1
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Theil AF, Pines A, Kalayci T, Heredia‐Genestar JM, Raams A, Rietveld MH, Sridharan S, Tanis SEJ, Mulder KW, Büyükbabani N, Karaman B, Uyguner ZO, Kayserili H, Hoeijmakers JHJ, Lans H, Demmers JAA, Pothof J, Altunoglu U, El Ghalbzouri A, Vermeulen W. Trichothiodystrophy-associated MPLKIP maintains DBR1 levels for proper lariat debranching and ectodermal differentiation. EMBO Mol Med 2023; 15:e17973. [PMID: 37800682 PMCID: PMC10630875 DOI: 10.15252/emmm.202317973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/07/2023] Open
Abstract
The brittle hair syndrome Trichothiodystrophy (TTD) is characterized by variable clinical features, including photosensitivity, ichthyosis, growth retardation, microcephaly, intellectual disability, hypogonadism, and anaemia. TTD-associated mutations typically cause unstable mutant proteins involved in various steps of gene expression, severely reducing steady-state mutant protein levels. However, to date, no such link to instability of gene-expression factors for TTD-associated mutations in MPLKIP/TTDN1 has been established. Here, we present seven additional TTD individuals with MPLKIP mutations from five consanguineous families, with a newly identified MPLKIP variant in one family. By mass spectrometry-based interaction proteomics, we demonstrate that MPLKIP interacts with core splicing factors and the lariat debranching protein DBR1. MPLKIP-deficient primary fibroblasts have reduced steady-state DBR1 protein levels. Using Human Skin Equivalents (HSEs), we observed impaired keratinocyte differentiation associated with compromised splicing and eventually, an imbalanced proteome affecting skin development and, interestingly, also the immune system. Our data show that MPLKIP, through its DBR1 stabilizing role, is implicated in mRNA splicing, which is of particular importance in highly differentiated tissue.
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Affiliation(s)
- Arjan F Theil
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Alex Pines
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Tuğba Kalayci
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
| | | | - Anja Raams
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Marion H Rietveld
- Department of DermatologyLeiden University Medical Center (LUMC)LeidenThe Netherlands
| | - Sriram Sridharan
- Cancer Science Institute of SingaporeNational University of SingaporeSingaporeSingapore
| | - Sabine EJ Tanis
- Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life SciencesRadboud UniversityNijmegenThe Netherlands
| | - Klaas W Mulder
- Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life SciencesRadboud UniversityNijmegenThe Netherlands
| | - Nesimi Büyükbabani
- Department of Pathology, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University HospitalIstanbulTurkey
| | - Birsen Karaman
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Pediatric Basic Sciences, Child Health InstituteIstanbul UniversityIstanbulTurkey
| | - Zehra O Uyguner
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
| | - Hülya Kayserili
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University School of Medicine (KUSOM)IstanbulTurkey
| | - Jan HJ Hoeijmakers
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
- Institute for Genome Stability in Aging and Disease, CECAD ForschungszentrumUniversity Hospital of CologneKölnGermany
- Princess Máxima Center for Pediatric OncologyONCODE InstituteUtrechtThe Netherlands
| | - Hannes Lans
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | | | - Joris Pothof
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Umut Altunoglu
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University School of Medicine (KUSOM)IstanbulTurkey
| | | | - Wim Vermeulen
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
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2
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Jia M, Chen X, Shi X, Fang Y, Gu Y. Nuclear transport receptor KA120 regulates molecular condensation of MAC3 to coordinate plant immune activation. Cell Host Microbe 2023; 31:1685-1699.e7. [PMID: 37714161 DOI: 10.1016/j.chom.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/07/2023] [Accepted: 08/21/2023] [Indexed: 09/17/2023]
Abstract
The nucleocytoplasmic exchange is of fundamental importance to eukaryotic life and is mediated by karyopherins, a superfamily of nuclear transport receptors. However, the function and cargo spectrum of plant karyopherins are largely obscure. Here, we report proximity-labeling-based proteomic profiling of in vivo substrates of KA120, a karyopherin-β required for suppressing autoimmune induction in Arabidopsis. We identify multiple components of the MOS4-associated complex (MAC), a conserved splicing regulatory protein complex. Surprisingly, we find that KA120 does not affect the nucleocytoplasmic distribution of MAC proteins but rather prevents their protein condensation in the nucleus. Furthermore, we demonstrate that MAC condensation is robustly induced by pathogen infection, which is sufficient to activate defense gene expression, possibly by sequestrating negative immune regulators via phase transition. Our study reveals a noncanonical chaperoning activity of a plant karyopherin, which modulates the nuclear condensation of an evolutionarily conserved splicing regulatory complex to coordinate plant immune activation.
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Affiliation(s)
- Min Jia
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xuanyi Chen
- National Key Laboratory of Crop Improvement for Stress Tolerance and Production, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xuetao Shi
- Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yiling Fang
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Yangnan Gu
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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3
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Liu W, Xie H, Liu X, Xu S, Cheng S, Wang Z, Xie T, Zhang ZC, Han J. PQBP1 regulates striatum development through balancing striatal progenitor proliferation and differentiation. Cell Rep 2023; 42:112277. [PMID: 36943865 DOI: 10.1016/j.celrep.2023.112277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/16/2023] [Accepted: 03/03/2023] [Indexed: 03/23/2023] Open
Abstract
The balance between cell proliferation and differentiation is essential for maintaining the neural progenitor pool and brain development. Although the mechanisms underlying cell proliferation and differentiation at the transcriptional level have been studied intensively, post-transcriptional regulation of cell proliferation and differentiation remains largely unclear. Here, we show that deletion of the alternative splicing regulator PQBP1 in striatal progenitors results in defective striatal development due to impaired neurogenesis of spiny projection neurons (SPNs). Pqbp1-deficient striatal progenitors exhibit declined proliferation and increased differentiation, resulting in a reduced striatal progenitor pool. We further reveal that PQBP1 associates with components in splicing machinery. The alternative splicing profiles identify that PQBP1 promotes the exon 9 inclusion of Numb, a variant that mediates progenitor proliferation. These findings identify PQBP1 as a regulator in balancing striatal progenitor proliferation and differentiation and provide alternative insights into the pathogenic mechanisms underlying Renpenning syndrome.
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Affiliation(s)
- Wenhua Liu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Hao Xie
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Xian Liu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Shoujing Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Shanshan Cheng
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Zheng Wang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zi Chao Zhang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China.
| | - Junhai Han
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China; Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China.
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4
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Kuang Z, Ke J, Hong J, Zhu Z, Niu L. Structural assembly of the nucleic-acid-binding Thp3-Csn12-Sem1 complex functioning in mRNA splicing. Nucleic Acids Res 2022; 50:8882-8897. [PMID: 35904806 PMCID: PMC9410885 DOI: 10.1093/nar/gkac634] [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: 09/21/2021] [Revised: 06/26/2022] [Accepted: 07/21/2022] [Indexed: 12/02/2022] Open
Abstract
PCI domain proteins play important roles in post-transcriptional gene regulation. In the TREX-2 complex, PCI domain-containing Sac3 and Thp1 proteins and accessory Sem1 protein form a ternary complex required for mRNA nuclear export. In contrast, structurally related Thp3–Csn12–Sem1 complex mediates pre-mRNA splicing. In this study, we determined the structure of yeast Thp3186–470–Csn12–Sem1 ternary complex at 2.9 Å resolution. Both Thp3 and Csn12 structures have a typical PCI structural fold, characterized by a stack of α-helices capped by a C-terminal winged-helix (WH) domain. The overall structure of Thp3186–470–Csn12–Sem1 complex has an inverted V-shape with Thp3 and Csn12 forming the two sides. A fishhook-shaped Sem1 makes extensive contacts on Csn12 to stabilize its conformation. The overall structure of Thp3186–470–Csn12–Sem1 complex resembles the previously reported Sac3–Thp1–Sem1 complex, but also has significant structural differences. The C-terminal WH domains of Thp3 and Csn12 form a continuous surface to bind different forms of nucleic acids with micromolar affinity. Mutation of the basic residues in the WH domains of Thp3 and Csn12 affects nucleic acid binding in vitro and mRNA splicing in vivo. The Thp3–Csn12–Sem1 structure provides a foundation for further exploring the structural elements required for its specific recruitment to spliceosome for pre-mRNA splicing.
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Affiliation(s)
- Zhiling Kuang
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jiyuan Ke
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Northwest corner of Susong Rd & Guanhai Rd, Hefei, Anhui 230601, China
| | - Jiong Hong
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhongliang Zhu
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Liwen Niu
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Molecular and Cellular Biophysics, University of Science and Technology of China, Hefei, Anhui 230026, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
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5
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PQBP1: The Key to Intellectual Disability, Neurodegenerative Diseases, and Innate Immunity. Int J Mol Sci 2022; 23:ijms23116227. [PMID: 35682906 PMCID: PMC9180999 DOI: 10.3390/ijms23116227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022] Open
Abstract
The idea that a common pathology underlies various neurodegenerative diseases and dementias has attracted considerable attention in the basic and medical sciences. Polyglutamine binding protein-1 (PQBP1) was identified in 1998 after a molecule was predicted to bind to polyglutamine tract amino acid sequences, which are associated with a family of neurodegenerative disorders called polyglutamine diseases. Hereditary gene mutations of PQBP1 cause intellectual disability, whereas acquired loss of function of PQBP1 contributes to dementia pathology. PQBP1 functions in innate immune cells as an intracellular receptor that recognizes pathogens and neurodegenerative proteins. It is an intrinsically disordered protein that generates intracellular foci, similar to other neurodegenerative disease proteins such as TDP43, FUS, and hnRNPs. The knowledge accumulated over more than 20 years has given rise to a new concept that shifts in the equilibrium between physiological and pathological processes have their basis in the dysregulation of common protein structure-linked molecular mechanisms.
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6
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Jo SH, Park HJ, Lee A, Jung H, Park JM, Kwon SY, Kim HS, Lee HJ, Kim YS, Jung C, Cho HS. The Arabidopsis cyclophilin CYP18-1 facilitates PRP18 dephosphorylation and the splicing of introns retained under heat stress. THE PLANT CELL 2022; 34:2383-2403. [PMID: 35262729 PMCID: PMC9134067 DOI: 10.1093/plcell/koac084] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 03/05/2022] [Indexed: 05/13/2023]
Abstract
In plants, heat stress induces changes in alternative splicing, including intron retention; these events can rapidly alter proteins or downregulate protein activity, producing nonfunctional isoforms or inducing nonsense-mediated decay of messenger RNA (mRNA). Nuclear cyclophilins (CYPs) are accessory proteins in the spliceosome complexes of multicellular eukaryotes. However, whether plant CYPs are involved in pre-mRNA splicing remain unknown. Here, we found that Arabidopsis thaliana CYP18-1 is necessary for the efficient removal of introns that are retained in response to heat stress during germination. CYP18-1 interacts with Step II splicing factors (PRP18a, PRP22, and SWELLMAP1) and associates with the U2 and U5 small nuclear RNAs in response to heat stress. CYP18-1 binds to phospho-PRP18a, and increasing concentrations of CYP18-1 are associated with increasing dephosphorylation of PRP18a. Furthermore, interaction and protoplast transfection assays revealed that CYP18-1 and the PP2A-type phosphatase PP2A B'η co-regulate PRP18a dephosphorylation. RNA-seq and RT-qPCR analysis confirmed that CYP18-1 is essential for splicing introns that are retained under heat stress. Overall, we reveal the mechanism of action by which CYP18-1 activates the dephosphorylation of PRP18 and show that CYP18-1 is crucial for the efficient splicing of retained introns and rapid responses to heat stress in plants.
