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Zakrzewska-Placzek M, Golisz-Mocydlarz A, Krzyszton M, Piotrowska J, Lichocka M, Kufel J. The nucleolar protein NOL12 is required for processing of large ribosomal subunit rRNA precursors in Arabidopsis. BMC PLANT BIOLOGY 2023; 23:538. [PMID: 37919659 PMCID: PMC10623804 DOI: 10.1186/s12870-023-04561-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
BACKGROUND NOL12 5'-3' exoribonucleases, conserved among eukaryotes, play important roles in pre-rRNA processing, ribosome assembly and export. The most well-described yeast counterpart, Rrp17, is required for maturation of 5.8 and 25S rRNAs, whereas human hNOL12 is crucial for the separation of the large (LSU) and small (SSU) ribosome subunit rRNA precursors. RESULTS In this study we demonstrate that plant AtNOL12 is also involved in rRNA biogenesis, specifically in the processing of the LSU rRNA precursor, 27S pre-rRNA. Importantly, the absence of AtNOL12 alters the expression of many ribosomal protein and ribosome biogenesis genes. These changes could potentially exacerbate rRNA biogenesis defects, or, conversely, they might stem from the disturbed ribosome assembly caused by delayed pre-rRNA processing. Moreover, exposure of the nol12 mutant to stress factors, including heat and pathogen Pseudomonas syringae, enhances the observed molecular phenotypes, linking pre-rRNA processing to stress response pathways. The aberrant rRNA processing, dependent on AtNOL12, could impact ribosome function, as suggested by improved mutant resistance to ribosome-targeting antibiotics. CONCLUSION Despite extensive studies, the pre-rRNA processing pathway in plants remains insufficiently characterized. Our investigation reveals the involvement of AtNOL12 in the maturation of rRNA precursors, correlating this process to stress response in Arabidopsis. These findings contribute to a more comprehensive understanding of plant ribosome biogenesis.
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Affiliation(s)
- Monika Zakrzewska-Placzek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw, 02-106, Poland.
| | - Anna Golisz-Mocydlarz
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw, 02-106, Poland
| | - Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw, 02-106, Poland
| | - Justyna Piotrowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw, 02-106, Poland
| | - Malgorzata Lichocka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw, 02-106, Poland
| | - Joanna Kufel
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, Warsaw, 02-106, Poland.
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2
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Genome-Wide Analysis of the Peptidase M24 Superfamily in Triticum aestivum Demonstrates That TaM24-9 Is Involved in Abiotic Stress Response. Int J Mol Sci 2022; 23:ijms23136904. [PMID: 35805912 PMCID: PMC9266489 DOI: 10.3390/ijms23136904] [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: 03/30/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 02/04/2023] Open
Abstract
The peptidase M24 (Metallopeptidase 24, M24) superfamily is essential for plant growth, stress response, and pathogen defense. At present, there are few systematic reports on the identification and classification of members of the peptidase M24 proteins superfamily in wheat. In this work, we identified 53 putative candidate TaM24 genes. According to the protein sequences characteristics, these members can be roughly divided into three subfamilies: I, II, III. Most TaM24 genes are complex with multiple exons, and the motifs are relatively conserved in each sub-group. Through chromosome mapping analysis, we found that the 53 genes were unevenly distributed on 19 wheat chromosomes (except 3A and 3D), of which 68% were in triads. Analysis of gene duplication events showed that 62% of TaM24 genes in wheat came from fragment duplication events, and there were no tandem duplication events to amplify genes. Analysis of the promoter sequences of TaM24 genes revealed that cis-acting elements were rich in response elements to drought, osmotic stress, ABA, and MeJA. We also studied the expression of TaM24 in wheat tissues at developmental stages and abiotic stress. Then we selected TaM24-9 as the target for further analysis. The results showed that TaM24-9 genes strengthened the drought and salt tolerance of plants. Overall, our analysis showed that members of the peptidase M24 genes may participate in the abiotic stress response and provided potential gene resources for improving wheat resistance.
