1
|
Hu Y, Lopez VA, Xu H, Pfister JP, Song B, Servage KA, Sakurai M, Jones BT, Mendell JT, Wang T, Wu J, Lambowitz AM, Tomchick DR, Pawłowski K, Tagliabracci VS. Biochemical and structural insights into a 5' to 3' RNA ligase reveal a potential role in tRNA ligation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590974. [PMID: 38712170 PMCID: PMC11071452 DOI: 10.1101/2024.04.24.590974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
ATP-grasp superfamily enzymes contain a hand-like ATP-binding fold and catalyze a variety of reactions using a similar catalytic mechanism. More than 30 protein families are categorized in this superfamily, and they are involved in a plethora of cellular processes and human diseases. Here we identify C12orf29 as an atypical ATP-grasp enzyme that ligates RNA. Human C12orf29 and its homologs auto-adenylate on an active site Lys residue as part of a reaction intermediate that specifically ligates RNA halves containing a 5'-phosphate and a 3'-hydroxyl. C12orf29 binds tRNA in cells and can ligate tRNA within the anticodon loop in vitro. Genetic depletion of c12orf29 in female mice alters global tRNA levels in brain. Furthermore, crystal structures of a C12orf29 homolog from Yasminevirus bound to nucleotides reveal a minimal and atypical RNA ligase fold with a unique active site architecture that participates in catalysis. Collectively, our results identify C12orf29 as an RNA ligase and suggest its involvement in tRNA biology.
Collapse
Affiliation(s)
- Yingjie Hu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Victor A. Lopez
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Hengyi Xu
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, Texas 78712, USA
| | - James P. Pfister
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Bing Song
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kelly A. Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Masahiro Sakurai
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Benjamin T. Jones
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Joshua T. Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Tao Wang
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Jun Wu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynecology, Children’s Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Alan M. Lambowitz
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, Texas 78712, USA
| | - Diana R. Tomchick
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Krzysztof Pawłowski
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Vincent S. Tagliabracci
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| |
Collapse
|
2
|
Liu P, Zhang R, Song X, Tian X, Guan Y, Li L, He M, He C, Ding N. RTCB deficiency triggers colitis in mice by influencing the NF-κB and Wnt/β-catenin signaling pathways. Acta Biochim Biophys Sin (Shanghai) 2024; 56:405-413. [PMID: 38425245 PMCID: PMC11292128 DOI: 10.3724/abbs.2023279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/25/2023] [Indexed: 03/02/2024] Open
Abstract
RNA terminal phosphorylase B (RTCB) has been shown to play a significant role in multiple physiological processes. However, the specific role of RTCB in the mouse colon remains unclear. In this study, we employ a conditional knockout mouse model to investigate the effects of RTCB depletion on the colon and the potential molecular mechanisms. We assess the efficiency and phenotype of Rtcb knockout using PCR, western blot analysis, histological staining, and immunohistochemistry. Compared with the control mice, the Rtcb-knockout mice exhibit compromised colonic barrier integrity and prominent inflammatory cell infiltration. In the colonic tissues of Rtcb-knockout mice, the protein levels of TNF-α, IL-8, and p-p65 are increased, whereas the levels of IKKβ and IκBα are decreased. Moreover, the level of GSK3β is increased, whereas the levels of Wnt3a, β-catenin, and LGR5 are decreased. Collectively, our findings unveil a close association between RTCB and colonic tissue homeostasis and demonstrate that RTCB deficiency can lead to dysregulation of both the NF-κB and Wnt/β-catenin signaling pathways in colonic cells.
Collapse
Affiliation(s)
- Peiyan Liu
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Ruitao Zhang
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Xiaotong Song
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Xiaohua Tian
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Yichao Guan
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Licheng Li
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Mei He
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Chengqiang He
- />College of Life ScienceShandong Normal UniversityJinan250014China
| | - Naizheng Ding
- />College of Life ScienceShandong Normal UniversityJinan250014China
| |
Collapse
|
3
|
Ahammed KS, van Hoof A. Fungi of the order Mucorales express a "sealing-only" tRNA ligase. RNA (NEW YORK, N.Y.) 2024; 30:354-366. [PMID: 38307611 PMCID: PMC10946435 DOI: 10.1261/rna.079957.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/20/2024] [Indexed: 02/04/2024]
Abstract
Some eukaryotic pre-tRNAs contain an intron that is removed by a dedicated set of enzymes. Intron-containing pre-tRNAs are cleaved by tRNA splicing endonuclease, followed by ligation of the two exons and release of the intron. Fungi use a "heal and seal" pathway that requires three distinct catalytic domains of the tRNA ligase enzyme, Trl1. In contrast, humans use a "direct ligation" pathway carried out by RTCB, an enzyme completely unrelated to Trl1. Because of these mechanistic differences, Trl1 has been proposed as a promising drug target for fungal infections. To validate Trl1 as a broad-spectrum drug target, we show that fungi from three different phyla contain Trl1 orthologs with all three domains. This includes the major invasive human fungal pathogens, and these proteins can each functionally replace yeast Trl1. In contrast, species from the order Mucorales, including the pathogens Rhizopus arrhizus and Mucor circinelloides, have an atypical Trl1 that contains the sealing domain but lacks both healing domains. Although these species contain fewer tRNA introns than other pathogenic fungi, they still require splicing to decode three of the 61 sense codons. These sealing-only Trl1 orthologs can functionally complement defects in the corresponding domain of yeast Trl1 and use a conserved catalytic lysine residue. We conclude that Mucorales use a sealing-only enzyme together with unidentified nonorthologous healing enzymes for their heal and seal pathway. This implies that drugs that target the sealing activity are more likely to be broader-spectrum antifungals than drugs that target the healing domains.
Collapse
Affiliation(s)
- Khondakar Sayef Ahammed
- Department of Microbiology and Molecular Genetics, UT MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, UT MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas 77030, USA
| |
Collapse
|
4
|
Gerber JL, Morales Guzmán SI, Worf L, Hubbe P, Kopp J, Peschek J. Structural and mechanistic insights into activation of the human RNA ligase RTCB by Archease. Nat Commun 2024; 15:2378. [PMID: 38493148 PMCID: PMC10944509 DOI: 10.1038/s41467-024-46568-2] [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: 06/09/2023] [Accepted: 03/01/2024] [Indexed: 03/18/2024] Open
Abstract
RNA ligases of the RTCB-type play an essential role in tRNA splicing, the unfolded protein response and RNA repair. RTCB is the catalytic subunit of the pentameric human tRNA ligase complex. RNA ligation by the tRNA ligase complex requires GTP-dependent activation of RTCB. This active site guanylylation reaction relies on the activation factor Archease. The mechanistic interplay between both proteins has remained unknown. Here, we report a biochemical and structural analysis of the human RTCB-Archease complex in the pre- and post-activation state. Archease reaches into the active site of RTCB and promotes the formation of a covalent RTCB-GMP intermediate through coordination of GTP and metal ions. During the activation reaction, Archease prevents futile RNA substrate binding to RTCB. Moreover, monomer structures of Archease and RTCB reveal additional states within the RNA ligation mechanism. Taken together, we present structural snapshots along the reaction cycle of the human tRNA ligase.
Collapse
Affiliation(s)
- Janina Lara Gerber
- Heidelberg University, Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | | | - Lorenz Worf
- Heidelberg University, Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Petra Hubbe
- Heidelberg University, Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Jürgen Kopp
- Heidelberg University, Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany
| | - Jirka Peschek
- Heidelberg University, Biochemistry Center (BZH), Im Neuenheimer Feld 328, Heidelberg, Germany.
| |
Collapse
|
5
|
Jaksch D, Irnstorfer J, Kalman PF, Martinez J. Thioredoxin regulates the redox state and the activity of the human tRNA ligase complex. RNA (NEW YORK, N.Y.) 2023; 29:1856-1869. [PMID: 37648453 PMCID: PMC10653391 DOI: 10.1261/rna.079732.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/14/2023] [Indexed: 09/01/2023]
Abstract
The mammalian tRNA ligase complex (tRNA-LC) catalyzes the splicing of intron-containing pre-tRNAs in the nucleus and the splicing of XBP1 mRNA during the unfolded protein response (UPR) in the cytoplasm. We recently reported that the tRNA-LC coevolved with PYROXD1, an essential oxidoreductase that protects the catalytic cysteine of RTCB, the catalytic subunit of the tRNA-LC, against aerobic oxidation. In this study, we show that the oxidoreductase Thioredoxin (TRX) preserves the enzymatic activity of RTCB under otherwise inhibiting concentrations of oxidants. TRX physically interacts with oxidized RTCB, and reduces and reactivates RTCB through the action of its redox-active cysteine pair. We further show that TRX interacts with RTCB at late stages of UPR. Since the interaction requires oxidative conditions, our findings suggest that prolonged UPR generates reactive oxygen species. Thus, our results support a functional role for TRX in securing and repairing the active site of the tRNA-LC, thereby allowing pre-tRNA splicing and UPR to occur when cells encounter mild, but still inhibitory levels of reactive oxygen species.
Collapse
Affiliation(s)
- Dhaarsini Jaksch
- Max Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
- Vienna Biocenter PhD Program, a Doctoral School of the University of Vienna and Medical University of Vienna, 1030 Vienna, Austria
| | - Johanna Irnstorfer
- Max Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Petra-Franziska Kalman
- Max Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Javier Martinez
- Max Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
| |
Collapse
|
6
|
Ahammed KS, van Hoof A. Fungi of the order Mucorales express a "sealing-only" tRNA ligase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567474. [PMID: 38014270 PMCID: PMC10680797 DOI: 10.1101/2023.11.16.567474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Some eukaryotic pre-tRNAs contain an intron that is removed by a dedicated set of enzymes. Intron-containing pre-tRNAs are cleaved by tRNA splicing endonuclease (TSEN), followed by ligation of the two exons and release of the intron. Fungi use a "heal and seal" pathway that requires three distinct catalytic domains of the tRNA ligase enzyme, Trl1. In contrast, humans use a "direct ligation" pathway carried out by RTCB, an enzyme completely unrelated to Trl1. Because of these mechanistic differences, Trl1 has been proposed as a promising drug target for fungal infections. To validate Trl1 as a broad-spectrum drug target, we show that fungi from three different phyla contain Trl1 orthologs with all three domains. This includes the major invasive human fungal pathogens, and these proteins each can functionally replace yeast Trl1. In contrast, species from the order Mucorales, including the pathogens Rhizopus arrhizus and Mucor circinelloides, contain an atypical Trl1 that contains the sealing domain, but lack both healing domains. Although these species contain fewer tRNA introns than other pathogenic fungi, they still require splicing to decode three of the 61 sense codons. These sealing-only Trl1 orthologs can functionally complement defects in the corresponding domain of yeast Trl1 and use a conserved catalytic lysine residue. We conclude that Mucorales use a sealing-only enzyme together with unidentified non-orthologous healing enzymes for their heal and seal pathway. This implies that drugs that target the sealing activity are more likely to be broader-spectrum antifungals than drugs that target the healing domains.
