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Wang Y, Zhu X, Wang J, Shen C, Wang W. Identification of Mycoparasitism-Related Genes against the Phytopathogen Botrytis cinerea via Transcriptome Analysis of Trichoderma harzianum T4. J Fungi (Basel) 2023; 9:jof9030324. [PMID: 36983492 PMCID: PMC10055783 DOI: 10.3390/jof9030324] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/15/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
Trichoderma harzianum is a well-known biological control agent (BCA) that is effective against a variety of plant pathogens. In previous studies, we found that T. harzianum T4 could effectively control the gray mold in tomatoes caused by Botrytis cinerea. However, the research on its biocontrol mechanism is not comprehensive, particularly regarding the mechanism of mycoparasitism. In this study, in order to further investigate the mycoparasitism mechanism of T. harzianum T4, transcriptomic sequencing and real-time fluorescence quantitative PCR (RT-qPCR) were used to identify the differentially expressed genes (DEGs) of T. harzianum T4 at 12, 24, 48 and 72 h of growth in the cell wall of B. cinerea (BCCW) or a sucrose medium. A total of 2871 DEGs and 2148 novel genes were detected using transcriptome sequencing. Through GO and KEGG enrichment analysis, we identified genes associated with mycoparasitism at specific time periods, such as encoding kinases, signal transduction proteins, carbohydrate active enzymes, hydrolytic enzymes, transporters, antioxidant enzymes, secondary metabolite synthesis, resistance proteins, detoxification genes and genes associated with extended hyphal longevity. To validate the transcriptome data, RT-qCPR was performed on the transcriptome samples. The RT-qPCR results show that the expression trend of the genes was consistent with the RNA-Seq data. In order to validate the screened genes associated with mycoparasitism, we performed a dual-culture antagonism test on T. harzianum and B. cinerea. The results of the dual-culture RT-qPCR showed that 15 of the 24 genes were upregulated during and after contact between T. harzianum T4 and B. cinerea (the same as BCCW), which further confirmed that these genes were involved in the mycoparasitism of T. harzianum T4. In conclusion, the transcriptome data provided in this study will not only improve the annotation information of gene models in T. harzianum T4 genome, but also provide important transcriptome information regarding the process of mycoparasitism at specific time periods, which can help us to further understand the mechanism of mycoparasitism, thus providing a potential molecular target for T. harzianum T4 as a biological control agent.
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Affiliation(s)
- Yaping Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaochong Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jian Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Chao Shen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
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2
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Grimes KM, Prasad V, Huo J, Kuwabara Y, Vanhoutte D, Baldwin TA, Bowers SLK, Johansen AKZ, Sargent MA, Lin SCJ, Molkentin JD. Rpl3l gene deletion in mice reduces heart weight over time. Front Physiol 2023; 14:1054169. [PMID: 36733907 PMCID: PMC9886673 DOI: 10.3389/fphys.2023.1054169] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/06/2023] [Indexed: 01/18/2023] Open
Abstract
Introduction: The ribosomal protein L3-like (RPL3L) is a heart and skeletal muscle-specific ribosomal protein and paralogue of the more ubiquitously expressed RPL3 protein. Mutations in the human RPL3L gene are linked to childhood cardiomyopathy and age-related atrial fibrillation, yet the function of RPL3L in the mammalian heart remains unknown. Methods and Results: Here, we observed that mouse cardiac ventricles express RPL3 at birth, where it is gradually replaced by RPL3L in adulthood but re-expressed with induction of hypertrophy in adults. Rpl3l gene-deleted mice were generated to examine the role of this gene in the heart, although Rpl3l -/- mice showed no overt changes in cardiac structure or function at baseline or after pressure overload hypertrophy, likely because RPL3 expression was upregulated and maintained in adulthood. mRNA expression analysis and ribosome profiling failed to show differences between the hearts of Rpl3l null and wild type mice in adulthood. Moreover, ribosomes lacking RPL3L showed no differences in localization within cardiomyocytes compared to wild type controls, nor was there an alteration in cardiac tissue ultrastructure or mitochondrial function in adult Rpl3l -/- mice. Similarly, overexpression of either RPL3 or RPL3L with adeno-associated virus -9 in the hearts of mice did not cause discernable pathology. However, by 18 months of age Rpl3l -/- null mice had significantly smaller hearts compared to wild type littermates. Conclusion: Thus, deletion of Rpl3l forces maintenance of RPL3 expression within the heart that appears to fully compensate for the loss of RPL3L, although older Rpl3l -/- mice showed a mild but significant reduction in heart weight.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Jeffery D. Molkentin
