251
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Gilmore JL, Yoshida A, Hejna JA, Takeyasu K. Visualization of conformational variability in the domains of long single-stranded RNA molecules. Nucleic Acids Res 2017; 45:8493-8507. [PMID: 28591846 PMCID: PMC5737216 DOI: 10.1093/nar/gkx502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 06/04/2017] [Indexed: 01/05/2023] Open
Abstract
We demonstrate an application of atomic force microscopy (AFM) for the structural analysis of long single-stranded RNA (>1 kb), focusing on 28S ribosomal RNA (rRNA). Generally, optimization of the conditions required to obtain three-dimensional (3D) structures of long RNA molecules is a challenging or nearly impossible process. In this study, we overcome these limitations by developing a method using AFM imaging combined with automated, MATLAB-based image analysis algorithms for extracting information about the domain organization of single RNA molecules. We examined the 5 kb human 28S rRNA since it is the largest RNA molecule for which a 3D structure is available. As a proof of concept, we determined a domain structure that is in accordance with previously described secondary structural models. Importantly, we identified four additional small (200–300 nt), previously unreported domains present in these molecules. Moreover, the single-molecule nature of our method enabled us to report on the relative conformational variability of each domain structure identified, and inter-domain associations within subsets of molecules leading to molecular compaction, which may shed light on the process of how these molecules fold into the final tertiary structure.
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Affiliation(s)
- Jamie L Gilmore
- Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Yoshida-konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Aiko Yoshida
- Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Yoshida-konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - James A Hejna
- Laboratory of Science Communication, Kyoto University Graduate School of Biostudies, Yoshida-konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kunio Takeyasu
- Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Yoshida-konoe, Sakyo-ku, Kyoto 606-8501, Japan.,Institute of Biotechnology, National Taiwan University, 4F, No. 81, Chang-Xing St, Taipei 106, Taiwan
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252
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Plasma assisted surface treatments of biomaterials. Biophys Chem 2017; 229:151-164. [DOI: 10.1016/j.bpc.2017.07.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 02/02/2023]
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253
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Nygaard R, Romaniuk JAH, Rice DM, Cegelski L. Whole Ribosome NMR: Dipolar Couplings and Contributions to Whole Cells. J Phys Chem B 2017; 121:9331-9335. [PMID: 28901760 DOI: 10.1021/acs.jpcb.7b06736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solid-state NMR is a powerful tool for quantifying chemical composition and structure in complex assemblies and even whole cells. We employed N{P} REDOR NMR to obtain atomic-level distance propensities in intact 15N-labeled E. coli ribosomes. The experimental REDOR dephasing of shift-resolved lysyl amine nitrogens by phosphorus was comparable to that expected from a calculation of N-P distances involving the lysines included in the crystal structure coordinates. Among the nitrogen contributions to the REDOR spectra, the strongest dephasing emerged from the dipolar couplings to phosphorus involving nitrogen peaks ascribed primarily to rRNA, and the weakest dephasing arose from protein amide nitrogens. This approach is applicable to any macromolecular system and provides quantitative comparisons of distance proximities between shift-resolved nuclei of one type and heteronuclear dephasing spins. Enhanced molecular specificity could be achieved through the use of spectroscopic filters or specific labeling. Furthermore, ribosome 13C and 15N CPMAS spectra were compared with those of whole cells from which the ribosomes were isolated. Whole-cell signatures of ribosomes were identified and should be of value in comparing overall cellular ribosome content in whole-cell samples.
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Affiliation(s)
- Rie Nygaard
- Department of Chemistry, Stanford University , 380 Roth Way, Stanford California 94305, United States
| | - Joseph A H Romaniuk
- Department of Chemistry, Stanford University , 380 Roth Way, Stanford California 94305, United States
| | - David M Rice
- Department of Chemistry, Stanford University , 380 Roth Way, Stanford California 94305, United States
| | - Lynette Cegelski
- Department of Chemistry, Stanford University , 380 Roth Way, Stanford California 94305, United States
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254
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Moore PB. Structural biology: Past, present, and future. N Biotechnol 2017; 38:29-35. [PMID: 27498255 DOI: 10.1016/j.nbt.2016.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/19/2016] [Indexed: 11/19/2022]
Abstract
In March 2014, a symposium was held at Aarhus University to commemorate the 40th anniversary of the founding of its Division of Biostructural Chemistry by Professor Brian Clark. This article is a lightly edited version of the talk the author gave to open that event. It consists of some reflections about the discipline known as structural biology, and some comments about the author's interactions with Professor Clark and the Division of Biostructural Chemistry over the years.
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Affiliation(s)
- Peter B Moore
- Department of Chemistry, Yale University, PO Box 208107, New Haven, CT, USA.
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255
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Specific Chemical Approaches for Studying Mammalian Ribosomes Complexed with Ligands Involved in Selenoprotein Synthesis. Methods Mol Biol 2017. [PMID: 28917038 DOI: 10.1007/978-1-4939-7258-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Chemical approaches are very powerful tools for investigating the molecular structure and architecture of large ribonucleoprotein complexes involving ribosomes and other components of the translation system. Application of RNA nucleotide-specific and cross-linking reagents of a broad specificity range allows the researcher to obtain information on the sites of ligand binding to the ribosome and to each other as well as on the RNA rearrangements caused by the binding. Here, we describe specific chemical approaches including chemical probing and site-directed or bifunctional reagent-mediated cross-linking, which have been used for exploring the mechanism of selenocysteine insertion into a polypeptide chain by mammalian ribosomes.
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256
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Chetty CJ, Ferreira E, Jovanovic K, Weiss SFT. Knockdown of LRP/LR induces apoptosis in pancreatic cancer and neuroblastoma cells through activation of caspases. Exp Cell Res 2017; 360:264-272. [PMID: 28899658 DOI: 10.1016/j.yexcr.2017.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022]
Abstract
The 37kDa/67kDa laminin receptor (LRP/LR) serves various physiological and pathological roles such as enhancing tumour-related processes including metastasis, angiogenesis, cellular viability and telomerase activation in cancerous cell lines. The present study investigates the effect of siRNA mediated downregulation of LRP/LR on pancreatic cancer (AsPC-1) and neuroblastoma (IMR-32) cells. MTT and BrdU assays revealed that siRNA mediated downregulation of LRP resulted in a significant reduction in cell viability and cell proliferation. In addition, knock-down of LRP resulted in phosphatidylserine externalization, diminished nuclear integrity and significantly enhanced caspase-3 activity, which is indicative of apoptosis. LRP downregulation resulted in a significant increase in caspase-8 activity in IMR-32 cells and enhanced caspase-8 and 9 activity in AsPC-1 cells. These data recommend siRNA mediated knock-down of LRP as a potential therapeutic avenue for the treatment of pancreatic cancer and neuroblastoma.
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Affiliation(s)
- Carryn J Chetty
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa
| | - Eloise Ferreira
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa
| | - Katarina Jovanovic
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa
| | - Stefan F T Weiss
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa.
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257
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Bäuerlein FJB, Saha I, Mishra A, Kalemanov M, Martínez-Sánchez A, Klein R, Dudanova I, Hipp MS, Hartl FU, Baumeister W, Fernández-Busnadiego R. In Situ Architecture and Cellular Interactions of PolyQ Inclusions. Cell 2017; 171:179-187.e10. [PMID: 28890085 DOI: 10.1016/j.cell.2017.08.009] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/30/2017] [Accepted: 08/07/2017] [Indexed: 02/06/2023]
Abstract
Expression of many disease-related aggregation-prone proteins results in cytotoxicity and the formation of large intracellular inclusion bodies. To gain insight into the role of inclusions in pathology and the in situ structure of protein aggregates inside cells, we employ advanced cryo-electron tomography methods to analyze the structure of inclusions formed by polyglutamine (polyQ)-expanded huntingtin exon 1 within their intact cellular context. In primary mouse neurons and immortalized human cells, polyQ inclusions consist of amyloid-like fibrils that interact with cellular endomembranes, particularly of the endoplasmic reticulum (ER). Interactions with these fibrils lead to membrane deformation, the local impairment of ER organization, and profound alterations in ER membrane dynamics at the inclusion periphery. These results suggest that aberrant interactions between fibrils and endomembranes contribute to the deleterious cellular effects of protein aggregation. VIDEO ABSTRACT.
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Affiliation(s)
- Felix J B Bäuerlein
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Itika Saha
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Archana Mishra
- Department of Molecules, Signaling, and Development, Max Planck Institute of Neurobiology, 82152 Martinsried, Germany
| | - Maria Kalemanov
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Graduate School of Quantitative Biosciences Munich, 81337 Munich, Germany
| | - Antonio Martínez-Sánchez
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Rüdiger Klein
- Department of Molecules, Signaling, and Development, Max Planck Institute of Neurobiology, 82152 Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 80336 Munich, Germany
| | - Irina Dudanova
- Department of Molecules, Signaling, and Development, Max Planck Institute of Neurobiology, 82152 Martinsried, Germany
| | - Mark S Hipp
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 80336 Munich, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 80336 Munich, Germany.