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Hsu PJ, Tan MC, Shen HL, Chen YH, Wang YY, Hwang SG, Chiang MH, Le QV, Kuo WS, Chou YC, Lin SY, Jauh GY, Cheng WH. The nucleolar protein SAHY1 is involved in pre-rRNA processing and normal plant growth. PLANT PHYSIOLOGY 2021; 185:1039-1058. [PMID: 33793900 PMCID: PMC8133687 DOI: 10.1093/plphys/kiaa085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/01/2020] [Indexed: 05/29/2023]
Abstract
Although the nucleolus is involved in ribosome biogenesis, the functions of numerous nucleolus-localized proteins remain unclear. In this study, we genetically isolated Arabidopsis thaliana salt hypersensitive mutant 1 (sahy1), which exhibits slow growth, short roots, pointed leaves, and sterility. SAHY1 encodes an uncharacterized protein that is predominantly expressed in root tips, early developing seeds, and mature pollen grains and is mainly restricted to the nucleolus. Dysfunction of SAHY1 primarily causes the accumulation of 32S, 18S-A3, and 27SB pre-rRNA intermediates. Coimmunoprecipitation experiments further revealed the interaction of SAHY1 with ribosome proteins and ribosome biogenesis factors. Moreover, sahy1 mutants are less sensitive to protein translation inhibitors and show altered expression of structural constituents of ribosomal genes and ribosome subunit profiles, reflecting the involvement of SAHY1 in ribosome composition and ribosome biogenesis. Analyses of ploidy, S-phase cell cycle progression, and auxin transport and signaling indicated the impairment of mitotic activity, translation of auxin transport carrier proteins, and expression of the auxin-responsive marker DR5::GFP in the root tips or embryos of sahy1 plants. Collectively, these data demonstrate that SAHY1, a nucleolar protein involved in ribosome biogenesis, plays critical roles in normal plant growth in association with auxin transport and signaling.
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Affiliation(s)
- Pei-jung Hsu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Mei-Chen Tan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Hwei-Ling Shen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Ya-Huei Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Ya-Ying Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - San-Gwang Hwang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Ming-Hau Chiang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Quang-Vuong Le
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Wen-Shuo Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Ying-Chan Chou
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, Neipu, Pingtung County,Taiwan
| | - Shih-Yun Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Guang-Yuh Jauh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Wan-Hsing Cheng
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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4
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Jaramillo-Ramírez J, Marcial-Bazaldua N, Sánchez-Puig N. Characterisation of the interaction of guanine nucleotides with ribosomal GTPase Lsg1. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1869:140538. [PMID: 32916301 DOI: 10.1016/j.bbapap.2020.140538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 08/06/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
Ribosome biogenesis in eukaryotes requires the participation of several transactivation factors that are involved in the modification, assembly, transport and quality control of the ribosomal subunits. One of these factors is the Large subunit GTPase 1 (Lsg1), a protein that acts as the release factor for the export adaptor named Nonsense-mediated mRNA decay 3 protein (Nmd3) and facilitates the incorporation of the last structural protein uL16 into the 60S subunit. Here, we characterised the recombinant yeast Lsg1 and studied its catalysis and binding properties for guanine nucleotides. We described the interaction of Lsg1 with guanine nucleotides alone and in the presence of the complex Nmd3•60S using fluorescence spectroscopy. Lsg1 has a greater affinity for GTP than for GDP suggesting that in the cell cytoplasm it exists mainly bound to the former. In the presence of 60S subunits loaded with Nmd3, the affinity of Lsg1 for both nucleotides increases but to a larger extent towards GTP. From this observation together with the excess of GTP present in the cytoplasm of exponentially growing cells over that of GDP, we can infer that the pre-ribosomal particle composed by Nmd3•60S acts as a GTP Stabilising Factor for Lsg1. Additionally, Lsg1 undergoes different conformational changes depending on its binding partner or the guanine nucleotides it interacts with. Steady-state kinetic analysis of free Lsg1 indicated slow GTP hydrolysis with values of kcat 1 min-1 and Km of 34 μM.
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Affiliation(s)
- Juliana Jaramillo-Ramírez
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México 04510, Mexico
| | - Nancy Marcial-Bazaldua
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México 04510, Mexico
| | - Nuria Sánchez-Puig
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México 04510, Mexico..
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Sáez-Vásquez J, Delseny M. Ribosome Biogenesis in Plants: From Functional 45S Ribosomal DNA Organization to Ribosome Assembly Factors. THE PLANT CELL 2019; 31:1945-1967. [PMID: 31239391 PMCID: PMC6751116 DOI: 10.1105/tpc.18.00874] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/28/2019] [Accepted: 06/25/2019] [Indexed: 05/11/2023]
Abstract
The transcription of 18S, 5.8S, and 18S rRNA genes (45S rDNA), cotranscriptional processing of pre-rRNA, and assembly of mature rRNA with ribosomal proteins are the linchpins of ribosome biogenesis. In yeast (Saccharomyces cerevisiae) and animal cells, hundreds of pre-rRNA processing factors have been identified and their involvement in ribosome assembly determined. These studies, together with structural analyses, have yielded comprehensive models of the pre-40S and pre-60S ribosome subunits as well as the largest cotranscriptionally assembled preribosome particle: the 90S/small subunit processome. Here, we present the current knowledge of the functional organization of 45S rDNA, pre-rRNA transcription, rRNA processing activities, and ribosome assembly factors in plants, focusing on data from Arabidopsis (Arabidopsis thaliana). Based on yeast and mammalian cell studies, we describe the ribonucleoprotein complexes and RNA-associated activities and discuss how they might specifically affect the production of 40S and 60S subunits. Finally, we review recent findings concerning pre-rRNA processing pathways and a novel mechanism involved in a ribosome stress response in plants.