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Affiliation(s)
- Seung Hee Jo
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology,
Korea University of Science and Technology, Daejeon 34113, Korea
| | - Hyun Ji Park
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Areum Lee
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology,
Korea University of Science and Technology, Daejeon 34113, Korea
| | - Haemyeong Jung
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology,
Korea University of Science and Technology, Daejeon 34113, Korea
| | - Jeong Mee Park
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Suk-Yoon Kwon
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Hyun-Soon Kim
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Hyo-Jun Lee
- Plant Systems Engineering Research Center, Korea Research Institute of
Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Functional Genomics, KRIBB School of Bioscience, University
of Science and Technology, Daejeon 34113, Korea
| | - Youn-Sung Kim
- Department of Biotechnology, NongWoo
Bio, Anseong 17558, Korea
| | - Choonkyun Jung
- Department of International Agricultural Technology and Crop Biotechnology
Institute/Green Bio Science and Technology, Seoul National University,
Pyeongchang 25354, Korea
- Department of Agriculture, Forestry, and Bioresources and Integrated Major
in Global Smart Farm, College of Agriculture and Life Sciences, Seoul National
University, Seoul 08826, Korea
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7
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Lan W, Qiu Y, Xu Y, Liu Y, Miao Y. Ubiquitination and Ubiquitin-Like Modifications as Mediators of Alternative Pre-mRNA Splicing in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2022; 13:869870. [PMID: 35646014 PMCID: PMC9134077 DOI: 10.3389/fpls.2022.869870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Alternative splicing (AS) is a common post-transcriptional regulatory process in eukaryotes. AS has an irreplaceable role during plant development and in response to environmental stress as it evokes differential expression of downstream genes or splicing factors (e.g., serine/arginine-rich proteins). Numerous studies have reported that loss of AS capacity leads to defects in plant growth and development, and induction of stress-sensitive phenotypes. A role for post-translational modification (PTM) of AS components has emerged in recent years. These modifications are capable of regulating the activity, stability, localization, interaction, and folding of spliceosomal proteins in human cells and yeast, indicating that PTMs represent another layer of AS regulation. In this review, we summarize the recent reports concerning ubiquitin and ubiquitin-like modification of spliceosome components and analyze the relationship between spliceosome and the ubiquitin/26S proteasome pathway in plants. Based on the totality of the evidence presented, we further speculate on the roles of protein ubiquitination mediated AS in plant development and environmental response.
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8
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Idrissou M, Maréchal A. The PRP19 Ubiquitin Ligase, Standing at the Cross-Roads of mRNA Processing and Genome Stability. Cancers (Basel) 2022; 14:cancers14040878. [PMID: 35205626 PMCID: PMC8869861 DOI: 10.3390/cancers14040878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/01/2022] [Accepted: 02/04/2022] [Indexed: 12/07/2022] Open
Abstract
mRNA processing factors are increasingly being recognized as important regulators of genome stability. By preventing and resolving RNA:DNA hybrids that form co-transcriptionally, these proteins help avoid replication-transcription conflicts and thus contribute to genome stability through their normal function in RNA maturation. Some of these factors also have direct roles in the activation of the DNA damage response and in DNA repair. One of the most intriguing cases is that of PRP19, an evolutionarily conserved essential E3 ubiquitin ligase that promotes mRNA splicing, but also participates directly in ATR activation, double-strand break resection and mitosis. Here, we review historical and recent work on PRP19 and its associated proteins, highlighting their multifarious cellular functions as central regulators of spliceosome activity, R-loop homeostasis, DNA damage signaling and repair and cell division. Finally, we discuss open questions that are bound to shed further light on the functions of PRP19-containing complexes in both normal and cancer cells.
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Affiliation(s)
- Mouhamed Idrissou
- Faculty of Sciences, Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada;
- Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC J1H 5N3, Canada
| | - Alexandre Maréchal
- Faculty of Sciences, Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada;
- Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC J1H 5N3, Canada
- Correspondence:
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9
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Srivastava A, Ambrósio DL, Tasak M, Gosavi U, Günzl A. A distinct complex of PRP19-related and trypanosomatid-specific proteins is required for pre-mRNA splicing in trypanosomes. Nucleic Acids Res 2021; 49:12929-12942. [PMID: 34850936 PMCID: PMC8682746 DOI: 10.1093/nar/gkab1152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/30/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
The pre-mRNA splicing factor PRP19 is recruited into the spliceosome after forming the PRP19/CDC5L complex in humans and the Nineteen complex in yeast. Additionally, ‘PRP19-related’ proteins enter the spliceosome individually or in pre-assemblies that differ in these systems. The protistan family Trypanosomatidae, which harbors parasites such as Trypanosoma brucei, diverged early during evolution from opisthokonts. While introns are rare in these organisms, spliced leader trans splicing is an obligatory step in mRNA maturation. So far, ∼70 proteins have been identified as homologs of human and yeast splicing factors. Moreover, few proteins of unknown function have recurrently co-purified with splicing proteins. Here we silenced the gene of one of these proteins, termed PRC5, and found it to be essential for cell viability and pre-mRNA splicing. Purification of PRC5 combined with sucrose gradient sedimentation revealed a complex of PRC5 with a second trypanosomatid-specific protein, PRC3, and PRP19-related proteins SYF1, SYF3 and ISY1, which we named PRP19-related complex (PRC). Importantly, PRC and the previously described PRP19 complex are distinct from each other because PRC, unlike PRP19, co-precipitates U4 snRNA, which indicates that PRC enters the spliceosome prior to PRP19 and uncovers a unique pre-organization of these proteins in trypanosomes.
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Affiliation(s)
- Ankita Srivastava
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Daniela L Ambrósio
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030-6403, USA.,Departamento de Ciências da Biointeração, Universidade Federal da Bahia, Canela, Salvador, 40231-300, Brazil
| | - Monika Tasak
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Ujwala Gosavi
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Arthur Günzl
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
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10
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Liu X, Pan X, Chen D, Yin C, Peng J, Shi W, Qi L, Wang R, Zhao W, Zhang Z, Yang J, Peng YL. Prp19-associated splicing factor Cwf15 regulates fungal virulence and development in the rice blast fungus. Environ Microbiol 2021; 23:5901-5916. [PMID: 34056823 DOI: 10.1111/1462-2920.15616] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/29/2022]
Abstract
The splicing factor Cwf15 is an essential component of the Prp19-associated component of the spliceosome and regulates intron splicing in several model species, including yeasts and human cells. However, the roles of Cwf15 remain unexplored in plant pathogenic fungi. Here, we report that MoCWF15 in the rice blast fungus Magnaporthe oryzae is non-essential to viability and important to fungal virulence, growth and conidiation. MoCwf15 contains a putative nuclear localization signal (NLS) and is localized into the nucleus. The NLS sequence but not the predicted phosphorylation site or two sumoylation sites was essential for the biological functions of MoCwf15. Importantly, MoCwf15 physically interacted with the Prp19-associated splicing factors MoCwf4, MoSsa1 and MoCyp1, and negatively regulated protein accumulations of MoCyp1 and MoCwf4. Furthermore, with the deletion of MoCWF15, aberrant intron splicing occurred in near 400 genes, 20 of which were important to the fungal development and virulence. Taken together, MoCWF15 regulates fungal growth and infection-related development by modulating the intron splicing efficiency of a subset of genes in the rice blast fungus.
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Affiliation(s)
- Xinsen Liu
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xiao Pan
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Deng Chen
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Changfa Yin
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Junbo Peng
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Wei Shi
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Linlu Qi
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Ruijin Wang
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Wensheng Zhao
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China.,Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Ziding Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Jun Yang
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - You-Liang Peng
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
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11
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Kuhny M, Forbes LR, Çakan E, Vega-Loza A, Kostiuk V, Dinesh RK, Glauzy S, Stray-Pedersen A, Pezzi AE, Hanson IC, Vargas-Hernandez A, Xu ML, Coban-Akdemir ZH, Jhangiani SN, Muzny DM, Gibbs RA, Lupski JR, Chinn IK, Schatz DG, Orange JS, Meffre E. Disease-associated CTNNBL1 mutation impairs somatic hypermutation by decreasing nuclear AID. J Clin Invest 2021; 130:4411-4422. [PMID: 32484799 DOI: 10.1172/jci131297] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 05/13/2020] [Indexed: 01/02/2023] Open
Abstract
Patients with common variable immunodeficiency associated with autoimmune cytopenia (CVID+AIC) generate few isotype-switched B cells with severely decreased frequencies of somatic hypermutations (SHMs), but their underlying molecular defects remain poorly characterized. We identified a CVID+AIC patient who displays a rare homozygous missense M466V mutation in β-catenin-like protein 1 (CTNNBL1). Because CTNNBL1 binds activation-induced cytidine deaminase (AID) that catalyzes SHM, we tested AID interactions with the CTNNBL1 M466V variant. We found that the M466V mutation interfered with the association of CTNNBL1 with AID, resulting in decreased AID in the nuclei of patient EBV-transformed B cell lines and of CTNNBL1 466V/V Ramos B cells engineered to express only CTNNBL1 M466V using CRISPR/Cas9 technology. As a consequence, the scarce IgG+ memory B cells from the CTNNBL1 466V/V patient showed a low SHM frequency that averaged 6.7 mutations compared with about 18 mutations per clone in healthy-donor counterparts. In addition, CTNNBL1 466V/V Ramos B cells displayed a decreased incidence of SHM that was reduced by half compared with parental WT Ramos B cells, demonstrating that the CTNNBL1 M466V mutation is responsible for defective SHM induction. We conclude that CTNNBL1 plays an important role in regulating AID-dependent antibody diversification in humans.
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Affiliation(s)
- Marcel Kuhny
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lisa R Forbes
- Section of Pediatric Allergy, Immunology, and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,William T. Shearer Texas Children's Hospital Center for Human Immunobiology, Houston, Texas, USA
| | - Elif Çakan
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andrea Vega-Loza
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Valentyna Kostiuk
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ravi K Dinesh
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Salomé Glauzy
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Asbjorg Stray-Pedersen
- Baylor-Hopkins Center for Mendelian Genomics, Houston, Texas, USA.,Institute of Clinical Medicine and.,Norwegian National Unit for Newborn Screening, Department of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Ashley E Pezzi
- Department of Dermatology, Baylor College of Medicine, Houston, Texas, USA
| | - I Celine Hanson
- Section of Pediatric Allergy, Immunology, and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Alexander Vargas-Hernandez
- Section of Pediatric Allergy, Immunology, and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,William T. Shearer Texas Children's Hospital Center for Human Immunobiology, Houston, Texas, USA
| | - Mina LuQuing Xu
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Zeynep H Coban-Akdemir
- Baylor-Hopkins Center for Mendelian Genomics, Houston, Texas, USA.,Department of Molecular and Human Genetics and
| | - Shalini N Jhangiani
- Department of Molecular and Human Genetics and.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Donna M Muzny
- Department of Molecular and Human Genetics and.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Richard A Gibbs
- Baylor-Hopkins Center for Mendelian Genomics, Houston, Texas, USA.,Department of Molecular and Human Genetics and.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - James R Lupski
- Baylor-Hopkins Center for Mendelian Genomics, Houston, Texas, USA.,Department of Molecular and Human Genetics and.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Ivan K Chinn
- Section of Pediatric Allergy, Immunology, and Rheumatology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,William T. Shearer Texas Children's Hospital Center for Human Immunobiology, Houston, Texas, USA.,Baylor-Hopkins Center for Mendelian Genomics, Houston, Texas, USA
| | - David G Schatz
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jordan S Orange
- Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, New York, USA
| | - Eric Meffre
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA.,Section of Rheumatology, Allergy, and Clinical Immunology, Yale University School of Medicine, New Haven, Connecticut, USA
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12
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Townsend C, Leelaram MN, Agafonov DE, Dybkov O, Will CL, Bertram K, Urlaub H, Kastner B, Stark H, Lührmann R. Mechanism of protein-guided folding of the active site U2/U6 RNA during spliceosome activation. Science 2020; 370:science.abc3753. [PMID: 33243851 DOI: 10.1126/science.abc3753] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/23/2020] [Indexed: 01/02/2023]
Abstract
Spliceosome activation involves extensive protein and RNA rearrangements that lead to formation of a catalytically active U2/U6 RNA structure. At present, little is known about the assembly pathway of the latter and the mechanism whereby proteins aid its proper folding. Here, we report the cryo-electron microscopy structures of two human, activated spliceosome precursors (that is, pre-Bact complexes) at core resolutions of 3.9 and 4.2 angstroms. These structures elucidate the order of the numerous protein exchanges that occur during activation, the mutually exclusive interactions that ensure the correct order of ribonucleoprotein rearrangements needed to form the U2/U6 catalytic RNA, and the stepwise folding pathway of the latter. Structural comparisons with mature Bact complexes reveal the molecular mechanism whereby a conformational change in the scaffold protein PRP8 facilitates final three-dimensional folding of the U2/U6 catalytic RNA.