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
| | - Rubén Fernández-Busnadiego
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
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258
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Gopanenko AV, Malygin AA, Tupikin AE, Laktionov PP, Kabilov MR, Karpova GG. Human ribosomal protein eS1 is engaged in cellular events related to processing and functioning of U11 snRNA. Nucleic Acids Res 2017; 45:9121-9137. [PMID: 28666385 PMCID: PMC5587755 DOI: 10.1093/nar/gkx559] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 06/15/2017] [Accepted: 06/20/2017] [Indexed: 01/22/2023] Open
Abstract
Ribosomal proteins are involved in many cellular processes through interactions with various RNAs. Here, applying the photoactivatable-ribonucleoside-enhanced cross-linking and immunoprecipitation approach to HEK293 cells overproducing ribosomal protein (rp) eS1, we determined the products of RNU5A-1 and RNU11 genes encoding U5 and U11 snRNAs as the RNA partners of ribosome-unbound rp eS1. U11 pre-snRNA-associated rp eS1 was revealed in the cytoplasm and nucleus where rp eS1-bound U11/U12 di-snRNP was also found. Utilizing recombinant rp eS1 and 4-thiouridine-containing U11 snRNA transcript, we identified an N-terminal peptide contacting the U-rich sequence in the Sm site-containing RNA region. We also showed that the rp eS1 binding site on U11 snRNA is located in the cleft between stem-loops I and III and that its structure mimics the respective site on the 18S rRNA. It was found that cell depletion of rp eS1 leads to a decrease in the splicing efficiency of minor introns and to an increase in the level of U11 pre-snRNA with the unprocessed 3' terminus. Our findings demonstrate the engagement of human rp eS1 in events related to the U11 snRNA processing and to minor-class splicing. Contacts of rp eS1 with U5 snRNA in the minor pre-catalytic spliceosome are discussed.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Escherichia coli/genetics
- Escherichia coli/metabolism
- HEK293 Cells
- Humans
- Introns
- Models, Molecular
- Nucleic Acid Conformation
- Protein Biosynthesis
- Protein Conformation, alpha-Helical
- Protein Interaction Domains and Motifs
- RNA Splicing
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- RNA, Small Nuclear/chemistry
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
- Spliceosomes/genetics
- Spliceosomes/metabolism
- Thiouridine/metabolism
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Affiliation(s)
- Alexander V. Gopanenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
- Department of Molecular Biology, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Alexey A. Malygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
- Department of Molecular Biology, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Alexey E. Tupikin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Pavel P. Laktionov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Marsel R. Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Galina G. Karpova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
- Department of Molecular Biology, Novosibirsk State University, Novosibirsk 630090, Russia
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259
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Low-dose cryo electron ptychography via non-convex Bayesian optimization. Sci Rep 2017; 7:9883. [PMID: 28851880 PMCID: PMC5575234 DOI: 10.1038/s41598-017-07488-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/27/2017] [Indexed: 11/23/2022] Open
Abstract
Electron ptychography has seen a recent surge of interest for phase sensitive imaging at atomic or near-atomic resolution. However, applications are so far mainly limited to radiation-hard samples, because the required doses are too high for imaging biological samples at high resolution. We propose the use of non-convex Bayesian optimization to overcome this problem, and show via numerical simulations that the dose required for successful reconstruction can be reduced by two orders of magnitude compared to previous experiments. As an important application we suggest to use this method for imaging single biological macromolecules at cryogenic temperatures and demonstrate 2D single-particle reconstructions from simulated data with a resolution up to 5.4 Å at a dose of 20e−/Å2. When averaging over only 30 low-dose datasets, a 2D resolution around 3.5 Å is possible for macromolecular complexes even below 100 kDa. With its independence from the microscope transfer function, direct recovery of phase contrast, and better scaling of signal-to-noise ratio, low-dose cryo electron ptychography may become a promising alternative to Zernike phase-contrast microscopy.
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260
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Li Z, Guo Q, Zheng L, Ji Y, Xie YT, Lai DH, Lun ZR, Suo X, Gao N. Cryo-EM structures of the 80S ribosomes from human parasites Trichomonas vaginalis and Toxoplasma gondii. Cell Res 2017; 27:1275-1288. [PMID: 28809395 DOI: 10.1038/cr.2017.104] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 05/27/2017] [Accepted: 06/27/2017] [Indexed: 12/20/2022] Open
Abstract
As an indispensable molecular machine universal in all living organisms, the ribosome has been selected by evolution to be the natural target of many antibiotics and small-molecule inhibitors. High-resolution structures of pathogen ribosomes are crucial for understanding the general and unique aspects of translation control in disease-causing microbes. With cryo-electron microscopy technique, we have determined structures of the cytosolic ribosomes from two human parasites, Trichomonas vaginalis and Toxoplasma gondii, at resolution of 3.2-3.4 Å. Although the ribosomal proteins from both pathogens are typical members of eukaryotic families, with a co-evolution pattern between certain species-specific insertions/extensions and neighboring ribosomal RNA (rRNA) expansion segments, the sizes of their rRNAs are sharply different. Very interestingly, rRNAs of T. vaginalis are in size comparable to prokaryotic counterparts, with nearly all the eukaryote-specific rRNA expansion segments missing. These structures facilitate the dissection of evolution path for ribosomal proteins and RNAs, and may aid in design of novel translation inhibitors.
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Affiliation(s)
- Zhifei Li
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiang Guo
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lvqin Zheng
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yongsheng Ji
- Anhui Provincial Laboratory of Pathogen Biology, Anhui Key Laboratory of Zoonoses, Department of Microbiology and Parasitology, Anhui Medical University, Hefei, Anhui 230022, China
| | - Yi-Ting Xie
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - De-Hua Lai
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Zhao-Rong Lun
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, Key Laboratory of Tropical Disease Control (Sun Yat-Sen University), Ministry of Education, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Xun Suo
- State Key Laboratory of Agrobiotechnology &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
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261
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Graf M, Arenz S, Huter P, Dönhöfer A, Novácek J, Wilson DN. Cryo-EM structure of the spinach chloroplast ribosome reveals the location of plastid-specific ribosomal proteins and extensions. Nucleic Acids Res 2017; 45:2887-2896. [PMID: 27986857 PMCID: PMC5389730 DOI: 10.1093/nar/gkw1272] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/06/2016] [Indexed: 11/30/2022] Open
Abstract
Ribosomes are the protein synthesizing machines of the cell. Recent advances in cryo-EM have led to the determination of structures from a variety of species, including bacterial 70S and eukaryotic 80S ribosomes as well as mitoribosomes from eukaryotic mitochondria, however, to date high resolution structures of plastid 70S ribosomes have been lacking. Here we present a cryo-EM structure of the spinach chloroplast 70S ribosome, with an average resolution of 5.4 Å for the small 30S subunit and 3.6 Å for the large 50S ribosomal subunit. The structure reveals the location of the plastid-specific ribosomal proteins (RPs) PSRP1, PSRP4, PSRP5 and PSRP6 as well as the numerous plastid-specific extensions of the RPs. We discover many features by which the plastid-specific extensions stabilize the ribosome via establishing additional interactions with surrounding ribosomal RNA and RPs. Moreover, we identify a large conglomerate of plastid-specific protein mass adjacent to the tunnel exit site that could facilitate interaction of the chloroplast ribosome with the thylakoid membrane and the protein-targeting machinery. Comparing the Escherichia coli 70S ribosome with that of the spinach chloroplast ribosome provides detailed insight into the co-evolution of RP and rRNA.
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Affiliation(s)
- Michael Graf
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany
| | - Stefan Arenz
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany
| | - Paul Huter
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany
| | - Alexandra Dönhöfer
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany
| | - Jirí Novácek
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Daniel N Wilson
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, 81377 Munich, Germany.,Department of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
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262
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Rogell B, Fischer B, Rettel M, Krijgsveld J, Castello A, Hentze MW. Specific RNP capture with antisense LNA/DNA mixmers. RNA (NEW YORK, N.Y.) 2017; 23:1290-1302. [PMID: 28476952 PMCID: PMC5513073 DOI: 10.1261/rna.060798.117] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/25/2017] [Indexed: 05/07/2023]
Abstract
RNA-binding proteins (RBPs) play essential roles in RNA biology, responding to cellular and environmental stimuli to regulate gene expression. Important advances have helped to determine the (near) complete repertoires of cellular RBPs. However, identification of RBPs associated with specific transcripts remains a challenge. Here, we describe "specific ribonucleoprotein (RNP) capture," a versatile method for the determination of the proteins bound to specific transcripts in vitro and in cellular systems. Specific RNP capture uses UV irradiation to covalently stabilize protein-RNA interactions taking place at "zero distance." Proteins bound to the target RNA are captured by hybridization with antisense locked nucleic acid (LNA)/DNA oligonucleotides covalently coupled to a magnetic resin. After stringent washing, interacting proteins are identified by quantitative mass spectrometry. Applied to in vitro extracts, specific RNP capture identifies the RBPs bound to a reporter mRNA containing the Sex-lethal (Sxl) binding motifs, revealing that the Sxl homolog sister of Sex lethal (Ssx) displays similar binding preferences. This method also revealed the repertoire of RBPs binding to 18S or 28S rRNAs in HeLa cells, including previously unknown rRNA-binding proteins.
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Affiliation(s)
- Birgit Rogell
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Bernd Fischer
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Mandy Rettel
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jeroen Krijgsveld
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Alfredo Castello
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Matthias W Hentze
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
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263
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Locati MD, Pagano JFB, Girard G, Ensink WA, van Olst M, van Leeuwen S, Nehrdich U, Spaink HP, Rauwerda H, Jonker MJ, Dekker RJ, Breit TM. Expression of distinct maternal and somatic 5.8S, 18S, and 28S rRNA types during zebrafish development. RNA (NEW YORK, N.Y.) 2017; 23:1188-1199. [PMID: 28500251 PMCID: PMC5513064 DOI: 10.1261/rna.061515.117] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/09/2017] [Indexed: 05/27/2023]
Abstract
There is mounting evidence that the ribosome is not a static translation machinery, but a cell-specific, adaptive system. Ribosomal variations have mostly been studied at the protein level, even though the essential transcriptional functions are primarily performed by rRNAs. At the RNA level, oocyte-specific 5S rRNAs are long known for Xenopus. Recently, we described for zebrafish a similar system in which the sole maternal-type 5S rRNA present in eggs is replaced completely during embryonic development by a somatic-type. Here, we report the discovery of an analogous system for the 45S rDNA elements: 5.8S, 18S, and 28S. The maternal-type 5.8S, 18S, and 28S rRNA sequences differ substantially from those of the somatic-type, plus the maternal-type rRNAs are also replaced by the somatic-type rRNAs during embryogenesis. We discuss the structural and functional implications of the observed sequence differences with respect to the translational functions of the 5.8S, 18S, and 28S rRNA elements. Finally, in silico evidence suggests that expansion segments (ES) in 18S rRNA, previously implicated in ribosome-mRNA interaction, may have a preference for interacting with specific mRNA genes. Taken together, our findings indicate that two distinct types of ribosomes exist in zebrafish during development, each likely conducting the translation machinery in a unique way.
