1
|
Fisher AJ, Beal PA. Structural perspectives on adenosine to inosine RNA editing by ADARs. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102284. [PMID: 39165563 PMCID: PMC11334849 DOI: 10.1016/j.omtn.2024.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Adenosine deaminases acting on RNA (ADARs) are enzymes that catalyze the hydrolytic deamination of adenosine to inosine. The editing feature of ADARs has garnered much attention as a therapeutic tool to repurpose ADARs to correct disease-causing mutations at the mRNA level in a technique called site-directed RNA editing (SDRE). Administering a short guide RNA oligonucleotide that hybridizes to a mutant sequence forms the requisite dsRNA substrate, directing ADARs to edit the desired adenosine. However, much is still unknown about ADARs' selectivity and sequence-specific effects on editing. Atomic-resolution structures can help provide additional insight to ADARs' selectivity and lead to novel guide RNA designs. Indeed, recent structures of ADAR domains have expanded our understanding on RNA binding and the base-flipping catalytic mechanism. These efforts have enabled the rational design of improved ADAR guide strands and advanced the therapeutic potential of the SDRE approach. While no full-length structure of any ADAR is known, this review presents an exposition of the structural basis for function of the different ADAR domains, focusing on human ADAR2. Key insights are extrapolated to human ADAR1, which is of substantial interest because of its widespread expression in most human tissues.
Collapse
Affiliation(s)
- Andrew J. Fisher
- Department of Chemistry, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - Peter A. Beal
- Department of Chemistry, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| |
Collapse
|
2
|
Grypioti E, Richard H, Kryovrysanaki N, Jaubert M, Falciatore A, Verret F, Kalantidis K. Dicer-dependent heterochromatic small RNAs in the model diatom species Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2024; 241:811-826. [PMID: 38044751 DOI: 10.1111/nph.19429] [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: 09/06/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023]
Abstract
Diatoms are eukaryotic microalgae responsible for nearly half of the marine productivity. RNA interference (RNAi) is a mechanism of regulation of gene expression mediated by small RNAs (sRNAs) processed by the endoribonuclease Dicer (DCR). To date, the mechanism and physiological role of RNAi in diatoms are unknown. We mined diatom genomes and transcriptomes for key RNAi effectors and retraced their phylogenetic history. We generated DCR knockout lines in the model diatom species Phaeodactylum tricornutum and analyzed their mRNA and sRNA populations, repression-associated histone marks, and acclimatory response to nitrogen starvation. Diatoms presented a diversification of key RNAi effectors whose distribution across species suggests the presence of distinct RNAi pathways. P. tricornutum DCR was found to process 26-31-nt-long double-stranded sRNAs originating mostly from transposons covered by repression-associated epigenetic marks. In parallel, P. tricornutum DCR was necessary for the maintenance of the repression-associated histone marks H3K9me2/3 and H3K27me3. Finally, PtDCR-KO lines presented a compromised recovery post nitrogen starvation suggesting a role for P. tricornutum DCR in the acclimation to nutrient stress. Our study characterized the molecular function of the single DCR homolog of P. tricornutum suggesting an association between RNAi and heterochromatin maintenance in this model diatom species.
Collapse
Affiliation(s)
- Emilia Grypioti
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
| | - Hugues Richard
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Bioinformatics Unit, Genome Competence Center (MF1), Robert Koch Institute, 13353, Berlin, Germany
| | - Nikoleta Kryovrysanaki
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
| | - Marianne Jaubert
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Angela Falciatore
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Frédéric Verret
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
| | - Kriton Kalantidis
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
| |
Collapse
|
3
|
Sequence determinant of small RNA production by DICER. Nature 2023; 615:323-330. [PMID: 36813957 DOI: 10.1038/s41586-023-05722-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 01/11/2023] [Indexed: 02/24/2023]
Abstract
RNA silencing relies on specific and efficient processing of double-stranded RNA by Dicer, which yields microRNAs (miRNAs) and small interfering RNAs (siRNAs)1,2. However, our current knowledge of the specificity of Dicer is limited to the secondary structures of its substrates: a double-stranded RNA of approximately 22 base pairs with a 2-nucleotide 3' overhang and a terminal loop3-11. Here we found evidence pointing to an additional sequence-dependent determinant beyond these structural properties. To systematically interrogate the features of precursor miRNAs (pre-miRNAs), we carried out massively parallel assays with pre-miRNA variants and human DICER (also known as DICER1). Our analyses revealed a deeply conserved cis-acting element, termed the 'GYM motif' (paired G, paired pyrimidine and mismatched C or A), near the cleavage site. The GYM motif promotes processing at a specific position and can override the previously identified 'ruler'-like counting mechanisms from the 5' and 3' ends of pre-miRNA3-6. Consistently, integrating this motif into short hairpin RNA or Dicer-substrate siRNA potentiates RNA interference. Furthermore, we find that the C-terminal double-stranded RNA-binding domain (dsRBD) of DICER recognizes the GYM motif. Alterations in the dsRBD reduce processing and change cleavage sites in a motif-dependent fashion, affecting the miRNA repertoire in cells. In particular, the cancer-associated R1855L substitution in the dsRBD strongly impairs GYM motif recognition. This study uncovers an ancient principle of substrate recognition by metazoan Dicer and implicates its potential in the design of RNA therapeutics.
Collapse
|
4
|
Structure of the human DICER-pre-miRNA complex in a dicing state. Nature 2023; 615:331-338. [PMID: 36813958 DOI: 10.1038/s41586-023-05723-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 12/14/2022] [Indexed: 02/24/2023]
Abstract
Dicer has a key role in small RNA biogenesis, processing double-stranded RNAs (dsRNAs)1,2. Human DICER (hDICER, also known as DICER1) is specialized for cleaving small hairpin structures such as precursor microRNAs (pre-miRNAs) and has limited activity towards long dsRNAs-unlike its homologues in lower eukaryotes and plants, which cleave long dsRNAs. Although the mechanism by which long dsRNAs are cleaved has been well documented, our understanding of pre-miRNA processing is incomplete because structures of hDICER in a catalytic state are lacking. Here we report the cryo-electron microscopy structure of hDICER bound to pre-miRNA in a dicing state and uncover the structural basis of pre-miRNA processing. hDICER undergoes large conformational changes to attain the active state. The helicase domain becomes flexible, which allows the binding of pre-miRNA to the catalytic valley. The double-stranded RNA-binding domain relocates and anchors pre-miRNA in a specific position through both sequence-independent and sequence-specific recognition of the newly identified 'GYM motif'3. The DICER-specific PAZ helix is also reoriented to accommodate the RNA. Furthermore, our structure identifies a configuration of the 5' end of pre-miRNA inserted into a basic pocket. In this pocket, a group of arginine residues recognize the 5' terminal base (disfavouring guanine) and terminal monophosphate; this explains the specificity of hDICER and how it determines the cleavage site. We identify cancer-associated mutations in the 5' pocket residues that impair miRNA biogenesis. Our study reveals how hDICER recognizes pre-miRNAs with stringent specificity and enables a mechanistic understanding of hDICER-related diseases.
Collapse
|
5
|
Hauk P, Weeks R, Ostermeier M. A CRISPR-dCas9 System for Assaying and Selecting for RNase III Activity In Vivo in Escherichia coli. CRISPR J 2023; 6:43-51. [PMID: 36493370 DOI: 10.1089/crispr.2022.0041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ribonuclease III (RNase III) and RNase III-like ribonucleases have a wide range of important functions and are found in all organisms, yet a simple and high-throughput in vivo method for measuring RNase III activity does not exist. Typical methods for measuring RNase III activity rely on in vitro RNA analysis or in vivo methods that are not suitable for high-throughput analysis. In this study, we describe our development of a deactivated Cas9 (dCas9)-based in vivo assay for RNase III activity that utilizes RNase III's cleavage of the 5'-untranslated region (UTR) of its own messenger RNA. The key molecule in the system is a hybrid guide RNA (gRNA) between the 5'-UTR of RNase III and gGFP, a gRNA that works with dCas9 to repress GFP expression. This fusion must be cleaved by RNase III for full GFP repression. Our system uses GFP fluorescence to report on Escherichia coli RNase III activity in culture and on an individual cell basis, making it effective for selecting individual cells through fluorescence-activated cell sorting. Homology between enzymes within the RNase III family suggests this assay might be adapted to measure the activity of other enzymes in the RNase III family such as human Dicer or Drosha.
Collapse
Affiliation(s)
- Pricila Hauk
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ryan Weeks
- Chemistry-Biology Interface Graduate Program, Johns Hopkins University, Baltimore, Maryland, USA
| | - Marc Ostermeier
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
6
|
Torrez RM, Ohi MD, Garner AL. Structural Insights into the Advances and Mechanistic Understanding of Human Dicer. Biochemistry 2023; 62:1-16. [PMID: 36534787 DOI: 10.1021/acs.biochem.2c00570] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The RNase III endoribonuclease Dicer was discovered to be associated with cleavage of double-stranded RNA in 2001. Since then, many advances in our understanding of Dicer function have revealed that the enzyme plays a major role not only in microRNA biology but also in multiple RNA interference-related pathways. Yet, there is still much to be learned regarding Dicer structure-function in relation to how Dicer and Dicer-like enzymes initiate their cleavage reaction and release the desired RNA product. This Perspective describes the latest advances in Dicer structural studies, expands on what we have learned from this data, and outlines key gaps in knowledge that remain to be addressed. More specifically, we focus on human Dicer and highlight the intermediate processing steps where there is a lack of structural data to understand how the enzyme traverses from pre-cleavage to cleavage-competent states. Understanding these details is necessary to model Dicer's function as well as develop more specific microRNA-targeted therapeutics for the treatment of human diseases.
Collapse
Affiliation(s)
- Rachel M Torrez
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, United States
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109, United States
| | - Melanie D Ohi
- Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109, United States
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, Michigan 48109, United States
| | - Amanda L Garner
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
7
|
Su S, Wang J, Deng T, Yuan X, He J, Liu N, Li X, Huang Y, Wang HW, Ma J. Structural insights into dsRNA processing by Drosophila Dicer-2-Loqs-PD. Nature 2022; 607:399-406. [PMID: 35768513 PMCID: PMC9279154 DOI: 10.1038/s41586-022-04911-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 05/25/2022] [Indexed: 12/21/2022]
Abstract
Small interfering RNAs (siRNAs) are the key components for RNA interference (RNAi), a conserved RNA-silencing mechanism in many eukaryotes1,2. In Drosophila, an RNase III enzyme Dicer-2 (Dcr-2), aided by its cofactor Loquacious-PD (Loqs-PD), has an important role in generating 21 bp siRNA duplexes from long double-stranded RNAs (dsRNAs)3,4. ATP hydrolysis by the helicase domain of Dcr-2 is critical to the successful processing of a long dsRNA into consecutive siRNA duplexes5,6. Here we report the cryo-electron microscopy structures of Dcr-2-Loqs-PD in the apo state and in multiple states in which it is processing a 50 bp dsRNA substrate. The structures elucidated interactions between Dcr-2 and Loqs-PD, and substantial conformational changes of Dcr-2 during a dsRNA-processing cycle. The N-terminal helicase and domain of unknown function 283 (DUF283) domains undergo conformational changes after initial dsRNA binding, forming an ATP-binding pocket and a 5'-phosphate-binding pocket. The overall conformation of Dcr-2-Loqs-PD is relatively rigid during translocating along the dsRNA in the presence of ATP, whereas the interactions between the DUF283 and RIIIDb domains prevent non-specific cleavage during translocation by blocking the access of dsRNA to the RNase active centre. Additional ATP-dependent conformational changes are required to form an active dicing state and precisely cleave the dsRNA into a 21 bp siRNA duplex as confirmed by the structure in the post-dicing state. Collectively, this study revealed the molecular mechanism for the full cycle of ATP-dependent dsRNA processing by Dcr-2-Loqs-PD.