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Affiliation(s)
- Julio Sáez-Vásquez
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France, and Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
| | - Michel Delseny
- CNRS, Laboratoire Génome et Développement des Plantes, UMR 5096, 66860 Perpignan, France, and Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, UMR 5096, F-66860 Perpignan, France
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6
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Jeon Y, Ahn HK, Kang YW, Pai HS. Functional characterization of chloroplast-targeted RbgA GTPase in higher plants. PLANT MOLECULAR BIOLOGY 2017; 95:463-479. [PMID: 29038916 DOI: 10.1007/s11103-017-0664-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 10/01/2017] [Indexed: 06/07/2023]
Abstract
KEY MESSAGE Plant RbgA GTPase is targeted to chloroplasts and co-fractionated with chloroplast ribosomes, and plays a role in chloroplast rRNA processing and/or ribosome biogenesis. Ribosome Biogenesis GTPase A (RbgA) homologs are evolutionarily conserved GTPases that are widely distributed in both prokaryotes and eukaryotes. In this study, we investigated functions of chloroplast-targeted RbgA. Nicotiana benthamiana RbgA (NbRbgA) and Arabidopsis thaliana RbgA (AtRbgA) contained a conserved GTP-binding domain and a plant-specific C-terminal domain. NbRbgA and AtRbgA were mainly localized in chloroplasts, and possessed GTPase activity. Since Arabidopsis rbgA null mutants exhibited an embryonic lethal phenotype, virus-induced gene silencing (VIGS) of NbRbgA was performed in N. benthamiana. NbRbgA VIGS resulted in a leaf-yellowing phenotype caused by disrupted chloroplast development. NbRbgA was mainly co-fractionated with 50S/70S ribosomes and interacted with the chloroplast ribosomal proteins cpRPL6 and cpRPL35. NbRbgA deficiency lowered the levels of mature 23S and 16S rRNAs in chloroplasts and caused processing defects. Sucrose density gradient sedimentation revealed that NbRbgA-deficient chloroplasts contained reduced levels of mature 23S and 16S rRNAs and diverse plastid-encoded mRNAs in the polysomal fractions, suggesting decreased protein translation activity in the chloroplasts. Interestingly, NbRbgA protein was highly unstable under high light stress, suggesting its possible involvement in the control of chloroplast ribosome biogenesis under environmental stresses. Collectively, these results suggest a role for RbgA GTPase in chloroplast rRNA processing/ribosome biogenesis, affecting chloroplast protein translation in higher plants.
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Affiliation(s)
- Young Jeon
- Department of Systems Biology, Yonsei University, Seoul, 03722, South Korea
| | - Hee-Kyung Ahn
- Department of Systems Biology, Yonsei University, Seoul, 03722, South Korea
| | - Yong Won Kang
- R&D Center, Morechem Co., Ltd., Yongin, Gyeonggi-do, 16954, South Korea
| | - Hyun-Sook Pai
- Department of Systems Biology, Yonsei University, Seoul, 03722, South Korea.
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7
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RSM22, mtYsxC and PNKD-like proteins are required for mitochondrial translation in Trypanosoma brucei. Mitochondrion 2017; 34:67-74. [DOI: 10.1016/j.mito.2017.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 12/07/2016] [Accepted: 01/10/2017] [Indexed: 11/20/2022]
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8
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Weis BL, Kovacevic J, Missbach S, Schleiff E. Plant-Specific Features of Ribosome Biogenesis. TRENDS IN PLANT SCIENCE 2015; 20:729-740. [PMID: 26459664 DOI: 10.1016/j.tplants.2015.07.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 06/19/2015] [Accepted: 07/15/2015] [Indexed: 05/03/2023]
Abstract
The biogenesis of eukaryotic ribosomes is a fundamental process involving hundreds of ribosome biogenesis factors (RBFs) in three compartments of the cell, namely the nucleolus, nucleus, and cytoplasm. Many RBFs are involved in the processing of the primary ribosomal (r)RNA transcript, in which three of the four rRNAs are imbedded. While pre-rRNA processing is well described for yeast and mammals, a detailed processing scheme for plants is lacking. Here, we discuss the emerging scheme of pre-rRNA processing in Arabidopsis thaliana in comparison to other eukaryotes, with a focus on plant characteristics. In addition, we highlight the impact of the ribosome and its biogenesis on developmental processes because common phenotypes can be observed for ribosomal protein and RBF mutants.