Collapse
Affiliation(s)
- Khondakar Sayef Ahammed
- Department of Microbiology and Molecular Genetics. UT MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences. University of Texas Health Science Center at Houston
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics. UT MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences. University of Texas Health Science Center at Houston
| |
Collapse
|
7
|
Jacewicz A, Dantuluri S, Shuman S. Structural basis for Tpt1-catalyzed 2'-PO 4 transfer from RNA and NADP(H) to NAD . Proc Natl Acad Sci U S A 2023; 120:e2312999120. [PMID: 37883434 PMCID: PMC10622864 DOI: 10.1073/pnas.2312999120] [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: 07/28/2023] [Accepted: 09/14/2023] [Indexed: 10/28/2023] Open
Abstract
Tpt1 is an essential agent of fungal and plant tRNA splicing that removes an internal RNA 2'-phosphate generated by tRNA ligase. Tpt1 also removes the 2'-phosphouridine mark installed by Ark1 kinase in the V-loop of archaeal tRNAs. Tpt1 performs a two-step reaction in which the 2'-PO4 attacks NAD+ to form an RNA-2'-phospho-(ADP-ribose) intermediate, and transesterification of the ADP-ribose O2″ to the RNA 2'-phosphodiester yields 2'-OH RNA and ADP-ribose-1″,2″-cyclic phosphate. Here, we present structures of archaeal Tpt1 enzymes, captured as product complexes with ADP-ribose-1″-PO4, ADP-ribose-2″-PO4, and 2'-OH RNA, and as substrate complexes with 2',5'-ADP and NAD+, that illuminate 2'-PO4 junction recognition and catalysis. We show that archaeal Tpt1 enzymes can use the 2'-PO4-containing metabolites NADP+ and NADPH as substrates for 2'-PO4 transfer to NAD+. A role in 2'-phospho-NADP(H) dynamics provides a rationale for the prevalence of Tpt1 in taxa that lack a capacity for internal RNA 2'-phosphorylation.
Collapse
Affiliation(s)
- Agata Jacewicz
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY10065
| | - Swathi Dantuluri
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY10065
| | - Stewart Shuman
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY10065
| |
Collapse
|
8
|
Saito M, Inose R, Sato A, Tomita M, Suzuki H, Kanai A. Systematic Analysis of Diverse Polynucleotide Kinase Clp1 Family Proteins in Eukaryotes: Three Unique Clp1 Proteins of Trypanosoma brucei. J Mol Evol 2023; 91:669-686. [PMID: 37606665 PMCID: PMC10598085 DOI: 10.1007/s00239-023-10128-x] [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: 03/18/2023] [Accepted: 08/01/2023] [Indexed: 08/23/2023]
Abstract
The Clp1 family proteins, consisting of the Clp1 and Nol9/Grc3 groups, have polynucleotide kinase (PNK) activity at the 5' end of RNA strands and are important enzymes in the processing of some precursor RNAs. However, it remains unclear how this enzyme family diversified in the eukaryotes. We performed a large-scale molecular evolutionary analysis of the full-length genomes of 358 eukaryotic species to classify the diverse Clp1 family proteins. The average number of Clp1 family proteins in eukaryotes was 2.3 ± 1.0, and most representative species had both Clp1 and Nol9/Grc3 proteins, suggesting that the Clp1 and Nol9/Grc3 groups were already formed in the eukaryotic ancestor by gene duplication. We also detected an average of 4.1 ± 0.4 Clp1 family proteins in members of the protist phylum Euglenozoa. For example, in Trypanosoma brucei, there are three genes of the Clp1 group and one gene of the Nol9/Grc3 group. In the Clp1 group proteins encoded by these three genes, the C-terminal domains have been replaced by unique characteristics domains, so we designated these proteins Tb-Clp1-t1, Tb-Clp1-t2, and Tb-Clp1-t3. Experimental validation showed that only Tb-Clp1-t2 has PNK activity against RNA strands. As in this example, N-terminal and C-terminal domain replacement also contributed to the diversification of the Clp1 family proteins in other eukaryotic species. Our analysis also revealed that the Clp1 family proteins in humans and plants diversified through isoforms created by alternative splicing.
Collapse
Affiliation(s)
- Motofumi Saito
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, 252-0882, Japan
| | - Rerina Inose
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
| | - Asako Sato
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, 252-0882, Japan
- Faculty of Environment and Information Studies, Keio University, Fujisawa, 252-0882, Japan
| | - Haruo Suzuki
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan
- Faculty of Environment and Information Studies, Keio University, Fujisawa, 252-0882, Japan
| | - Akio Kanai
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan.
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, 252-0882, Japan.
- Faculty of Environment and Information Studies, Keio University, Fujisawa, 252-0882, Japan.
| |
Collapse
|
9
|
Niu D, Wu Y, Lian J. Circular RNA vaccine in disease prevention and treatment. Signal Transduct Target Ther 2023; 8:341. [PMID: 37691066 PMCID: PMC10493228 DOI: 10.1038/s41392-023-01561-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 06/02/2023] [Accepted: 07/09/2023] [Indexed: 09/12/2023] Open
Abstract
CircRNAs are a class of single-stranded RNAs with covalently linked head-to-tail topology. In the decades since its initial discovery, their biogenesis, regulation, and function have rapidly disclosed, permitting a better understanding and adoption of them as new tools for medical applications. With the development of biotechnology and molecular medicine, artificial circRNAs have been engineered as a novel class of vaccines for disease treatment and prevention. Unlike the linear mRNA vaccine which applications were limited by its instability, inefficiency, and innate immunogenicity, circRNA vaccine which incorporate internal ribosome entry sites (IRESs) and open reading frame (ORF) provides an improved approach to RNA-based vaccination with safety, stability, simplicity of manufacture, and scalability. However, circRNA vaccines are at an early stage, and their optimization, delivery and applications require further development and evaluation. In this review, we comprehensively describe circRNA vaccine, including their history and superiority. We also summarize and discuss the current methodological research for circRNA vaccine preparation, including their design, synthesis, and purification. Finally, we highlight the delivery options of circRNA vaccine and its potential applications in diseases treatment and prevention. Considering their unique high stability, low immunogenicity, protein/peptide-coding capacity and special closed-loop construction, circRNA vaccine, and circRNA-based therapeutic platforms may have superior application prospects in a broad range of diseases.
Collapse
Affiliation(s)
- Dun Niu
- Department of Clinical Laboratory Medicine, Southwest Hospital, Army Medical University (Third Military Medical University), 400038, Chongqing, China
- Department of Clinical Biochemistry, Army Medical University (Third Military Medical University), 400038, Chongqing, China
| | - Yaran Wu
- Department of Clinical Laboratory Medicine, Southwest Hospital, Army Medical University (Third Military Medical University), 400038, Chongqing, China
- Department of Clinical Biochemistry, Army Medical University (Third Military Medical University), 400038, Chongqing, China
| | - Jiqin Lian
- Department of Clinical Laboratory Medicine, Southwest Hospital, Army Medical University (Third Military Medical University), 400038, Chongqing, China.
- Department of Clinical Biochemistry, Army Medical University (Third Military Medical University), 400038, Chongqing, China.
| |
Collapse
|
10
|
Abstract
The study of eukaryotic tRNA processing has given rise to an explosion of new information and insights in the last several years. We now have unprecedented knowledge of each step in the tRNA processing pathway, revealing unexpected twists in biochemical pathways, multiple new connections with regulatory pathways, and numerous biological effects of defects in processing steps that have profound consequences throughout eukaryotes, leading to growth phenotypes in the yeast Saccharomyces cerevisiae and to neurological and other disorders in humans. This review highlights seminal new results within the pathways that comprise the life of a tRNA, from its birth after transcription until its death by decay. We focus on new findings and revelations in each step of the pathway including the end-processing and splicing steps, many of the numerous modifications throughout the main body and anticodon loop of tRNA that are so crucial for tRNA function, the intricate tRNA trafficking pathways, and the quality control decay pathways, as well as the biogenesis and biology of tRNA-derived fragments. We also describe the many interactions of these pathways with signaling and other pathways in the cell.
Collapse
Affiliation(s)
- Eric M Phizicky
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, Ohio State University, Columbus, Ohio 43235, USA
| |
Collapse
|
11
|
Abstract
RNA ligases are present across all forms of life. While enzymatic RNA ligation between 5'-PO4 and 3'-OH termini is prevalent in viruses, fungi, and plants, such RNA ligases are yet to be identified in vertebrates. Here, using a nucleotide-based chemical probe targeting human AMPylated proteome, we have enriched and identified the hitherto uncharacterised human protein chromosome 12 open reading frame 29 (C12orf29) as a human enzyme promoting RNA ligation between 5'-PO4 and 3'-OH termini. C12orf29 catalyses ATP-dependent RNA ligation via a three-step mechanism, involving tandem auto- and RNA AMPylation. Knock-out of C12ORF29 gene impedes the cellular resilience to oxidative stress featuring concurrent RNA degradation, which suggests a role of C12orf29 in maintaining RNA integrity. These data provide the groundwork for establishing a human RNA repair pathway.
Collapse
|
12
|
Sekulovski S, Trowitzsch S. Transfer RNA processing - from a structural and disease perspective. Biol Chem 2022; 403:749-763. [PMID: 35728022 DOI: 10.1515/hsz-2021-0406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/24/2022] [Indexed: 01/05/2023]
Abstract
Transfer RNAs (tRNAs) are highly structured non-coding RNAs which play key roles in translation and cellular homeostasis. tRNAs are initially transcribed as precursor molecules and mature by tightly controlled, multistep processes that involve the removal of flanking and intervening sequences, over 100 base modifications, addition of non-templated nucleotides and aminoacylation. These molecular events are intertwined with the nucleocytoplasmic shuttling of tRNAs to make them available at translating ribosomes. Defects in tRNA processing are linked to the development of neurodegenerative disorders. Here, we summarize structural aspects of tRNA processing steps with a special emphasis on intron-containing tRNA splicing involving tRNA splicing endonuclease and ligase. Their role in neurological pathologies will be discussed. Identification of novel RNA substrates of the tRNA splicing machinery has uncovered functions unrelated to tRNA processing. Future structural and biochemical studies will unravel their mechanistic underpinnings and deepen our understanding of neurological diseases.
Collapse
Affiliation(s)
- Samoil Sekulovski
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt/Main, Germany
| | - Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt/Main, Germany
| |
Collapse
|
13
|
Gerber JL, Köhler S, Peschek J. Eukaryotic tRNA splicing - one goal, two strategies, many players. Biol Chem 2022; 403:765-778. [PMID: 35621519 DOI: 10.1515/hsz-2021-0402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 05/10/2022] [Indexed: 12/28/2022]
Abstract
Transfer RNAs (tRNAs) are transcribed as precursor molecules that undergo several maturation steps before becoming functional for protein synthesis. One such processing mechanism is the enzyme-catalysed splicing of intron-containing pre-tRNAs. Eukaryotic tRNA splicing is an essential process since intron-containing tRNAs cannot fulfil their canonical function at the ribosome. Splicing of pre-tRNAs occurs in two steps: The introns are first excised by a tRNA-splicing endonuclease and the exons are subsequently sealed by an RNA ligase. An intriguing complexity has emerged from newly identified tRNA splicing factors and their interplay with other RNA processing pathways during the past few years. This review summarises our current understanding of eukaryotic tRNA splicing and the underlying enzyme machinery. We highlight recent structural advances and how they have shaped our mechanistic understanding of tRNA splicing in eukaryotic cells. A special focus lies on biochemically distinct strategies for exon-exon ligation in fungi versus metazoans.