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Affiliation(s)
- Cole Townsend
- Department of Structural Dynamics, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Majety N Leelaram
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Dmitry E Agafonov
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Olexandr Dybkov
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Cindy L Will
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Karl Bertram
- Department of Structural Dynamics, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Germany
| | - Berthold Kastner
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Holger Stark
- Department of Structural Dynamics, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
| | - Reinhard Lührmann
- Cellular Biochemistry, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
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13
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Slane D, Lee CH, Kolb M, Dent C, Miao Y, Franz-Wachtel M, Lau S, Maček B, Balasubramanian S, Bayer M, Jürgens G. The integral spliceosomal component CWC15 is required for development in Arabidopsis. Sci Rep 2020; 10:13336. [PMID: 32770129 PMCID: PMC7415139 DOI: 10.1038/s41598-020-70324-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 07/27/2020] [Indexed: 01/01/2023] Open
Abstract
Efficient mRNA splicing is a prerequisite for protein biosynthesis and the eukaryotic splicing machinery is evolutionarily conserved among species of various phyla. At its catalytic core resides the activated splicing complex Bact consisting of the three small nuclear ribonucleoprotein complexes (snRNPs) U2, U5 and U6 and the so-called NineTeen complex (NTC) which is important for spliceosomal activation. CWC15 is an integral part of the NTC in humans and it is associated with the NTC in other species. Here we show the ubiquitous expression and developmental importance of the Arabidopsis ortholog of yeast CWC15. CWC15 associates with core components of the Arabidopsis NTC and its loss leads to inefficient splicing. Consistent with the central role of CWC15 in RNA splicing, cwc15 mutants are embryo lethal and additionally display strong defects in the female haploid phase. Interestingly, the haploid male gametophyte or pollen in Arabidopsis, on the other hand, can cope without functional CWC15, suggesting that developing pollen might be more tolerant to CWC15-mediated defects in splicing than either embryo or female gametophyte.
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Affiliation(s)
- Daniel Slane
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany
| | - Cameron H Lee
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Martina Kolb
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany
| | - Craig Dent
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, VIC, 3800, Australia
| | - Yingjing Miao
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
| | - Steffen Lau
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany
| | - Boris Maček
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
| | | | - Martin Bayer
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany
| | - Gerd Jürgens
- Max Planck Institute for Developmental Biology, Cell Biology, 72076, Tübingen, Germany.
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14
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Chu H, Perea W, Greenbaum NL. Role of the central junction in folding topology of the protein-free human U2-U6 snRNA complex. RNA (NEW YORK, N.Y.) 2020; 26:836-850. [PMID: 32220895 PMCID: PMC7297123 DOI: 10.1261/rna.073379.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/16/2020] [Indexed: 06/02/2023]
Abstract
U2 and U6 small nuclear (sn)RNAs are the only snRNAs directly implicated in catalyzing the splicing of pre-mRNA, but assembly and rearrangement steps prior to catalysis require numerous proteins. Previous studies have shown that the protein-free U2-U6 snRNA complex adopts two conformations in equilibrium, characterized by four and three helices surrounding a central junction. The four-helix conformer is strongly favored in the in vitro protein-free state, but the three-helix conformer predominates in spliceosomes. To analyze the role of the central junction in positioning elements forming the active site, we derived three-dimensional models of the two conformations from distances measured between fluorophores at selected locations in constructs representing the protein-free human U2-U6 snRNA complex by time-resolved fluorescence resonance energy transfer. Data describing four angles in the four-helix conformer suggest tetrahedral geometry; addition of Mg2+ results in shortening of the distances between neighboring helices, indicating compaction of the complex around the junction. In contrast, the three-helix conformer shows a closer approach between helices bearing critical elements, but the addition of Mg2+ widens the distance between them; thus in neither conformer are the critical helices positioned to favor the proposed triplex interaction. The presence of Mg2+ also enhances the fraction of the three-helix conformer, as does incubation with the Prp19-related protein RBM22, which has been implicated in the remodeling of the U2-U6 snRNA complex to render it catalytically active. These data suggest that although the central junction assumes a significant role in orienting helices, spliceosomal proteins and Mg2+ facilitate formation of the catalytically active conformer.
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Affiliation(s)
- Huong Chu
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
| | - William Perea
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
| | - Nancy L Greenbaum
- Department of Chemistry, Hunter College of the City University of New York, New York, New York 10065, USA
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
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15
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Liu X, Dou LX, Han J, Zhang ZC. The Renpenning syndrome-associated protein PQBP1 facilitates the nuclear import of splicing factor TXNL4A through the karyopherin β2 receptor. J Biol Chem 2020; 295:4093-4100. [PMID: 32041777 PMCID: PMC7105315 DOI: 10.1074/jbc.ra119.012214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/05/2020] [Indexed: 11/06/2022] Open
Abstract
Renpenning syndrome belongs to a group of X-linked intellectual disability disorders. The Renpenning syndrome-associated protein PQBP1 (polyglutamine-binding protein 1) is intrinsically disordered, associates with several splicing factors, and is involved in pre-mRNA splicing. PQBP1 uses its C-terminal YxxPxxVL motif for binding to the splicing factor TXNL4A (thioredoxin like 4A), but the biological function of this interaction has yet to be elucidated. In this study, using recombinant protein expression, in vitro binding assays, and immunofluorescence microscopy in HeLa cells, we found that a recently reported X-linked intellectual disability-associated missense mutation, resulting in the PQBP1-P244L variant, disrupts the interaction with TXNL4A. We further show that this interaction is critical for the subcellular location of TXNL4A. In combination with other PQBP1 variants lacking a functional nuclear localization signal required for recognition by the nuclear import receptor karyopherin β2, we demonstrate that PQBP1 facilitates the nuclear import of TXNL4A via a piggyback mechanism. These findings expand our understanding of the molecular basis of the PQBP1-TXNL4A interaction and of the etiology and pathogenesis of Renpenning syndrome and related disorders.
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Affiliation(s)
- Xian Liu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210096, China
| | - Lin-Xia Dou
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210096, China
| | - Junhai Han
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Zi Chao Zhang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.
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16
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Kastner B, Will CL, Stark H, Lührmann R. Structural Insights into Nuclear pre-mRNA Splicing in Higher Eukaryotes. Cold Spring Harb Perspect Biol 2019; 11:a032417. [PMID: 30765414 PMCID: PMC6824238 DOI: 10.1101/cshperspect.a032417] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The spliceosome is a highly complex, dynamic ribonucleoprotein molecular machine that undergoes numerous structural and compositional rearrangements that lead to the formation of its active site. Recent advances in cyroelectron microscopy (cryo-EM) have provided a plethora of near-atomic structural information about the inner workings of the spliceosome. Aided by previous biochemical, structural, and functional studies, cryo-EM has confirmed or provided a structural basis for most of the prevailing models of spliceosome function, but at the same time allowed novel insights into splicing catalysis and the intriguing dynamics of the spliceosome. The mechanism of pre-mRNA splicing is highly conserved between humans and yeast, but the compositional dynamics and ribonucleoprotein (RNP) remodeling of the human spliceosome are more complex. Here, we summarize recent advances in our understanding of the molecular architecture of the human spliceosome, highlighting differences between the human and yeast splicing machineries.
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Affiliation(s)
- Berthold Kastner
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Cindy L Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Holger Stark
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
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17
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Minocha R, Popova V, Kopytova D, Misiak D, Hüttelmaier S, Georgieva S, Sträßer K. Mud2 functions in transcription by recruiting the Prp19 and TREX complexes to transcribed genes. Nucleic Acids Res 2019; 46:9749-9763. [PMID: 30053068 PMCID: PMC6182176 DOI: 10.1093/nar/gky640] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 07/20/2018] [Indexed: 01/31/2023] Open
Abstract
The different steps of gene expression are intimately linked to coordinate and regulate this complex process. During transcription, numerous RNA-binding proteins are already loaded onto the nascent mRNA and package the mRNA into a messenger ribonucleoprotein particle (mRNP). These RNA-binding proteins are often also involved in other steps of gene expression than mRNA packaging. For example, TREX functions in transcription, mRNP packaging and nuclear mRNA export. Previously, we showed that the Prp19 splicing complex (Prp19C) is needed for efficient transcription as well as TREX occupancy at transcribed genes. Here, we show that the splicing factor Mud2 interacts with Prp19C and is needed for Prp19C occupancy at transcribed genes in Saccharomyces cerevisiae. Interestingly, Mud2 is not only recruited to intron-containing but also to intronless genes indicating a role in transcription. Indeed, we show for the first time that Mud2 functions in transcription. Furthermore, these functions of Mud2 are likely evolutionarily conserved as Mud2 is also recruited to an intronless gene and interacts with Prp19C in Drosophila melanogaster. Taken together, we classify Mud2 as a novel transcription factor that is necessary for the recruitment of mRNA-binding proteins to the transcription machinery. Thus, Mud2 is a multifunctional protein important for transcription, splicing and most likely also mRNP packaging.
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Affiliation(s)
- Rashmi Minocha
- Institute of Biochemistry, Justus Liebig University, Giessen 35392, Germany
| | - Varvara Popova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Daria Kopytova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Danny Misiak
- Institute of Molecular Medicine, Martin-Luther-University Halle Wittenberg, Halle 06120, Germany
| | - Stefan Hüttelmaier
- Institute of Molecular Medicine, Martin-Luther-University Halle Wittenberg, Halle 06120, Germany
| | - Sofia Georgieva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Katja Sträßer
- Institute of Biochemistry, Justus Liebig University, Giessen 35392, Germany
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18
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Carbonell C, Ulsamer A, Vivori C, Papasaikas P, Böttcher R, Joaquin M, Miñana B, Tejedor JR, de Nadal E, Valcárcel J, Posas F. Functional Network Analysis Reveals the Relevance of SKIIP in the Regulation of Alternative Splicing by p38 SAPK. Cell Rep 2019; 27:847-859.e6. [PMID: 30995481 PMCID: PMC6484779 DOI: 10.1016/j.celrep.2019.03.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 02/21/2019] [Accepted: 03/15/2019] [Indexed: 01/03/2023] Open
Abstract
Alternative splicing is a prevalent mechanism of gene regulation that is modulated in response to a wide range of extracellular stimuli. Stress-activated protein kinases (SAPKs) play a key role in controlling several steps of mRNA biogenesis. Here, we show that osmostress has an impact on the regulation of alternative splicing (AS), which is partly mediated through the action of p38 SAPK. Splicing network analysis revealed a functional connection between p38 and the spliceosome component SKIIP, whose depletion abolished a significant fraction of p38-mediated AS changes. Importantly, p38 interacted with and directly phosphorylated SKIIP, thereby altering its activity. SKIIP phosphorylation regulated AS of GADD45α, the upstream activator of the p38 pathway, uncovering a negative feedback loop involving AS regulation. Our data reveal mechanisms and targets of SAPK function in stress adaptation through the regulation of AS.
