1
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Cruz VE, Weirich CS, Peddada N, Erzberger JP. The DEAD-box ATPase Dbp10/DDX54 initiates peptidyl transferase center formation during 60S ribosome biogenesis. Nat Commun 2024; 15:3296. [PMID: 38632236 PMCID: PMC11024185 DOI: 10.1038/s41467-024-47616-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
DEAD-box ATPases play crucial roles in guiding rRNA restructuring events during the biogenesis of large (60S) ribosomal subunits, but their precise molecular functions are currently unknown. In this study, we present cryo-EM reconstructions of nucleolar pre-60S intermediates that reveal an unexpected, alternate secondary structure within the nascent peptidyl-transferase-center (PTC). Our analysis of three sequential nucleolar pre-60S intermediates reveals that the DEAD-box ATPase Dbp10/DDX54 remodels this alternate base pairing and enables the formation of the rRNA junction that anchors the mature form of the universally conserved PTC A-loop. Post-catalysis, Dbp10 captures rRNA helix H61, initiating the concerted exchange of biogenesis factors during late nucleolar 60S maturation. Our findings show that Dbp10 activity is essential for the formation of the ribosome active site and reveal how this function is integrated with subsequent assembly steps to drive the biogenesis of the large ribosomal subunit.
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Affiliation(s)
- Victor E Cruz
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
- O'Donnell Brain Institute/CAND, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Christine S Weirich
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Nagesh Peddada
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
- Center for the Genetics of Host Defense, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Jan P Erzberger
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
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2
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Mitterer V, Hamze H, Kunowska N, Stelzl U, Henras A, Hurt E. The RNA helicase Dbp10 coordinates assembly factor association with PTC maturation during ribosome biogenesis. Nucleic Acids Res 2024; 52:1975-1987. [PMID: 38113283 PMCID: PMC10899779 DOI: 10.1093/nar/gkad1206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 11/08/2023] [Accepted: 12/11/2023] [Indexed: 12/21/2023] Open
Abstract
During ribosome biogenesis a plethora of assembly factors and essential enzymes drive the unidirectional maturation of nascent pre-ribosomal subunits. The DEAD-box RNA helicase Dbp10 is suggested to restructure pre-ribosomal rRNA of the evolving peptidyl-transferase center (PTC) on nucleolar ribosomal 60S assembly intermediates. Here, we show that point mutations within conserved catalytic helicase-core motifs of Dbp10 yield a dominant-lethal growth phenotype. Such dbp10 mutants, which stably associate with pre-60S intermediates, impair pre-60S biogenesis at a nucleolar stage prior to the release of assembly factor Rrp14 and stable integration of late nucleolar factors such as Noc3. Furthermore, the binding of the GTPase Nug1 to particles isolated directly via mutant Dbp10 bait proteins is specifically inhibited. The N-terminal domain of Nug1 interacts with Dbp10 and the methyltransferase Spb1, whose pre-60S incorporation is also reduced in absence of functional Dbp10 resulting in decreased methylation of 25S rRNA nucleotide G2922. Our data suggest that Dbp10's helicase activity generates the necessary framework for assembly factor docking thereby permitting PTC rRNA methylation and the progression of pre-60S maturation.
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Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Hussein Hamze
- Molecular, Cellular and Developmental Biology Unit (MCD), Center for Integrative Biology (CBI), CNRS, University of Toulouse, 31062 Toulouse, France
| | - Natalia Kunowska
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, 8010 Graz, Austria
| | - Ulrich Stelzl
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Center for Integrative Biology (CBI), CNRS, University of Toulouse, 31062 Toulouse, France
| | - Ed Hurt
- Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany
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3
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Deryabin A, Moraleva A, Dobrochaeva K, Kovaleva D, Rubtsova M, Dontsova O, Rubtsov Y. Human RPF1 and ESF1 in Pre-rRNA Processing and the Assembly of Pre-Ribosomal Particles: A Functional Study. Cells 2024; 13:326. [PMID: 38391939 PMCID: PMC10886481 DOI: 10.3390/cells13040326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
Ribosome biogenesis is essential for the functioning of living cells. In higher eukaryotes, this multistep process is tightly controlled and involves a variety of specialized proteins and RNAs. This pool of so-called ribosome biogenesis factors includes diverse proteins with enzymatic and structural functions. Some of them have homologs in yeast S. cerevisiae, and their function can be inferred from the structural and biochemical data obtained for the yeast counterparts. The functions of human proteins RPF1 and ESF1 remain largely unclear, although RPF1 has been recently shown to participate in 60S biogenesis. Both proteins have drawn our attention since they contribute to the early stages of ribosome biogenesis, which are far less studied than the later stages. In this study, we employed the loss-of-function shRNA/siRNA-based approach to the human cell line HEK293 to determine the role of RPF1 and ESF1 in ribosome biogenesis. Downregulating RPF1 and ESF1 significantly changed the pattern of RNA products derived from 47S pre-rRNA. Our findings demonstrate that RPF1 and ESF1 are associated with different pre-ribosomal particles, pre-60S, and pre-40S particles, respectively. Our results allow for speculation about the particular steps of pre-rRNA processing, which highly rely on the RPF1 and ESF1 functions. We suggest that both factors are not directly involved in pre-rRNA cleavage but rather help pre-rRNA to acquire the conformation favoring its cleavage.
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Affiliation(s)
- Alexander Deryabin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Anastasiia Moraleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- Department of Applied Mathematics, MIREA-Russian Technological University, 119454 Moscow, Russia
| | - Kira Dobrochaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Diana Kovaleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
| | - Maria Rubtsova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Olga Dontsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Yury Rubtsov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 119997 Moscow, Russia
- N.N.Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, 115478 Moscow, Russia
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4
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Ma B, Liu H, Xiu ZH, Yang HH, Wang H, Wang Y, Tan BC. Defective kernel 58 encodes an Rrp15p domain-containing protein essential to ribosome biogenesis and seed development in maize. THE NEW PHYTOLOGIST 2024; 241:1662-1675. [PMID: 38058237 DOI: 10.1111/nph.19460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 11/08/2023] [Indexed: 12/08/2023]
Abstract
Ribosome biogenesis is a highly dynamic and orchestrated process facilitated by hundreds of ribosomal biogenesis factors and small nucleolar RNAs. While many of the advances are derived from studies in yeast, ribosome biogenesis remains largely unknown in plants despite its importance to plant growth and development. Through characterizing the maize (Zea mays) defective kernel and embryo-lethal mutant dek58, we show that DEK58 encodes an Rrp15p domain-containing protein with 15.3% identity to yeast Rrp15. Over-expression of DEK58 rescues the mutant phenotype. DEK58 is localized in the nucleolus. Ribosome profiling and RNA gel blot analyses show that the absence of DEK58 reduces ribosome assembly and impedes pre-rRNA processing, accompanied by the accumulation of nearly all the pre-rRNA processing intermediates and the production of an aberrant processing product P-25S*. DEK58 interacts with ZmSSF1, a maize homolog of the yeast Ssf1 in the 60S processome. DEK58 and ZmSSF1 interact with ZmCK2α, a putative component of the yeast UTP-C complex involved in the small ribosomal subunit processome. These results demonstrate that DEK58 is essential to seed development in maize. It functions in the early stage of pre-rRNA processing in ribosome biogenesis, possibly through interacting with ZmSSF1 and ZmCK2α in maize.
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Affiliation(s)
- Bing Ma
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Hui Liu
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Zhi-Hui Xiu
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Huan-Huan Yang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Hongqiu Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yong Wang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Bao-Cai Tan
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
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5
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Thoms M, Lau B, Cheng J, Fromm L, Denk T, Kellner N, Flemming D, Fischer P, Falquet L, Berninghausen O, Beckmann R, Hurt E. Structural insights into coordinating 5S RNP rotation with ITS2 pre-RNA processing during ribosome formation. EMBO Rep 2023; 24:e57984. [PMID: 37921038 DOI: 10.15252/embr.202357984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 10/11/2023] [Accepted: 10/14/2023] [Indexed: 11/04/2023] Open
Abstract
The rixosome defined in Schizosaccharomyces pombe and humans performs diverse roles in pre-ribosomal RNA processing and gene silencing. Here, we isolate and describe the conserved rixosome from Chaetomium thermophilum, which consists of two sub-modules, the sphere-like Rix1-Ipi3-Ipi1 and the butterfly-like Las1-Grc3 complex, connected by a flexible linker. The Rix1 complex of the rixosome utilizes Sda1 as landing platform on nucleoplasmic pre-60S particles to wedge between the 5S rRNA tip and L1-stalk, thereby facilitating the 180° rotation of the immature 5S RNP towards its mature conformation. Upon rixosome positioning, the other sub-module with Las1 endonuclease and Grc3 polynucleotide-kinase can reach a strategic position at the pre-60S foot to cleave and 5' phosphorylate the nearby ITS2 pre-rRNA. Finally, inward movement of the L1 stalk permits the flexible Nop53 N-terminus with its AIM motif to become positioned at the base of the L1-stalk to facilitate Mtr4 helicase-exosome participation for completing ITS2 removal. Thus, the rixosome structure elucidates the coordination of two central ribosome biogenesis events, but its role in gene silencing may adapt similar strategies.
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Affiliation(s)
- Matthias Thoms
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Benjamin Lau
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Jingdong Cheng
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai, China
| | - Lisa Fromm
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Timo Denk
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nikola Kellner
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Paulina Fischer
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Laurent Falquet
- University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | | | - Roland Beckmann
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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6
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LaPeruta AJ, Micic J, Woolford Jr. JL. Additional principles that govern the release of pre-ribosomes from the nucleolus into the nucleoplasm in yeast. Nucleic Acids Res 2023; 51:10867-10883. [PMID: 35736211 PMCID: PMC10639060 DOI: 10.1093/nar/gkac430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 05/05/2022] [Accepted: 06/20/2022] [Indexed: 11/14/2022] Open
Abstract
During eukaryotic ribosome biogenesis, pre-ribosomes travel from the nucleolus, where assembly is initiated, to the nucleoplasm and then are exported to the cytoplasm, where assembly concludes. Although nuclear export of pre-ribosomes has been extensively investigated, the release of pre-ribosomes from the nucleolus is an understudied phenomenon. Initial data indicate that unfolded rRNA interacts in trans with nucleolar components and that, when rRNA folds due to ribosomal protein (RP) binding, the number of trans interactions drops below the threshold necessary for nucleolar retention. To validate and expand on this idea, we performed a bioinformatic analysis of the protein components of the Saccharomyces cerevisiae ribosome assembly pathway. We found that ribosome biogenesis factors (RiBi factors) contain significantly more predicted trans interacting regions than RPs. We also analyzed cryo-EM structures of ribosome assembly intermediates to determine how nucleolar pre-ribosomes differ from post-nucleolar pre-ribosomes, specifically the capacity of RPs, RiBi factors, and rRNA components to interact in trans. We observed a significant decrease in the theoretical trans-interacting capability of pre-ribosomes between nucleolar and post-nucleolar stages of assembly due to the release of RiBi factors from particles and the folding of rRNA. Here, we provide a mechanism for the release of pre-ribosomes from the nucleolus.
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Affiliation(s)
- Amber J LaPeruta
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - John L Woolford Jr.
