schaal H. Modeling splicing outcome by combining 5'ss strength and splicing regulatory elements. Nucleic Acids Res 2022; 50:8834-8851. [PMID: 35947702 PMCID: PMC9410876 DOI: 10.1093/nar/gkac663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 06/23/2022] [Accepted: 07/27/2022] [Indexed: 12/24/2022] Open
Abstract
Correct pre-mRNA processing in higher eukaryotes vastly depends on splice site recognition. Beyond conserved 5'ss and 3'ss motifs, splicing regulatory elements (SREs) play a pivotal role in this recognition process. Here, we present in silico designed sequences with arbitrary a priori prescribed splicing regulatory HEXplorer properties that can be concatenated to arbitrary length without changing their regulatory properties. We experimentally validated in silico predictions in a massively parallel splicing reporter assay on more than 3000 sequences and exemplarily identified some SRE binding proteins. Aiming at a unified 'functional splice site strength' encompassing both U1 snRNA complementarity and impact from neighboring SREs, we developed a novel RNA-seq based 5'ss usage landscape, mapping the competition of pairs of high confidence 5'ss and neighboring exonic GT sites along HBond and HEXplorer score coordinate axes on human fibroblast and endothelium transcriptome datasets. These RNA-seq data served as basis for a logistic 5'ss usage prediction model, which greatly improved discrimination between strong but unused exonic GT sites and annotated highly used 5'ss. Our 5'ss usage landscape offers a unified view on 5'ss and SRE neighborhood impact on splice site recognition, and may contribute to improved mutation assessment in human genetics.
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Affiliation(s)
| | | | - Azlan Nisar
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany,Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, August-Schmidt-Ring 10, Recklinghausen 45665, Germany
| | - Jennifer Antemann
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Ramona Grothmann
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Frank Hillebrand
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Anna-Lena Brillen
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Anastasia Ritchie
- Institute of Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | | | - Heiner Schaal
- To whom correspondence should be addressed. Tel: +49 211 81 12393; Fax: +49 211 81 10856;
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9
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Pengelly RJ, Bakhtiar D, Borovská I, Královičová J, Vořechovský I. Exonic splicing code and protein binding sites for calcium. Nucleic Acids Res 2022; 50:5493-5512. [PMID: 35474482 PMCID: PMC9177970 DOI: 10.1093/nar/gkac270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 11/12/2022] Open
Abstract
Auxilliary splicing sequences in exons, known as enhancers (ESEs) and silencers (ESSs), have been subject to strong selection pressures at the RNA and protein level. The protein component of this splicing code is substantial, recently estimated at ∼50% of the total information within ESEs, but remains poorly understood. The ESE/ESS profiles were previously associated with the Irving-Williams (I-W) stability series for divalent metals, suggesting that the ESE/ESS evolution was shaped by metal binding sites. Here, we have examined splicing activities of exonic sequences that encode protein binding sites for Ca2+, a weak binder in the I-W affinity order. We found that predicted exon inclusion levels for the EF-hand motifs and for Ca2+-binding residues in nonEF-hand proteins were higher than for average exons. For canonical EF-hands, the increase was centred on the EF-hand chelation loop and, in particular, on Ca2+-coordinating residues, with a 1>12>3∼5>9 hierarchy in the 12-codon loop consensus and usage bias at codons 1 and 12. The same hierarchy but a lower increase was observed for noncanonical EF-hands, except for S100 proteins. EF-hand loops preferentially accumulated exon splits in two clusters, one located in their N-terminal halves and the other around codon 12. Using splicing assays and published crosslinking and immunoprecipitation data, we identify candidate trans-acting factors that preferentially bind conserved GA-rich motifs encoding negatively charged amino acids in the loops. Together, these data provide evidence for the high capacity of codons for Ca2+-coordinating residues to be retained in mature transcripts, facilitating their exon-level expansion during eukaryotic evolution.