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH, United States
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3
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Rodríguez-Galán O, García-Gómez JJ, Rosado IV, Wei W, Méndez-Godoy A, Pillet B, Alekseenko A, Steinmetz L, Pelechano V, Kressler D, de la Cruz J. A functional connection between translation elongation and protein folding at the ribosome exit tunnel in Saccharomyces cerevisiae. Nucleic Acids Res 2021; 49:206-220. [PMID: 33330942 PMCID: PMC7797049 DOI: 10.1093/nar/gkaa1200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/18/2020] [Accepted: 12/14/2020] [Indexed: 12/03/2022] Open
Abstract
Proteostasis needs to be tightly controlled to meet the cellular demand for correctly de novo folded proteins and to avoid protein aggregation. While a coupling between translation rate and co-translational folding, likely involving an interplay between the ribosome and its associated chaperones, clearly appears to exist, the underlying mechanisms and the contribution of ribosomal proteins remain to be explored. The ribosomal protein uL3 contains a long internal loop whose tip region is in close proximity to the ribosomal peptidyl transferase center. Intriguingly, the rpl3[W255C] allele, in which the residue making the closest contact to this catalytic site is mutated, affects diverse aspects of ribosome biogenesis and function. Here, we have uncovered, by performing a synthetic lethal screen with this allele, an unexpected link between translation and the folding of nascent proteins by the ribosome-associated Ssb-RAC chaperone system. Our results reveal that uL3 and Ssb-RAC cooperate to prevent 80S ribosomes from piling up within the 5' region of mRNAs early on during translation elongation. Together, our study provides compelling in vivo evidence for a functional connection between peptide bond formation at the peptidyl transferase center and chaperone-assisted de novo folding of nascent polypeptides at the solvent-side of the peptide exit tunnel.
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Affiliation(s)
- Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Juan J García-Gómez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Iván V Rosado
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Wu Wei
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- CAS Key Lab of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Alfonso Méndez-Godoy
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Alisa Alekseenko
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Lars M Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
- Department of Genetics, School of Medicine, Stanford, CA, USA
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
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4
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Yodsurang V, Tang Y, Takahashi Y, Tanikawa C, Kamatani Y, Takahashi A, Momozawa Y, Fuse N, Sugawara J, Shimizu A, Fukushima A, Hishida A, Furusyo N, Naito M, Wakai K, Yamaji T, Sawada N, Iwasaki M, Tsugane S, Hirata M, Murakami Y, Kubo M, Matsuda K. Genome-wide association study (GWAS) of ovarian cancer in Japanese predicted regulatory variants in 22q13.1. PLoS One 2018; 13:e0209096. [PMID: 30557369 PMCID: PMC6296504 DOI: 10.1371/journal.pone.0209096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/29/2018] [Indexed: 12/22/2022] Open
Abstract
Genome-wide association studies (GWAS) have identified greater than 30 variants associated with ovarian cancer, but most of these variants were investigated in European populations. Here, we integrated GWAS and subsequent functional analyses to identify the genetic variants with potential regulatory effects. We conducted GWAS for ovarian cancer using 681 Japanese cases and 17,492 controls and found that rs137672 on 22q13.1 exhibited a strong association with a P-value of 1.05 × 10−7 and an odds ratio of 0.573 with a 95% confidence interval of 0.466–0.703. In addition, three previously reported SNPs, i.e., rs10088218, rs9870207 and rs1400482, were validated in the Japanese population (P < 0.05) with the same risk allele as noted in previous studies. Functional studies including regulatory feature analysis and electrophoretic mobility shift assay (EMSA) revealed two regulatory SNPs in 22q13.1, rs2072872 and rs6509, that affect the binding affinity to some nuclear proteins in ovarian cancer cells. The plausible regulatory proteins whose motifs could be affected by the allele changes of these two SNPs were also proposed. Moreover, the protective G allele of rs6509 was associated with a decreased SYNGR1 expression level in normal ovarian tissues. Our findings elucidated the regulatory variants in 22q13.1 that are associated with ovarian cancer risk.