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Affiliation(s)
- Caterina Carbonell
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Arnau Ulsamer
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Claudia Vivori
- Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Panagiotis Papasaikas
- Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - René Böttcher
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Manel Joaquin
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Belén Miñana
- Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Juan Ramón Tejedor
- Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Eulàlia de Nadal
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain.
| | - Juan Valcárcel
- Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Dr. Aiguader 88, 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain.
| | - Francesc Posas
- Cell Signaling Research Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain.
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19
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Zahr HC, Jaalouk DE. Exploring the Crosstalk Between LMNA and Splicing Machinery Gene Mutations in Dilated Cardiomyopathy. Front Genet 2018; 9:231. [PMID: 30050558 PMCID: PMC6052891 DOI: 10.3389/fgene.2018.00231] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 06/11/2018] [Indexed: 12/18/2022] Open
Abstract
Mutations in the LMNA gene, which encodes for the nuclear lamina proteins lamins A and C, are responsible for a diverse group of diseases known as laminopathies. One type of laminopathy is Dilated Cardiomyopathy (DCM), a heart muscle disease characterized by dilation of the left ventricle and impaired systolic function, often leading to heart failure and sudden cardiac death. LMNA is the second most commonly mutated gene in DCM. In addition to LMNA, mutations in more than 60 genes have been associated with DCM. The DCM-associated genes encode a variety of proteins including transcription factors, cytoskeletal, Ca2+-regulating, ion-channel, desmosomal, sarcomeric, and nuclear-membrane proteins. Another important category among DCM-causing genes emerged upon the identification of DCM-causing mutations in RNA binding motif protein 20 (RBM20), an alternative splicing factor that is chiefly expressed in the heart. In addition to RBM20, several essential splicing factors were validated, by employing mouse knock out models, to be embryonically lethal due to aberrant cardiogenesis. Furthermore, heart-specific deletion of some of these splicing factors was found to result in aberrant splicing of their targets and DCM development. In addition to splicing alterations, advances in next generation sequencing highlighted the association between splice-site mutations in several genes and DCM. This review summarizes LMNA mutations and splicing alterations in DCM and discusses how the interaction between LMNA and splicing regulators could possibly explain DCM disease mechanisms.
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Affiliation(s)
| | - Diana E. Jaalouk
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
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20
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Tanaka H, Kondo K, Chen X, Homma H, Tagawa K, Kerever A, Aoki S, Saito T, Saido T, Muramatsu SI, Fujita K, Okazawa H. The intellectual disability gene PQBP1 rescues Alzheimer's disease pathology. Mol Psychiatry 2018; 23:2090-2110. [PMID: 30283027 PMCID: PMC6250680 DOI: 10.1038/s41380-018-0253-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/09/2018] [Accepted: 09/06/2018] [Indexed: 12/11/2022]
Abstract
Early-phase pathologies of Alzheimer's disease (AD) are attracting much attention after clinical trials of drugs designed to remove beta-amyloid (Aβ) aggregates failed to recover memory and cognitive function in symptomatic AD patients. Here, we show that phosphorylation of serine/arginine repetitive matrix 2 (SRRM2) at Ser1068, which is observed in the brains of early phase AD mouse models and postmortem end-stage AD patients, prevents its nuclear translocation by inhibiting interaction with T-complex protein subunit α. SRRM2 deficiency in neurons destabilized polyglutamine binding protein 1 (PQBP1), a causative gene for intellectual disability (ID), greatly affecting the splicing patterns of synapse-related genes, as demonstrated in a newly generated PQBP1-conditional knockout model. PQBP1 and SRRM2 were downregulated in cortical neurons of human AD patients and mouse AD models, and the AAV-PQBP1 vector recovered RNA splicing, the synapse phenotype, and the cognitive decline in the two mouse models. Finally, the kinases responsible for the phosphorylation of SRRM2 at Ser1068 were identified as ERK1/2 (MAPK3/1). These results collectively reveal a new aspect of AD pathology in which a phosphorylation signal affecting RNA splicing and synapse integrity precedes the formation of extracellular Aβ aggregates and may progress in parallel with tau phosphorylation.
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Affiliation(s)
- Hikari Tanaka
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Kanoh Kondo
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Xigui Chen
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Hidenori Homma
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Kazuhiko Tagawa
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Aurelian Kerever
- 0000 0004 1762 2738grid.258269.2Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 Japan
| | - Shigeki Aoki
- 0000 0004 1762 2738grid.258269.2Department of Radiology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 Japan
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, Center for Brain Science, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, Center for Brain Science, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - Shin-ichi Muramatsu
- 0000000123090000grid.410804.9Department of Neurology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0496 Japan
| | - Kyota Fujita
- 0000 0001 1014 9130grid.265073.5Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 Japan
| | - Hitoshi Okazawa
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan. .,Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
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21
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Hildebrandt A, Alanis-Lobato G, Voigt A, Zarnack K, Andrade-Navarro MA, Beli P, König J. Interaction profiling of RNA-binding ubiquitin ligases reveals a link between posttranscriptional regulation and the ubiquitin system. Sci Rep 2017; 7:16582. [PMID: 29185492 PMCID: PMC5707401 DOI: 10.1038/s41598-017-16695-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 09/14/2017] [Indexed: 11/09/2022] Open
Abstract
RNA-binding ubiquitin ligases (RBULs) have the potential to link RNA-mediated mechanisms to protein ubiquitylation. Despite this, the cellular functions, substrates and interaction partners of most RBULs remain poorly characterized. Affinity purification (AP) combined with quantitative mass spectrometry (MS)-based proteomics is a powerful approach for analyzing protein functions. Mapping the physiological interaction partners of RNA-binding proteins has been hampered by their intrinsic properties, in particular the existence of low-complexity regions, which are prone to engage in non-physiological interactions. Here, we used an adapted AP approach to identify the interaction partners of human RBULs harboring different RNA-binding domains. To increase the likelihood of recovering physiological interactions, we combined control and bait-expressing cells prior to lysis. In this setup, only stable interactions that were originally present in the cell will be identified. We exploit gene function similarity between the bait proteins and their interactors to benchmark our approach in its ability to recover physiological interactions. We reveal that RBULs engage in stable interactions with RNA-binding proteins involved in different steps of RNA metabolism as well as with components of the ubiquitin conjugation machinery and ubiquitin-binding proteins. Our results thus demonstrate their capacity to link posttranscriptional regulation with the ubiquitin system.
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Affiliation(s)
- Andrea Hildebrandt
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany
| | - Gregorio Alanis-Lobato
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany.,Faculty of Biology, Johannes Gutenberg University, Gresemundweg 2, 55128, Mainz, Germany
| | - Andrea Voigt
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany
| | - Miguel A Andrade-Navarro
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany.,Faculty of Biology, Johannes Gutenberg University, Gresemundweg 2, 55128, Mainz, Germany
| | - Petra Beli
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany.
| | - Julian König
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128, Mainz, Germany.
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22
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Pozzi B, Bragado L, Will CL, Mammi P, Risso G, Urlaub H, Lührmann R, Srebrow A. SUMO conjugation to spliceosomal proteins is required for efficient pre-mRNA splicing. Nucleic Acids Res 2017; 45:6729-6745. [PMID: 28379520 PMCID: PMC5499870 DOI: 10.1093/nar/gkx213] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 03/24/2017] [Indexed: 12/26/2022] Open
Abstract
Pre-mRNA splicing is catalyzed by the spliceosome, a multi-megadalton ribonucleoprotein machine. Previous work from our laboratory revealed the splicing factor SRSF1 as a regulator of the SUMO pathway, leading us to explore a connection between this pathway and the splicing machinery. We show here that addition of a recombinant SUMO-protease decreases the efficiency of pre-mRNA splicing in vitro. By mass spectrometry analysis of anti-SUMO immunoprecipitated proteins obtained from purified splicing complexes formed along the splicing reaction, we identified spliceosome-associated SUMO substrates. After corroborating SUMOylation of Prp3 in cultured cells, we defined Lys 289 and Lys 559 as bona fide SUMO attachment sites within this spliceosomal protein. We further demonstrated that a Prp3 SUMOylation-deficient mutant while still capable of interacting with U4/U6 snRNP components, is unable to co-precipitate U2 and U5 snRNA and the spliceosomal proteins U2-SF3a120 and U5-Snu114. This SUMOylation-deficient mutant fails to restore the splicing of different pre-mRNAs to the levels achieved by the wild type protein, when transfected into Prp3-depleted cultured cells. This mutant also shows a diminished recruitment to active spliceosomes, compared to the wild type protein. These findings indicate that SUMO conjugation plays a role during the splicing process and suggest the involvement of Prp3 SUMOylation in U4/U6•U5 tri-snRNP formation and/or recruitment.
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Affiliation(s)
- Berta Pozzi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Laureano Bragado
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Cindy L Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Pablo Mammi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Guillermo Risso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Anabella Srebrow
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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23
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Henning LM, Santos KF, Sticht J, Jehle S, Lee CT, Wittwer M, Urlaub H, Stelzl U, Wahl MC, Freund C. A new role for FBP21 as regulator of Brr2 helicase activity. Nucleic Acids Res 2017; 45:7922-7937. [PMID: 28838205 PMCID: PMC5570060 DOI: 10.1093/nar/gkx535] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/19/2017] [Indexed: 02/01/2023] Open
Abstract
Splicing of eukaryotic pre-mRNA is carried out by the spliceosome, which assembles stepwise on each splicing substrate. This requires the concerted action of snRNPs and non-snRNP accessory proteins, the functions of which are often not well understood. Of special interest are B complex factors that enter the spliceosome prior to catalytic activation and may alter splicing kinetics and splice site selection. One of these proteins is FBP21, for which we identified several spliceosomal binding partners in a yeast-two-hybrid screen, among them the RNA helicase Brr2. Biochemical and biophysical analyses revealed that an intrinsically disordered region of FBP21 binds to an extended surface of the C-terminal Sec63 unit of Brr2. Additional contacts in the C-terminal helicase cassette are required for allosteric inhibition of Brr2 helicase activity. Furthermore, the direct interaction between FBP21 and the U4/U6 di-snRNA was found to reduce the pool of unwound U4/U6 di-snRNA. Our results suggest FBP21 as a novel key player in the regulation of Brr2.
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Affiliation(s)
- Lisa M Henning
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany
| | - Karine F Santos
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Takustr. 6, Berlin 14195, Germany
| | - Jana Sticht
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany.,BioSupraMol Gerätezentrum, Freie Universität Berlin, Takustr. 3, Berlin 14195, Germany
| | - Stefanie Jehle
- Max-Planck-Insitute for Molecular Genetics, Ihnestraße 63-74, Berlin 14195, Germany
| | - Chung-Tien Lee
- Max-Planck-Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry Group, Am Fassberg 11, Göttingen 37077, Germany.,University Medical Center Goettingen, Bioanalytics, Department of Clinical Chemistry, Robert Koch Strasse 40, Göttingen 37075, Germany
| | - Malte Wittwer
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany
| | - Henning Urlaub
- Max-Planck-Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry Group, Am Fassberg 11, Göttingen 37077, Germany.,University Medical Center Goettingen, Bioanalytics, Department of Clinical Chemistry, Robert Koch Strasse 40, Göttingen 37075, Germany
| | - Ulrich Stelzl
- Max-Planck-Insitute for Molecular Genetics, Ihnestraße 63-74, Berlin 14195, Germany
| | - Markus C Wahl
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Takustr. 6, Berlin 14195, Germany.,Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Albert- Einstein-Straße 15, Berlin 12489, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, Berlin 14195, Germany
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24
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Zhang Y, Li Y, Liang X, Zhu Z, Sun H, He H, Min J, Liao S, Liu Y. Crystal structure of the WD40 domain of human PRPF19. Biochem Biophys Res Commun 2017; 493:1250-1253. [PMID: 28962858 DOI: 10.1016/j.bbrc.2017.09.145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022]
Abstract
Human Pre-mRNA Processing factor 19 (hPRPF19) is an important component in human spliceosome machinery. hPRPF19 contains a WD40 repeats domain at its C-terminus, which is also conserved in yeast. Here we determined the crystal structure of the C-terminal WD40 repeat domain of hPRPF19 by X-ray crystallography. Our structural analysis revealed some significantly different structure features between the human and yeast Prp19 WD40 repeat domain. However, there are also conserved clusters of residues at the bottom surface of the fourth and the fifth WD40 repeats, which provides the important implication for the conserved Prp19 proteins in both human and yeast.