Collapse
Affiliation(s)
- Janina L Gerber
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany
| | - Sandra Köhler
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany
| | - Jirka Peschek
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany
| |
Collapse
|
14
|
Ohira T, Minowa K, Sugiyama K, Yamashita S, Sakaguchi Y, Miyauchi K, Noguchi R, Kaneko A, Orita I, Fukui T, Tomita K, Suzuki T. Reversible RNA phosphorylation stabilizes tRNA for cellular thermotolerance. Nature 2022; 605:372-379. [PMID: 35477761 PMCID: PMC9095486 DOI: 10.1038/s41586-022-04677-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/22/2022] [Indexed: 12/30/2022]
Abstract
Post-transcriptional modifications have critical roles in tRNA stability and function1–4. In thermophiles, tRNAs are heavily modified to maintain their thermal stability under extreme growth temperatures5,6. Here we identified 2′-phosphouridine (Up) at position 47 of tRNAs from thermophilic archaea. Up47 confers thermal stability and nuclease resistance to tRNAs. Atomic structures of native archaeal tRNA showed a unique metastable core structure stabilized by Up47. The 2′-phosphate of Up47 protrudes from the tRNA core and prevents backbone rotation during thermal denaturation. In addition, we identified the arkI gene, which encodes an archaeal RNA kinase responsible for Up47 formation. Structural studies showed that ArkI has a non-canonical kinase motif surrounded by a positively charged patch for tRNA binding. A knockout strain of arkI grew slowly at high temperatures and exhibited a synthetic growth defect when a second tRNA-modifying enzyme was depleted. We also identified an archaeal homologue of KptA as an eraser that efficiently dephosphorylates Up47 in vitro and in vivo. Taken together, our findings show that Up47 is a reversible RNA modification mediated by ArkI and KptA that fine-tunes the structural rigidity of tRNAs under extreme environmental conditions. Reversible internal RNA phosphrylation contributes to thermal stability and nuclease resistance of tRNA, and cellular thermotolerance of hyperthermophiles.
Collapse
Affiliation(s)
- Takayuki Ohira
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
| | - Keiichi Minowa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kei Sugiyama
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Seisuke Yamashita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Ryo Noguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Akira Kaneko
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Izumi Orita
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Kozo Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan.
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
| |
Collapse
|
15
|
Peng R, Yoshinari S, Kawano-Sugaya T, Jeelani G, Nozaki T. Identification and Functional Characterization of Divergent 3'-Phosphate tRNA Ligase From Entamoeba histolytica. Front Cell Infect Microbiol 2022; 11:746261. [PMID: 34976851 PMCID: PMC8718801 DOI: 10.3389/fcimb.2021.746261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
HSPC117/RtcB, 3'-phosphate tRNA ligase, is a critical enzyme involved in tRNA splicing and maturation. HSPC117/RtcB is also involved in mRNA splicing of some protein-coding genes including XBP-1. Entamoeba histolytica, a protozoan parasite responsible for human amebiasis, possesses two RtcB proteins (EhRtcB1 and 2), but their biological functions remain unknown. Both RtcBs show kinship with mammalian/archaeal type, and all amino acid residues present in the active sites are highly conserved, as suggested by protein alignment and phylogenetic analyses. EhRtcB1 was demonstrated to be localized to the nucleus, while EhRtcB2 was in the cytosol. EhRtcB1, but not EhRtcB2, was required for optimal growth of E. histolytica trophozoites. Both EhRtcB1 (in cooperation with EhArchease) and EhRtcB2 showed RNA ligation activity in vitro. The predominant role of EhRtcB1 in tRNAIle(UAU) processing in vivo was demonstrated in EhRtcB1- and 2-gene silenced strains. Taken together, we have demonstrated the conservation of tRNA splicing and functional diversification of RtcBs in this amoebozoan lineage.
Collapse
Affiliation(s)
- Ruofan Peng
- Laboratory of Biomedical Chemistry, Department of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shigeo Yoshinari
- Laboratory of Biomedical Chemistry, Department of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tetsuro Kawano-Sugaya
- Laboratory of Biomedical Chemistry, Department of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Ghulam Jeelani
- Laboratory of Biomedical Chemistry, Department of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tomoyoshi Nozaki
- Laboratory of Biomedical Chemistry, Department of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
16
|
Held JP, Feng G, Saunders BR, Pereira CV, Burkewitz K, Patel MR. A tRNA processing enzyme is a key regulator of the mitochondrial unfolded protein response. eLife 2022; 11:71634. [PMID: 35451962 PMCID: PMC9064297 DOI: 10.7554/elife.71634] [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: 06/25/2021] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
The mitochondrial unfolded protein response (UPRmt) has emerged as a predominant mechanism that preserves mitochondrial function. Consequently, multiple pathways likely exist to modulate UPRmt. We discovered that the tRNA processing enzyme, homolog of ELAC2 (HOE-1), is key to UPRmt regulation in Caenorhabditis elegans. We find that nuclear HOE-1 is necessary and sufficient to robustly activate UPRmt. We show that HOE-1 acts via transcription factors ATFS-1 and DVE-1 that are crucial for UPRmt. Mechanistically, we show that HOE-1 likely mediates its effects via tRNAs, as blocking tRNA export prevents HOE-1-induced UPRmt. Interestingly, we find that HOE-1 does not act via the integrated stress response, which can be activated by uncharged tRNAs, pointing toward its reliance on a new mechanism. Finally, we show that the subcellular localization of HOE-1 is responsive to mitochondrial stress and is subject to negative regulation via ATFS-1. Together, we have discovered a novel RNA-based cellular pathway that modulates UPRmt.
Collapse
Affiliation(s)
- James P Held
- Department of Biological Sciences, Vanderbilt UniversityNashvilleUnited States
| | - Gaomin Feng
- Department of Cell and Developmental Biology, Vanderbilt UniversityNashvilleUnited States
| | - Benjamin R Saunders
- Department of Biological Sciences, Vanderbilt UniversityNashvilleUnited States
| | - Claudia V Pereira
- Department of Biological Sciences, Vanderbilt UniversityNashvilleUnited States
| | - Kristopher Burkewitz
- Department of Cell and Developmental Biology, Vanderbilt UniversityNashvilleUnited States
| | - Maulik R Patel
- Department of Biological Sciences, Vanderbilt UniversityNashvilleUnited States,Department of Cell and Developmental Biology, Vanderbilt UniversityNashvilleUnited States,Diabetes Research and Training Center, Vanderbilt University School of MedicineNashvilleUnited States
| |
Collapse
|
17
|
Kroupova A, Ackle F, Asanović I, Weitzer S, Boneberg FM, Faini M, Leitner A, Chui A, Aebersold R, Martinez J, Jinek M. Molecular architecture of the human tRNA ligase complex. eLife 2021; 10:e71656. [PMID: 34854379 PMCID: PMC8668186 DOI: 10.7554/elife.71656] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/01/2021] [Indexed: 01/23/2023] Open
Abstract
RtcB enzymes are RNA ligases that play essential roles in tRNA splicing, unfolded protein response, and RNA repair. In metazoa, RtcB functions as part of a five-subunit tRNA ligase complex (tRNA-LC) along with Ddx1, Cgi-99, Fam98B, and Ashwin. The human tRNA-LC or its individual subunits have been implicated in additional cellular processes including microRNA maturation, viral replication, DNA double-strand break repair, and mRNA transport. Here, we present a biochemical analysis of the inter-subunit interactions within the human tRNA-LC along with crystal structures of the catalytic subunit RTCB and the N-terminal domain of CGI-99. We show that the core of the human tRNA-LC is assembled from RTCB and the C-terminal alpha-helical regions of DDX1, CGI-99, and FAM98B, all of which are required for complex integrity. The N-terminal domain of CGI-99 displays structural homology to calponin-homology domains, and CGI-99 and FAM98B associate via their N-terminal domains to form a stable subcomplex. The crystal structure of GMP-bound RTCB reveals divalent metal coordination geometry in the active site, providing insights into its catalytic mechanism. Collectively, these findings shed light on the molecular architecture and mechanism of the human tRNA ligase complex and provide a structural framework for understanding its functions in cellular RNA metabolism.
Collapse
Affiliation(s)
- Alena Kroupova
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Fabian Ackle
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Igor Asanović
- Max Perutz Labs, Vienna BioCenter (VBC)ViennaAustria
| | | | | | - Marco Faini
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | - Alessia Chui
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | | | - Martin Jinek
- Department of Biochemistry, University of ZurichZurichSwitzerland
| |
Collapse
|
18
|
Li Y, Wang WX. Integrated transcriptomics and proteomics revealed the distinct toxicological effects of multi-metal contamination on oysters. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117533. [PMID: 34261227 DOI: 10.1016/j.envpol.2021.117533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/24/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
The Pearl River Estuary (PRE) is the largest estuary in southern China and under high metal stress. In the present study, we employed an integrated method of transcriptomics and proteomics to investigate the ecotoxicological effects of trace metals on the Hong Kong oyster Crassostrea hongkongensis. Three oyster populations with distinct spatial distributions of metals were sampled, including the Control (Station QA, the lowest metal levels), the High Cd (Station JZ, the highest Cd), and the High Zn-Cu-Cr-Ni (Station LFS, with the highest levels of zinc, copper, chromium, and nickel). Dominant metals in oysters were differentiated by principal component analysis (PCA), and theirgene and protein profiles were studied using RNA-seq and iTRAQ techniques. Of the 2250 proteins identified at both protein and RNA levels, 70 proteins exhibited differential expressions in response to metal stress in oysters from the two contaminated stations. There were 8 proteins altered at both stations, with the potential effects on mitochondria and endoplasmic reticulum by Ag. The genotoxicity, including impaired DNA replication and transcription, was specifically observed in the High Cd oysters with the dominating influence of Cd. The structural components (cytoskeleton and chromosome-associated proteins) were impaired by the over-accumulated Cu, Zn, Cr, and Ni at Station LFS. However, enhanced tRNA biogenesis and exosome activity might help the oysters to alleviate the toxicities resulting from their exposure to these metals. Our study provided comprehensive information on the molecular changes in oysters at both protein and RNA levels in responding to multi-levels of trace metal stress.