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MESH Headings
- Animals
- Base Pairing
- Base Sequence
- DNA, Ribosomal/genetics
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/metabolism
- Nucleic Acid Conformation
- RNA Processing, Post-Transcriptional
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- RNA, Ribosomal, 28S/genetics
- RNA, Ribosomal, 28S/metabolism
- RNA, Ribosomal, 5.8S/genetics
- RNA, Ribosomal, 5.8S/metabolism
- Ribosomes/metabolism
- Sequence Alignment
- Zebrafish/genetics
- Zebrafish/growth & development
- Zebrafish/metabolism
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Affiliation(s)
- Mauro D Locati
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Johanna F B Pagano
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Geneviève Girard
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Wim A Ensink
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Marina van Olst
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Selina van Leeuwen
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Ulrike Nehrdich
- Department of Molecular Cell Biology, Institute of Biology, Leiden University, Gorlaeus Laboratories-Cell Observatorium, Leiden 2333 CE, the Netherlands
| | - Herman P Spaink
- Department of Molecular Cell Biology, Institute of Biology, Leiden University, Gorlaeus Laboratories-Cell Observatorium, Leiden 2333 CE, the Netherlands
| | - Han Rauwerda
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Martijs J Jonker
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Rob J Dekker
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
| | - Timo M Breit
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1090 GE, the Netherlands
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264
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Ubiquitination of stalled ribosome triggers ribosome-associated quality control. Nat Commun 2017; 8:159. [PMID: 28757607 PMCID: PMC5534433 DOI: 10.1038/s41467-017-00188-1] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/08/2017] [Indexed: 11/08/2022] Open
Abstract
Translation arrest by polybasic sequences induces ribosome stalling, and the arrest product is degraded by the ribosome-mediated quality control (RQC) system. Here we report that ubiquitination of the 40S ribosomal protein uS10 by the E3 ubiquitin ligase Hel2 (or RQT1) is required for RQC. We identify a RQC-trigger (RQT) subcomplex composed of the RNA helicase-family protein Slh1/Rqt2, the ubiquitin-binding protein Cue3/Rqt3, and yKR023W/Rqt4 that is required for RQC. The defects in RQC of the RQT mutants correlate with sensitivity to anisomycin, which stalls ribosome at the rotated form. Cryo-electron microscopy analysis reveals that Hel2-bound ribosome are dominantly the rotated form with hybrid tRNAs. Ribosome profiling reveals that ribosomes stalled at the rotated state with specific pairs of codons at P-A sites serve as RQC substrates. Rqt1 specifically ubiquitinates these arrested ribosomes to target them to the RQT complex, allowing subsequent RQC reactions including dissociation of the stalled ribosome into subunits.Several protein quality control mechanisms are in place to trigger the rapid degradation of aberrant polypeptides and mRNAs. Here the authors describe a mechanism of ribosome-mediated quality control that involves the ubiquitination of ribosomal proteins by the E3 ubiquitin ligase Hel2/RQT1.
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265
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Generation of ribosome imprinted polymers for sensitive detection of translational responses. Sci Rep 2017; 7:6542. [PMID: 28747643 PMCID: PMC5529568 DOI: 10.1038/s41598-017-06970-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/21/2017] [Indexed: 01/01/2023] Open
Abstract
Whilst the profiling of the transcriptome and proteome even of single-cells becomes feasible, the analysis of the translatome, which refers to all messenger RNAs (mRNAs) engaged with ribosomes for protein synthesis, is still an elaborate procedure requiring millions of cells. Herein, we report the generation and use of "smart materials", namely molecularly imprinted polymers (MIPs) to facilitate the isolation of ribosomes and translated mRNAs from merely 1,000 cells. In particular, we show that a hydrogel-based ribosome imprinted polymer could recover ribosomes and associated mRNAs from human, simian and mice cellular extracts, but did not selectively enrich yeast ribosomes, thereby demonstrating selectivity. Furthermore, ribosome imprinted polymers enabled the sensitive measurement of an mRNA translational regulatory event, requiring 1,000-fold less cells than current methodologies. These results provide first evidence for the suitability of MIPs to selectively recover ribonucleoprotein complexes such as ribosomes, founding a novel means for sensitive detection of gene regulation.
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266
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Efficient and Accurate Translation Initiation Directed by TISU Involves RPS3 and RPS10e Binding and Differential Eukaryotic Initiation Factor 1A Regulation. Mol Cell Biol 2017; 37:MCB.00150-17. [PMID: 28584194 DOI: 10.1128/mcb.00150-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/17/2017] [Indexed: 01/20/2023] Open
Abstract
Canonical translation initiation involves ribosomal scanning, but short 5' untranslated region (5'UTR) mRNAs are translated in a scanning-independent manner. The extent and mechanism of scanning-independent translation are not fully understood. Here we report that short 5'UTR mRNAs constitute a substantial fraction of the translatome. Short 5'UTR mRNAs are enriched with TISU (translation initiator of short 5'UTR), a 12-nucleotide element directing efficient scanning-independent translation. Comprehensive mutagenesis revealed that each AUG codon-flanking nucleotide of TISU contributes to translational strength, but only a few are important for accuracy. Using site-specific UV cross-linking of ribosomal complexes assembled on TISU mRNA, we demonstrate specific binding of TISU to ribosomal proteins at the E and A sites. We identified RPS3 as the major TISU binding protein in the 48S complex A site. Upon 80S complex formation, RPS3 interaction is weakened and switched to RPS10e (formerly called RPS10). We further demonstrate that TISU is particularly dependent on eukaryotic initiation factor 1A (eIF1A) which interacts with both RPS3 and RPS10e. Our findings suggest that the cap-recruited ribosome specifically binds the TISU nucleotides at the A and E sites in cooperation with eIF1A to promote scanning arrest.
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267
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Sap KA, Bezstarosti K, Dekkers DHW, Voets O, Demmers JAA. Quantitative Proteomics Reveals Extensive Changes in the Ubiquitinome after Perturbation of the Proteasome by Targeted dsRNA-Mediated Subunit Knockdown in Drosophila. J Proteome Res 2017; 16:2848-2862. [DOI: 10.1021/acs.jproteome.7b00156] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Karen A. Sap
- Proteomics
Center, ‡Netherlands Proteomics Center, and §Department of Biochemistry, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Karel Bezstarosti
- Proteomics
Center, ‡Netherlands Proteomics Center, and §Department of Biochemistry, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Dick H. W. Dekkers
- Proteomics
Center, ‡Netherlands Proteomics Center, and §Department of Biochemistry, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Olaf Voets
- Proteomics
Center, ‡Netherlands Proteomics Center, and §Department of Biochemistry, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| | - Jeroen A. A. Demmers
- Proteomics
Center, ‡Netherlands Proteomics Center, and §Department of Biochemistry, Erasmus University Medical Center, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
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268
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Garzia A, Jafarnejad SM, Meyer C, Chapat C, Gogakos T, Morozov P, Amiri M, Shapiro M, Molina H, Tuschl T, Sonenberg N. The E3 ubiquitin ligase and RNA-binding protein ZNF598 orchestrates ribosome quality control of premature polyadenylated mRNAs. Nat Commun 2017; 8:16056. [PMID: 28685749 PMCID: PMC5504347 DOI: 10.1038/ncomms16056] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/16/2017] [Indexed: 12/20/2022] Open
Abstract
Cryptic polyadenylation within coding sequences (CDS) triggers ribosome-associated quality control (RQC), followed by degradation of the aberrant mRNA and polypeptide, ribosome disassembly and recycling. Although ribosomal subunit dissociation and nascent peptide degradation are well-understood, the molecular sensors of aberrant mRNAs and their mechanism of action remain unknown. We studied the Zinc Finger Protein 598 (ZNF598) using PAR-CLIP and revealed that it cross-links to tRNAs, mRNAs and rRNAs, thereby placing the protein on translating ribosomes. Cross-linked reads originating from AAA-decoding tRNALys(UUU) were 10-fold enriched over its cellular abundance, and poly-lysine encoded by poly(AAA) induced RQC in a ZNF598-dependent manner. Encounter with translated polyA segments by ZNF598 triggered ubiquitination of several ribosomal proteins, requiring the E2 ubiquitin ligase UBE2D3 to initiate RQC. Considering that human CDS are devoid of >4 consecutive AAA codons, sensing of prematurely placed polyA tails by a specialized RNA-binding protein is a novel nucleic-acid-based surveillance mechanism of RQC. Translation of aberrant mRNAs causes ribosome stalling and translation arrest, followed by recycling of the stalled ribosome complex. Here the authors show that the Zinc Finger Protein 598 (ZNF598/Hel2) is implicated in sensing faulty translation of prematurely polyadenylated mRNAs through the recognition of AAA codons.
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Affiliation(s)
- Aitor Garzia
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Ave, Box 186, New York, New York 10065, USA
| | - Seyed Mehdi Jafarnejad
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Cindy Meyer
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Ave, Box 186, New York, New York 10065, USA
| | - Clément Chapat
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Tasos Gogakos
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Ave, Box 186, New York, New York 10065, USA
| | - Pavel Morozov
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Ave, Box 186, New York, New York 10065, USA
| | - Mehdi Amiri
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Maayan Shapiro
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, New York 10065, USA
| | - Thomas Tuschl
- Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Ave, Box 186, New York, New York 10065, USA
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
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269
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Principles of 60S ribosomal subunit assembly emerging from recent studies in yeast. Biochem J 2017; 474:195-214. [PMID: 28062837 DOI: 10.1042/bcj20160516] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 12/31/2022]
Abstract
Ribosome biogenesis requires the intertwined processes of folding, modification, and processing of ribosomal RNA, together with binding of ribosomal proteins. In eukaryotic cells, ribosome assembly begins in the nucleolus, continues in the nucleoplasm, and is not completed until after nascent particles are exported to the cytoplasm. The efficiency and fidelity of ribosome biogenesis are facilitated by >200 assembly factors and ∼76 different small nucleolar RNAs. The pathway is driven forward by numerous remodeling events to rearrange the ribonucleoprotein architecture of pre-ribosomes. Here, we describe principles of ribosome assembly that have emerged from recent studies of biogenesis of the large ribosomal subunit in the yeast Saccharomyces cerevisiae We describe tools that have empowered investigations of ribosome biogenesis, and then summarize recent discoveries about each of the consecutive steps of subunit assembly.