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Affiliation(s)
- Benjamin L Weis
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Jelena Kovacevic
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Sandra Missbach
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany; Current address: Sanofi-Aventis GmbH, Industriepark Höchst, K703, 65926 Frankfurt am Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany; Cluster of Excellence Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany; Buchman Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany.
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9
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Zhao H, Lü S, Li R, Chen T, Zhang H, Cui P, Ding F, Liu P, Wang G, Xia Y, Running MP, Xiong L. The Arabidopsis gene DIG6 encodes a large 60S subunit nuclear export GTPase 1 that is involved in ribosome biogenesis and affects multiple auxin-regulated development processes. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6863-75. [PMID: 26272902 PMCID: PMC4623693 DOI: 10.1093/jxb/erv391] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The circularly permuted GTPase large subunit GTPase 1 (LSG1) is involved in the maturation step of the 60S ribosome and is essential for cell viability in yeast. Here, an Arabidopsis mutant dig6 (drought inhibited growth of lateral roots) was isolated. The mutant exhibited multiple auxin-related phenotypes, which included reduced lateral root number, altered leaf veins, and shorter roots. Genetic mapping combined with next-generation DNA sequencing identified that the mutation occurred in AtLSG1-2. This gene was highly expressed in regions of auxin accumulation. Ribosome profiling revealed that a loss of function of AtLSG1-2 led to decreased levels of monosomes, further demonstrating its role in ribosome biogenesis. Quantitative proteomics showed that the expression of certain proteins involved in ribosome biogenesis was differentially regulated, indicating that ribosome biogenesis processes were impaired in the mutant. Further investigations showed that an AtLSG1-2 deficiency caused the alteration of auxin distribution, response, and transport in plants. It is concluded that AtLSG1-2 is integral to ribosome biogenesis, consequently affecting auxin homeostasis and plant development.
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Affiliation(s)
- Huayan Zhao
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Shiyou Lü
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
| | - Ruixi Li
- Institute for Integrative Genome Biology, Center for Plant Cell Biology & Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Tao Chen
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Huoming Zhang
- Bioscience Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Peng Cui
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Feng Ding
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Pei Liu
- Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China
| | - Guangchao Wang
- Bioscience Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China
| | - Mark P Running
- Department of Biology, University of Louisville, Louisville, KY 40292, USA
| | - Liming Xiong
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
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10
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Jeon Y, Park YJ, Cho HK, Jung HJ, Ahn TK, Kang H, Pai HS. The nucleolar GTPase nucleostemin-like 1 plays a role in plant growth and senescence by modulating ribosome biogenesis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6297-310. [PMID: 26163696 PMCID: PMC4588883 DOI: 10.1093/jxb/erv337] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Nucleostemin is a nucleolar GTP-binding protein that is involved in stem cell proliferation, embryonic development, and ribosome biogenesis in mammals. Plant nucleostemin-like 1 (NSN1) plays a role in embryogenesis, and apical and floral meristem development. In this study, a nucleolar function of NSN1 in the regulation of ribosome biogenesis was identified. Green fluorescent protein (GFP)-fused NSN1 localized to the nucleolus, which was primarily determined by its N-terminal domain. Recombinant NSN1 and its N-terminal domain (NSN1-N) bound to RNA in vitro. Recombinant NSN1 expressed GTPase activity in vitro. NSN1 silencing in Arabidopsis thaliana and Nicotiana benthamiana led to growth retardation and premature senescence. NSN1 interacted with Pescadillo and EBNA1 binding protein 2 (EBP2), which are nucleolar proteins involved in ribosome biogenesis, and with several ribosomal proteins. NSN1, NSN1-N, and EBP2 co-fractionated primarily with the 60S ribosomal large subunit in vivo. Depletion of NSN1 delayed 25S rRNA maturation and biogenesis of the 60S ribosome subunit, and repressed global translation. NSN1-deficient plants exhibited premature leaf senescence, excessive accumulation of reactive oxygen species, and senescence-related gene expression. Taken together, these results suggest that NSN1 plays a crucial role in plant growth and senescence by modulating ribosome biogenesis.