Collapse
Affiliation(s)
- Shichen Su
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
| | - Jia Wang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ting Deng
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
| | - Xun Yuan
- Shanghai Key Laboratory of Biliary Tract Disease Research, Shanghai Research Center of Biliary Tract Disease, Department of General Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinqiu He
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
| | - Nan Liu
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaomin Li
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ying Huang
- Shanghai Key Laboratory of Biliary Tract Disease Research, Shanghai Research Center of Biliary Tract Disease, Department of General Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, China.
| |
Collapse
|
8
|
Crystal structures and insights into precursor tRNA 5'-end processing by prokaryotic minimal protein-only RNase P. Nat Commun 2022; 13:2290. [PMID: 35484139 PMCID: PMC9051087 DOI: 10.1038/s41467-022-30072-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 03/30/2022] [Indexed: 11/08/2022] Open
Abstract
Besides the canonical RNA-based RNase P, pre-tRNA 5’-end processing can also be catalyzed by protein-only RNase P (PRORP). To date, various PRORPs have been discovered, but the basis underlying substrate binding and cleavage by HARPs (homolog of Aquifex RNase P) remains elusive. Here, we report structural and biochemical studies of HARPs. Comparison of the apo- and pre-tRNA-complexed structures showed that HARP is able to undergo large conformational changes that facilitate pre-tRNA binding and catalytic site formation. Planctomycetes bacterium HARP exists as dimer in vitro, but gel filtration and electron microscopy analysis confirmed that HARPs from Thermococcus celer, Thermocrinis minervae and Thermocrinis ruber can assemble into larger oligomers. Structural analysis, mutagenesis and in vitro biochemical studies all supported one cooperative pre-tRNA processing mode, in which one HARP dimer binds pre-tRNA at the elbow region whereas 5’-end removal is catalyzed by the partner dimer. Our studies significantly advance our understanding on pre-tRNA processing by PRORPs. HARP are member of protein-only RNase P, which catalyzes pre-tRNA 5’-end processing and maturation. Here, the authors present crystal structure and provide mechanistic insights into pre-tRNA binding and cleavage by HARP proteins.
Collapse
|
9
|
Paithankar H, Tarang GS, Parvez F, Marathe A, Joshi M, Chugh J. Inherent conformational plasticity in dsRBDs enables interaction with topologically distinct RNAs. Biophys J 2022; 121:1038-1055. [PMID: 35134335 PMCID: PMC8943759 DOI: 10.1016/j.bpj.2022.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 12/25/2021] [Accepted: 02/03/2022] [Indexed: 11/02/2022] Open
Abstract
Many double-stranded RNA-binding domains (dsRBDs) interact with topologically distinct dsRNAs in biological pathways pivotal to viral replication, cancer causation, neurodegeneration, and so on. We hypothesized that the adaptability of dsRBDs is essential to target different dsRNA substrates. A model dsRBD and a few dsRNAs, slightly different in shape from each other, were used to test the systematic shape dependence of RNA on the dsRBD-binding using nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. NMR-based titrations showed a distinct binding pattern for the dsRBD with the topologically distinct dsRNAs. The line broadening upon RNA binding was observed to cluster in the residues lying in close proximity, thereby suggesting an RNA-induced conformational exchange in the dsRBD. Further, while the intrinsic microsecond dynamics observed in the apo-dsRBD were found to quench upon binding with the dsRNA, the microsecond dynamics got induced at residues spatially proximal to quench sites upon binding with the dsRNA. This apparent relay of conformational exchange suggests the significance of intrinsic dynamics to help adapt the dsRBD to target various dsRNA-shapes. The conformational pool visualized in MD simulations for the apo-dsRBD reported here has also been observed to sample the conformations seen previously for various dsRBDs in apo- and in dsRNA-bound state structures, further suggesting the conformational adaptability of the dsRBDs. These investigations provide a dynamic basis for the substrate promiscuity for dsRBD proteins.
Collapse
Affiliation(s)
- Harshad Paithankar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India
| | - Guneet Singh Tarang
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India
| | - Firdousi Parvez
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India
| | - Aniket Marathe
- Bioinformatics Center, Savitrabai Phule Pune University, Pune, Maharashtra, India
| | - Manali Joshi
- Bioinformatics Center, Savitrabai Phule Pune University, Pune, Maharashtra, India
| | - Jeetender Chugh
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India; Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
| |
Collapse
|
10
|
Dharavath S, Shaw GX, Ji X. Structural basis for Dicer-like function of an engineered RNase III variant and insights into the reaction trajectory of two-Mg 2+-ion catalysis. RNA Biol 2022; 19:908-915. [PMID: 35829618 PMCID: PMC9291653 DOI: 10.1080/15476286.2022.2099650] [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] [Indexed: 10/27/2022] Open
Abstract
The RNase III family of dsRNA-specific endonucleases is exemplified by prokaryotic RNase III and eukaryotic Rnt1p, Drosha, and Dicer. Structures of Aquifex aeolicus RNase III (AaRNase III) and Saccharomyces cerevisiae Rnt1p (ScRnt1p) show that both enzymes recognize substrates in a sequence-specific manner and propel RNA hydrolysis by two-Mg2+-ion catalysis. Previously, we created an Escherichia coli RNase III variant (EcEEQ) by eliminating the sequence specificity via protein engineering and called it bacterial Dicer for the fact that it produces heterogeneous small interfering RNA cocktails. Here, we present a 1.8-Å crystal structure of a postcleavage complex of EcEEQ, representing a reaction state immediately after the cleavage of scissile bond. The structure not only establishes the structure-and-function relationship of EcEEQ, but also reveals the functional role of a third Mg2+ ion that is involved in RNA hydrolysis by bacterial RNase III. In contrast, the cleavage site assembly of ScRnt1p does not contain a third Mg2+ ion. Instead, it involves two more amino acid side chains conserved among eukaryotic RNase IIIs. We conclude that the EcEEQ structure (this work) represents the cleavage assembly of prokaryotic RNase IIIs and the ScRnt1p structure (PDB: 4OOG), also determined at the postcleavage state, represents the cleavage assembly of eukaryotic RNase IIIs. Together, these two structures provide insights into the reaction trajectory of two-Mg2+-ion catalysis by prokaryotic and eukaryotic RNase III enzymes.
Collapse
Affiliation(s)
- Sudhaker Dharavath
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
| | - Gary X Shaw
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
| | - Xinhua Ji
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
| |
Collapse
|
11
|
Wang Q, Xue Y, Zhang L, Zhong Z, Feng S, Wang C, Xiao L, Yang Z, Harris CJ, Wu Z, Zhai J, Yang M, Li S, Jacobsen SE, Du J. Mechanism of siRNA production by a plant Dicer-RNA complex in dicing-competent conformation. Science 2021; 374:1152-1157. [PMID: 34648373 PMCID: PMC8682726 DOI: 10.1126/science.abl4546] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In eukaryotes, small RNAs (sRNAs) play critical roles in multiple biological processes. Dicer endonucleases are a central part of sRNA biogenesis. In plants, DICER-LIKE PROTEIN 3 (DCL3) produces 24-nucleotide (nt) small interfering RNAs (siRNAs) that determine the specificity of the RNA-directed DNA methylation pathway. Here, we determined the structure of a DCL3–pre-siRNA complex in an active dicing-competent state. The 5′-phosphorylated A1 of the guide strand and the 1-nt 3′ overhang of the complementary strand are specifically recognized by a positively charged pocket and an aromatic cap, respectively. The 24-nt siRNA length dependence relies on the separation between the 5′-phosphorylated end of the guide RNA and dual cleavage sites formed by the paired ribonuclease III domains. These structural studies, complemented by functional data, provide insight into the dicing principle for Dicers in general.
Collapse
Affiliation(s)
- Qian Wang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yan Xue
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Laixing Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhenhui Zhong
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Changshi Wang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Lifan Xiao
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Zhenlin Yang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - C. Jake Harris
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Zhe Wu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jixian Zhai
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Sisi Li
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Health Science Center, Shenzhen, 518060, China,Co-corresponding authors: Jiamu Du (); Steven E. Jacobsen (); Sisi Li ()
| | - Steven E. Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095,Co-corresponding authors: Jiamu Du (); Steven E. Jacobsen (); Sisi Li ()
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.,Co-corresponding authors: Jiamu Du (); Steven E. Jacobsen (); Sisi Li ()
| |
Collapse
|
12
|
Naganathan A, Keltz R, Lyon H, Culver GM. Uncovering a delicate balance between endonuclease RNase III and ribosomal protein S15 in E. coli ribosome assembly. Biochimie 2021; 191:104-117. [PMID: 34508826 DOI: 10.1016/j.biochi.2021.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 08/26/2021] [Accepted: 09/02/2021] [Indexed: 12/01/2022]
Abstract
The bacterial ribosomal protein S15 is located in the platform, a functional region of the 30S ribosomal subunit. While S15 is critical for in vitro formation of E. coli small subunits (SSUs), it is dispensable for in vivo biogenesis and growth. In this work, a novel synergistic interaction between rpsO, the gene that encodes S15, and rnc (the gene that encodes RNase III), was uncovered in E. coli. RNase III catalyzes processing of precursor ribosomal RNA (rRNA) transcripts and thus is involved in functional ribosome subunit maturation. Strains lacking S15 (ΔrpsO), RNase III (Δrnc) or both genes were examined to understand the relationship between these two factors and the impact of this double deletion on rRNA processing and SSU maturation. The double deletion of rpsO and rnc partially alleviates the observed cold sensitivity of ΔrpsO alone. A novel 16S rRNA precursor (17S∗ rRNA) that is detected in free 30S subunits of Δrnc is incorporated in 70S-like ribosomes in the double deletion. The stable accumulation of 17S∗ rRNA suggests that timing of processing events is closely coupled with SSU formation events in vivo. The double deletion has a suppressive effect on the cell elongation phenotype of ΔrpsO. The alteration of the phenotypes associated with S15 loss, due to the absence of RNase III, indicates that pre-rRNA processing and improvement of growth, relative to that observed for ΔrpsO, are connected. The characterization of the functional link between the two factors illustrates that there are redundancies and compensatory pathways for SSU maturation.
Collapse
Affiliation(s)
| | - Roxanne Keltz
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Hiram Lyon
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Gloria M Culver
- Department of Biology, University of Rochester, Rochester, NY, USA; Center for RNA Biology, University of Rochester, Rochester, NY, USA; Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
13
|
RNase III and RNase E Influence Posttranscriptional Regulatory Networks Involved in Virulence Factor Production, Metabolism, and Regulatory RNA Processing in Bordetella pertussis. mSphere 2021; 6:e0065021. [PMID: 34406853 PMCID: PMC8386462 DOI: 10.1128/msphere.00650-21] [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] [Indexed: 11/20/2022] Open
Abstract
Bordetella pertussis has been shown to encode regulatory RNAs, yet the posttranscriptional regulatory circuits on which they act remain to be fully elucidated. We generated mutants lacking the endonucleases RNase III and RNase E and assessed their individual impact on the B. pertussis transcriptome. Transcriptome sequencing (RNA-Seq) analysis showed differential expression of ∼25% of the B. pertussis transcriptome in each mutant, with only 28% overlap between data sets. Both endonucleases exhibited substantial impact on genes involved in amino acid uptake (e.g., ABC transporters) and in virulence (e.g., the type III secretion system and the autotransporters vag8, tcfA, and brkA). Interestingly, mutations in RNase III and RNase E drove the stability of many transcripts, including those involved in virulence, in opposite directions, a result that was validated by qPCR and immunoblotting for tcfA and brkA. Of note, whereas similar mutations to RNase E in Escherichia coli have subtle effects on transcript stability, a striking >20-fold reduction in four gene transcripts, including tcfA and vag8, was observed in B. pertussis. We further compared our data set to the regulon controlled by the RNA chaperone Hfq to identify B. pertussis loci influenced by regulatory RNAs. This analysis identified ∼120 genes and 19 operons potentially regulated at the posttranscriptional level. Thus, our findings revealed how changes in RNase III- and RNase E-mediated RNA turnover influence pathways associated with virulence and cellular homeostasis. Moreover, we highlighted loci potentially influenced by regulatory RNAs, providing insights into the posttranscriptional regulatory networks involved in fine-tuning B. pertussis gene expression. IMPORTANCE Noncoding, regulatory RNAs in bacterial pathogens are critical components required for rapid changes in gene expression profiles. However, little is known about the role of regulatory RNAs in the growth and pathogenesis of Bordetella pertussis. To address this, mutants separately lacking ribonucleases central to regulatory RNA processing, RNase III and RNase E, were analyzed by RNA-Seq. Here, we detail the first transcriptomic analysis of the impact of altered RNA degradation in B. pertussis. Each mutant showed approximately 1,000 differentially expressed genes, with significant changes in the expression of pathways associated with metabolism, bacterial secretion, and virulence factor production. Our analysis suggests an important role for these ribonucleases during host colonization and provides insights into the breadth of posttranscriptional regulation in B. pertussis, further informing our understanding of B. pertussis pathogenesis.