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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7
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LaPeruta AJ, Hedayati S, Micic J, Fitzgerald F, Kim D, Oualline G, Woolford JL. Yeast ribosome biogenesis factors Puf6 and Nog2 and ribosomal proteins uL2 and eL43 act in concert to facilitate the release of nascent large ribosomal subunits from the nucleolus. Nucleic Acids Res 2023; 51:11277-11290. [PMID: 37811893 PMCID: PMC10639061 DOI: 10.1093/nar/gkad794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 09/11/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
Large ribosomal subunit precursors (pre-LSUs) are primarily synthesized in the nucleolus. At an undetermined step in their assembly, they are released into the nucleoplasm. Structural models of yeast pre-LSUs at various stages of assembly have been collected using cryo-EM. However, which cryo-EM model is closest to the final nucleolar intermediate of the LSU has yet to be determined. To elucidate the mechanisms of the release of pre-LSUs from the nucleolus, we assayed effects of depleting or knocking out two yeast ribosome biogenesis factors (RiBi factors), Puf6 and Nog2, and two ribosomal proteins, uL2 and eL43. These proteins function during or stabilize onto pre-LSUs between the late nucleolar stages to early nucleoplasmic stages of ribosome biogenesis. By characterizing the phenotype of these four mutants, we determined that a particle that is intermediate between the cryo-EM model State NE1 and State NE2 likely represents the final nucleolar assembly intermediate of the LSU. We conclude that the release of the RiBi factors Nip7, Nop2 and Spb1 and the subsequent stabilization of rRNA domains IV and V may be key triggers for the release of pre-LSUs from the nucleolus.
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Affiliation(s)
- Amber J LaPeruta
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Stefanie Hedayati
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Fiona Fitzgerald
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - David Kim
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Grace Oualline
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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8
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Cruz VE, Weirich CS, Peddada N, Erzberger JP. The DEAD-box ATPase Dbp10/DDX54 initiates peptidyl transferase center formation during 60S ribosome biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.01.565222. [PMID: 37961218 PMCID: PMC10635065 DOI: 10.1101/2023.11.01.565222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
DEAD-box ATPases play crucial roles in guiding rRNA restructuring events during the biogenesis of large (60S) ribosomal subunits, but their precise molecular functions are currently unknown. In this study, we present cryo-EM reconstructions of nucleolar pre-60S intermediates that reveal an unexpected, alternate secondary structure within the nascent peptidyl-transferase-center (PTC). Our analysis of three sequential nucleolar pre-60S intermediates reveals that the DEAD-box ATPase Dbp10/DDX54 remodels this alternate base pairing and enables the formation of the rRNA junction that anchors the mature form of the universally conserved PTC A-loop. Post-catalysis, Dbp10 captures rRNA helix H61, initiating the concerted exchange of biogenesis factors during late nucleolar 60S maturation. Our findings show that Dbp10 activity is essential for the formation of the ribosome active site and reveal how this function is integrated with subsequent assembly steps to drive the biogenesis of the large ribosomal subunit.
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9
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Zhang Y, Liang X, Luo S, Chen Y, Li Y, Ma C, Li N, Gao N. Visualizing the nucleoplasmic maturation of human pre-60S ribosomal particles. Cell Res 2023; 33:867-878. [PMID: 37491604 PMCID: PMC10624882 DOI: 10.1038/s41422-023-00853-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/07/2023] [Indexed: 07/27/2023] Open
Abstract
Eukaryotic ribosome assembly is a highly orchestrated process that involves over two hundred protein factors. After early assembly events on nascent rRNA in the nucleolus, pre-60S particles undergo continuous maturation steps in the nucleoplasm, and prepare for nuclear export. Here, we report eleven cryo-EM structures of the nuclear pre-60S particles isolated from human cells through epitope-tagged GNL2, at resolutions of 2.8-4.3 Å. These high-resolution snapshots provide fine details for several major structural remodeling events at a virtual temporal resolution. Two new human nuclear factors, L10K and C11orf98, were also identified. Comparative structural analyses reveal that many assembly factors act as successive place holders to control the timing of factor association/dissociation events. They display multi-phasic binding properties for different domains and generate complex binding inter-dependencies as a means to guide the rRNA maturation process towards its mature conformation. Overall, our data reveal that nuclear assembly of human pre-60S particles is generally hierarchical with short branch pathways, and a few factors display specific roles as rRNA chaperones by confining rRNA helices locally to facilitate their folding, such as the C-terminal domain of SDAD1.
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Affiliation(s)
- Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Xiaomeng Liang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Sha Luo
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Yan Chen
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Yu Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Chengying Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
- Changping Laboratory, Beijing, China.
- National Biomedical Imaging Center, Peking University, Beijing, China.
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10
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Bohnsack KE, Yi S, Venus S, Jankowsky E, Bohnsack MT. Cellular functions of eukaryotic RNA helicases and their links to human diseases. Nat Rev Mol Cell Biol 2023; 24:749-769. [PMID: 37474727 DOI: 10.1038/s41580-023-00628-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/22/2023]
Abstract
RNA helicases are highly conserved proteins that use nucleoside triphosphates to bind or remodel RNA, RNA-protein complexes or both. RNA helicases are classified into the DEAD-box, DEAH/RHA, Ski2-like, Upf1-like and RIG-I families, and are the largest class of enzymes active in eukaryotic RNA metabolism - virtually all aspects of gene expression and its regulation involve RNA helicases. Mutation and dysregulation of these enzymes have been linked to a multitude of diseases, including cancer and neurological disorders. In this Review, we discuss the regulation and functional mechanisms of RNA helicases and their roles in eukaryotic RNA metabolism, including in transcription regulation, pre-mRNA splicing, ribosome assembly, translation and RNA decay. We highlight intriguing models that link helicase structure, mechanisms of function (such as local strand unwinding, translocation, winching, RNA clamping and displacing RNA-binding proteins) and biological roles, including emerging connections between RNA helicases and cellular condensates formed through liquid-liquid phase separation. We also discuss associations of RNA helicases with human diseases and recent efforts towards the design of small-molecule inhibitors of these pivotal regulators of eukaryotic gene expression.
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Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
| | - Soon Yi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Moderna, Cambridge, MA, USA.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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11
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Sheu-Gruttadauria J, Yan X, Stuurman N, Floor SN, Vale RD. Nucleolar dynamics are determined by the ordered assembly of the ribosome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559432. [PMID: 37808656 PMCID: PMC10557630 DOI: 10.1101/2023.09.26.559432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Ribosome biogenesis is coordinated within the nucleolus, a biomolecular condensate that exhibits dynamic material properties that are thought to be important for nucleolar function. However, the relationship between ribosome assembly and nucleolar dynamics is not clear. Here, we screened 364 genes involved in ribosome biogenesis and RNA metabolism for their impact on dynamics of the nucleolus, as measured by automated, high-throughput fluorescence recovery after photobleaching (FRAP) of the nucleolar scaffold protein NPM1. This screen revealed that gene knockdowns that caused accumulation of early rRNA intermediates were associated with nucleolar rigidification, while accumulation of late intermediates led to increased fluidity. These shifts in dynamics were accompanied by distinct changes in nucleolar morphology. We also found that genes involved in mRNA processing impact nucleolar dynamics, revealing connections between ribosome biogenesis and other RNA processing pathways. Together, this work defines mechanistic ties between ribosome assembly and the biophysical features of the nucleolus, while establishing a toolbox for understanding how molecular dynamics impact function across other biomolecular condensates.
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Affiliation(s)
- Jessica Sheu-Gruttadauria
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
| | - Xiaowei Yan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Present address: Department of Dermatology, Stanford, CA, USA
| | - Nico Stuurman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Present address: Altos Labs, Redwood City, CA, USA
| | - Stephen N. Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Ronald D. Vale
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
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12
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Sheng K, Li N, Rabuck-Gibbons JN, Dong X, Lyumkis D, Williamson JR. Assembly landscape for the bacterial large ribosomal subunit. Nat Commun 2023; 14:5220. [PMID: 37633970 PMCID: PMC10460392 DOI: 10.1038/s41467-023-40859-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 08/14/2023] [Indexed: 08/28/2023] Open
Abstract
Assembly of ribosomes in bacteria is highly efficient, taking ~2-3 min, but this makes the abundance of assembly intermediates very low, which is a challenge for mechanistic understanding. Genetic perturbations of the assembly process create bottlenecks where intermediates accumulate, facilitating structural characterization. We use cryo-electron microscopy, with iterative subclassification to identify intermediates in the assembly of the 50S ribosomal subunit from E. coli. The analysis of the ensemble of intermediates that spans the entire biogenesis pathway for the 50 S subunit was facilitated by a dimensionality reduction and cluster picking approach using PCA-UMAP-HDBSCAN. The identity of the cooperative folding units in the RNA with associated proteins is revealed, and the hierarchy of these units reveals a complete assembly map for all RNA and protein components. The assembly generally proceeds co-transcriptionally, with some flexibility in the landscape to ensure efficiency for this central cellular process under a variety of growth conditions.
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Affiliation(s)
- Kai Sheng
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Ning Li
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jessica N Rabuck-Gibbons
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Xiyu Dong
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Dmitry Lyumkis
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Graduate School of Biological Sciences, Section of Molecular Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - James R Williamson
- Department of Integrative Structural and Computational Biology, Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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13
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Castillo Duque de Estrada NM, Thoms M, Flemming D, Hammaren HM, Buschauer R, Ameismeier M, Baßler J, Beck M, Beckmann R, Hurt E. Structure of nascent 5S RNPs at the crossroad between ribosome assembly and MDM2-p53 pathways. Nat Struct Mol Biol 2023; 30:1119-1131. [PMID: 37291423 PMCID: PMC10442235 DOI: 10.1038/s41594-023-01006-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 03/26/2023] [Indexed: 06/10/2023]
Abstract
The 5S ribonucleoprotein (RNP) is assembled from its three components (5S rRNA, Rpl5/uL18 and Rpl11/uL5) before being incorporated into the pre-60S subunit. However, when ribosome synthesis is disturbed, a free 5S RNP can enter the MDM2-p53 pathway to regulate cell cycle and apoptotic signaling. Here we reconstitute and determine the cryo-electron microscopy structure of the conserved hexameric 5S RNP with fungal or human factors. This reveals how the nascent 5S rRNA associates with the initial nuclear import complex Syo1-uL18-uL5 and, upon further recruitment of the nucleolar factors Rpf2 and Rrs1, develops into the 5S RNP precursor that can assemble into the pre-ribosome. In addition, we elucidate the structure of another 5S RNP intermediate, carrying the human ubiquitin ligase Mdm2, which unravels how this enzyme can be sequestered from its target substrate p53. Our data provide molecular insight into how the 5S RNP can mediate between ribosome biogenesis and cell proliferation.
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Affiliation(s)
| | - Matthias Thoms
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Henrik M Hammaren
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Robert Buschauer
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Jochen Baßler
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Martin Beck
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Roland Beckmann
- Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.