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Affiliation(s)
- Young Jeon
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Yong-Joon Park
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Hui Kyung Cho
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Hyun Ju Jung
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea
| | - Tae-Kyu Ahn
- Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea
| | - Hunseung Kang
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea
| | - Hyun-Sook Pai
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
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11
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Simm S, Fragkostefanakis S, Paul P, Keller M, Einloft J, Scharf KD, Schleiff E. Identification and Expression Analysis of Ribosome Biogenesis Factor Co-orthologs in Solanum lycopersicum. Bioinform Biol Insights 2015; 9:1-17. [PMID: 25698879 PMCID: PMC4325683 DOI: 10.4137/bbi.s20751] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/17/2014] [Accepted: 11/21/2014] [Indexed: 12/12/2022] Open
Abstract
Ribosome biogenesis involves a large inventory of proteinaceous and RNA cofactors. More than 250 ribosome biogenesis factors (RBFs) have been described in yeast. These factors are involved in multiple aspects like rRNA processing, folding, and modification as well as in ribosomal protein (RP) assembly. Considering the importance of RBFs for particular developmental processes, we examined the complexity of RBF and RP (co-)orthologs by bioinformatic assignment in 14 different plant species and expression profiling in the model crop Solanum lycopersicum. Assigning (co-)orthologs to each RBF revealed that at least 25% of all predicted RBFs are encoded by more than one gene. At first we realized that the occurrence of multiple RBF co-orthologs is not globally correlated to the existence of multiple RP co-orthologs. The transcript abundance of genes coding for predicted RBFs and RPs in leaves and anthers of S. lycopersicum was determined by next generation sequencing (NGS). In combination with existing expression profiles, we can conclude that co-orthologs of RBFs by large account for a preferential function in different tissue or at distinct developmental stages. This notion is supported by the differential expression of selected RBFs during male gametophyte development. In addition, co-regulated clusters of RBF and RP coding genes have been observed. The relevance of these results is discussed.
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Affiliation(s)
- Stefan Simm
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Cluster of Excellence Frankfurt, Goethe University, Frankfurt/Main, Germany
| | - Sotirios Fragkostefanakis
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Cluster of Excellence Frankfurt, Goethe University, Frankfurt/Main, Germany
| | - Puneet Paul
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Mario Keller
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Jens Einloft
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Klaus-Dieter Scharf
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Center of Membrane Proteomics, Goethe University, Frankfurt/Main, Germany. ; Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt/Main, Germany
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12
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Weis BL, Missbach S, Marzi J, Bohnsack MT, Schleiff E. The 60S associated ribosome biogenesis factor LSG1-2 is required for 40S maturation in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:1043-1056. [PMID: 25319368 DOI: 10.1111/tpj.12703] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/01/2014] [Accepted: 10/06/2014] [Indexed: 06/04/2023]
Abstract
Ribosome biogenesis involves a large ensemble of trans-acting factors, which catalyse rRNA processing, ribosomal protein association and ribosomal subunit assembly. The circularly permuted GTPase Lsg1 is such a ribosome biogenesis factor, which is involved in maturation of the pre-60S ribosomal subunit in yeast. We identified two orthologues of Lsg1 in Arabidopsis thaliana. Both proteins differ in their C-terminus, which is highly charged in atLSG1-2 but missing in atLSG1-1. This C-terminus of atLSG1-2 contains a functional nuclear localization signal in a part of the protein that also targets atLSG1-2 to the nucleolus. Furthermore, only atLSG1-2 is physically associated with ribosomes suggesting its function in ribosome biogenesis. Homozygous T-DNA insertion lines are viable for both LSG1 orthologues. In plants lacking atLSG1-2 18S rRNA precursors accumulate and a 20S pre-rRNA is detected, while the amount of pre-rRNAs that lead to the 25S and 5.8S rRNA is not changed. Thus, our results suggest that pre-60S subunit maturation is important for the final steps of pre-40S maturation in plants. In addition, the lsg1-2 mutants show severe developmental defects, including triple cotyledons and upward curled leaves, which link ribosome biogenesis to early plant and leaf development.