Collapse
|
14
|
Wang L, Poque S, Laamanen K, Saarela J, Poso A, Laitinen T, Valkonen JPT. In Vitro Identification and In Vivo Confirmation of Inhibitors for Sweet Potato Chlorotic Stunt Virus RNA Silencing Suppressor, a Viral RNase III. J Virol 2021; 95:e00107-21. [PMID: 33827953 PMCID: PMC8315922 DOI: 10.1128/jvi.00107-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/28/2021] [Indexed: 11/20/2022] Open
Abstract
Sweet potato virus disease (SPVD), caused by synergistic infection of Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato feathery mottle virus (SPFMV), is responsible for substantial yield losses all over the world. However, there are currently no approved treatments for this severe disease. The crucial role played by RNase III of SPCSV (CSR3) as an RNA silencing suppressor during the viruses' synergistic interaction in sweetpotato makes it an ideal drug target for developing antiviral treatment. In this study, high-throughput screening (HTS) of small molecular libraries targeting CSR3 was initiated by a virtual screen using Glide docking, allowing the selection of 6,400 compounds out of 136,353. We subsequently developed and carried out kinetic-based HTS using fluorescence resonance energy transfer technology, which isolated 112 compounds. These compounds were validated with dose-response assays including kinetic-based HTS and binding affinity assays using surface plasmon resonance and microscale thermophoresis. Finally, the interference of the selected compounds with viral accumulation was verified in planta In summary, we identified five compounds belonging to two structural classes that inhibited CSR3 activity and reduced viral accumulation in plants. These results provide the foundation for developing antiviral agents targeting CSR3 to provide new strategies for controlling sweetpotato virus diseases.IMPORTANCE We report here a high-throughput inhibitor identification method that targets a severe sweetpotato virus disease caused by coinfection with two viruses (SPCSV and SPFMV). The disease is responsible for up to 90% yield losses. Specifically, we targeted the RNase III enzyme encoded by SPCSV, which plays an important role in suppressing the RNA silencing defense system of sweetpotato plants. Based on virtual screening, laboratory assays, and confirmation in planta, we identified five compounds that could be used to develop antiviral drugs to combat the most severe sweetpotato virus disease.
Collapse
Affiliation(s)
- Linping Wang
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Sylvain Poque
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Karoliina Laamanen
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Jani Saarela
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Antti Poso
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
- Department of Internal Medicine VIII, University Hospital Tübingen, Tübingen, Germany
| | - Tuomo Laitinen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Jari P T Valkonen
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| |
Collapse
|
15
|
Cánovas-Márquez JT, Falk S, Nicolás FE, Padmanabhan S, Zapata-Pérez R, Sánchez-Ferrer Á, Navarro E, Garre V. A ribonuclease III involved in virulence of Mucorales fungi has evolved to cut exclusively single-stranded RNA. Nucleic Acids Res 2021; 49:5294-5307. [PMID: 33877360 PMCID: PMC8136814 DOI: 10.1093/nar/gkab238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 02/16/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
Members of the ribonuclease III (RNase III) family regulate gene expression by processing double-stranded RNA (dsRNA). This family includes eukaryotic Dicer and Drosha enzymes that generate small dsRNAs in the RNA interference (RNAi) pathway. The fungus Mucor lusitanicus, which causes the deadly infection mucormycosis, has a complex RNAi system encompassing a non-canonical RNAi pathway (NCRIP) that regulates virulence by degrading specific mRNAs. In this pathway, Dicer function is replaced by R3B2, an atypical class I RNase III, and small single-stranded RNAs (ssRNAs) are produced instead of small dsRNA as Dicer-dependent RNAi pathways. Here, we show that R3B2 forms a homodimer that binds to ssRNA and dsRNA molecules, but exclusively cuts ssRNA, in contrast to all known RNase III. The dsRNA cleavage inability stems from its unusual RNase III domain (RIIID) because its replacement by a canonical RIIID allows dsRNA processing. A crystal structure of R3B2 RIIID resembles canonical RIIIDs, despite the low sequence conservation. However, the groove that accommodates dsRNA in canonical RNases III is narrower in the R3B2 homodimer, suggesting that this feature could be responsible for the cleavage specificity for ssRNA. Conservation of this activity in R3B2 proteins from other mucormycosis-causing Mucorales fungi indicates an early evolutionary acquisition.
Collapse
Affiliation(s)
- José Tomás Cánovas-Márquez
- Department of Genetics and Microbiology (Associated Unit to IQFR-CSIC), Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| | - Sebastian Falk
- Department of Structural and Computational Biology, Max Perutz Labs, A-1030 Vienna, Austria
| | - Francisco E Nicolás
- Department of Genetics and Microbiology (Associated Unit to IQFR-CSIC), Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| | - Subramanian Padmanabhan
- Instituto de Química Física “Rocasolano,” Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
| | - Rubén Zapata-Pérez
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum,” University of Murcia, Campus Espinardo, 30100, Murcia, Spain
| | - Álvaro Sánchez-Ferrer
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum,” University of Murcia, Campus Espinardo, 30100, Murcia, Spain
| | - Eusebio Navarro
- Department of Genetics and Microbiology (Associated Unit to IQFR-CSIC), Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| | - Victoriano Garre
- Department of Genetics and Microbiology (Associated Unit to IQFR-CSIC), Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| |
Collapse
|
16
|
Paturi S, Deshmukh MV. A Glimpse of "Dicer Biology" Through the Structural and Functional Perspective. Front Mol Biosci 2021; 8:643657. [PMID: 34026825 PMCID: PMC8138440 DOI: 10.3389/fmolb.2021.643657] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/07/2021] [Indexed: 01/05/2023] Open
Abstract
The RNA interference pathway (RNAi) is executed by two core enzymes, Dicer and Argonaute, for accomplishing a tailored transcriptional and post-transcriptional gene regulation. Dicer, an RNase III enzyme, initiates the RNAi pathway, plays a pivotal role in fighting infection against pathogens, and acts as a housekeeping enzyme for cellular homeostasis. Here, we review structure-based functional insights of Dicer and its domains present in a diverse group of organisms. Although Dicer and its domains are evolutionarily conserved from microsporidian parasites to humans, recent cryo-electron microscopy structures of Homo sapiens Dicer and Drosophila melanogaster Dicer-2 suggest characteristic variations in the mechanism of the dsRNA substrate recognition. Interestingly, the necessity for more than one functionally distinct Dicer paralogs in insects and plants compared with a single Dicer in other eukaryotic life forms implies Dicer’s role in the interplay of RNAi and other defense mechanisms. Based on the structural and mechanistic information obtained during the last decade, we aim to highlight the significance of key Dicer domains that are crucial to Dicer specific recognition and precise cleavage of dsRNA substrates. Further, the role of Dicer in the formation of Argonaute-based RNA-induced silencing complex (RISC) assembly formation, Dicer’s ability to regulate a complex protein interaction network, and its role in other cellular processes, as well as its therapeutic potentials, are emphasized.
Collapse
Affiliation(s)
- Sneha Paturi
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | - Mandar V Deshmukh
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| |
Collapse
|
17
|
Singh RK, Jonely M, Leslie E, Rejali NA, Noriega R, Bass BL. Transient kinetic studies of the antiviral Drosophila Dicer-2 reveal roles of ATP in self-nonself discrimination. eLife 2021; 10:65810. [PMID: 33787495 PMCID: PMC8079148 DOI: 10.7554/elife.65810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/31/2021] [Indexed: 11/25/2022] Open
Abstract
Some RIG-I-like receptors (RLRs) discriminate viral and cellular dsRNA by their termini, and Drosophila melanogaster Dicer-2 (dmDcr-2) differentially processes dsRNA with blunt or 2 nucleotide 3’-overhanging termini. We investigated the transient kinetic mechanism of the dmDcr-2 reaction using a rapid reaction stopped-flow technique and time-resolved fluorescence spectroscopy. Indeed, we found that ATP binding to dmDcr-2’s helicase domain impacts association and dissociation kinetics of dsRNA in a termini-dependent manner, revealing termini-dependent discrimination of dsRNA on a biologically relevant time scale (seconds). ATP hydrolysis promotes transient unwinding of dsRNA termini followed by slow rewinding, and directional translocation of the enzyme to the cleavage site. Time-resolved fluorescence anisotropy reveals a nucleotide-dependent modulation in conformational fluctuations (nanoseconds) of the helicase and Platform–PAZ domains that is correlated with termini-dependent dsRNA cleavage. Our study offers a kinetic framework for comparison to other Dicers, as well as all members of the RLRs involved in innate immunity.
Collapse
Affiliation(s)
- Raushan K Singh
- Department of Biochemistry, University of Utah, Salt Lake City, United States
| | - McKenzie Jonely
- Department of Chemistry, University of Utah, Salt Lake City, United States
| | - Evan Leslie
- Department of Biochemistry, University of Utah, Salt Lake City, United States
| | - Nick A Rejali
- Department of Pathology, University of Utah, Salt Lake City, United States
| | - Rodrigo Noriega
- Department of Chemistry, University of Utah, Salt Lake City, United States
| | - Brenda L Bass
- Department of Biochemistry, University of Utah, Salt Lake City, United States
| |
Collapse
|
18
|
Wencker FDR, Marincola G, Schoenfelder SMK, Maaß S, Becher D, Ziebuhr W. Another layer of complexity in Staphylococcus aureus methionine biosynthesis control: unusual RNase III-driven T-box riboswitch cleavage determines met operon mRNA stability and decay. Nucleic Acids Res 2021; 49:2192-2212. [PMID: 33450025 PMCID: PMC7913692 DOI: 10.1093/nar/gkaa1277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/18/2020] [Accepted: 01/08/2021] [Indexed: 11/12/2022] Open
Abstract
In Staphylococcus aureus, de novo methionine biosynthesis is regulated by a unique hierarchical pathway involving stringent-response controlled CodY repression in combination with a T-box riboswitch and RNA decay. The T-box riboswitch residing in the 5′ untranslated region (met leader RNA) of the S. aureus metICFE-mdh operon controls downstream gene transcription upon interaction with uncharged methionyl-tRNA. met leader and metICFE-mdh (m)RNAs undergo RNase-mediated degradation in a process whose molecular details are poorly understood. Here we determined the secondary structure of the met leader RNA and found the element to harbor, beyond other conserved T-box riboswitch structural features, a terminator helix which is target for RNase III endoribonucleolytic cleavage. As the terminator is a thermodynamically highly stable structure, it also forms posttranscriptionally in met leader/ metICFE-mdh read-through transcripts. Cleavage by RNase III releases the met leader from metICFE-mdh mRNA and initiates RNase J-mediated degradation of the mRNA from the 5′-end. Of note, metICFE-mdh mRNA stability varies over the length of the transcript with a longer lifespan towards the 3′-end. The obtained data suggest that coordinated RNA decay represents another checkpoint in a complex regulatory network that adjusts costly methionine biosynthesis to current metabolic requirements.
