1
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Sutjita P, Musalgaonkar S, Recchia-Rife J, Huang L, Xhemalce B, Johnson AW. The Ribosome Assembly Factor LSG1 Interacts with Vesicle-Associated Membrane Protein-Associated Proteins (VAPs). Mol Cell Biol 2024; 44:345-357. [PMID: 39133101 PMCID: PMC11376406 DOI: 10.1080/10985549.2024.2384600] [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: 02/29/2024] [Revised: 07/18/2024] [Accepted: 07/19/2024] [Indexed: 08/13/2024] Open
Abstract
LSG1 is a conserved GTPase involved in ribosome assembly. It is required for the eviction of the nuclear export adapter NMD3 from the pre-60S subunit in the cytoplasm. In human cells, LSG1 has also been shown to interact with vesicle-associated membrane protein-associated proteins (VAPs) that are found primarily on the endoplasmic reticulum. VAPs interact with a large host of proteins which contain FFAT motifs (two phenylalanines (FF) in an acidic tract) and are involved in many cellular functions including membrane traffic and regulation of lipid transport. Here, we show that human LSG1 binds to VAPs via a noncanonical FFAT-like motif. Deletion of this motif specifically disrupts the localization of LSG1 to the ER, without perturbing LSG1-dependent recycling of NMD3 in cells or modulation of LSG1 GTPase activity in vitro.
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Affiliation(s)
- Putri Sutjita
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, Texas, USA
| | | | - Jeffrey Recchia-Rife
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Lisa Huang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Blerta Xhemalce
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Arlen W Johnson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
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2
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Yeh MC, Hsu NH, Chu HY, Yang CH, Hsu PH, Chou CC, Shie JT, Lee WM, Ho MC, Lo KY. Dual protection by Bcp1 and Rkm1 ensures incorporation of uL14 into pre-60S ribosomal subunits. J Cell Biol 2024; 223:e202306117. [PMID: 39007857 PMCID: PMC11248248 DOI: 10.1083/jcb.202306117] [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: 06/28/2023] [Revised: 02/13/2024] [Accepted: 04/19/2024] [Indexed: 07/16/2024] Open
Abstract
Eukaryotic ribosomal proteins contain extended regions essential for translation coordination. Dedicated chaperones stabilize the associated ribosomal proteins. We identified Bcp1 as the chaperone of uL14 in Saccharomyces cerevisiae. Rkm1, the lysine methyltransferase of uL14, forms a ternary complex with Bcp1 and uL14 to protect uL14. Rkm1 is transported with uL14 by importins to the nucleus, and Bcp1 disassembles Rkm1 and importin from uL14 simultaneously in a RanGTP-independent manner. Molecular docking, guided by crosslinking mass spectrometry and validated by a low-resolution cryo-EM map, reveals the correlation between Bcp1, Rkm1, and uL14, demonstrating the protection model. In addition, the ternary complex also serves as a surveillance point, whereas incorrect uL14 is retained on Rkm1 and prevented from loading to the pre-60S ribosomal subunits. This study reveals the molecular mechanism of how uL14 is protected and quality checked by serial steps to ensure its safe delivery from the cytoplasm until its incorporation into the 60S ribosomal subunit.
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Affiliation(s)
- Min-Chi Yeh
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Ning-Hsiang Hsu
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Hao-Yu Chu
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Pang-Hung Hsu
- Department of Bioscience and Biotechnology, College of Life Science, National Taiwan Ocean University, Keelung, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Chi-Chi Chou
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jing-Ting Shie
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Wei-Ming Lee
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kai-Yin Lo
- Department of Agricultural Chemistry, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
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3
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Song Y, Xue M, Wang F, Tang Q, Luo Y, Zheng M, Wang Y, Xue P, Dong N, Sun R, Fang M. Study on the Characteristics of Coarse Feeding Tolerance of Ding'an Pigs: Phenotypic and Candidate Genes Identification. Genes (Basel) 2024; 15:599. [PMID: 38790227 PMCID: PMC11121715 DOI: 10.3390/genes15050599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/28/2024] [Accepted: 05/03/2024] [Indexed: 05/26/2024] Open
Abstract
Ding'an (DA) pig, a prominent local breed in Hainan Province, exhibits notable advantages in coarse feeding tolerance and high-quality meat. To explore the potential genetic mechanism of coarse feeding tolerance in DA pigs, 60-day-old full sibling pairs of DA and DLY (Duroc-Landrace-Yorkshire) pigs were subjected to fed normal (5%) and high (10%) crude fiber diets for 56 days, respectively. The findings showed that increasing the crude fiber level had no impact on the apparent digestibility of crude fiber, intramuscular fat, and marbling scores in DA pigs, whereas these factors were significantly reduced in DLY pigs (p < 0.05). Through differential expression analysis and Weighted Gene Co-expression Network Analysis (WGCNA) of the colonic mucosal transcriptome data, 65 and 482 candidate genes with coarse feeding tolerance in DA pigs were identified, respectively. Joint analysis screened four key candidate genes, including LDHB, MLC1, LSG1, and ESM1, potentially serving as key regulated genes for coarse feeding tolerance. Functional analysis revealed that the most significant pathway enriched in differential genes associated with coarse feeding tolerance in Ding'an pigs was the signaling receptor binding. The results hold substantial significance for advancing our understanding of the genetic mechanisms governing coarse feeding tolerance in Ding'an pigs.
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Affiliation(s)
- Yanxia Song
- Sanya Institute of China Agricultural University, Sanya 572024, China; (Y.S.); (Y.W.); (N.D.)
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Mingming Xue
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Feng Wang
- Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Science, Haikou 571100, China; (F.W.); (R.S.)
| | - Qiguo Tang
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Yabiao Luo
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Meili Zheng
- Beijing General Station of Animal Husbandry, Beijing 100107, China;
| | - Yubei Wang
- Sanya Institute of China Agricultural University, Sanya 572024, China; (Y.S.); (Y.W.); (N.D.)
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Pengxiang Xue
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Ningqi Dong
- Sanya Institute of China Agricultural University, Sanya 572024, China; (Y.S.); (Y.W.); (N.D.)
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
| | - Ruiping Sun
- Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Science, Haikou 571100, China; (F.W.); (R.S.)
| | - Meiying Fang
- Sanya Institute of China Agricultural University, Sanya 572024, China; (Y.S.); (Y.W.); (N.D.)
- Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Key Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.X.); (Q.T.); (Y.L.); (P.X.)
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4
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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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5
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Li K, Zhang Q, Liu H, Wang F, Li A, Ding T, Mu Q, Zhao H, Wang P. Arabidopsis NOTCHLESS plays an important role in root and embryo development. PLANT SIGNALING & BEHAVIOR 2023; 18:2245616. [PMID: 37573563 PMCID: PMC10424599 DOI: 10.1080/15592324.2023.2245616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 08/15/2023]
Abstract
Ribosome biogenesis is a fundamental process in eukaryotic cells. NOTCHLESS (NLE) is involved in 60S ribosome biogenesis in yeast, but its role in Arabidopsis (A. thaliana) remains exclusive. Here, we found that Arabidopsis NLE (AtNLE) is highly conservative in phylogeny, which encoding a WD40-repeat protein. AtNLE is expressed in actively dividing tissues. AtNLE-GFP is localized in the nucleus. AtNLE physically interacts with the MIDAS domain of AtMDN1, a protein involved in the biogenesis of the 60S ribosomal subunit in Arabidopsis. The underexpressing mutant nle-2 shows short roots and reduced cell number in the root meristem. In addition, the null mutant nle-1 is embryo lethal, and defective embryos are arrested at the early globular stage. This work suggests that AtNLE interacts with AtMDN1, and AtNLE functions in root and embryo development.
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Affiliation(s)
- Ke Li
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Qingtian Zhang
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Huiping Liu
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Fengxia Wang
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Ao Li
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Tingting Ding
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
- Shandong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Jinan, China
| | - Qian Mu
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Hongjun Zhao
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
| | - Pengfei Wang
- Shandong Academy of Grape, Shandong Academy of Agricultural Sciences, Jinan, PR China
- Shandong Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Jinan, China
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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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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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8
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Musalgaonkar S, Yelland J, Chitale R, Rao S, Ozadam H, Cenik C, Taylor D, Johnson A. The Ribosome Assembly Factor Reh1 is Released from the Polypeptide Exit Tunnel in the Pioneer Round of Translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563604. [PMID: 37961559 PMCID: PMC10634756 DOI: 10.1101/2023.10.23.563604] [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
Assembly of functional ribosomal subunits and successfully delivering them to the translating pool is a prerequisite for protein synthesis and cell growth. In S. cerevisiae, the ribosome assembly factor Reh1 binds to pre-60S subunits at a late stage during their cytoplasmic maturation. Previous work shows that the C-terminus of Reh1 inserts into the polypeptide exit tunnel (PET) of the pre-60S subunit. Unlike canonical assembly factors, which associate exclusively with pre-60S subunits, we observed that Reh1 sediments with polysomes in addition to free 60S subunits. We therefore investigated the intriguing possibility that Reh1 remains associated with 60S subunits after the release of the anti-association factor Tif6 and after subunit joining. Here, we show that Reh1-bound nascent 60S subunits associate with 40S subunits to form actively translating ribosomes. Using selective ribosome profiling, we found that Reh1-bound ribosomes populate open reading frames near start codons. Reh1-bound ribosomes are also strongly enriched for initiator tRNA, indicating they are associated with early elongation events. Using single particle cryo-electron microscopy to image cycloheximide-arrested Reh1-bound 80S ribosomes, we found that Reh1-bound 80S contain A site peptidyl tRNA, P site tRNA and eIF5A indicating that Reh1 does not dissociate from 60S until early stages of translation elongation. We propose that Reh1 is displaced by the elongating peptide chain. These results identify Reh1 as the last assembly factor released from the nascent 60S subunit during its pioneer round of translation.
