1
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Nugent PJ, Park H, Wladyka CL, Chen KY, Bynum C, Quarterman G, Hsieh AC, Subramaniam AR. Decoding RNA Metabolism by RNA-linked CRISPR Screening in Human Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605204. [PMID: 39091804 PMCID: PMC11291135 DOI: 10.1101/2024.07.25.605204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
RNAs undergo a complex choreography of metabolic processes in human cells that are regulated by thousands of RNA-associated proteins. While the effects of individual RNA-associated proteins on RNA metabolism have been extensively characterized, the full complement of regulators for most RNA metabolic events remain unknown. Here we present a massively parallel RNA-linked CRISPR (ReLiC) screening approach to measure the responses of diverse RNA metabolic events to knockout of 2,092 human genes encoding all known RNA-associated proteins. ReLiC screens highlight modular interactions between gene networks regulating splicing, translation, and decay of mRNAs. When combined with biochemical fractionation of polysomes, ReLiC reveals striking pathway-specific coupling between growth fitness and mRNA translation. Perturbing different components of the translation and proteostasis machineries have distinct effects on ribosome occupancy, while perturbing mRNA transcription leaves ribosome occupancy largely intact. Isoform-selective ReLiC screens capture differential regulation of intron retention and exon skipping by SF3b complex subunits. Chemogenomic screens using ReLiC decipher translational regulators upstream of mRNA decay and uncover a role for the ribosome collision sensor GCN1 during treatment with the anti-leukemic drug homoharringtonine. Our work demonstrates ReLiC as a versatile platform for discovering and dissecting regulatory principles of human RNA metabolism.
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2
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Ares M, Igel H, Katzman S, Donohue JP. Intron lariat spliceosomes convert lariats to true circles: implications for intron transposition. Genes Dev 2024; 38:322-335. [PMID: 38724209 PMCID: PMC11146597 DOI: 10.1101/gad.351764.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 04/24/2024] [Indexed: 05/21/2024]
Abstract
Rare, full-length circular intron RNAs distinct from lariats have been reported in several species, but their biogenesis is not understood. We envisioned and tested a hypothesis for their formation using Saccharomyces cerevisiae, documenting full-length and novel processed circular RNAs from multiple introns. Evidence implicates a previously undescribed catalytic activity of the intron lariat spliceosome (ILS) in which the 3'-OH of the lariat tail (with optional trimming and adenylation by the nuclear 3' processing machinery) attacks the branch, joining the intron 3' end to the 5' splice site in a 3'-5' linked circle. Human U2 and U12 spliceosomes produce analogous full-length and processed circles. Postsplicing catalytic activity of the spliceosome may promote intron transposition during eukaryotic genome evolution.
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Affiliation(s)
- Manuel Ares
- Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, California 95064, USA;
- Genomics Institute, University of California, Santa Cruz, Santa Cruz, California 95064, USA
| | - Haller Igel
- Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, California 95064, USA
| | - Sol Katzman
- Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, California 95064, USA
- Genomics Institute, University of California, Santa Cruz, Santa Cruz, California 95064, USA
| | - John P Donohue
- Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, California 95064, USA
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3
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Ares M, Igel H, Katzman S, Donohue JP. Intron-lariat spliceosomes convert lariats to true circles: implications for intron transposition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586863. [PMID: 38585890 PMCID: PMC10996645 DOI: 10.1101/2024.03.26.586863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Rare, full length circular intron RNAs distinct from lariats have been reported in several species, but their biogenesis is not understood. We envision and test a hypothesis for their formation using Saccharomyces cerevisiae, documenting full length and novel processed circular RNAs from multiple introns. Evidence implicates a previously undescribed catalytic activity of the intron-lariat spliceosome (ILS) in which the 3'-OH of the lariat tail (with optional trimming and adenylation by the nuclear 3' processing machinery) attacks the branch, joining the intron 3' end to the 5' splice site in a 3'-5' linked circle. Human U2 and U12 spliceosomes produce analogous full length and processed circles. Post-splicing catalytic activity of the spliceosome may promote intron transposition during eukaryotic genome evolution.
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Affiliation(s)
- Manuel Ares
- Center for Molecular Biology of RNA, University of California, Santa Cruz
- Genomics Institute, Santa Cruz, CA 95064 USA
| | - Haller Igel
- Center for Molecular Biology of RNA, University of California, Santa Cruz
| | - Sol Katzman
- Center for Molecular Biology of RNA, University of California, Santa Cruz
- Genomics Institute, Santa Cruz, CA 95064 USA
| | - John P. Donohue
- Center for Molecular Biology of RNA, University of California, Santa Cruz
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4
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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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5
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Beusch I, Rao B, Studer MK, Luhovska T, Šukytė V, Lei S, Oses-Prieto J, SeGraves E, Burlingame A, Jonas S, Madhani HD. Targeted high-throughput mutagenesis of the human spliceosome reveals its in vivo operating principles. Mol Cell 2023; 83:2578-2594.e9. [PMID: 37402368 PMCID: PMC10484158 DOI: 10.1016/j.molcel.2023.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 03/15/2023] [Accepted: 06/02/2023] [Indexed: 07/06/2023]
Abstract
The spliceosome is a staggeringly complex machine, comprising, in humans, 5 snRNAs and >150 proteins. We scaled haploid CRISPR-Cas9 base editing to target the entire human spliceosome and investigated the mutants using the U2 snRNP/SF3b inhibitor, pladienolide B. Hypersensitive substitutions define functional sites in the U1/U2-containing A complex but also in components that act as late as the second chemical step after SF3b is dissociated. Viable resistance substitutions map not only to the pladienolide B-binding site but also to the G-patch domain of SUGP1, which lacks orthologs in yeast. We used these mutants and biochemical approaches to identify the spliceosomal disassemblase DHX15/hPrp43 as the ATPase ligand for SUGP1. These and other data support a model in which SUGP1 promotes splicing fidelity by triggering early spliceosome disassembly in response to kinetic blocks. Our approach provides a template for the analysis of essential cellular machines in humans.
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Affiliation(s)
- Irene Beusch
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, USA
| | - Beiduo Rao
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, USA
| | - Michael K Studer
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Tetiana Luhovska
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Viktorija Šukytė
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Susan Lei
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, USA
| | - Juan Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, USA
| | - Em SeGraves
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, USA
| | - Alma Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, USA
| | - Stefanie Jonas
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, USA.
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6
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The Terminal Extensions of Dbp7 Influence Growth and 60S Ribosomal Subunit Biogenesis in Saccharomyces cerevisiae. Int J Mol Sci 2023; 24:ijms24043460. [PMID: 36834876 PMCID: PMC9960301 DOI: 10.3390/ijms24043460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 01/30/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Ribosome synthesis is a complex process that involves a large set of protein trans-acting factors, among them DEx(D/H)-box helicases. These are enzymes that carry out remodelling activities onto RNAs by hydrolysing ATP. The nucleolar DEGD-box protein Dbp7 is required for the biogenesis of large 60S ribosomal subunits. Recently, we have shown that Dbp7 is an RNA helicase that regulates the dynamic base-pairing between the snR190 small nucleolar RNA and the precursors of the ribosomal RNA within early pre-60S ribosomal particles. As the rest of DEx(D/H)-box proteins, Dbp7 has a modular organization formed by a helicase core region, which contains conserved motifs, and variable, non-conserved N- and C-terminal extensions. The role of these extensions remains unknown. Herein, we show that the N-terminal domain of Dbp7 is necessary for efficient nuclear import of the protein. Indeed, a basic bipartite nuclear localization signal (NLS) could be identified in its N-terminal domain. Removal of this putative NLS impairs, but does not abolish, Dbp7 nuclear import. Both N- and C-terminal domains are required for normal growth and 60S ribosomal subunit synthesis. Furthermore, we have studied the role of these domains in the association of Dbp7 with pre-ribosomal particles. Altogether, our results show that the N- and C-terminal domains of Dbp7 are important for the optimal function of this protein during ribosome biogenesis.
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7
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Klimešová K, Petržílková H, Bařinka C, Staněk D. SART3 associates with a post-splicing complex. J Cell Sci 2023; 136:jcs260380. [PMID: 36620952 DOI: 10.1242/jcs.260380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 12/10/2022] [Indexed: 01/10/2023] Open
Abstract
SART3 is a multifunctional protein that acts in several steps of gene expression, including assembly and recycling of the spliceosomal U4/U6 small nuclear ribonucleoprotein particle (snRNP). In this work, we provide evidence that SART3 associates via its N-terminal HAT domain with the 12S U2 snRNP. Further analysis showed that SART3 associates with the post-splicing complex containing U2 and U5 snRNP components. In addition, we observed an interaction between SART3 and the RNA helicase DHX15, which disassembles post-splicing complexes. Based on our data, we propose a model that SART3 associates via its N-terminal HAT domain with the post-splicing complex, where it interacts with U6 snRNA to protect it and to initiate U6 snRNA recycling before a next round of splicing.
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MESH Headings
- RNA Splicing/genetics
- Spliceosomes/genetics
- Spliceosomes/metabolism
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Ribonucleoprotein, U4-U6 Small Nuclear/genetics
- Ribonucleoprotein, U4-U6 Small Nuclear/metabolism
- Ribonucleoprotein, U5 Small Nuclear/genetics
- Ribonucleoprotein, U5 Small Nuclear/metabolism
- Ribonucleoprotein, U2 Small Nuclear/genetics
- Ribonucleoprotein, U2 Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
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Affiliation(s)
- Klára Klimešová
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Hana Petržílková
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Cyril Bařinka
- Laboratory of Structural Biology, Institute of Biotechnology, Czech Academy of Sciences, 252 50 Prague, Czech Republic
| | - David Staněk
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
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8
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Bohnsack KE, Kanwal N, Bohnsack MT. Prp43/DHX15 exemplify RNA helicase multifunctionality in the gene expression network. Nucleic Acids Res 2022; 50:9012-9022. [PMID: 35993807 PMCID: PMC9458436 DOI: 10.1093/nar/gkac687] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/10/2022] [Accepted: 08/01/2022] [Indexed: 12/24/2022] Open
Abstract
Dynamic regulation of RNA folding and structure is critical for the biogenesis and function of RNAs and ribonucleoprotein (RNP) complexes. Through their nucleotide triphosphate-dependent remodelling functions, RNA helicases are key modulators of RNA/RNP structure. While some RNA helicases are dedicated to a specific target RNA, others are multifunctional and engage numerous substrate RNAs in different aspects of RNA metabolism. The discovery of such multitasking RNA helicases raises the intriguing question of how these enzymes can act on diverse RNAs but also maintain specificity for their particular targets within the RNA-dense cellular environment. Furthermore, the identification of RNA helicases that sit at the nexus between different aspects of RNA metabolism raises the possibility that they mediate cross-regulation of different cellular processes. Prominent and extensively characterized multifunctional DEAH/RHA-box RNA helicases are DHX15 and its Saccharomyces cerevisiae (yeast) homologue Prp43. Due to their central roles in key cellular processes, these enzymes have also served as prototypes for mechanistic studies elucidating the mode of action of this type of enzyme. Here, we summarize the current knowledge on the structure, regulation and cellular functions of Prp43/DHX15, and discuss the general concept and implications of RNA helicase multifunctionality.