Collapse
Affiliation(s)
- Yunlong Li
- Division of Life Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China; School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Wen-Xiong Wang
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China.
| |
Collapse
|
19
|
Kawamura T, Shigematsu M, Kirino Y. In vitro production and multiplex quantification of 2',3'-cyclic phosphate-containing 5'-tRNA half molecules. Methods 2021; 203:335-341. [PMID: 33962012 DOI: 10.1016/j.ymeth.2021.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/29/2022] Open
Abstract
RNA cleavages by many ribonucleases generate RNA molecules that contain a 2',3'-cyclic phosphate (cP) at their 3'-termini, and many cP-containing RNAs (cP-RNAs) are expressed as functional molecules in cells and tissues. 5'-tRNA half molecules are representative examples of functional cP-RNAs, playing important roles in various biological processes. We here show in vitro production of cP-containing 5'-tRNA half molecules that is able to prepare abundant synthetic cP-RNAs enough for functional analyses. Furthermore, we report a multiplex TaqMan RT-qPCR method which can simultaneously quantify multiple cP-containing 5'-tRNA half species. The method enabled us to efficiently quantify 5'-tRNA halves using samples with limited amounts, such as human plasma samples, revealing drastic enhancement of 5'-tRNA half levels at approximately 1,000-fold in patients infected with Mycobacterium tuberculosis. These in vitro production and multiplex quantification methods can be applied to any cP-RNAs, and they provide cost-effective, in-house techniques to accelerate expressional and functional characterizations of 5'-tRNA halves and other cP-RNAs.
Collapse
Affiliation(s)
- Takuya Kawamura
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Megumi Shigematsu
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Yohei Kirino
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
20
|
Jarrous N, Mani D, Ramanathan A. Coordination of transcription and processing of tRNA. FEBS J 2021; 289:3630-3641. [PMID: 33929081 DOI: 10.1111/febs.15904] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/02/2021] [Accepted: 04/28/2021] [Indexed: 12/17/2022]
Abstract
Coordination of transcription and processing of RNA is a basic principle in regulation of gene expression in eukaryotes. In the case of mRNA, coordination is primarily founded on a co-transcriptional processing mechanism by which a nascent precursor mRNA undergoes maturation via cleavage and modification by the transcription machinery. A similar mechanism controls the biosynthesis of rRNA. However, the coordination of transcription and processing of tRNA, a rather short transcript, remains unknown. Here, we present a model for high molecular weight initiation complexes of human RNA polymerase III that assemble on tRNA genes and process precursor transcripts to mature forms. These multifunctional initiation complexes may support co-transcriptional processing, such as the removal of the 5' leader of precursor tRNA by RNase P. Based on this model, maturation of tRNA is predetermined prior to transcription initiation.
Collapse
Affiliation(s)
- Nayef Jarrous
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dhivakar Mani
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Aravind Ramanathan
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| |
Collapse
|
21
|
RNA-Targeting Splicing Modifiers: Drug Development and Screening Assays. Molecules 2021; 26:molecules26082263. [PMID: 33919699 PMCID: PMC8070285 DOI: 10.3390/molecules26082263] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 02/06/2023] Open
Abstract
RNA splicing is an essential step in producing mature messenger RNA (mRNA) and other RNA species. Harnessing RNA splicing modifiers as a new pharmacological modality is promising for the treatment of diseases caused by aberrant splicing. This drug modality can be used for infectious diseases by disrupting the splicing of essential pathogenic genes. Several antisense oligonucleotide splicing modifiers were approved by the U.S. Food and Drug Administration (FDA) for the treatment of spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD). Recently, a small-molecule splicing modifier, risdiplam, was also approved for the treatment of SMA, highlighting small molecules as important warheads in the arsenal for regulating RNA splicing. The cellular targets of these approved drugs are all mRNA precursors (pre-mRNAs) in human cells. The development of novel RNA-targeting splicing modifiers can not only expand the scope of drug targets to include many previously considered “undruggable” genes but also enrich the chemical-genetic toolbox for basic biomedical research. In this review, we summarized known splicing modifiers, screening methods for novel splicing modifiers, and the chemical space occupied by the small-molecule splicing modifiers.
Collapse
|
22
|
Deng Y, Wu X, Wen D, Huang H, Chen Y, Mukhtar I, Yue L, Wang L, Wen Z. Intraspecific Mitochondrial DNA Comparison of Mycopathogen Mycogone perniciosa Provides Insight Into Mitochondrial Transfer RNA Introns. PHYTOPATHOLOGY 2021; 111:639-648. [PMID: 32886023 DOI: 10.1094/phyto-07-20-0281-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Mycogone perniciosa is the main causative agent of wet bubble disease, which causes severe damage to the production of the cultivated mushroom Agaricus bisporus around the world. Whole-genome sequencing of 12 isolates of M. perniciosa was performed using the Illumina sequencing platform, and the obtained paired-end reads were used to assemble complete mitochondrial genomes. Intraspecific comparisons of conserved protein-coding genes, transfer RNA (tRNA) and ribosomal RNA (rRNA) genes, introns, and intergenic regions were conducted. Five different mitochondrial DNA (mtDNA) haplotypes were detected among the tested isolates, ranging from 89,080 to 93,199 bp in length. All of the mtDNAs contained the same set of 14 protein-coding genes and 2 rRNA and 27 tRNA genes, which shared high sequence similarity. In contrast, the number, insertion sites, and sequences of introns varied greatly among the mtDNAs. Eighteen of 43 intergenic regions differed among the isolates, reflecting 65 single nucleotide polymorphisms, 76 indels, and the gain/loss of nine long fragments. Intraspecific comparison revealed that two introns were located within tRNA genes, which is the first detailed description of mitochondrial tRNA introns. Intronic sequence comparison within the same insertion sites revealed the formation process of two introns, which also illustrated a fast evolutionary rate of introns among M. perniciosa isolates. Based on the intron distribution pattern, a pair of universal primers and four pairs of isolate-specific primers were designed and were used to identify the five mtDNA types. In summary, the rapid gain or loss of mitochondrial introns could be an ideal marker for population genetics analysis.
Collapse
Affiliation(s)
- Youjin Deng
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xin Wu
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Die Wen
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Haichen Huang
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yilei Chen
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Irum Mukhtar
- Institute of Oceanography, Minjiang University, Fuzhou 350108, China
| | - Liyun Yue
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Li Wang
- Shandong Key Laboratory of Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271000, China
| | - Zhiqiang Wen
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| |
Collapse
|
23
|
Dantuluri S, Schwer B, Abdullahu L, Damha MJ, Shuman S. Activity and substrate specificity of Candida, Aspergillus, and Coccidioides Tpt1: essential tRNA splicing enzymes and potential anti-fungal targets. RNA (NEW YORK, N.Y.) 2021; 27:rna.078660.120. [PMID: 33509912 PMCID: PMC8051265 DOI: 10.1261/rna.078660.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
The enzyme Tpt1 is an essential agent of fungal tRNA splicing that removes an internal RNA 2'-PO4 generated by fungal tRNA ligase. Tpt1 performs a two-step reaction in which: (i) the 2'-PO4 attacks NAD+ to form an RNA-2'-phospho-(ADP-ribose) intermediate; and (ii) transesterification of the ADP-ribose O2'' to the RNA 2'-phosphodiester yields 2'-OH RNA and ADP-ribose-1'',2''-cyclic phosphate. Because Tpt1 does not participate in metazoan tRNA splicing, and Tpt1 knockout has no apparent impact on mammalian physiology, Tpt1 is considered a potential anti-fungal drug target. Here we characterize Tpt1 enzymes from four human fungal pathogens: Coccidioides immitis, the agent of Valley Fever; Aspergillus fumigatus and Candida albicans, which cause invasive, often fatal, infections in immunocompromised hosts; and Candida auris, an emerging pathogen that is resistant to current therapies. All four pathogen Tpt1s were active in vivo in complementing a lethal Saccharomyces cerevisiae tpt1∆ mutation and in vitro in NAD+-dependent conversion of a 2'-PO4 to a 2'-OH. The fungal Tpt1s utilized nicotinamide hypoxanthine dinucleotide as a substrate in lieu of NAD+, albeit with much lower affinity, whereas nicotinic acid adenine dinucleotide was ineffective. Fungal Tpt1s efficiently removed an internal ribonucleotide 2'-phosphate from an otherwise all-DNA substrate. Replacement of an RNA ribose-2'-PO4 nucleotide with arabinose-2'-PO4 diminished enzyme specific activity by ≥2000-fold and selectively slowed step 2 of the reaction pathway, resulting in transient accumulation of an ara-2'-phospho-ADP-ribosylated intermediate. Our results implicate the 2'-PO4 ribonucleotide as the principal determinant of fungal Tpt1 nucleic acid substrate specificity.
Collapse
|
24
|
Berk C, Wang Y, Laski A, Tsagkris S, Hall J. Ligation of 2', 3'-cyclic phosphate RNAs for the identification of microRNA binding sites. FEBS Lett 2020; 595:230-240. [PMID: 33113149 PMCID: PMC7894349 DOI: 10.1002/1873-3468.13976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/27/2020] [Accepted: 10/08/2020] [Indexed: 11/21/2022]
Abstract
Identifying the targetome of a microRNA is key for understanding its functions. Cross‐linking and immunoprecipitation (CLIP) methods capture native miRNA‐mRNA interactions in cells. Some of these methods yield small amounts of chimeric miRNA‐mRNA sequences via ligation of 5′‐phosphorylated RNAs produced during the protocol. Here, we introduce chemically synthesized microRNAs (miRNAs) bearing 2′‐, 3′‐cyclic phosphate groups, as part of a new CLIP method that does not require 5′‐phosphorylation for ligation. We show in a system that models miRNAs bound to their targets, that addition of recombinant bacterial ligase RtcB increases ligation efficiency, and that the transformation proceeds via a 3′‐phosphate intermediate. By optimizing the chemistry underlying ligation, we provide the basis for an improved method to identify miRNA targetomes.
Collapse
Affiliation(s)
- Christian Berk
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Yuluan Wang
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Artur Laski
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Stylianos Tsagkris
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Jonathan Hall
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| |
Collapse
|
25
|
Gunathilake KMD, Halmillawewa AP, MacKenzie KD, Perry BJ, Yost CK, Hynes MF. A bacteriophage infecting Mesorhizobium species has a prolate capsid and shows similarities to a family of Caulobacter crescentus phages. Can J Microbiol 2020; 67:147-160. [PMID: 32905709 DOI: 10.1139/cjm-2020-0281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mesorhizobium phage vB_MloS_Cp1R7A-A1 was isolated from soil planted with chickpea in Saskatchewan. It is dissimilar in sequence and morphology to previously described rhizobiophages. It is a B3 morphotype virus with a distinct prolate capsid and belongs to the tailed phage family Siphoviridae. Its genome has a GC content of 60.3% and 238 predicted genes. Putative functions were predicted for 57 genes, which include 27 tRNA genes with anticodons corresponding to 18 amino acids. This represents the highest number of tRNA genes reported yet in a rhizobiophage. The gene arrangement shows a partially modular organization. Most of the structural genes are found in one module, whereas tRNA genes are in another. Genes for replication, recombination, and nucleotide metabolism form the third module. The arrangement of the replication module resembles the replication module of Enterobacteria phage T5, raising the possibility that it uses a recombination-based replication mechanism, but there is also a suggestion that a T7-like replication mechanism could be used. Phage termini appear to be long direct repeats of just over 12 kb in length. Phylogenetic analysis revealed that Cp1R7A-A1 is more closely related to PhiCbK-like Caulobacter phages and other B3 morphotype phages than to other rhizobiophages sequenced thus far.