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9
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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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10
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Li Z, Chen S, Zhao L, Huang G, Xu H, Yang X, Wang P, Gao N, Sui SF. Nuclear export of pre-60S particles through the nuclear pore complex. Nature 2023:10.1038/s41586-023-06128-y. [PMID: 37258668 DOI: 10.1038/s41586-023-06128-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/25/2023] [Indexed: 06/02/2023]
Abstract
The nuclear pore complex (NPC) is the bidirectional gate that mediates the exchange of macromolecules or their assemblies between nucleus and cytoplasm1-3. The assembly intermediates of the ribosomal subunits, pre-60S and pre-40S particles, are among the largest cargoes of the NPC and the export of these gigantic ribonucleoproteins requires numerous export factors4,5. Here we report the cryo-electron microscopy structure of native pre-60S particles trapped in the channel of yeast NPCs. In addition to known assembly factors, multiple factors with export functions are also included in the structure. These factors in general bind to either the flexible regions or subunit interface of the pre-60S particle, and virtually form many anchor sites for NPC binding. Through interactions with phenylalanine-glycine (FG) repeats from various nucleoporins of NPC, these factors collectively facilitate the passage of the pre-60S particle through the central FG repeat network of the NPC. Moreover, in silico analysis of the axial and radial distribution of pre-60S particles within the NPC shows that a single NPC can take up to four pre-60S particles simultaneously, and pre-60S particles are enriched in the inner ring regions close to the wall of the NPC with the solvent-exposed surface facing the centre of the nuclear pore. Our data suggest a translocation model for the export of pre-60S particles through the NPC.
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Affiliation(s)
- Zongqiang Li
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Shuaijiabin Chen
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Liang Zhao
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Guoqiang Huang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Huiqin Xu
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Xiaoyun Yang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Peiyi Wang
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Sen-Fang Sui
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen, China.
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11
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Ikeuchi K, Ivic N, Buschauer R, Cheng J, Fröhlich T, Matsuo Y, Berninghausen O, Inada T, Becker T, Beckmann R. Molecular basis for recognition and deubiquitination of 40S ribosomes by Otu2. Nat Commun 2023; 14:2730. [PMID: 37169754 PMCID: PMC10175282 DOI: 10.1038/s41467-023-38161-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 04/19/2023] [Indexed: 05/13/2023] Open
Abstract
In actively translating 80S ribosomes the ribosomal protein eS7 of the 40S subunit is monoubiquitinated by the E3 ligase Not4 and deubiquitinated by Otu2 upon ribosomal subunit recycling. Despite its importance for translation efficiency the exact role and structural basis for this translational reset is poorly understood. Here, structural analysis by cryo-electron microscopy of native and reconstituted Otu2-bound ribosomal complexes reveals that Otu2 engages 40S subunits mainly between ribosome recycling and initiation stages. Otu2 binds to several sites on the intersubunit surface of the 40S that are not occupied by any other 40S-binding factors. This binding mode explains the discrimination against 80S ribosomes via the largely helical N-terminal domain of Otu2 as well as the specificity for mono-ubiquitinated eS7 on 40S. Collectively, this study reveals mechanistic insights into the Otu2-driven deubiquitination steps for translational reset during ribosome recycling/(re)initiation.
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Affiliation(s)
- Ken Ikeuchi
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Nives Ivic
- Division of Physical Chemistry, Rudjer Boskovic Institute, Bijenicka cesta 54, 10000, Zagreb, Croatia
| | - Robert Buschauer
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Jingdong Cheng
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
- Institutes of biomedical science, 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
| | - Thomas Fröhlich
- LAFUGA, Laboratory for Functional Genome Analysis, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Yoshitaka Matsuo
- Division of RNA and Gene Regulation, Institute of Medical Science, The University of Tokyo, Minato-ku, 108-8639, Japan
| | - Otto Berninghausen
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Toshifumi Inada
- Division of RNA and Gene Regulation, Institute of Medical Science, The University of Tokyo, Minato-ku, 108-8639, Japan
| | - Thomas Becker
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany.
| | - Roland Beckmann
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany.
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12
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Parker MD, Karbstein K. Quality control ensures fidelity in ribosome assembly and cellular health. J Cell Biol 2023; 222:e202209115. [PMID: 36790396 PMCID: PMC9960125 DOI: 10.1083/jcb.202209115] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [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
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13
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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: 43] [Impact Index Per Article: 43.0] [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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14
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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: 9] [Impact Index Per Article: 9.0] [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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15
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Murphy JC, Harrington EM, Schumann S, Vasconcelos EJR, Mottram TJ, Harper KL, Aspden JL, Whitehouse A. Kaposi's sarcoma-associated herpesvirus induces specialised ribosomes to efficiently translate viral lytic mRNAs. Nat Commun 2023; 14:300. [PMID: 36653366 PMCID: PMC9849454 DOI: 10.1038/s41467-023-35914-5] [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: 03/25/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023] Open
Abstract
Historically, ribosomes were viewed as unchanged homogeneous macromolecular machines with no regulatory capacity for mRNA translation. An emerging concept is that heterogeneity of ribosomal composition exists, exerting a regulatory function or specificity in translational control. This is supported by recent discoveries identifying compositionally distinct specialised ribosomes that actively regulate mRNA translation. Viruses lack their own translational machinery and impose high translational demands on the host during replication. We explore the possibility that KSHV manipulates ribosome biogenesis producing specialised ribosomes which preferentially translate viral transcripts. Quantitative proteomic analysis identified changes in the stoichiometry and composition of precursor ribosomal complexes during the switch from latent to lytic replication. We demonstrate the enhanced association of ribosomal biogenesis factors BUD23 and NOC4L, and the KSHV ORF11 protein, with small ribosomal subunit precursor complexes during lytic replication. BUD23 depletion resulted in significantly reduced viral gene expression, culminating in dramatic reduction of infectious virion production. Ribosome profiling demonstrated BUD23 is essential for reduced association of ribosomes with KSHV uORFs in late lytic genes, required for the efficient translation of the downstream coding sequence. Results provide mechanistic insights into KSHV-mediated manipulation of cellular ribosome composition inducing a population of specialised ribosomes facilitating efficient translation of viral mRNAs.
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Affiliation(s)
- James C Murphy
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Elena M Harrington
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Sophie Schumann
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | | | - Timothy J Mottram
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Katherine L Harper
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Julie L Aspden
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
- LeedsOmics, University of Leeds, Leeds, LS2 9JT, UK
| | - Adrian Whitehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
- LeedsOmics, University of Leeds, Leeds, LS2 9JT, UK.
- Department of Biochemistry & Microbiology, Rhodes University, Grahamstown, 6140, South Africa.
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16
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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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17
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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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18
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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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19
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Ismail S, Flemming D, Thoms M, Gomes-Filho JV, Randau L, Beckmann R, Hurt E. Emergence of the primordial pre-60S from the 90S pre-ribosome. Cell Rep 2022; 39:110640. [PMID: 35385737 PMCID: PMC8994135 DOI: 10.1016/j.celrep.2022.110640] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/01/2022] [Accepted: 03/16/2022] [Indexed: 01/03/2023] Open
Abstract
Synthesis of ribosomes begins in the nucleolus with formation of the 90S pre-ribosome, during which the pre-40S and pre-60S pathways diverge by pre-rRNA cleavage. However, it remains unclear how, after this uncoupling, the earliest pre-60S subunit continues to develop. Here, we reveal a large-subunit intermediate at the beginning of its construction when still linked to the 90S, the precursor to the 40S subunit. This primordial pre-60S is characterized by the SPOUT domain methyltransferase Upa1-Upa2, large α-solenoid scaffolds, Mak5, one of several RNA helicases, and two small nucleolar RNA (snoRNAs), C/D box snR190 and H/ACA box snR37. The emerging pre-60S does not efficiently disconnect from the 90S pre-ribosome in a dominant mak5 helicase mutant, allowing a 70-nm 90S-pre-60S bipartite particle to be visualized by electron microscopy. Our study provides insight into the assembly pathway when the still-connected nascent 40S and 60S subunits are beginning to separate.
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Affiliation(s)
- Sherif Ismail
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Matthias Thoms
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany
| | | | - Lennart Randau
- Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Roland Beckmann
- Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany.