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Affiliation(s)
- Reuben J Pengelly
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Dara Bakhtiar
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Ivana Borovská
- Slovak Academy of Sciences, Centre of Biosciences, 840 05 Bratislava, Slovak Republic
| | - Jana Královičová
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
- Slovak Academy of Sciences, Centre of Biosciences, 840 05 Bratislava, Slovak Republic
- Slovak Academy of Sciences, Institute of Zoology, 845 06 Bratislava, Slovak Republic
| | - Igor Vořechovský
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
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Saha K, Fernandez MM, Biswas T, Joseph S, Ghosh G. Discovery of a pre-mRNA structural scaffold as a contributor to the mammalian splicing code. Nucleic Acids Res 2021; 49:7103-7121. [PMID: 34161584 PMCID: PMC8266590 DOI: 10.1093/nar/gkab533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
The specific recognition of splice signals at or near exon-intron junctions is not explained by their weak conservation and instead is postulated to require a multitude of features embedded in the pre-mRNA strand. We explored the possibility of 3D structural scaffold of AdML-a model pre-mRNA substrate-guiding early spliceosomal components to the splice signal sequences. We find that mutations in the non-cognate splice signal sequences impede recruitment of early spliceosomal components due to disruption of the global structure of the pre-mRNA. We further find that the pre-mRNA segments potentially interacting with the early spliceosomal component U1 snRNP are distributed across the intron, that there is a spatial proximity of 5' and 3' splice sites within the pre-mRNA scaffold, and that an interplay exists between the structural scaffold and splicing regulatory elements in recruiting early spliceosomal components. These results suggest that early spliceosomal components can recognize a 3D structural scaffold beyond the short splice signal sequences, and that in our model pre-mRNA, this scaffold is formed across the intron involving the major splice signals. This provides a conceptual basis to analyze the contribution of recognizable 3D structural scaffolds to the splicing code across the mammalian transcriptome.
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Affiliation(s)
- Kaushik Saha
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Mike Minh Fernandez
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Tapan Biswas
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Simpson Joseph
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Gourisankar Ghosh
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
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Conboy JG. Unannotated splicing regulatory elements in deep intron space. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1656. [PMID: 33887804 DOI: 10.1002/wrna.1656] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/14/2021] [Accepted: 03/23/2021] [Indexed: 12/21/2022]
Abstract
Deep intron space harbors a diverse array of splicing regulatory elements that cooperate with better-known exon-proximal elements to enforce proper tissue-specific and development-specific pre-mRNA processing. Many deep intron elements have been highly conserved through vertebrate evolution, yet remain poorly annotated in the human genome. Recursive splicing exons (RS-exons) and intraexons promote noncanonical, multistep resplicing pathways in long introns, involving transient intermediate structures that are greatly underrepresented in RNA-seq datasets. Decoy splice sites and decoy exons act at a distance to inhibit splicing catalysis at annotated splice sites, with functional consequences such as exon skipping and intron retention. RNA:RNA bridges can juxtapose distant sequences within or across introns to activate deep intron splicing enhancers and silencers, to loop out exons to be skipped, or to select one member of a mutually exclusive set of exons. Similarly, protein bridges mediated by interactions among transcript-bound RNA binding proteins (RBPs) can modulate splicing outcomes. Experimental disruption of deep intron elements serving any of these functions can abrogate normal splicing, strongly suggesting that natural mutations of deep intron elements can do likewise to cause human disease. Understanding noncanonical splicing pathways and discovering deep intron regulatory signals, many of which map hundreds to many thousands of nucleotides from annotated splice junctions, is of great academic interest for basic scientists studying alternative splicing mechanisms. Hopefully, this knowledge coupled with increased analysis of deep intron sequences will also have important medical applications, as better interpretation of deep intron mutations may reveal new disease mechanisms and suggest new therapies. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- John G Conboy
- Lawrence Berkeley National Laboratory, Biological Systems and Engineering Division, Berkeley, California, USA
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12
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Zhang Y, Qian J, Gu C, Yang Y. Alternative splicing and cancer: a systematic review. Signal Transduct Target Ther 2021; 6:78. [PMID: 33623018 PMCID: PMC7902610 DOI: 10.1038/s41392-021-00486-7] [Citation(s) in RCA: 163] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 01/31/2023] Open
Abstract
The abnormal regulation of alternative splicing is usually accompanied by the occurrence and development of tumors, which would produce multiple different isoforms and diversify protein expression. The aim of the present study was to conduct a systematic review in order to describe the regulatory mechanisms of alternative splicing, as well as its functions in tumor cells, from proliferation and apoptosis to invasion and metastasis, and from angiogenesis to metabolism. The abnormal splicing events contributed to tumor progression as oncogenic drivers and/or bystander factors. The alterations in splicing factors detected in tumors and other mis-splicing events (i.e., long non-coding and circular RNAs) in tumorigenesis were also included. The findings of recent therapeutic approaches targeting splicing catalysis and splicing regulatory proteins to modulate pathogenically spliced events (including tumor-specific neo-antigens for cancer immunotherapy) were introduced. The emerging RNA-based strategies for the treatment of cancer with abnormally alternative splicing isoforms were also discussed. However, further studies are still required to address the association between alternative splicing and cancer in more detail.