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Affiliation(s)
- Benjamin L Weis
- Department of Biosciences, Goethe University, Molecular Cell Biology of Plants and Cluster of Excellence, Max von Laue Str. 9, 60438 Frankfurt/Main, Frankfurt, Germany
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Heo JB, Lee YM, Yun HR, Im CH, Lee YS, Yi YB, Kwon C, Lim J, Bahk JD. Rice serine/threonine kinase 1 is required for the stimulation of OsNug2 GTPase activity. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:1601-1608. [PMID: 25151129 DOI: 10.1016/j.jplph.2014.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/07/2014] [Accepted: 07/31/2014] [Indexed: 06/03/2023]
Abstract
Several GTPases are required for ribosome biogenesis and assembly. We recently identified rice (Oryza sativa) nuclear/nucleolar GTPase 2 (OsNug2), a YlqF/YawG family GTPase, as having a role in pre-60S ribosomal subunit maturation. To investigate the potential factors involved in regulating OsNug2 function, yeast two-hybrid screens were performed using OsNug2 as bait. Rice serine/threonine kinase 1 (OsSTK1) was identified as a candidate interacting protein. OsSTK1 appeared to interact with OsNug2 both in vitro and in vivo. OsSTK1 was found to have no effect on the GTP-binding activity of OsNug2; however, the presence of recombinant OsSTK1 in OsNug2 assay reaction mixtures increased OsNug2 GTPase activity. A kinase assay showed that OsSTK1 had weak autophosphorylation activity and strongly phosphorylated serine 209 of OsNug2. Using yeast complementation testing, we identified a GAL::OsNug2(S209N) mutation-harboring yeast strain that exhibited a growth-defective phenotype on galactose medium at 39°C, which was divergent from that of a yeast strain harboring GAL::OsNug2. The intrinsic GTPase activity of OsNug2(S209N), which was found to be similar to that of OsNug2, was not fully enhanced upon weak binding of OsSTK1. Our findings indicate that OsSTK1 functions as a positive regulator of OsNug2 by enhancing OsNug2 GTPase activity. In addition, phosphorylation of OsNug2 serine 209 is essential for its complete function in biological functional pathway.
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Affiliation(s)
- Jae Bok Heo
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, South Korea.
| | - Yun Mi Lee
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, South Korea
| | - Hee Rang Yun
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, South Korea
| | - Chak Han Im
- Eco-friendliness Research Department, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju 660-360, South Korea
| | - Yong-Suk Lee
- Department of Biotechnology, Dong-A University, Busan 604-714, South Korea
| | - Young Byong Yi
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, South Korea
| | - Chian Kwon
- Department of Molecular Biology, Dankook University, Yongin 448-701, South Korea
| | - Jun Lim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, South Korea
| | - Jeong Dong Bahk
- Department of Biochemistry, Gyeongsang National University, Jinju 660-701, South Korea
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Gulati M, Jain N, Davis JH, Williamson JR, Britton RA. Functional interaction between ribosomal protein L6 and RbgA during ribosome assembly. PLoS Genet 2014; 10:e1004694. [PMID: 25330043 PMCID: PMC4199504 DOI: 10.1371/journal.pgen.1004694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 08/21/2014] [Indexed: 01/06/2023] Open
Abstract
RbgA is an essential GTPase that participates in the assembly of the large ribosomal subunit in Bacillus subtilis and its homologs are implicated in mitochondrial and eukaryotic large subunit assembly. How RbgA functions in this process is still poorly understood. To gain insight into the function of RbgA we isolated suppressor mutations that partially restored the growth of an RbgA mutation (RbgA-F6A) that caused a severe growth defect. Analysis of these suppressors identified mutations in rplF, encoding ribosomal protein L6. The suppressor strains all accumulated a novel ribosome intermediate that migrates at 44S in sucrose gradients. All of the mutations cluster in a region of L6 that is in close contact with helix 97 of the 23S rRNA. In vitro maturation assays indicate that the L6 substitutions allow the defective RbgA-F6A protein to function more effectively in ribosome maturation. Our results suggest that RbgA functions to properly position L6 on the ribosome, prior to the incorporation of L16 and other late assembly proteins. Ribosomes are complex macromolecular machines that carry out the essential function of protein synthesis in the cell. The assembly of ribosomal subunits is a multistep process that involves the accurate and timely assembly of 3 rRNA molecules and>50 ribosomal-proteins. In recent years many ribosome assembly factors have been identified in bacterial and eukaryotic cells; however, their precise functions in ribosome biogenesis are poorly understood. We have previously shown that the GTPase RbgA, a protein conserved from bacteria to humans, is essential for ribosome assembly in Bacillus subtilis. Here, we show that growth defect caused by a mutation in RbgA is partially suppressed by mutations in ribosomal protein L6. The suppressor strains accumulate novel ribosomal intermediates that appear to suppress the RbgA defect by weakening the interaction of L6 for the ribosome and facilitating RbgA dependent assembly. Our work provides evidence for a functional interaction between ribosome assembly factor RbgA and ribosomal protein L6 during assembly, a function that is likely important for mitochondrial, chloroplast, and eukaryotic ribosome assembly as well.
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Affiliation(s)
- Megha Gulati
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Nikhil Jain
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Joseph H. Davis
- Department of Integrative Structural and Computational Biology, Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - James R. Williamson
- Department of Integrative Structural and Computational Biology, Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Robert A. Britton
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail: .