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Affiliation(s)
- Katherine E Bohnsack
- Correspondence may also be addressed to Katherine E. Bohnsack. Tel: +49 551 3969305; Fax: +49 551 395960;
| | - Nidhi Kanwal
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- To whom correspondence should be addressed. Tel: +49 551 395968; Fax: +49 551 395960;
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9
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Huang TC, Chen YJ. Do Personality Traits Matter? Exploring Anti-drug Behavioral Patterns in a Computer-Assisted Situated Learning Environment. Front Psychol 2022; 13:812793. [PMID: 35668971 PMCID: PMC9163499 DOI: 10.3389/fpsyg.2022.812793] [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: 11/10/2021] [Accepted: 04/28/2022] [Indexed: 11/17/2022] Open
Abstract
Drug abuse has been and continues to be, a common social issue worldwide, yet the efficiency of widely adopted sweeping speech for anti-drug campaigns has proven inefficient. To provide students with a safe and efficient learning situation related to drug refusal skills, we used a novel approach rooted in a serious learning game and concept map during a brief extracurricular period to help students understand drugs and their negative effects. The proposed game-based situational learning system allowed all students to participate simultaneously and individually in multiple scenarios of drug temptation posed by peers and classmates to practice responding and refusing drugs in school and community settings. Moreover, to explore whether different personality traits (such as the Big Five personality traits) result in different anti-drug responses, we used a serious game to conduct an anti-drug experiment on 53 junior middle school students aged 13–15. Each participant’s decision-making process was recorded in the serious game as behavioral patterns for lag sequential analysis (LSA). The outcomes revealed seven behavioral patterns including differentiation (D), acceptance (A), effective (ER) and ineffective responses (IR), effective (ES) and ineffective solution-seeking (IS), and failure to refuse (F). The GSEQ (Generalized Sequential Querier) which is a computer program for analyzing sequential observational data was used. The results indicated the following: (1) Neuroticism was performed at a relatively low level under the guidance of a concept map. (2) “Neuroticism” was associated with the lowest risk of accepting drugs. (3) Students with “openness to experiences” were at high risk of accepting drugs. (4) Almost all personality behavioral transition diagrams showed that failure to refuse (F) drugs was followed by inefficient seeking of help (SI) and inefficient refusal (RI). These findings provide reference points for designing adaptive anti-drug education programs.
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Affiliation(s)
- Tien-Chi Huang
- Department of Information Management, National Taichung University of Science and Technology, Taichung, Taiwan
| | - Yu-Jie Chen
- Department of Information Management, National Taichung University of Science and Technology, Taichung, Taiwan
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10
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Bailey AD, Talkish J, Ding H, Igel H, Duran A, Mantripragada S, Paten B, Ares M. Concerted modification of nucleotides at functional centers of the ribosome revealed by single-molecule RNA modification profiling. eLife 2022; 11:e76562. [PMID: 35384842 PMCID: PMC9045821 DOI: 10.7554/elife.76562] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 04/05/2022] [Indexed: 12/02/2022] Open
Abstract
Nucleotides in RNA and DNA are chemically modified by numerous enzymes that alter their function. Eukaryotic ribosomal RNA (rRNA) is modified at more than 100 locations, particularly at highly conserved and functionally important nucleotides. During ribosome biogenesis, modifications are added at various stages of assembly. The existence of differently modified classes of ribosomes in normal cells is unknown because no method exists to simultaneously evaluate the modification status at all sites within a single rRNA molecule. Using a combination of yeast genetics and nanopore direct RNA sequencing, we developed a reliable method to track the modification status of single rRNA molecules at 37 sites in 18 S rRNA and 73 sites in 25 S rRNA. We use our method to characterize patterns of modification heterogeneity and identify concerted modification of nucleotides found near functional centers of the ribosome. Distinct, undermodified subpopulations of rRNAs accumulate upon loss of Dbp3 or Prp43 RNA helicases, suggesting overlapping roles in ribosome biogenesis. Modification profiles are surprisingly resistant to change in response to many genetic and acute environmental conditions that affect translation, ribosome biogenesis, and pre-mRNA splicing. The ability to capture single-molecule RNA modification profiles provides new insights into the roles of nucleotide modifications in RNA function.
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Affiliation(s)
- Andrew D Bailey
- Department of Biomolecular Engineering and Santa Cruz Genomics Institute, University of California, Santa CruzSanta CruzUnited States
| | - Jason Talkish
- RNA Center and Department of Molecular, Cell & Developmental Biology, University of California, Santa CruzSanta CruzUnited States
| | - Hongxu Ding
- Department of Biomolecular Engineering and Santa Cruz Genomics Institute, University of California, Santa CruzSanta CruzUnited States
- Department of Pharmacy Practice & Science, College of Pharmacy, University of ArizonaTucsonUnited States
| | - Haller Igel
- RNA Center and Department of Molecular, Cell & Developmental Biology, University of California, Santa CruzSanta CruzUnited States
| | | | | | - Benedict Paten
- Department of Biomolecular Engineering and Santa Cruz Genomics Institute, University of California, Santa CruzSanta CruzUnited States
| | - Manuel Ares
- RNA Center and Department of Molecular, Cell & Developmental Biology, University of California, Santa CruzSanta CruzUnited States
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11
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Du Pont KE, McCullagh M, Geiss BJ. Conserved motifs in the flavivirus NS3 RNA helicase enzyme. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1688. [PMID: 34472205 PMCID: PMC8888775 DOI: 10.1002/wrna.1688] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
Flaviviruses are a major health concern because over half of the world population is at risk of infection and there are very few antiviral therapeutics to treat diseases resulting from infection. Replication is an essential part of the flavivirus survival. One of the viral proteins, NS3 helicase, is critical for unwinding the double stranded RNA intermediate during flaviviral replication. The helicase performs the unwinding of the viral RNA intermediate structure in an ATP-dependent manner. NS3 helicase is a member of the Viral/DEAH-like subfamily of the superfamily 2 helicase containing eight highly conserved structural motifs (I, Ia, II, III, IV, IVa, V, and VI) localized between the ATP-binding and RNA-binding pockets. Of these structural motifs only three are well characterized for function in flaviviruses (I, II, and VI). The roles of the other structural motifs are not well understood for NS3 helicase function, but comparison of NS3 with other superfamily 2 helicases within the viral/DEAH-like, DEAH/RHA, and DEAD-box subfamilies can be used to elucidate the roles of these structural motifs in the flavivirus NS3 helicase. This review aims to summarize the role of each conserved structural motif within flavivirus NS3 in RNA helicase function. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Kelly E. Du Pont
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
| | - Martin McCullagh
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Brian J. Geiss
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA
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12
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Karbstein K. Attacking a DEAD problem: The role of DEAD-box ATPases in ribosome assembly and beyond. Methods Enzymol 2022; 673:19-38. [PMID: 35965007 PMCID: PMC10154911 DOI: 10.1016/bs.mie.2022.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
DEAD-box proteins are a subfamily of ATPases with similarity to RecA-type helicases that are involved in all aspects of RNA Biology. Despite their potential to regulate these processes via their RNA-dependent ATPase activity, their roles remain poorly characterized. Here I describe a roadmap to study these proteins in the context of ribosome assembly, the process that utilizes more than half of all DEAD-box proteins encoded in the yeast genome.
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Affiliation(s)
- Katrin Karbstein
- Department of Integrative Structural and Computational Biology, Scripps Florida, Jupiter, FL, United States; HHMI Faculty Scholar, Chevy Chase, MD, United States; The Skaggs Graduate School of Chemical and Biological Sciences, Scripps Florida, Jupiter, FL, United States.
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13
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Mitterer V, Pertschy B. RNA folding and functions of RNA helicases in ribosome biogenesis. RNA Biol 2022; 19:781-810. [PMID: 35678541 PMCID: PMC9196750 DOI: 10.1080/15476286.2022.2079890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic ribosome biogenesis involves the synthesis of ribosomal RNA (rRNA) and its stepwise folding into the unique structure present in mature ribosomes. rRNA folding starts already co-transcriptionally in the nucleolus and continues when pre-ribosomal particles further maturate in the nucleolus and upon their transit to the nucleoplasm and cytoplasm. While the approximate order of folding of rRNA subdomains is known, especially from cryo-EM structures of pre-ribosomal particles, the actual mechanisms of rRNA folding are less well understood. Both small nucleolar RNAs (snoRNAs) and proteins have been implicated in rRNA folding. snoRNAs hybridize to precursor rRNAs (pre-rRNAs) and thereby prevent premature folding of the respective rRNA elements. Ribosomal proteins (r-proteins) and ribosome assembly factors might have a similar function by binding to rRNA elements and preventing their premature folding. Besides that, a small group of ribosome assembly factors are thought to play a more active role in rRNA folding. In particular, multiple RNA helicases participate in individual ribosome assembly steps, where they are believed to coordinate RNA folding/unfolding events or the release of proteins from the rRNA. In this review, we summarize the current knowledge on mechanisms of RNA folding and on the specific function of the individual RNA helicases involved. As the yeast Saccharomyces cerevisiae is the organism in which ribosome biogenesis and the role of RNA helicases in this process is best studied, we focused our review on insights from this model organism, but also make comparisons to other organisms where applicable.