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Affiliation(s)
- Varalee Yodsurang
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Yaqi Tang
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
- Institute of Pharmaceutical and Biological Sciences, University Claude Bernard Lyon 1, Lyon, France
| | - Yukie Takahashi
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
- Department of Hematology, Teikyo University Chiba Medical Center, Chiba, Japan
| | - Chizu Tanikawa
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | | | | | | | - Nobuo Fuse
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Junichi Sugawara
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Atsushi Shimizu
- Iwate Tohoku Medical Megabank Organization, Iwate Medical University, Iwate, Japan
| | - Akimune Fukushima
- Iwate Tohoku Medical Megabank Organization, Iwate Medical University, Iwate, Japan
| | - Asahi Hishida
- Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Norihiro Furusyo
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Fukuoka, Japan
| | - Mariko Naito
- Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Oral Epidemiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kenji Wakai
- Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Taiki Yamaji
- Division of Epidemiology, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Norie Sawada
- Division of Epidemiology, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Motoki Iwasaki
- Division of Epidemiology, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Shoichiro Tsugane
- Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Makoto Hirata
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Yoshinori Murakami
- Division of Molecular Pathology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Michiaki Kubo
- RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
| | - Koichi Matsuda
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
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5
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Makarova TM, Bogdanov AA. The Ribosome as an Allosterically Regulated Molecular Machine. BIOCHEMISTRY (MOSCOW) 2018. [PMID: 29523059 DOI: 10.1134/s0006297917130016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ribosome as a complex molecular machine undergoes significant conformational rearrangements during the synthesis of polypeptide chains of proteins. In this review, information obtained using various experimental methods on the internal consistency of such rearrangements is discussed. It is demonstrated that allosteric regulation involves all the main stages of the operation of the ribosome and connects functional elements remote by tens and even hundreds of angstroms. Data obtained using Förster resonance energy transfer (FRET) show that translocation is controlled in general by internal mechanisms of the ribosome, and not by the position of the ligands. Chemical probing data revealed the relationship of such remote sites as the decoding, peptidyl transferase, and GTPase centers of the ribosome. Nevertheless, despite the large amount of experimental data accumulated to date, many details and mechanisms of these phenomena are still not understood. Analysis of these data demonstrates that the development of new approaches is necessary for deciphering the mechanisms of allosteric regulation of the operation of the ribosome.
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Affiliation(s)
- T M Makarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
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6
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Nikulin AD. Structural Aspects of Ribosomal RNA Recognition by Ribosomal Proteins. BIOCHEMISTRY (MOSCOW) 2018; 83:S111-S133. [DOI: 10.1134/s0006297918140109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Kumari I, Ahmed M, Akhter Y. Deciphering the protein translation inhibition and coping mechanism of trichothecene toxin in resistant fungi. Int J Biochem Cell Biol 2016; 78:370-376. [DOI: 10.1016/j.biocel.2016.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 07/29/2016] [Accepted: 08/02/2016] [Indexed: 01/16/2023]
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8
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Fernández-Pevida A, Martín-Villanueva S, Murat G, Lacombe T, Kressler D, de la Cruz J. The eukaryote-specific N-terminal extension of ribosomal protein S31 contributes to the assembly and function of 40S ribosomal subunits. Nucleic Acids Res 2016; 44:7777-91. [PMID: 27422873 PMCID: PMC5027506 DOI: 10.1093/nar/gkw641] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/07/2016] [Indexed: 11/12/2022] Open
Abstract
The archaea-/eukaryote-specific 40S-ribosomal-subunit protein S31 is expressed as an ubiquitin fusion protein in eukaryotes and consists of a conserved body and a eukaryote-specific N-terminal extension. In yeast, S31 is a practically essential protein, which is required for cytoplasmic 20S pre-rRNA maturation. Here, we have studied the role of the N-terminal extension of the yeast S31 protein. We show that deletion of this extension partially impairs cell growth and 40S subunit biogenesis and confers hypersensitivity to aminoglycoside antibiotics. Moreover, the extension harbours a nuclear localization signal that promotes active nuclear import of S31, which associates with pre-ribosomal particles in the nucleus. In the absence of the extension, truncated S31 inefficiently assembles into pre-40S particles and two subpopulations of mature small subunits, one lacking and another one containing truncated S31, can be identified. Plasmid-driven overexpression of truncated S31 partially suppresses the growth and ribosome biogenesis defects but, conversely, slightly enhances the hypersensitivity to aminoglycosides. Altogether, these results indicate that the N-terminal extension facilitates the assembly of S31 into pre-40S particles and contributes to the optimal translational activity of mature 40S subunits but has only a minor role in cytoplasmic cleavage of 20S pre-rRNA at site D.