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Affiliation(s)
- Yuzhe Zhang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China; Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada; Yunnan Provincial Key Laboratory of Entomological Biopharmaceutical R&D, Dali University, Dali 671000, PR China
| | - Yue Li
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, PR China
| | - Xiao Liang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Zhongliang Zhu
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, PR China
| | - Hongbin Sun
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Academy of Sciences of China, Hefei 230031, PR China
| | - Hao He
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Jinrong Min
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China; Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Shanhui Liao
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, PR China.
| | - Yanli Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China; Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
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25
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Sidarovich A, Will CL, Anokhina MM, Ceballos J, Sievers S, Agafonov DE, Samatov T, Bao P, Kastner B, Urlaub H, Waldmann H, Lührmann R. Identification of a small molecule inhibitor that stalls splicing at an early step of spliceosome activation. eLife 2017; 6. [PMID: 28300534 PMCID: PMC5354520 DOI: 10.7554/elife.23533] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/26/2017] [Indexed: 11/13/2022] Open
Abstract
Small molecule inhibitors of pre-mRNA splicing are important tools for identifying new spliceosome assembly intermediates, allowing a finer dissection of spliceosome dynamics and function. Here, we identified a small molecule that inhibits human pre-mRNA splicing at an intermediate stage during conversion of pre-catalytic spliceosomal B complexes into activated Bact complexes. Characterization of the stalled complexes (designated B028) revealed that U4/U6 snRNP proteins are released during activation before the U6 Lsm and B-specific proteins, and before recruitment and/or stable incorporation of Prp19/CDC5L complex and other Bact complex proteins. The U2/U6 RNA network in B028 complexes differs from that of the Bact complex, consistent with the idea that the catalytic RNA core forms stepwise during the B to Bact transition and is likely stabilized by the Prp19/CDC5L complex and related proteins. Taken together, our data provide new insights into the RNP rearrangements and extensive exchange of proteins that occurs during spliceosome activation. DOI:http://dx.doi.org/10.7554/eLife.23533.001
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Affiliation(s)
- Anzhalika Sidarovich
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Cindy L Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Maria M Anokhina
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Javier Ceballos
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sonja Sievers
- Compound Management and Screening Center, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Dmitry E Agafonov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Timur Samatov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Penghui Bao
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Berthold Kastner
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytics Group, Institute for Clinical Chemistry Göttingen, University Medical Center, Göttingen, Germany
| | - Herbert Waldmann
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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26
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Agafonov DE, van Santen M, Kastner B, Dube P, Will CL, Urlaub H, Lührmann R. ATPγS stalls splicing after B complex formation but prior to spliceosome activation. RNA (NEW YORK, N.Y.) 2016; 22:1329-1337. [PMID: 27411562 PMCID: PMC4986889 DOI: 10.1261/rna.057810.116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 06/28/2016] [Indexed: 06/06/2023]
Abstract
The ATP analog ATPγS inhibits pre-mRNA splicing in vitro, but there have been conflicting reports as to which step of splicing is inhibited by this small molecule and its inhibitory mechanism remains unclear. Here we have dissected the effect of ATPγS on pre-mRNA splicing in vitro. Addition of ATPγS to splicing extracts depleted of ATP inhibited both catalytic steps of splicing. At ATPγS concentrations ≥0.5 mM, precatalytic B complexes accumulate, demonstrating a block prior to or during the spliceosome activation stage. Affinity purification of the ATPγS-stalled B complexes (B(ATPγS)) and subsequent characterization of their abundant protein components by 2D gel electrophoresis revealed that B(ATPγS) complexes are compositionally more homogeneous than B complexes previously isolated in the presence of ATP. In particular, they contain little or no Prp19/CDC5L complex proteins, indicating that these proteins are recruited after assembly of the precatalytic spliceosome. Under the electron microscope, B(ATPγS) complexes exhibit a morphology highly similar to B complexes, indicating that the ATPγS-induced block in the transformation of the B to B(act) complex is not due to a major structural defect. Likely mechanisms whereby ATPγS blocks spliceosome assembly at the activation stage, including inhibition of the RNA helicase Brr2, are discussed. Given their more homogeneous composition, B complexes stalled by ATPγS may prove highly useful for both functional and structural analyses of the precatalytic spliceosome and its conversion into an activated B(act) spliceosomal complex.
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Affiliation(s)
- Dmitry E Agafonov
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Marieke van Santen
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Berthold Kastner
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Prakash Dube
- 3D Electron Cryomicroscopy Group, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Cindy L Will
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, D-37075 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
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27
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Mizuguchi M, Obita T, Kajiyama A, Kozakai Y, Nakai T, Nabeshima Y, Okazawa H. Allosteric modulation of the binding affinity between PQBP1 and the spliceosomal protein U5-15kD. FEBS Lett 2016; 590:2221-31. [PMID: 27314904 DOI: 10.1002/1873-3468.12256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/30/2016] [Accepted: 06/08/2016] [Indexed: 01/31/2023]
Abstract
Polyglutamine tract-binding protein 1 (PQBP1) is an intrinsically disordered protein composed of a small folded WW domain and a long disordered region. PQBP1 binds to spliceosomal proteins WBP11 and U5-15kD through its N-terminal WW domain and C-terminal region, respectively. Here, we reveal that the binding between PQBP1 and WBP11 reduces the binding affinity between PQBP1 and U5-15kD. Our results suggest that the interaction between PQBP1 and WBP11 negatively modulates the U5-15kD binding of PQBP1 by an allosteric mechanism.
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Affiliation(s)
- Mineyuki Mizuguchi
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan.,Graduate School of Innovative Life Science, University of Toyama, Japan
| | - Takayuki Obita
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan
| | - Asagi Kajiyama
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan
| | - Yuki Kozakai
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan
| | - Tsuyoshi Nakai
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan
| | - Yuko Nabeshima
- Faculty of Pharmaceutical Sciences, University of Toyama, Japan
| | - Hitoshi Okazawa
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Bunkyo-ku, Japan
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28
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De I, Schmitzová J, Pena V. The organization and contribution of helicases to RNA splicing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:259-74. [PMID: 26874649 DOI: 10.1002/wrna.1331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 12/27/2022]
Abstract
Splicing is an essential step of gene expression. It occurs in two consecutive chemical reactions catalyzed by a large protein-RNA complex named the spliceosome. Assembled on the pre-mRNA substrate from five small nuclear proteins, the spliceosome acts as a protein-controlled ribozyme to catalyze the two reactions and finally dissociates into its components, which are re-used for a new round of splicing. Upon following this cyclic pathway, the spliceosome undergoes numerous intermediate stages that differ in composition as well as in their internal RNA-RNA and RNA-protein contacts. The driving forces and control mechanisms of these remodeling processes are provided by specific molecular motors called RNA helicases. While eight spliceosomal helicases are present in all organisms, higher eukaryotes contain five additional ones potentially required to drive a more intricate splicing pathway and link it to an RNA metabolism of increasing complexity. Spliceosomal helicases exhibit a notable structural diversity in their accessory domains and overall architecture, in accordance with the diversity of their task-specific functions. This review summarizes structure-function knowledge about all spliceosomal helicases, including the latter five, which traditionally are treated separately from the conserved ones. The implications of the structural characteristics of helicases for their functions, as well as for their structural communication within the multi-subunits environment of the spliceosome, are pointed out.
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Affiliation(s)
- Inessa De
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Jana Schmitzová
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Vladimir Pena
- Macromolecular Crystallography Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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29
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CryoEM structures of two spliceosomal complexes: starter and dessert at the spliceosome feast. Curr Opin Struct Biol 2016; 36:48-57. [PMID: 26803803 PMCID: PMC4830896 DOI: 10.1016/j.sbi.2015.12.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/21/2015] [Indexed: 12/31/2022]
Abstract
Recent advances in cryoEM are revolutionizing our understanding of how molecular machines function. The structure of Saccharomyces cerevisiae U4/U6.U5 tri-snRNP has been revealed. The structure of Schizosaccharomyces pombe U2.U6.U5 spliceosomal complex has been revealed. These structures greatly advanced our understanding of the mechanism of pre-mRNA splicing.
The spliceosome is formed on pre-mRNA substrates from five small nuclear ribonucleoprotein particles (U1, U2, U4/U6 and U5 snRNPs), and numerous non-snRNP factors. Saccharomyces cerevisiae U4/U6.U5 tri-snRNP comprises U5 snRNA, U4/U6 snRNA duplex and approximately 30 proteins and represents a substantial part of the spliceosome before activation. Schizosaccharomyces pombe U2.U6.U5 spliceosomal complex is a post-catalytic intron lariat spliceosome containing U2 and U5 snRNPs, NTC (nineteen complex), NTC-related proteins (NTR), U6 snRNA, and an RNA intron lariat. Two recent papers describe near-complete atomic structures of these complexes based on cryoEM single-particle analysis. The U4/U6.U5 tri-snRNP structure provides crucial insight into the activation mechanism of the spliceosome. The U2.U6.U5 complex reveals the striking architecture of NTC and NTR and important features of the group II intron-like catalytic RNA core remaining after spliced mRNA is released. These two structures greatly advance our understanding of the mechanism of pre-mRNA splicing.
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30
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Ahn JW, Sik Jin K, Francis Son H, Ho Chang J, Kim KJ. Small angle X-ray scattering studies of CTNNBL1 dimerization and CTNNBL1/CDC5L complex. Sci Rep 2015; 5:14251. [PMID: 26381213 PMCID: PMC4585563 DOI: 10.1038/srep14251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 08/21/2015] [Indexed: 01/13/2023] Open
Abstract
The hPrp19/CDC5L complex is a non-snRNP spliceosome complex that plays a key role in the spliceosome activation during pre-mRNA splicing, and CTNNBL1 and CDC5L are essential components of the complex. In this study, to investigate the oligomeric state of CTNNBL1 in solution, we performed small angle X-ray scattering experiments in various concentrations of NaCl. We observed that CTNNBL1 existed as a dimer in physiological NaCl concentrations. Site-directed mutagenesis experiment of CTNNBL1 confirmed that N-terminal capping region and the first four ARM repeats are important for dimerization of the protein. We also found that the positively-charged NLS3-containing region (residues 197-235) of CDC5L bound to the negatively-charged patch of CTNNBL1 and that the CTNNBL1/CDC5L complex formed a heterotetramer consisting of one CTNNBL1 dimer and one CDC5L dimer. Moreover, reconstruction of 3D models of CTNNBL1/CDC5L complexes containing CTNNBL1 and three different truncated forms of CDC5L showed that the CDC5L(141-196) region and the CDC5L(236-377) region were positioned at the top of the N-terminal capping region and at the bottom of ARM VII of CTNNBL1, respectively.