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14
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Vanden Broeck A, Klinge S. Principles of human pre-60 S biogenesis. Science 2023; 381:eadh3892. [PMID: 37410842 DOI: 10.1126/science.adh3892] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/20/2023] [Indexed: 07/08/2023]
Abstract
During the early stages of human large ribosomal subunit (60S) biogenesis, an ensemble of assembly factors establishes and fine-tunes the essential RNA functional centers of pre-60S particles by an unknown mechanism. Here, we report a series of cryo-electron microscopy structures of human nucleolar and nuclear pre-60S assembly intermediates at resolutions of 2.5 to 3.2 angstroms. These structures show how protein interaction hubs tether assembly factor complexes to nucleolar particles and how guanosine triphosphatases and adenosine triphosphatase couple irreversible nucleotide hydrolysis steps to the installation of functional centers. Nuclear stages highlight how a conserved RNA-processing complex, the rixosome, couples large-scale RNA conformational changes with pre-ribosomal RNA processing by the RNA degradation machinery. Our ensemble of human pre-60S particles provides a rich foundation with which to elucidate the molecular principles of ribosome formation.
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Affiliation(s)
- Arnaud Vanden Broeck
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Sebastian Klinge
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY 10065, USA
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15
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Lau B, Huang Z, Kellner N, Niu S, Berninghausen O, Beckmann R, Hurt E, Cheng J. Mechanism of 5S RNP recruitment and helicase-surveilled rRNA maturation during pre-60S biogenesis. EMBO Rep 2023; 24:e56910. [PMID: 37129998 PMCID: PMC10328080 DOI: 10.15252/embr.202356910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023] Open
Abstract
Ribosome biogenesis proceeds along a multifaceted pathway from the nucleolus to the cytoplasm that is extensively coupled to several quality control mechanisms. However, the mode by which 5S ribosomal RNA is incorporated into the developing pre-60S ribosome, which in humans links ribosome biogenesis to cell proliferation by surveillance by factors such as p53-MDM2, is poorly understood. Here, we report nine nucleolar pre-60S cryo-EM structures from Chaetomium thermophilum, one of which clarifies the mechanism of 5S RNP incorporation into the early pre-60S. Successive assembly states then represent how helicases Dbp10 and Spb4, and the Pumilio domain factor Puf6 act in series to surveil the gradual folding of the nearby 25S rRNA domain IV. Finally, the methyltransferase Spb1 methylates a universally conserved guanine nucleotide in the A-loop of the peptidyl transferase center, thereby licensing further maturation. Our findings provide insight into the hierarchical action of helicases in safeguarding rRNA tertiary structure folding and coupling to surveillance mechanisms that culminate in local RNA modification.
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Affiliation(s)
- Benjamin Lau
- Heidelberg University Biochemistry Center (BZH)HeidelbergGermany
| | - Zixuan Huang
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co‐laboratory of Medical Epigenetics and MetabolismFudan UniversityShanghaiChina
| | - Nikola Kellner
- Heidelberg University Biochemistry Center (BZH)HeidelbergGermany
| | | | | | - Roland Beckmann
- Gene CenterLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH)HeidelbergGermany
| | - Jingdong Cheng
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co‐laboratory of Medical Epigenetics and MetabolismFudan UniversityShanghaiChina
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16
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Seidel M, Romanov N, Obarska-Kosinska A, Becker A, Trevisan Doimo de Azevedo N, Provaznik J, Nagaraja SR, Landry JJM, Benes V, Beck M. Co-translational binding of importins to nascent proteins. Nat Commun 2023; 14:3418. [PMID: 37296145 PMCID: PMC10256725 DOI: 10.1038/s41467-023-39150-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Various cellular quality control mechanisms support proteostasis. While, ribosome-associated chaperones prevent the misfolding of nascent chains during translation, importins were shown to prevent the aggregation of specific cargoes in a post-translational mechanism prior the import into the nucleoplasm. Here, we hypothesize that importins may already bind ribosome-associated cargo in a co-translational manner. We systematically measure the nascent chain association of all importins in Saccharomyces cerevisiae by selective ribosome profiling. We identify a subset of importins that bind to a wide range of nascent, often uncharacterized cargoes. This includes ribosomal proteins, chromatin remodelers and RNA binding proteins that are aggregation prone in the cytosol. We show that importins act consecutively with other ribosome-associated chaperones. Thus, the nuclear import system is directly intertwined with nascent chain folding and chaperoning.
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Affiliation(s)
- Maximilian Seidel
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
- Faculty of Bioscience, Heidelberg University, Heidelberg, Germany
| | - Natalie Romanov
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | | | - Anja Becker
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | | | - Jan Provaznik
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Sankarshana R Nagaraja
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Jonathan J M Landry
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Vladimir Benes
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Martin Beck
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany.
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt, Germany.
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17
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Sanghai ZA, Piwowarczyk R, Broeck AV, Klinge S. A co-transcriptional ribosome assembly checkpoint controls nascent large ribosomal subunit maturation. Nat Struct Mol Biol 2023; 30:594-599. [PMID: 37037974 DOI: 10.1038/s41594-023-00947-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/24/2023] [Indexed: 04/12/2023]
Abstract
During transcription of eukaryotic ribosomal DNA in the nucleolus, assembly checkpoints exist that guarantee the formation of stable precursors of small and large ribosomal subunits. While the formation of an early large subunit assembly checkpoint precedes the separation of small and large subunit maturation, its mechanism of action and function remain unknown. Here, we report the cryo-electron microscopy structure of the yeast co-transcriptional large ribosomal subunit assembly intermediate that serves as a checkpoint. The structure provides the mechanistic basis for how quality-control pathways are established through co-transcriptional ribosome assembly factors, that structurally interrogate, remodel and, together with ribosomal proteins, cooperatively stabilize correctly folded pre-ribosomal RNA. Our findings thus provide a molecular explanation for quality control during eukaryotic ribosome assembly in the nucleolus.
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Affiliation(s)
- Zahra A Sanghai
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York, USA
| | - Rafal Piwowarczyk
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York, USA
| | - Arnaud Vanden Broeck
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York, USA
| | - Sebastian Klinge
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York, USA.
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18
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Broeck AV, Klinge S. Principles of human pre-60 S biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532478. [PMID: 36993238 PMCID: PMC10054963 DOI: 10.1101/2023.03.14.532478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
During early stages of human large ribosomal subunit (60 S ) biogenesis, an ensemble of assembly factors establishes and fine-tunes the essential RNA functional centers of pre-60 S particles by an unknown mechanism. Here, we report a series of cryo-electron microscopy structures of human nucleolar and nuclear pre-60 S assembly intermediates at resolutions of 2.5-3.2 Ã…. These structures show how protein interaction hubs tether assembly factor complexes to nucleolar particles and how GTPases and ATPases couple irreversible nucleotide hydrolysis steps to the installation of functional centers. Nuclear stages highlight how a conserved RNA processing complex, the rixosome, couples large-scale RNA conformational changes to pre-rRNA processing by the RNA degradation machinery. Our ensemble of human pre-60 S particles provides a rich foundation to elucidate the molecular principles of ribosome formation. One-Sentence Summary High-resolution cryo-EM structures of human pre-60S particles reveal new principles of eukaryotic ribosome assembly.
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19
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Sekulski K, Cruz VE, Weirich CS, Erzberger JP. rRNA methylation by Spb1 regulates the GTPase activity of Nog2 during 60S ribosomal subunit assembly. Nat Commun 2023; 14:1207. [PMID: 36864048 PMCID: PMC9981671 DOI: 10.1038/s41467-023-36867-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 02/17/2023] [Indexed: 03/04/2023] Open
Abstract
Biogenesis of the large ribosomal (60S) subunit involves the assembly of three rRNAs and 46 proteins, a process requiring approximately 70 ribosome biogenesis factors (RBFs) that bind and release the pre-60S at specific steps along the assembly pathway. The methyltransferase Spb1 and the K-loop GTPase Nog2 are essential RBFs that engage the rRNA A-loop during sequential steps in 60S maturation. Spb1 methylates the A-loop nucleotide G2922 and a catalytically deficient mutant strain (spb1D52A) has a severe 60S biogenesis defect. However, the assembly function of this modification is currently unknown. Here, we present cryo-EM reconstructions that reveal that unmethylated G2922 leads to the premature activation of Nog2 GTPase activity and capture a Nog2-GDP-AlF4- transition state structure that implicates the direct involvement of unmodified G2922 in Nog2 GTPase activation. Genetic suppressors and in vivo imaging indicate that premature GTP hydrolysis prevents the efficient binding of Nog2 to early nucleoplasmic 60S intermediates. We propose that G2922 methylation levels regulate Nog2 recruitment to the pre-60S near the nucleolar/nucleoplasmic phase boundary, forming a kinetic checkpoint to regulate 60S production. Our approach and findings provide a template to study the GTPase cycles and regulatory factor interactions of the other K-loop GTPases involved in ribosome assembly.
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Affiliation(s)
- Kamil Sekulski
- Department of Biophysics, UT Southwestern Medical Center, 5323 Harry Hines Blvd., ND10.104B, Dallas, TX, 75390-8816, USA
| | - Victor Emmanuel Cruz
- Department of Biophysics, UT Southwestern Medical Center, 5323 Harry Hines Blvd., ND10.104B, Dallas, TX, 75390-8816, USA
| | - Christine S Weirich
- Department of Biophysics, UT Southwestern Medical Center, 5323 Harry Hines Blvd., ND10.104B, Dallas, TX, 75390-8816, USA
| | - Jan P Erzberger
- Department of Biophysics, UT Southwestern Medical Center, 5323 Harry Hines Blvd., ND10.104B, Dallas, TX, 75390-8816, USA.
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20
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Amin A, Wu R, Khan MA, Cheung MH, Liang Y, Liu C, Zhu G, Yu ZL, Liang C. An essential Noc3p dimerization cycle mediates ORC double-hexamer formation in replication licensing. Life Sci Alliance 2023; 6:e202201594. [PMID: 36599624 PMCID: PMC9813392 DOI: 10.26508/lsa.202201594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 01/05/2023] Open
Abstract
Replication licensing, a prerequisite of DNA replication, helps to ensure once-per-cell-cycle genome duplication. Some DNA replication-initiation proteins are sequentially loaded onto replication origins to form pre-replicative complexes (pre-RCs). ORC and Noc3p bind replication origins throughout the cell cycle, providing a platform for pre-RC assembly. We previously reported that cell cycle-dependent ORC dimerization is essential for the chromatin loading of the symmetric MCM double-hexamers. Here, we used Saccharomyces cerevisiae separation-of-function NOC3 mutants to confirm the separable roles of Noc3p in DNA replication and ribosome biogenesis. We also show that an essential and cell cycle-dependent Noc3p dimerization cycle regulates the ORC dimerization cycle. Noc3p dimerizes at the M-to-G1 transition and de-dimerizes in S-phase. The Noc3p dimerization cycle coupled with the ORC dimerization cycle enables replication licensing, protects nascent sister replication origins after replication initiation, and prevents re-replication. This study has revealed a new mechanism of replication licensing and elucidated the molecular mechanism of Noc3p as a mediator of ORC dimerization in pre-RC formation.