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Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, Heidelberg, Germany
- BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, Graz, Austria
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14
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Martín E, Vivori C, Rogalska M, Herrero-Vicente J, Valcárcel J. Alternative splicing regulation of cell-cycle genes by SPF45/SR140/CHERP complex controls cell proliferation. RNA (NEW YORK, N.Y.) 2021; 27:1557-1576. [PMID: 34544891 PMCID: PMC8594467 DOI: 10.1261/rna.078935.121] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/11/2021] [Indexed: 06/10/2023]
Abstract
The regulation of pre-mRNA processing has important consequences for cell division and the control of cancer cell proliferation, but the underlying molecular mechanisms remain poorly understood. We report that three splicing factors, SPF45, SR140, and CHERP, form a tight physical and functionally coherent complex that regulates a variety of alternative splicing events, frequently by repressing short exons flanked by suboptimal 3' splice sites. These comprise alternative exons embedded in genes with important functions in cell-cycle progression, including the G2/M key regulator FOXM1 and the spindle regulator SPDL1. Knockdown of either of the three factors leads to G2/M arrest and to enhanced apoptosis in HeLa cells. Promoting the changes in FOXM1 or SPDL1 splicing induced by SPF45/SR140/CHERP knockdown partially recapitulates the effects on cell growth, arguing that the complex orchestrates a program of alternative splicing necessary for efficient cell proliferation.
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Affiliation(s)
- Elena Martín
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
| | - Claudia Vivori
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
| | - Malgorzata Rogalska
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - Jorge Herrero-Vicente
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08003, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
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15
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Ribera J, Portolés I, Córdoba-Jover B, Rodríguez-Vita J, Casals G, González-de la Presa B, Graupera M, Solsona-Vilarrasa E, Garcia-Ruiz C, Fernández-Checa JC, Soria G, Tudela R, Esteve-Codina A, Espadas G, Sabidó E, Jiménez W, Sessa WC, Morales-Ruiz M. The loss of DHX15 impairs endothelial energy metabolism, lymphatic drainage and tumor metastasis in mice. Commun Biol 2021; 4:1192. [PMID: 34654883 PMCID: PMC8519955 DOI: 10.1038/s42003-021-02722-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 09/24/2021] [Indexed: 01/29/2023] Open
Abstract
DHX15 is a downstream substrate for Akt1, which is involved in key cellular processes affecting vascular biology. Here, we explored the vascular regulatory function of DHX15. Homozygous DHX15 gene deficiency was lethal in mouse and zebrafish embryos. DHX15-/- zebrafish also showed downregulation of VEGF-C and reduced formation of lymphatic structures during development. DHX15+/- mice depicted lower vascular density and impaired lymphatic function postnatally. RNAseq and proteome analysis of DHX15 silenced endothelial cells revealed differential expression of genes involved in the metabolism of ATP biosynthesis. The validation of these results demonstrated a lower activity of the Complex I in the mitochondrial membrane of endothelial cells, resulting in lower intracellular ATP production and lower oxygen consumption. After injection of syngeneic LLC1 tumor cells, DHX15+/- mice showed partially inhibited primary tumor growth and reduced lung metastasis. Our results revealed an important role of DHX15 in vascular physiology and pave a new way to explore its potential use as a therapeutical target for metastasis treatment.
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Affiliation(s)
- Jordi Ribera
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Irene Portolés
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Bernat Córdoba-Jover
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Juan Rodríguez-Vita
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- German Cancer Research Center, Heidelberg, Germany
| | - Gregori Casals
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Bernardino González-de la Presa
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
| | - Mariona Graupera
- Vascular Signalling Laboratory, Program Against Cancer Therapeutic Resistance (ProCURE), Institut d'Investigació Biomèdica de Bellvitge (IDIBELL). CIBERonc, Barcelona, Spain
| | - Estel Solsona-Vilarrasa
- Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Científicas (CSIC), Liver Unit, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, 08036, Spain
- CIBERehd, Instituto de Salud Carlos III, Madrid, 28029, Spain
| | - Carmen Garcia-Ruiz
- Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Científicas (CSIC), Liver Unit, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, 08036, Spain
- CIBERehd, Instituto de Salud Carlos III, Madrid, 28029, Spain
- USC Research Center for ALPD, Keck School of Medicine, Los Angeles, CA, 90033, USA
| | - José C Fernández-Checa
- Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), Consejo Superior Investigaciones Científicas (CSIC), Liver Unit, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, 08036, Spain
- CIBERehd, Instituto de Salud Carlos III, Madrid, 28029, Spain
- USC Research Center for ALPD, Keck School of Medicine, Los Angeles, CA, 90033, USA
| | - Guadalupe Soria
- Experimental 7T-MRI Unit, IDIBAPS, Barcelona, Spain
- CIBERbbn, University of Barcelona, Barcelona, Spain
| | - Raúl Tudela
- Experimental 7T-MRI Unit, IDIBAPS, Barcelona, Spain
- CIBERbbn, University of Barcelona, Barcelona, Spain
| | - Anna Esteve-Codina
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Guadalupe Espadas
- Proteomics Unit, Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Universitat Pompeu Fabra, Barcelona, Spain
| | - Eduard Sabidó
- Proteomics Unit, Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Universitat Pompeu Fabra, Barcelona, Spain
| | - Wladimiro Jiménez
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
- Department of Biomedicine-Biochemistry Unit, School of Medicine University of Barcelona, Barcelona, Spain
| | - William C Sessa
- Department of Pharmacology, Department of Cardiology, Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT, USA
| | - Manuel Morales-Ruiz
- Biochemistry and Molecular Genetics Department, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain.
- Department of Biomedicine-Biochemistry Unit, School of Medicine University of Barcelona, Barcelona, Spain.
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16
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Cai Y, Wang J, Jin D, Liu Q, Chen X, Pan L, Li Y, Wang X, Qian F, Wang J, Zhong TP, Wang S. Dhx15 regulates zebrafish definitive hematopoiesis through the unfolded protein response pathway. Cancer Sci 2021; 112:3884-3894. [PMID: 34077586 PMCID: PMC8409414 DOI: 10.1111/cas.15002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/27/2022] Open
Abstract
Gene alterations are recognized as important events in acute myeloid leukemia (AML) progression. Studies on hematopoiesis of altered genes contribute to a better understanding on their roles in AML progression. Our previous work reported a DEAH box helicase 15 (DHX15) R222G mutation in AML patients, and we showed DHX15 overexpression is associated with poor prognosis in AML patients. In this work, we further study the role of dhx15 in zebrafish developmental hematopoiesis by generating dhx15−/− zebrafish using transcription activator‐like effector nuclease technology. Whole‐mount in situ hybridization (WISH) analysis showed hematopoietic stem/progenitor cells were dramatically perturbed when dhx15 was deleted. Immunofluorescence staining indicated inhibited hematopoietic stem/progenitor cell (HSPC) proliferation instead of accelerated apoptosis were detected in dhx15−/− zebrafish. Furthermore, our data showed that HSPC defect is mediated through the unfolded protein response (UPR) pathway. DHX15 R222G mutation, a recurrent mutation identified in AML patients, displayed a compromised function in restoring HSPC failure in dhx15−/−; Tg (hsp: DHX15 R222G) zebrafish. Collectively, this work revealed a vital role of dhx15 in the maintenance of definitive hematopoiesis in zebrafish through the unfolded protein respone pathway. The study of DHX15 and DHX15 R222G mutation could hold clinical significance for evaluating prognosis of AML patients with aberrant DHX15 expression.
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Affiliation(s)
- Yuanhua Cai
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Jing Wang
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Daqing Jin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai, China
| | - Qiao Liu
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Xianglei Chen
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Lili Pan
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China.,Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Yang Li
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China.,Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xuechun Wang
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Feng Qian
- School of Life Sciences and Institutes of Biomedical Sciences, Ministry of Education Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China
| | - Jiucun Wang
- School of Life Sciences and Institutes of Biomedical Sciences, Ministry of Education Key Laboratory of Contemporary Anthropology and State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China
| | - Tao Peter Zhong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Molecular Medicine, East China Normal University School of Life Sciences, Shanghai, China.,Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Shaoyuan Wang
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China.,Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
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17
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Menees TM. Saccharomyces cerevisiae RNA lariat debranching enzyme, Dbr1p, is required for completion of reverse transcription by the retrovirus-like element Ty1 and cleaves branched Ty1 RNAs. Mol Genet Genomics 2021; 296:409-422. [PMID: 33464395 DOI: 10.1007/s00438-020-01753-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/14/2020] [Indexed: 11/25/2022]
Abstract
RNA debranching enzymes are 2'-5' phosphodiesterases found in all eukaryotes. Their main role is cleavage of intron RNA lariat branch points, promoting RNA turnover via exonucleases. Consistent with this role, cells with reduced RNA debranching enzyme activity accumulate intron RNA lariats. The Saccharomyces cerevisiae RNA debranching enzyme Dbr1p is also a host factor for the yeast long terminal repeat (LTR) retrotransposon Ty1, a model for many aspects of retroviral replication. Fittingly, the human RNA debranching enzyme Dbr1 is a host factor for the human immunodeficiency virus, HIV-1. The yeast and human RNA debranching enzymes act at the reverse transcription stages for Ty1 and HIV-1, respectively. Although efficient production of full-length Ty1 cDNA requires Dbr1p, the findings reported here indicate that production of the earliest distinct cDNA product, minus strand strong stop DNA (-sssDNA), is equivalent in wild type and dbr1∆ mutant cells. Several branched Ty1 RNAs are shown to accumulate in dbr1∆ cells during retrotransposition. These data are consistent with creation of Ty1 RNA branches prior to Ty1 reverse transcription and their removal by Dbr1p to allow efficient extension of early cDNA products. The data support the possibility that RNA branch formation and cleavage play broadly shared, but unknown roles in retroviral and LTR retrotransposon reverse transcription.
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Affiliation(s)
- Thomas M Menees
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA.
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18
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Mouffok S, Capeyrou R, Belhabich-Baumas K, Joret C, Henras AK, Humbert O, Henry Y. The G-patch activators Pfa1 and PINX1 exhibit different modes of interaction with the Prp43 RNA helicase. RNA Biol 2020; 18:510-522. [PMID: 32882145 DOI: 10.1080/15476286.2020.1818458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prp43 is a DEAH-box RNA helicase involved in both splicing and ribosome biogenesis. Its activities are directly stimulated by several co-activators that share a G-patch domain. The substrates of Prp43, its mechanism of action and the modes of interaction with and activation by G-patch proteins have been only partially characterized. We investigated how Pfa1 and PINX1, two G-patch proteins involved in ribosome biogenesis, interact with Prp43. We demonstrate that a protruding loop connecting the β4 and β5 strands of Prp43 OB fold is crucial for the binding of the G-patch domain of Pfa1. However, neither this loop nor the entire OB fold of Prp43 is essential for PINX1 binding. We conclude that the binding modes of Pfa1 and PINX1 G-patches to Prp43 are different. Nevertheless, stimulation of the ATPase and helicase activities of Prp43 by both full-length Pfa1 and PINX1 requires the β4-β5 loop. Moreover, we show that disruption of this loop completely abrogates Prp43 activity during yeast ribosome biogenesis but does not prevent its integration within pre-ribosomal particles. We propose that the β4-β5 loop plays a crucial role in the transmission of conformational changes induced by binding of the G-patch to Prp43 active site and substrate RNA.