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Affiliation(s)
- Antonio Fernández-Pevida
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Sara Martín-Villanueva
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Guillaume Murat
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Thierry Lacombe
- Department of Microbiology and Molecular Medicine, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n; E-41013 Seville, Spain Departamento de Genética, Universidad de Sevilla, Seville, Spain
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9
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Zheng M, Wang Y, Liu X, Sun J, Wang Y, Xu Y, Lv J, Long W, Zhu X, Guo X, Jiang L, Wang C, Wan J. The RICE MINUTE-LIKE1 (RML1) gene, encoding a ribosomal large subunit protein L3B, regulates leaf morphology and plant architecture in rice. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3457-69. [PMID: 27241493 PMCID: PMC4939763 DOI: 10.1093/jxb/erw167] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Mutations of ribosomal proteins (RPs) are known to cause developmental abnormalities in yeast, mammals, and dicotyledonous plants; however, their effects have not been studied in rice. Here, we identifiy a ribosomal biogenesis mutant, rice minute-like1 (rml1) that displays a minute phenotype as evidenced by retarded growth and defects in the vascular system. We determine that RML1 encodes a ribosome large subunit protein 3B (RPL3B) in rice by means of map-based cloning and genetic complementation. RPL3B is abundantly expressed in all the tissues, whereas RPL3A, another RPL3 gene family member, is expressed at low levels. Notably, the expression level of RPL3A in the rml1 mutant is similar to that in the wild-type, suggesting that RPL3A provides no functional compensation for RPL3B in rml1 plants. Ribosomal profiles show that mutation of RPL3B leads to a significant reduction in free 60S ribosomal subunits and polysomes, indicating a ribosomal insufficiency in the rml1 mutant. Our results demonstrate that the ribosomal protein gene RPL3B is required for maintaining normal leaf morphology and plant architecture in rice through its regulation of ribosome biogenesis.
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Affiliation(s)
- Ming Zheng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Xi Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Juan Sun
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Yunlong Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Yang Xu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Jia Lv
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Wuhua Long
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Xiaopin Zhu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Xiuping Guo
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Chunming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
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10
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Mailliot J, Garreau de Loubresse N, Yusupova G, Meskauskas A, Dinman JD, Yusupov M. Crystal Structures of the uL3 Mutant Ribosome: Illustration of the Importance of Ribosomal Proteins for Translation Efficiency. J Mol Biol 2016; 428:2195-202. [PMID: 26906928 PMCID: PMC5331904 DOI: 10.1016/j.jmb.2016.02.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/09/2016] [Accepted: 02/10/2016] [Indexed: 11/17/2022]
Abstract
The ribosome has been described as a ribozyme in which ribosomal RNA is responsible for peptidyl-transferase reaction catalysis. The W255C mutation of the universally conserved ribosomal protein uL3 has diverse effects on ribosome function (e.g., increased affinities for transfer RNAs, decreased rates of peptidyl-transfer), and cells harboring this mutation are resistant to peptidyl-transferase inhibitors (e.g., anisomycin). These observations beg the question of how a single amino acid mutation may have such wide ranging consequences. Here, we report the structure of the vacant yeast uL3 W255C mutant ribosome by X-ray crystallography, showing a disruption of the A-site side of the peptidyl-transferase center (PTC). An additional X-ray crystallographic structure of the anisomycin-containing mutant ribosome shows that high concentrations of this inhibitor restore a "WT-like" configuration to this region of the PTC, providing insight into the resistance mechanism of the mutant. Globally, our data demonstrate that ribosomal protein uL3 is structurally essential to ensure an optimal and catalytically efficient organization of the PTC, highlighting the importance of proteins in the RNA-centered ribosome.