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Affiliation(s)
- Aftab Amin
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Rentian Wu
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Muhammad Ajmal Khan
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Man Hei Cheung
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Yanting Liang
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Changdong Liu
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Guang Zhu
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhi-Ling Yu
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Chun Liang
- Division of Life Science, Center for Cancer Research, and State Key Lab of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
- EnKang Pharmaceuticals (Guangzhou), Ltd., Guangzhou, China
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21
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Elliff J, Biswas A, Roshan P, Kuppa S, Patterson A, Mattice J, Chinnaraj M, Burd R, Walker SE, Pozzi N, Antony E, Bothner B, Origanti S. Dynamic states of eIF6 and SDS variants modulate interactions with uL14 of the 60S ribosomal subunit. Nucleic Acids Res 2023; 51:1803-1822. [PMID: 36651285 PMCID: PMC9976893 DOI: 10.1093/nar/gkac1266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 01/19/2023] Open
Abstract
Assembly of ribosomal subunits into active ribosomal complexes is integral to protein synthesis. Release of eIF6 from the 60S ribosomal subunit primes 60S to associate with the 40S subunit and engage in translation. The dynamics of eIF6 interaction with the uL14 (RPL23) interface of 60S and its perturbation by somatic mutations acquired in Shwachman-Diamond Syndrome (SDS) is yet to be clearly understood. Here, by using a modified strategy to obtain high yields of recombinant human eIF6 we have uncovered the critical interface entailing eight key residues in the C-tail of uL14 that is essential for physical interactions between 60S and eIF6. Disruption of the complementary binding interface by conformational changes in eIF6 disease variants provide a mechanism for weakened interactions of variants with the 60S. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) analyses uncovered dynamic configurational rearrangements in eIF6 induced by binding to uL14 and exposed an allosteric interface regulated by the C-tail of eIF6. Disrupting key residues in the eIF6-60S binding interface markedly limits proliferation of cancer cells, which highlights the significance of therapeutically targeting this interface. Establishing these key interfaces thus provide a therapeutic framework for targeting eIF6 in cancers and SDS.
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Affiliation(s)
- Jonah Elliff
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
- Department of Immunology, The University of Iowa, Iowa City, IA 52242, USA
| | - Aparna Biswas
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
| | - Poonam Roshan
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
| | - Sahiti Kuppa
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Angela Patterson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Jenna Mattice
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Mathivanan Chinnaraj
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Ryan Burd
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Sarah E Walker
- Department of Biological Sciences, State University of New York, Buffalo, NY 14260, USA
| | - Nicola Pozzi
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Sofia Origanti
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
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22
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Inhibition of Ribosome Assembly and Ribosome Translation Has Distinctly Different Effects on Abundance and Paralogue Composition of Ribosomal Protein mRNAs in Saccharomyces cerevisiae. mSystems 2023; 8:e0109822. [PMID: 36651729 PMCID: PMC9948716 DOI: 10.1128/msystems.01098-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Many mutations in genes for ribosomal proteins (r-proteins) and assembly factors cause cell stress and altered cell fate, resulting in congenital diseases collectively called ribosomopathies. Even though all such mutations depress the cell's protein synthesis capacity, they generate many different phenotypes, suggesting that the diseases are not due simply to insufficient protein synthesis capacity. To learn more, we investigated how the global transcriptome in Saccharomyces cerevisiae responds to reduced protein synthesis generated in two different ways: abolishing the assembly of new ribosomes and inhibiting ribosomal function. Our results showed that the mechanism by which protein synthesis is obstructed affects the ribosomal protein transcriptome differentially: ribosomal protein mRNA abundance increases during the abolition of ribosome formation but decreases during the inhibition of ribosome function. Interestingly, the ratio between mRNAs from some, but not all, pairs of paralogous ribosomal protein genes encoding slightly different versions of a given r-protein changed differently during the two types of stress, suggesting that expression of specific ribosomal protein paralogous mRNAs may contribute to the stress response. Unexpectedly, the abundance of transcripts for ribosome assembly factors and translation factors remained relatively unaffected by the stresses. On the other hand, the state of the translation apparatus did affect cell physiology: mRNA levels for some other proteins not directly related to the translation apparatus also changed differentially, though not coordinately with the r-protein genes, in response to the stresses. IMPORTANCE Mutations in genes for ribosomal proteins or assembly factors cause a variety of diseases called ribosomopathies. These diseases are typically ascribed to a reduction in the cell's capacity for protein synthesis. Paradoxically, ribosomal mutations result in a wide variety of disease phenotypes, even though they all reduce protein synthesis. Here, we show that the transcriptome changes differently depending on how the protein synthesis capacity is reduced. Most strikingly, inhibiting ribosome formation and ribosome function had opposite effects on the abundance of mRNA for ribosomal proteins, while genes for ribosome translation and assembly factors showed no systematic responses. Thus, the process by which the protein synthesis capacity is reduced contributes decisively to global mRNA composition. This emphasis on process is a new concept in understanding ribosomopathies and other stress responses.
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23
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Cryo-EM captures early ribosome assembly in action. Nat Commun 2023; 14:898. [PMID: 36797249 PMCID: PMC9935924 DOI: 10.1038/s41467-023-36607-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/08/2023] [Indexed: 02/18/2023] Open
Abstract
Ribosome biogenesis is a fundamental multi-step cellular process in all domains of life that involves the production, processing, folding, and modification of ribosomal RNAs (rRNAs) and ribosomal proteins. To obtain insights into the still unexplored early assembly phase of the bacterial 50S subunit, we exploited a minimal in vitro reconstitution system using purified ribosomal components and scalable reaction conditions. Time-limited assembly assays combined with cryo-EM analysis visualizes the structurally complex assembly pathway starting with a particle consisting of ordered density for only ~500 nucleotides of 23S rRNA domain I and three ribosomal proteins. In addition, our structural analysis reveals that early 50S assembly occurs in a domain-wise fashion, while late 50S assembly proceeds incrementally. Furthermore, we find that both ribosomal proteins and folded rRNA helices, occupying surface exposed regions on pre-50S particles, induce, or stabilize rRNA folds within adjacent regions, thereby creating cooperativity.
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24
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Parker MD, Karbstein K. Quality control ensures fidelity in ribosome assembly and cellular health. J Cell Biol 2023; 222:213871. [PMID: 36790396 PMCID: PMC9960125 DOI: 10.1083/jcb.202209115] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/09/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023] Open
Abstract
The coordinated integration of ribosomal RNA and protein into two functional ribosomal subunits is safeguarded by quality control checkpoints that ensure ribosomes are correctly assembled and functional before they engage in translation. Quality control is critical in maintaining the integrity of ribosomes and necessary to support healthy cell growth and prevent diseases associated with mistakes in ribosome assembly. Its importance is demonstrated by the finding that bypassing quality control leads to misassembled, malfunctioning ribosomes with altered translation fidelity, which change gene expression and disrupt protein homeostasis. In this review, we outline our understanding of quality control within ribosome synthesis and how failure to enforce quality control contributes to human disease. We first provide a definition of quality control to guide our investigation, briefly present the main assembly steps, and then examine stages of assembly that test ribosome function, establish a pass-fail system to evaluate these functions, and contribute to altered ribosome performance when bypassed, and are thus considered "quality control."
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Affiliation(s)
- Melissa D. Parker
- The Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, La Jolla, CA, USA,University of Florida—Scripps Biomedical Research, Jupiter, FL, USA
| | - Katrin Karbstein
- The Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, La Jolla, CA, USA,University of Florida—Scripps Biomedical Research, Jupiter, FL, USA,Howard Hughes Medical Institute Faculty Scholar, Howard Hughes Medical Institute, Chevy Chase, MD, USA,Correspondence to Katrin Karbstein:
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25
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Dörner K, Ruggeri C, Zemp I, Kutay U. Ribosome biogenesis factors-from names to functions. EMBO J 2023; 42:e112699. [PMID: 36762427 PMCID: PMC10068337 DOI: 10.15252/embj.2022112699] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/13/2022] [Accepted: 01/19/2023] [Indexed: 02/11/2023] Open
Abstract
The assembly of ribosomal subunits is a highly orchestrated process that involves a huge cohort of accessory factors. Most eukaryotic ribosome biogenesis factors were first identified by genetic screens and proteomic approaches of pre-ribosomal particles in Saccharomyces cerevisiae. Later, research on human ribosome synthesis not only demonstrated that the requirement for many of these factors is conserved in evolution, but also revealed the involvement of additional players, reflecting a more complex assembly pathway in mammalian cells. Yet, it remained a challenge for the field to assign a function to many of the identified factors and to reveal their molecular mode of action. Over the past decade, structural, biochemical, and cellular studies have largely filled this gap in knowledge and led to a detailed understanding of the molecular role that many of the players have during the stepwise process of ribosome maturation. Such detailed knowledge of the function of ribosome biogenesis factors will be key to further understand and better treat diseases linked to disturbed ribosome assembly, including ribosomopathies, as well as different types of cancer.
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Affiliation(s)
- Kerstin Dörner
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Chiara Ruggeri
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.,RNA Biology Ph.D. Program, Zurich, Switzerland
| | - Ivo Zemp
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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26
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Archaea/eukaryote-specific ribosomal proteins - guardians of a complex structure. Comput Struct Biotechnol J 2023; 21:1249-1261. [PMID: 36817958 PMCID: PMC9932298 DOI: 10.1016/j.csbj.2023.01.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/09/2023] [Accepted: 01/26/2023] [Indexed: 01/29/2023] Open
Abstract
In three domains of life, proteins are synthesized by large ribonucleoprotein particles called ribosomes. All ribosomes are composed of ribosomal RNAs (rRNA) and numerous ribosomal proteins (r-protein). The three-dimensional shape of ribosomes is mainly defined by a tertiary structure of rRNAs. In addition, rRNAs have a major role in decoding the information carried by messenger RNAs and catalyzing the peptide bond formation. R-proteins are essential for shaping the network of interactions that contribute to a various aspects of the protein synthesis machinery, including assembly of ribosomes and interaction of ribosomal subunits. Structural studies have revealed that many key components of ribosomes are conserved in all life domains. Besides the core structure, ribosomes contain domain-specific structural features that include additional r-proteins and extensions of rRNA and r-proteins. This review focuses specifically on those r-proteins that are found only in archaeal and eukaryotic ribosomes. The role of these archaea/eukaryote specific r-proteins in stabilizing the ribosome structure is discussed. Several examples illustrate their functions in the formation of the internal network of ribosomal subunits and interactions between the ribosomal subunits. In addition, the significance of these r-proteins in ribosome biogenesis and protein synthesis is highlighted.
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27
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Durand S, Bruelle M, Bourdelais F, Bennychen B, Blin-Gonthier J, Isaac C, Huyghe A, Martel S, Seyve A, Vanbelle C, Adrait A, Couté Y, Meyronet D, Catez F, Diaz JJ, Lavial F, Ricci EP, Ducray F, Gabut M. RSL24D1 sustains steady-state ribosome biogenesis and pluripotency translational programs in embryonic stem cells. Nat Commun 2023; 14:356. [PMID: 36690642 PMCID: PMC9870888 DOI: 10.1038/s41467-023-36037-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/13/2023] [Indexed: 01/24/2023] Open
Abstract
Embryonic stem cell (ESC) fate decisions are regulated by a complex circuitry that coordinates gene expression at multiple levels from chromatin to mRNA processing. Recently, ribosome biogenesis and translation have emerged as key pathways that efficiently control stem cell homeostasis, yet the underlying molecular mechanisms remain largely unknown. Here, we identified RSL24D1 as highly expressed in both mouse and human pluripotent stem cells. RSL24D1 is associated with nuclear pre-ribosomes and is required for the biogenesis of 60S subunits in mouse ESCs. Interestingly, RSL24D1 depletion significantly impairs global translation, particularly of key pluripotency factors and of components from the Polycomb Repressive Complex 2 (PRC2). While having a moderate impact on differentiation, RSL24D1 depletion significantly alters ESC self-renewal and lineage commitment choices. Altogether, these results demonstrate that RSL24D1-dependant ribosome biogenesis is both required to sustain the expression of pluripotent transcriptional programs and to silence PRC2-regulated developmental programs, which concertedly dictate ESC homeostasis.