Collapse
Affiliation(s)
| | - Anupama P Halmillawewa
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.,Department of Microbiology, University of Kelaniya, Sri Lanka
| | - Keith D MacKenzie
- Biology Department, University of Regina, Regina Saskatchewan, Canada
| | - Benjamin J Perry
- Biology Department, University of Regina, Regina Saskatchewan, Canada.,Department of Microbiology, University of Otago, Dunedin, New Zealand
| | | | - Michael F Hynes
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
26
|
Dantuluri S, Abdullahu L, Munir A, Katolik A, Damha MJ, Shuman S. Substrate analogs that trap the 2'-phospho-ADP-ribosylated RNA intermediate of the Tpt1 (tRNA 2'-phosphotransferase) reaction pathway. RNA (NEW YORK, N.Y.) 2020; 26:373-381. [PMID: 31932322 PMCID: PMC7075268 DOI: 10.1261/rna.074377.119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 01/10/2020] [Indexed: 05/06/2023]
Abstract
The enzyme Tpt1 removes an internal RNA 2'-PO4 via a two-step reaction in which: (i) the 2'-PO4 attacks NAD+ to form an RNA-2'-phospho-(ADP-ribose) intermediate and nicotinamide; and (ii) transesterification of the ADP-ribose O2″ to the RNA 2'-phosphodiester yields 2'-OH RNA and ADP-ribose-1″,2″-cyclic phosphate. Because step 2 is much faster than step 1, the ADP-ribosylated RNA intermediate is virtually undetectable under normal circumstances. Here, by testing chemically modified nucleic acid substrates for activity with bacterial Tpt1 enzymes, we find that replacement of the ribose-2'-PO4 nucleotide with arabinose-2'-PO4 selectively slows step 2 of the reaction pathway and results in the transient accumulation of high levels of the reaction intermediate. We report that replacing the NMN ribose of NAD+ with 2'-fluoroarabinose (thereby eliminating the ribose O2″ nucleophile) results in durable trapping of RNA-2'-phospho-(ADP-fluoroarabinose) as a "dead-end" product of step 1. Tpt1 enzymes from diverse taxa differ in their capacity to use ara-2″F-NAD+ as a substrate.
Collapse
Affiliation(s)
- Swathi Dantuluri
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Leonora Abdullahu
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - Annum Munir
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Adam Katolik
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, Quebec H3A0B8, Canada
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| |
Collapse
|
27
|
Abstract
ADP-ribosylation is an intricate and versatile posttranslational modification involved in the regulation of a vast variety of cellular processes in all kingdoms of life. Its complexity derives from the varied range of different chemical linkages, including to several amino acid side chains as well as nucleic acids termini and bases, it can adopt. In this review, we provide an overview of the different families of (ADP-ribosyl)hydrolases. We discuss their molecular functions, physiological roles, and influence on human health and disease. Together, the accumulated data support the increasingly compelling view that (ADP-ribosyl)hydrolases are a vital element within ADP-ribosyl signaling pathways and they hold the potential for novel therapeutic approaches as well as a deeper understanding of ADP-ribosylation as a whole.
Collapse
Affiliation(s)
| | - Luca Palazzo
- Institute for the Experimental Endocrinology and Oncology, National Research Council of Italy, 80145 Naples, Italy
| | - Ivan Ahel
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| |
Collapse
|
28
|
Schmidt CA, Giusto JD, Bao A, Hopper AK, Matera AG. Molecular determinants of metazoan tricRNA biogenesis. Nucleic Acids Res 2020; 47:6452-6465. [PMID: 31032518 PMCID: PMC6614914 DOI: 10.1093/nar/gkz311] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/12/2019] [Accepted: 04/18/2019] [Indexed: 12/22/2022] Open
Abstract
Mature tRNAs are generated by multiple post-transcriptional processing steps, which can include intron removal. Recently, we discovered a new class of circular non-coding RNAs in metazoans, called tRNA intronic circular (tric)RNAs. To investigate the mechanism of tricRNA biogenesis, we generated constructs that replace native introns of human and fruit fly tRNA genes with the Broccoli fluorescent RNA aptamer. Using these reporters, we identified cis-acting elements required for tricRNA formation in vivo. Disrupting a conserved base pair in the anticodon-intron helix dramatically reduces tricRNA levels. Although the integrity of this base pair is necessary for proper splicing, it is not sufficient. In contrast, strengthening weak bases in the helix also interferes with splicing and tricRNA production. Furthermore, we identified trans-acting factors important for tricRNA biogenesis, including several known tRNA processing enzymes such as the RtcB ligase and components of the TSEN endonuclease complex. Depletion of these factors inhibits Drosophila tRNA intron circularization. Notably, RtcB is missing from fungal genomes and these organisms normally produce linear tRNA introns. Here, we show that in the presence of ectopic RtcB, yeast lacking the tRNA ligase Rlg1/Trl1 are converted into producing tricRNAs. In summary, our work characterizes the major players in eukaryotic tricRNA biogenesis.
Collapse
Affiliation(s)
- Casey A Schmidt
- Curriculum in Genetics & Molecular Biology and Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Joseph D Giusto
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Alicia Bao
- Center for RNA Biology and Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
| | - Anita K Hopper
- Center for RNA Biology and Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
| | - A Gregory Matera
- Curriculum in Genetics & Molecular Biology and Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA.,Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.,Department of Genetics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| |
Collapse
|
29
|
Schmidt CA, Matera AG. tRNA introns: Presence, processing, and purpose. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1583. [DOI: 10.1002/wrna.1583] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Casey A. Schmidt
- Curriculum in Genetics and Molecular Biology Integrative Program for Biological and Genome Sciences, University of North Carolina Chapel Hill North Carolina
| | - A. Gregory Matera
- Curriculum in Genetics and Molecular Biology Integrative Program for Biological and Genome Sciences, University of North Carolina Chapel Hill North Carolina
- Department of Biology, Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina
- Department of Genetics, Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina
| |
Collapse
|
30
|
Muslin C, Mac Kain A, Bessaud M, Blondel B, Delpeyroux F. Recombination in Enteroviruses, a Multi-Step Modular Evolutionary Process. Viruses 2019; 11:E859. [PMID: 31540135 PMCID: PMC6784155 DOI: 10.3390/v11090859] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 01/15/2023] Open
Abstract
RNA recombination is a major driving force in the evolution and genetic architecture shaping of enteroviruses. In particular, intertypic recombination is implicated in the emergence of most pathogenic circulating vaccine-derived polioviruses, which have caused numerous outbreaks of paralytic poliomyelitis worldwide. Recent experimental studies that relied on recombination cellular systems mimicking natural genetic exchanges between enteroviruses provided new insights into the molecular mechanisms of enterovirus recombination and enabled to define a new model of genetic plasticity for enteroviruses. Homologous intertypic recombinant enteroviruses that were observed in nature would be the final products of a multi-step process, during which precursor nonhomologous recombinant genomes are generated through an initial inter-genomic RNA recombination event and can then evolve into a diversity of fitter homologous recombinant genomes over subsequent intra-genomic rearrangements. Moreover, these experimental studies demonstrated that the enterovirus genome could be defined as a combination of genomic modules that can be preferentially exchanged through recombination, and enabled defining the boundaries of these recombination modules. These results provided the first experimental evidence supporting the theoretical model of enterovirus modular evolution previously elaborated from phylogenetic studies of circulating enterovirus strains. This review summarizes our current knowledge regarding the mechanisms of recombination in enteroviruses and presents a new evolutionary process that may apply to other RNA viruses.
Collapse
Affiliation(s)
- Claire Muslin
- One Health Research Group, Faculty of Health Sciences, Universidad de las Américas, Quito EC170125, Pichincha, Ecuador.
| | - Alice Mac Kain
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Maël Bessaud
- Institut Pasteur, Viral Populations and Pathogenesis Unit, CNRS UMR 3569, 75015 Paris, France.
| | - Bruno Blondel
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
| | - Francis Delpeyroux
- Institut Pasteur, Biology of Enteric Viruses Unit, 75015 Paris, France.
- INSERM U994, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France.
| |
Collapse
|
31
|
Kirsch R, Olzog VJ, Bonin S, Weinberg CE, Betat H, Stadler PF, Mörl M. A streamlined protocol for the detection of mRNA-sRNA interactions using AMT-crosslinking in vitro. Biotechniques 2019; 67:178-183. [PMID: 31462065 DOI: 10.2144/btn-2019-0047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Until recently, RNA-RNA interactions were mainly identified by crosslinking RNAs with interacting proteins, RNA proximity ligation and deep sequencing. Recently, AMT-based direct RNA crosslinking was established. Yet, several steps of these procedures are rather inefficient, reducing the output of identified interaction partners. To increase the local concentration of RNA ends, interacting RNAs are often fragmented. However, the resulting 2',3'-cyclic phosphate and 5'-OH ends are not accepted by T4 RNA ligase and have to be converted to 3'-OH and 5'-phosphate ends. Using an artificial mRNA/sRNA pair, we optimized the workflow downstream of the crosslinking reaction in vitro. The use of a tRNA ligase allows direct fusion of 2',3'-cyclic phosphate and 5'-OH RNA ends.
Collapse
Affiliation(s)
- Rebecca Kirsch
- Institute for Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany.,Center for Non-Coding RNA in Technology & Health, Grønnegårdsvej 3, 1870 Frederiksberg C, Denmark
| | - V Janett Olzog
- Institute for Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| | - Sonja Bonin
- Institute for Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| | | | - Heike Betat
- Institute for Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| | - Peter F Stadler
- Center for Non-Coding RNA in Technology & Health, Grønnegårdsvej 3, 1870 Frederiksberg C, Denmark.,Bioinformatics Group, Department of Computer Science & Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, 04103 Leipzig, Germany.,Department of Theoretical Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.,Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
| | - Mario Mörl
- Institute for Biochemistry, Brüderstraße 34, 04103 Leipzig, Germany
| |
Collapse
|
32
|
Munir A, Abdullahu L, Banerjee A, Damha MJ, Shuman S. NAD +-dependent RNA terminal 2' and 3' phosphomonoesterase activity of a subset of Tpt1 enzymes. RNA (NEW YORK, N.Y.) 2019; 25:783-792. [PMID: 31019096 PMCID: PMC6573784 DOI: 10.1261/rna.071142.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/04/2019] [Indexed: 05/06/2023]
Abstract
The enzyme Tpt1 removes the 2'-PO4 at the splice junction generated by fungal tRNA ligase; it does so via a two-step reaction in which (i) the internal RNA 2'-PO4 attacks NAD+ to form an RNA-2'-phospho-ADP-ribosyl intermediate; and (ii) transesterification of the ribose O2″ to the 2'-phosphodiester yields 2'-OH RNA and ADP-ribose-1″,2″-cyclic phosphate products. The role that Tpt1 enzymes play in taxa that have no fungal-type RNA ligase remains obscure. An attractive prospect is that Tpt1 enzymes might catalyze reactions other than internal RNA 2'-PO4 removal, via their unique NAD+-dependent transferase mechanism. This study extends the repertoire of the Tpt1 enzyme family to include the NAD+-dependent conversion of RNA terminal 2' and 3' monophosphate ends to 2'-OH and 3'-OH ends, respectively. The salient finding is that different Tpt1 enzymes vary in their capacity and positional specificity for terminal phosphate removal. Clostridium thermocellum and Aeropyrum pernix Tpt1 proteins are active on 2'-PO4 and 3'-PO4 ends, with a 2.4- to 2.6-fold kinetic preference for the 2'-PO4 The accumulation of a terminal 3'-phospho-ADP-ribosylated RNA intermediate during the 3'-phosphotransferase reaction suggests that the geometry of the 3'-p-ADPR adduct is not optimal for the ensuing transesterification step. Chaetomium thermophilum Tpt1 acts specifically on a terminal 2'-PO4 end and not with a 3'-PO4 In contrast, Runella slithyformis Tpt1 and human Tpt1 are ineffective in removing either a 2'-PO4 or 3'-PO4 end.