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270
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Shi Z, Fujii K, Kovary KM, Genuth NR, Röst HL, Teruel MN, Barna M. Heterogeneous Ribosomes Preferentially Translate Distinct Subpools of mRNAs Genome-wide. Mol Cell 2017. [PMID: 28625553 DOI: 10.1016/j.molcel.2017.05.021] [Citation(s) in RCA: 392] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Emerging studies have linked the ribosome to more selective control of gene regulation. However, an outstanding question is whether ribosome heterogeneity at the level of core ribosomal proteins (RPs) exists and enables ribosomes to preferentially translate specific mRNAs genome-wide. Here, we measured the absolute abundance of RPs in translating ribosomes and profiled transcripts that are enriched or depleted from select subsets of ribosomes within embryonic stem cells. We find that heterogeneity in RP composition endows ribosomes with differential selectivity for translating subpools of transcripts, including those controlling metabolism, cell cycle, and development. As an example, mRNAs enriched in binding to RPL10A/uL1-containing ribosomes are shown to require RPL10A/uL1 for their efficient translation. Within several of these transcripts, this level of regulation is mediated, at least in part, by internal ribosome entry sites. Together, these results reveal a critical functional link between ribosome heterogeneity and the post-transcriptional circuitry of gene expression.
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Affiliation(s)
- Zhen Shi
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Kotaro Fujii
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Kyle M Kovary
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Naomi R Genuth
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Hannes L Röst
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Mary N Teruel
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Maria Barna
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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271
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Tomecki R, Sikorski PJ, Zakrzewska-Placzek M. Comparison of preribosomal RNA processing pathways in yeast, plant and human cells - focus on coordinated action of endo- and exoribonucleases. FEBS Lett 2017; 591:1801-1850. [PMID: 28524231 DOI: 10.1002/1873-3468.12682] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/14/2017] [Accepted: 05/15/2017] [Indexed: 12/17/2022]
Abstract
Proper regulation of ribosome biosynthesis is mandatory for cellular adaptation, growth and proliferation. Ribosome biogenesis is the most energetically demanding cellular process, which requires tight control. Abnormalities in ribosome production have severe consequences, including developmental defects in plants and genetic diseases (ribosomopathies) in humans. One of the processes occurring during eukaryotic ribosome biogenesis is processing of the ribosomal RNA precursor molecule (pre-rRNA), synthesized by RNA polymerase I, into mature rRNAs. It must not only be accurate but must also be precisely coordinated with other phenomena leading to the synthesis of functional ribosomes: RNA modification, RNA folding, assembly with ribosomal proteins and nucleocytoplasmic RNP export. A multitude of ribosome biogenesis factors ensure that these events take place in a correct temporal order. Among them are endo- and exoribonucleases involved in pre-rRNA processing. Here, we thoroughly present a wide spectrum of ribonucleases participating in rRNA maturation, focusing on their biochemical properties, regulatory mechanisms and substrate specificity. We also discuss cooperation between various ribonucleolytic activities in particular stages of pre-rRNA processing, delineating major similarities and differences between three representative groups of eukaryotes: yeast, plants and humans.
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Affiliation(s)
- Rafal Tomecki
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.,Department of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Poland
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272
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Simsek D, Tiu GC, Flynn RA, Byeon GW, Leppek K, Xu AF, Chang HY, Barna M. The Mammalian Ribo-interactome Reveals Ribosome Functional Diversity and Heterogeneity. Cell 2017; 169:1051-1065.e18. [PMID: 28575669 PMCID: PMC5548193 DOI: 10.1016/j.cell.2017.05.022] [Citation(s) in RCA: 265] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 03/13/2017] [Accepted: 05/14/2017] [Indexed: 11/19/2022]
Abstract
During eukaryotic evolution, ribosomes have considerably increased in size, forming a surface-exposed ribosomal RNA (rRNA) shell of unknown function, which may create an interface for yet uncharacterized interacting proteins. To investigate such protein interactions, we establish a ribosome affinity purification method that unexpectedly identifies hundreds of ribosome-associated proteins (RAPs) from categories including metabolism and cell cycle, as well as RNA- and protein-modifying enzymes that functionally diversify mammalian ribosomes. By further characterizing RAPs, we discover the presence of ufmylation, a metazoan-specific post-translational modification (PTM), on ribosomes and define its direct substrates. Moreover, we show that the metabolic enzyme, pyruvate kinase muscle (PKM), interacts with sub-pools of endoplasmic reticulum (ER)-associated ribosomes, exerting a non-canonical function as an RNA-binding protein in the translation of ER-destined mRNAs. Therefore, RAPs interconnect one of life's most ancient molecular machines with diverse cellular processes, providing an additional layer of regulatory potential to protein expression.
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Affiliation(s)
- Deniz Simsek
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Gerald C Tiu
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Ryan A Flynn
- Center for Personal Dynamic Regulomes and Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gun W Byeon
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Kathrin Leppek
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Adele F Xu
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes and Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Maria Barna
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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273
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Chang AT, Tran M, Nikonowicz EP. Structure and Dynamics of the Tetra-A Loop and (A-A)-U Sequence Motif within the Coliphage GA Replicase RNA Operator. Biochemistry 2017; 56:2690-2700. [PMID: 28488852 DOI: 10.1021/acs.biochem.7b00123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The three-dimensional structure of a RNA hairpin containing the RNA operator binding site for bacteriophage GA coat protein is presented. The phage GA operator contains the asymmetric (A-A)-U sequence motif and is capped by a four-adenine (tetra-A) loop. The uridine of the (A-A)-U motif preferentially pairs with the 5'-proximal cross-strand adenine, and the 3'-proximal adenine stacks into the helix. The tetra-A loop is well-ordered with adenine residues 2-4 forming a 3' stack. This loop conformation stands in contrast to the structure of the 5'-AUUA loop of the related phage MS2 operator in which residues 1 and 2 form a 5' stack. The context dependence of the (A-A)-U sequence motif conformation was examined using structures of 76 unique occurrences from the Protein Data Bank. The motif almost always has one adenine bulged and the other adenine adopting an A-U base pair. In the case in which the (A-A)-U motif is flanked by only one Watson-Crick base pair, the adenine adjacent to the flanking base pair tends to bulge; 80% of motifs with a 3' flanking pair have a 3' bulged adenine, and 84% of motifs with a 5' flanking pair have a 5' bulged adenine. The frequencies of 3'- and 5'-proximal adenines bulging are 33 and 67%, respectively, when the (A-A)-U motif is flanked by base pairs on both sides. Although a 3' flanking cytidine correlates (88%) with bulging of the 5'-proximal adenine, no strict dependence on flanking nucleotide identity was identified for the 5' side.
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Affiliation(s)
- Andrew T Chang
- Department of BioSciences, Rice University , Houston, Texas 77251-1892, United States
| | - Michelle Tran
- Department of BioSciences, Rice University , Houston, Texas 77251-1892, United States
| | - Edward P Nikonowicz
- Department of BioSciences, Rice University , Houston, Texas 77251-1892, United States
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274
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Biswas A, Ranjan D, Zubair M, Zeil S, Nasr KA, He J. An Effective Computational Method Incorporating Multiple Secondary Structure Predictions in Topology Determination for Cryo-EM Images. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2017; 14:578-586. [PMID: 27008671 PMCID: PMC5071113 DOI: 10.1109/tcbb.2016.2543721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A key idea in de novo modeling of a medium-resolution density image obtained from cryo-electron microscopy is to compute the optimal mapping between the secondary structure traces observed in the density image and those predicted on the protein sequence. When secondary structures are not determined precisely, either from the image or from the amino acid sequence of the protein, the computational problem becomes more complex. We present an efficient method that addresses the secondary structure placement problem in presence of multiple secondary structure predictions and computes the optimal mapping. We tested the method using 12 simulated images from α-proteins and two Cryo-EM images of α-β proteins. We observed that the rank of the true topologies is consistently improved by using multiple secondary structure predictions instead of a single prediction. The results show that the algorithm is robust and works well even when errors/misses in the predicted secondary structures are present in the image or the sequence. The results also show that the algorithm is efficient and is able to handle proteins with as many as 33 helices.
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Affiliation(s)
- Abhishek Biswas
- Dept. of Computer Science, Old Dominion University, Norfolk, VA 23529
| | - Desh Ranjan
- Dept. of Computer Science, Old Dominion University, Norfolk, VA 23529
| | - Mohammad Zubair
- Dept. of Computer Science, Old Dominion University, Norfolk, VA 23529
| | - Stephanie Zeil
- Dept. of Computer Science, Old Dominion University, Norfolk, VA 23529
| | - Kamal Al Nasr
- Dept. of Computer Science, Tennessee State University, Nashville, TN 37209
| | - Jing He
- Dept. of Computer Science, Old Dominion University, Norfolk, VA 23529
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275
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Exploring contacts of eRF1 with the 3'-terminus of the P site tRNA and mRNA stop signal in the human ribosome at various translation termination steps. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:782-793. [PMID: 28457996 DOI: 10.1016/j.bbagrm.2017.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/20/2017] [Accepted: 04/20/2017] [Indexed: 11/22/2022]
Abstract
Here we employed site-directed cross-linking with the application of tRNA and mRNA analogues bearing an oxidized ribose at the 3'-terminus to investigate mutual arrangement of the main components of translation termination complexes formed on the human 80S ribosome bound with P site deacylated tRNA using eRF1•eRF3•GTP or eRF1 alone. In addition, we applied a model complex obtained in the same way with eRF1•eRF3•GMPPNP. We found that eRF3 content in the complexes with GTP and GMPPNP is similar, proving that eRF3 does not leave the ribosome after GTP hydrolysis. Our cross-linking data allowed determining locations of the 3'-terminus of the P site tRNA relatively the eRF1 M domain and of the mRNA stop signal toward the N domain and the ribosomal decoding site at the nucleotide-peptide resolution level. Our results indicate that locations of these components do not change after peptide release up to post-termination pre-recycling state, and the positioning of the mRNA stop signal remains similar to that when eRF1 recognizes it. Besides, we found that in all the complexes studied eRF1 shielded the N-terminal part of ribosomal protein eS30 from the interaction with the nucleotide adjacent to stop codon observed with pre-termination ribosome free of eRFs. Altogether, our findings brought important information on contacts of the key structural elements of eRF1, tRNA and mRNA in the ribosomal complexes including those mimicking different translation termination steps, thereby providing a deeper understanding of molecular mechanisms underlying events occurring in the course of protein synthesis termination in mammals.