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Affiliation(s)
- Sébastien Durand
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
| | - Marion Bruelle
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
| | - Fleur Bourdelais
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
- Inovarion, 75005, Paris, France
| | - Bigitha Bennychen
- Dept. of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, K1A 0R6, Canada
| | - Juliana Blin-Gonthier
- Laboratoire de Biologie et de Modélisation de la Cellule, ENS de Lyon, CNRS UMR 5239, Inserm U1293, Lyon, France
| | - Caroline Isaac
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
| | - Aurélia Huyghe
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
- Equipe labellisée la Ligue contre le cancer, Lyon, France
| | - Sylvie Martel
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
| | - Antoine Seyve
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Neuro-oncology department, Hospices Civils de Lyon, Lyon, France
| | - Christophe Vanbelle
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
| | - Annie Adrait
- University Grenoble Alpes, INSERM, CEA, UA13 BGE, CNRS, CEA, FR2048, 38000, Grenoble, France
| | - Yohann Couté
- University Grenoble Alpes, INSERM, CEA, UA13 BGE, CNRS, CEA, FR2048, 38000, Grenoble, France
| | - David Meyronet
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Institut de Pathologie Est, Hospices Civils de Lyon, Lyon, France
| | - Frédéric Catez
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
| | - Jean-Jacques Diaz
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
| | - Fabrice Lavial
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Labex Dev2Can, Lyon, France
- Equipe labellisée la Ligue contre le cancer, Lyon, France
| | - Emiliano P Ricci
- Laboratoire de Biologie et de Modélisation de la Cellule, ENS de Lyon, CNRS UMR 5239, Inserm U1293, Lyon, France
| | - François Ducray
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France
- Institut Convergence Plascan, Lyon, France
- Neuro-oncology department, Hospices Civils de Lyon, Lyon, France
| | - Mathieu Gabut
- Cancer Initiation and Tumoral Cell Identity (CITI) Department. Cancer Research Centre of Lyon (CRCL) INSERM 1052, CNRS 5286, Université Claude Bernard Lyon I, Centre Léon Bérard, Lyon, France.
- Institut Convergence Plascan, Lyon, France.
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28
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Guerra-Slompo E, Cesaro G, Guimarães B, Zanchin N. Dissecting Trypanosoma brucei RRP44 function in the maturation of segmented ribosomal RNA using a regulated genetic complementation system. Nucleic Acids Res 2023; 51:396-419. [PMID: 36610751 PMCID: PMC9841430 DOI: 10.1093/nar/gkac1217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 11/29/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
Trypanosoma brucei belongs to a group of protozoans presenting fragmented large subunit rRNA. Its LSU rRNA equivalent to the 25S/28S rRNA of other eukaryotes is split into six fragments, requiring additional processing for removal of the extra spacer sequences. We have used a genetic complementation strategy to further investigate the T. brucei RRP44 nuclease in pre-rRNA maturation. TbRRP44 contains both a PIN and a RNB domain whose homologues are found in association with the exosome complex. We found that the exonucleolytic activity of the RNB domain as well as the physical presence of the PIN domain are essential for TbRRP44 function, while a catalytic site mutation in the PIN domain has no detectable effect on cell growth. A new endonucleolytic cleavage site in ITS1 was identified. In addition to the 5.8S rRNA 3'-end maturation, TbRRP44 is required for degradation of the excised 5'-ETS and for removal of part of ITS1 during maturation of the 18S rRNA 3'-end. TbRRP44 deficiency leads to accumulation of many LSU intermediate precursors, most of them not detected in control cells. TbRRP44 is also required for U3 snoRNA and spliced leader processing, indicating that TbRRP44 may have a wide role in RNA processing in T. brucei.
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Affiliation(s)
- Eloise Pavão Guerra-Slompo
- Carlos Chagas Institute, Oswaldo Cruz Foundation, FIOCRUZ, R. Prof. Algacyr Munhoz Mader 3775, 81350-010, Curitiba-PR, Brazil
| | - Giovanna Cesaro
- Carlos Chagas Institute, Oswaldo Cruz Foundation, FIOCRUZ, R. Prof. Algacyr Munhoz Mader 3775, 81350-010, Curitiba-PR, Brazil,Biochemistry Postgraduate Program, Federal University of Paraná, Curitiba-PR, Brazil
| | - Beatriz Gomes Guimarães
- Carlos Chagas Institute, Oswaldo Cruz Foundation, FIOCRUZ, R. Prof. Algacyr Munhoz Mader 3775, 81350-010, Curitiba-PR, Brazil,Biochemistry Postgraduate Program, Federal University of Paraná, Curitiba-PR, Brazil
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29
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Khreiss A, Capeyrou R, Lebaron S, Albert B, Bohnsack K, Bohnsack M, Henry Y, Henras A, Humbert O. The DEAD-box protein Dbp6 is an ATPase and RNA annealase interacting with the peptidyl transferase center (PTC) of the ribosome. Nucleic Acids Res 2023; 51:744-764. [PMID: 36610750 PMCID: PMC9881158 DOI: 10.1093/nar/gkac1196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/21/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
Ribosomes are ribozymes, hence correct folding of the rRNAs during ribosome biogenesis is crucial to ensure catalytic activity. RNA helicases, which can modulate RNA-RNA and RNA/protein interactions, are proposed to participate in rRNA tridimensional folding. Here, we analyze the biochemical properties of Dbp6, a DEAD-box RNA helicase required for the conversion of the initial 90S pre-ribosomal particle into the first pre-60S particle. We demonstrate that in vitro, Dbp6 shows ATPase as well as annealing and clamping activities negatively regulated by ATP. Mutations in Dbp6 core motifs involved in ATP binding and ATP hydrolysis are lethal and impair Dbp6 ATPase activity but increase its RNA binding and RNA annealing activities. These data suggest that correct regulation of these activities is important for Dbp6 function in vivo. Using in vivo cross-linking (CRAC) experiments, we show that Dbp6 interacts with 25S rRNA sequences located in the 5' domain I and in the peptidyl transferase center (PTC), and also crosslinks to snoRNAs hybridizing to the immature PTC. We propose that the ATPase and RNA clamping/annealing activities of Dbp6 modulate interactions of snoRNAs with the immature PTC and/or contribute directly to the folding of this region.
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Affiliation(s)
- Ali Khreiss
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Régine Capeyrou
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Benjamin Albert
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany,Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, 37077 Göttingen, Germany
| | - Yves Henry
- Correspondence may also be addressed to Yves Henry. Tel: +33 5 61 33 59 53; Fax: +33 5 61 33 58 86;
| | - Anthony K Henras
- Correspondence may also be addressed to Anthony Henras. Tel: +33 5 61 33 59 55; Fax: +33 5 61 33 58 86;
| | - Odile Humbert
- To whom correspondence should be addressed. Tel: +33 5 61 33 59 52; Fax: +33 5 61 33 58 86;
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30
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Hariharan N, Ghosh S, Palakodeti D. The story of rRNA expansion segments: Finding functionality amidst diversity. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1732. [PMID: 35429135 DOI: 10.1002/wrna.1732] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 02/24/2022] [Accepted: 03/19/2022] [Indexed: 01/31/2023]
Abstract
Expansion segments (ESs) are multinucleotide insertions present across phyla at specific conserved positions in eukaryotic rRNAs. ESs are generally absent in bacterial rRNAs with some exceptions, while the archaeal rRNAs have microexpansions at regions that coincide with those of eukaryotic ESs. Although there is an increasing prominence of ribosomes, especially the ribosomal proteins, in fine-tuning gene expression through translation regulation, the role of rRNA ESs is relatively underexplored. While rRNAs have been established as the major catalytic hub in ribosome function, the presence of ESs widens their scope as a species-specific regulatory hub of protein synthesis. In this comprehensive review, we have elaborately discussed the current understanding of the functional aspects of rRNA ESs of cytoplasmic eukaryotic ribosomes and discuss their past, present, and future. This article is categorized under: RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems Translation > Ribosome Structure/Function Translation > Regulation.
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Affiliation(s)
- Nivedita Hariharan
- Technologies for the Advancement of Science, Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India.,The University of Trans-disciplinary Health Sciences and Technology, Bangalore, India
| | - Sumana Ghosh
- Manipal Academy of Higher Education, Manipal, India
| | - Dasaradhi Palakodeti
- Technologies for the Advancement of Science, Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
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31
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A single 2'-O-methylation of ribosomal RNA gates assembly of a functional ribosome. Nat Struct Mol Biol 2023; 30:91-98. [PMID: 36536102 PMCID: PMC9851907 DOI: 10.1038/s41594-022-00891-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 11/04/2022] [Indexed: 12/24/2022]
Abstract
RNA modifications are widespread in biology and abundant in ribosomal RNA. However, the importance of these modifications is not well understood. We show that methylation of a single nucleotide, in the catalytic center of the large subunit, gates ribosome assembly. Massively parallel mutational scanning of the essential nuclear GTPase Nog2 identified important interactions with rRNA, particularly with the 2'-O-methylated A-site base Gm2922. We found that methylation of G2922 is needed for assembly and efficient nuclear export of the large subunit. Critically, we identified single amino acid changes in Nog2 that completely bypass dependence on G2922 methylation and used cryoelectron microscopy to directly visualize how methylation flips Gm2922 into the active site channel of Nog2. This work demonstrates that a single RNA modification is a critical checkpoint in ribosome biogenesis, suggesting that such modifications can play an important role in regulation and assembly of macromolecular machines.
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32
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Cruz VE, Sekulski K, Peddada N, Sailer C, Balasubramanian S, Weirich CS, Stengel F, Erzberger JP. Sequence-specific remodeling of a topologically complex RNP substrate by Spb4. Nat Struct Mol Biol 2022; 29:1228-1238. [PMID: 36482249 PMCID: PMC10680166 DOI: 10.1038/s41594-022-00874-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 10/14/2022] [Indexed: 12/13/2022]
Abstract
DEAD-box ATPases are ubiquitous enzymes essential in all aspects of RNA biology. However, the limited in vitro catalytic activities described for these enzymes are at odds with their complex cellular roles, most notably in driving large-scale RNA remodeling steps during the assembly of ribonucleoproteins (RNPs). We describe cryo-EM structures of 60S ribosomal biogenesis intermediates that reveal how context-specific RNA unwinding by the DEAD-box ATPase Spb4 results in extensive, sequence-specific remodeling of rRNA secondary structure. Multiple cis and trans interactions stabilize Spb4 in a post-catalytic, high-energy intermediate that drives the organization of the three-way junction at the base of rRNA domain IV. This mechanism explains how limited strand separation by DEAD-box ATPases is leveraged to provide non-equilibrium directionality and ensure efficient and accurate RNP assembly.