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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20
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Huang H, Parker M, Karbstein K. The modifying enzyme Tsr3 establishes the hierarchy of Rio kinase binding in 40S ribosome assembly. RNA (NEW YORK, N.Y.) 2022; 28:568-582. [PMID: 35031584 PMCID: PMC8925970 DOI: 10.1261/rna.078994.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Ribosome assembly is an intricate process, which in eukaryotes is promoted by a large machinery comprised of over 200 assembly factors (AFs) that enable the modification, folding, and processing of the ribosomal RNA (rRNA) and the binding of the 79 ribosomal proteins. While some early assembly steps occur via parallel pathways, the process overall is highly hierarchical, which allows for the integration of maturation steps with quality control processes that ensure only fully and correctly assembled subunits are released into the translating pool. How exactly this hierarchy is established, in particular given that there are many instances of RNA substrate "handover" from one highly related AF to another, remains to be determined. Here we have investigated the role of Tsr3, which installs a universally conserved modification in the P-site of the small ribosomal subunit late in assembly. Our data demonstrate that Tsr3 separates the binding of the Rio kinases, Rio2 and Rio1, with whom it shares a binding site. By binding after Rio2 dissociation, Tsr3 prevents rebinding of Rio2, promoting forward assembly. After rRNA modification is complete, Tsr3 dissociates, thereby allowing for recruitment of Rio1 into its functional site. Inactive Tsr3 blocks Rio1 function, which can be rescued using mutants that bypass the requirement for Rio1 activity. Finally, yeast strains lacking Tsr3 randomize the binding of the two kinases, leading to the release of immature ribosomes into the translating pool. These data demonstrate a role for Tsr3 and its modification activity in establishing a hierarchy for the function of the Rio kinases.
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Affiliation(s)
- Haina Huang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences at Scripps Research, Jupiter, Florida 33458, USA
| | - Melissa Parker
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences at Scripps Research, Jupiter, Florida 33458, USA
| | - Katrin Karbstein
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, Jupiter, Florida 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences at Scripps Research, Jupiter, Florida 33458, USA
- HHMI Faculty Scholar, Chevy Chase, Maryland 20815, USA
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21
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Pulianmackal AJ, Kanakousaki K, Flegel K, Grushko OG, Gourley E, Rozich E, Buttitta LA. Misregulation of Nucleoporins 98 and 96 leads to defects in protein synthesis that promote hallmarks of tumorigenesis. Dis Model Mech 2022; 15:dmm049234. [PMID: 35107131 PMCID: PMC8938402 DOI: 10.1242/dmm.049234] [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: 08/03/2021] [Accepted: 01/15/2022] [Indexed: 11/20/2022] Open
Abstract
Nucleoporin 98KD (Nup98) is a promiscuous translocation partner in hematological malignancies. Most disease models of Nup98 translocations involve ectopic expression of the fusion protein under study, leaving the endogenous Nup98 loci unperturbed. Overlooked in these approaches is the loss of one copy of normal Nup98 in addition to the loss of Nup96 - a second Nucleoporin encoded within the same mRNA and reading frame as Nup98 - in translocations. Nup98 and Nup96 are also mutated in a number of other cancers, suggesting that their disruption is not limited to blood cancers. We found that reducing Nup98-96 function in Drosophila melanogaster (in which the Nup98-96 shared mRNA and reading frame is conserved) de-regulates the cell cycle. We found evidence of overproliferation in tissues with reduced Nup98-96, counteracted by elevated apoptosis and aberrant signaling associated with chronic wounding. Reducing Nup98-96 function led to defects in protein synthesis that triggered JNK signaling and contributed to hallmarks of tumorigenesis when apoptosis was inhibited. We suggest that partial loss of Nup98-96 function in translocations could de-regulate protein synthesis, leading to signaling that cooperates with other mutations to promote tumorigenesis.
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Affiliation(s)
| | | | | | | | | | | | - Laura A. Buttitta
- Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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22
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Mitterer V, Pertschy B. RNA folding and functions of RNA helicases in ribosome biogenesis. RNA Biol 2022; 19:781-810. [PMID: 35678541 PMCID: PMC9196750 DOI: 10.1080/15476286.2022.2079890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic ribosome biogenesis involves the synthesis of ribosomal RNA (rRNA) and its stepwise folding into the unique structure present in mature ribosomes. rRNA folding starts already co-transcriptionally in the nucleolus and continues when pre-ribosomal particles further maturate in the nucleolus and upon their transit to the nucleoplasm and cytoplasm. While the approximate order of folding of rRNA subdomains is known, especially from cryo-EM structures of pre-ribosomal particles, the actual mechanisms of rRNA folding are less well understood. Both small nucleolar RNAs (snoRNAs) and proteins have been implicated in rRNA folding. snoRNAs hybridize to precursor rRNAs (pre-rRNAs) and thereby prevent premature folding of the respective rRNA elements. Ribosomal proteins (r-proteins) and ribosome assembly factors might have a similar function by binding to rRNA elements and preventing their premature folding. Besides that, a small group of ribosome assembly factors are thought to play a more active role in rRNA folding. In particular, multiple RNA helicases participate in individual ribosome assembly steps, where they are believed to coordinate RNA folding/unfolding events or the release of proteins from the rRNA. In this review, we summarize the current knowledge on mechanisms of RNA folding and on the specific function of the individual RNA helicases involved. As the yeast Saccharomyces cerevisiae is the organism in which ribosome biogenesis and the role of RNA helicases in this process is best studied, we focused our review on insights from this model organism, but also make comparisons to other organisms where applicable.
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Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, Heidelberg, Germany
- BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, Graz, Austria
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23
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Oborská-Oplová M, Fischer U, Altvater M, Panse VG. Eukaryotic Ribosome assembly and Nucleocytoplasmic Transport. Methods Mol Biol 2022; 2533:99-126. [PMID: 35796985 PMCID: PMC9761919 DOI: 10.1007/978-1-0716-2501-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The process of eukaryotic ribosome assembly stretches across the nucleolus, the nucleoplasm and the cytoplasm, and therefore relies on efficient nucleocytoplasmic transport. In yeast, the import machinery delivers ~140,000 ribosomal proteins every minute to the nucleus for ribosome assembly. At the same time, the export machinery facilitates translocation of ~2000 pre-ribosomal particles every minute through ~200 nuclear pore complexes (NPC) into the cytoplasm. Eukaryotic ribosome assembly also requires >200 conserved assembly factors, which transiently associate with pre-ribosomal particles. Their site(s) of action on maturing pre-ribosomes are beginning to be elucidated. In this chapter, we outline protocols that enable rapid biochemical isolation of pre-ribosomal particles for single particle cryo-electron microscopy (cryo-EM) and in vitro reconstitution of nuclear transport processes. We discuss cell-biological and genetic approaches to investigate how the ribosome assembly and the nucleocytoplasmic transport machineries collaborate to produce functional ribosomes.
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Affiliation(s)
- Michaela Oborská-Oplová
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Ute Fischer
- Institute of Biochemistry, ETH 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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24
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Pöll G, Pilsl M, Griesenbeck J, Tschochner H, Milkereit P. Analysis of subunit folding contribution of three yeast large ribosomal subunit proteins required for stabilisation and processing of intermediate nuclear rRNA precursors. PLoS One 2021; 16:e0252497. [PMID: 34813592 PMCID: PMC8610266 DOI: 10.1371/journal.pone.0252497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/17/2021] [Indexed: 11/19/2022] Open
Abstract
In yeast and human cells many of the ribosomal proteins (r-proteins) are required for the stabilisation and productive processing of rRNA precursors. Functional coupling of r-protein assembly with the stabilisation and maturation of subunit precursors potentially promotes the production of ribosomes with defined composition. To further decipher mechanisms of such an intrinsic quality control pathway we analysed here the contribution of three yeast large ribosomal subunit r-proteins rpL2 (uL2), rpL25 (uL23) and rpL34 (eL34) for intermediate nuclear subunit folding steps. Structure models obtained from single particle cryo-electron microscopy analyses provided evidence for specific and hierarchic effects on the stable positioning and remodelling of large ribosomal subunit domains. Based on these structural and previous biochemical data we discuss possible mechanisms of r-protein dependent hierarchic domain arrangement and the resulting impact on the stability of misassembled subunits.
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Affiliation(s)
- Gisela Pöll
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Michael Pilsl
- Structural Biochemistry Unit, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
| | - Joachim Griesenbeck
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
| | - Herbert Tschochner
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
| | - Philipp Milkereit
- Chair of Biochemistry III, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany
- * E-mail: (JG); (HT); (PM)
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25
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Aquino GRR, Hackert P, Krogh N, Pan KT, Jaafar M, Henras AK, Nielsen H, Urlaub H, Bohnsack KE, Bohnsack MT. The RNA helicase Dbp7 promotes domain V/VI compaction and stabilization of inter-domain interactions during early 60S assembly. Nat Commun 2021; 12:6152. [PMID: 34686661 PMCID: PMC8536713 DOI: 10.1038/s41467-021-26208-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 09/22/2021] [Indexed: 02/07/2023] Open
Abstract
Early pre-60S ribosomal particles are poorly characterized, highly dynamic complexes that undergo extensive rRNA folding and compaction concomitant with assembly of ribosomal proteins and exchange of assembly factors. Pre-60S particles contain numerous RNA helicases, which are likely regulators of accurate and efficient formation of appropriate rRNA structures. Here we reveal binding of the RNA helicase Dbp7 to domain V/VI of early pre-60S particles in yeast and show that in the absence of this protein, dissociation of the Npa1 scaffolding complex, release of the snR190 folding chaperone, recruitment of the A3 cluster factors and binding of the ribosomal protein uL3 are impaired. uL3 is critical for formation of the peptidyltransferase center (PTC) and is responsible for stabilizing interactions between the 5′ and 3′ ends of the 25S, an essential pre-requisite for subsequent pre-60S maturation events. Highlighting the importance of pre-ribosome remodeling by Dbp7, our data suggest that in the absence of Dbp7 or its catalytic activity, early pre-ribosomal particles are targeted for degradation. Early steps of large 60S ribosomal subunit biogenesis are not well understood. Here, the authors combine biochemical experiments with protein-RNA crosslinking and mass spectrometry to show that the RNA helicase Dbp7 is key player during early 60S ribosomal assembly. Dbp7 regulates a series of events driving compaction of domain V/VI in early pre60S ribosomal particles.