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Affiliation(s)
- Saïda Mouffok
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Régine Capeyrou
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Kamila Belhabich-Baumas
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Clément Joret
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Odile Humbert
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
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19
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McElderry J, Carrington B, Bishop K, Kim E, Pei W, Chen Z, Ramanagoudr-Bhojappa R, Prakash A, Burgess SM, Liu PP, Sood R. Splicing factor DHX15 affects tp53 and mdm2 expression via alternate splicing and promoter usage. Hum Mol Genet 2020; 28:4173-4185. [PMID: 31691804 DOI: 10.1093/hmg/ddz261] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/18/2019] [Accepted: 10/24/2019] [Indexed: 12/21/2022] Open
Abstract
DHX15, a DEAH box containing RNA helicase, is a splicing factor required for the last step of splicing. Recent studies identified a recurrent mutational hotspot, R222G, in DHX15 in ∼ 6% of acute myeloid leukemia (AML) patients that carry the fusion protein RUNX1-RUNX1T1 produced by t (8;21) (q22;q22). Studies using yeast mutants showed that substitution of G for the residue equivalent to R222 leads to loss of its helicase function, suggesting that it is a loss-of-function mutation. To elucidate the role of DHX15 during development, we established the first vertebrate knockout model with CRISPR/Cas9 in zebrafish. Our data showed that dhx15 expression is enriched in the brain, eyes, pectoral fin primordia, liver and intestinal bulb during embryonic development. Dhx15 deficiency leads to pleiotropic morphological phenotypes in homozygous mutant embryos starting at 3 days post fertilization (dpf) that result in lethality by 7 dpf, revealing an essential role during embryonic development. RNA-seq analysis suggested important roles of Dhx15 in chromatin and nucleosome assembly and regulation of the Mdm2-p53 pathway. Interestingly, exons corresponding to the alternate transcriptional start sites for tp53 and mdm2 were preferentially expressed in the mutant embryos, leading to significant upregulation of their alternate isoforms, Δ113p53 (orthologous to Δ133p53 isoform in human) and mdm2-P2 (isoform using distal promoter P2), respectively. We speculate that these alterations in the Mdm2-p53 pathway contribute to the development of AML in patients with t(8;21) and somatically mutated DHX15.
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Affiliation(s)
- John McElderry
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Blake Carrington
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin Bishop
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Erika Kim
- Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wuhong Pei
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zelin Chen
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ramanagouda Ramanagoudr-Bhojappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anupam Prakash
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shawn M Burgess
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - P Paul Liu
- Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Raman Sood
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Abstract
Splicing of the precursor messenger RNA, involving intron removal and exon ligation, is mediated by the spliceosome. Together with biochemical and genetic investigations of the past four decades, structural studies of the intact spliceosome at atomic resolution since 2015 have led to mechanistic delineation of RNA splicing with remarkable insights. The spliceosome is proven to be a protein-orchestrated metalloribozyme. Conserved elements of small nuclear RNA (snRNA) constitute the splicing active site with two catalytic metal ions and recognize three conserved intron elements through duplex formation, which are delivered into the splicing active site for branching and exon ligation. The protein components of the spliceosome stabilize the conformation of the snRNA, drive spliceosome remodeling, orchestrate the movement of the RNA elements, and facilitate the splicing reaction. The overall organization of the spliceosome and the configuration of the splicing active site are strictly conserved between human and yeast.
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Affiliation(s)
- Ruixue Wan
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
| | - Rui Bai
- Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Hangzhou 310024, China
| | - Xiechao Zhan
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China;,
- Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Hangzhou 310024, China
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21
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Abstract
RNA helicases exert mechanical force that changes RNA configurations in many essential cellular pathways, e.g., during mRNA maturation or assembly of ribosomes. DEAH helicases work by translocating along RNA and thereby unwind RNA duplexes or dissociate bound proteins. Because DEAH proteins are poor enzymes without intrinsic selectivity for target RNAs, they require adapter proteins that recruit them to functional sites and enhance their catalytic activity. One essential class of DEAH activators is formed by G-patch proteins, which bind helicases via their eponymous glycine-rich motif. We solved the structure of a G-patch bound to helicase DHX15. Our analysis suggests that G-patches tether mobile sections of DEAH helicases together and activate them by stabilizing a functional conformation with high RNA affinity. RNA helicases of the DEAH/RHA family are involved in many essential cellular processes, such as splicing or ribosome biogenesis, where they remodel large RNA–protein complexes to facilitate transitions to the next intermediate. DEAH helicases couple adenosine triphosphate (ATP) hydrolysis to conformational changes of their catalytic core. This movement results in translocation along RNA, which is held in place by auxiliary C-terminal domains. The activity of DEAH proteins is strongly enhanced by the large and diverse class of G-patch activators. Despite their central roles in RNA metabolism, insight into the molecular basis of G-patch–mediated helicase activation is missing. Here, we have solved the structure of human helicase DHX15/Prp43, which has a dual role in splicing and ribosome assembly, in complex with the G-patch motif of the ribosome biogenesis factor NKRF. The G-patch motif binds in an extended conformation across the helicase surface. It tethers the catalytic core to the flexibly attached C-terminal domains, thereby fixing a conformation that is compatible with RNA binding. Structures in the presence or absence of adenosine diphosphate (ADP) suggest that motions of the catalytic core, which are required for ATP binding, are still permitted. Concomitantly, RNA affinity, helicase, and ATPase activity of DHX15 are increased when G-patch is bound. Mutations that detach one end of the tether but maintain overall binding severely impair this enhancement. Collectively, our data suggest that the G-patch motif acts like a flexible brace between dynamic portions of DHX15 that restricts excessive domain motions but maintains sufficient flexibility for catalysis.
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22
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Wang J, Chen S, Jiang N, Li N, Wang X, Li Z, Li X, Liu H, Li L, Yang Y, Ni T, Yu C, Ma J, Zheng B, Ren G. Spliceosome disassembly factors ILP1 and NTR1 promote miRNA biogenesis in Arabidopsis thaliana. Nucleic Acids Res 2019; 47:7886-7900. [PMID: 31216029 PMCID: PMC6736097 DOI: 10.1093/nar/gkz526] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 05/13/2019] [Accepted: 06/03/2019] [Indexed: 12/23/2022] Open
Abstract
The intron-lariat spliceosome (ILS) complex is highly conserved among eukaryotes, and its disassembly marks the end of a canonical splicing cycle. In this study, we show that two conserved disassembly factors of the ILS complex, Increased Level of Polyploidy1-1D (ILP1) and NTC-Related protein 1 (NTR1), positively regulate microRNA (miRNA) biogenesis by facilitating transcriptional elongation of MIRNA (MIR) genes in Arabidopsis thaliana. ILP1 and NTR1 formed a stable complex and co-regulated alternative splicing of more than a hundred genes across the Arabidopsis genome, including some primary transcripts of miRNAs (pri-miRNAs). Intriguingly, pri-miRNAs, regardless of having introns or not, were globally down-regulated when the ILP1 or NTR1 function was compromised. ILP1 and NTR1 interacted with core miRNA processing proteins Dicer-like 1 and Serrate, and were required for proper RNA polymerase II occupancy at elongated regions of MIR chromatin, without affecting either MIR promoter activity or pri-miRNA decay. Our results provide further insights into the regulatory role of spliceosomal machineries in the biogenesis of miRNAs.
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Affiliation(s)
- Junli Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Susu Chen
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Ning Jiang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Ning Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Xiaoyan Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Zhongpeng Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Xu Li
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences, Shanghai 200032, P.R. China
| | - Hongtao Liu
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences, Shanghai 200032, P.R. China
| | - Lin Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Yu Yang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Ting Ni
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Chaoyi Yu
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Binglian Zheng
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
| | - Guodong Ren
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Huashan Hospital and School of Life Sciences, Fudan University, Shanghai 200438, P.R. China
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23
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Toroney R, Nielsen KH, Staley JP. Termination of pre-mRNA splicing requires that the ATPase and RNA unwindase Prp43p acts on the catalytic snRNA U6. Genes Dev 2019; 33:1555-1574. [PMID: 31558568 PMCID: PMC6824469 DOI: 10.1101/gad.328294.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 09/03/2019] [Indexed: 11/25/2022]
Abstract
In this study, Toroney et al. set out to identify the mechanism of Prp43p action in splicing. The authors use biochemical approaches to demonstrate that the 3' end of U6 acts as the key substrate by which Prp43p promotes disassembly and intron release, thereby terminating splicing. The termination of pre-mRNA splicing functions to discard suboptimal substrates, thereby enhancing fidelity, and to release excised introns in a manner coupled to spliceosome disassembly, thereby allowing recycling. The mechanism of termination, including the RNA target of the DEAH-box ATPase Prp43p, remains ambiguous. We discovered a critical role for nucleotides at the 3′ end of the catalytic U6 small nuclear RNA in splicing termination. Although conserved sequence at the 3′ end is not required, 2′ hydroxyls are, paralleling requirements for Prp43p biochemical activities. Although the 3′ end of U6 is not required for recruiting Prp43p to the spliceosome, the 3′ end cross-links directly to Prp43p in an RNA-dependent manner. Our data indicate a mechanism of splicing termination in which Prp43p translocates along U6 from the 3′ end to disassemble the spliceosome and thereby release suboptimal substrates or excised introns. This mechanism reveals that the spliceosome becomes primed for termination at the same stage it becomes activated for catalysis, implying a requirement for stringent control of spliceosome activity within the cell.