Collapse
Affiliation(s)
- Annum Munir
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Leonora Abdullahu
- Department of Chemistry, McGill University, Montreal, Quebec, Canada H3A0B8
| | - Ankan Banerjee
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, Quebec, Canada H3A0B8
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| |
Collapse
|
33
|
Peschek J, Walter P. tRNA ligase structure reveals kinetic competition between non-conventional mRNA splicing and mRNA decay. eLife 2019; 8:44199. [PMID: 31237564 PMCID: PMC6592678 DOI: 10.7554/elife.44199] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 06/11/2019] [Indexed: 01/11/2023] Open
Abstract
Yeast tRNA ligase (Trl1) is an essential trifunctional enzyme that catalyzes exon-exon ligation during tRNA biogenesis and the non-conventional splicing of HAC1 mRNA during the unfolded protein response (UPR). The UPR regulates the protein folding capacity of the endoplasmic reticulum (ER). ER stress activates Ire1, an ER-resident kinase/RNase, which excises an intron from HAC1 mRNA followed by exon-exon ligation by Trl1. The spliced product encodes for a potent transcription factor that drives the UPR. Here we report the crystal structure of Trl1 RNA ligase domain from Chaetomium thermophilum at 1.9 Å resolution. Structure-based mutational analyses uncovered kinetic competition between RNA ligation and degradation during HAC1 mRNA splicing. Incompletely processed HAC1 mRNA is degraded by Xrn1 and the Ski/exosome complex. We establish cleaved HAC1 mRNA as endogenous substrate for ribosome-associated quality control. We conclude that mRNA decay and surveillance mechanisms collaborate in achieving fidelity of non-conventional mRNA splicing during the UPR.
Collapse
Affiliation(s)
- Jirka Peschek
- Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Peter Walter
- Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| |
Collapse
|
34
|
Hopper AK, Nostramo RT. tRNA Processing and Subcellular Trafficking Proteins Multitask in Pathways for Other RNAs. Front Genet 2019; 10:96. [PMID: 30842788 PMCID: PMC6391926 DOI: 10.3389/fgene.2019.00096] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/29/2019] [Indexed: 01/28/2023] Open
Abstract
This article focuses upon gene products that are involved in tRNA biology, with particular emphasis upon post-transcriptional RNA processing and nuclear-cytoplasmic subcellular trafficking. Rather than analyzing these proteins solely from a tRNA perspective, we explore the many overlapping functions of the processing enzymes and proteins involved in subcellular traffic. Remarkably, there are numerous examples of conserved gene products and RNP complexes involved in tRNA biology that multitask in a similar fashion in the production and/or subcellular trafficking of other RNAs, including small structured RNAs such as snRNA, snoRNA, 5S RNA, telomerase RNA, and SRP RNA as well as larger unstructured RNAs such as mRNAs and RNA-protein complexes such as ribosomes. Here, we provide examples of steps in tRNA biology that are shared with other RNAs including those catalyzed by enzymes functioning in 5' end-processing, pseudoU nucleoside modification, and intron splicing as well as steps regulated by proteins functioning in subcellular trafficking. Such multitasking highlights the clever mechanisms cells employ for maximizing their genomes.
Collapse
Affiliation(s)
- Anita K Hopper
- Department of Molecular Genetics, Center for RNA Biology, Ohio State University, Columbus, OH, United States
| | - Regina T Nostramo
- Department of Molecular Genetics, Center for RNA Biology, Ohio State University, Columbus, OH, United States
| |
Collapse
|
35
|
Banerjee A, Munir A, Abdullahu L, Damha MJ, Goldgur Y, Shuman S. Structure of tRNA splicing enzyme Tpt1 illuminates the mechanism of RNA 2'-PO 4 recognition and ADP-ribosylation. Nat Commun 2019; 10:218. [PMID: 30644400 PMCID: PMC6333775 DOI: 10.1038/s41467-018-08211-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/20/2018] [Indexed: 11/30/2022] Open
Abstract
Tpt1 is an essential agent of fungal tRNA splicing that removes the 2′-PO4 at the splice junction generated by fungal tRNA ligase. Tpt1 catalyzes a unique two-step reaction whereby the 2′-PO4 attacks NAD+ to form an RNA-2′-phospho-ADP-ribosyl intermediate that undergoes transesterification to yield 2′-OH RNA and ADP-ribose-1″,2″-cyclic phosphate products. Because Tpt1 is inessential in exemplary bacterial and mammalian taxa, Tpt1 is seen as an attractive antifungal target. Here we report a 1.4 Å crystal structure of Tpt1 in a product-mimetic complex with ADP-ribose-1″-phosphate in the NAD+ site and pAp in the RNA site. The structure reveals how Tpt1 recognizes a 2′-PO4 RNA splice junction and the mechanism of RNA phospho-ADP-ribosylation. This study also provides evidence that a bacterium has an endogenous phosphorylated substrate with which Tpt1 reacts. Tpt1 catalyzes the final essential step in yeast tRNA splicing and is a potential antifungal target. Here the authors provide structural insights into how Tpt1 recognizes a 2’-PO4 RNA splice junction and the mechanism of RNA phospho-ADP-ribosylation.
Collapse
Affiliation(s)
- Ankan Banerjee
- Molecular Biology and Structural Biology Programs, Sloan-Kettering Institute, New York, NY, 10065, USA
| | - Annum Munir
- Molecular Biology and Structural Biology Programs, Sloan-Kettering Institute, New York, NY, 10065, USA
| | - Leonora Abdullahu
- Chemistry Department, McGill University, Montreal, Quebec, H3A0B8, Canada
| | - Masad J Damha
- Chemistry Department, McGill University, Montreal, Quebec, H3A0B8, Canada
| | - Yehuda Goldgur
- Molecular Biology and Structural Biology Programs, Sloan-Kettering Institute, New York, NY, 10065, USA
| | - Stewart Shuman
- Molecular Biology and Structural Biology Programs, Sloan-Kettering Institute, New York, NY, 10065, USA.
| |
Collapse
|
36
|
Unlu I, Lu Y, Wang X. The cyclic phosphodiesterase CNP and RNA cyclase RtcA fine-tune noncanonical XBP1 splicing during ER stress. J Biol Chem 2018; 293:19365-19376. [PMID: 30355738 PMCID: PMC6302167 DOI: 10.1074/jbc.ra118.004872] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/12/2018] [Indexed: 12/21/2022] Open
Abstract
The activity of X box-binding protein 1 (XBP1), a master transcriptional regulator of endoplasmic reticulum (ER) homeostasis and the unfolded protein response (UPR), is controlled by a two-step noncanonical splicing reaction in the cytoplasm. The first step of nuclease cleavage by inositol-requiring enzyme 1 (IRE1), a protein kinase/endoribonuclease, is conserved in all eukaryotic cells. The second step of RNA ligation differs biochemically among species. In yeast, tRNA ligase 1 (Trl1) and tRNA 2'-phosphotransferase 1 (Tpt1) act through a 5'-PO4/3'-OH pathway. In metazoans, RNA 2',3'-cyclic phosphate and 5'-OH ligase (RtcB) ligate XBP1 exons via a 3'-PO4/5'-OH reaction. Although RtcB has been identified as the primary RNA ligase, evidence suggests that yeast-like ligase components may also operate in mammals. In this study, using mouse and human cell lines along with in vitro splicing assays, we investigated whether these components contribute to XBP1 splicing during ER stress. We found that the mammalian 2'-phosphotransferase Trpt1 does not contribute to XBP1 splicing even in the absence of RtcB. Instead, we found that 2',3'-cyclic nucleotide phosphodiesterase (CNP) suppresses RtcB-mediated XBP1 splicing by hydrolyzing 2',3'-cyclic phosphate into 2'-phosphate on the cleaved exon termini. By contrast, RNA 3'-terminal cyclase (RtcA), which converts 2'-phosphate back to 2',3'-cyclic phosphate, facilitated XBP1 splicing by increasing the number of compatible RNA termini for RtcB. Taken together, our results provide evidence that CNP and RtcA fine-tune XBP1 output during ER stress.
Collapse
Affiliation(s)
- Irem Unlu
- From the Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| | - Yanyan Lu
- From the Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| | - Xiaozhong Wang
- From the Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| |
Collapse
|
37
|
Shigematsu M, Kawamura T, Kirino Y. Generation of 2',3'-Cyclic Phosphate-Containing RNAs as a Hidden Layer of the Transcriptome. Front Genet 2018; 9:562. [PMID: 30538719 PMCID: PMC6277466 DOI: 10.3389/fgene.2018.00562] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/06/2018] [Indexed: 01/03/2023] Open
Abstract
Cellular RNA molecules contain phosphate or hydroxyl ends. A 2′,3′-cyclic phosphate (cP) is one of the 3′-terminal forms of RNAs mainly generated from RNA cleavage by ribonucleases. Although transcriptome profiling using RNA-seq has become a ubiquitous tool in biological and medical research, cP-containing RNAs (cP-RNAs) form a hidden transcriptome layer, which is infrequently recognized and characterized, because standard RNA-seq is unable to capture them. Despite cP-RNAs’ invisibility in RNA-seq data, increasing evidence indicates that they are not accumulated simply as non-functional degradation products; rather, they have physiological roles in various biological processes, designating them as noteworthy functional molecules. This review summarizes our current knowledge of cP-RNA biogenesis pathways and their catalytic enzymatic activities, discusses how the cP-RNA generation affects biological processes, and explores future directions to further investigate cP-RNA biology.