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Affiliation(s)
- Jae-Woo Ahn
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Jigok-ro 80, Pohang, Kyungbuk 790-784, Korea
| | - Hyeoncheol Francis Son
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea
| | - Jeong Ho Chang
- Department of Biology, Teachers College, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea
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hPso4/hPrp19: a critical component of DNA repair and DNA damage checkpoint complexes. Oncogene 2015; 35:2279-86. [PMID: 26364595 DOI: 10.1038/onc.2015.321] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/16/2015] [Accepted: 07/19/2015] [Indexed: 12/15/2022]
Abstract
Genome integrity is vital to cellular homeostasis and its forfeiture is linked to deleterious consequences-cancer, immunodeficiency, genetic disorders and premature aging. The human ubiquitin ligase Pso4/Prp19 has emerged as a critical component of multiple DNA damage response (DDR) signaling networks. It not only senses DNA damage, binds double-stranded DNA in a sequence-independent manner, facilitates processing of damaged DNA, promotes DNA end joining, regulates replication protein A (RPA2) phosphorylation and ubiquitination at damaged DNA, but also regulates RNA splicing and mitotic spindle formation in its integral capacity as a scaffold for a multimeric core complex. Accordingly, by virtue of its regulatory and structural interactions with key proteins critical for genome integrity-DNA double-strand break (DSB) repair, DNA interstrand crosslink repair, repair of stalled replication forks and DNA end joining-it fills a unique niche in restoring genomic integrity after multiple types of DNA damage and thus has a vital role in maintaining chromatin integrity and cellular functions. These properties may underlie its ability to thwart replicative senescence and, not surprisingly, have been linked to the self-renewal and colony-forming ability of murine hematopoietic stem cells. This review highlights recent advances in hPso4 research that provides a fascinating glimpse into the pleiotropic activities of a ubiquitously expressed multifunctional E3 ubiquitin ligase.
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Ito H, Fujita K, Tagawa K, Chen X, Homma H, Sasabe T, Shimizu J, Shimizu S, Tamura T, Muramatsu SI, Okazawa H. HMGB1 facilitates repair of mitochondrial DNA damage and extends the lifespan of mutant ataxin-1 knock-in mice. EMBO Mol Med 2015; 7:78-101. [PMID: 25510912 PMCID: PMC4309669 DOI: 10.15252/emmm.201404392] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Mutant ataxin-1 (Atxn1), which causes spinocerebellar ataxia type 1 (SCA1), binds to and impairs the function of high-mobility group box 1 (HMGB1), a crucial nuclear protein that regulates DNA architectural changes essential for DNA damage repair and transcription. In this study, we established that transgenic or virus vector-mediated complementation with HMGB1 ameliorates motor dysfunction and prolongs lifespan in mutant Atxn1 knock-in (Atxn1-KI) mice. We identified mitochondrial DNA damage repair by HMGB1 as a novel molecular basis for this effect, in addition to the mechanisms already associated with HMGB1 function, such as nuclear DNA damage repair and nuclear transcription. The dysfunction and the improvement of mitochondrial DNA damage repair functions are tightly associated with the exacerbation and rescue, respectively, of symptoms, supporting the involvement of mitochondrial DNA quality control by HMGB1 in SCA1 pathology. Moreover, we show that the rescue of Purkinje cell dendrites and dendritic spines by HMGB1 could be downstream effects. Although extracellular HMGB1 triggers inflammation mediated by Toll-like receptor and receptor for advanced glycation end products, upregulation of intracellular HMGB1 does not induce such side effects. Thus, viral delivery of HMGB1 is a candidate approach by which to modify the disease progression of SCA1 even after the onset.
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Affiliation(s)
- Hikaru Ito
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Kyota Fujita
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Kazuhiko Tagawa
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Xigui Chen
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Hidenori Homma
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Toshikazu Sasabe
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Jun Shimizu
- Department of Neurology, The University of Tokyo, Bunkyo-ku Tokyo, Japan
| | - Shigeomi Shimizu
- Department of Pathological Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Takuya Tamura
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
| | - Shin-ichi Muramatsu
- Department of Neurology, Jichi Medical University, Shimotsuke Tochigi, Japan
| | - Hitoshi Okazawa
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan Center for Brain Integration Research, Tokyo Medical and Dental University, Bunkyo-ku Tokyo, Japan
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van Maldegem F, Maslen S, Johnson CM, Chandra A, Ganesh K, Skehel M, Rada C. CTNNBL1 facilitates the association of CWC15 with CDC5L and is required to maintain the abundance of the Prp19 spliceosomal complex. Nucleic Acids Res 2015; 43:7058-69. [PMID: 26130721 PMCID: PMC4538830 DOI: 10.1093/nar/gkv643] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 06/09/2015] [Indexed: 12/16/2022] Open
Abstract
In order to catalyse the splicing of messenger RNA, multiple proteins and RNA components associate and dissociate in a dynamic highly choreographed process. The Prp19 complex is a conserved essential part of the splicing machinery thought to facilitate the conformational changes the spliceosome undergoes during catalysis. Dynamic protein interactions often involve highly disordered regions that are difficult to study by structural methods. Using amine crosslinking and hydrogen-deuterium exchange coupled to mass spectrometry, we describe the architecture of the Prp19 sub-complex that contains CTNNBL1. Deficiency in CTNNBL1 leads to delayed initiation of cell division and embryonic lethality. Here we show that in vitro CTNNBL1 enhances the association of CWC15 and CDC5L, both core Prp19 complex proteins and identify an overlap in the region of CDC5L that binds either CTNNBL1 or CWC15 suggesting the two proteins might exchange places in the complex. Furthermore, in vivo, CTNNBL1 is required to maintain normal levels of the Prp19 complex and to facilitate the interaction of CWC15 with CDC5L. Our results identify a chaperone function for CTNNBL1 within the essential Prp19 complex, a function required to maintain the integrity of the complex and to support efficient splicing.
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Affiliation(s)
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | | | - Anita Chandra
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Karuna Ganesh
- Department of Medicine and Cancer Biology & Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Cristina Rada
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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Makarova OV, Makarov EM. The 35S U5 snRNP Is Generated from the Activated Spliceosome during In vitro Splicing. PLoS One 2015; 10:e0128430. [PMID: 26020933 PMCID: PMC4447412 DOI: 10.1371/journal.pone.0128430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/27/2015] [Indexed: 11/18/2022] Open
Abstract
Primary gene transcripts of eukaryotes contain introns, which are removed during processing by splicing machinery. Biochemical studies In vitro have identified a specific pathway in which introns are recognised and spliced out. This occurs by progressive formation of spliceosomal complexes designated as E, A, B, and C. The composition and structure of these spliceosomal conformations have been characterised in many detail. In contrast, transitions between the complexes and the intermediates of these reactions are currently less clear. We have previously isolated a novel 35S U5 snRNP from HeLa nuclear extracts. The protein composition of this particle differed from the canonical 20S U5 snRNPs but was remarkably similar to the activated B* spliceosomes. Based on this observation we have proposed a hypothesis that 35S U5 snRNPs represent a dissociation product of the spliceosome after both transesterification reactions are completed. Here we provide experimental evidence that 35S U5 snRNPs are generated from the activated B* spliceosomes during In vitro splicing.
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Affiliation(s)
- Olga V. Makarova
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen D-, Germany
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Evgeny M. Makarov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen D-, Germany
- Division of Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
- * E-mail:
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35
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Ito H, Shiwaku H, Yoshida C, Homma H, Luo H, Chen X, Fujita K, Musante L, Fischer U, Frints SGM, Romano C, Ikeuchi Y, Shimamura T, Imoto S, Miyano S, Muramatsu SI, Kawauchi T, Hoshino M, Sudol M, Arumughan A, Wanker EE, Rich T, Schwartz C, Matsuzaki F, Bonni A, Kalscheuer VM, Okazawa H. In utero gene therapy rescues microcephaly caused by Pqbp1-hypofunction in neural stem progenitor cells. Mol Psychiatry 2015; 20:459-71. [PMID: 25070536 PMCID: PMC4378255 DOI: 10.1038/mp.2014.69] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 04/10/2014] [Accepted: 05/12/2014] [Indexed: 12/21/2022]
Abstract
Human mutations in PQBP1, a molecule involved in transcription and splicing, result in a reduced but architecturally normal brain. Examination of a conditional Pqbp1-knockout (cKO) mouse with microcephaly failed to reveal either abnormal centrosomes or mitotic spindles, increased neurogenesis from the neural stem progenitor cell (NSPC) pool or increased cell death in vivo. Instead, we observed an increase in the length of the cell cycle, particularly for the M phase in NSPCs. Corresponding to the developmental expression of Pqbp1, the stem cell pool in vivo was decreased at E10 and remained at a low level during neurogenesis (E15) in Pqbp1-cKO mice. The expression profiles of NSPCs derived from the cKO mouse revealed significant changes in gene groups that control the M phase, including anaphase-promoting complex genes, via aberrant transcription and RNA splicing. Exogenous Apc4, a hub protein in the network of affected genes, recovered the cell cycle, proliferation, and cell phenotypes of NSPCs caused by Pqbp1-cKO. These data reveal a mechanism of brain size control based on the simple reduction of the NSPC pool by cell cycle time elongation. Finally, we demonstrated that in utero gene therapy for Pqbp1-cKO mice by intraperitoneal injection of the PQBP1-AAV vector at E10 successfully rescued microcephaly with preserved cortical structures and improved behavioral abnormalities in Pqbp1-cKO mice, opening a new strategy for treating this intractable developmental disorder.
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Affiliation(s)
- H Ito
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - H Shiwaku
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - C Yoshida
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - H Homma
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - H Luo
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - X Chen
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - K Fujita
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - L Musante
- Department of Human Molecular Genetics, Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | - U Fischer
- Department of Human Molecular Genetics, Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | - S G M Frints
- Department of Clinical Genetics, University Hospital azM Maastricht, Maastricht, The Netherlands,School for Oncology and Developmental Biology, GROW, Maastricht University, Maastricht, The Netherlands
| | - C Romano
- Unità Operativa Complessa di Pediatria e Genetica Medica, IRCCS Associazione Oasi Maria Santissima, Troina (Enna), Italy
| | - Y Ikeuchi
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, MO, USA,Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - T Shimamura
- Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - S Imoto
- Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - S Miyano
- Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - S-i Muramatsu
- Department of Neurology, Jichi Medical University, Tochigi, Japan
| | - T Kawauchi
- Department of Anatomy, Keio University School of Medicine, Tokyo, Japan
| | - M Hoshino
- Department of Biochemistry and Cellular Biology, National Center for Neurology and Psychiatry, Tokyo, Japan
| | - M Sudol
- Laboratory of Signal Transduction and Proteomic Profiling, Weis Center for Research, Geisinger Clinic, Danville, PA, USA
| | - A Arumughan
- Department of Neurogenetics, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - E E Wanker
- Department of Neurogenetics, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - T Rich
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - C Schwartz
- JC Self Research Institute of Human Genetics, Greenwood Genetic Center, Greenwood, SC, USA
| | - F Matsuzaki
- Laboratory for Cell Asymmetry, Center for Developmental Biology, RIKEN, Chuo-ku, Kobe, Japan
| | - A Bonni
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, MO, USA,Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - V M Kalscheuer
- Department of Human Molecular Genetics, Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | - H Okazawa
- Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan,Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan. E-mail:
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36
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Absmeier E, Rosenberger L, Apelt L, Becke C, Santos KF, Stelzl U, Wahl MC. A noncanonical PWI domain in the N-terminal helicase-associated region of the spliceosomal Brr2 protein. ACTA ACUST UNITED AC 2015; 71:762-71. [DOI: 10.1107/s1399004715001005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/16/2015] [Indexed: 11/10/2022]
Abstract
The spliceosomal RNA helicase Brr2 is required for the assembly of a catalytically active spliceosome on a messenger RNA precursor. Brr2 exhibits an unusual organization with tandem helicase units, each comprising dual RecA-like domains and a Sec63 homology unit, preceded by a more than 400-residue N-terminal helicase-associated region. Whereas recent crystal structures have provided insights into the molecular architecture and regulation of the Brr2 helicase region, little is known about the structural organization and function of its N-terminal part. Here, a near-atomic resolution crystal structure of a PWI-like domain that resides in the N-terminal region ofChaetomium thermophilumBrr2 is presented. CD spectroscopic studies suggested that this domain is conserved in the yeast and human Brr2 orthologues. Although canonical PWI domains act as low-specificity nucleic acid-binding domains, no significant affinity of the unusual PWI domain of Brr2 for a broad spectrum of DNAs and RNAs was detected in band-shift assays. Consistently, theC. thermophilumBrr2 PWI-like domain, in the conformation seen in the present crystal structure, lacks an expanded positively charged surface patch as observed in at least one canonical, nucleic acid-binding PWI domain. Instead, in a comprehensive yeast two-hybrid screen against human spliceosomal proteins, fragments of the N-terminal region of human Brr2 were found to interact with several other spliceosomal proteins. At least one of these interactions, with the Prp19 complex protein SPF27, depended on the presence of the PWI-like domain. The results suggest that the N-terminal region of Brr2 serves as a versatile protein–protein interaction platform in the spliceosome and that some interactions require or are reinforced by the PWI-like domain.