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Affiliation(s)
- Victor Emmanuel Cruz
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Kamil Sekulski
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Nagesh Peddada
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Carolin Sailer
- Department of Biology, University of Konstanz, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
- Department of Biomedical Sciences, University of Copenhagen, København, Denmark
| | - Sahana Balasubramanian
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
- Cell Biology & Molecular Physiology Department, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christine S Weirich
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA
| | - Florian Stengel
- Department of Biology, University of Konstanz, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
| | - Jan P Erzberger
- Department of Biophysics, UT Southwestern Medical Center - ND10.124B, Dallas, TX, USA.
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33
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Chromatin localization of nucleophosmin organizes ribosome biogenesis. Mol Cell 2022; 82:4443-4457.e9. [PMID: 36423630 PMCID: PMC9949351 DOI: 10.1016/j.molcel.2022.10.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 09/01/2022] [Accepted: 10/28/2022] [Indexed: 11/24/2022]
Abstract
Ribosome biogenesis takes place in the nucleolus, a nuclear membrane-less organelle. Although well studied, it remains unknown how nascent ribosomal subunits separate from the central chromatin compartment and move to the outer granular component, where maturation occurs. We find that the Schizosaccharomyces pombe nucleophosmin-like protein Fkbp39 localizes to rDNA sites encoding the 60S subunit rRNA, and this localization contributes to its specific association with nascent 60S subunits. Fkbp39 dissociates from chromatin to bind nascent 60S subunits, causing the latter to partition away from chromatin and from nascent 40S subunits through liquid-liquid phase separation. In vivo, Fkbp39 binding directs the translocation of nascent 60S subunits toward the nucleophosmin-rich granular component. This process increases the efficiency of 60S subunit assembly, facilitating the incorporation of 60S RNA domain III. Thus, chromatin localization determines the specificity of nucleophosmin in sorting nascent ribosomal subunits and coordinates their movement into specialized assembly compartments within the nucleolus.
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34
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Meier UT. The daunting task of modifying ribosomal RNA. RNA (NEW YORK, N.Y.) 2022; 28:1555-1557. [PMID: 36109161 PMCID: PMC9670813 DOI: 10.1261/rna.079391.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
One of the most basic tasks of every cell is the synthesis of ribosomes, yet the process is so complex that we are only beginning to comprehend it. In human cells, the final product contains four RNAs and 79 proteins forming a large ribonucleoprotein, the ribosome. About twice as many factors are involved in assembly of these protein synthesizing machines. Additionally, some 200 small nucleolar ribonucleoproteins (snoRNPs) function in the modification of pre-ribosomal RNA (pre-rRNA) at a similar number of ribonucleotides. Modification is essential for proper function and biogenesis of ribosomes (Decatur and Fournier 2002; Sloan et al. 2016). While abrogation of individual modifications has little to no measurable effects, removal of a combination of modifications or of all causes severe to lethal effects. Modifications mostly cluster around the functional centers of the ribosome and some modifications are important for ribosome assembly. The subject of this perspective is to raise awareness to how modification at so many sites can be achieved while the pre-rRNA is being processed, folded and re-folded, and assembled with ribosomal proteins to yield the pre-ribosomal subunits in the nucleolus (Baßler and Hurt 2019). This is not a comprehensive review but a simplification of complex issues providing access to the general reader.
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Affiliation(s)
- U Thomas Meier
- Albert Einstein College of Medicine, Bronx, New York 10461, USA
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35
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Mechanisms and players of mitoribosomal biogenesis revealed in trypanosomatids. Trends Parasitol 2022; 38:1053-1067. [PMID: 36075844 DOI: 10.1016/j.pt.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/29/2022] [Accepted: 08/16/2022] [Indexed: 01/13/2023]
Abstract
Translation in mitochondria is mediated by mitochondrial ribosomes, or mitoribosomes, complex ribonucleoprotein machines with dual genetic origin. Mitoribosomes in trypanosomatid parasites diverged markedly from their bacterial ancestors and other eukaryotic lineages in terms of protein composition, rRNA content, and overall architecture, yet their core functional elements remained conserved. Recent cryo-electron microscopy studies provided atomic models of trypanosomatid large and small mitoribosomal subunits and their precursors, making these parasites the organisms with the best-understood biogenesis of mitoribosomes. The structures revealed molecular mechanisms and players involved in the assembly of mitoribosomes not only in the parasites, but also in eukaryotes in general.
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36
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Cheng J, Lau B, Thoms M, Ameismeier M, Berninghausen O, Hurt E, Beckmann R. The nucleoplasmic phase of pre-40S formation prior to nuclear export. Nucleic Acids Res 2022; 50:11924-11937. [PMID: 36321656 PMCID: PMC9723619 DOI: 10.1093/nar/gkac961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/04/2022] [Accepted: 10/21/2022] [Indexed: 11/07/2022] Open
Abstract
Biogenesis of the small ribosomal subunit in eukaryotes starts in the nucleolus with the formation of a 90S precursor and ends in the cytoplasm. Here, we elucidate the enigmatic structural transitions of assembly intermediates from human and yeast cells during the nucleoplasmic maturation phase. After dissociation of all 90S factors, the 40S body adopts a close-to-mature conformation, whereas the 3' major domain, later forming the 40S head, remains entirely immature. A first coordination is facilitated by the assembly factors TSR1 and BUD23-TRMT112, followed by re-positioning of RRP12 that is already recruited early to the 90S for further head rearrangements. Eventually, the uS2 cluster, CK1 (Hrr25 in yeast) and the export factor SLX9 associate with the pre-40S to provide export competence. These exemplary findings reveal the evolutionary conserved mechanism of how yeast and humans assemble the 40S ribosomal subunit, but reveal also a few minor differences.
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Affiliation(s)
- Jingdong Cheng
- Gene Center and Department of Biochemistry, University of Munich LMU, Feodor-Lynen-Str. 25, 81377 Munich, Germany,Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Dong’an Road 131, 200032 Shanghai, China
| | - Benjamin Lau
- BZH, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Matthias Thoms
- Gene Center and Department of Biochemistry, University of Munich LMU, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Michael Ameismeier
- Gene Center and Department of Biochemistry, University of Munich LMU, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Otto Berninghausen
- Gene Center and Department of Biochemistry, University of Munich LMU, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Ed Hurt
- Correspondence may also be addressed to Ed Hurt.
| | - Roland Beckmann
- To whom correspondence should be addressed. Tel: +49 89 218076900; Fax: +49 89 218076945;
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37
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McCool MA, Buhagiar AF, Bryant CJ, Ogawa LM, Abriola L, Surovtseva YV, Baserga SJ. Human pre-60S assembly factors link rRNA transcription to pre-rRNA processing. RNA (NEW YORK, N.Y.) 2022; 29:rna.079149.122. [PMID: 36323459 PMCID: PMC9808572 DOI: 10.1261/rna.079149.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
In eukaryotes, the nucleolus is the site of ribosome biosynthesis, an essential process in all cells. While human ribosome assembly is largely evolutionarily conserved, many of the regulatory details underlying its control and function have not yet been well-defined. The nucleolar protein RSL24D1 was originally identified as a factor important for 60S ribosomal subunit biogenesis. In addition, the PeBoW (BOP1-PES1-WDR12) complex has been well-defined as required for pre-28S rRNA processing and cell proliferation. In this study, we show that RSL24D1 depletion impairs both pre-ribosomal RNA (pre-rRNA) transcription and mature 28S rRNA production, leading to decreased protein synthesis and p53 stabilization in human cells. Surprisingly, each of the PeBoW complex members is also required for pre-rRNA transcription. We demonstrate that RSL24D1 and WDR12 co-immunoprecipitate with the RNA polymerase I subunit, RPA194, and regulate its steady state levels. These results uncover the dual role of RSL24D1 and the PeBoW complex in multiple steps of ribosome biogenesis, and provide evidence implicating large ribosomal subunit biogenesis factors in pre-rRNA transcription control.
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38
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Biesiada M, Hu MY, Williams LD, Purzycka KJ, Petrov AS. rRNA expansion segment 7 in eukaryotes: from Signature Fold to tentacles. Nucleic Acids Res 2022; 50:10717-10732. [PMID: 36200812 PMCID: PMC9561286 DOI: 10.1093/nar/gkac844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 09/13/2022] [Accepted: 09/22/2022] [Indexed: 11/14/2022] Open
Abstract
The ribosomal core is universally conserved across the tree of life. However, eukaryotic ribosomes contain diverse rRNA expansion segments (ESs) on their surfaces. Sites of ES insertions are predicted from sites of insertion of micro-ESs in archaea. Expansion segment 7 (ES7) is one of the most diverse regions of the ribosome, emanating from a short stem loop and ranging to over 750 nucleotides in mammals. We present secondary and full-atom 3D structures of ES7 from species spanning eukaryotic diversity. Our results are based on experimental 3D structures, the accretion model of ribosomal evolution, phylogenetic relationships, multiple sequence alignments, RNA folding algorithms and 3D modeling by RNAComposer. ES7 contains a distinct motif, the 'ES7 Signature Fold', which is generally invariant in 2D topology and 3D structure in all eukaryotic ribosomes. We establish a model in which ES7 developed over evolution through a series of elementary and recursive growth events. The data are sufficient to support an atomic-level accretion path for rRNA growth. The non-monophyletic distribution of some ES7 features across the phylogeny suggests acquisition via convergent processes. And finally, illustrating the power of our approach, we constructed the 2D and 3D structure of the entire LSU rRNA of Mus musculus.
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Affiliation(s)
- Marcin Biesiada
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland
| | - Michael Y Hu
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Loren Dean Williams
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Katarzyna J Purzycka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland
| | - Anton S Petrov
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
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39
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Prattes M, Grishkovskaya I, Hodirnau VV, Hetzmannseder C, Zisser G, Sailer C, Kargas V, Loibl M, Gerhalter M, Kofler L, Warren AJ, Stengel F, Haselbach D, Bergler H. Visualizing maturation factor extraction from the nascent ribosome by the AAA-ATPase Drg1. Nat Struct Mol Biol 2022; 29:942-953. [PMID: 36097293 PMCID: PMC9507969 DOI: 10.1038/s41594-022-00832-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 08/03/2022] [Indexed: 11/23/2022]
Abstract
The AAA-ATPase Drg1 is a key factor in eukaryotic ribosome biogenesis that initiates cytoplasmic maturation of the large ribosomal subunit. Drg1 releases the shuttling maturation factor Rlp24 from pre-60S particles shortly after nuclear export, a strict requirement for downstream maturation. The molecular mechanism of release remained elusive. Here, we report a series of cryo-EM structures that captured the extraction of Rlp24 from pre-60S particles by Saccharomyces cerevisiae Drg1. These structures reveal that Arx1 and the eukaryote-specific rRNA expansion segment ES27 form a joint docking platform that positions Drg1 for efficient extraction of Rlp24 from the pre-ribosome. The tips of the Drg1 N domains thereby guide the Rlp24 C terminus into the central pore of the Drg1 hexamer, enabling extraction by a hand-over-hand translocation mechanism. Our results uncover substrate recognition and processing by Drg1 step by step and provide a comprehensive mechanistic picture of the conserved modus operandi of AAA-ATPases.
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Affiliation(s)
- Michael Prattes
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Irina Grishkovskaya
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, Austria
| | | | | | - Gertrude Zisser
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Carolin Sailer
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Vasileios Kargas
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Cambridge, UK
- Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, UK
- Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Mathias Loibl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | | | - Lisa Kofler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Alan J Warren
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Cambridge, UK
- Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, UK
- Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, UK
| | - Florian Stengel
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David Haselbach
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, Austria.
| | - Helmut Bergler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
- Field of Excellence BioHealth - University of Graz, Graz, Austria.