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Affiliation(s)
- Gerald Ryan R Aquino
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark
| | - Kuan-Ting Pan
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Hematology/Oncology, Department of Medicine II, Johann Wolfgang Goethe University, 60590, Frankfurt am Main, Germany.,Frankfurt Cancer Institute, Goethe University, 60596, Frankfurt am Main, Germany
| | - Mariam Jaafar
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200N, Copenhagen, Denmark.,Genomics Group, Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry, 37077, Göttingen, Germany.,Institute for Clinical Chemistry, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany. .,Göttingen Centre for Molecular Biosciences, Georg-August-University, Justus-von-Liebig Weg 11, 37077, Göttingen, Germany.
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26
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Bagatelli FFM, de Luna Vitorino FN, da Cunha JPC, Oliveira CC. The ribosome assembly factor Nop53 has a structural role in the formation of nuclear pre-60S intermediates, affecting late maturation events. Nucleic Acids Res 2021; 49:7053-7074. [PMID: 34125911 PMCID: PMC8266606 DOI: 10.1093/nar/gkab494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 12/19/2022] Open
Abstract
Eukaryotic ribosome biogenesis is an elaborate process during which ribosomal proteins assemble with the pre-rRNA while it is being processed and folded. Hundreds of assembly factors (AF) are required and transiently recruited to assist the sequential remodeling events. One of the most intricate ones is the stepwise removal of the internal transcribed spacer 2 (ITS2), between the 5.8S and 25S rRNAs, that constitutes together with five AFs the pre-60S ‘foot’. In the transition from nucleolus to nucleoplasm, Nop53 replaces Erb1 at the basis of the foot and recruits the RNA exosome for the ITS2 cleavage and foot disassembly. Here we comprehensively analyze the impact of Nop53 recruitment on the pre-60S compositional changes. We show that depletion of Nop53, different from nop53 mutants lacking the exosome-interacting motif, not only causes retention of the unprocessed foot in late pre-60S intermediates but also affects the transition from nucleolar state E particle to subsequent nuclear stages. Additionally, we reveal that Nop53 depletion causes the impairment of late maturation events such as Yvh1 recruitment. In light of recently described pre-60S cryo-EM structures, our results provide biochemical evidence for the structural role of Nop53 rearranging and stabilizing the foot interface to assist the Nog2 particle formation.
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Affiliation(s)
- Felipe F M Bagatelli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Francisca N de Luna Vitorino
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, SP 05503-900, Brazil.,Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, SP 05503-900, Brazil
| | - Julia P C da Cunha
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, SP 05503-900, Brazil.,Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, SP 05503-900, Brazil
| | - Carla C Oliveira
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP 05508-000, Brazil
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27
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Biallelic splicing variants in the nucleolar 60S assembly factor RBM28 cause the ribosomopathy ANE syndrome. Proc Natl Acad Sci U S A 2021; 118:2017777118. [PMID: 33941690 PMCID: PMC8126767 DOI: 10.1073/pnas.2017777118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Alopecia, neurologic defects, and endocrinopathy (ANE) syndrome is a rare ribosomopathy known to be caused by a p.(Leu351Pro) variant in the essential, conserved, nucleolar large ribosomal subunit (60S) assembly factor RBM28. We report the second family of ANE syndrome to date and a female pediatric ANE syndrome patient. The patient presented with alopecia, craniofacial malformations, hypoplastic pituitary, and hair and skin abnormalities. Unlike the previously reported patients with the p.(Leu351Pro) RBM28 variant, this ANE syndrome patient possesses biallelic precursor messenger RNA (pre-mRNA) splicing variants at the 5' splice sites of exon 5 (ΔE5) and exon 8 (ΔE8) of RBM28 (NM_018077.2:c.[541+1_541+2delinsA]; [946G > T]). In silico analyses and minigene splicing experiments in cells indicate that each splice variant specifically causes skipping of its respective mutant exon. Because the ΔE5 variant results in an in-frame 31 amino acid deletion (p.(Asp150_Lys180del)) in RBM28 while the ΔE8 variant leads to a premature stop codon in exon 9, we predicted that the ΔE5 variant would produce partially functional RBM28 but the ΔE8 variant would not produce functional protein. Using a yeast model, we demonstrate that the ΔE5 variant does indeed lead to reduced overall growth and large subunit ribosomal RNA (rRNA) production and pre-rRNA processing. In contrast, the ΔE8 variant is comparably null, implying that the partially functional ΔE5 RBM28 protein enables survival but precludes correct development. This discovery further defines the underlying molecular pathology of ANE syndrome to include genetic variants that cause aberrant splicing in RBM28 pre-mRNA and highlights the centrality of nucleolar processes in human genetic disease.
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28
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Lv K, Gong C, Antony C, Han X, Ren JG, Donaghy R, Cheng Y, Pellegrino S, Warren AJ, Paralkar VR, Tong W. HectD1 controls hematopoietic stem cell regeneration by coordinating ribosome assembly and protein synthesis. Cell Stem Cell 2021; 28:1275-1290.e9. [PMID: 33711283 DOI: 10.1016/j.stem.2021.02.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/28/2020] [Accepted: 02/05/2021] [Indexed: 01/28/2023]
Abstract
Impaired ribosome function is the underlying etiology in a group of bone marrow failure syndromes called ribosomopathies. However, how ribosomes are regulated remains poorly understood, as are approaches to restore hematopoietic stem cell (HSC) function loss because of defective ribosome biogenesis. Here we reveal a role of the E3 ubiquitin ligase HectD1 in regulating HSC function via ribosome assembly and protein translation. Hectd1-deficient HSCs exhibit a striking defect in transplantation ability and ex vivo maintenance concomitant with reduced protein synthesis and growth rate under stress conditions. Mechanistically, HectD1 ubiquitinates and degrades ZNF622, an assembly factor for the ribosomal 60S subunit. Hectd1 loss leads to accumulation of ZNF622 and the anti-association factor eIF6 on 60S, resulting in 60S/40S joining defects. Importantly, Znf622 depletion in Hectd1-deficient HSCs restored ribosomal subunit joining, protein synthesis, and HSC reconstitution capacity. These findings highlight the importance of ubiquitin-coordinated ribosome assembly in HSC regeneration.
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Affiliation(s)
- Kaosheng Lv
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chujie Gong
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charles Antony
- Division of Hematology-Oncology, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xu Han
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jian-Gang Ren
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ryan Donaghy
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ying Cheng
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Simone Pellegrino
- Cambridge Institute for Medical Research, Cambridge, UK; Department of Haematology, University of Cambridge, Cambridge, UK; Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Alan J Warren
- Cambridge Institute for Medical Research, Cambridge, UK; Department of Haematology, University of Cambridge, Cambridge, UK; Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Vikram R Paralkar
- Division of Hematology-Oncology, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wei Tong
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Division of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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29
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Mechanisms and regulation of protein synthesis in mitochondria. Nat Rev Mol Cell Biol 2021; 22:307-325. [PMID: 33594280 DOI: 10.1038/s41580-021-00332-2] [Citation(s) in RCA: 159] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 02/06/2023]
Abstract
Mitochondria are cellular organelles responsible for generation of chemical energy in the process called oxidative phosphorylation. They originate from a bacterial ancestor and maintain their own genome, which is expressed by designated, mitochondrial transcription and translation machineries that differ from those operating for nuclear gene expression. In particular, the mitochondrial protein synthesis machinery is structurally and functionally very different from that governing eukaryotic, cytosolic translation. Despite harbouring their own genetic information, mitochondria are far from being independent of the rest of the cell and, conversely, cellular fitness is closely linked to mitochondrial function. Mitochondria depend heavily on the import of nuclear-encoded proteins for gene expression and function, and hence engage in extensive inter-compartmental crosstalk to regulate their proteome. This connectivity allows mitochondria to adapt to changes in cellular conditions and also mediates responses to stress and mitochondrial dysfunction. With a focus on mammals and yeast, we review fundamental insights that have been made into the biogenesis, architecture and mechanisms of the mitochondrial translation apparatus in the past years owing to the emergence of numerous near-atomic structures and a considerable amount of biochemical work. Moreover, we discuss how cellular mitochondrial protein expression is regulated, including aspects of mRNA and tRNA maturation and stability, roles of auxiliary factors, such as translation regulators, that adapt mitochondrial translation rates, and the importance of inter-compartmental crosstalk with nuclear gene expression and cytosolic translation and how it enables integration of mitochondrial translation into the cellular context.
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30
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Interaction Networks of Ribosomal Expansion Segments in Kinetoplastids. Subcell Biochem 2021; 96:433-450. [PMID: 33252739 DOI: 10.1007/978-3-030-58971-4_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Expansion segments (ES) are insertions of a few to hundreds of nucleotides at discrete locations on eukaryotic ribosomal RNA (rRNA) chains. Some cluster around 'hot spots' involved in translation regulation and some may participate in biogenesis. Whether ES play the same roles in different organisms is currently unclear, especially since their size may vary dramatically from one species to another and very little is known about their functions. Most likely, ES variation is linked to adaptation to a particular environment. In this chapter, we compare the interaction networks of ES from four kinetoplastid parasites, which have evolved in diverse insect vectors and mammalian hosts: Trypanosoma cruzi, Trypanosoma brucei, Leishmania donovani and Leishmania major. Here, we comparatively analyze ribosome structures from these representative kinetoplastids and ascertain meaningful structural differences from mammalian ribosomes. We base our analysis on sequence alignments and three-dimensional structures of 80S ribosomes solved by cryo-electron microscopy (cryo-EM). Striking differences in size are observed between ribosomes of different parasites, indicating that not all ES are expanded equally. Larger ES are not always matched by large surrounding ES or proteins extensions in their vicinity, a particularity that may lead to clues about their biological function. ES display different species-specific patterns of conservation, which underscore the density of their interaction network at the surface of the ribosome. Making sense of the conservation patterns of ES is part of a global effort to lay the basis for functional studies aimed at discovering unique kinetoplastid-specific sites suitable for therapeutic applications against these human and often animal pathogens.