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Affiliation(s)
- Rebecca Toroney
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
| | - Klaus H Nielsen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
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24
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Felisberto-Rodrigues C, Thomas JC, McAndrew C, Le Bihan YV, Burke R, Workman P, van Montfort RLM. Structural and functional characterisation of human RNA helicase DHX8 provides insights into the mechanism of RNA-stimulated ADP release. Biochem J 2019; 476:2521-2543. [PMID: 31409651 DOI: 10.1042/bcj20190383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/09/2019] [Accepted: 08/12/2019] [Indexed: 01/04/2023]
Abstract
DHX8 is a crucial DEAH-box RNA helicase involved in splicing and required for the release of mature mRNA from the spliceosome. Here, we report the biochemical characterisation of full-length human DHX8 and the catalytically active helicase core DHX8Δ547, alongside crystal structures of DHX8Δ547 bound to ADP and a structure of DHX8Δ547 bound to poly(A)6 single-strand RNA. Our results reveal that DHX8 has an in vitro binding preference for adenine-rich RNA and that RNA binding triggers the release of ADP through significant conformational flexibility in the conserved DEAH-, P-loop and hook-turn motifs. We demonstrate the importance of R620 and both the hook-turn and hook-loop regions for DHX8 helicase activity and propose that the hook-turn acts as a gatekeeper to regulate the directional movement of the 3' end of RNA through the RNA-binding channel. This study provides an in-depth understanding of the activity of DHX8 and contributes insights into the RNA-unwinding mechanisms of the DEAH-box helicase family.
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Affiliation(s)
- Catarina Felisberto-Rodrigues
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
- Division of Structural Biology, The Institute of Cancer Research, London SW3 6JB, U.K
| | - Jemima C Thomas
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
| | - Craig McAndrew
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
| | - Yann-Vaï Le Bihan
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
- Division of Structural Biology, The Institute of Cancer Research, London SW3 6JB, U.K
| | - Rosemary Burke
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
| | - Paul Workman
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K
| | - Rob L M van Montfort
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London SM2 5NG, U.K.
- Division of Structural Biology, The Institute of Cancer Research, London SW3 6JB, U.K
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25
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Chung CS, Tseng CK, Lai YH, Wang HF, Newman AJ, Cheng SC. Dynamic protein-RNA interactions in mediating splicing catalysis. Nucleic Acids Res 2019; 47:899-910. [PMID: 30395327 PMCID: PMC6344849 DOI: 10.1093/nar/gky1089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/19/2018] [Indexed: 11/16/2022] Open
Abstract
The spliceosome is assembled via sequential interactions of pre-mRNA with five small nuclear RNAs and many proteins. Recent determination of cryo-EM structures for several spliceosomal complexes has provided deep insights into interactions between spliceosomal components and structural changes of the spliceosome between steps, but information on how the proteins interact with pre-mRNA to mediate the reaction is scarce. By systematic analysis of proteins interacting with the splice sites (SSs), we have identified many previously unknown interactions of spliceosomal components with the pre-mRNA. Prp8 directly binds over the 5′SS and the branch site (BS) for the first catalytic step, and the 5′SS and 3′SS for the second step. Switching the Prp8 interaction from the BS to the 3′SS requires Slu7, which interacts dynamically with pre-mRNA first, and then interacts stably with the 3′-exon after Prp16-mediated spliceosome remodeling. Our results suggest that Prp8 plays a key role in positioning the 5′SS and 3′SS, facilitated by Slu7 through interactions with Prp8 and substrate RNA to advance exon ligation. We also provide evidence that Prp16 first docks on the intron 3′ tail, then translocates in the 3′ to 5′ direction on remodeling the spliceosome.
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Affiliation(s)
- Che-Sheng Chung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Chi-Kang Tseng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Yung-Hua Lai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China.,Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan 112, Republic of China
| | - Hui-Fang Wang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China.,Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan 112, Republic of China
| | - Andrew J Newman
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Soo-Chen Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
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26
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Ejaz A, Ordonez H, Jacewicz A, Ferrao R, Shuman S. Structure of mycobacterial 3'-to-5' RNA:DNA helicase Lhr bound to a ssDNA tracking strand highlights distinctive features of a novel family of bacterial helicases. Nucleic Acids Res 2019; 46:442-455. [PMID: 29165676 PMCID: PMC5758891 DOI: 10.1093/nar/gkx1163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/06/2017] [Indexed: 01/17/2023] Open
Abstract
Mycobacterial Lhr is a DNA damage-inducible superfamily 2 helicase that uses adenosine triphosphate (ATP) hydrolysis to drive unidirectional 3′-to-5′ translocation along single-stranded DNA (ssDNA) and to unwind RNA:DNA duplexes en route. ATPase, translocase and helicase activities are encompassed within the N-terminal 856-amino acid segment. The crystal structure of Lhr-(1–856) in complex with AMPPNP•Mg2+ and ssDNA defines a new helicase family. The enzyme comprises two N-terminal RecA-like modules, a winged helix (WH) domain and a unique C-terminal domain. The 3′ ssDNA end binds in a crescent-shaped groove at the interface between the first RecA domain and the WH domain and tracks 5′ into a groove between the second RecA and C domains. A kissing interaction between the second RecA and C domains forms an aperture that demarcates a putative junction between the loading strand tail and the duplex, with the first duplex nucleoside bookended by stacking on Trp597. Intercalation of Ile528 between nucleosides of the loading strand creates another bookend. Coupling of ATP hydrolysis to RNA:DNA unwinding is dependent on Trp597 and Ile528, and on Thr145 and Arg279 that contact phosphates of the loading strand. The structural and functional data suggest a ratchet mechanism of translocation and unwinding coupled to ATP-driven domain movements.
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Affiliation(s)
- Anam Ejaz
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Heather Ordonez
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Agata Jacewicz
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ryan Ferrao
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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27
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Palermo G, Casalino L, Magistrato A, Andrew McCammon J. Understanding the mechanistic basis of non-coding RNA through molecular dynamics simulations. J Struct Biol 2019; 206:267-279. [PMID: 30880083 PMCID: PMC6637970 DOI: 10.1016/j.jsb.2019.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 02/06/2023]
Abstract
Noncoding RNA (ncRNA) has a key role in regulating gene expression, mediating fundamental processes and diseases via a variety of yet unknown mechanisms. Here, we review recent applications of conventional and enhanced Molecular Dynamics (MD) simulations methods to address the mechanistic function of large biomolecular systems that are tightly involved in the ncRNA function and that are of key importance in life sciences. This compendium focuses of three biomolecular systems, namely the CRISPR-Cas9 genome editing machinery, group II intron ribozyme and the ribonucleoprotein complex of the spliceosome, which edit and process ncRNA. We show how the application of a novel accelerated MD simulations method has been key in disclosing the conformational transitions underlying RNA binding in the CRISPR-Cas9 complex, suggesting a mechanism for RNA recruitment and clarifying the conformational changes required for attaining genome editing. As well, we discuss the use of mixed quantum-classical MD simulations in deciphering the catalytic mechanism of RNA splicing as operated by group II intron ribozyme, one of the largest ncRNA structures crystallized so far. Finally, we debate the future challenges and opportunities in the field, discussing the recent application of MD simulations for unraveling the functional biophysics of the spliceosome, a multi-mega Dalton complex of proteins and small nuclear RNAs that performs RNA splicing in humans. This showcase of applications highlights the current talent of MD simulations to dissect atomic-level details of complex biomolecular systems instrumental for the design of finely engineered genome editing machines. As well, this review aims at inspiring future investigations of several other ncRNA regulatory systems, such as micro and small interfering RNAs, which achieve their function and specificity using RNA-based recognition and targeting strategies.
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Affiliation(s)
- Giulia Palermo
- Department of Bioengineering, Bourns College of Engineering, University of California Riverside, 900 University Avenue, Riverside, CA 92521, United States.
| | - Lorenzo Casalino
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, United States
| | - Alessandra Magistrato
- Consiglio Nazionale delle Ricerche-Istituto Officina dei Materiali, Democritos National Simulation Center c/o International School for Advanced Studies (SISSA), 34136 Trieste, Italy
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, United States; Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, United States; National Biomedical Computation Resource, University of California San Diego, La Jolla, CA 92093, United States
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28
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Pattabhi S, Knoll ML, Gale M, Loo YM. DHX15 Is a Coreceptor for RLR Signaling That Promotes Antiviral Defense Against RNA Virus Infection. J Interferon Cytokine Res 2019; 39:331-346. [PMID: 31090472 PMCID: PMC6590726 DOI: 10.1089/jir.2018.0163] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/01/2019] [Indexed: 12/23/2022] Open
Abstract
RNA helicases play an important role in the response to microbial infection. Retinoic acid inducible gene-I (RIG-I) and members of the RIG-I-like receptor (RLR) family of helicases function as cytoplasmic pattern recognition receptors (PRRs) whose actions are essential for recognition of RNA viruses. RIG-I association with pathogen-associated molecular patterns (PAMPs) within viral RNA leads to its activation and signaling via the mitochondrial antiviral signaling (MAVS) adapter protein. This interaction mediates downstream signaling events that drive the innate immune response to virus infection. Here we identify the DEAH-box RNA helicase DHX15 as a RLR binding partner and signaling cofactor. In human cells, DHX15 is required for virus-induced RLR signaling of innate immune gene expression. Knockdown of DHX15 increased susceptibility to infection by RNA viruses of diverse genera, including Paramyxoviridae, Rhabdoviridae, and Picornaviridae. DHX15 associates with RIG-I caspase activation and recruitment domains (CARDs) through its amino terminus, in which the complex is recruited to MAVS on virus infection. Importantly, although DHX15 cannot substitute for RIG-I in innate immune signaling, DHX15 selectively binds PAMP RNA to promote RIG-I ATP hydrolysis and signaling activation in response to viral RNA. Our results define DHX15 as a coreceptor required for RLR innate immune responses to control RNA virus infection.
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Affiliation(s)
- Sowmya Pattabhi
- Department of Global Health, University of Washington, Seattle, Washington
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
| | - Megan L. Knoll
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
| | - Michael Gale
- Department of Global Health, University of Washington, Seattle, Washington
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
| | - Yueh-Ming Loo
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
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29
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Wollenhaupt J, Henning LM, Sticht J, Becke C, Freund C, Santos KF, Wahl MC. Intrinsically Disordered Protein Ntr2 Modulates the Spliceosomal RNA Helicase Brr2. Biophys J 2019; 114:788-799. [PMID: 29490241 DOI: 10.1016/j.bpj.2017.12.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/05/2017] [Accepted: 12/27/2017] [Indexed: 11/30/2022] Open
Abstract
Precursor messenger RNA splicing is mediated by the spliceosome, a large and dynamic molecular machine composed of five small nuclear RNAs and numerous proteins. Many spliceosomal proteins are predicted to be intrinsically disordered or contain large disordered regions, but experimental validation of these predictions is scarce, and the precise functions of these proteins are often unclear. Here, we show via circular dichroism spectroscopy, dynamic light scattering, and NMR spectroscopy that the yeast spliceosomal disassembly factor Ntr2 is largely intrinsically disordered. Peptide SPOT analyses, analytical size-exclusion chromatography, and surface plasmon resonance measurements revealed that Ntr2 uses an N-terminal region to bind the C-terminal helicase unit of the Brr2 RNA helicase, an enzyme involved in spliceosome activation and implicated in splicing catalysis and spliceosome disassembly. NMR analyses suggested that Ntr2 does not adopt a tertiary structure and likely remains disordered upon complex formation. RNA binding and unwinding studies showed that Ntr2 downregulates Brr2 helicase activity in vitro by modulating the fraction of helicase molecules productively bound to the RNA substrate. Our data clarify the nature of a physical link between Brr2 and Ntr2, and point to the possibility of a functional Ntr2-Brr2 interplay during splicing.