Collapse
Affiliation(s)
- Freya D R Wencker
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany
| | - Gabriella Marincola
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany
| | - Sonja M K Schoenfelder
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany
| | - Sandra Maaß
- Institute of Microbiology, University of Greifswald, Greifswald 17489, Germany
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, Greifswald 17489, Germany
| | - Wilma Ziebuhr
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg 97080, Germany
| |
Collapse
|
19
|
Gao Y, Liu H, Zhang C, Su S, Chen Y, Chen X, Li Y, Shao Z, Zhang Y, Shao Q, Li J, Huang Z, Ma J, Gan J. Structural basis for guide RNA trimming by RNase D ribonuclease in Trypanosoma brucei. Nucleic Acids Res 2021; 49:568-583. [PMID: 33332555 PMCID: PMC7797062 DOI: 10.1093/nar/gkaa1197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 11/24/2020] [Indexed: 11/18/2022] Open
Abstract
Infection with kinetoplastid parasites, including Trypanosoma brucei (T. brucei), Trypanosoma cruzi (T. cruzi) and Leishmania can cause serious disease in humans. Like other kinetoplastid species, mRNAs of these disease-causing parasites must undergo posttranscriptional editing in order to be functional. mRNA editing is directed by gRNAs, a large group of small RNAs. Similar to mRNAs, gRNAs are also precisely regulated. In T. brucei, overexpression of RNase D ribonuclease (TbRND) leads to substantial reduction in the total gRNA population and subsequent inhibition of mRNA editing. However, the mechanisms regulating gRNA binding and cleavage by TbRND are not well defined. Here, we report a thorough structural study of TbRND. Besides Apo- and NMP-bound structures, we also solved one TbRND structure in complexed with single-stranded RNA. In combination with mutagenesis and in vitro cleavage assays, our structures indicated that TbRND follows the conserved two-cation-assisted mechanism in catalysis. TbRND is a unique RND member, as it contains a ZFD domain at its C-terminus. In addition to T. brucei, our studies also advanced our understanding on the potential gRNA degradation pathway in T. cruzi, Leishmania, as well for as other disease-associated parasites expressing ZFD-containing RNDs.
Collapse
Affiliation(s)
- Yanqing Gao
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Hehua Liu
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Chong Zhang
- College of Life Sciences, Sichuan University, Chengdu 610041, China
| | - Shichen Su
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yiqing Chen
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xi Chen
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yangyang Li
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Zhiwei Shao
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yixi Zhang
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Qiyuan Shao
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jixi Li
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Zhen Huang
- College of Life Sciences, Sichuan University, Chengdu 610041, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jianhua Gan
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| |
Collapse
|
20
|
Genetic Insight into the Domain Structure and Functions of Dicer-Type Ribonucleases. Int J Mol Sci 2021; 22:ijms22020616. [PMID: 33435485 PMCID: PMC7827160 DOI: 10.3390/ijms22020616] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/12/2022] Open
Abstract
Ribonuclease Dicer belongs to the family of RNase III endoribonucleases, the enzymes that specifically hydrolyze phosphodiester bonds found in double-stranded regions of RNAs. Dicer enzymes are mostly known for their essential role in the biogenesis of small regulatory RNAs. A typical Dicer-type RNase consists of a helicase domain, a domain of unknown function (DUF283), a PAZ (Piwi-Argonaute-Zwille) domain, two RNase III domains, and a double-stranded RNA binding domain; however, the domain composition of Dicers varies among species. Dicer and its homologues developed only in eukaryotes; nevertheless, the two enzymatic domains of Dicer, helicase and RNase III, display high sequence similarity to their prokaryotic orthologs. Evolutionary studies indicate that a combination of the helicase and RNase III domains in a single protein is a eukaryotic signature and is supposed to be one of the critical events that triggered the consolidation of the eukaryotic RNA interference. In this review, we provide the genetic insight into the domain organization and structure of Dicer proteins found in vertebrate and invertebrate animals, plants and fungi. We also discuss, in the context of the individual domains, domain deletion variants and partner proteins, a variety of Dicers’ functions not only related to small RNA biogenesis pathways.
Collapse
|
21
|
Arraes FBM, Martins-de-Sa D, Noriega Vasquez DD, Melo BP, Faheem M, de Macedo LLP, Morgante CV, Barbosa JARG, Togawa RC, Moreira VJV, Danchin EGJ, Grossi-de-Sa MF. Dissecting protein domain variability in the core RNA interference machinery of five insect orders. RNA Biol 2020; 18:1653-1681. [PMID: 33302789 DOI: 10.1080/15476286.2020.1861816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
RNA interference (RNAi)-mediated gene silencing can be used to control specific insect pest populations. Unfortunately, the variable efficiency in the knockdown levels of target genes has narrowed the applicability of this technology to a few species. Here, we examine the current state of knowledge regarding the miRNA (micro RNA) and siRNA (small interfering RNA) pathways in insects and investigate the structural variability at key protein domains of the RNAi machinery. Our goal was to correlate domain variability with mechanisms affecting the gene silencing efficiency. To this end, the protein domains of 168 insect species, encompassing the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera, were analysed using our pipeline, which takes advantage of meticulous structure-based sequence alignments. We used phylogenetic inference and the evolutionary rate coefficient (K) to outline the variability across domain regions and surfaces. Our results show that four domains, namely dsrm, Helicase, PAZ and Ribonuclease III, are the main contributors of protein variability in the RNAi machinery across different insect orders. We discuss the potential roles of these domains in regulating RNAi-mediated gene silencing and the role of loop regions in fine-tuning RNAi efficiency. Additionally, we identified several order-specific singularities which indicate that lepidopterans have evolved differently from other insect orders, possibly due to constant coevolution with plants and viruses. In conclusion, our results highlight several variability hotspots that deserve further investigation in order to improve the application of RNAi technology in the control of insect pests.
Collapse
Affiliation(s)
| | - Diogo Martins-de-Sa
- Departamento De Biologia Celular, Universidade De Brasília, Brasília-DF, Brazil
| | - Daniel D Noriega Vasquez
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Catholic University of Brasília, Brasília-DF, Brazil
| | - Bruno Paes Melo
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Viçosa University, UFV, Viçosa-MG, Brazil
| | - Muhammad Faheem
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Department of Biological Sciences, National University of Medical Sciences, Punjab, Pakistan
| | | | - Carolina Vianna Morgante
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Embrapa Semiarid, Petrolina-PE, Brazil.,National Institute of Science and Technology, Jakarta Embrapa-Brazil
| | | | - Roberto Coiti Togawa
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil
| | - Valdeir Junio Vaz Moreira
- Biotechnology Center, Brazil.,Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Departamento De Biologia Celular, Universidade De Brasília, Brasília-DF, Brazil
| | - Etienne G J Danchin
- National Institute of Science and Technology, Jakarta Embrapa-Brazil.,INRAE, Université Côte d'Azur, CNRS, Institut Sophia Agrobiotech, Sophia-Antipolis, France
| | - Maria Fatima Grossi-de-Sa
- Plant-Pest Molecular Interaction Laboratory (LIMPP), Brasilia, Brasília-DF, Brazil.,Catholic University of Brasília, Brasília-DF, Brazil.,National Institute of Science and Technology, Jakarta Embrapa-Brazil
| |
Collapse
|
22
|
Structures of B. subtilis Maturation RNases Captured on 50S Ribosome with Pre-rRNAs. Mol Cell 2020; 80:227-236.e5. [PMID: 32991829 DOI: 10.1016/j.molcel.2020.09.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 02/07/2023]
Abstract
The pathways for ribosomal RNA (rRNA) maturation diverge greatly among the domains of life. In the Gram-positive model bacterium, Bacillus subtilis, the final maturation steps of the two large ribosomal subunit (50S) rRNAs, 23S and 5S pre-rRNAs, are catalyzed by the double-strand specific ribonucleases (RNases) Mini-RNase III and RNase M5, respectively. Here we present a protocol that allowed us to solve the 3.0 and 3.1 Å resolution cryoelectron microscopy structures of these RNases poised to cleave their pre-rRNA substrates within the B. subtilis 50S particle. These data provide the first structural insights into rRNA maturation in bacteria by revealing how these RNases recognize and process double-stranded pre-rRNA. Our structures further uncover how specific ribosomal proteins act as chaperones to correctly fold the pre-rRNA substrates and, for Mini-III, anchor the RNase to the ribosome. These r-proteins thereby serve a quality-control function in the process from accurate ribosome assembly to rRNA processing.
Collapse
|
23
|
Thuy-Boun AS, Thomas JM, Grajo HL, Palumbo CM, Park S, Nguyen LT, Fisher AJ, Beal PA. Asymmetric dimerization of adenosine deaminase acting on RNA facilitates substrate recognition. Nucleic Acids Res 2020; 48:7958-7972. [PMID: 32597966 PMCID: PMC7641318 DOI: 10.1093/nar/gkaa532] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/09/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022] Open
Abstract
Adenosine deaminases acting on RNA (ADARs) are enzymes that convert adenosine to inosine in duplex RNA, a modification that exhibits a multitude of effects on RNA structure and function. Recent studies have identified ADAR1 as a potential cancer therapeutic target. ADARs are also important in the development of directed RNA editing therapeutics. A comprehensive understanding of the molecular mechanism of the ADAR reaction will advance efforts to develop ADAR inhibitors and new tools for directed RNA editing. Here we report the X-ray crystal structure of a fragment of human ADAR2 comprising its deaminase domain and double stranded RNA binding domain 2 (dsRBD2) bound to an RNA duplex as an asymmetric homodimer. We identified a highly conserved ADAR dimerization interface and validated the importance of these sequence elements on dimer formation via gel mobility shift assays and size exclusion chromatography. We also show that mutation in the dimerization interface inhibits editing in an RNA substrate-dependent manner for both ADAR1 and ADAR2.
Collapse
Affiliation(s)
| | - Justin M Thomas
- Department of Chemistry, University of California, Davis, CA, USA
| | - Herra L Grajo
- Department of Chemistry, University of California, Davis, CA, USA
| | - Cody M Palumbo
- Department of Chemistry, University of California, Davis, CA, USA
| | - SeHee Park
- Department of Chemistry, University of California, Davis, CA, USA
| | - Luan T Nguyen
- Department of Chemistry, University of California, Davis, CA, USA
| | - Andrew J Fisher
- Department of Chemistry, University of California, Davis, CA, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Peter A Beal
- Department of Chemistry, University of California, Davis, CA, USA
| |
Collapse
|
24
|
Tombusvirus p19 Captures RNase III-Cleaved Double-Stranded RNAs Formed by Overlapping Sense and Antisense Transcripts in Escherichia coli. mBio 2020; 11:mBio.00485-20. [PMID: 32518184 PMCID: PMC7373196 DOI: 10.1128/mbio.00485-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Antisense transcription is widespread in bacteria. By base pairing with overlapping sense RNAs, antisense RNAs (asRNA) can form double-stranded RNAs (dsRNA), which are cleaved by RNase III, a dsRNA endoribonuclease. The ectopic expression of plant Tombusvirus p19 in Escherichia coli stabilizes ∼21-nucleotide (nt) dsRNA RNase III decay intermediates, which enabled us to characterize otherwise highly unstable asRNA by deep sequencing of p19-captured dsRNA. RNase III-produced small dsRNA were formed at most bacterial genes in the bacterial genome and in a plasmid. Antisense transcription is widespread in bacteria. By base pairing with overlapping sense RNAs, antisense RNAs (asRNA) can form double-stranded RNAs (dsRNA), which are cleaved by RNase III, a dsRNA endoribonuclease. The ectopic expression of plant Tombusvirus p19 in Escherichia coli stabilizes ∼21-nucleotide (nt) dsRNA RNase III decay intermediates, which enabled us to characterize otherwise highly unstable asRNA by deep sequencing of p19-captured dsRNA. RNase III-produced small dsRNA were formed at most bacterial genes in the bacterial genome and in a plasmid. We classified the types of asRNA in genomic clusters producing the most abundant p19-captured dsRNA and confirmed RNase III regulation of asRNA and sense RNA decay at three type I toxin-antitoxin loci and at a coding gene, rsd. Furthermore, we provide potential evidence for the RNase III-dependent regulation of CspD protein by asRNA. The analysis of p19-captured dsRNA revealed an RNase III sequence preference for AU-rich sequences 3 nucleotides on either side of the cleavage sites and for GC-rich sequences in the 2-nt overhangs. Unexpectedly, GC-rich sequences were enriched in the middle section of p19-captured dsRNA, suggesting some unexpected sequence bias in p19 protein binding. Nonetheless, the ectopic expression of p19 is a sensitive method for identifying antisense transcripts and RNase III cleavage sites in dsRNA formed by overlapping sense and antisense transcripts in bacteria.