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Affiliation(s)
- Justine Mailliot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, 1 rue Laurent Fries, 67404 Illkirch-Graffenstaden, France.
| | - Nicolas Garreau de Loubresse
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, 1 rue Laurent Fries, 67404 Illkirch-Graffenstaden, France.
| | - Gulnara Yusupova
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, 1 rue Laurent Fries, 67404 Illkirch-Graffenstaden, France.
| | - Arturas Meskauskas
- Department of Cell Biology & Molecular Genetics, College of Life Sciences, College Park, MD 20742, USA.
| | - Jonathan D Dinman
- Department of Cell Biology & Molecular Genetics, College of Life Sciences, College Park, MD 20742, USA.
| | - Marat Yusupov
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, 1 rue Laurent Fries, 67404 Illkirch-Graffenstaden, France.
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11
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Chaillou T, Zhang X, McCarthy JJ. Expression of Muscle-Specific Ribosomal Protein L3-Like Impairs Myotube Growth. J Cell Physiol 2016; 231:1894-902. [PMID: 26684695 DOI: 10.1002/jcp.25294] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/17/2015] [Indexed: 12/11/2022]
Abstract
The ribosome has historically been considered to have no cell-specific function but rather serve in a "housekeeping" capacity. This view is being challenged by evidence showing that heterogeneity in the protein composition of the ribosome can lead to the functional specialization of the ribosome. Expression profiling of different tissues revealed that ribosomal protein large 3-like (Rpl3l) is exclusively expressed in striated muscle. In response to a hypertrophic stimulus, Rpl3l expression in skeletal muscle was significantly decreased by 82% whereas expression of the ubiquitous paralog Rpl3 was significantly increased by ∼fivefold. Based on these findings, we developed the hypothesis that Rpl3l functions as a negative regulator of muscle growth. To test this hypothesis, we used the Tet-On system to express Rpl3l in myoblasts during myotube formation. In support of our hypothesis, RPL3L expression significantly impaired myotube growth as assessed by myotube diameter (-23%) and protein content (-14%). Further analysis showed that the basis of this impairment was caused by a significant decrease in myoblast fusion as the fusion index was significantly lower (-17%) with RPL3L expression. These findings are the first evidence to support the novel concept of ribosome specialization in skeletal muscle and its role in the regulation of skeletal muscle growth. J. Cell. Physiol. 231: 1894-1902, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Thomas Chaillou
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Xiping Zhang
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - John J McCarthy
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
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12
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Mutations in the bacterial ribosomal protein l3 and their association with antibiotic resistance. Antimicrob Agents Chemother 2015; 59:3518-28. [PMID: 25845869 DOI: 10.1128/aac.00179-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Different groups of antibiotics bind to the peptidyl transferase center (PTC) in the large subunit of the bacterial ribosome. Resistance to these groups of antibiotics has often been linked with mutations or methylations of the 23S rRNA. In recent years, there has been a rise in the number of studies where mutations have been found in the ribosomal protein L3 in bacterial strains resistant to PTC-targeting antibiotics but there is often no evidence that these mutations actually confer antibiotic resistance. In this study, a plasmid exchange system was used to replace plasmid-carried wild-type genes with mutated L3 genes in a chromosomal L3 deletion strain. In this way, the essential L3 gene is available for the bacteria while allowing replacement of the wild type with mutated L3 genes. This enables investigation of the effect of single mutations in Escherichia coli without a wild-type L3 background. Ten plasmid-carried mutated L3 genes were constructed, and their effect on growth and antibiotic susceptibility was investigated. Additionally, computational modeling of the impact of L3 mutations in E. coli was used to assess changes in 50S structure and antibiotic binding. All mutations are placed in the loops of L3 near the PTC. Growth data show that 9 of the 10 mutations were well accepted in E. coli, although some of them came with a fitness cost. Only one of the mutants exhibited reduced susceptibility to linezolid, while five exhibited reduced susceptibility to tiamulin.