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Affiliation(s)
- Jan Wollenhaupt
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Lisa M Henning
- Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Jana Sticht
- Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany; Core Facility BioSupraMol, Freie Universität Berlin, Berlin, Germany
| | - Christian Becke
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Karine F Santos
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany.
| | - Markus C Wahl
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany; Macromolecular Crystallography, Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany.
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30
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Burke JE, Longhurst AD, Merkurjev D, Sales-Lee J, Rao B, Moresco JJ, Yates JR, Li JJ, Madhani HD. Spliceosome Profiling Visualizes Operations of a Dynamic RNP at Nucleotide Resolution. Cell 2019; 173:1014-1030.e17. [PMID: 29727661 DOI: 10.1016/j.cell.2018.03.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/19/2018] [Accepted: 03/07/2018] [Indexed: 11/28/2022]
Abstract
Tools to understand how the spliceosome functions in vivo have lagged behind advances in the structural biology of the spliceosome. Here, methods are described to globally profile spliceosome-bound pre-mRNA, intermediates, and spliced mRNA at nucleotide resolution. These tools are applied to three yeast species that span 600 million years of evolution. The sensitivity of the approach enables the detection of canonical and non-canonical events, including interrupted, recursive, and nested splicing. This application of statistical modeling uncovers independent roles for the size and position of the intron and the number of introns per transcript in substrate progression through the two catalytic stages. These include species-specific inputs suggestive of spliceosome-transcriptome coevolution. Further investigations reveal the ATP-dependent discard of numerous endogenous substrates after spliceosome assembly in vivo and connect this discard to intron retention, a form of splicing regulation. Spliceosome profiling is a quantitative, generalizable global technology used to investigate an RNP central to eukaryotic gene expression.
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Affiliation(s)
- Jordan E Burke
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Adam D Longhurst
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Daria Merkurjev
- Department of Statistics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jade Sales-Lee
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Beiduo Rao
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - James J Moresco
- Department of Molecular Medicine, the Scripps Research Institute, La Jolla, CA, USA
| | - John R Yates
- Department of Molecular Medicine, the Scripps Research Institute, La Jolla, CA, USA
| | - Jingyi Jessica Li
- Department of Statistics, University of California, Los Angeles, Los Angeles, CA, USA
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA.
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31
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Zhang L, Vielle A, Espinosa S, Zhao R. RNAs in the spliceosome: Insight from cryoEM structures. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1523. [PMID: 30729694 DOI: 10.1002/wrna.1523] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/12/2018] [Accepted: 12/28/2018] [Indexed: 12/28/2022]
Abstract
Pre-mRNA splicing is catalyzed by the spliceosome, a multimegadalton RNA-protein complex. The spliceosome undergoes dramatic compositional and conformational changes through the splicing cycle, forming at least 10 distinct complexes. Recent high-resolution cryoEM structures of various spliceosomal complexes revealed unprecedented details of this large molecular machine. This review highlights insight into the structure and function of the spliceosomal RNA components obtained from these new structures, with a focus on the yeast spliceosome. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Lingdi Zhang
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado
| | - Anne Vielle
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado
| | - Sara Espinosa
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colorado
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32
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Structures of the human spliceosomes before and after release of the ligated exon. Cell Res 2019; 29:274-285. [PMID: 30728453 PMCID: PMC6461851 DOI: 10.1038/s41422-019-0143-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 01/14/2019] [Indexed: 11/08/2022] Open
Abstract
Pre-mRNA splicing is executed by the spliceosome, which has eight major functional states each with distinct composition. Five of these eight human spliceosomal complexes, all preceding exon ligation, have been structurally characterized. In this study, we report the cryo-electron microscopy structures of the human post-catalytic spliceosome (P complex) and intron lariat spliceosome (ILS) at average resolutions of 3.0 and 2.9 Å, respectively. In the P complex, the ligated exon remains anchored to loop I of U5 small nuclear RNA, and the 3′-splice site is recognized by the junction between the 5′-splice site and the branch point sequence. The ATPase/helicase Prp22, along with the ligated exon and eight other proteins, are dissociated in the P-to-ILS transition. Intriguingly, the ILS complex exists in two distinct conformations, one with the ATPase/helicase Prp43 and one without. Comparison of these three late-stage human spliceosomes reveals mechanistic insights into exon release and spliceosome disassembly.
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33
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Excised linear introns regulate growth in yeast. Nature 2019; 565:606-611. [PMID: 30651636 DOI: 10.1038/s41586-018-0828-1] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 11/27/2018] [Indexed: 12/31/2022]
Abstract
Spliceosomal introns are ubiquitous non-coding RNAs that are typically destined for rapid debranching and degradation. Here we describe 34 excised introns in Saccharomyces cerevisiae that-despite being rapidly degraded in log-phase growth-accumulate as linear RNAs under either saturated-growth conditions or other stresses that cause prolonged inhibition of TORC1, which is a key integrator of growth signalling. Introns that become stabilized remain associated with components of the spliceosome and differ from other spliceosomal introns in having a short distance between their lariat branch point and 3' splice site, which is necessary and sufficient for their stabilization. Deletion of these unusual introns is disadvantageous in saturated conditions and causes aberrantly high growth rates in yeast that are chronically challenged with the TORC1 inhibitor rapamycin. The reintroduction of native or engineered stable introns suppresses this aberrant rapamycin response. Thus, excised introns function within the TOR growth-signalling network of S. cerevisiae and, more generally, excised spliceosomal introns can have biological functions.
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Pietrzyk-Brzezinska AJ, Absmeier E, Klauck E, Wen Y, Antelmann H, Wahl MC. Crystal Structure of the Escherichia coli DExH-Box NTPase HrpB. Structure 2018; 26:1462-1473.e4. [PMID: 30174149 DOI: 10.1016/j.str.2018.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/27/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
Abstract
Eukaryotic DExH-box proteins are important post-transcriptional gene regulators, many of which employ RNA-stimulated nucleoside triphosphatase activity to remodel RNAs or ribonucleoprotein complexes. However, bacterial DExH-box proteins are structurally and functionally poorly characterized. We report the crystal structure of the Escherichia coli DExH-box protein HrpB. A globular head is composed of dual RecA, winged-helix, helical bundle and oligonucleotide/oligosaccharide-binding domains, resembling a compact version of eukaryotic DExH-box proteins. Additionally, HrpB harbors a C-terminal region not found in proteins with known structure, which bestows the protein with unique interaction potential. Interaction and activity assays showed that the protein binds RNA but not DNA, hydrolyzes all nucleoside triphosphates in an RNA-stimulated manner, but does not unwind diverse model RNAs in vitro. These observations can be rationalized by detailed comparisons with structurally characterized eukaryotic DExH-box proteins. Comparative phenotypic analyses of an E. coli hrpB knockout mutant suggested diverse functions of HrpB homologs in different bacteria.
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Affiliation(s)
| | - Eva Absmeier
- Freie Universität Berlin, Laboratory of Structural Biochemistry, 14195 Berlin, Germany
| | - Eberhard Klauck
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Yanlin Wen
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Haike Antelmann
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Markus C Wahl
- Freie Universität Berlin, Laboratory of Structural Biochemistry, 14195 Berlin, Germany; Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, 12489 Berlin, Germany.
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All-atom simulations disentangle the functional dynamics underlying gene maturation in the intron lariat spliceosome. Proc Natl Acad Sci U S A 2018; 115:6584-6589. [PMID: 29891649 DOI: 10.1073/pnas.1802963115] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The spliceosome (SPL) is a majestic macromolecular machinery composed of five small nuclear RNAs and hundreds of proteins. SPL removes noncoding introns from precursor messenger RNAs (pre-mRNAs) and ligates coding exons, giving rise to functional mRNAs. Building on the first SPL structure solved at near-atomic-level resolution, here we elucidate the functional dynamics of the intron lariat spliceosome (ILS) complex through multi-microsecond-long molecular-dynamics simulations of ∼1,000,000 atoms models. The ILS essential dynamics unveils (i) the leading role of the Spp42 protein, which heads the gene maturation by tuning the motions of distinct SPL components, and (ii) the critical participation of the Cwf19 protein in displacing the intron lariat/U2 branch helix. These findings provide unprecedented details on the SPL functional dynamics, thus contributing to move a step forward toward a thorough understanding of eukaryotic pre-mRNA splicing.
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Su YL, Chen HC, Tsai RT, Lin PC, Cheng SC. Cwc23 is a component of the NTR complex and functions to stabilize Ntr1 and facilitate disassembly of spliceosome intermediates. Nucleic Acids Res 2018; 46:3764-3773. [PMID: 29390077 PMCID: PMC6044358 DOI: 10.1093/nar/gky052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 01/22/2023] Open
Abstract
Cwc23 is a member of the J protein family, and has been shown to interact with Ntr1, a scaffold protein that interacts with Ntr2 and Prp43 to form the NTR complex that mediates spliceosome disassembly. We show that Cwc23 is also an intrinsic component of the NTR complex, and that it interacts with the carboxyl terminus of Ntr1. Metabolic depletion of Cwc23 concurrently depleted Ntr1 and Ntr2, suggesting a role for Cwc23 in stabilizing these two proteins. Ntr1, Ntr2 and Cwc23 are stoichiometrically balanced, and form a stable heterotrimer. Depletion of Cwc23 from splicing extracts using antibodies resulted in depletion of all three proteins and accumulation of intron-lariat in the splicing reaction. Cwc23 is not required for disassembly of intron-lariat spliceosome (ILS), but facilitates disassembly of spliceosome intermediates after the actions of Prp2 and Prp16 by stabilizing the association of Ntr1 with the spliceosome. Cwc23 has a more limited effect on the association of Ntr1 with the ILS. Our data suggest that Cwc23 is important for maintaining the levels of Ntr1 and Ntr2, and that it also plays a regulatory role in targeting spliceosome intermediates for disassembly.