Collapse
|
25
|
A Mechanism for microRNA Arm Switching Regulated by Uridylation. Mol Cell 2020; 78:1224-1236.e5. [PMID: 32442398 DOI: 10.1016/j.molcel.2020.04.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/23/2020] [Accepted: 04/24/2020] [Indexed: 01/14/2023]
Abstract
Strand selection is a critical step in microRNA (miRNA) biogenesis. Although the dominant strand may change depending on cellular contexts, the molecular mechanism and physiological significance of such alternative strand selection (or "arm switching") remain elusive. Here we find miR-324 to be one of the strongly regulated miRNAs by arm switching and identify the terminal uridylyl transferases TUT4 and TUT7 to be the key regulators. Uridylation of pre-miR-324 by TUT4/7 re-positions DICER on the pre-miRNA and shifts the cleavage site. This alternative processing produces a duplex with a different terminus from which the 3' strand (3p) is selected instead of the 5' strand (5p). In glioblastoma, the TUT4/7 and 3p levels are upregulated, whereas the 5p level is reduced. Manipulation of the strand ratio is sufficient to impair glioblastoma cell proliferation. This study uncovers a role of uridylation as a molecular switch in alternative strand selection and implicates its therapeutic potential.
Collapse
|
26
|
Jin W, Wang J, Liu CP, Wang HW, Xu RM. Structural Basis for pri-miRNA Recognition by Drosha. Mol Cell 2020; 78:423-433.e5. [DOI: 10.1016/j.molcel.2020.02.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/13/2020] [Accepted: 02/27/2020] [Indexed: 12/22/2022]
|
27
|
Yadav DK, Zigáčková D, Zlobina M, Klumpler T, Beaumont C, Kubíčková M, Vaňáčová Š, Lukavsky PJ. Staufen1 reads out structure and sequence features in ARF1 dsRNA for target recognition. Nucleic Acids Res 2020; 48:2091-2106. [PMID: 31875226 PMCID: PMC7038937 DOI: 10.1093/nar/gkz1163] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 12/13/2022] Open
Abstract
Staufen1 (STAU1) is a dsRNA binding protein mediating mRNA transport and localization, translational control and STAU1-mediated mRNA decay (SMD). The STAU1 binding site (SBS) within human ADP-ribosylation factor1 (ARF1) 3′UTR binds STAU1 and this downregulates ARF1 cytoplasmic mRNA levels by SMD. However, how STAU1 recognizes specific mRNA targets is still under debate. Our structure of the ARF1 SBS–STAU1 complex uncovers target recognition by STAU1. STAU1 dsRNA binding domain (dsRBD) 4 interacts with two pyrimidines and one purine from the minor groove side via helix α1, the β1–β2 loop anchors the dsRBD at the end of the dsRNA and lysines in helix α2 bind to the phosphodiester backbone from the major groove side. STAU1 dsRBD3 displays the same binding mode with specific recognition of one guanine base. Mutants disrupting minor groove recognition of ARF1 SBS affect in vitro binding and reduce SMD in vivo. Our data thus reveal how STAU1 recognizes minor groove features in dsRNA relevant for target selection.
Collapse
Affiliation(s)
- Deepak Kumar Yadav
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Dagmar Zigáčková
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Maria Zlobina
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Tomáš Klumpler
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Christelle Beaumont
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Monika Kubíčková
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Štěpánka Vaňáčová
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Peter J Lukavsky
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| |
Collapse
|
28
|
Nguyen TL, Nguyen TD, Bao S, Li S, Nguyen TA. The internal loops in the lower stem of primary microRNA transcripts facilitate single cleavage of human Microprocessor. Nucleic Acids Res 2020; 48:2579-2593. [PMID: 31956890 PMCID: PMC7049713 DOI: 10.1093/nar/gkaa018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 12/23/2022] Open
Abstract
The human Microprocessor complex cleaves primary microRNA (miRNA) transcripts (pri-miRNAs) to initiate miRNA synthesis. Microprocessor consists of DROSHA (an RNase III enzyme), and DGCR8. DROSHA contains two RNase III domains, RIIIDa and RIIIDb, which simultaneously cleave the 3p- and 5p-strands of pri-miRNAs, respectively. In this study, we show that the internal loop located in the lower stem of numerous pri-miRNAs selectively inhibits the cleavage of Microprocessor on their 3p-strand, thereby, facilitating the single cleavage on their 5p-strand. This single cleavage does not lead to the production of miRNA but instead, it downregulates miRNA expression. We also demonstrate that by manipulating the size of the internal loop in the lower stem of pri-miRNAs, we can alter the ratio of single-cut to double-cut products resulted from the catalysis of Microprocessor, thus changing miRNA production in the in vitro pri-miRNA processing assays and in human cells. Therefore, the oscillating level of the single cleavage suggests another way of regulation of miRNA expression and offers an alternative approach to miRNA knockdown.
Collapse
Affiliation(s)
- Thuy Linh Nguyen
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Trung Duc Nguyen
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Sheng Bao
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Shaohua Li
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Tuan Anh Nguyen
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| |
Collapse
|
29
|
Wright CB, Uehara H, Kim Y, Yasuma T, Yasuma R, Hirahara S, Makin RD, Apicella I, Pereira F, Nagasaka Y, Narendran S, Fukuda S, Albuquerque R, Fowler BJ, Bastos-Carvalho A, Georgel P, Hatada I, Chang B, Kerur N, Ambati BK, Ambati J, Gelfand BD. Chronic Dicer1 deficiency promotes atrophic and neovascular outer retinal pathologies in mice. Proc Natl Acad Sci U S A 2020; 117:2579-2587. [PMID: 31964819 PMCID: PMC7007521 DOI: 10.1073/pnas.1909761117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Degeneration of the retinal pigmented epithelium (RPE) and aberrant blood vessel growth in the eye are advanced-stage processes in blinding diseases such as age-related macular degeneration (AMD), which affect hundreds of millions of people worldwide. Loss of the RNase DICER1, an essential factor in micro-RNA biogenesis, is implicated in RPE atrophy. However, the functional implications of DICER1 loss in choroidal and retinal neovascularization are unknown. Here, we report that two independent hypomorphic mouse strains, as well as a separate model of postnatal RPE-specific DICER1 ablation, all presented with spontaneous RPE degeneration and choroidal and retinal neovascularization. DICER1 hypomorphic mice lacking critical inflammasome components or the innate immune adaptor MyD88 developed less severe RPE atrophy and pathological neovascularization. DICER1 abundance was also reduced in retinas of the JR5558 mouse model of spontaneous choroidal neovascularization. Finally, adenoassociated vector-mediated gene delivery of a truncated DICER1 variant (OptiDicer) reduced spontaneous choroidal neovascularization in JR5558 mice. Collectively, these findings significantly expand the repertoire of DICER1 in preserving retinal homeostasis by preventing both RPE degeneration and pathological neovascularization.
Collapse
Affiliation(s)
- Charles B Wright
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40506
| | - Hironori Uehara
- Department of Ophthalmology, Loma Linda University, Loma Linda, CA 92350
| | - Younghee Kim
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Tetsuhiro Yasuma
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40506
| | - Reo Yasuma
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Shuichiro Hirahara
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Ryan D Makin
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Molecular and Cellular Basis of Disease Graduate Program, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Ivana Apicella
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Felipe Pereira
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Yosuke Nagasaka
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Siddharth Narendran
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Aravind Medical Research Foundation, Aravind Eye Care System, Madurai, Tamil Nadu 625020, India
| | - Shinichi Fukuda
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Romulo Albuquerque
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40506
| | - Benjamin J Fowler
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40506
| | - Ana Bastos-Carvalho
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40506
| | - Philippe Georgel
- Laboratoire d'ImmunoRhumatologie Moléculaire, INSERM UMR-S1109, LabEx Transplantex, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, 67085 Strasbourg, France
- Fédération Hospitalo-Universitaire OMICARE, Université de Strasbourg, 67085 Strasbourg, France
| | - Izuho Hatada
- Laboratory of Genome Science, Biosignal Genome Resource Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609
| | - Nagaraj Kerur
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | | | - Jayakrishna Ambati
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22903
| | - Bradley D Gelfand
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA 22903;
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22903
- Department of Biomedical Engineering, University of Virginia School of Engineering, Charlottesville, VA 22904
| |
Collapse
|
30
|
Asgari M, Ilbeigikhamsehnejad M, Rismani E, Dinparast Djadid N, Raz A. Molecular characterization of RNase III protein of Asaia sp. for developing a robust RNAi-based paratransgensis tool to affect the sexual life-cycle of Plasmodium or Anopheles fitness. Parasit Vectors 2020; 13:42. [PMID: 31996254 PMCID: PMC6990573 DOI: 10.1186/s13071-020-3889-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 01/04/2020] [Indexed: 01/02/2023] Open
Abstract
Background According to scientific recommendations, paratransgenesis is one of the solutions for improving the effectiveness of the Global Malaria Eradication Programme. In paratransgenesis, symbiont microorganisms are used for distorting or blocking the parasite life-cycle, affecting the fitness and longevity of vectors or reducing the vectorial competence. It has been revealed recently that bacteria could be used as potent tools for double stranded RNA production and delivery to insects. Moreover, findings showed that RNase III mutant bacteria are more competent for this aim. Asaia spp. have been introduced as potent paratransgenesis candidates for combating malaria and, based on their specific features for this goal, could be considered as effective dsRNA production and delivery tools to Anopheles spp. Therefore, we decided to characterize the rnc gene and its related protein to provide the basic required information for creating an RNase III mutant Asaia bacterium. Methods Asaia bacteria were isolated from field-collected Anopheles stephensi mosquitoes. The rnc gene and its surrounding sequences were characterized by rapid amplification of genomic ends. RNase III recombinant protein was expressed in E. coli BL21 and biological activity of the purified recombinant protein was assayed. Furthermore, Asaia RNaseIII amino acid sequence was analyzed by in silico approaches such as homology modeling and docking to determine its structural properties. Results In this study, the structure of rnc gene and its related operon from Asaia sp. was determined. In addition, by performing superimposition and docking with specific substrate, the structural features of Asaia RNaseIII protein such as critical residues which are involved and essential for proper folding of active site, binding of magnesium ions and double stranded RNA molecule to protein and cleaving of dsRNA molecules, were determined. Conclusions In this study, the basic and essential data for creating an RNase III mutant Asaia sp. strain, which is the first step of developing an efficient RNAi-based paratransgenesis tool, were acquired. Asaia sp. have been found in different medically-important vectors and these data are potentially very helpful for researchers studying paratransgenesis and vector-borne diseases and are interested in applying the RNAi technology in the field.