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276
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Simsek D, Barna M. An emerging role for the ribosome as a nexus for post-translational modifications. Curr Opin Cell Biol 2017; 45:92-101. [PMID: 28445788 DOI: 10.1016/j.ceb.2017.02.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/25/2017] [Indexed: 01/01/2023]
Abstract
The ribosome is one of life's most ancient molecular machines that has historically been viewed as a backstage participant in gene regulation, translating the genetic code across all kingdoms of life in a rote-like fashion. However, recent studies suggest that intrinsic components of the ribosome can be regulated and diversified as a means to intricately control the expression of the cellular proteome. In this review, we discuss advances in the characterization of ribosome post-translational modifications (PTMs) from past to present. We specifically focus on emerging examples of ribosome phosphorylation and ubiquitylation, which are beginning to showcase that PTMs of the ribosome are versatile, may have functional consequences for translational control, and are intimately linked to human disease. We further highlight the key questions that remain to be addressed to gain a more complete picture of the array of ribosome PTMs and the upstream enzymes that control them, which may endow ribosomes with greater regulatory potential in gene regulation and control of cellular homeostasis.
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Affiliation(s)
- Deniz Simsek
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Maria Barna
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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277
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Panthu B, Terrier O, Carron C, Traversier A, Corbin A, Balvay L, Lina B, Rosa-Calatrava M, Ohlmann T. The NS1 Protein from Influenza Virus Stimulates Translation Initiation by Enhancing Ribosome Recruitment to mRNAs. J Mol Biol 2017; 429:3334-3352. [PMID: 28433538 DOI: 10.1016/j.jmb.2017.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 03/24/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022]
Abstract
The non-structural protein NS1 of influenza A viruses exerts pleiotropic functions during infection. Among these functions, NS1 was shown to be involved in the control of both viral and cellular translation; however, the mechanism by which this occurs remains to be determined. Thus, we have revisited the role of NS1 in translation by using a combination of influenza infection, mRNA reporter transfection, and in vitro functional and biochemical assays. Our data show that the NS1 protein is able to enhance the translation of virtually all tested mRNAs with the exception of constructs bearing the Dicistroviruses Internal ribosome entry segment (IRESes) (DCV and CrPV), suggesting a role at the level of translation initiation. The domain of NS1 required for translation stimulation was mapped to the RNA binding amino-terminal motif of the protein with residues R38 and K41 being critical for activity. Although we show that NS1 can bind directly to mRNAs, it does not correlate with its ability to stimulate translation. This activity rather relies on the property of NS1 to associate with ribosomes and to recruit them to target mRNAs.
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Affiliation(s)
- Baptiste Panthu
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France
| | - Olivier Terrier
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France; Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculté de médecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon, France
| | - Coralie Carron
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France; Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculté de médecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon, France
| | - Aurélien Traversier
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France; Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculté de médecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon, France
| | - Antoine Corbin
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France
| | - Laurent Balvay
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France
| | - Bruno Lina
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France; Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculté de médecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon, France
| | - Manuel Rosa-Calatrava
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France; Laboratoire de Virologie et Pathologie Humaine VirPath, Université Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculté de médecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon, France
| | - Théophile Ohlmann
- CIRI, International Center for Infectiology Research, Université de Lyon, 69364 Lyon, France; Inserm, U1111, 69364 Lyon, France; Ecole Normale Supérieure de Lyon, 69364 Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 69364 Lyon, France; CNRS, UMR5308, 69364 Lyon, France.
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278
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Habeck M. Bayesian Modeling of Biomolecular Assemblies with Cryo-EM Maps. Front Mol Biosci 2017; 4:15. [PMID: 28382301 PMCID: PMC5360716 DOI: 10.3389/fmolb.2017.00015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/07/2017] [Indexed: 01/09/2023] Open
Abstract
A growing array of experimental techniques allows us to characterize the three-dimensional structure of large biological assemblies at increasingly higher resolution. In addition to X-ray crystallography and nuclear magnetic resonance in solution, new structure determination methods such cryo-electron microscopy (cryo-EM), crosslinking/mass spectrometry and solid-state NMR have emerged. Often it is not sufficient to use a single experimental method, but complementary data need to be collected by using multiple techniques. The integration of all datasets can only be achieved by computational means. This article describes Inferential structure determination, a Bayesian approach to integrative modeling of biomolecular complexes with hybrid structural data. I will introduce probabilistic models for cryo-EM maps and outline Markov chain Monte Carlo algorithms for sampling model structures from the posterior distribution. I will focus on rigid and flexible modeling with cryo-EM data and discuss some of the computational challenges of Bayesian inference in the context of biomolecular modeling.
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Affiliation(s)
- Michael Habeck
- Statistical Inverse Problems in Biophysics, Max Planck Institute for Biophysical ChemistryGöttingen, Germany; Felix Bernstein Institute for Mathematical Statistics in the Biosciences, University of GöttingenGöttingen, Germany
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279
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Pfeffer S, Dudek J, Schaffer M, Ng BG, Albert S, Plitzko JM, Baumeister W, Zimmermann R, Freeze HH, Engel BD, Förster F. Dissecting the molecular organization of the translocon-associated protein complex. Nat Commun 2017; 8:14516. [PMID: 28218252 PMCID: PMC5321747 DOI: 10.1038/ncomms14516] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/05/2017] [Indexed: 12/26/2022] Open
Abstract
In eukaryotic cells, one-third of all proteins must be transported across or inserted into the endoplasmic reticulum (ER) membrane by the ER protein translocon. The translocon-associated protein (TRAP) complex is an integral component of the translocon, assisting the Sec61 protein-conducting channel by regulating signal sequence and transmembrane helix insertion in a substrate-dependent manner. Here we use cryo-electron tomography (CET) to study the structure of the native translocon in evolutionarily divergent organisms and disease-linked TRAP mutant fibroblasts from human patients. The structural differences detected by subtomogram analysis form a basis for dissecting the molecular organization of the TRAP complex. We assign positions to the four TRAP subunits within the complex, providing insights into their individual functions. The revealed molecular architecture of a central translocon component advances our understanding of membrane protein biogenesis and sheds light on the role of TRAP in human congenital disorders of glycosylation.
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Affiliation(s)
- Stefan Pfeffer
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Johanna Dudek
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Bobby G Ng
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Sahradha Albert
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Richard Zimmermann
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Hudson H Freeze
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Friedrich Förster
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.,Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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280
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Nielsen MH, Flygaard RK, Jenner LB. Structural analysis of ribosomal RACK1 and its role in translational control. Cell Signal 2017; 35:272-281. [PMID: 28161490 DOI: 10.1016/j.cellsig.2017.01.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 12/28/2022]
Abstract
Receptor for Activated C-Kinase 1 (RACK1) belongs to the WD40 family of proteins, known to act as scaffolding proteins in interaction networks. Accordingly, RACK1 is found to have numerous interacting partners ranging from kinases and signaling proteins to membrane bound receptors and ion channels. Interestingly, RACK1 has also been identified as a ribosomal protein present in all eukaryotic ribosomes. Structures of eukaryotic ribosomes have shown RACK1 to be located at the back of the head of the small ribosomal subunit. This suggests that RACK1 could act as a ribosomal scaffolding protein recruiting regulators of translation to the ribosome, and several studies have in fact found RACK1 to play a role in regulation of translation. To fully understand the role of RACK1 we need to understand whether the many reported interaction partners of RACK1 bind to free or ribosomal RACK1. In this review we provide a structural analysis of ribosome-bound RACK1 to provide a basis for answering this fundamental question. Our analysis shows that RACK1 is tightly bound to the ribosome through highly conserved and specific interactions confirming RACK1 as an integral ribosomal protein. Furthermore, we have analyzed whether reported binding sites for RACK1 interacting partners with a proposed role in translational control are accessible on ribosomal RACK1. Our analysis shows that most of the interaction partners with putative regulatory functions have binding sites that are available on ribosomal RACK1, supporting the role of RACK1 as a ribosomal signaling hub. We also discuss the possible role for RACK1 in recruitment of ribosomes to focal adhesion sites and regulation of local translation during cell spreading and migration.
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Affiliation(s)
- Maja Holch Nielsen
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
| | - Rasmus Kock Flygaard
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
| | - Lasse Bohl Jenner
- Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Aarhus University, Denmark
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281
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Khoshouei M, Pfeffer S, Baumeister W, Förster F, Danev R. Subtomogram analysis using the Volta phase plate. J Struct Biol 2017; 197:94-101. [DOI: 10.1016/j.jsb.2016.05.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/06/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
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282
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Crowther CV, Jones LE, Morelli JN, Mastrogiacomo EM, Porterfield C, Kent JL, Serra MJ. Influence of two bulge loops on the stability of RNA duplexes. RNA (NEW YORK, N.Y.) 2017; 23:217-228. [PMID: 27872162 PMCID: PMC5238796 DOI: 10.1261/rna.056168.116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 11/13/2016] [Indexed: 05/24/2023]
Abstract
Fifty-three RNA duplexes containing two single nucleotide bulge loops were optically melted in 1 M NaCl in order to determine the thermodynamic parameters ΔH°, ΔS°, ΔG°37, and TM for each duplex. Because of the large number of possible combinations and lack of sequence effects observed previously, we limited our initial investigation to adenosine bulges, the most common naturally occurring bulge. For example, the following duplexes were investigated: 5'GGCAXYAGGC/3'CCG YX CCG, 5'GGCAXY GCC/3'CCG YXACGG, and 5'GGC XYAGCC/3'CCGAYX CGG. The identity of XY (where XY are Watson-Crick base pairs) and the total number of base pairs in the terminal and central stems were varied. As observed for duplexes with a single bulge loop, the effect of the two bulge loops on duplex stability is primarily influenced by non-nearest neighbor interactions. In particular, the stability of the stems influences the destabilization of the duplex by the inserted bulge loops. The model proposed to predict the influence of multiple bulge loops on duplex stability suggests that the destabilization of each bulge is related to the stability of the adjacent stems. A database of RNA secondary structures was examined to determine the naturally occurring abundance of duplexes containing multiple bulge loops. Of the 2000 examples found in the database, over 65% of the two bulge loops occur within 3 base pairs of each other. A database of RNA three-dimensional structures was examined to determine the structure of duplexes containing two single nucleotide bulge loops. The structures of the bulge loops are described.