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Affiliation(s)
- Yuanjiao Zhang
- The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jinjun Qian
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Chunyan Gu
- The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
| | - Ye Yang
- The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
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Abstract
U1 snRNP is one of the most abundant ribonucleoprotein (RNP) complexes in eukaryotic cells and is estimated to be approximately 1 million copies per cell. Apart from its canonical role in mRNA splicing, this complex has emerged as a key regulator of eukaryotic mRNA length via inhibition of mRNA 3'-end processing at numerous intronic polyadenylation sites, in a process that is also termed 'U1 snRNP telescripting'. Several reviews have extensively described the concept of U1 telescripting and subsequently highlighted its potential impacts in mRNA metabolism. Here, we review what is currently known regarding the underlying mechanisms of this important phenomenon and discuss open questions and future challenges.
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Affiliation(s)
- Yi Ran
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, China
| | - Yanhui Deng
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, China
| | - Chengguo Yao
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, China.,Department of Genetics and Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
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Hoser SM, Hoffmann A, Meindl A, Gamper M, Fallmann J, Bernhart SH, Müller L, Ploner M, Misslinger M, Kremser L, Lindner H, Geley S, Schaal H, Stadler PF, Huettenhofer A. Intronic tRNAs of mitochondrial origin regulate constitutive and alternative splicing. Genome Biol 2020; 21:299. [PMID: 33292386 PMCID: PMC7722341 DOI: 10.1186/s13059-020-02199-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 11/09/2020] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND The presence of nuclear mitochondrial DNA (numtDNA) has been reported within several nuclear genomes. Next to mitochondrial protein-coding genes, numtDNA sequences also encode for mitochondrial tRNA genes. However, the biological roles of numtDNA remain elusive. RESULTS Employing in silico analysis, we identify 281 mitochondrial tRNA homologs in the human genome, which we term nimtRNAs (nuclear intronic mitochondrial-derived tRNAs), being contained within introns of 76 nuclear host genes. Despite base changes in nimtRNAs when compared to their mtRNA homologs, a canonical tRNA cloverleaf structure is maintained. To address potential functions of intronic nimtRNAs, we insert them into introns of constitutive and alternative splicing reporters and demonstrate that nimtRNAs promote pre-mRNA splicing, dependent on the number and positioning of nimtRNA genes and splice site recognition efficiency. A mutational analysis reveals that the nimtRNA cloverleaf structure is required for the observed splicing increase. Utilizing a CRISPR/Cas9 approach, we show that a partial deletion of a single endogenous nimtRNALys within intron 28 of the PPFIBP1 gene decreases inclusion of the downstream-located exon 29 of the PPFIBP1 mRNA. By employing a pull-down approach followed by mass spectrometry, a 3'-splice site-associated protein network is identified, including KHDRBS1, which we show directly interacts with nimtRNATyr by an electrophoretic mobility shift assay. CONCLUSIONS We propose that nimtRNAs, along with associated protein factors, can act as a novel class of intronic splicing regulatory elements in the human genome by participating in the regulation of splicing.
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Affiliation(s)
- Simon M Hoser
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria.
| | - Anne Hoffmann
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Philipp-Rosenthal-Str. 27, 04103, Leipzig, Germany
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Andreas Meindl
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Maximilian Gamper
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Jörg Fallmann
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Stephan H Bernhart
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
| | - Lisa Müller
- Institute for Virology, Medical Faculty Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Melanie Ploner
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Matthias Misslinger
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Leopold Kremser
- Division of Clinical Biochemistry, Protein Micro-Analysis Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Herbert Lindner
- Division of Clinical Biochemistry, Protein Micro-Analysis Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Stephan Geley
- Institute of Pathophysiology, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria
| | - Heiner Schaal
- Institute for Virology, Medical Faculty Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, 04107, Leipzig, Germany
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, 04103, Leipzig, Germany
| | - Alexander Huettenhofer
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020, Innsbruck, Austria.
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