Collapse
Affiliation(s)
- Majid Asgari
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Mahdokht Ilbeigikhamsehnejad
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Elham Rismani
- Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran
| | - Navid Dinparast Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Abbasali Raz
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| |
Collapse
|
31
|
Jin L, Song H, Tropea JE, Needle D, Waugh DS, Gu S, Ji X. The molecular mechanism of dsRNA processing by a bacterial Dicer. Nucleic Acids Res 2019; 47:4707-4720. [PMID: 30916338 DOI: 10.1093/nar/gkz208] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/01/2019] [Accepted: 03/17/2019] [Indexed: 01/21/2023] Open
Abstract
Members of the ribonuclease (RNase) III family regulate gene expression by processing dsRNAs. It was previously shown that Escherichia coli (Ec) RNase III recognizes dsRNA with little sequence specificity and the cleavage products are mainly 11 nucleotides (nt) long. It was also shown that the mutation of a glutamate (EcE38) to an alanine promotes generation of siRNA-like products typically 22 nt long. To fully characterize substrate specificity and product size of RNase IIIs, we performed in vitro cleavage of dsRNAs by Ec and Aquifex aeolicus (Aa) enzymes and delineated their products by next-generation sequencing. Surprisingly, we found that both enzymes cleave dsRNA at preferred sites, among which a guanine nucleotide was enriched at a specific position (+3G). Based on sequence and structure analyses, we conclude that RNase IIIs recognize +3G via a conserved glutamine (EcQ165/AaQ161) side chain. Abolishing this interaction by mutating the glutamine to an alanine eliminates the observed +3G preference. Furthermore, we identified a second glutamate (EcE65/AaE64), which, when mutated to alanine, also enhances the production of siRNA-like products. Based on these findings, we created a bacterial Dicer that is ideally suited for producing heterogeneous siRNA cocktails to be used in gene silencing studies.
Collapse
Affiliation(s)
- Lan Jin
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - He Song
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Joseph E Tropea
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Danielle Needle
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - David S Waugh
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Shuo Gu
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Xinhua Ji
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| |
Collapse
|
32
|
Study of the role of Mg 2+ in dsRNA processing mechanism by bacterial RNase III through QM/MM simulations. J Biol Inorg Chem 2019; 25:89-98. [PMID: 31754801 DOI: 10.1007/s00775-019-01741-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 11/06/2019] [Indexed: 12/28/2022]
Abstract
The ribonuclease III (RNase III) cleaves dsRNA in specific positions generating mature RNAs. RNase III enzymes play important roles in RNA processing, post-transcriptional gene expression, and defense against viral infection. The enzyme's active site contains Mg2+ ions bound by a network of acidic residues and water molecules, but there is a lack of information about their specific roles. In this work, multiple steered molecular dynamics simulations at QM/MM level were performed to explore the hydrolysis reaction carried out by the enzyme. Free energy profiles modifying the features of the active site are obtained and the role of Mg2+ ions, the solvent molecules and the residues of the active site are discussed in detail. Our results show that Mg2+ ions carry out different roles in the hydrolysis process positioning the substrate for the attack from a coordinated nucleophile and activating it to perform hydrolysis reaction, cleaving the dsRNA backbone in a SN2 substitution. In addition, water molecules present in the active site lower the energy barrier of the process. RNase III hydrolyzes dsRNA to generate mature RNAs. For this purpose, its active site contains Mg2+ which has an important role during the reaction. Results show that the Mg2+ activates the solvent molecule that produces the nucleophilic attack and the surrounding waters contribute significantly to the hydrolysis process.
Collapse
|
33
|
A deep learning framework to predict binding preference of RNA constituents on protein surface. Nat Commun 2019; 10:4941. [PMID: 31666519 PMCID: PMC6821705 DOI: 10.1038/s41467-019-12920-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/08/2019] [Indexed: 12/21/2022] Open
Abstract
Protein-RNA interaction plays important roles in post-transcriptional regulation. However, the task of predicting these interactions given a protein structure is difficult. Here we show that, by leveraging a deep learning model NucleicNet, attributes such as binding preference of RNA backbone constituents and different bases can be predicted from local physicochemical characteristics of protein structure surface. On a diverse set of challenging RNA-binding proteins, including Fem-3-binding-factor 2, Argonaute 2 and Ribonuclease III, NucleicNet can accurately recover interaction modes discovered by structural biology experiments. Furthermore, we show that, without seeing any in vitro or in vivo assay data, NucleicNet can still achieve consistency with experiments, including RNAcompete, Immunoprecipitation Assay, and siRNA Knockdown Benchmark. NucleicNet can thus serve to provide quantitative fitness of RNA sequences for given binding pockets or to predict potential binding pockets and binding RNAs for previously unknown RNA binding proteins.
Collapse
|
34
|
Bou-Nader C, Barraud P, Pecqueur L, Pérez J, Velours C, Shepard W, Fontecave M, Tisné C, Hamdane D. Molecular basis for transfer RNA recognition by the double-stranded RNA-binding domain of human dihydrouridine synthase 2. Nucleic Acids Res 2019; 47:3117-3126. [PMID: 30605527 PMCID: PMC6451096 DOI: 10.1093/nar/gky1302] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/12/2018] [Accepted: 12/29/2018] [Indexed: 11/17/2022] Open
Abstract
Double stranded RNA-binding domain (dsRBD) is a ubiquitous domain specialized in the recognition of double-stranded RNAs (dsRNAs). Present in many proteins and enzymes involved in various functional roles of RNA metabolism, including RNA splicing, editing, and transport, dsRBD generally binds to RNAs that lack complex structures. However, this belief has recently been challenged by the discovery of a dsRBD serving as a major tRNA binding module for human dihydrouridine synthase 2 (hDus2), a flavoenzyme that catalyzes synthesis of dihydrouridine within the complex elbow structure of tRNA. We here unveil the molecular mechanism by which hDus2 dsRBD recognizes a tRNA ligand. By solving the crystal structure of this dsRBD in complex with a dsRNA together with extensive characterizations of its interaction with tRNA using mutagenesis, NMR and SAXS, we establish that while hDus2 dsRBD retains a conventional dsRNA recognition capability, the presence of an N-terminal extension appended to the canonical domain provides additional residues for binding tRNA in a structure-specific mode of action. Our results support that this extension represents a feature by which the dsRBD specializes in tRNA biology and more broadly highlight the importance of structural appendages to canonical domains in promoting the emergence of functional diversity.
Collapse
Affiliation(s)
- Charles Bou-Nader
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Pierre Barraud
- Institut de biologie physico-chimique (IBPC), CNRS, UMR 8261 CNRS/Université Paris Diderot, 13 rue Pierre et Marie Curie, Paris 75005, France.,Laboratoire de cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ludovic Pecqueur
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Javier Pérez
- Synchrotron Soleil, L'Orme des Merisiers, BP 48, 91192 Gif sur Yvette Cedex, France
| | - Christophe Velours
- Macromolecular interaction platform of I2BC, UMR9198, Centre de Recherche de Gif-sur-Yvette, France
| | - William Shepard
- Synchrotron Soleil, L'Orme des Merisiers, BP 48, 91192 Gif sur Yvette Cedex, France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Carine Tisné
- Institut de biologie physico-chimique (IBPC), CNRS, UMR 8261 CNRS/Université Paris Diderot, 13 rue Pierre et Marie Curie, Paris 75005, France.,Laboratoire de cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Djemel Hamdane
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| |
Collapse
|
35
|
Si Y, Wang X, Yang G, Yang T, Li Y, Ayala GJ, Li X, Wang H, Su J. Crystal Structures of Pyrophosphatase from Acinetobacter baumannii: Snapshots of Pyrophosphate Binding and Identification of a Phosphorylated Enzyme Intermediate. Int J Mol Sci 2019; 20:ijms20184394. [PMID: 31500178 PMCID: PMC6770254 DOI: 10.3390/ijms20184394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 08/31/2019] [Accepted: 09/03/2019] [Indexed: 11/26/2022] Open
Abstract
All living things have pyrophosphatases that hydrolyze pyrophosphate and release energy. This energetically favorable reaction drives many energetically unfavorable reactions. An accepted catalytic model of pyrophosphatase shows that a water molecule activated by two divalent cations (M1 and M2) within the catalytic center can attack pyrophosphate in an SN2 mechanism and thus hydrolyze the molecule. However, our co-crystal structure of Acinetobacter baumannii pyrophosphatase with pyrophosphate shows that a water molecule from the solvent may, in fact, be the actual catalytic water. In the co-crystal structure of the wild-type pyrophosphatase with pyrophosphate, the electron density of the catalytic centers of each monomer are different from one another. This indicates that pyrophosphates in the catalytic center are dynamic. Our mass spectroscopy results have identified a highly conserved lysine residue (Lys30) in the catalytic center that is phosphorylated, indicating that the enzyme could form a phosphoryl enzyme intermediate during hydrolysis. Mutation of Lys30 to Arg abolished the activity of the enzyme. In the structure of the apo wild type enzyme, we observed that a Na+ ion is coordinated by residues within a loop proximal to the catalytic center. Therefore, we mutated three key residues within the loop (K143R, P147G, and K149R) and determined Na+ and K+-induced inhibition on their activities. Compared to the wild type enzyme, P147G is most sensitive to these cations, whereas K143R was inactive and K149R showed no change in activity. These data indicate that monovalent cations could play a role in down-regulating pyrophosphatase activity in vivo. Overall, our results reveal new aspects of pyrophosphatase catalysis and could assist in the design of specific inhibitors of Acinetobacter baumannii growth.
Collapse
Affiliation(s)
- Yunlong Si
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xing Wang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Guosong Yang
- Zhongke Biopharm Co., LTD, East of Beijing, Beijing 101601, China
| | - Tong Yang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Yuying Li
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Gabriela Jaramillo Ayala
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xumin Li
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Hao Wang
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Jiyong Su
- Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
| |
Collapse
|
36
|
Yang C, Wu R, Liu H, Chen Y, Gao Y, Chen X, Li Y, Ma J, Li J, Gan J. Structural insights into DNA degradation by human mitochondrial nuclease MGME1. Nucleic Acids Res 2019; 46:11075-11088. [PMID: 30247721 PMCID: PMC6237815 DOI: 10.1093/nar/gky855] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 09/11/2018] [Indexed: 01/16/2023] Open
Abstract
Mitochondrial nucleases play important roles in accurate maintenance and correct metabolism of mtDNA, the own genetic materials of mitochondria that are passed exclusively from mother to child. MGME1 is a highly conserved DNase that was discovered recently. Mutations in MGME1-coding gene lead to severe mitochondrial syndromes characterized by external ophthalmoplegia, emaciation, and respiratory failure in humans. Unlike many other nucleases that are distributed in multiple cellular organelles, human MGME1 is a mitochondria-specific nuclease; therefore, it can serve as an ideal target for treating related syndromes. Here, we report one HsMGME1-Mn2+ complex and three different HsMGME1-DNA complex structures. In combination with in vitro cleavage assays, our structures reveal the detailed molecular basis for substrate DNA binding and/or unwinding by HsMGME1. Besides the conserved two-cation-assisted catalytic mechanism, structural analysis of HsMGME1 and comparison with homologous proteins also clarified substrate binding and cleavage directionalities of the DNA double-strand break repair complexes RecBCD and AddAB.
Collapse
Affiliation(s)
- Chun Yang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Ruiqi Wu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Hehua Liu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China.,State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yiqing Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yanqing Gao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xi Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yangyang Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jixi Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China.,Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jianhua Gan
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| |
Collapse
|
37
|
Oroz J, Laurents DV. RNA binding proteins: Diversity from microsurgeons to cowboys. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194398. [PMID: 31271896 DOI: 10.1016/j.bbagrm.2019.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/03/2019] [Accepted: 06/13/2019] [Indexed: 01/21/2023]
Abstract
The conformation and mechanism of proteins that degrade and bind RNA, which has provided key insights into post-transcriptional gene regulation, is explored here. During the twentieth century's last decades, the characterization of ribonucleases and RNA binding domains revealed the diversity of their reaction mechanisms and modes of RNA recognition, and the bases of protein folding, substrate specificity and binding affinity. More recent research showed how these domains combine through oligomerization or genetic recombination to create larger proteins with highly specific and readily programmable ribonucleolytic activity. In the last 15 years, the study of the capacity of proteins, usually disordered, to pool RNAs into discrete, non-aqueous microdroplets to facilitate their transport, modification and degradation - analogous to cowboys herding cattle - has advanced our comprehension of gene expression. Finally, the current uses of RNA binding proteins and the future applications of protein/RNA microdroplets are highlighted.