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Affiliation(s)
- Claire V Crowther
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
| | - Laura E Jones
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
| | - Jessica N Morelli
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
| | | | - Claire Porterfield
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
| | - Jessica L Kent
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
| | - Martin J Serra
- Department of Chemistry, Allegheny College, Meadville, Pennsylvania 16335, USA
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283
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Johnson MC, Ghalei H, Doxtader KA, Karbstein K, Stroupe ME. Structural Heterogeneity in Pre-40S Ribosomes. Structure 2017; 25:329-340. [PMID: 28111018 DOI: 10.1016/j.str.2016.12.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/07/2016] [Accepted: 12/21/2016] [Indexed: 11/24/2022]
Abstract
Late-stage 40S ribosome assembly is a highly regulated dynamic process that occurs in the cytoplasm, alongside the full translation machinery. Seven assembly factors (AFs) regulate and facilitate maturation, but the mechanisms through which they work remain undetermined. Here, we present a series of structures of the immature small subunit (pre-40S) determined by three-dimensional (3D) cryoelectron microscopy with 3D sorting to assess the molecule's heterogeneity. These structures demonstrate an extensive structural heterogeneity of interface AFs that likely regulates subunit joining during 40S maturation. We also present structural models for the beak and the platform, two regions where the low resolution of previous studies did not allow for localization of AFs and the rRNA, respectively. These models are supported by biochemical analyses using point variants and suggest that maturation of the 18S 3' end is regulated by dissociation of the AF Dim1 from the subunit interface, consistent with previous biochemical analyses.
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Affiliation(s)
- Matthew C Johnson
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA
| | - Homa Ghalei
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Katelyn A Doxtader
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Katrin Karbstein
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - M Elizabeth Stroupe
- Department of Biological Science, Institute of Molecular Biophysics, Florida State University, 91 Chieftain Way, Tallahassee, FL 32306, USA.
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284
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Khusainov I, Vicens Q, Bochler A, Grosse F, Myasnikov A, Ménétret JF, Chicher J, Marzi S, Romby P, Yusupova G, Yusupov M, Hashem Y. Structure of the 70S ribosome from human pathogen Staphylococcus aureus. Nucleic Acids Res 2016; 44:10491-10504. [PMID: 27906650 PMCID: PMC5137454 DOI: 10.1093/nar/gkw933] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/02/2016] [Accepted: 10/06/2016] [Indexed: 01/07/2023] Open
Abstract
Comparative structural studies of ribosomes from various organisms keep offering exciting insights on how species-specific or environment-related structural features of ribosomes may impact translation specificity and its regulation. Although the importance of such features may be less obvious within more closely related organisms, their existence could account for vital yet species-specific mechanisms of translation regulation that would involve stalling, cell survival and antibiotic resistance. Here, we present the first full 70S ribosome structure from Staphylococcus aureus, a Gram-positive pathogenic bacterium, solved by cryo-electron microscopy. Comparative analysis with other known bacterial ribosomes pinpoints several unique features specific to S. aureus around a conserved core, at both the protein and the RNA levels. Our work provides the structural basis for the many studies aiming at understanding translation regulation in S. aureus and for designing drugs against this often multi-resistant pathogen.
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Affiliation(s)
- Iskander Khusainov
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch 67400, France.,Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Russia
| | - Quentin Vicens
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Anthony Bochler
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - François Grosse
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Alexander Myasnikov
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch 67400, France
| | - Jean-François Ménétret
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch 67400, France
| | - Johana Chicher
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Stefano Marzi
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Pascale Romby
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Gulnara Yusupova
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch 67400, France
| | - Marat Yusupov
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch 67400, France
| | - Yaser Hashem
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
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285
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Zhang X, Lai M, Chang W, Yu I, Ding K, Mrazek J, Ng HL, Yang OO, Maslov DA, Zhou ZH. Structures and stabilization of kinetoplastid-specific split rRNAs revealed by comparing leishmanial and human ribosomes. Nat Commun 2016; 7:13223. [PMID: 27752045 PMCID: PMC5071889 DOI: 10.1038/ncomms13223] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/13/2016] [Indexed: 11/17/2022] Open
Abstract
The recent success in ribosome structure determination by cryoEM has opened the door to defining structural differences between ribosomes of pathogenic organisms and humans and to understand ribosome-targeting antibiotics. Here, by direct electron-counting cryoEM, we have determined the structures of the Leishmania donovani and human ribosomes at 2.9 Å and 3.6 Å, respectively. Our structure of the leishmanial ribosome elucidates the organization of the six fragments of its large subunit rRNA (as opposed to a single 28S rRNA in most eukaryotes, including humans) and reveals atomic details of a unique 20 amino acid extension of the uL13 protein that pins down the ends of three of the rRNA fragments. The structure also fashions many large rRNA expansion segments. Direct comparison of our human and leishmanial ribosome structures at the decoding A-site sheds light on how the bacterial ribosome-targeting drug paromomycin selectively inhibits the eukaryotic L. donovani, but not human, ribosome.
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Affiliation(s)
- Xing Zhang
- Center of Cryo Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- California NanoSystems Institute, University of California, Los Angeles, California 90095, USA
| | - Mason Lai
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Winston Chang
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Iris Yu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Ke Ding
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Jan Mrazek
- Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Hwee L. Ng
- Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Otto O. Yang
- California NanoSystems Institute, University of California, Los Angeles, California 90095, USA
- Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Dmitri A. Maslov
- Department of Biology, University of California, Riverside, California 91521, USA
| | - Z. Hong Zhou
- California NanoSystems Institute, University of California, Los Angeles, California 90095, USA
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA
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286
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Larburu N, Montellese C, O'Donohue MF, Kutay U, Gleizes PE, Plisson-Chastang C. Structure of a human pre-40S particle points to a role for RACK1 in the final steps of 18S rRNA processing. Nucleic Acids Res 2016; 44:8465-78. [PMID: 27530427 PMCID: PMC5041492 DOI: 10.1093/nar/gkw714] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 07/28/2016] [Accepted: 08/06/2016] [Indexed: 01/24/2023] Open
Abstract
Synthesis of ribosomal subunits in eukaryotes is a complex and tightly regulated process that has been mostly characterized in yeast. The discovery of a growing number of diseases linked to defects in ribosome biogenesis calls for a deeper understanding of these mechanisms and of the specificities of human ribosome maturation. We present the 19 Å resolution cryo-EM reconstruction of a cytoplasmic precursor to the human small ribosomal subunit, purified by using the tagged ribosome biogenesis factor LTV1 as bait. Compared to yeast pre-40S particles, this first three-dimensional structure of a human 40S subunit precursor shows noticeable differences with respect to the position of ribosome biogenesis factors and uncovers the early deposition of the ribosomal protein RACK1 during subunit maturation. Consistently, RACK1 is required for efficient processing of the 18S rRNA 3'-end, which might be related to its role in translation initiation. This first structural analysis of a human pre-ribosomal particle sets the grounds for high-resolution studies of conformational transitions accompanying ribosomal subunit maturation.
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MESH Headings
- Conserved Sequence
- Cryoelectron Microscopy
- Cytoplasm/metabolism
- GTP-Binding Proteins/metabolism
- HEK293 Cells
- HeLa Cells
- Humans
- Models, Molecular
- Neoplasm Proteins/metabolism
- Organelle Biogenesis
- Protein Binding
- RNA Processing, Post-Transcriptional/genetics
- RNA, Ribosomal, 18S/genetics
- Receptors for Activated C Kinase
- Receptors, Cell Surface/metabolism
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Small, Eukaryotic/chemistry
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- Natacha Larburu
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | | | - Marie-Françoise O'Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Ulrike Kutay
- Institut für Biochemie, ETH Zürich, CH-8093 Zurich, Switzerland
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Célia Plisson-Chastang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
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287
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Welty R, Hall KB. Nucleobases Undergo Dynamic Rearrangements during RNA Tertiary Folding. J Mol Biol 2016; 428:4490-4502. [PMID: 27693721 DOI: 10.1016/j.jmb.2016.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/31/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023]
Abstract
The tertiary structure of the GTPase center (GAC) of 23S ribosomal RNA (rRNA) as seen in cocrystals is extremely compact. It is stabilized by long-range hydrogen bonds and nucleobase stacking and by a triloop that forms within its three-way junction. Its folding pathway from secondary structure to tertiary structure has not been previously observed, but it was shown to require Mg2+ ions in equilibrium experiments. The fluorescent nucleotide 2-aminopurine was substituted at selected sites within the 60-nt GAC. Fluorescence intensity changes upon addition of MgCl2 were monitored over a time-course from 1ms to 100s as the RNA folds. The folding pathway is revealed here to be hierarchical through several intermediates. Observation of the nucleobases during folding provides a new perspective on the process and the pathway, revealing the dynamics of nucleobase conformational exchange during the folding transitions.
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Affiliation(s)
- Robb Welty
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Kathleen B Hall
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
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288
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Subramaniam S, Earl LA, Falconieri V, Milne JL, Egelman EH. Resolution advances in cryo-EM enable application to drug discovery. Curr Opin Struct Biol 2016; 41:194-202. [PMID: 27552081 DOI: 10.1016/j.sbi.2016.07.009] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 12/23/2022]
Abstract
The prospect that the structures of protein assemblies, small and large, can be determined using cryo-electron microscopy (cryo-EM) is beginning to transform the landscape of structural biology and cell biology. Great progress is being made in determining 3D structures of biological assemblies ranging from icosahedral viruses and helical arrays to small membrane proteins and protein complexes. Here, we review recent advances in this field, focusing especially on the emerging use of cryo-EM in mapping the binding of drugs and inhibitors to protein targets, an application that requires structure determination at the highest possible resolutions. We discuss methods used to evaluate the information contained in cryo-EM density maps and consider strengths and weaknesses of approaches currently used to measure map resolution.