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Affiliation(s)
- Yu-Lun Su
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Hsin-Chou Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Rong-Tzong Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Pei-Chun Lin
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Soo-Chen Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115, Republic of China
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37
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Didychuk AL, Butcher SE, Brow DA. The life of U6 small nuclear RNA, from cradle to grave. RNA (NEW YORK, N.Y.) 2018; 24:437-460. [PMID: 29367453 PMCID: PMC5855946 DOI: 10.1261/rna.065136.117] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Removal of introns from precursor messenger RNA (pre-mRNA) and some noncoding transcripts is an essential step in eukaryotic gene expression. In the nucleus, this process of RNA splicing is carried out by the spliceosome, a multi-megaDalton macromolecular machine whose core components are conserved from yeast to humans. In addition to many proteins, the spliceosome contains five uridine-rich small nuclear RNAs (snRNAs) that undergo an elaborate series of conformational changes to correctly recognize the splice sites and catalyze intron removal. Decades of biochemical and genetic data, along with recent cryo-EM structures, unequivocally demonstrate that U6 snRNA forms much of the catalytic core of the spliceosome and is highly dynamic, interacting with three snRNAs, the pre-mRNA substrate, and >25 protein partners throughout the splicing cycle. This review summarizes the current state of knowledge on how U6 snRNA is synthesized, modified, incorporated into snRNPs and spliceosomes, recycled, and degraded.
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Affiliation(s)
- Allison L Didychuk
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Samuel E Butcher
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - David A Brow
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706, USA
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Bao P, Will CL, Urlaub H, Boon KL, Lührmann R. The RES complex is required for efficient transformation of the precatalytic B spliceosome into an activated B act complex. Genes Dev 2018; 31:2416-2429. [PMID: 29330354 PMCID: PMC5795787 DOI: 10.1101/gad.308163.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/11/2017] [Indexed: 12/31/2022]
Abstract
The precise function of the trimeric retention and splicing (RES) complex in pre-mRNA splicing remains unclear. Here we dissected the role of RES during the assembly and activation of yeast spliceosomes. The efficiency of pre-mRNA splicing was significantly lower in the absence of the RES protein Snu17, and the recruitment of its binding partners, Pml1 (pre-mRNA leakage protein 1) and Bud13 (bud site selection protein 13), to the spliceosome was either abolished or substantially reduced. RES was not required for the assembly of spliceosomal B complexes, but its absence hindered efficient Bact complex formation. ΔRES spliceosomes were no longer strictly dependent on Prp2 activity for their catalytic activation, suggesting that they are structurally compromised. Addition of Prp2, Spp2, and UTP to affinity-purified ΔRES B or a mixture of B/Bact complexes formed on wild-type pre-mRNA led to their disassembly. However, no substantial disassembly was observed with ΔRES spliceosomes formed on a truncated pre-mRNA that allows Prp2 binding but blocks its activity. Thus, in the absence of RES, Prp2 appears to bind prematurely, leading to the disassembly of the ΔRES B complexes to which it binds. Our data suggest that Prp2 can dismantle B complexes with an aberrant protein composition, suggesting that it may proofread the spliceosome's RNP structure prior to activation.
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Affiliation(s)
- Penghui Bao
- 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
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, D-37075 Göttingen, Germany
| | - Kum-Loong Boon
- Department of Cellular Biochemistry, 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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Bai R, Yan C, Wan R, Lei J, Shi Y. Structure of the Post-catalytic Spliceosome from Saccharomyces cerevisiae. Cell 2017; 171:1589-1598.e8. [PMID: 29153833 DOI: 10.1016/j.cell.2017.10.038] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/12/2017] [Accepted: 10/23/2017] [Indexed: 01/02/2023]
Abstract
Removal of an intron from a pre-mRNA by the spliceosome results in the ligation of two exons in the post-catalytic spliceosome (known as the P complex). Here, we present a cryo-EM structure of the P complex from Saccharomyces cerevisiae at an average resolution of 3.6 Å. The ligated exon is held in the active site through RNA-RNA contacts. Three bases at the 3' end of the 5' exon remain anchored to loop I of U5 small nuclear RNA, and the conserved AG nucleotides of the 3'-splice site (3'SS) are specifically recognized by the invariant adenine of the branch point sequence, the guanine base at the 5' end of the 5'SS, and an adenine base of U6 snRNA. The 3'SS is stabilized through an interaction with the 1585-loop of Prp8. The P complex structure provides a view on splice junction formation critical for understanding the complete splicing cycle.
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Affiliation(s)
- Rui Bai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Ruixue Wan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jianlin Lei
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China; Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China; Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Shilongshan Road No. 18, Xihu District, Hangzhou 310064, Zhejiang Province, China.
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40
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De Novo Missense Mutations in DHX30 Impair Global Translation and Cause a Neurodevelopmental Disorder. Am J Hum Genet 2017; 101:716-724. [PMID: 29100085 DOI: 10.1016/j.ajhg.2017.09.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 09/19/2017] [Indexed: 11/21/2022] Open
Abstract
DHX30 is a member of the family of DExH-box helicases, which use ATP hydrolysis to unwind RNA secondary structures. Here we identified six different de novo missense mutations in DHX30 in twelve unrelated individuals affected by global developmental delay (GDD), intellectual disability (ID), severe speech impairment and gait abnormalities. While four mutations are recurrent, two are unique with one affecting the codon of one recurrent mutation. All amino acid changes are located within highly conserved helicase motifs and were found to either impair ATPase activity or RNA recognition in different in vitro assays. Moreover, protein variants exhibit an increased propensity to trigger stress granule (SG) formation resulting in global translation inhibition. Thus, our findings highlight the prominent role of translation control in development and function of the central nervous system and also provide molecular insight into how DHX30 dysfunction might cause a neurodevelopmental disorder.
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41
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Asselin-Mullen P, Chauvin A, Dubois ML, Drissi R, Lévesque D, Boisvert FM. Protein interaction network of alternatively spliced NudCD1 isoforms. Sci Rep 2017; 7:12987. [PMID: 29021621 PMCID: PMC5636827 DOI: 10.1038/s41598-017-13441-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 09/25/2017] [Indexed: 12/16/2022] Open
Abstract
NudCD1, also known as CML66 or OVA66, is a protein initially identified as overexpressed in patients with chronic myelogenous leukemia. The mRNA of NudCD1 is expressed in heart and testis of normal tissues, and is overexpressed in several cancers. Previous studies have shown that the expression level of the protein correlates with tumoral phenotype, possibly interacting upstream of the Insulin Growth Factor - 1 Receptor (IGF-1R). The gene encoding the NudCD1 protein consists of 12 exons that can be alternative spliced, leading to the expression of three different isoforms. These isoforms possess a common region of 492 amino acids in their C-terminus region and have an isoform specific N-terminus. To determine the distinct function of each isoforms, we have localised the isoforms within the cells using immunofluorescence microscopy and used a quantitative proteomics approach (SILAC) to identify specific protein interaction partners for each isoforms. Localization studies showed a different subcellular distribution for the different isoforms, with the first isoform being nuclear, while the other two isoforms have distinct cytoplasmic and nuclear location. We found that the different NudCD1 isoforms have unique interacting partners, with the first isoform binding to a putative RNA helicase named DHX15 involved in mRNA splicing.
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Affiliation(s)
- Patrick Asselin-Mullen
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Anaïs Chauvin
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Marie-Line Dubois
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Romain Drissi
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Dominique Lévesque
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - François-Michel Boisvert
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada.
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Wan R, Yan C, Bai R, Lei J, Shi Y. Structure of an Intron Lariat Spliceosome from Saccharomyces cerevisiae. Cell 2017; 171:120-132.e12. [PMID: 28919079 DOI: 10.1016/j.cell.2017.08.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/07/2017] [Accepted: 08/15/2017] [Indexed: 12/25/2022]
Abstract
The disassembly of the intron lariat spliceosome (ILS) marks the end of a splicing cycle. Here we report a cryoelectron microscopy structure of the ILS complex from Saccharomyces cerevisiae at an average resolution of 3.5 Å. The intron lariat remains bound in the spliceosome whereas the ligated exon is already dissociated. The step II splicing factors Prp17 and Prp18, along with Cwc21 and Cwc22 that stabilize the 5' exon binding to loop I of U5 small nuclear RNA (snRNA), have been released from the active site assembly. The DEAH family ATPase/helicase Prp43 binds Syf1 at the periphery of the spliceosome, with its RNA-binding site close to the 3' end of U6 snRNA. The C-terminal domain of Ntr1/Spp382 associates with the GTPase Snu114, and Ntr2 is anchored to Prp8 while interacting with the superhelical domain of Ntr1. These structural features suggest a plausible mechanism for the disassembly of the ILS complex.
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Affiliation(s)
- Ruixue Wan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Rui Bai
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jianlin Lei
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China; Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China; Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Shilongshan Road No. 18, Xihu District, Hangzhou 310064, Zhejiang Province, China.
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Carrocci TJ, Zoerner DM, Paulson JC, Hoskins AA. SF3b1 mutations associated with myelodysplastic syndromes alter the fidelity of branchsite selection in yeast. Nucleic Acids Res 2017; 45:4837-4852. [PMID: 28062854 PMCID: PMC5416834 DOI: 10.1093/nar/gkw1349] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/22/2016] [Indexed: 12/19/2022] Open
Abstract
RNA and protein components of the spliceosome work together to identify the 5΄ splice site, the 3΄ splice site, and the branchsite (BS) of nascent pre-mRNA. SF3b1 plays a key role in recruiting the U2 snRNP to the BS. Mutations in human SF3b1 have been linked to many diseases such as myelodysplasia (MDS) and cancer. We have used SF3b1 mutations associated with MDS to interrogate the role of the yeast ortholog, Hsh155, in BS selection and splicing. These alleles change how the spliceosome recognizes the BS and alter splicing when nonconsensus nucleotides are present at the −2, −1 and +1 positions relative to the branchpoint adenosine. This indicates that changes in BS usage observed in humans with SF3b1 mutations may result from perturbation of a conserved mechanism of BS recognition. Notably, different HSH155 alleles elicit disparate effects on splicing: some increase the fidelity of BS selection while others decrease fidelity. Our data support a model wherein conformational changes in SF3b1 promote U2 association with the BS independently of the action of the DEAD-box ATPase Prp5. We propose that SF3b1 functions to stabilize weak U2/BS duplexes to drive spliceosome assembly and splicing.