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31
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Arabidopsis REI-LIKE proteins activate ribosome biogenesis during cold acclimation. Sci Rep 2021; 11:2410. [PMID: 33510206 PMCID: PMC7844247 DOI: 10.1038/s41598-021-81610-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/06/2021] [Indexed: 12/11/2022] Open
Abstract
Arabidopsis REIL proteins are cytosolic ribosomal 60S-biogenesis factors. After shift to 10 °C, reil mutants deplete and slowly replenish non-translating eukaryotic ribosome complexes of root tissue, while controlling the balance of non-translating 40S- and 60S-subunits. Reil mutations respond by hyper-accumulation of non-translating subunits at steady-state temperature; after cold-shift, a KCl-sensitive 80S sub-fraction remains depleted. We infer that Arabidopsis may buffer fluctuating translation by pre-existing non-translating ribosomes before de novo synthesis meets temperature-induced demands. Reil1 reil2 double mutants accumulate 43S-preinitiation and pre-60S-maturation complexes and alter paralog composition of ribosomal proteins in non-translating complexes. With few exceptions, e.g. RPL3B and RPL24C, these changes are not under transcriptional control. Our study suggests requirement of de novo synthesis of eukaryotic ribosomes for long-term cold acclimation, feedback control of NUC2 and eIF3C2 transcription and links new proteins, AT1G03250, AT5G60530, to plant ribosome biogenesis. We propose that Arabidopsis requires biosynthesis of specialized ribosomes for cold acclimation.
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32
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Ye C, Liu B, Lu H, Liu J, Rabson AB, Jacinto E, Pestov DG, Shen Z. BCCIP is required for nucleolar recruitment of eIF6 and 12S pre-rRNA production during 60S ribosome biogenesis. Nucleic Acids Res 2021; 48:12817-12832. [PMID: 33245766 PMCID: PMC7736804 DOI: 10.1093/nar/gkaa1114] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/28/2020] [Accepted: 11/05/2020] [Indexed: 01/25/2023] Open
Abstract
Ribosome biogenesis is a fundamental process required for cell proliferation. Although evolutionally conserved, the mammalian ribosome assembly system is more complex than in yeasts. BCCIP was originally identified as a BRCA2 and p21 interacting protein. A partial loss of BCCIP function was sufficient to trigger genomic instability and tumorigenesis. However, a complete deletion of BCCIP arrested cell growth and was lethal in mice. Here, we report that a fraction of mammalian BCCIP localizes in the nucleolus and regulates 60S ribosome biogenesis. Both abrogation of BCCIP nucleolar localization and impaired BCCIP-eIF6 interaction can compromise eIF6 recruitment to the nucleolus and 60S ribosome biogenesis. BCCIP is vital for a pre-rRNA processing step that produces 12S pre-rRNA, a precursor to the 5.8S rRNA. However, a heterozygous Bccip loss was insufficient to impair 60S biogenesis in mouse embryo fibroblasts, but a profound reduction of BCCIP was required to abrogate its function in 60S biogenesis. These results suggest that BCCIP is a critical factor for mammalian pre-rRNA processing and 60S generation and offer an explanation as to why a subtle dysfunction of BCCIP can be tumorigenic but a complete depletion of BCCIP is lethal.
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Affiliation(s)
- Caiyong Ye
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Bochao Liu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Huimei Lu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Jingmei Liu
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Arnold B Rabson
- Department of Pharmacology, and The Child Health Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Dimitri G Pestov
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Zhiyuan Shen
- Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Rutgers Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA
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33
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Structural insights into assembly of the ribosomal nascent polypeptide exit tunnel. Nat Commun 2020; 11:5111. [PMID: 33037216 PMCID: PMC7547690 DOI: 10.1038/s41467-020-18878-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 09/14/2020] [Indexed: 11/08/2022] Open
Abstract
The nascent polypeptide exit tunnel (NPET) is a major functional center of 60S ribosomal subunits. However, little is known about how the NPET is constructed during ribosome assembly. We utilized molecular genetics, biochemistry, and cryo-electron microscopy (cryo-EM) to investigate the functions of two NPET-associated proteins, ribosomal protein uL4 and assembly factor Nog1, in NPET assembly. Structures of mutant pre-ribosomes lacking the tunnel domain of uL4 reveal a misassembled NPET, including an aberrantly flexible ribosomal RNA helix 74, resulting in at least three different blocks in 60S assembly. Structures of pre-ribosomes lacking the C-terminal extension of Nog1 demonstrate that this extension scaffolds the tunnel domain of uL4 in the NPET to help maintain stability in the core of pre-60S subunits. Our data reveal that uL4 and Nog1 work together in the maturation of ribosomal RNA helix 74, which is required to ensure proper construction of the NPET and 60S ribosomal subunits. The nascent polypeptide exit tunnel (NPET) is a functional center of the large ribosomal subunit through which the nascent polypeptide chains travel from the peptidyltransferase center (PTC). Here the authors provide structural insight into NPET maturation and how it is linked to other aspects of ribosome biogenesis.
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34
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Olombrada M, Peña C, Rodríguez-Galán O, Klingauf-Nerurkar P, Portugal-Calisto D, Oborská-Oplová M, Altvater M, Gavilanes JG, Martínez-Del-Pozo Á, de la Cruz J, García-Ortega L, Panse VG. The ribotoxin α-sarcin can cleave the sarcin/ricin loop on late 60S pre-ribosomes. Nucleic Acids Res 2020; 48:6210-6222. [PMID: 32365182 PMCID: PMC7293039 DOI: 10.1093/nar/gkaa315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/27/2020] [Accepted: 04/20/2020] [Indexed: 12/11/2022] Open
Abstract
The ribotoxin α-sarcin belongs to a family of ribonucleases that cleave the sarcin/ricin loop (SRL), a critical functional rRNA element within the large ribosomal subunit (60S), thereby abolishing translation. Whether α-sarcin targets the SRL only in mature 60S subunits remains unresolved. Here, we show that, in yeast, α-sarcin can cleave SRLs within late 60S pre-ribosomes containing mature 25S rRNA but not nucleolar/nuclear 60S pre-ribosomes containing 27S pre-rRNA in vivo. Conditional expression of α-sarcin is lethal, but does not impede early pre-rRNA processing, nuclear export and the cytoplasmic maturation of 60S pre-ribosomes. Thus, SRL-cleaved containing late 60S pre-ribosomes seem to escape cytoplasmic proofreading steps. Polysome analyses revealed that SRL-cleaved 60S ribosomal subunits form 80S initiation complexes, but fail to progress to the step of translation elongation. We suggest that the functional integrity of a α-sarcin cleaved SRL might be assessed only during translation.
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Affiliation(s)
- Miriam Olombrada
- Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense de Madrid, Spain.,Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, CH-8093 Zürich, Switzerland
| | - Cohue Peña
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, CH-8093 Zürich, Switzerland.,Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, CH-8006 Zürich, Switzerland
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Purnima Klingauf-Nerurkar
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, CH-8093 Zürich, Switzerland.,Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, CH-8006 Zürich, Switzerland
| | - Daniela Portugal-Calisto
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, CH-8006 Zürich, Switzerland
| | - Michaela Oborská-Oplová
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, CH-8093 Zürich, Switzerland.,Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, CH-8006 Zürich, Switzerland
| | - Martin Altvater
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, CH-8093 Zürich, Switzerland
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense de Madrid, Spain
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense de Madrid, Spain
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Lucía García-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense de Madrid, Spain
| | - Vikram Govind Panse
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, CH-8006 Zürich, Switzerland
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35
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Jungers CF, Elliff JM, Masson-Meyers DS, Phiel CJ, Origanti S. Regulation of eukaryotic translation initiation factor 6 dynamics through multisite phosphorylation by GSK3. J Biol Chem 2020; 295:12796-12813. [PMID: 32703900 DOI: 10.1074/jbc.ra120.013324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/16/2020] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic translation initiation factor 6 (eIF6) is essential for the synthesis of 60S ribosomal subunits and for regulating the association of 60S and 40S subunits. A mechanistic understanding of how eIF6 modulates translation in response to stress, specifically starvation-induced stress, is lacking. We here show a novel mode of eIF6 regulation by glycogen synthase kinase 3 (GSK3) that is predominantly active in response to serum starvation. Both GSK3α and GSK3β phosphorylate human eIF6. Multiple residues in the C terminus of eIF6 are phosphorylated by GSK3 in a sequential manner. In response to serum starvation, eIF6 accumulates in the cytoplasm, and this altered localization depends on phosphorylation by GSK3. Disruption of eIF6 phosphorylation exacerbates the translation inhibitory response to serum starvation and stalls cell growth. These results suggest that eIF6 regulation by GSK3 contributes to the attenuation of global protein synthesis that is critical for adaptation to starvation-induced stress.