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Shi Y, Liu X, Li R, Gao Y, Xu Z, Zhang B, Zhou Y. Retention of OsNMD3 in the cytoplasm disturbs protein synthesis efficiency and affects plant development in rice. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3055-69. [PMID: 24723395 PMCID: PMC4071826 DOI: 10.1093/jxb/eru150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The ribosome is the basic machinery for translation, and biogenesis of ribosomes involves many coordinated events. However, knowledge about ribosomal dynamics in higher plants is very limited. This study chose a highly conserved trans-factor, the 60S ribosomal subunit nuclear export adaptor NMD3, to characterize the mechanism of ribosome biogenesis in the monocot plant Oryza sativa (rice). O. sativa NMD3 (OsNMD3) shares all the common motifs and shuttles between the nucleus and cytoplasm via CRM1/XPO1. A dominant negative form of OsNMD3 with a truncated nuclear localization sequence (OsNMD3(ΔNLS)) was retained in the cytoplasm, consequently interfering with the release of OsNMD3 from pre-60S particles and disturbing the assembly of ribosome subunits. Analyses of the transactivation activity and cellulose biosynthesis level revealed low protein synthesis efficiency in the transgenic plants compared with the wild-type plants. Pharmaceutical treatments demonstrated structural alterations in ribosomes in the transgenic plants. Moreover, global expression profiles of the wild-type and transgenic plants were investigated using the Illumina RNA sequencing approach. These expression profiles suggested that overexpression of OsNMD3(ΔNLS) affected ribosome biogenesis and certain basic pathways, leading to pleiotropic abnormalities in plant growth. Taken together, these results strongly suggest that OsNMD3 is important for ribosome assembly and the maintenance of normal protein synthesis efficiency.
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Affiliation(s)
- Yanyun Shi
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiangling Liu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Rui Li
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yaping Gao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zuopeng Xu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Baocai Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yihua Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Jeon Y, Ahn CS, Jung HJ, Kang H, Park GT, Choi Y, Hwang J, Pai HS. DER containing two consecutive GTP-binding domains plays an essential role in chloroplast ribosomal RNA processing and ribosome biogenesis in higher plants. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:117-30. [PMID: 24272962 PMCID: PMC3883289 DOI: 10.1093/jxb/ert360] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This study investigated protein characteristics and physiological functions of DER (Double Era-like GTPase) of higher plants. Nicotiana benthamiana DER (NbDER) contained two tandemly repeated GTP-binding domains (GD) and a C-terminal domain (CTD) that was similar to the K-homology domain involved in RNA binding. Both GDs possessed GTPase activity and contributed to the maximum GTPase activity of NbDER. NbDER fused to green fluorescent protein was localized primarily to chloroplast nucleoids. Arabidopsis der null mutants exhibited an embryonic lethal phenotype, indicating an essential function of DER during plant embryogenesis. Virus-induced gene silencing of NbDER resulted in a leaf-yellowing phenotype caused by disrupted chloroplast biogenesis. NbDER was associated primarily with the chloroplast 50S ribosomal subunit in vivo, and both the CTD and the two GD contributed to the association. Recombinant proteins of NbDER and its CTD could bind to 23S and 16S ribosomal RNAs in vitro. Depletion of NbDER impaired processing of plastid-encoded ribosomal RNAs, resulting in accumulation of the precursor rRNAs in the chloroplasts. NbDER-deficient chloroplasts contained significantly reduced levels of mature 23S and 16S rRNAs and diverse mRNAs in the polysomal fractions, suggesting decreased translation in chloroplasts. These results suggest that DER is involved in chloroplast rRNA processing and ribosome biogenesis in higher plants.