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37
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Ambrósio DL, Badjatia N, Günzl A. The spliceosomal PRP19 complex of trypanosomes. Mol Microbiol 2015; 95:885-901. [PMID: 25524563 DOI: 10.1111/mmi.12910] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2014] [Indexed: 02/05/2023]
Abstract
In trypanosomes, mRNAs are processed by spliced leader (SL) trans splicing, in which a capped SL, derived from SL RNA, is spliced onto the 5' end of each mRNA. This process is mediated by the spliceosome, a large and dynamic RNA-protein machinery consisting of small nuclear ribonucleoproteins (snRNPs) and non-snRNP proteins. Due to early evolutionary divergence, the amino acid sequences of trypanosome splicing factors exhibit limited similarity to those of their eukaryotic orthologs making their bioinformatic identification challenging. Most of the ~ 60 protein components that have been characterized thus far are snRNP proteins because, in contrast to individual snRNPs, purification of intact spliceosomes has not been achieved yet. Here, we characterize the non-snRNP PRP19 complex of Trypanosoma brucei. We identified a complex that contained the core subunits PRP19, CDC5, PRL1, and SPF27, as well as PRP17, SKIP and PPIL1. Three of these proteins were newly annotated. The PRP19 complex was associated primarily with the activated spliceosome and, accordingly, SPF27 silencing blocked the first splicing step. Interestingly, SPF27 silencing caused an accumulation of SL RNA with a hypomethylated cap that closely resembled the defect observed previously upon depletion of the cyclin-dependent kinase CRK9, indicating that both proteins may function in spliceosome activation.
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Affiliation(s)
- Daniela L Ambrósio
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT, 06030-6403, USA
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38
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The RNA helicase Aquarius exhibits structural adaptations mediating its recruitment to spliceosomes. Nat Struct Mol Biol 2015; 22:138-44. [PMID: 25599396 DOI: 10.1038/nsmb.2951] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/11/2014] [Indexed: 11/08/2022]
Abstract
Aquarius is a multifunctional putative RNA helicase that binds precursor-mRNA introns at a defined position. Here we report the crystal structure of human Aquarius, revealing a central RNA helicase core and several unique accessory domains, including an ARM-repeat domain. We show that Aquarius is integrated into spliceosomes as part of a pentameric intron-binding complex (IBC) that, together with the ARM domain, cross-links to U2 snRNP proteins within activated spliceosomes; this suggests that the latter aid in positioning Aquarius on the intron. Aquarius's ARM domain is essential for IBC formation, thus indicating that it has a key protein-protein-scaffolding role. Finally, we provide evidence that Aquarius is required for efficient precursor-mRNA splicing in vitro. Our findings highlight the remarkable structural adaptations of a helicase to achieve position-specific recruitment to a ribonucleoprotein complex and reveal a new building block of the human spliceosome.
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39
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Functional Splicing Network Reveals Extensive Regulatory Potential of the Core Spliceosomal Machinery. Mol Cell 2015; 57:7-22. [DOI: 10.1016/j.molcel.2014.10.030] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 09/24/2014] [Accepted: 10/31/2014] [Indexed: 12/12/2022]
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40
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Wee CD, Havens MA, Jodelka FM, Hastings ML. Targeting SR proteins improves SMN expression in spinal muscular atrophy cells. PLoS One 2014; 9:e115205. [PMID: 25506695 PMCID: PMC4266657 DOI: 10.1371/journal.pone.0115205] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 11/19/2014] [Indexed: 12/19/2022] Open
Abstract
Spinal muscular atrophy (SMA) is one of the most common inherited causes of pediatric mortality. SMA is caused by deletions or mutations in the survival of motor neuron 1 (SMN1) gene, which results in SMN protein deficiency. Humans have a centromeric copy of the survival of motor neuron gene, SMN2, which is nearly identical to SMN1. However, SMN2 cannot compensate for the loss of SMN1 because SMN2 has a single-nucleotide difference in exon 7, which negatively affects splicing of the exon. As a result, most mRNA produced from SMN2 lacks exon 7. SMN2 mRNA lacking exon 7 encodes a truncated protein with reduced functionality. Improving SMN2 exon 7 inclusion is a goal of many SMA therapeutic strategies. The identification of regulators of exon 7 inclusion may provide additional therapeutic targets or improve the design of existing strategies. Although a number of regulators of exon 7 inclusion have been identified, the function of most splicing proteins in exon 7 inclusion is unknown. Here, we test the role of SR proteins and hnRNP proteins in SMN2 exon 7 inclusion. Knockdown and overexpression studies reveal that SRSF1, SRSF2, SRSF3, SRSF4, SRSF5, SRSF6, SRSF7, SRSF11, hnRNPA1/B1 and hnRNP U can inhibit exon 7 inclusion. Depletion of two of the most potent inhibitors of exon 7 inclusion, SRSF2 or SRSF3, in cell lines derived from SMA patients, increased SMN2 exon 7 inclusion and SMN protein. Our results identify novel regulators of SMN2 exon 7 inclusion, revealing potential targets for SMA therapeutics.
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Affiliation(s)
- Claribel D. Wee
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Mallory A. Havens
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Francine M. Jodelka
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Michelle L. Hastings
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
- * E-mail:
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41
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Sundaramoorthy S, Vázquez-Novelle MD, Lekomtsev S, Howell M, Petronczki M. Functional genomics identifies a requirement of pre-mRNA splicing factors for sister chromatid cohesion. EMBO J 2014; 33:2623-42. [PMID: 25257310 PMCID: PMC4282572 DOI: 10.15252/embj.201488244] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 08/03/2014] [Accepted: 08/18/2014] [Indexed: 12/20/2022] Open
Abstract
Sister chromatid cohesion mediated by the cohesin complex is essential for chromosome segregation during cell division. Using functional genomic screening, we identify a set of 26 pre-mRNA splicing factors that are required for sister chromatid cohesion in human cells. Loss of spliceosome subunits increases the dissociation rate of cohesin from chromatin and abrogates cohesion after DNA replication, ultimately causing mitotic catastrophe. Depletion of splicing factors causes defective processing of the pre-mRNA encoding sororin, a factor required for the stable association of cohesin with chromatin, and an associated reduction of sororin protein level. Expression of an intronless version of sororin and depletion of the cohesin release protein WAPL suppress the cohesion defect in cells lacking splicing factors. We propose that spliceosome components contribute to sister chromatid cohesion and mitotic chromosome segregation through splicing of sororin pre-mRNA. Our results highlight the loss of cohesion as an early cellular consequence of compromised splicing. This may have clinical implications because SF3B1, a splicing factor that we identify to be essential for cohesion, is recurrently mutated in chronic lymphocytic leukaemia.
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Affiliation(s)
- Sriramkumar Sundaramoorthy
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - María Dolores Vázquez-Novelle
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - Sergey Lekomtsev
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - Michael Howell
- High-throughput Screening Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Mark Petronczki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
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42
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van der Lelij P, Stocsits RR, Ladurner R, Petzold G, Kreidl E, Koch B, Schmitz J, Neumann B, Ellenberg J, Peters JM. SNW1 enables sister chromatid cohesion by mediating the splicing of sororin and APC2 pre-mRNAs. EMBO J 2014; 33:2643-58. [PMID: 25257309 DOI: 10.15252/embj.201488202] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Although splicing is essential for the expression of most eukaryotic genes, inactivation of splicing factors causes specific defects in mitosis. The molecular cause of this defect is unknown. Here, we show that the spliceosome subunits SNW1 and PRPF8 are essential for sister chromatid cohesion in human cells. A transcriptome-wide analysis revealed that SNW1 or PRPF8 depletion affects the splicing of specific introns in a subset of pre-mRNAs, including pre-mRNAs encoding the cohesion protein sororin and the APC/C subunit APC2. SNW1 depletion causes cohesion defects predominantly by reducing sororin levels, which causes destabilisation of cohesin on DNA. SNW1 depletion also reduces APC/C activity and contributes to cohesion defects indirectly by delaying mitosis and causing "cohesion fatigue". Simultaneous expression of sororin and APC2 from intron-less cDNAs restores cohesion in SNW1-depleted cells. These results indicate that the spliceosome is required for mitosis because it enables expression of genes essential for cohesion. Our transcriptome-wide identification of retained introns in SNW1- and PRPF8-depleted cells may help to understand the aetiology of diseases associated with splicing defects, such as retinosa pigmentosum and cancer.
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Affiliation(s)
| | | | - Rene Ladurner
- IMP Research Institute of Molecular Pathology, Vienna, Austria
| | - Georg Petzold
- IMP Research Institute of Molecular Pathology, Vienna, Austria
| | - Emanuel Kreidl
- IMP Research Institute of Molecular Pathology, Vienna, Austria
| | - Birgit Koch
- IMP Research Institute of Molecular Pathology, Vienna, Austria EMBL Heidelberg, Heidelberg, Germany
| | - Julia Schmitz
- IMP Research Institute of Molecular Pathology, Vienna, Austria
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43
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Iwasaki Y, Thomsen GH. The splicing factor PQBP1 regulates mesodermal and neural development through FGF signaling. Development 2014; 141:3740-51. [PMID: 25209246 DOI: 10.1242/dev.106658] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Alternative splicing of pre-mRNAs is an important means of regulating developmental processes, yet the molecular mechanisms governing alternative splicing in embryonic contexts are just beginning to emerge. Polyglutamine-binding protein 1 (PQBP1) is an RNA-splicing factor that, when mutated, in humans causes Renpenning syndrome, an X-linked intellectual disability disease characterized by severe cognitive impairment, but also by physical defects that suggest PQBP1 has broader functions in embryonic development. Here, we reveal essential roles for PQBP1 and a binding partner, WBP11, in early development of Xenopus embryos. Both genes are expressed in the nascent mesoderm and neurectoderm, and morpholino knockdown of either causes defects in differentiation and morphogenesis of the mesoderm and neural plate. At the molecular level, knockdown of PQBP1 in Xenopus animal cap explants inhibits target gene induction by FGF but not by BMP, Nodal or Wnt ligands, and knockdown of either PQBP1 or WBP11 in embryos inhibits expression of fgf4 and FGF4-responsive cdx4 genes. Furthermore, PQBP1 knockdown changes the alternative splicing of FGF receptor-2 (FGFR2) transcripts, altering the incorporation of cassette exons that generate receptor variants (FGFR2 IIIb or IIIc) with different ligand specificities. Our findings may inform studies into the mechanisms underlying Renpenning syndrome.