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Affiliation(s)
- Courtney F Jungers
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Jonah M Elliff
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | | | - Christopher J Phiel
- Department of Integrative Biology, University of Colorado Denver, Colorado, USA
| | - Sofia Origanti
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA .,Department of Biology, Saint Louis University, St. Louis, Missouri, USA
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36
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Micic J, Li Y, Wu S, Wilson D, Tutuncuoglu B, Gao N, Woolford JL. Coupling of 5S RNP rotation with maturation of functional centers during large ribosomal subunit assembly. Nat Commun 2020; 11:3751. [PMID: 32719344 PMCID: PMC7385084 DOI: 10.1038/s41467-020-17534-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 06/29/2020] [Indexed: 12/29/2022] Open
Abstract
The protein composition and structure of assembling 60S ribosomal subunits undergo numerous changes as pre-ribosomes transition from the nucleolus to the nucleoplasm. This includes stable anchoring of the Rpf2 subcomplex containing 5S rRNA, rpL5, rpL11, Rpf2 and Rrs1, which initially docks onto the flexible domain V of rRNA at earlier stages of assembly. In this work, we tested the function of the C-terminal domain (CTD) of Rpf2 during these anchoring steps, by truncating this extension and assaying effects on middle stages of subunit maturation. The rpf2Δ255-344 mutation affects proper folding of rRNA helices H68-70 during anchoring of the Rpf2 subcomplex. In addition, several assembly factors (AFs) are absent from pre-ribosomes or in altered conformations. Consequently, major remodeling events fail to occur: rotation of the 5S RNP, maturation of the peptidyl transferase center (PTC) and the nascent polypeptide exit tunnel (NPET), and export of assembling subunits to the cytoplasm. As assembling 60S subunits transit from the nucleolus to the nucleoplasm, they undergo significant changes in protein composition and structure. Here, the authors provide a structural view of interconnected events during the middle steps of assembly that include the maturation of the central protuberance, the peptidyltransferase center and the nascent polypeptide exit tunnel.
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Affiliation(s)
- Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Yu Li
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, Beijing, China.,Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, Beijing, China
| | - Shan Wu
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, Beijing, China.,State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, China
| | - Daniel Wilson
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Beril Tutuncuoglu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA.
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37
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Liang X, Zuo MQ, Zhang Y, Li N, Ma C, Dong MQ, Gao N. Structural snapshots of human pre-60S ribosomal particles before and after nuclear export. Nat Commun 2020; 11:3542. [PMID: 32669547 PMCID: PMC7363849 DOI: 10.1038/s41467-020-17237-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022] Open
Abstract
Ribosome biogenesis is an elaborate and energetically expensive program that involve two hundred protein factors in eukaryotes. Nuclear export of pre-ribosomal particles is one central step which also serves as an internal structural checkpoint to ensure the proper completion of nuclear assembly events. Here we present four structures of human pre-60S particles isolated through a nuclear export factor NMD3, representing assembly stages immediately before and after nuclear export. These structures reveal locations of a dozen of human factors, including an uncharacterized factor TMA16 localized between the 5S RNA and the P0 stalk. Comparison of these structures shows a progressive maturation for the functional regions, such as peptidyl transferase centre and peptide exit tunnel, and illustrate a sequence of factor-assisted rRNA maturation events. These data facilitate our understanding of the global conservation of ribosome assembly in eukaryotes and species-specific features of human assembly factors.
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MESH Headings
- Cell Nucleus/metabolism
- Cryoelectron Microscopy
- Humans
- Models, Molecular
- RNA, Ribosomal, 5S/isolation & purification
- RNA, Ribosomal, 5S/metabolism
- RNA, Ribosomal, 5S/ultrastructure
- RNA-Binding Proteins/isolation & purification
- RNA-Binding Proteins/metabolism
- RNA-Binding Proteins/ultrastructure
- Ribosomal Proteins/isolation & purification
- Ribosomal Proteins/metabolism
- Ribosomal Proteins/ultrastructure
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Large, Eukaryotic/ultrastructure
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Affiliation(s)
- Xiaomeng Liang
- State Key Laboratory of Membrane Biology, School of Life Science, Tsinghua University, 100084, Beijing, China
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Mei-Qing Zuo
- College of Biological Sciences, China Agricultural University, 100193, Beijing, China
- National Institute of Biological Sciences, 102206, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 100084, Beijing, China
| | - Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Chengying Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, 102206, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 100084, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, 100871, Beijing, China.
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38
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Firmino AAP, Gorka M, Graf A, Skirycz A, Martinez-Seidel F, Zander K, Kopka J, Beine-Golovchuk O. Separation and Paired Proteome Profiling of Plant Chloroplast and Cytoplasmic Ribosomes. PLANTS (BASEL, SWITZERLAND) 2020; 9:E892. [PMID: 32674508 PMCID: PMC7411607 DOI: 10.3390/plants9070892] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/24/2020] [Accepted: 07/09/2020] [Indexed: 12/14/2022]
Abstract
Conventional preparation methods of plant ribosomes fail to resolve non-translating chloroplast or cytoplasmic ribosome subunits from translating fractions. We established preparation of these ribosome complexes from Arabidopsis thaliana leaf, root, and seed tissues by optimized sucrose density gradient centrifugation of protease protected plant extracts. The method co-purified non-translating 30S and 40S ribosome subunits separated non-translating 50S from 60S subunits, and resolved assembled monosomes from low oligomeric polysomes. Combining ribosome fractionation with microfluidic rRNA analysis and proteomics, we characterized the rRNA and ribosomal protein (RP) composition. The identity of cytoplasmic and chloroplast ribosome complexes and the presence of ribosome biogenesis factors in the 60S-80S sedimentation interval were verified. In vivo cross-linking of leaf tissue stabilized ribosome biogenesis complexes, but induced polysome run-off. Omitting cross-linking, the established paired fractionation and proteome analysis monitored relative abundances of plant chloroplast and cytoplasmic ribosome fractions and enabled analysis of RP composition and ribosome associated proteins including transiently associated biogenesis factors.
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Affiliation(s)
- Alexandre Augusto Pereira Firmino
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Michal Gorka
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Alexander Graf
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Federico Martinez-Seidel
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kerstin Zander
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Joachim Kopka
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
| | - Olga Beine-Golovchuk
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; (M.G.); (A.G.); (A.S.); (F.M.-S.); (K.Z.); (J.K.); (O.B.-G.)
- Heidelberg University, Biochemie-Zentrum, Nuclear Pore Complex and Ribosome Assembly, 69120 Heidelberg, Germany
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39
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Kater L, Mitterer V, Thoms M, Cheng J, Berninghausen O, Beckmann R, Hurt E. Construction of the Central Protuberance and L1 Stalk during 60S Subunit Biogenesis. Mol Cell 2020; 79:615-628.e5. [PMID: 32668200 DOI: 10.1016/j.molcel.2020.06.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/13/2020] [Accepted: 06/18/2020] [Indexed: 12/15/2022]
Abstract
Ribosome assembly is driven by numerous assembly factors, including the Rix1 complex and the AAA ATPase Rea1. These two assembly factors catalyze 60S maturation at two distinct states, triggering poorly understood large-scale structural transitions that we analyzed by cryo-electron microscopy. Two nuclear pre-60S intermediates were discovered that represent previously unknown states after Rea1-mediated removal of the Ytm1-Erb1 complex and reveal how the L1 stalk develops from a pre-mature nucleolar to a mature-like nucleoplasmic state. A later pre-60S intermediate shows how the central protuberance arises, assisted by the nearby Rix1-Rea1 machinery, which was solved in its pre-ribosomal context to molecular resolution. This revealed a Rix12-Ipi32 tetramer anchored to the pre-60S via Ipi1, strategically positioned to monitor this decisive remodeling. These results are consistent with a general underlying principle that temporarily stabilized immature RNA domains are successively remodeled by assembly factors, thereby ensuring failsafe assembly progression.
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Affiliation(s)
- Lukas Kater
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Valentin Mitterer
- Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany
| | - Matthias Thoms
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany; Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany
| | - Jingdong Cheng
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Otto Berninghausen
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center Munich and Center of Integrated Protein Science-Munich (CiPS-M), Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany.
| | - Ed Hurt
- Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany.
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40
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Martinez-Seidel F, Beine-Golovchuk O, Hsieh YC, Kopka J. Systematic Review of Plant Ribosome Heterogeneity and Specialization. FRONTIERS IN PLANT SCIENCE 2020; 11:948. [PMID: 32670337 PMCID: PMC7332886 DOI: 10.3389/fpls.2020.00948] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 06/10/2020] [Indexed: 05/25/2023]
Abstract
Plants dedicate a high amount of energy and resources to the production of ribosomes. Historically, these multi-protein ribosome complexes have been considered static protein synthesis machines that are not subject to extensive regulation but only read mRNA and produce polypeptides accordingly. New and increasing evidence across various model organisms demonstrated the heterogeneous nature of ribosomes. This heterogeneity can constitute specialized ribosomes that regulate mRNA translation and control protein synthesis. A prominent example of ribosome heterogeneity is seen in the model plant, Arabidopsis thaliana, which, due to genome duplications, has multiple paralogs of each ribosomal protein (RP) gene. We support the notion of plant evolution directing high RP paralog divergence toward functional heterogeneity, underpinned in part by a vast resource of ribosome mutants that suggest specialization extends beyond the pleiotropic effects of single structural RPs or RP paralogs. Thus, Arabidopsis is a highly suitable model to study this phenomenon. Arabidopsis enables reverse genetics approaches that could provide evidence of ribosome specialization. In this review, we critically assess evidence of plant ribosome specialization and highlight steps along ribosome biogenesis in which heterogeneity may arise, filling the knowledge gaps in plant science by providing advanced insights from the human or yeast fields. We propose a data analysis pipeline that infers the heterogeneity of ribosome complexes and deviations from canonical structural compositions linked to stress events. This analysis pipeline can be extrapolated and enhanced by combination with other high-throughput methodologies, such as proteomics. Technologies, such as kinetic mass spectrometry and ribosome profiling, will be necessary to resolve the temporal and spatial aspects of translational regulation while the functional features of ribosomal subpopulations will become clear with the combination of reverse genetics and systems biology approaches.