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Affiliation(s)
- Young Jeon
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Chang Sook Ahn
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
| | - Hyun Ju Jung
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea
| | - Hunseung Kang
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea
| | - Guen Tae Park
- School of Biological Sciences, Seoul National University, Seoul 151-;747, Korea
| | - Yeonhee Choi
- School of Biological Sciences, Seoul National University, Seoul 151-;747, Korea
| | - Jihwan Hwang
- Department of Microbiology, Pusan National University, Busan 609-735, Korea
| | - Hyun-Sook Pai
- Department of Systems Biology, Yonsei University, Seoul 120-749, Korea
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Missbach S, Weis BL, Martin R, Simm S, Bohnsack MT, Schleiff E. 40S ribosome biogenesis co-factors are essential for gametophyte and embryo development. PLoS One 2013; 8:e54084. [PMID: 23382868 PMCID: PMC3559688 DOI: 10.1371/journal.pone.0054084] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/05/2012] [Indexed: 12/13/2022] Open
Abstract
Ribosome biogenesis is well described in Saccharomyces cerevisiae. In contrast only very little information is available on this pathway in plants. This study presents the characterization of five putative protein co-factors of ribosome biogenesis in Arabidopsis thaliana, namely Rrp5, Pwp2, Nob1, Enp1 and Noc4. The characterization of the proteins in respect to localization, enzymatic activity and association with pre-ribosomal complexes is shown. Additionally, analyses of T-DNA insertion mutants aimed to reveal an involvement of the plant co-factors in ribosome biogenesis. The investigated proteins localize mainly to the nucleolus or the nucleus, and atEnp1 and atNob1 co-migrate with 40S pre-ribosomal complexes. The analysis of T-DNA insertion lines revealed that all proteins are essential in Arabidopsis thaliana and mutant plants show alterations of rRNA intermediate abundance already in the heterozygous state. The most significant alteration was observed in the NOB1 T-DNA insertion line where the P-A3 fragment, a 23S-like rRNA precursor, accumulated. The transmission of the T-DNA through the male and female gametophyte was strongly inhibited indicating a high importance of ribosome co-factor genes in the haploid stages of plant development. Additionally impaired embryogenesis was observed in some mutant plant lines. All results support an involvement of the analyzed proteins in ribosome biogenesis but differences in rRNA processing, gametophyte and embryo development suggested an alternative regulation in plants.
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Affiliation(s)
- Sandra Missbach
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Benjamin L. Weis
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Roman Martin
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Stefan Simm
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Markus T. Bohnsack
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
- Cluster of Excellence Frankfurt; Goethe University, Frankfurt/Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
- Cluster of Excellence Frankfurt; Goethe University, Frankfurt/Main, Germany
- Center of Membrane Proteomics, Goethe University, Frankfurt/Main, Germany
- * E-mail:
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18
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Gulati M, Jain N, Anand B, Prakash B, Britton RA. Mutational analysis of the ribosome assembly GTPase RbgA provides insight into ribosome interaction and ribosome-stimulated GTPase activation. Nucleic Acids Res 2013; 41:3217-27. [PMID: 23325847 PMCID: PMC3597669 DOI: 10.1093/nar/gks1475] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Ribosome biogenesis GTPase A protein (RbgA) is an essential GTPase required for the biogenesis of the 50S subunit in Bacillus subtilis. Homologs of RbgA are widely distributed in bacteria and eukaryotes and are implicated in ribosome assembly in the mitochondria, chloroplast and cytoplasm. Cells depleted of RbgA accumulate an immature large subunit that is missing key ribosomal proteins. RbgA, unlike many members of the Ras superfamily of GTPases, lacks a defined catalytic residue for carrying out guanosine triphosphate (GTP) hydrolysis. To probe RbgA function in ribosome assembly, we used a combined bioinformatics, genetic and biochemical approach. We identified a RNA-binding domain within the C-terminus of RbgA that is structurally similar to AmiR–NasR Transcription Anti-termination Regulator (ANTAR) domains, which are known to bind structured RNA. Mutation of key residues in the ANTAR domain altered RbgA association with the ribosome. We identified a putative catalytic residue within a highly conserved region of RbgA, His9, which is contained within a similar PGH motif found in elongation factor Tu (EF-Tu) that is required for GTP hydrolysis on interaction with the ribosome. Finally, our results support a model in which the GTPase activity of RbgA directly participates in the maturation of the large subunit rather than solely promoting dissociation of RbgA from the 50S subunit.
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Affiliation(s)
- Megha Gulati
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48823, USA
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Ash MR, Maher MJ, Mitchell Guss J, Jormakka M. The cation-dependent G-proteins: in a class of their own. FEBS Lett 2012; 586:2218-24. [PMID: 22750478 DOI: 10.1016/j.febslet.2012.06.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 06/14/2012] [Accepted: 06/19/2012] [Indexed: 12/31/2022]
Abstract
G-proteins are some of the most important and abundant enzymes, yet their intrinsic nucleotide hydrolysis reaction is notoriously slow and must be accelerated in vivo. Recent experiments on dynamin and GTPases involved in ribosome assembly have demonstrated that their hydrolysis activities are stimulated by potassium ions. This article presents the hypothesis that cation-mediated activation of G-proteins is more common than currently realised, and that such GTPases represent a structurally and functionally unique class of G-proteins. Based on sequence analysis we provide a list of predicted cation-dependent GTPases, which encompasses almost all members of the TEES, Obg-HflX, YqeH-like and dynamin superfamilies. The results from this analysis effectively re-define the conditions under which many of these G-proteins should be studied in vitro.
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Affiliation(s)
- Miriam-Rose Ash
- School of Molecular Bioscience, The University of Sydney, Australia.
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