Collapse
Affiliation(s)
- Megumi Shigematsu
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Takuya Kawamura
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Yohei Kirino
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| |
Collapse
|
38
|
Munir A, Abdullahu L, Damha MJ, Shuman S. Two-step mechanism and step-arrest mutants of Runella slithyformis NAD +-dependent tRNA 2'-phosphotransferase Tpt1. RNA (NEW YORK, N.Y.) 2018; 24:1144-1157. [PMID: 29884622 PMCID: PMC6097658 DOI: 10.1261/rna.067165.118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/23/2018] [Indexed: 05/06/2023]
Abstract
Tpt1 catalyzes the transfer of an internal 2'-monophosphate moiety (2'-PO4) from a "branched" 2'-PO4 RNA splice junction to NAD+ to form a "clean" 2'-OH, 3'-5' phosphodiester junction, ADP-ribose 1″-2″ cyclic phosphate, and nicotinamide. First discovered as an essential component of the Saccharomyces cerevisiae tRNA splicing machinery, Tpt1 is widely distributed in nature, including in taxa that have no yeast-like RNA splicing system. Here we characterize the RslTpt1 protein from the bacterium Runella slithyformis, in which Tpt1 is encoded within a putative RNA repair gene cluster. We find that (i) expression of RslTpt1 in yeast complements a lethal tpt1Δ knockout, and (ii) purified recombinant RslTpt1 is a bona fide NAD+-dependent 2'-phosphotransferase capable of completely removing an internal 2'-phosphate from synthetic RNAs. The in vivo activity of RslTpt1 is abolished by alanine substitutions for conserved amino acids Arg16, His17, Arg64, and Arg119. The R64A, R119A, and H17A mutants accumulate high levels of a 2'-phospho-ADP-ribosylated RNA reaction intermediate (2'-P-ADPR, evanescent in the wild-type RslTpt1 reaction), which is converted slowly to a 2'-OH RNA product. The R16A mutant is 300-fold slower than wild-type RslTpt1 in forming the 2'-P-ADPR intermediate. Whereas wild-type RsTpt1 rapidly converts the isolated 2'-P-ADPR intermediate to 2'-OH product in the absence of NAD+, the H17A, R119A, R64A, and R16A mutant are slower by factors of 3, 33, 210, and 710, respectively. Our results identify active site constituents involved in the catalysis of step 1 and step 2 of the Tpt1 reaction pathway.
Collapse
Affiliation(s)
- Annum Munir
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Leonora Abdullahu
- Chemistry Department, McGill University, Montreal, Quebec H3A2A7, Canada
| | - Masad J Damha
- Chemistry Department, McGill University, Montreal, Quebec H3A2A7, Canada
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| |
Collapse
|
39
|
Chatterjee K, Nostramo RT, Wan Y, Hopper AK. tRNA dynamics between the nucleus, cytoplasm and mitochondrial surface: Location, location, location. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:373-386. [PMID: 29191733 PMCID: PMC5882565 DOI: 10.1016/j.bbagrm.2017.11.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 01/20/2023]
Abstract
Although tRNAs participate in the essential function of protein translation in the cytoplasm, tRNA transcription and numerous processing steps occur in the nucleus. This subcellular separation between tRNA biogenesis and function requires that tRNAs be efficiently delivered to the cytoplasm in a step termed "primary tRNA nuclear export". Surprisingly, tRNA nuclear-cytoplasmic traffic is not unidirectional, but, rather, movement is bidirectional. Cytoplasmic tRNAs are imported back to the nucleus by the "tRNA retrograde nuclear import" step which is conserved from budding yeast to vertebrate cells and has been hijacked by viruses, such as HIV, for nuclear import of the viral reverse transcription complex in human cells. Under appropriate environmental conditions cytoplasmic tRNAs that have been imported into the nucleus return to the cytoplasm via the 3rd nuclear-cytoplasmic shuttling step termed "tRNA nuclear re-export", that again is conserved from budding yeast to vertebrate cells. We describe the 3 steps of tRNA nuclear-cytoplasmic movements and their regulation. There are multiple tRNA nuclear export and import pathways. The different tRNA nuclear exporters appear to possess substrate specificity leading to the tantalizing possibility that the cellular proteome may be regulated at the level of tRNA nuclear export. Moreover, in some organisms, such as budding yeast, the pre-tRNA splicing heterotetrameric endonuclease (SEN), which removes introns from pre-tRNAs, resides on the cytoplasmic surface of the mitochondria. Therefore, we also describe the localization of the SEN complex to mitochondria and splicing of pre-tRNA on mitochondria, which occurs prior to the participation of tRNAs in protein translation. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
Collapse
Affiliation(s)
- Kunal Chatterjee
- The Ohio State University Comprehensive Cancer Research Center, United States; Department of Molecular Genetics, The Ohio State University, United States; Center for RNA Biology, The Ohio State University, United States
| | - Regina T Nostramo
- Department of Molecular Genetics, The Ohio State University, United States; Center for RNA Biology, The Ohio State University, United States
| | - Yao Wan
- The Ohio State University Comprehensive Cancer Research Center, United States; Department of Molecular Genetics, The Ohio State University, United States; Center for RNA Biology, The Ohio State University, United States
| | - Anita K Hopper
- Department of Molecular Genetics, The Ohio State University, United States; Center for RNA Biology, The Ohio State University, United States.
| |
Collapse
|
40
|
Kaneta A, Fujishima K, Morikazu W, Hori H, Hirata A. The RNA-splicing endonuclease from the euryarchaeaon Methanopyrus kandleri is a heterotetramer with constrained substrate specificity. Nucleic Acids Res 2018; 46:1958-1972. [PMID: 29346615 PMCID: PMC5829648 DOI: 10.1093/nar/gky003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/25/2017] [Accepted: 01/03/2018] [Indexed: 11/14/2022] Open
Abstract
Four different types (α4, α'2, (αβ)2 and ϵ2) of RNA-splicing endonucleases (EndAs) for RNA processing are known to exist in the Archaea. Only the (αβ)2 and ϵ2 types can cleave non-canonical introns in precursor (pre)-tRNA. Both enzyme types possess an insert associated with a specific loop, allowing broad substrate specificity in the catalytic α units. Here, the hyperthermophilic euryarchaeon Methanopyrus kandleri (MKA) was predicted to harbor an (αβ)2-type EndA lacking the specific loop. To characterize MKA EndA enzymatic activity, we constructed a fusion protein derived from MKA α and β subunits (fMKA EndA). In vitro assessment demonstrated complete removal of the canonical bulge-helix-bulge (BHB) intron structure from MKA pre-tRNAAsn. However, removal of the relaxed BHB structure in MKA pre-tRNAGlu was inefficient compared to crenarchaeal (αβ)2 EndA, and the ability to process the relaxed intron within mini-helix RNA was not detected. fMKA EndA X-ray structure revealed a shape similar to that of other EndA types, with no specific loop. Mapping of EndA types and their specific loops and the tRNA gene diversity among various Archaea suggest that MKA EndA is evolutionarily related to other (αβ)2-type EndAs found in the Thaumarchaeota, Crenarchaeota and Aigarchaeota but uniquely represents constrained substrate specificity.
Collapse
Affiliation(s)
- Ayano Kaneta
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Kosuke Fujishima
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
| | - Wataru Morikazu
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Akira Hirata
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| |
Collapse
|
41
|
Faktorová D, Valach M, Kaur B, Burger G, Lukeš J. Mitochondrial RNA Editing and Processing in Diplonemid Protists. RNA METABOLISM IN MITOCHONDRIA 2018. [DOI: 10.1007/978-3-319-78190-7_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
|
42
|
Processing of Potato Spindle Tuber Viroid RNAs in Yeast, a Nonconventional Host. J Virol 2017; 91:JVI.01078-17. [PMID: 28978701 DOI: 10.1128/jvi.01078-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/23/2017] [Indexed: 11/20/2022] Open
Abstract
Potato spindle tuber viroid (PSTVd) is a circular, single-stranded, noncoding RNA plant pathogen that is a useful model for studying the processing of noncoding RNA in eukaryotes. Infective PSTVd circles are replicated via an asymmetric rolling circle mechanism to form linear multimeric RNAs. An endonuclease cleaves these into monomers, and a ligase seals these into mature circles. All eukaryotes may have such enzymes for processing noncoding RNA. As a test, we investigated the processing of three PSTVd RNA constructs in the yeast Saccharomyces cerevisiae Of these, only one form, a construct that adopts a previously described tetraloop-containing conformation (TL), produces circles. TL has 16 nucleotides of the 3' end duplicated at the 5' end and a 3' end produced by self-cleavage of a delta ribozyme. The other two constructs, an exact monomer flanked by ribozymes and a trihelix-forming RNA with requisite 5' and 3' duplications, do not produce circles. The TL circles contain nonnative nucleotides resulting from the 3' end created by the ribozyme and the 5' end created from an endolytic cleavage by yeast at a site distinct from where potato enzymes cut these RNAs. RNAs from all three transcripts are cleaved in places not on path for circle formation, likely representing RNA decay. We propose that these constructs fold into distinct RNA structures that interact differently with host cell RNA metabolism enzymes, resulting in various susceptibilities to degradation versus processing. We conclude that PSTVd RNA is opportunistic and may use different processing pathways in different hosts.IMPORTANCE In higher eukaryotes, the majority of transcribed RNAs do not encode proteins. These noncoding RNAs are responsible for mRNA regulation, control of the expression of regulatory microRNAs, sensing of changes in the environment by use of riboswitches (RNAs that change shape in response to environmental signals), catalysis, and more roles that are still being uncovered. Some of these functions may be remnants from the RNA world and, as such, would be part of the evolutionary past of all forms of modern life. Viroids are noncoding RNAs that can cause disease in plants. Since they encode no proteins, they depend on their own RNA and on host proteins for replication and pathogenicity. It is likely that viroids hijack critical host RNA pathways for processing the host's own noncoding RNA. These pathways are still unknown. Elucidating these pathways should reveal new biological functions of noncoding RNA.
Collapse
|
43
|
Nandy A, Saenz-Méndez P, Gorman AM, Samali A, Eriksson LA. Homology model of the human tRNA splicing ligase RtcB. Proteins 2017; 85:1983-1993. [PMID: 28707320 DOI: 10.1002/prot.25352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/28/2017] [Accepted: 07/11/2017] [Indexed: 12/25/2022]
Abstract
RtcB is an essential human tRNA ligase required for ligating the 2',3'-cyclic phosphate and 5'-hydroxyl termini of cleaved tRNA halves during tRNA splicing and XBP1 fragments during endoplasmic reticulum stress. Activation of XBP1 has been implicated in various human tumors including breast cancer. Here we present, for the first time, a homology model of human RtcB (hRtcB) in complex with manganese and covalently bound GMP built from the Pyrococcus horikoshii RtcB (bRtcB) crystal structure, PDB ID 4DWQA. The structure is analyzed in terms of stereochemical quality, folding reliability, secondary structure similarity with bRtcB, druggability of the active site binding pocket and its metal-binding microenvironment. In comparison with bRtcB, loss of a manganese-coordinating water and movement of Asn226 (Asn202 in 4DWQA) to form metal-ligand coordination, demonstrates the uniqueness of the hRtcB model. Rotation of GMP leads to the formation of an additional metal-ligand coordination (Mn-O). Umbrella sampling simulations of Mn binding in wild type and the catalytically inactive C122A mutant reveal a clear reduction of Mn binding ability in the mutant, thus explaining the loss of activity therein. Our results furthermore clearly show that the GTP binding site of the enzyme is a well-defined pocket that can be utilized as target site for in silico drug discovery.