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13
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García-Gómez JJ, Fernández-Pevida A, Lebaron S, Rosado IV, Tollervey D, Kressler D, de la Cruz J. Final pre-40S maturation depends on the functional integrity of the 60S subunit ribosomal protein L3. PLoS Genet 2014; 10:e1004205. [PMID: 24603549 PMCID: PMC3945201 DOI: 10.1371/journal.pgen.1004205] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 01/13/2014] [Indexed: 01/21/2023] Open
Abstract
Ribosomal protein L3 is an evolutionarily conserved protein that participates in the assembly of early pre-60S particles. We report that the rpl3[W255C] allele, which affects the affinity and function of translation elongation factors, impairs cytoplasmic maturation of 20S pre-rRNA. This was not seen for other mutations in or depletion of L3 or other 60S ribosomal proteins. Surprisingly, pre-40S particles containing 20S pre-rRNA form translation-competent 80S ribosomes, and translation inhibition partially suppresses 20S pre-rRNA accumulation. The GTP-dependent translation initiation factor Fun12 (yeast eIF5B) shows similar in vivo binding to ribosomal particles from wild-type and rpl3[W255C] cells. However, the GTPase activity of eIF5B failed to stimulate processing of 20S pre-rRNA when assayed with ribosomal particles purified from rpl3[W255C] cells. We conclude that L3 plays an important role in the function of eIF5B in stimulating 3′ end processing of 18S rRNA in the context of 80S ribosomes that have not yet engaged in translation. These findings indicate that the correct conformation of the GTPase activation region is assessed in a quality control step during maturation of cytoplasmic pre-ribosomal particles. Recent progress has provided us with detailed knowledge of the structure and function of eukaryotic ribosomes. However, our understanding of the intricate processes of pre-ribosome assembly and the transition to translation-competent ribosomal subunits remains incomplete. The early and intermediate steps of ribosome assembly occur successively in the nucleolus and nucleoplasm. The pre-ribosomal subunits are then exported to the cytoplasm where final maturation steps, notably including D site cleavage of the 20S pre-rRNA to mature 18S rRNA, confer subunit joining and translation competence. Recent evidence indicates that pre-40S subunits are subject to a quality control step involving the GTP-dependent translation initiation factor eIF5B/Fun12, in the context of 80S-like ribosomes. Here, we demonstrate the involvement of 60S subunits in promoting 20S pre-rRNA cleavage. In particular, we show that a specific point mutation in the 60S subunit ribosomal protein L3 (rpl3[W255C]) leads to the accumulation of pre-40S particles that contain the 20S pre-rRNA but are translation-competent. Notably, this mutation prevents the stimulation of the GTPase activity of eIF5B/Fun12, which is also required for site D cleavage. We conclude that L3 plays an important role in regulating the function of eIF5B/Fun12 during 3′ end processing of 18S rRNA at site D, in the context of 80S ribosomes that have not yet engaged in translation.
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MESH Headings
- Alleles
- Cytoplasm/genetics
- Cytoplasm/metabolism
- Eukaryotic Initiation Factors/genetics
- Mutation
- Proteasome Endopeptidase Complex/genetics
- Proteasome Endopeptidase Complex/metabolism
- Protein Binding
- RNA Precursors/genetics
- RNA, Ribosomal, 18S/genetics
- Ribosomal Protein L3
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Large, Eukaryotic/genetics
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Saccharomyces cerevisiae/genetics
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Affiliation(s)
- Juan J. García-Gómez
- Departamento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Antonio Fernández-Pevida
- Departamento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Simon Lebaron
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Iván V. Rosado
- Departamento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jesús de la Cruz
- Departamento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- * E-mail:
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14
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A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7. Appl Microbiol Biotechnol 2014; 98:4625-36. [PMID: 24573606 DOI: 10.1007/s00253-014-5574-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 01/23/2014] [Accepted: 01/25/2014] [Indexed: 10/25/2022]
Abstract
The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.
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15
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Fernández-Pevida A, Rodríguez-Galán O, Díaz-Quintana A, Kressler D, de la Cruz J. Yeast ribosomal protein L40 assembles late into precursor 60 S ribosomes and is required for their cytoplasmic maturation. J Biol Chem 2012; 287:38390-407. [PMID: 22995916 DOI: 10.1074/jbc.m112.400564] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Most ribosomal proteins play important roles in ribosome biogenesis and function. Here, we have examined the contribution of the essential ribosomal protein L40 in these processes in the yeast Saccharomyces cerevisiae. Deletion of either the RPL40A or RPL40B gene and in vivo depletion of L40 impair 60 S ribosomal subunit biogenesis. Polysome profile analyses reveal the accumulation of half-mers and a moderate reduction in free 60 S ribosomal subunits. Pulse-chase, Northern blotting, and primer extension analyses in the L40-depleted strain clearly indicate that L40 is not strictly required for the precursor rRNA (pre-rRNA) processing reactions but contributes to optimal 27 SB pre-rRNA maturation. Moreover, depletion of L40 hinders the nucleo-cytoplasmic export of pre-60 S ribosomal particles. Importantly, all these defects most likely appear as the direct consequence of impaired Nmd3 and Rlp24 release from cytoplasmic pre-60 S ribosomal subunits and their inefficient recycling back into the nucle(ol)us. In agreement, we show that hemagglutinin epitope-tagged L40A assembles in the cytoplasm into almost mature pre-60 S ribosomal particles. Finally, we have identified that the hemagglutinin epitope-tagged L40A confers resistance to sordarin, a translation inhibitor that impairs the function of eukaryotic elongation factor 2, whereas the rpl40a and rpl40b null mutants are hypersensitive to this antibiotic. We conclude that L40 is assembled at a very late stage into pre-60 S ribosomal subunits and that its incorporation into 60 S ribosomal subunits is a prerequisite for subunit joining and may ensure proper functioning of the translocation process.