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Affiliation(s)
- Yasuno Iwasaki
- Department of Biochemistry and Cell Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY 11794-5215, USA
| | - Gerald H Thomsen
- Department of Biochemistry and Cell Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY 11794-5215, USA
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44
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Valdés J, Nozaki T, Sato E, Chiba Y, Nakada-Tsukui K, Villegas-Sepúlveda N, Winkler R, Azuara-Liceaga E, Mendoza-Figueroa MS, Watanabe N, Santos HJ, Saito-Nakano Y, Galindo-Rosales JM. Proteomic analysis of Entamoeba histolytica in vivo assembled pre-mRNA splicing complexes. J Proteomics 2014; 111:30-45. [PMID: 25109466 DOI: 10.1016/j.jprot.2014.07.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/27/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED The genome of the human intestinal parasite Entamoeba histolytica contains nearly 3000 introns and bioinformatic predictions indicate that major and minor spliceosomes occur in Entamoeba. However, except for the U2-, U4-, U5- and U6 snRNAs, no other splicing factor has been cloned and characterized. Here, we HA-tagged cloned the snRNP component U1A and assessed its expression and nuclear localization. Because the snRNP-free U1A form interacts with polyadenylate-binding protein, HA-U1A immunoprecipitates could identify early and late splicing complexes. Avoiding Entamoeba's endonucleases and ensuring the precipitation of RNA-binding proteins, parasite cultures were UV cross-linked prior to nuclear fraction immunoprecipitations with HA antibodies, and precipitates were subjected to tandem mass spectrometry (MS/MS) analyses. To discriminate their nuclear roles (chromatin-, co-transcriptional-, splicing-related), MS/MS analyses were carried out with proteins eluted with MS2-GST-sepharose from nuclear extracts of an MS2 aptamer-tagged Rabx13 intron amoeba transformant. Thus, we probed thirty-six Entamoeba proteins corresponding to 32 cognate splicing-specific factors, including 13 DExH/D helicases required for all stages of splicing, and 12 different splicing-related helicases were identified also. Furthermore 50 additional proteins, possibly involved in co-transcriptional processes were identified, revealing the complexity of co-transcriptional splicing in Entamoeba. Some of these later factors were not previously found in splicing complex analyses. BIOLOGICAL SIGNIFICANCE Numerous facts about the splicing of the nearly 3000 introns of the Entamoeba genome have not been unraveled, particularly the splicing factors and their activities. Considering that many of such introns are located in metabolic genes, the knowledge of the splicing cues has the potential to be used to attack or control the parasite. We have found numerous new splicing-related factors which could have therapeutic benefit. We also detected all the DExH/A RNA helicases involved in splicing and splicing proofreading control. Still, Entamoeba is very inefficient in splicing fidelity, thus we may have found a possible model system to study these processes.
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Affiliation(s)
- Jesús Valdés
- Departament of Biochemistry, CINVESTAV, México D.F., Mexico.
| | - Tomoyoshi Nozaki
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Emi Sato
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yoko Chiba
- University of Tsukuba, Graduate School of Life and Environmental Sciences, Tsukuba, Japan
| | - Kumiko Nakada-Tsukui
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | | | - Robert Winkler
- Department of Biotechnology and Biochemistry, CINVESTAV Unidad Irapuato, Irapuato, Guanajuato, Mexico
| | | | | | - Natsuki Watanabe
- University of Tsukuba, Graduate School of Life and Environmental Sciences, Tsukuba, Japan
| | - Herbert J Santos
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan; University of Tsukuba, Graduate School of Life and Environmental Sciences, Tsukuba, Japan; Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City, Philippines
| | - Yumiko Saito-Nakano
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
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45
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Benjamin AB, Zhou X, Isaac O, Zhao H, Song Y, Chi X, Sun B, Hao L, Zhang L, Liu L, Guan H, Shao S. PRP19 upregulation inhibits cell proliferation in lung adenocarcinomas by p21-mediated induction of cell cycle arrest. Biomed Pharmacother 2014; 68:463-70. [DOI: 10.1016/j.biopha.2014.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/04/2014] [Indexed: 11/25/2022] Open
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46
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Valadkhan S. The role of snRNAs in spliceosomal catalysis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 120:195-228. [PMID: 24156945 DOI: 10.1016/b978-0-12-381286-5.00006-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The spliceosomes, large ribonucleoprotein (RNP) assemblies that remove the intervening sequences from pre-mRNAs, contain a large number of proteins and five small nuclear RNAs (snRNAs). One snRNA, U6, contains highly conserved sequences that are thought to be the functional counterparts of the RNA elements that form the active site of self-splicing group II intron ribozymes. An in vitro-assembled, protein-free complex of U6 with U2, the base-pairing partner in the spliceosomal catalytic core, can catalyze a two-step splicing reaction in the absence of all other spliceosomal factors, suggesting that the two snRNAs may form all or a large share of the spliceosomal active site. On the other hand, several spliceosomal proteins are thought to help in the formation of functionally required RNA-RNA interactions in the catalytic core. Whether they also contribute functional groups to the spliceosomal active site, and thus whether the spliceosomes are RNA or RNP enzymes remain uncertain.
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Affiliation(s)
- Saba Valadkhan
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA
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47
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Lu S, Wang R, Cai C, Liang J, Xu L, Miao S, Wang L, Song W. Small kinetochore associated protein (SKAP) promotes UV-induced cell apoptosis through negatively regulating pre-mRNA processing factor 19 (Prp19). PLoS One 2014; 9:e92712. [PMID: 24718257 PMCID: PMC3981699 DOI: 10.1371/journal.pone.0092712] [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: 11/30/2013] [Accepted: 02/25/2014] [Indexed: 01/14/2023] Open
Abstract
Apoptosis is a regulated cellular suicide program that is critical for the development and maintenance of healthy tissues. Previous studies have shown that small kinetochore associated protein (SKAP) cooperates with kinetochore and mitotic spindle proteins to regulate mitosis. However, the role of SKAP in apoptosis has not been investigated. We have identified a new interaction involving SKAP, and we propose a mechanism through which SKAP regulates cell apoptosis. Our experiments demonstrate that both overexpression and knockdown of SKAP sensitize cells to UV-induced apoptosis. Further study has revealed that SKAP interacts with Pre-mRNA processing Factor 19 (Prp19). We find that UV-induced apoptosis can be inhibited by ectopic expression of Prp19, whereas silencing Prp19 has the opposite effect. Additionally, SKAP negatively regulates the protein levels of Prp19, whereas Prp19 does not alter SKAP expression. Finally, rescue experiments demonstrate that the pro-apoptotic role of SKAP is executed through Prp19. Taken together, these findings suggest that SKAP promotes UV-induced cell apoptosis by negatively regulating the anti-apoptotic protein Prp19.
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Affiliation(s)
- Shan Lu
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Renxian Wang
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Congli Cai
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Junbo Liang
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Longchang Xu
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Shiying Miao
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Linfang Wang
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Wei Song
- State Key Laboratory of Medical Molecular Biology, Dept. of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- * E-mail:
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48
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Chen W, Shulha HP, Ashar-Patel A, Yan J, Green KM, Query CC, Rhind N, Weng Z, Moore MJ. Endogenous U2·U5·U6 snRNA complexes in S. pombe are intron lariat spliceosomes. RNA (NEW YORK, N.Y.) 2014; 20:308-20. [PMID: 24442611 PMCID: PMC3923126 DOI: 10.1261/rna.040980.113] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Excision of introns from pre-mRNAs is mediated by the spliceosome, a multi-megadalton complex consisting of U1, U2, U4/U6, and U5 snRNPs plus scores of associated proteins. Spliceosome assembly and disassembly are highly dynamic processes involving multiple stable intermediates. In this study, we utilized a split TAP-tag approach for large-scale purification of an abundant endogenous U2·U5·U6 complex from Schizosaccharomyces pombe. RNAseq revealed this complex to largely contain excised introns, indicating that it is primarily ILS (intron lariat spliceosome) complexes. These endogenous ILS complexes are remarkably resistant to both high-salt and nuclease digestion. Mass spectrometry analysis identified 68, 45, and 43 proteins in low-salt-, high-salt-, and micrococcal nuclease-treated preps, respectively. The protein content of a S. pombe ILS complex strongly resembles that previously reported for human spliced product (P) and Saccharomyces cerevisiae ILS complexes assembled on single pre-mRNAs in vitro. However, the ATP-dependent RNA helicase Brr2 was either substoichiometric in low-salt preps or completely absent from high-salt and MNase preps. Because Brr2 facilitates spliceosome disassembly, its relative absence may explain why the ILS complex accumulates logarithmically growing cultures and the inability of S. pombe extracts to support in vitro splicing.
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Affiliation(s)
- Weijun Chen
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Hennady P. Shulha
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Ami Ashar-Patel
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Jing Yan
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Karin M. Green
- UMMS Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | | | - Nick Rhind
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Zhiping Weng
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Melissa J. Moore
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
- Corresponding authorE-mail
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49
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Schmidt C, Grønborg M, Deckert J, Bessonov S, Conrad T, Lührmann R, Urlaub H. Mass spectrometry-based relative quantification of proteins in precatalytic and catalytically active spliceosomes by metabolic labeling (SILAC), chemical labeling (iTRAQ), and label-free spectral count. RNA (NEW YORK, N.Y.) 2014; 20:406-20. [PMID: 24448447 PMCID: PMC3923134 DOI: 10.1261/rna.041244.113] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The spliceosome undergoes major changes in protein and RNA composition during pre-mRNA splicing. Knowing the proteins-and their respective quantities-at each spliceosomal assembly stage is critical for understanding the molecular mechanisms and regulation of splicing. Here, we applied three independent mass spectrometry (MS)-based approaches for quantification of these proteins: (1) metabolic labeling by SILAC, (2) chemical labeling by iTRAQ, and (3) label-free spectral count for quantification of the protein composition of the human spliceosomal precatalytic B and catalytic C complexes. In total we were able to quantify 157 proteins by at least two of the three approaches. Our quantification shows that only a very small subset of spliceosomal proteins (the U5 and U2 Sm proteins, a subset of U5 snRNP-specific proteins, and the U2 snRNP-specific proteins U2A' and U2B'') remains unaltered upon transition from the B to the C complex. The MS-based quantification approaches classify the majority of proteins as dynamically associated specifically with the B or the C complex. In terms of experimental procedure and the methodical aspect of this work, we show that metabolically labeled spliceosomes are functionally active in terms of their assembly and splicing kinetics and can be utilized for quantitative studies. Moreover, we obtain consistent quantification results from all three methods, including the relatively straightforward and inexpensive label-free spectral count technique.
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Affiliation(s)
- Carla Schmidt
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Mads Grønborg
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Jochen Deckert
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Sergey Bessonov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Thomas Conrad
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Bioanalytics, Department of Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
- Corresponding authorE-mail
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50
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Ahn JW, Kim S, Kim EJ, Kim YJ, Kim KJ. Structural insights into the novel ARM-repeat protein CTNNBL1 and its association with the hPrp19-CDC5L complex. ACTA ACUST UNITED AC 2014; 70:780-8. [PMID: 24598747 DOI: 10.1107/s139900471303318x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 12/08/2013] [Indexed: 11/10/2022]
Abstract
The hPrp19-CDC5L complex plays a crucial role during human pre-mRNA splicing by catalytic activation of the spliceosome. In order to elucidate the molecular architecture of the hPrp19-CDC5L complex, the crystal structure of CTNNBL1, one of the major components of this complex, was determined. Unlike canonical ARM-repeat proteins such as β-catenin and importin-α, CTNNBL1 was found to contain a twisted and extended ARM-repeat structure at the C-terminal domain and, more importantly, the protein formed a stable dimer. A highly negatively charged patch formed in the N-terminal ARM-repeat domain of CTNNBL1 provides a binding site for CDC5L, a binding partner of the protein in the hPrp19-CDC5L complex, and these two proteins form a complex with a stoichiometry of 2:2. These findings not only present the crystal structure of a novel ARM-repeat protein, CTNNBL1, but also provide insights into the detailed molecular architecture of the hPrp19-CDC5L complex.
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Affiliation(s)
- Jae-Woo Ahn
- Structural and Molecular Biology Laboratory, School of Life Sciences and Biotechnology, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea
| | - Sangwoo Kim
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Eun-Jung Kim
- Structural and Molecular Biology Laboratory, School of Life Sciences and Biotechnology, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea
| | - Yeo-Jin Kim
- Structural and Molecular Biology Laboratory, School of Life Sciences and Biotechnology, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea
| | - Kyung-Jin Kim
- Structural and Molecular Biology Laboratory, School of Life Sciences and Biotechnology, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea
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