Collapse
Affiliation(s)
- Argha Nandy
- Apoptosis Research Center, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Patricia Saenz-Méndez
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden.,Computational Chemistry and Biology Group, Facultad de Química, Universidad de la República, Montevideo, 11800, Uruguay
| | - Adrienne M Gorman
- Apoptosis Research Center, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Afshin Samali
- Apoptosis Research Center, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
| |
Collapse
|
44
|
Han W, Zhou C, Cheng J, Pan M, Hua Y, Zhao Y. Characterization and role of a 2',3'-cyclic phosphodiesterase from Deinococcus radiodurans. Biotechnol Lett 2017; 39:1211-1217. [PMID: 28497175 DOI: 10.1007/s10529-017-2349-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/04/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVES A 2',3'-cyclic phosphodiesterase gene (drCPDase) has been characterized from Deinococcus radiodurans and is involved in the robust resistance of this organism. RESULTS Cells lacking 2',3'-cyclic phosphodiesterase gene (drCPDase) showed modest growth defects and displayed increased sensitivities to high doses of various DNA-damaging agents including ionizing radiation, mitomycin C, UV and H2O2. The transcriptional level of drCPDase increased after H2O2 treatment. Additional nucleotide monophosphate partially recovered the phenotype of drCPDase knockout cells. Complementation of E. coli with drCPDase resulted in enhanced H2O2 resistance. CONCLUSIONS The 2',3'-cyclic phosphodiesterase (drCPDase) contributes to the extreme resistance of D. radiodurans and is presumably involved in damaged nucleotide detoxification.
Collapse
Affiliation(s)
- Wanchun Han
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Congli Zhou
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Jiahui Cheng
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Mingzhe Pan
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Yuejin Hua
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Ye Zhao
- Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China.
| |
Collapse
|
45
|
Abstract
An invitation to write a "Reflections" type of article creates a certain ambivalence: it is a great honor, but it also infers the end of your professional career. Before you vanish for good, your colleagues look forward to an interesting but entertaining account of the ups-and-downs of your past research and your views on science in general, peppered with indiscrete anecdotes about your former competitors and collaborators. What follows will disappoint those who await complaint and criticism, for example, about the difficulties of doing research in the 1960s and 1970s in Eastern Europe, or those seeking very personal revelations. My scientific life has in fact seen many happy coincidences, much good fortune, and several lucky escapes from situations that at the time were quite scary. I have also been fortunate with regard to competitors and collaborators, particularly because, whenever possible, I tried to "neutralize" my rivals by collaborating with them - to the benefit of all. I recommend this strategy to young researchers to dispel the nightmares that can occur when competing against powerful contenders. I have been blessed with the selection of my research topic: RNA biology. Over the last five decades, new and unexpected RNA-related phenomena emerged almost yearly. I experienced them very personally while studying transcription, translation, RNA splicing, ribosome biogenesis, and more recently, different classes of regulatory non-coding RNAs, including microRNAs. Some selected research and para-research stories, also covering many wonderful people I had a privilege to work with, are summarized below.
Collapse
Affiliation(s)
- Witold Filipowicz
- Friedrich Miescher Institute for Biomedical Research, Maulberstrasse 66, 4058 Basel, Switzerland.
| |
Collapse
|
46
|
Valach M, Moreira S, Faktorová D, Lukeš J, Burger G. Post-transcriptional mending of gene sequences: Looking under the hood of mitochondrial gene expression in diplonemids. RNA Biol 2016; 13:1204-1211. [PMID: 27715490 DOI: 10.1080/15476286.2016.1240143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The instructions to make proteins and structural RNAs are laid down in gene sequences. Yet, in certain instances, these primary instructions need to be modified considerably during gene expression, most often at the transcript level. Here we review a case of massive post-transcriptional revisions via trans-splicing and RNA editing, a phenomenon occurring in mitochondria of a recently recognized protist group, the diplonemids. As of now, the various post-transcriptional steps have been cataloged in detail, but how these processes function is still unknown. Since genetic manipulation techniques such as gene replacement and RNA interference have not yet been established for these organisms, alternative strategies have to be deployed. Here, we discuss the experimental and bioinformatics approaches that promise to unravel the molecular machineries of trans-splicing and RNA editing in Diplonema mitochondria.
Collapse
Affiliation(s)
- Matus Valach
- a Department of Biochemistry and Robert-Cedergren , Center for Bioinformatics and Genomics, Université de Montréal , Montreal , Canada
| | - Sandrine Moreira
- a Department of Biochemistry and Robert-Cedergren , Center for Bioinformatics and Genomics, Université de Montréal , Montreal , Canada
| | - Drahomíra Faktorová
- b Institute of Parasitology, Biology Center and Faculty of Sciences, University of South Bohemia , České Budějovice , Czech Republic
| | - Julius Lukeš
- b Institute of Parasitology, Biology Center and Faculty of Sciences, University of South Bohemia , České Budějovice , Czech Republic.,c Canadian Institute for Advanced Research , Toronto , Canada
| | - Gertraud Burger
- a Department of Biochemistry and Robert-Cedergren , Center for Bioinformatics and Genomics, Université de Montréal , Montreal , Canada
| |
Collapse
|
47
|
Abstract
The removal of transcriptional 5' and 3' extensions is an essential step in tRNA biogenesis. In some bacteria, tRNA 5'- and 3'-end maturation require no further steps, because all their genes encode the full tRNA sequence. Often however, the ends are incomplete, and additional maturation, repair or editing steps are needed. In all Eukarya, but also many Archaea and Bacteria, e.g., the universal 3'-terminal CCA is not encoded and has to be added by the CCA-adding enzyme. Apart from such widespread "repair/maturation" processes, tRNA genes in some cases apparently cannot give rise to intact, functional tRNA molecules without further, more specific end repair or editing. Interestingly, the responsible enzymes as far as identified appear to be polymerases usually involved in regular tRNA repair after damage. Alternatively, enzymes are recruited from other non-tRNA pathways; e.g., in animal mitochondria, poly(A) polymerase plays a crucial role in the 3'-end repair/editing of tRNAs. While these repair/editing pathways apparently allowed peculiar tRNA-gene overlaps or mismatching mutations in the acceptor stem to become genetically fixed in some present-day organisms, they may have also driven some global changes in tRNA maturation on a greater evolutionary scale.
Collapse
Affiliation(s)
- Christiane Rammelt
- a Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Walter Rossmanith
- b Center for Anatomy & Cell Biology, Medical University of Vienna , Vienna , Austria
| |
Collapse
|
48
|
Burroughs AM, Aravind L. RNA damage in biological conflicts and the diversity of responding RNA repair systems. Nucleic Acids Res 2016; 44:8525-8555. [PMID: 27536007 PMCID: PMC5062991 DOI: 10.1093/nar/gkw722] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/08/2016] [Indexed: 12/16/2022] Open
Abstract
RNA is targeted in biological conflicts by enzymatic toxins or effectors. A vast diversity of systems which repair or ‘heal’ this damage has only recently become apparent. Here, we summarize the known effectors, their modes of action, and RNA targets before surveying the diverse systems which counter this damage from a comparative genomics viewpoint. RNA-repair systems show a modular organization with extensive shuffling and displacement of the constituent domains; however, a general ‘syntax’ is strongly maintained whereby systems typically contain: a RNA ligase (either ATP-grasp or RtcB superfamilies), nucleotidyltransferases, enzymes modifying RNA-termini for ligation (phosphatases and kinases) or protection (methylases), and scaffold or cofactor proteins. We highlight poorly-understood or previously-uncharacterized repair systems and components, e.g. potential scaffolding cofactors (Rot/TROVE and SPFH/Band-7 modules) with their respective cognate non-coding RNAs (YRNAs and a novel tRNA-like molecule) and a novel nucleotidyltransferase associating with diverse ligases. These systems have been extensively disseminated by lateral transfer between distant prokaryotic and microbial eukaryotic lineages consistent with intense inter-organismal conflict. Components have also often been ‘institutionalized’ for non-conflict roles, e.g. in RNA-splicing and in RNAi systems (e.g. in kinetoplastids) which combine a distinct family of RNA-acting prim-pol domains with DICER-like proteins.
Collapse
Affiliation(s)
- A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| |
Collapse
|
49
|
Raasakka A, Myllykoski M, Laulumaa S, Lehtimäki M, Härtlein M, Moulin M, Kursula I, Kursula P. Determinants of ligand binding and catalytic activity in the myelin enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase. Sci Rep 2015; 5:16520. [PMID: 26563764 PMCID: PMC4643303 DOI: 10.1038/srep16520] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022] Open
Abstract
2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) is an enzyme highly abundant in the central nervous system myelin of terrestrial vertebrates. The catalytic domain of CNPase belongs to the 2H phosphoesterase superfamily and catalyzes the hydrolysis of nucleoside 2',3'-cyclic monophosphates to nucleoside 2'-monophosphates. The detailed reaction mechanism and the essential catalytic amino acids involved have been described earlier, but the roles of many amino acids in the vicinity of the active site have remained unknown. Here, several CNPase catalytic domain mutants were studied using enzyme kinetics assays, thermal stability experiments, and X-ray crystallography. Additionally, the crystal structure of a perdeuterated CNPase catalytic domain was refined at atomic resolution to obtain a detailed view of the active site and the catalytic mechanism. The results specify determinants of ligand binding and novel essential residues required for CNPase catalysis. For example, the aromatic side chains of Phe235 and Tyr168 are crucial for substrate binding, and Arg307 may affect active site electrostatics and regulate loop dynamics. The β5-α7 loop, unique for CNPase in the 2H phosphoesterase family, appears to have various functions in the CNPase reaction mechanism, from coordinating the nucleophilic water molecule to providing a binding pocket for the product and being involved in product release.
Collapse
Affiliation(s)
- Arne Raasakka
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
| | - Matti Myllykoski
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
- European Spallation Source (ESS), Lund, Sweden
| | - Mari Lehtimäki
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | | | - Inari Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
| |
Collapse
|
50
|
Desai KK, Beltrame AL, Raines RT. Coevolution of RtcB and Archease created a multiple-turnover RNA ligase. RNA (NEW YORK, N.Y.) 2015; 21:1866-1872. [PMID: 26385509 PMCID: PMC4604427 DOI: 10.1261/rna.052639.115] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/06/2015] [Indexed: 06/05/2023]
Abstract
RtcB is a noncanonical RNA ligase that joins either 2',3'-cyclic phosphate or 3'-phosphate termini to 5'-hydroxyl termini. The genes encoding RtcB and Archease constitute a tRNA splicing operon in many organisms. Archease is a cofactor of RtcB that accelerates RNA ligation and alters the NTP specificity of the ligase from Pyrococcus horikoshii. Yet, not all organisms that encode RtcB also encode Archease. Here we sought to understand the differences between Archease-dependent and Archease-independent RtcBs so as to illuminate the evolution of Archease and its function. We report on the Archease-dependent RtcB from Thermus thermophilus and the Archease-independent RtcB from Thermobifida fusca. We find that RtcB from T. thermophilus can catalyze multiple turnovers only in the presence of Archease. Remarkably, Archease from P. horikoshii can activate T. thermophilus RtcB, despite low sequence identity between the Archeases from these two organisms. In contrast, RtcB from T. fusca is a single-turnover enzyme that is unable to be converted into a multiple-turnover ligase by Archease from either P. horikoshii or T. thermophilus. Thus, our data indicate that Archease likely evolved to support multiple-turnover activity of RtcB and that coevolution of the two proteins is necessary for a functional interaction.
Collapse
Affiliation(s)
- Kevin K Desai
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Amanda L Beltrame
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Ronald T Raines
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|