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Affiliation(s)
- Federico Martinez-Seidel
- Willmitzer Department, Max Planck-Institute of Molecular Plant Physiology, Potsdam, Germany
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | | | - Yin-Chen Hsieh
- Bioinformatics Subdivision, Wageningen University, Wageningen, Netherlands
| | - Joachim Kopka
- Willmitzer Department, Max Planck-Institute of Molecular Plant Physiology, Potsdam, Germany
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41
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Abe T, Nagai R, Shimazaki S, Kondo S, Nishimura S, Sakaguchi Y, Suzuki T, Imataka H, Tomita K, Takeuchi-Tomita N. In vitro yeast reconstituted translation system reveals function of eIF5A for synthesis of long polypeptide. J Biochem 2020; 167:451-462. [PMID: 32053170 DOI: 10.1093/jb/mvaa022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 02/03/2020] [Indexed: 12/19/2022] Open
Abstract
We have recently developed an in vitro yeast reconstituted translation system, which is capable of synthesizing long polypeptides. Utilizing the system, we examined the role of eIF5A and its hypusine modification in translating polyproline sequence within long open reading frames. We found that polyproline motif inserted at the internal position of the protein arrests translation exclusively at low Mg2+ concentrations, and peptidylpolyproline-tRNA intrinsically destabilizes 80S ribosomes. We demonstrate that unmodified eIF5A essentially resolves such ribosome stalling; however, the hypusine modification drastically stimulates ability of eIF5A to rescue polyproline-mediated ribosome stalling and is particularly important for the efficient translation of the N-terminal or long internal polyproline motifs.
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Affiliation(s)
- Taisho Abe
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Riku Nagai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Shunta Shimazaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Shunta Kondo
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Satoshi Nishimura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroaki Imataka
- Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
| | - Kozo Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Nono Takeuchi-Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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42
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From Snapshots to Flipbook-Resolving the Dynamics of Ribosome Biogenesis with Chemical Probes. Int J Mol Sci 2020; 21:ijms21082998. [PMID: 32340379 PMCID: PMC7215809 DOI: 10.3390/ijms21082998] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 12/27/2022] Open
Abstract
The synthesis of ribosomes is one of the central and most resource demanding processes in each living cell. As ribosome biogenesis is tightly linked with the regulation of the cell cycle, perturbation of ribosome formation can trigger severe diseases, including cancer. Eukaryotic ribosome biogenesis starts in the nucleolus with pre-rRNA transcription and the initial assembly steps, continues in the nucleoplasm and is finished in the cytoplasm. From start to end, this process is highly dynamic and finished within few minutes. Despite the tremendous progress made during the last decade, the coordination of the individual maturation steps is hard to unravel by a conventional methodology. In recent years small molecular compounds were identified that specifically block either rDNA transcription or distinct steps within the maturation pathway. As these inhibitors diffuse into the cell rapidly and block their target proteins within seconds, they represent excellent tools to investigate ribosome biogenesis. Here we review how the inhibitors affect ribosome biogenesis and discuss how these effects can be interpreted by taking the complex self-regulatory mechanisms of the pathway into account. With this we want to highlight the potential of low molecular weight inhibitors to approach the dynamic nature of the ribosome biogenesis pathway.
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43
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Klingauf-Nerurkar P, Gillet LC, Portugal-Calisto D, Oborská-Oplová M, Jäger M, Schubert OT, Pisano A, Peña C, Rao S, Altvater M, Chang Y, Aebersold R, Panse VG. The GTPase Nog1 co-ordinates the assembly, maturation and quality control of distant ribosomal functional centers. eLife 2020; 9:e52474. [PMID: 31909713 PMCID: PMC6968927 DOI: 10.7554/elife.52474] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 12/20/2019] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic ribosome precursors acquire translation competence in the cytoplasm through stepwise release of bound assembly factors, and proofreading of their functional centers. In case of the pre-60S, these steps include removal of placeholders Rlp24, Arx1 and Mrt4 that prevent premature loading of the ribosomal protein eL24, the protein-folding machinery at the polypeptide exit tunnel (PET), and the ribosomal stalk, respectively. Here, we reveal that sequential ATPase and GTPase activities license release factors Rei1 and Yvh1 to trigger Arx1 and Mrt4 removal. Drg1-ATPase activity removes Rlp24 from the GTPase Nog1 on the pre-60S; consequently, the C-terminal tail of Nog1 is extracted from the PET. These events enable Rei1 to probe PET integrity and catalyze Arx1 release. Concomitantly, Nog1 eviction from the pre-60S permits peptidyl transferase center maturation, and allows Yvh1 to mediate Mrt4 release for stalk assembly. Thus, Nog1 co-ordinates the assembly, maturation and quality control of distant functional centers during ribosome formation.
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Affiliation(s)
| | - Ludovic C Gillet
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | | | - Michaela Oborská-Oplová
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Martin Jäger
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Olga T Schubert
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Agnese Pisano
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | - Cohue Peña
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | - Sanjana Rao
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
| | | | - Yiming Chang
- Institute of BiochemistryETH ZurichZurichSwitzerland
| | - Ruedi Aebersold
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Vikram G Panse
- Institute of Medical MicrobiologyUniversity of ZurichZurichSwitzerland
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44
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Abstract
In the past 25 years, genetic and biochemical analyses of ribosome assembly in yeast have identified most of the factors that participate in this complex pathway and have generated models for the mechanisms driving the assembly. More recently, the publication of numerous cryo-electron microscopy structures of yeast ribosome assembly intermediates has provided near-atomic resolution snapshots of ribosome precursor particles. Satisfyingly, these structural data support the genetic and biochemical models and provide additional mechanistic insight into ribosome assembly. In this Review, we discuss the mechanisms of assembly of the yeast small ribosomal subunit and large ribosomal subunit in the nucleolus, nucleus and cytoplasm. Particular emphasis is placed on concepts such as the mechanisms of RNA compaction, the functions of molecular switches and molecular mimicry, the irreversibility of assembly checkpoints and the roles of structural and functional proofreading of pre-ribosomal particles.
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45
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Tamm T, Kisly I, Remme J. Functional Interactions of Ribosomal Intersubunit Bridges in Saccharomyces cerevisiae. Genetics 2019; 213:1329-1339. [PMID: 31649153 PMCID: PMC6893367 DOI: 10.1534/genetics.119.302777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/22/2019] [Indexed: 01/02/2023] Open
Abstract
Ribosomes of Archaea and Eukarya share higher homology with each other than with bacterial ribosomes. For example, there is a set of 35 r-proteins that are specific only for archaeal and eukaryotic ribosomes. Three of these proteins-eL19, eL24, and eL41-participate in interactions between ribosomal subunits. The eukaryote-specific extensions of r-proteins eL19 and eL24 form two intersubunit bridges eB12 and eB13, which are present only in eukaryotic ribosomes. The third r-protein, eL41, forms bridge eB14. Notably, eL41 is found in all eukaryotes but only in some Archaea. It has been shown that bridges eB12 and eB13 are needed for efficient translation, while r-protein eL41 plays a minor role in ribosome function. Here, the functional interactions between intersubunit bridges were studied using budding yeast strains lacking different combinations of the abovementioned bridges/proteins. The growth phenotypes, levels of in vivo translation, ribosome-polysome profiles, and in vitro association of ribosomal subunits were analyzed. The results show a genetic interaction between r-protein eL41 and the eB12 bridge-forming region of eL19, and between r-proteins eL41 and eL24. It was possible to construct viable yeast strains with Archaea-like ribosomes lacking two or three eukaryote-specific bridges. These strains display slow growth and a poor translation phenotype. In addition, bridges eB12 and eB13 appear to cooperate during ribosome subunit association. These results indicate that nonessential structural elements of r-proteins become highly important in the context of disturbed subunit interactions. Therefore, eukaryote-specific bridges may contribute to the evolutionary success of eukaryotic translation machinery.
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Affiliation(s)
- Tiina Tamm
- Department of Molecular Biology, Institute of Molecular and Cell Biology, University of Tartu, 51010 Estonia
| | - Ivan Kisly
- Department of Molecular Biology, Institute of Molecular and Cell Biology, University of Tartu, 51010 Estonia
| | - Jaanus Remme
- Department of Molecular Biology, Institute of Molecular and Cell Biology, University of Tartu, 51010 Estonia
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46
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Musalgaonkar S, Black JJ, Johnson AW. The L1 stalk is required for efficient export of nascent large ribosomal subunits in yeast. RNA (NEW YORK, N.Y.) 2019; 25:1549-1560. [PMID: 31439809 PMCID: PMC6795138 DOI: 10.1261/rna.071811.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/08/2019] [Indexed: 06/02/2023]
Abstract
The ribosomal protein Rpl1 (uL1 in universal nomenclature) is essential in yeast and constitutes part of the L1 stalk which interacts with E site ligands on the ribosome. Structural studies of nascent pre-60S complexes in yeast have shown that a domain of the Crm1-dependent nuclear export adapter Nmd3, binds in the E site and interacts with Rpl1, inducing closure of the L1 stalk. Based on this observation, we decided to reinvestigate the role of the L1 stalk in nuclear export of pre-60S subunits despite previous work showing that Rpl1-deficient ribosomes are exported from the nucleus and engage in translation. Large cargoes, such as ribosomal subunits, require multiple export factors to facilitate their transport through the nuclear pore complex. Here, we show that pre-60S subunits lacking Rpl1 or truncated for the RNA of the L1 stalk are exported inefficiently. Surprisingly, this is not due to a measurable defect in the recruitment of Nmd3 but appears to result from inefficient recruitment of the Mex67-Mtr2 heterodimer.