Collapse
Affiliation(s)
- Javier Oroz
- "Rocasolano" Institute of Physical Chemistry, Spanish National Research Council, Serrano 119, Madrid 28006, Spain
| | - Douglas V Laurents
- "Rocasolano" Institute of Physical Chemistry, Spanish National Research Council, Serrano 119, Madrid 28006, Spain.
| |
Collapse
|
38
|
Altuvia Y, Bar A, Reiss N, Karavani E, Argaman L, Margalit H. In vivo cleavage rules and target repertoire of RNase III in Escherichia coli. Nucleic Acids Res 2019; 46:10380-10394. [PMID: 30113670 PMCID: PMC6212723 DOI: 10.1093/nar/gky684] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/18/2018] [Indexed: 12/02/2022] Open
Abstract
Bacterial RNase III plays important roles in the processing and degradation of RNA transcripts. A major goal is to identify the cleavage targets of this endoribonuclease at a transcriptome-wide scale and delineate its in vivo cleavage rules. Here we applied to Escherichia coli grown to either exponential or stationary phase a tailored RNA-seq-based technology, which allows transcriptome-wide mapping of RNase III cleavage sites at a nucleotide resolution. Our analysis of the large-scale in vivo cleavage data substantiated the established cleavage pattern of a double cleavage in an intra-molecular stem structure, leaving 2-nt-long 3′ overhangs, and refined the base-pairing preferences in the cleavage site vicinity. Intriguingly, we observed that the two stem positions between the cleavage sites are highly base-paired, usually involving at least one G-C or C-G base pair. We present a clear distinction between intra-molecular stem structures that are RNase III substrates and intra-molecular stem structures randomly selected across the transcriptome, emphasizing the in vivo specificity of RNase III. Our study provides a comprehensive map of the cleavage sites in both intra-molecular and inter-molecular duplex substrates, providing novel insights into the involvement of RNase III in post-transcriptional regulation in the bacterial cell.
Collapse
Affiliation(s)
- Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Amir Bar
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Niv Reiss
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ehud Karavani
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Liron Argaman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| |
Collapse
|
39
|
Vechetti IJ, Wen Y, Chaillou T, Murach KA, Alimov AP, Figueiredo VC, Dal-Pai-Silva M, McCarthy JJ. Life-long reduction in myomiR expression does not adversely affect skeletal muscle morphology. Sci Rep 2019; 9:5483. [PMID: 30940834 PMCID: PMC6445125 DOI: 10.1038/s41598-019-41476-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 03/11/2019] [Indexed: 12/20/2022] Open
Abstract
We generated an inducible, skeletal muscle-specific Dicer knockout mouse to deplete microRNAs in adult skeletal muscle. Following tamoxifen treatment, Dicer mRNA expression was significantly decreased by 87%. Wild-type (WT) and Dicer knockout (KO) mice were subjected to either synergist ablation or hind limb suspension for two weeks. There was no difference in muscle weight with hypertrophy or atrophy between WT and KO groups; however, even with the significant loss of Dicer expression, myomiR (miR-1, -133a and -206) expression was only reduced by 38% on average. We next aged WT and KO mice for ~22 months following Dicer inactivation to determine if myomiR expression would be further reduced over a prolonged timeframe and assess the effects of myomiR depletion on skeletal muscle phenotype. Skeletal muscle Dicer mRNA expression remained significantly decreased by 80% in old KO mice and sequencing of cloned Dicer mRNA revealed the complete absence of the floxed exons in KO skeletal muscle. Despite a further reduction of myomiR expression to ~50% of WT, no change was observed in muscle morphology between WT and KO groups. These results indicate the life-long reduction in myomiR levels did not adversely affect skeletal muscle phenotype and suggest the possibility that microRNA expression is uniquely regulated in skeletal muscle.
Collapse
Affiliation(s)
- Ivan J Vechetti
- Department of Physiology, College of Medicine, University of Kentucky, Kentucky, USA
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA
- Department of Morphology, São Paulo State University, Institute of Biosciences, Botucatu, Brazil
| | - Yuan Wen
- Department of Physiology, College of Medicine, University of Kentucky, Kentucky, USA
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA
| | - Thomas Chaillou
- Örebro University, School of Health Sciences, Örebro, Sweden
| | - Kevin A Murach
- Department of Rehabilitation Sciences, College of Health Sciences, Kentucky, USA
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA
| | - Alexander P Alimov
- Department of Physiology, College of Medicine, University of Kentucky, Kentucky, USA
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA
| | - Vandre C Figueiredo
- Department of Physiology, College of Medicine, University of Kentucky, Kentucky, USA
- Department of Rehabilitation Sciences, College of Health Sciences, Kentucky, USA
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA
| | - Maeli Dal-Pai-Silva
- Department of Morphology, São Paulo State University, Institute of Biosciences, Botucatu, Brazil
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Kentucky, USA.
- Center for Muscle Biology University of Kentucky, Lexington, Kentucky, USA.
| |
Collapse
|
40
|
Kwon SC, Baek SC, Choi YG, Yang J, Lee YS, Woo JS, Kim VN. Molecular Basis for the Single-Nucleotide Precision of Primary microRNA Processing. Mol Cell 2019; 73:505-518.e5. [DOI: 10.1016/j.molcel.2018.11.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/11/2018] [Accepted: 11/01/2018] [Indexed: 12/16/2022]
|
41
|
Bofill-De Ros X, Kasprzak WK, Bhandari Y, Fan L, Cavanaugh Q, Jiang M, Dai L, Yang A, Shao TJ, Shapiro BA, Wang YX, Gu S. Structural Differences between Pri-miRNA Paralogs Promote Alternative Drosha Cleavage and Expand Target Repertoires. Cell Rep 2019; 26:447-459.e4. [PMID: 30625327 PMCID: PMC6369706 DOI: 10.1016/j.celrep.2018.12.054] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 11/11/2018] [Accepted: 12/11/2018] [Indexed: 12/16/2022] Open
Abstract
MicroRNA (miRNA) processing begins with Drosha cleavage, the fidelity of which is critical for downstream processing and mature miRNA target specificity. To understand how pri-miRNA sequence and structure influence Drosha cleavage, we studied the maturation of three pri-miR-9 paralogs, which encode the same mature miRNA but differ in the surrounding scaffold. We show that pri-miR-9-1 has a unique Drosha cleavage profile due to its distorted and flexible stem structure. Cleavage of pri-miR-9-1, but not pri-miR-9-2 or pri-miR-9-3, generates an alternative miR-9 with a shifted seed sequence that expands the scope of its target RNAs. Analyses of low-grade glioma patient samples indicate that the alternative-miR-9 has a potential role in tumor progression. Furthermore, we provide evidence that distortion of pri-miRNA stems induced by asymmetric internal loops correlates with Drosha cleavage at non-canonical sites. Our studies reveal that pri-miRNA paralogs can have distinct functions via differential Drosha processing.
Collapse
Affiliation(s)
- Xavier Bofill-De Ros
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Wojciech K Kasprzak
- Basic Science Program, RNA Biology Laboratory, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, MD 21702, USA
| | - Yuba Bhandari
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Lixin Fan
- Small-Angle X-ray Scattering Core Facility, Center for Cancer Research of the National Cancer Institute, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - Quinn Cavanaugh
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Minjie Jiang
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Lisheng Dai
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Acong Yang
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Tie-Juan Shao
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; School of Basic Medicine, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Bruce A Shapiro
- RNA Structure and Design Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Yun-Xing Wang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Shuo Gu
- RNA Mediated Gene Regulation Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| |
Collapse
|
42
|
Abou Elela S, Ji X. Structure and function of Rnt1p: An alternative to RNAi for targeted RNA degradation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 10:e1521. [PMID: 30548404 DOI: 10.1002/wrna.1521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/30/2018] [Accepted: 11/15/2018] [Indexed: 12/27/2022]
Abstract
The double-stranded RNA-binding protein (dsRBP) family controls RNA editing, stability, and function in all eukaryotes. The central feature of this family is the recognition of a generic RNA duplex using highly conserved double-stranded RNA-binding domain (dsRBD) that recognizes the characteristic distance between the minor grooves created by the RNA helix. Variations on this theme that confer species and functional specificities have been reported but most dsRBPs retain their capacity to bind generic dsRNA. The ribonuclease III (RNase III) family members fall into four classes, represented by bacterial RNase III, yeast Rnt1p, human Drosha, and human Dicer, respectively. Like all dsRBPs and most members of the RNase III family, Rnt1p has a dsRBD, but unlike most of its kin, it poorly binds to generic RNA helices. Instead, Rnt1p, the only known RNase III expressed in Saccharomyces cerevisiae that lacks the RNAi (RNA interference) machinery, recognizes a specific class of stem-loop structures. To recognize the specific substrates, the dsRBD of Rnt1p is specialized, featuring a αβββααα topology and a sequence-specific RNA-binding motif at the C-terminus. Since the discovery of Rnt1p in 1996, significant progress has been made in studies of its genetics, function, structure, and mechanism of action, explaining the reasons and mechanisms for the increased specificity of this enzyme and its impact on the mechanism of RNA degradation. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Processing > Processing of Small RNAs RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
Collapse
Affiliation(s)
- Sherif Abou Elela
- Microbiology and Infectiology Department, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Xinhua Ji
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, Maryland
| |
Collapse
|
43
|
Lazzaretti D, Bandholz-Cajamarca L, Emmerich C, Schaaf K, Basquin C, Irion U, Bono F. The crystal structure of Staufen1 in complex with a physiological RNA sheds light on substrate selectivity. Life Sci Alliance 2018; 1:e201800187. [PMID: 30456389 PMCID: PMC6238398 DOI: 10.26508/lsa.201800187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 01/29/2023] Open
Abstract
Combination of in vitro and in vivo data show that RNA sequence influences Staufen target recognition and that protein–RNA base contacts are required for Staufen function in Drosophila. During mRNA localization, RNA-binding proteins interact with specific structured mRNA localization motifs. Although several such motifs have been identified, we have limited structural information on how these interact with RNA-binding proteins. Staufen proteins bind structured mRNA motifs through dsRNA-binding domains (dsRBD) and are involved in mRNA localization in Drosophila and mammals. We solved the structure of two dsRBDs of human Staufen1 in complex with a physiological dsRNA sequence. We identified interactions between the dsRBDs and the RNA sugar–phosphate backbone and direct contacts of conserved Staufen residues to RNA bases. Mutating residues mediating nonspecific backbone interactions only affected Staufen function in Drosophila when in vitro binding was severely reduced. Conversely, residues involved in base-directed interactions were required in vivo even when they minimally affected in vitro binding. Our work revealed that Staufen can read sequence features in the minor groove of dsRNA and suggests that these influence target selection in vivo.
Collapse
Affiliation(s)
| | | | | | - Kristina Schaaf
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Claire Basquin
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Uwe Irion
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Fulvia Bono
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, UK
| |
Collapse
|
44
|
Dzananovic E, McKenna SA, Patel TR. Viral proteins targeting host protein kinase R to evade an innate immune response: a mini review. Biotechnol Genet Eng Rev 2018; 34:33-59. [PMID: 29716441 DOI: 10.1080/02648725.2018.1467151] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The innate immune system offers a first line of defense by neutralizing foreign pathogens such as bacteria, fungi, and viruses. These pathogens express molecules (RNA and proteins) that have discrete structures, known as the pathogen-associated molecular patterns that are recognized by a highly specialized class of host proteins called pattern recognition receptors to facilitate the host's immune response against infection. The RNA-dependent Protein Kinase R (PKR) is one of the host's pattern recognition receptors that is a key component of an innate immune system. PKR recognizes imperfectly double-stranded non-coding viral RNA molecules via its N-terminal double-stranded RNA binding motifs, undergoes phosphorylation of the C-terminal kinase domain, ultimately resulting in inhibition of viral protein translation by inhibiting the guanine nucleotide exchange activity of eukaryotic initiation factor 2α. Not surprisingly, viruses have evolved mechanisms by which viral non-coding RNA or protein molecules inhibit PKR's activation and/or its downstream activity to allow viral replication. In this review, we will highlight the role of viral proteins in inhibiting PKR's activity and summarize currently known mechanisms by which viral proteins execute such inhibitory activity.