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Affiliation(s)
- Tucker J Carrocci
- Department of Biochemistry, U. Wisconsin-Madison, Madison, WI 53706, USA
| | - Douglas M Zoerner
- Department of Biochemistry, U. Wisconsin-Madison, Madison, WI 53706, USA
| | - Joshua C Paulson
- Department of Biochemistry, U. Wisconsin-Madison, Madison, WI 53706, USA
| | - Aaron A Hoskins
- Department of Biochemistry, U. Wisconsin-Madison, Madison, WI 53706, USA
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Chen Z, Gui B, Zhang Y, Xie G, Li W, Liu S, Xu B, Wu C, He L, Yang J, Yi X, Yang X, Sun L, Liang J, Shang Y. Identification of a 35S U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP) complex intermediate in spliceosome assembly. J Biol Chem 2017; 292:18113-18128. [PMID: 28878014 DOI: 10.1074/jbc.m117.797357] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/28/2017] [Indexed: 11/06/2022] Open
Abstract
The de novo assembly and post-splicing reassembly of the U4/U6.U5 tri-snRNP remain to be investigated. We report here that ZIP, a protein containing a CCCH-type zinc finger and a G-patch domain, as characterized by us previously, regulates pre-mRNA splicing independent of RNA binding. We found that ZIP physically associates with the U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP). Remarkably, the ZIP-containing tri-snRNP, which has a sedimentation coefficient of ∼35S, is a tri-snRNP that has not been described previously. We also found that the 35S tri-snRNP contains hPrp24, indicative of a state in which the U4/U6 di-snRNP is integrating with the U5 snRNP. We found that the 35S tri-snRNP is enriched in the Cajal body, indicating that it is an assembly intermediate during 25S tri-snRNP maturation. We showed that the 35S tri-snRNP also contains hPrp43, in which ATPase/RNA helicase activities are stimulated by ZIP. Our study identified, for the first time, a tri-snRNP intermediate, shedding new light on the de novo assembly and recycling of the U4/U6.U5 tri-snRNP.
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Affiliation(s)
- Zhe Chen
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bin Gui
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yu Zhang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Guojia Xie
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wanjin Li
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Shumeng Liu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bosen Xu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Chongyang Wu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Lin He
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jianguo Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xia Yi
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohan Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Luyang Sun
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Liang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yongfeng Shang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China, .,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China, and.,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
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45
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Fourmann JB, Tauchert MJ, Ficner R, Fabrizio P, Lührmann R. Regulation of Prp43-mediated disassembly of spliceosomes by its cofactors Ntr1 and Ntr2. Nucleic Acids Res 2017; 45:4068-4080. [PMID: 27923990 PMCID: PMC5397206 DOI: 10.1093/nar/gkw1225] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/22/2016] [Indexed: 12/18/2022] Open
Abstract
The DEAH-box NTPase Prp43 disassembles spliceosomes in co-operation with the cofactors Ntr1/Spp382 and Ntr2, forming the NTR complex. How Prp43 is regulated by its cofactors to discard selectively only intron-lariat spliceosomes (ILS) and defective spliceosomes and to prevent disassembly of earlier and properly assembled/wild-type spliceosomes remains unclear. First, we show that Ntr1΄s G-patch motif (Ntr1GP) can be replaced by the GP motif of Pfa1/Sqs1, a Prp43΄s cofactor in ribosome biogenesis, demonstrating that the specific function of Ntr1GP is to activate Prp43 for spliceosome disassembly and not to guide Prp43 to its binding site in the spliceosome. Furthermore, we show that Ntr1΄s C-terminal domain (CTD) plays a safeguarding role by preventing Prp43 from disrupting wild-type spliceosomes other than the ILS. Ntr1 and Ntr2 can also discriminate between wild-type and defective spliceosomes. In both type of spliceosomes, Ntr1-CTD impedes Prp43-mediated disassembly while the Ntr1GP promotes disassembly. Intriguingly, Ntr2 plays a specific role in defective spliceosomes, likely by stabilizing Ntr1 and allowing Prp43 to enter a productive interaction with the GP motif of Ntr1. Our data indicate that Ntr1 and Ntr2 act as ‘doorkeepers’ and suggest that both cofactors inspect the RNP structure of spliceosomal complexes thereby targeting suboptimal spliceosomes for Prp43-mediated disassembly.
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Affiliation(s)
- Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - Marcel J Tauchert
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg August University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg August University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen, Germany
| | - Patrizia Fabrizio
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
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He Y, Staley JP, Andersen GR, Nielsen KH. Structure of the DEAH/RHA ATPase Prp43p bound to RNA implicates a pair of hairpins and motif Va in translocation along RNA. RNA (NEW YORK, N.Y.) 2017; 23:1110-1124. [PMID: 28416566 PMCID: PMC5473145 DOI: 10.1261/rna.060954.117] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Three families of nucleic acid-dependent ATPases (DEAH/RHA, Ski2-like, and NS3/NPH-II), termed the DExH ATPases, are thought to execute myriad functions by processive, ATP-dependent, 3' to 5' translocation along single-stranded nucleic acid. While the mechanism of translocation of the viral NS3/NPH-II family has been studied extensively, it has not been clear if or how the principles that have emerged for this family extend to the other two families. Here we report the crystal structure of the yeast DEAH/RHA family ATPase Prp43p, which functions in splicing and ribosome biogenesis, in complex with poly-uracil and a nonhydrolyzable ATP analog. The structure reveals a conserved DEAH/RHA-specific variation of motif Ib within the RecA1 domain of the catalytic core, in which the motif elongates as a β-hairpin that bookends the 3' end of a central RNA stack, a function that in the viral and Ski-2 families is performed by an auxiliary domain. Supporting a fundamental role in translocation, mutations in this hairpin abolished helicase activity without affecting RNA binding or ATPase activity. While the structure reveals differences with viral ATPases in the RecA1 domain, our structure demonstrates striking similarities with viral ATPases in the RecA2 domain of the catalytic core, including both a prominent β-hairpin that bookends the 5' end of the RNA stack and a dynamic motif Va that is implicated in mediating translocation. Our crystal structure, genetic, and biochemical experiments, as well as comparisons with other DExH ATPases, support a generalized mechanism for the DExH class of helicases involving a pair of bookends that inchworm along RNA.
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Affiliation(s)
- Yangzi He
- Department of Molecular Biology and Genetics, Aarhus University, DK8000 Aarhus C, Denmark
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637, USA
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, DK8000 Aarhus C, Denmark
| | - Klaus H Nielsen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637, USA
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47
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The genomic landscape of core-binding factor acute myeloid leukemias. Nat Genet 2016; 48:1551-1556. [PMID: 27798625 DOI: 10.1038/ng.3709] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/03/2016] [Indexed: 12/15/2022]
Abstract
Acute myeloid leukemia (AML) comprises a heterogeneous group of leukemias frequently defined by recurrent cytogenetic abnormalities, including rearrangements involving the core-binding factor (CBF) transcriptional complex. To better understand the genomic landscape of CBF-AMLs, we analyzed both pediatric (n = 87) and adult (n = 78) samples, including cases with RUNX1-RUNX1T1 (n = 85) or CBFB-MYH11 (n = 80) rearrangements, by whole-genome or whole-exome sequencing. In addition to known mutations in the Ras pathway, we identified recurrent stabilizing mutations in CCND2, suggesting a previously unappreciated cooperating pathway in CBF-AML. Outside of signaling alterations, RUNX1-RUNX1T1 and CBFB-MYH11 AMLs demonstrated remarkably different spectra of cooperating mutations, as RUNX1-RUNX1T1 cases harbored recurrent mutations in DHX15 and ZBTB7A, as well as an enrichment of mutations in epigenetic regulators, including ASXL2 and the cohesin complex. This detailed analysis provides insights into the pathogenesis and development of CBF-AML, while highlighting dramatic differences in the landscapes of cooperating mutations for these related AML subtypes.
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Aw J, Shen Y, Wilm A, Sun M, Lim X, Boon KL, Tapsin S, Chan YS, Tan CP, Sim A, Zhang T, Susanto T, Fu Z, Nagarajan N, Wan Y. In Vivo Mapping of Eukaryotic RNA Interactomes Reveals Principles of Higher-Order Organization and Regulation. Mol Cell 2016; 62:603-17. [DOI: 10.1016/j.molcel.2016.04.028] [Citation(s) in RCA: 226] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/07/2016] [Accepted: 04/22/2016] [Indexed: 01/01/2023]
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Fourmann JB, Dybkov O, Agafonov DE, Tauchert MJ, Urlaub H, Ficner R, Fabrizio P, Lührmann R. The target of the DEAH-box NTP triphosphatase Prp43 in Saccharomyces cerevisiae spliceosomes is the U2 snRNP-intron interaction. eLife 2016; 5. [PMID: 27115347 PMCID: PMC4866824 DOI: 10.7554/elife.15564] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/25/2016] [Indexed: 12/19/2022] Open
Abstract
The DEAH-box NTPase Prp43 and its cofactors Ntr1 and Ntr2 form the NTR complex and are required for disassembling intron-lariat spliceosomes (ILS) and defective earlier spliceosomes. However, the Prp43 binding site in the spliceosome and its target(s) are unknown. We show that Prp43 fused to Ntr1's G-patch motif (Prp43_Ntr1GP) is as efficient as the NTR in ILS disassembly, yielding identical dissociation products and recognizing its natural ILS target even in the absence of Ntr1’s C-terminal-domain (CTD) and Ntr2. Unlike the NTR, Prp43_Ntr1GP disassembles earlier spliceosomal complexes (A, B, Bact), indicating that Ntr2/Ntr1-CTD prevents NTR from disrupting properly assembled spliceosomes other than the ILS. The U2 snRNP-intron interaction is disrupted in all complexes by Prp43_Ntr1GP, and in the spliceosome contacts U2 proteins and the pre-mRNA, indicating that the U2 snRNP-intron interaction is Prp43’s major target. DOI:http://dx.doi.org/10.7554/eLife.15564.001
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Affiliation(s)
- Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Olexandr Dybkov
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dmitry E Agafonov
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Marcel J Tauchert
- Department of Molecular Structure Biology, Institute for Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Bionalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany.,Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structure Biology, Institute for Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Patrizia Fabrizio
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
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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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