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40
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Bhutada P, Favre S, Jaafar M, Hafner J, Liesinger L, Unterweger S, Bischof K, Darnhofer B, Siva Sankar D, Rechberger G, Abou Merhi R, Lebaron S, Birner-Gruenberger R, Kressler D, Henras AK, Pertschy B. Rbp95 binds to 25S rRNA helix H95 and cooperates with the Npa1 complex during early pre-60S particle maturation. Nucleic Acids Res 2022; 50:10053-10077. [PMID: 36018804 PMCID: PMC9508819 DOI: 10.1093/nar/gkac724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/21/2022] Open
Abstract
Eukaryotic ribosome synthesis involves more than 200 assembly factors, which promote ribosomal RNA (rRNA) processing, modification and folding, and assembly of ribosomal proteins. The formation and maturation of the earliest pre-60S particles requires structural remodeling by the Npa1 complex, but is otherwise still poorly understood. Here, we introduce Rbp95 (Ycr016w), a constituent of early pre-60S particles, as a novel ribosome assembly factor. We show that Rbp95 is both genetically and physically linked to most Npa1 complex members and to ribosomal protein Rpl3. We demonstrate that Rbp95 is an RNA-binding protein containing two independent RNA-interacting domains. In vivo, Rbp95 associates with helix H95 in the 3′ region of the 25S rRNA, in close proximity to the binding sites of Npa1 and Rpl3. Additionally, Rbp95 interacts with several snoRNAs. The absence of Rbp95 results in alterations in the protein composition of early pre-60S particles. Moreover, combined mutation of Rbp95 and Npa1 complex members leads to a delay in the maturation of early pre-60S particles. We propose that Rbp95 acts together with the Npa1 complex during early pre-60S maturation, potentially by promoting pre-rRNA folding events within pre-60S particles.
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Affiliation(s)
- Priya Bhutada
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Sébastien Favre
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.,Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Jutta Hafner
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Laura Liesinger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Stefan Unterweger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Karin Bischof
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Barbara Darnhofer
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - Devanarayanan Siva Sankar
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Gerald Rechberger
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Raghida Abou Merhi
- Genomic Stability and Biotherapy (GSBT) Laboratory, Faculty of Sciences, Rafik Hariri Campus, Lebanese University, Beirut, Lebanon
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Ruth Birner-Gruenberger
- BioTechMed-Graz, Graz, Austria.,Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria.,Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/E164, 1060 Vienna, Austria
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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41
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Moraleva AA, Deryabin AS, Rubtsov YP, Rubtsova MP, Dontsova OA. Eukaryotic Ribosome Biogenesis: The 60S Subunit. Acta Naturae 2022; 14:39-49. [PMID: 35925480 PMCID: PMC9307984 DOI: 10.32607/actanaturae.11541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 02/11/2022] [Indexed: 11/20/2022] Open
Abstract
Ribosome biogenesis is consecutive coordinated maturation of ribosomal precursors in the nucleolus, nucleoplasm, and cytoplasm. The formation of mature ribosomal subunits involves hundreds of ribosomal biogenesis factors that ensure ribosomal RNA processing, tertiary structure, and interaction with ribosomal proteins. Although the main features and stages of ribosome biogenesis are conservative among different groups of eukaryotes, this process in human cells has become more complicated due to the larger size of the ribosomes and pre-ribosomes and intricate regulatory pathways affecting their assembly and function. Many of the factors involved in the biogenesis of human ribosomes have been identified using genome-wide screening based on RNA interference. A previous part of this review summarized recent data on the processing of the primary rRNA transcript and compared the maturation of the small 40S subunit in yeast and human cells. This part of the review focuses on the biogenesis of the large 60S subunit of eukaryotic ribosomes.
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Affiliation(s)
- A. A. Moraleva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
| | - A. S. Deryabin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
| | - Yu. P. Rubtsov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
| | - M. P. Rubtsova
- Lomonosov Moscow State University, Faculty of Chemistry, Moscow, 119991 Russia
| | - O. A. Dontsova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
- Lomonosov Moscow State University, Faculty of Chemistry, Moscow, 119991 Russia
- Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
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42
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Lin S, Rajan S, Lemberg S, Altawil M, Anderson K, Bryant R, Cappeta S, Chin B, Hamdan I, Hamer A, Hyzny R, Karp A, Lee D, Lim A, Nayak M, Palaniappan V, Park S, Satishkumar S, Seth A, Sri Dasari U, Toppari E, Vyas A, Walker J, Weston E, Zafar A, Zielke C, Mahabeleshwar GH, Tartakoff AM. Production of nascent ribosome precursors within the nucleolar microenvironment of Saccharomyces cerevisiae. Genetics 2022; 221:iyac070. [PMID: 35657327 PMCID: PMC9252279 DOI: 10.1093/genetics/iyac070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
35S rRNA transcripts include a 5'-external transcribed spacer followed by rRNAs of the small and large ribosomal subunits. Their processing yields massive precursors that include dozens of assembly factor proteins. In Saccharomyces cerevisiae, nucleolar assembly factors form 2 coaxial layers/volumes around ribosomal DNA. Most of these factors are cyclically recruited from a latent state to an operative state, and are extensively conserved. The layers match, at least approximately, known subcompartments found in higher eukaryotic cells. ∼80% of assembly factors are essential. The number of copies of these assembly factors is comparable to the number of nascent transcripts. Moreover, they exhibit "isoelectric balance," with RNA-binding candidate "nucleator" assembly factors being notably basic. The physical properties of pre-small subunit and pre-large subunit assembly factors are similar, as are their 19 motif signatures detected by hierarchical clustering, unlike motif signatures of the 5'-external transcribed spacer rRNP. Additionally, many assembly factors lack shared motifs. Taken together with the progression of rRNP composition during subunit maturation, and the realization that the ribosomal DNA cable is initially bathed in a subunit-nonspecific assembly factor reservoir/microenvironment, we propose a "3-step subdomain assembly model": Step (1): predominantly basic assembly factors sequentially nucleate sites along nascent rRNA; Step (2): the resulting rRNPs recruit numerous less basic assembly factors along with notably basic ribosomal proteins; Step (3): rRNPs in nearby subdomains consolidate. Cleavages of rRNA then promote release of rRNPs to the nucleoplasm, likely facilitated by the persistence of assembly factors that were already associated with nucleolar precursors.
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Affiliation(s)
- Samantha Lin
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Suchita Rajan
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Sofia Lemberg
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Mark Altawil
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Katherine Anderson
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ruth Bryant
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Sebastian Cappeta
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Brandon Chin
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Isabella Hamdan
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Annelise Hamer
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Rachel Hyzny
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Andrew Karp
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Daniel Lee
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Alexandria Lim
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Medha Nayak
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Vishnu Palaniappan
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Soomin Park
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Sarika Satishkumar
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Anika Seth
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Uva Sri Dasari
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Emili Toppari
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ayush Vyas
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Julianne Walker
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Evan Weston
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Atif Zafar
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Cecelia Zielke
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ganapati H Mahabeleshwar
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Alan M Tartakoff
- Pathology Department and The Cell Biology Program, Case Western Reserve University, Cleveland, OH 44106, USA
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43
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Oborská-Oplová M, Gerhardy S, Panse VG. Orchestrating ribosomal RNA folding during ribosome assembly. Bioessays 2022; 44:e2200066. [PMID: 35751450 DOI: 10.1002/bies.202200066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/30/2022] [Accepted: 06/13/2022] [Indexed: 11/08/2022]
Abstract
Construction of the eukaryotic ribosome is a complex process in which a nascent ribosomal RNA (rRNA) emerging from RNA Polymerase I hierarchically folds into a native three-dimensional structure. Modular assembly of individual RNA domains through interactions with ribosomal proteins and a myriad of assembly factors permit efficient disentanglement of the error-prone RNA folding process. Following these dynamic events, long-range tertiary interactions are orchestrated to compact rRNA. A combination of genetic, biochemical, and structural studies is now providing clues into how a nascent rRNA is transformed into a functional ribosome with high precision. With this essay, we aim to draw attention to the poorly understood process of establishing correct RNA tertiary contacts during ribosome formation.
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Affiliation(s)
| | - Stefan Gerhardy
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Vikram Govind Panse
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.,Faculty of Science, University of Zurich, Zurich, Switzerland
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44
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Micic J, Rodríguez-Galán O, Babiano R, Fitzgerald F, Fernández-Fernández J, Zhang Y, Gao N, Woolford JL, de la Cruz J. Ribosomal protein eL39 is important for maturation of the nascent polypeptide exit tunnel and proper protein folding during translation. Nucleic Acids Res 2022; 50:6453-6473. [PMID: 35639884 PMCID: PMC9226512 DOI: 10.1093/nar/gkac366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/04/2022] [Accepted: 05/12/2022] [Indexed: 11/29/2022] Open
Abstract
During translation, nascent polypeptide chains travel from the peptidyl transferase center through the nascent polypeptide exit tunnel (NPET) to emerge from 60S subunits. The NPET includes portions of five of the six 25S/5.8S rRNA domains and ribosomal proteins uL4, uL22, and eL39. Internal loops of uL4 and uL22 form the constriction sites of the NPET and are important for both assembly and function of ribosomes. Here, we investigated the roles of eL39 in tunnel construction, 60S biogenesis, and protein synthesis. We show that eL39 is important for proper protein folding during translation. Consistent with a delay in processing of 27S and 7S pre-rRNAs, eL39 functions in pre-60S assembly during middle nucleolar stages. Our biochemical assays suggest the presence of eL39 in particles at these stages, although it is not visualized in them by cryo-electron microscopy. This indicates that eL39 takes part in assembly even when it is not fully accommodated into the body of pre-60S particles. eL39 is also important for later steps of assembly, rotation of the 5S ribonucleoprotein complex, likely through long range rRNA interactions. Finally, our data strongly suggest the presence of alternative pathways of ribosome assembly, previously observed in the biogenesis of bacterial ribosomal subunits.
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Affiliation(s)
- Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Reyes Babiano
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Fiona Fitzgerald
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - José Fernández-Fernández
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
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45
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Transcriptomic analysis of ribosome biogenesis and pre-rRNA processing during growth stress in Entamoeba histolytica. Exp Parasitol 2022; 239:108308. [PMID: 35718007 DOI: 10.1016/j.exppara.2022.108308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 05/27/2022] [Accepted: 06/14/2022] [Indexed: 11/24/2022]
Abstract
Ribosome biogenesis, a multi-step process involving transcription, modification, folding and processing of rRNA, is the major consumer of cellular energy. It involves sequential assembly of ribosomal proteins (RP)s via more than 200 ribogenesis factors. Unlike model organisms where transcription of rRNA and RP genes slows down during stress, in Entamoeba histolytica, pre-rRNA synthesis continues, and unprocessed pre-rRNA accumulates. Northern hybridization from different spacer regions depicted the accumulation of unprocessed intermediates during stress. To gain insight into the vast repertoire of ribosome biogenesis factors and understand the major components playing role during stress we computationally identified ribosome biogenesis factors in E. histolytica. Of the ∼279 Saccharomyces cerevisiae proteins, we could only find 188 proteins in E. histolytica. Some of the proteins missing in E. histolytica were also missing in humans. A number of proteins represented by multiple genes in S. cerevisiae had a single copy in E. histolytica. Interestingly E. histolytica lacked mitochondrial ribosome biogenesis factors and had far less RNase components compared to S. cerevisiae. Transcriptomic studies revealed the differential regulation of ribosomal factors both in serum starved and RRP6 down-regulation conditions. These included the NEP1 and TSR3 proteins that chemically modify 18S-rRNA. Pre-rRNA precursors accumulate upon downregulation of the latter proteins in S. cerevisiae and humans. These data reveal the major factors that regulate pre-rRNA processing during stress in E. histolytica and provide the first complete repertoire of ribosome biogenesis factors in this early-branching protist.