Collapse
Affiliation(s)
- Edis Dzananovic
- a Plant Pathology, Plant Protection and Molecular Biology , Agriculture and Agri-Food Canada , Saskatoon , Canada
| | - Sean A McKenna
- b Department of Chemistry, Manitoba Institute for Materials, Department of Biochemistry and Medical Genetics , University of Manitoba , Winnipeg , Canada
| | - Trushar R Patel
- c Department of Chemistry and Biochemistry , Alberta RNA Research and Training Institute, University of Lethbridge , Lethbridge , Canada.,d DiscoveryLab, Faculty of Medicine & Dentistry , University of Alberta , Edmonton , Canada.,e Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine , University of Calgary , Calgary , Canada
| |
Collapse
|
45
|
Liu Z, Wang J, Cheng H, Ke X, Sun L, Zhang QC, Wang HW. Cryo-EM Structure of Human Dicer and Its Complexes with a Pre-miRNA Substrate. Cell 2018; 173:1191-1203.e12. [PMID: 29706542 DOI: 10.1016/j.cell.2018.03.080] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 01/02/2018] [Accepted: 03/28/2018] [Indexed: 12/26/2022]
Abstract
Human Dicer (hDicer) is a multi-domain protein belonging to the RNase III family. It plays pivotal roles in small RNA biogenesis during the RNA interference (RNAi) pathway by processing a diverse range of double-stranded RNA (dsRNA) precursors to generate ∼22 nt microRNA (miRNA) or small interfering RNA (siRNA) products for sequence-directed gene silencing. In this work, we solved the cryoelectron microscopy (cryo-EM) structure of hDicer in complex with its cofactor protein TRBP and revealed the precise spatial arrangement of hDicer's multiple domains. We further solved structures of the hDicer-TRBP complex bound with pre-let-7 RNA in two distinct conformations. In combination with biochemical analysis, these structures reveal a property of the hDicer-TRBP complex to promote the stability of pre-miRNA's stem duplex in a pre-dicing state. These results provide insights into the mechanism of RNA processing by hDicer and illustrate the regulatory role of hDicer's N-terminal helicase domain.
Collapse
Affiliation(s)
- Zhongmin Liu
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Jia Wang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Hang Cheng
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084; Joint Graduate Program of Peking-Tsinghua-NIBS, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Xin Ke
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Lei Sun
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Qiangfeng Cliff Zhang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China 100084.
| |
Collapse
|
46
|
Structure of Schlafen13 reveals a new class of tRNA/rRNA- targeting RNase engaged in translational control. Nat Commun 2018; 9:1165. [PMID: 29563550 PMCID: PMC5862951 DOI: 10.1038/s41467-018-03544-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/20/2018] [Indexed: 01/07/2023] Open
Abstract
Cleavage of transfer (t)RNA and ribosomal (r)RNA are critical and conserved steps of translational control for cells to overcome varied environmental stresses. However, enzymes that are responsible for this event have not been fully identified in high eukaryotes. Here, we report a mammalian tRNA/rRNA-targeting endoribonuclease: SLFN13, a member of the Schlafen family. Structural study reveals a unique pseudo-dimeric U-pillow-shaped architecture of the SLFN13 N'-domain that may clamp base-paired RNAs. SLFN13 is able to digest tRNAs and rRNAs in vitro, and the endonucleolytic cleavage dissevers 11 nucleotides from the 3'-terminus of tRNA at the acceptor stem. The cytoplasmically localised SLFN13 inhibits protein synthesis in 293T cells. Moreover, SLFN13 restricts HIV replication in a nucleolytic activity-dependent manner. According to these observations, we term SLFN13 RNase S13. Our study provides insights into the modulation of translational machinery in high eukaryotes, and sheds light on the functional mechanisms of the Schlafen family.
Collapse
|
47
|
Masliah G, Maris C, König SL, Yulikov M, Aeschimann F, Malinowska AL, Mabille J, Weiler J, Holla A, Hunziker J, Meisner-Kober N, Schuler B, Jeschke G, Allain FHT. Structural basis of siRNA recognition by TRBP double-stranded RNA binding domains. EMBO J 2018; 37:embj.201797089. [PMID: 29449323 PMCID: PMC5852647 DOI: 10.15252/embj.201797089] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 11/23/2022] Open
Abstract
The accurate cleavage of pre‐micro(mi)RNAs by Dicer and mi/siRNA guide strand selection are important steps in forming the RNA‐induced silencing complex (RISC). The role of Dicer binding partner TRBP in these processes remains poorly understood. Here, we solved the solution structure of the two N‐terminal dsRNA binding domains (dsRBDs) of TRBP in complex with a functionally asymmetric siRNA using NMR, EPR, and single‐molecule spectroscopy. We find that siRNA recognition by the dsRBDs is not sequence‐specific but rather depends on the RNA shape. The two dsRBDs can swap their binding sites, giving rise to two equally populated, pseudo‐symmetrical complexes, showing that TRBP is not a primary sensor of siRNA asymmetry. Using our structure to model a Dicer‐TRBP‐siRNA ternary complex, we show that TRBP's dsRBDs and Dicer's RNase III domains bind a canonical 19 base pair siRNA on opposite sides, supporting a mechanism whereby TRBP influences Dicer‐mediated cleavage accuracy by binding the dsRNA region of the pre‐miRNA during Dicer cleavage.
Collapse
Affiliation(s)
- Gregoire Masliah
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
| | - Christophe Maris
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
| | | | - Maxim Yulikov
- Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland
| | | | - Anna L Malinowska
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Julie Mabille
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Jan Weiler
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Andrea Holla
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Juerg Hunziker
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Benjamin Schuler
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland
| | - Frederic H-T Allain
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
| |
Collapse
|
48
|
Sinha NK, Iwasa J, Shen PS, Bass BL. Dicer uses distinct modules for recognizing dsRNA termini. Science 2018; 359:329-334. [PMID: 29269422 PMCID: PMC6154394 DOI: 10.1126/science.aaq0921] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/11/2017] [Indexed: 12/19/2022]
Abstract
Invertebrates rely on Dicer to cleave viral double-stranded RNA (dsRNA), and Drosophila Dicer-2 distinguishes dsRNA substrates by their termini. Blunt termini promote processive cleavage, while 3' overhanging termini are cleaved distributively. To understand this discrimination, we used cryo-electron microscopy to solve structures of Drosophila Dicer-2 alone and in complex with blunt dsRNA. Whereas the Platform-PAZ domains have been considered the only Dicer domains that bind dsRNA termini, unexpectedly, we found that the helicase domain is required for binding blunt, but not 3' overhanging, termini. We further showed that blunt dsRNA is locally unwound and threaded through the helicase domain in an adenosine triphosphate-dependent manner. Our studies reveal a previously unrecognized mechanism for optimizing antiviral defense and set the stage for the discovery of helicase-dependent functions in other Dicers.
Collapse
Affiliation(s)
- Niladri K. Sinha
- Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Janet Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Peter S. Shen
- Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Brenda L. Bass
- Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA
| |
Collapse
|
49
|
Rath EC, Pitman S, Cho KH, Bai Y. Identification of streptococcal small RNAs that are putative targets of RNase III through bioinformatics analysis of RNA sequencing data. BMC Bioinformatics 2017; 18:540. [PMID: 29297355 PMCID: PMC5751559 DOI: 10.1186/s12859-017-1897-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Small noncoding regulatory RNAs (sRNAs) are post-transcriptional regulators, regulating mRNAs, proteins, and DNA in bacteria. One class of sRNAs, trans-acting sRNAs, are the most abundant sRNAs transcribed from the intergenic regions (IGRs) of the bacterial genome. In Streptococcus pyogenes, a common and potentially deadly pathogen, many sRNAs have been identified, but only a few have been studied. The goal of this study is to identify trans-acting sRNAs that can be substrates of RNase III. The endoribonuclease RNase III cleaves double stranded RNAs, which can be formed during the interaction between an sRNA and target mRNAs. Results For this study, we created an RNase III null mutant of Streptococcus pyogenes and its RNA sequencing (RNA-Seq) data were analyzed and compared to that of the wild-type. First, we developed a custom script that can detect intergenic regions of the S. pyogenes genome. A differential expression analysis with Cufflinks and Stringtie was then performed to identify the intergenic regions whose expression was influenced by the RNase III gene deletion. Conclusion This analysis yielded 12 differentially expressed regions with >|2| fold change and p ≤ 0.05. Using Artemis and Bamview genome viewers, these regions were visually verified leaving 6 putative sRNAs. This study not only expanded our knowledge on novel sRNAs but would also give us new insight into sRNA degradation.
Collapse
Affiliation(s)
- Ethan C Rath
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA
| | - Stephanie Pitman
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA
| | - Kyu Hong Cho
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA.
| | - Yongsheng Bai
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA. .,The Center for Genomic Advocacy, Indiana State University, Terre Haute, IN, 47809, USA.
| |
Collapse
|
50
|
Charbonnel C, Niazi AK, Elvira-Matelot E, Nowak E, Zytnicki M, de Bures A, Jobet E, Opsomer A, Shamandi N, Nowotny M, Carapito C, Reichheld JP, Vaucheret H, Sáez-Vásquez J. The siRNA suppressor RTL1 is redox-regulated through glutathionylation of a conserved cysteine in the double-stranded-RNA-binding domain. Nucleic Acids Res 2017; 45:11891-11907. [PMID: 28981840 PMCID: PMC5714217 DOI: 10.1093/nar/gkx820] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 09/13/2017] [Indexed: 01/20/2023] Open
Abstract
RNase III enzymes cleave double stranded (ds)RNA. This is an essential step for regulating the processing of mRNA, rRNA, snoRNA and other small RNAs, including siRNA and miRNA. Arabidopsis thaliana encodes nine RNase III: four DICER-LIKE (DCL) and five RNASE THREE LIKE (RTL). To better understand the molecular functions of RNase III in plants we developed a biochemical assay using RTL1 as a model. We show that RTL1 does not degrade dsRNA randomly, but recognizes specific duplex sequences to direct accurate cleavage. Furthermore, we demonstrate that RNase III and dsRNA binding domains (dsRBD) are both required for dsRNA cleavage. Interestingly, the four DCL and the three RTL that carry dsRBD share a conserved cysteine (C230 in Arabidopsis RTL1) in their dsRBD. C230 is essential for RTL1 and DCL1 activities and is subjected to post-transcriptional modification. Indeed, under oxidizing conditions, glutathionylation of C230 inhibits RTL1 cleavage activity in a reversible manner involving glutaredoxins. We conclude that the redox state of the dsRBD ensures a fine-tune regulation of dsRNA processing by plant RNase III.
Collapse
Affiliation(s)
- Cyril Charbonnel
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Adnan K Niazi
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Emilie Elvira-Matelot
- Institut Jean-Pierre Bourgin, UMR1318 INRA AgroParisTech CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Elzbieta Nowak
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | | | - Anne de Bures
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Edouard Jobet
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Alisson Opsomer
- Laboratoire de Spectrométrie de Masse BioOrganique,Université de Strasbourg, CNRS, IPHC UMR 7178, 67037 Strasbourg, France
| | - Nahid Shamandi
- Institut Jean-Pierre Bourgin, UMR1318 INRA AgroParisTech CNRS, Université Paris-Saclay, 78000 Versailles, France.,Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse BioOrganique,Université de Strasbourg, CNRS, IPHC UMR 7178, 67037 Strasbourg, France
| | - Jean-Philippe Reichheld
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, UMR1318 INRA AgroParisTech CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Julio Sáez-Vásquez
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France.,University of Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| |
Collapse
|