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Affiliation(s)
- Sharmishtha Musalgaonkar
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Joshua J Black
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Arlen W Johnson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA
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47
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Correll CC, Bartek J, Dundr M. The Nucleolus: A Multiphase Condensate Balancing Ribosome Synthesis and Translational Capacity in Health, Aging and Ribosomopathies. Cells 2019; 8:cells8080869. [PMID: 31405125 PMCID: PMC6721831 DOI: 10.3390/cells8080869] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/31/2019] [Accepted: 08/06/2019] [Indexed: 12/21/2022] Open
Abstract
The nucleolus is the largest membrane-less structure in the eukaryotic nucleus. It is involved in the biogenesis of ribosomes, essential macromolecular machines responsible for synthesizing all proteins required by the cell. The assembly of ribosomes is evolutionarily conserved and is the most energy-consuming cellular process needed for cell growth, proliferation, and homeostasis. Despite the significance of this process, the intricate pathophysiological relationship between the nucleolus and protein synthesis has only recently begun to emerge. Here, we provide perspective on new principles governing nucleolar formation and the resulting multiphase organization driven by liquid-liquid phase separation. With recent advances in the structural analysis of ribosome formation, we highlight the current understanding of the step-wise assembly of pre-ribosomal subunits and the quality control required for proper function. Finally, we address how aging affects ribosome genesis and how genetic defects in ribosome formation cause ribosomopathies, complex diseases with a predisposition to cancer.
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Affiliation(s)
- Carl C Correll
- Center for Proteomics and Molecular Therapeutics, Rosalind Franklin University of Medicine & Science, North Chicago, IL 60064, USA.
| | - Jiri Bartek
- Danish Cancer Society Research Center, Genome Integrity Unit, DK-2100 Copenhagen, Denmark
- Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Science for Life Laboratory, Karolinska Institute, SE-171 77 Stockholm, Sweden
| | - Miroslav Dundr
- Center for Cancer Cell Biology Immunology and Infection, Rosalind Franklin University of Medicine & Science, North Chicago, IL 60064, USA.
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48
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Pantazi A, Quintanilla A, Hari P, Tarrats N, Parasyraki E, Dix FL, Patel J, Chandra T, Acosta JC, Finch AJ. Inhibition of the 60S ribosome biogenesis GTPase LSG1 causes endoplasmic reticular disruption and cellular senescence. Aging Cell 2019; 18:e12981. [PMID: 31148378 PMCID: PMC6612703 DOI: 10.1111/acel.12981] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 04/06/2019] [Accepted: 04/28/2019] [Indexed: 01/07/2023] Open
Abstract
Cellular senescence is triggered by diverse stimuli and is characterized by long-term growth arrest and secretion of cytokines and chemokines (termed the SASP-senescence-associated secretory phenotype). Senescence can be organismally beneficial as it can prevent the propagation of damaged or mutated clones and stimulate their clearance by immune cells. However, it has recently become clear that senescence also contributes to the pathophysiology of aging through the accumulation of damaged cells within tissues. Here, we describe that inhibition of the reaction catalysed by LSG1, a GTPase involved in the biogenesis of the 60S ribosomal subunit, leads to a robust induction of cellular senescence. Perhaps surprisingly, this was not due to ribosome depletion or translational insufficiency, but rather through perturbation of endoplasmic reticulum homeostasis and a dramatic upregulation of the cholesterol biosynthesis pathway. The underlying transcriptomic signature is shared with several other forms of senescence, and the cholesterol biosynthesis genes contribute to the cell cycle arrest in oncogene-induced senescence. Furthermore, targeting of LSG1 resulted in amplification of the cholesterol/ER signature and restoration of a robust cellular senescence response in transformed cells, suggesting potential therapeutic uses of LSG1 inhibition.
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Affiliation(s)
- Asimina Pantazi
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Andrea Quintanilla
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Priya Hari
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Nuria Tarrats
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Eleftheria Parasyraki
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Flora L. Dix
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Jaiyogesh Patel
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Tamir Chandra
- MRC Human Genetics Unit, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Juan Carlos Acosta
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Andrew J. Finch
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
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49
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Espinar-Marchena F, Rodríguez-Galán O, Fernández-Fernández J, Linnemann J, de la Cruz J. Ribosomal protein L14 contributes to the early assembly of 60S ribosomal subunits in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 46:4715-4732. [PMID: 29788267 PMCID: PMC5961077 DOI: 10.1093/nar/gky123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 02/12/2018] [Indexed: 12/11/2022] Open
Abstract
The contribution of most ribosomal proteins to ribosome synthesis has been quite well analysed in Saccharomyces cerevisiae. However, few yeast ribosomal proteins still await characterization. Herein, we show that L14, an essential 60S ribosomal protein, assembles in the nucleolus at an early stage into pre-60S particles. Depletion of L14 results in a deficit in 60S subunits and defective processing of 27SA2 and 27SA3 to 27SB pre-rRNAs. As a result, 27S pre-rRNAs are subjected to turnover and export of pre-60S particles is blocked. These phenotypes likely appear as the direct consequence of the reduced pre-60S particle association not only of L14 upon its depletion but also of a set of neighboring ribosomal proteins located at the solvent interface of 60S subunits and the adjacent region surrounding the polypeptide exit tunnel. These pre-60S intermediates also lack some essential trans-acting factors required for 27SB pre-rRNA processing but accumulate practically all factors required for processing of 27SA3 pre-rRNA. We have also analysed the functional interaction between the eukaryote-specific carboxy-terminal extensions of the neighboring L14 and L16 proteins. Our results indicate that removal of the most distal parts of these extensions cause slight translation alterations in mature 60S subunits.
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Affiliation(s)
- Francisco Espinar-Marchena
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, Seville, Spain. Avda. Manuel Siurot, E-41013 Seville, Spain
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, Seville, Spain. Avda. Manuel Siurot, E-41013 Seville, Spain
| | - José Fernández-Fernández
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, Seville, Spain. Avda. Manuel Siurot, E-41013 Seville, Spain
| | - Jan Linnemann
- Institut für Biochemie III, Universität Regensburg, 93053, Regensburg, Germany
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, Seville, Spain. Avda. Manuel Siurot, E-41013 Seville, Spain
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50
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Kargas V, Castro-Hartmann P, Escudero-Urquijo N, Dent K, Hilcenko C, Sailer C, Zisser G, Marques-Carvalho MJ, Pellegrino S, Wawiórka L, Freund SMV, Wagstaff JL, Andreeva A, Faille A, Chen E, Stengel F, Bergler H, Warren AJ. Mechanism of completion of peptidyltransferase centre assembly in eukaryotes. eLife 2019; 8:e44904. [PMID: 31115337 PMCID: PMC6579518 DOI: 10.7554/elife.44904] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/20/2019] [Indexed: 01/05/2023] Open
Abstract
During their final maturation in the cytoplasm, pre-60S ribosomal particles are converted to translation-competent large ribosomal subunits. Here, we present the mechanism of peptidyltransferase centre (PTC) completion that explains how integration of the last ribosomal proteins is coupled to release of the nuclear export adaptor Nmd3. Single-particle cryo-EM reveals that eL40 recruitment stabilises helix 89 to form the uL16 binding site. The loading of uL16 unhooks helix 38 from Nmd3 to adopt its mature conformation. In turn, partial retraction of the L1 stalk is coupled to a conformational switch in Nmd3 that allows the uL16 P-site loop to fully accommodate into the PTC where it competes with Nmd3 for an overlapping binding site (base A2971). Our data reveal how the central functional site of the ribosome is sculpted and suggest how the formation of translation-competent 60S subunits is disrupted in leukaemia-associated ribosomopathies.
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Affiliation(s)
- Vasileios Kargas
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Pablo Castro-Hartmann
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Norberto Escudero-Urquijo
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Kyle Dent
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Christine Hilcenko
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Carolin Sailer
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Gertrude Zisser
- Institute of Molecular BiosciencesUniversity of GrazGrazAustria
| | - Maria J Marques-Carvalho
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Simone Pellegrino
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Leszek Wawiórka
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
- Department of Molecular BiologyMaria Curie-Skłodowska UniversityLublinPoland
| | | | | | | | - Alexandre Faille
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Edwin Chen
- Faculty of Biological SciencesUniversity of LeedsLeedsUnited Kingdom
| | | | - Helmut Bergler
- Institute of Molecular BiosciencesUniversity of GrazGrazAustria
| | - Alan John Warren
- Cambridge Institute for Medical ResearchCambridgeUnited Kingdom
- Department of HaematologyUniversity of CambridgeCambridgeUnited Kingdom
- Wellcome Trust–Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
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