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Affiliation(s)
- Sriram Subramaniam
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Lesley A Earl
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Veronica Falconieri
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jacqueline Ls Milne
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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289
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Mekdad HE, Boutant E, Karnib H, Biedma ME, Sharma KK, Malytska I, Laumond G, Roy M, Réal E, Paillart JC, Moog C, Darlix JL, Mély Y, de Rocquigny H. Characterization of the interaction between the HIV-1 Gag structural polyprotein and the cellular ribosomal protein L7 and its implication in viral nucleic acid remodeling. Retrovirology 2016; 13:54. [PMID: 27515235 PMCID: PMC4982112 DOI: 10.1186/s12977-016-0287-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/27/2016] [Indexed: 12/12/2022] Open
Abstract
Background In HIV-1 infected cells, the integrated viral DNA is transcribed by the host cell machinery to generate the full length HIV-1 RNA (FL RNA) that serves as mRNA encoding for the Gag and GagPol precursors. Virion formation is orchestrated by Gag, and the current view is that a specific interaction between newly made Gag molecules and FL RNA initiates the process. This in turn would cause FL RNA dimerization by the NC domain of Gag (GagNC). However the RNA chaperoning activity of unprocessed Gag is low as compared to the mature NC protein. This prompted us to search for GagNC co-factors. Results Here we report that RPL7, a major ribosomal protein involved in translation regulation, is a partner of Gag via its interaction with the NC domain. This interaction is mediated by the NC zinc fingers and the N- and C-termini of RPL7, respectively, but seems independent of RNA binding, Gag oligomerization and its interaction with the plasma membrane. Interestingly, RPL7 is shown for the first time to exhibit a potent DNA/RNA chaperone activity higher than that of Gag. In addition, Gag and RPL7 can function in concert to drive rapid nucleic acid hybridization. Conclusions Our results show that GagNC interacts with the ribosomal protein RPL7 endowed with nucleic acid chaperone activity, favoring the notion that RPL7 could be a Gag helper chaperoning factor possibly contributing to the start of Gag assembly. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0287-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hala El Mekdad
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Emmanuel Boutant
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Hassan Karnib
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Marina E Biedma
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1109, Université de Strasbourg, 3 rue Koeberlé, 67000, Strasbourg Cedex, France
| | - Kamal Kant Sharma
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Iuliia Malytska
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Géraldine Laumond
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1109, Université de Strasbourg, 3 rue Koeberlé, 67000, Strasbourg Cedex, France
| | - Marion Roy
- Architecture et Réactivité de l'ARN, CNRS, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15 rue René Descartes, 67084, Strasbourg Cedex, France
| | - Eléonore Réal
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Jean-Christophe Paillart
- Architecture et Réactivité de l'ARN, CNRS, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15 rue René Descartes, 67084, Strasbourg Cedex, France
| | - Christiane Moog
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1109, Université de Strasbourg, 3 rue Koeberlé, 67000, Strasbourg Cedex, France
| | - Jean Luc Darlix
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France
| | - Hugues de Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch Cedex, France.
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290
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Francisco-Velilla R, Fernandez-Chamorro J, Ramajo J, Martinez-Salas E. The RNA-binding protein Gemin5 binds directly to the ribosome and regulates global translation. Nucleic Acids Res 2016; 44:8335-51. [PMID: 27507887 PMCID: PMC5041490 DOI: 10.1093/nar/gkw702] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/31/2016] [Indexed: 12/21/2022] Open
Abstract
RNA-binding proteins (RBPs) play crucial roles in all organisms. The protein Gemin5 harbors two functional domains. The N-terminal domain binds to snRNAs targeting them for snRNPs assembly, while the C-terminal domain binds to IRES elements through a non-canonical RNA-binding site. Here we report a comprehensive view of the Gemin5 interactome; most partners copurified with the N-terminal domain via RNA bridges. Notably, Gemin5 sediments with the subcellular ribosome fraction, and His-Gemin5 binds to ribosome particles via its N-terminal domain. The interaction with the ribosome was lost in F381A and Y474A Gemin5 mutants, but not in W14A and Y15A. Moreover, the ribosomal proteins L3 and L4 bind directly with Gemin5, and conversely, Gemin5 mutants impairing the binding to the ribosome are defective in the interaction with L3 and L4. The overall polysome profile was affected by Gemin5 depletion or overexpression, concomitant to an increase or a decrease, respectively, of global protein synthesis. Gemin5, and G5-Nter as well, were detected on the polysome fractions. These results reveal the ribosome-binding capacity of the N-ter moiety, enabling Gemin5 to control global protein synthesis. Our study uncovers a crosstalk between this protein and the ribosome, and provides support for the view that Gemin5 may control translation elongation.
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Affiliation(s)
| | | | - Jorge Ramajo
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolás Cabrera 1, 28049-Madrid, Spain
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291
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Ramesh M, Woolford JL. Eukaryote-specific rRNA expansion segments function in ribosome biogenesis. RNA (NEW YORK, N.Y.) 2016; 22:1153-1162. [PMID: 27317789 PMCID: PMC4931108 DOI: 10.1261/rna.056705.116] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/09/2016] [Indexed: 05/30/2023]
Abstract
The secondary structure of ribosomal RNA (rRNA) is largely conserved across all kingdoms of life. However, eukaryotes have evolved extra blocks of rRNA sequences, relative to those of prokaryotes, called expansion segments (ES). A thorough characterization of the potential roles of ES remains to be done, possibly because of limitations in the availability of robust systems to study rRNA mutants. We sought to systematically investigate the potential functions, if any, of the ES in 25S rRNA of Saccharomyces cerevisiae by deletion mutagenesis. We deleted 14 of the 16 different eukaryote-specific ES in yeast 25S rRNA individually and assayed their phenotypes. Our results show that all but two of the ES tested are necessary for optimal growth and are required for production of 25S rRNA, suggesting that ES play roles in ribosome biogenesis. Further, we classified expansion segments into groups that participate in early nucleolar, middle, and late nucleoplasmic steps of ribosome biogenesis, by assaying their pre-rRNA processing phenotypes. This study is the first of its kind to systematically identify the functions of eukaryote-specific expansion segments by showing that they play roles in specific steps of ribosome biogenesis. The catalog of phenotypes we identified, combined with previous investigations of the roles ribosomal proteins in large subunit biogenesis, leads us to infer that assembling ribosomes are composed of distinct RNA and protein structural neighborhood clusters that participate in specific steps of ribosome biogenesis.
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Affiliation(s)
- Madhumitha Ramesh
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15232, USA
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15232, USA
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292
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van Zundert G, Bonvin A. Defining the limits and reliability of rigid-body fitting in cryo-EM maps using multi-scale image pyramids. J Struct Biol 2016; 195:252-258. [DOI: 10.1016/j.jsb.2016.06.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 05/27/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
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293
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Pánek J, Kolář M, Herrmannová A, Valášek LS. A systematic computational analysis of the rRNA-3' UTR sequence complementarity suggests a regulatory mechanism influencing post-termination events in metazoan translation. RNA (NEW YORK, N.Y.) 2016; 22:957-967. [PMID: 27190231 PMCID: PMC4911919 DOI: 10.1261/rna.056119.116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 04/17/2016] [Indexed: 06/05/2023]
Abstract
Nucleic acid sequence complementarity underlies many fundamental biological processes. Although first noticed a long time ago, sequence complementarity between mRNAs and ribosomal RNAs still lacks a meaningful biological interpretation. Here we used statistical analysis of large-scale sequence data sets and high-throughput computing to explore complementarity between 18S and 28S rRNAs and mRNA 3' UTR sequences. By the analysis of 27,646 full-length 3' UTR sequences from 14 species covering both protozoans and metazoans, we show that the computed 18S rRNA complementarity creates an evolutionarily conserved localization pattern centered around the ribosomal mRNA entry channel, suggesting its biological relevance and functionality. Based on this specific pattern and earlier data showing that post-termination 80S ribosomes are not stably anchored at the stop codon and can migrate in both directions to codons that are cognate to the P-site deacylated tRNA, we propose that the 18S rRNA-mRNA complementarity selectively stabilizes post-termination ribosomal complexes to facilitate ribosome recycling. We thus demonstrate that the complementarity between 18S rRNA and 3' UTRs has a non-random nature and very likely carries information with a regulatory potential for translational control.
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Affiliation(s)
- Josef Pánek
- Laboratory of Bioinformatics, Institute of Microbiology of the Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Michal Kolář
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
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294
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Nicolas E, Parisot P, Pinto-Monteiro C, de Walque R, De Vleeschouwer C, Lafontaine DLJ. Involvement of human ribosomal proteins in nucleolar structure and p53-dependent nucleolar stress. Nat Commun 2016; 7:11390. [PMID: 27265389 PMCID: PMC4897761 DOI: 10.1038/ncomms11390] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/21/2016] [Indexed: 02/07/2023] Open
Abstract
The nucleolus is a potent disease biomarker and a target in cancer therapy. Ribosome biogenesis is initiated in the nucleolus where most ribosomal (r-) proteins assemble onto precursor rRNAs. Here we systematically investigate how depletion of each of the 80 human r-proteins affects nucleolar structure, pre-rRNA processing, mature rRNA accumulation and p53 steady-state level. We developed an image-processing programme for qualitative and quantitative discrimination of normal from altered nucleolar morphology. Remarkably, we find that uL5 (formerly RPL11) and uL18 (RPL5) are the strongest contributors to nucleolar integrity. Together with the 5S rRNA, they form the late-assembling central protuberance on mature 60S subunits, and act as an Hdm2 trap and p53 stabilizer. Other major contributors to p53 homeostasis are also strictly late-assembling large subunit r-proteins essential to nucleolar structure. The identification of the r-proteins that specifically contribute to maintaining nucleolar structure and p53 steady-state level provides insights into fundamental aspects of cell and cancer biology. The nucleolus is a specialized functional domain of the nucleus where ribosome biogenesis is initiated and also implicated in a p53-dependent anti-tumor surveillance. Here the authors use a quantitative imaging approach to detail the role of each ribosomal protein on the structural integrity of the nucleolus and p53 homeostasis.