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46
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Tseng YT, Sung YC, Liu CY, Lo KY. Translation initiation factor eIF4G1 modulates assembly of the polypeptide exit tunnel region in yeast ribosome biogenesis. J Cell Sci 2022; 135:275526. [PMID: 35615984 DOI: 10.1242/jcs.259540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 05/12/2022] [Indexed: 01/24/2023] Open
Abstract
eIF4G is an important eukaryotic translation initiation factor. In this study, eIF4G1, one of the eIF4G isoforms, was shown to directly participate in biogenesis of the large (60S) ribosomal subunit in Saccharomyces cerevisiae cells. Mutation of eIF4G1 decreased the amount 60S ribosomal subunits significantly. The C-terminal fragment of eIF4G1 could complement the function in 60S biogenesis. Analyses of its purified complex with mass spectrometry indicated that eIF4G1 associated with the pre-60S form directly. Strong genetic and direct protein-protein interactions were observed between eIF4G1 and Ssf1 protein. Upon deletion of eIF4G1, Ssf1, Rrp15, Rrp14 and Mak16 were abnormally retained on the pre-60S complex. This purturbed the loading of Arx1 and eL31 at the polypeptide exit tunnel (PET) site and the transition to a Nog2 complex. Our data indicate that eIF4G1 is important in facilitating PET maturation and 27S processing correctly. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Yun-Ting Tseng
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Cheng Sung
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Ching-Yu Liu
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Kai-Yin Lo
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
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Matsuura-Suzuki E, Shimazu T, Takahashi M, Kotoshiba K, Suzuki T, Kashiwagi K, Sohtome Y, Akakabe M, Sodeoka M, Dohmae N, Ito T, Shinkai Y, Iwasaki S. METTL18-mediated histidine methylation of RPL3 modulates translation elongation for proteostasis maintenance. eLife 2022; 11:e72780. [PMID: 35674491 PMCID: PMC9177149 DOI: 10.7554/elife.72780] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 05/26/2022] [Indexed: 12/24/2022] Open
Abstract
Protein methylation occurs predominantly on lysine and arginine residues, but histidine also serves as a methylation substrate. However, a limited number of enzymes responsible for this modification have been reported. Moreover, the biological role of histidine methylation has remained poorly understood to date. Here, we report that human METTL18 is a histidine methyltransferase for the ribosomal protein RPL3 and that the modification specifically slows ribosome traversal on Tyr codons, allowing the proper folding of synthesized proteins. By performing an in vitro methylation assay with a methyl donor analog and quantitative mass spectrometry, we found that His245 of RPL3 is methylated at the τ-N position by METTL18. Structural comparison of the modified and unmodified ribosomes showed stoichiometric modification and suggested a role in translation reactions. Indeed, genome-wide ribosome profiling and an in vitro translation assay revealed that translation elongation at Tyr codons was suppressed by RPL3 methylation. Because the slower elongation provides enough time for nascent protein folding, RPL3 methylation protects cells from the cellular aggregation of Tyr-rich proteins. Our results reveal histidine methylation as an example of a ribosome modification that ensures proteome integrity in cells.
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Affiliation(s)
- Eriko Matsuura-Suzuki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Tadahiro Shimazu
- Cellular Memory Laboratory, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Mari Takahashi
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics ResearchYokohamaJapan
| | - Kaoru Kotoshiba
- Cellular Memory Laboratory, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, Technology Platform Division, RIKEN Center for Sustainable Resource ScienceSaitamaJapan
| | - Kazuhiro Kashiwagi
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics ResearchYokohamaJapan
| | - Yoshihiro Sohtome
- RIKEN Center for Sustainable Resource ScienceSaitamaJapan
- Synthetic Organic Chemistry Lab, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Mai Akakabe
- Synthetic Organic Chemistry Lab, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Mikiko Sodeoka
- RIKEN Center for Sustainable Resource ScienceSaitamaJapan
- Synthetic Organic Chemistry Lab, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, Technology Platform Division, RIKEN Center for Sustainable Resource ScienceSaitamaJapan
| | - Takuhiro Ito
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics ResearchYokohamaJapan
| | - Yoichi Shinkai
- Cellular Memory Laboratory, RIKEN Cluster for Pioneering ResearchSaitamaJapan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering ResearchSaitamaJapan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of TokyoChibaJapan
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48
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Bian Q, Li H, Wang X, Liang T, Zhang K. Multiomics Integrated Analysis Identifies SLC24A2 as a Potential Link between Type 2 Diabetes and Cancer. J Diabetes Res 2022; 2022:4629419. [PMID: 35601016 PMCID: PMC9122708 DOI: 10.1155/2022/4629419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 04/11/2022] [Indexed: 11/24/2022] Open
Abstract
Background So far, type 2 diabetes (T2D) is considered as an independent risk factor for various cancers, but the underlying mechanism remains unclear. Methods. SLC24A2 was first identified as a key gene strongly associated with fasting plasma glucose (FPG). Then, overlapped differentially expressed genes (DEGs) between T2D verse control and SLC24A2-high verse SLC24A2-low were extracted and imported into weighted correlation network analysis. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis were used for functional enrichment analysis of DEGs. Least absolute shrinkage and selection operator was utilized to build a T2D prediction model. Timer and K-M plotters were employed to find the expression and prognosis of SLC24A2 in pan cancer. Results Interestingly, both DEGs between T2D verse control and SLC24A2-high verse SLC24A2-low enriched in cancer-related pathways. Moreover, a total of 3719 overlapped DEGs were divided into 8 functional modules. Grey module negatively correlated with T2D and FPG and was markedly involved in ribosome biogenesis. Ten SLC24A2-related genes (RRP36, RPF1, GRWD1, FBL, EXOSC5, BCCIP, UTP14A, TWISTNB, TBL3, and SKIV2L) were identified as hub genes, based on which the LASSO model accurately predicts the occurrence of T2D (AUC = 0.841). In addition, SLC24A2 was only expressed in islet β cells and showed abnormal expression in 17 kinds of cancers and significantly correlated with the prognosis of 10 kinds of cancers. Conclusion Taken together, SLC24A2 may link T2D and cancer by influencing the ribosome function of islet β cells and play different prognostic roles in different cancers.
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Affiliation(s)
- Qin Bian
- Department of Clinical Laboratory, Guangyuan Central Hospital, Guangyuan 628000, China
| | - Haijun Li
- Department of Clinical Laboratory, Guangyuan Central Hospital, Guangyuan 628000, China
| | - Xiaoyi Wang
- Department of Medical Imaging, Guangyuan Central Hospital, Guangyuan 628000, China
| | - Tingting Liang
- Department of Hospital-Acquired Infection Control, Guangyuan Central Hospital, Guangyuan 628000, China
| | - Kai Zhang
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200000, China
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Liu X, Huang H, Karbstein K. Using DMS-MaPseq to Uncover the Roles of DEAD-box Proteins in Ribosome Assembly. Methods 2022; 204:249-257. [PMID: 35550176 PMCID: PMC10152975 DOI: 10.1016/j.ymeth.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/27/2022] [Accepted: 05/05/2022] [Indexed: 12/20/2022] Open
Abstract
DMS (dimethylsulfate) is a time-tested chemical probe for nucleic acid secondary structure that has recently re-emerged as a powerful tool to study RNA structure and structural changes, by coupling it to high throughput sequencing techniques. This variant, termed DMS-MaPseq, allows for mapping of all RNAs in a cell at the same time. However, if an RNA adopts different structures, for example during the assembly of an RNA-protein complex, or as part of its functional cycle, then DMS-MaPseq cannot differentiate between these structures, and an ensemble average will be produced. This is especially challenging for long-lived RNAs, such as ribosomes, whose steady-state abundance far exceeds that of any assembly intermediates, rendering those inaccessible to DMS-MaPseq on total RNAs. These challenges can be overcome by purification of assembly intermediates stalled at specific assembly steps (or steps in the functional cycle), via a combination of affinity tags and mutants stalled at defined steps, and subsequent DMS probing of these intermediates. Interpretation of the differences in DMS accessibility is facilitated by additional structural information, e.g. from cryo-EM experiments, available for many functional RNAs. While this approach is generally useful for studying RNA folding or conformational changes within RNA-protein complexes, it can be particularly valuable for studying the role(s) of DEAD-box proteins, as these tend to lead to larger conformational rearrangements, often resulting from the release of an RNA-binding protein from a bound RNA. Here we provide an adaptation of the DMS-MaPseq protocol to study RNA conformational transitions during ribosome assembly, which addresses the challenges arising from the presence of many assembly intermediates, all at concentrations far below that of mature ribosomes. While this protocol was developed for the yeast S. cerevisiae, we anticipate that it should be readily transferable to other model organisms for which affinity purification has been established.
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50
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Cao X, Khitun A, Harold CM, Bryant CJ, Zheng SJ, Baserga SJ, Slavoff SA. Nascent alt-protein chemoproteomics reveals a pre-60S assembly checkpoint inhibitor. Nat Chem Biol 2022; 18:643-651. [PMID: 35393574 PMCID: PMC9423127 DOI: 10.1038/s41589-022-01003-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 02/25/2022] [Indexed: 12/29/2022]
Abstract
Many unannotated microproteins and alternative proteins (alt-proteins) are coencoded with canonical proteins, but few of their functions are known. Motivated by the hypothesis that alt-proteins undergoing regulated synthesis could play important cellular roles, we developed a chemoproteomic pipeline to identify nascent alt-proteins in human cells. We identified 22 actively translated alt-proteins or N-terminal extensions, one of which is post-transcriptionally upregulated by DNA damage stress. We further defined a nucleolar, cell-cycle-regulated alt-protein that negatively regulates assembly of the pre-60S ribosomal subunit (MINAS-60). Depletion of MINAS-60 increases the amount of cytoplasmic 60S ribosomal subunit, upregulating global protein synthesis and cell proliferation. Mechanistically, MINAS-60 represses the rate of late-stage pre-60S assembly and export to the cytoplasm. Together, these results implicate MINAS-60 as a potential checkpoint inhibitor of pre-60S assembly and demonstrate that chemoproteomics enables hypothesis generation for uncharacterized alt-proteins.
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Affiliation(s)
- Xiongwen Cao
- Department of Chemistry, Yale University, New Haven, CT, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Alexandra Khitun
- Department of Chemistry, Yale University, New Haven, CT, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Cecelia M Harold
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Carson J Bryant
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Shu-Jian Zheng
- Department of Chemistry, Yale University, New Haven, CT, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Susan J Baserga
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.,Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Sarah A Slavoff
- Department of Chemistry, Yale University, New Haven, CT, USA. .,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA. .,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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