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Affiliation(s)
- Emilien Nicolas
- RNA Molecular Biology, F.R.S./FNRS, Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium.,Center for Microscopy and Molecular Imaging, B-6041 Charleroi-Gosselies, Belgium
| | - Pascaline Parisot
- ICTEAM-ELEN, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Celina Pinto-Monteiro
- RNA Molecular Biology, F.R.S./FNRS, Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Roxane de Walque
- RNA Molecular Biology, F.R.S./FNRS, Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | | | - Denis L J Lafontaine
- RNA Molecular Biology, F.R.S./FNRS, Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium.,Center for Microscopy and Molecular Imaging, B-6041 Charleroi-Gosselies, Belgium
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295
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Sharma E, Sterne-Weiler T, O'Hanlon D, Blencowe BJ. Global Mapping of Human RNA-RNA Interactions. Mol Cell 2016; 62:618-26. [PMID: 27184080 DOI: 10.1016/j.molcel.2016.04.030] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/01/2016] [Accepted: 04/25/2016] [Indexed: 11/27/2022]
Abstract
The majority of the human genome is transcribed into non-coding (nc)RNAs that lack known biological functions or else are only partially characterized. Numerous characterized ncRNAs function via base pairing with target RNA sequences to direct their biological activities, which include critical roles in RNA processing, modification, turnover, and translation. To define roles for ncRNAs, we have developed a method enabling the global-scale mapping of RNA-RNA duplexes crosslinked in vivo, "LIGation of interacting RNA followed by high-throughput sequencing" (LIGR-seq). Applying this method in human cells reveals a remarkable landscape of RNA-RNA interactions involving all major classes of ncRNA and mRNA. LIGR-seq data reveal unexpected interactions between small nucleolar (sno)RNAs and mRNAs, including those involving the orphan C/D box snoRNA, SNORD83B, that control steady-state levels of its target mRNAs. LIGR-seq thus represents a powerful approach for illuminating the functions of the myriad of uncharacterized RNAs that act via base-pairing interactions.
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Affiliation(s)
- Eesha Sharma
- Donnelly Centre, University of Toronto, Toronto, ON M53 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M53 3E1, Canada
| | | | - Dave O'Hanlon
- Donnelly Centre, University of Toronto, Toronto, ON M53 3E1, Canada
| | - Benjamin J Blencowe
- Donnelly Centre, University of Toronto, Toronto, ON M53 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M53 3E1, Canada.
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296
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Veit G, Oliver K, Apaja PM, Perdomo D, Bidaud-Meynard A, Lin ST, Guo J, Icyuz M, Sorscher EJ, Hartman JL, Lukacs GL. Ribosomal Stalk Protein Silencing Partially Corrects the ΔF508-CFTR Functional Expression Defect. PLoS Biol 2016; 14:e1002462. [PMID: 27168400 PMCID: PMC4864299 DOI: 10.1371/journal.pbio.1002462] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/14/2016] [Indexed: 01/05/2023] Open
Abstract
The most common cystic fibrosis (CF) causing mutation, deletion of phenylalanine 508 (ΔF508 or Phe508del), results in functional expression defect of the CF transmembrane conductance regulator (CFTR) at the apical plasma membrane (PM) of secretory epithelia, which is attributed to the degradation of the misfolded channel at the endoplasmic reticulum (ER). Deletion of phenylalanine 670 (ΔF670) in the yeast oligomycin resistance 1 gene (YOR1, an ABC transporter) of Saccharomyces cerevisiae phenocopies the ΔF508-CFTR folding and trafficking defects. Genome-wide phenotypic (phenomic) analysis of the Yor1-ΔF670 biogenesis identified several modifier genes of mRNA processing and translation, which conferred oligomycin resistance to yeast. Silencing of orthologues of these candidate genes enhanced the ΔF508-CFTR functional expression at the apical PM in human CF bronchial epithelia. Although knockdown of RPL12, a component of the ribosomal stalk, attenuated the translational elongation rate, it increased the folding efficiency as well as the conformational stability of the ΔF508-CFTR, manifesting in 3-fold augmented PM density and function of the mutant. Combination of RPL12 knockdown with the corrector drug, VX-809 (lumacaftor) restored the mutant function to ~50% of the wild-type channel in primary CFTRΔF508/ΔF508 human bronchial epithelia. These results and the observation that silencing of other ribosomal stalk proteins partially rescue the loss-of-function phenotype of ΔF508-CFTR suggest that the ribosomal stalk modulates the folding efficiency of the mutant and is a potential therapeutic target for correction of the ΔF508-CFTR folding defect. Reducing the rate of translational elongation by silencing ribosomal stalk proteins ameliorates the folding and stability defect of the cystic fibrosis mutant protein ΔF508-CFTR, partially restoring the plasma membrane chloride conductance. Cystic fibrosis (CF) is one of the most common autosomal recessive diseases in Caucasians. It is caused by mutations in the CF transmembrane conductance regulator (CFTR), which functions as an anion channel at the apical plasma membrane of secretory epithelia. The most common CF mutation, a deletion of the phenylalanine residue at position 508 (ΔF508), results in the channel misfolding and subsequent intracellular degradation. Our previous genome-wide phenotypic screens, using a yeast variant, have predicted modifier genes for ΔF508-CFTR biogenesis. Here, we show that silencing of one of these candidate genes, RPL12, a component of the ribosomal stalk, increased the folding and stabilization of ΔF508-CFTR, resulting in its increased plasma membrane expression and function. Our data suggest that reducing the translational elongation rate via RPL12 silencing can partially reverse the ΔF508-CFTR folding defect. Importantly, RPL12 silencing in combination with the corrector drug VX-809 (lumacaftor), increased the mutant function to 50% of the wild-type CFTR channel, suggesting that the ribosomal stalk perturbation may represent a therapeutic target for rescuing the ΔF508-CFTR biogenesis defect.
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Affiliation(s)
- Guido Veit
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| | - Kathryn Oliver
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Pirjo M. Apaja
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| | - Doranda Perdomo
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| | | | - Sheng-Ting Lin
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| | - Jingyu Guo
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Mert Icyuz
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Eric J. Sorscher
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - John L. Hartman
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail: (JLH); (GLL)
| | - Gergely L. Lukacs
- Department of Physiology, McGill University, Montréal, Quebec, Canada
- Department of Biochemistry, McGill University, Montréal, Quebec, Canada
- Groupe de Recherche Axé sur la Structure des Protéines (GRASP), McGill University, Montréal, Quebec, Canada
- * E-mail: (JLH); (GLL)
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297
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Murray J, Savva CG, Shin BS, Dever TE, Ramakrishnan V, Fernández IS. Structural characterization of ribosome recruitment and translocation by type IV IRES. eLife 2016; 5. [PMID: 27159451 PMCID: PMC4861600 DOI: 10.7554/elife.13567] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 04/04/2016] [Indexed: 12/20/2022] Open
Abstract
Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts the otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation. DOI:http://dx.doi.org/10.7554/eLife.13567.001
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Affiliation(s)
- Jason Murray
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.,Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | | | - Byung-Sik Shin
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Thomas E Dever
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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298
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Waku T, Nakajima Y, Yokoyama W, Nomura N, Kako K, Kobayashi A, Shimizu T, Fukamizu A. NML-mediated rRNA base methylation links ribosomal subunit formation to cell proliferation in a p53-dependent manner. J Cell Sci 2016; 129:2382-93. [PMID: 27149924 DOI: 10.1242/jcs.183723] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/29/2016] [Indexed: 12/25/2022] Open
Abstract
Ribosomal RNAs (rRNAs) act as scaffolds and ribozymes in ribosomes, and these functions are modulated by post-transcriptional modifications. However, the biological role of base methylation, a well-conserved modification of rRNA, is poorly understood. Here, we demonstrate that a nucleolar factor, nucleomethylin (NML; also known as RRP8), is required for the N(1)-methyladenosine (m(1)A) modification in 28S rRNAs of human and mouse cells. NML also contributes to 60S ribosomal subunit formation. Intriguingly, NML depletion increases 60S ribosomal protein L11 (RPL11) levels in the ribosome-free fraction and protein levels of p53 through an RPL11-MDM2 complex, which activates the p53 pathway. Consequently, the growth of NML-depleted cells is suppressed in a p53-dependent manner. These observations reveal a new biological function of rRNA base methylation, which links ribosomal subunit formation to p53-dependent inhibition of cell proliferation in mammalian cells.
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Affiliation(s)
- Tsuyoshi Waku
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuka Nakajima
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Wataru Yokoyama
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Naoto Nomura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Koichiro Kako
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Akira Kobayashi
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akiyoshi Fukamizu
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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Aw J, Shen Y, Wilm A, Sun M, Lim X, Boon KL, Tapsin S, Chan YS, Tan CP, Sim A, Zhang T, Susanto T, Fu Z, Nagarajan N, Wan Y. In Vivo Mapping of Eukaryotic RNA Interactomes Reveals Principles of Higher-Order Organization and Regulation. Mol Cell 2016; 62:603-17. [DOI: 10.1016/j.molcel.2016.04.028] [Citation(s) in RCA: 226] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/07/2016] [Accepted: 04/22/2016] [Indexed: 01/01/2023]
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Zinoviev A, Hellen CUT, Pestova TV. Multiple mechanisms of reinitiation on bicistronic calicivirus mRNAs. Mol Cell 2016; 57:1059-1073. [PMID: 25794616 DOI: 10.1016/j.molcel.2015.01.039] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 12/31/2014] [Accepted: 01/26/2015] [Indexed: 02/05/2023]
Abstract
Reinitiation is a strategy used by viruses to express several cistrons from one mRNA. Although extremely weak after translation of long open reading frames (ORFs) on cellular mRNAs, reinitiation occurs efficiently on subgenomic bicistronic calicivirus mRNAs, enabling synthesis of minor capsid proteins. The process is governed by a short element upstream of the restart AUG, designated "termination upstream ribosomal binding site" (TURBS). It contains the conserved Motif 1 complementary to h26 of 18S rRNA, displayed in the loop of a hairpin formed by species-specific Motifs 2/2(∗). To determine the advantages conferred on reinitiation by TURBS, we reconstituted this process in vitro on two model bicistronic calicivirus mRNAs. We found that post-termination ribosomal tethering of mRNA by TURBS allows reinitiation by post-termination 80S ribosomes and diminishes dependence on eukaryotic initiation factor 3 (eIF3) of reinitiation by recycled 40S subunits, which can be mediated either by eIFs 2/1/1A or by Ligatin following ABCE1-dependent or -independent splitting of post-termination complexes.
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Affiliation(s)
- Alexandra Zinoviev
- Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - Christopher U T Hellen
- Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - Tatyana V Pestova
- Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
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