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16
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Meskauskas A, Dinman JD. A molecular clamp ensures allosteric coordination of peptidyltransfer and ligand binding to the ribosomal A-site. Nucleic Acids Res 2010; 38:7800-13. [PMID: 20660012 PMCID: PMC2995063 DOI: 10.1093/nar/gkq641] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although the ribosome is mainly comprised of rRNA and many of its critical functions occur through RNA–RNA interactions, distinct domains of ribosomal proteins also participate in switching the ribosome between different conformational/functional states. Prior studies demonstrated that two extended domains of ribosomal protein L3 form an allosteric switch between the pre- and post-translocational states. Missing was an explanation for how the movements of these domains are communicated among the ribosome's functional centers. Here, a third domain of L3 called the basic thumb, that protrudes roughly perpendicular from the W-finger and is nestled in the center of a cagelike structure formed by elements from three separate domains of the large subunit rRNA is investigated. Mutagenesis of basically charged amino acids of the basic thumb to alanines followed by detailed analyses suggests that it acts as a molecular clamp, playing a role in allosterically communicating the ribosome's tRNA occupancy status to the elongation factor binding region and the peptidyltransferase center, facilitating coordination of their functions through the elongation cycle. The observation that these mutations affected translational fidelity, virus propagation and cell growth demonstrates how small structural changes at the atomic scale can propagate outward to broadly impact the biology of cell.
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Affiliation(s)
- Arturas Meskauskas
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
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17
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Stupina VA, Meskauskas A, McCormack JC, Yingling YG, Shapiro BA, Dinman JD, Simon AE. The 3' proximal translational enhancer of Turnip crinkle virus binds to 60S ribosomal subunits. RNA (NEW YORK, N.Y.) 2008; 14:2379-93. [PMID: 18824512 PMCID: PMC2578866 DOI: 10.1261/rna.1227808] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 08/20/2008] [Indexed: 05/19/2023]
Abstract
During cap-dependent translation of eukaryotic mRNAs, initiation factors interact with the 5' cap to attract ribosomes. When animal viruses translate in a cap-independent fashion, ribosomes assemble upstream of initiation codons at internal ribosome entry sites (IRES). In contrast, many plant viral genomes do not contain 5' ends with substantial IRES activity but instead have 3' translational enhancers that function by an unknown mechanism. A 393-nucleotide (nt) region that includes the entire 3' UTR of the Turnip crinkle virus (TCV) synergistically enhances translation of a reporter gene when associated with the TCV 5' UTR. The major enhancer activity was mapped to an internal region of approximately 140 nt that partially overlaps with a 100-nt structural domain previously predicted to adopt a form with some resemblance to a tRNA, according to a recent study by J.C. McCormack and colleagues. The T-shaped structure binds to 80S ribosomes and 60S ribosomal subunits, and binding is more efficient in the absence of surrounding sequences and in the presence of a pseudoknot that mimics the tRNA-acceptor stem. Untranslated TCV satellite RNA satC, which contains the TCV 3' end and 6-nt differences in the region corresponding to the T-shaped element, does not detectably bind to 80S ribosomes and is not predicted to form a comparable structure. Binding of the TCV T-shaped element by 80S ribosomes was unaffected by salt-washing, reduced in the presence of AcPhe-tRNA, which binds to the P-site, and enhanced binding of Phe-tRNA to the ribosome A site. Mutations that reduced translation in vivo had similar effects on ribosome binding in vitro. This strong correlation suggests that ribosome entry in the 3' UTR is a key function of the 3' translational enhancer of TCV and that the T-shaped element contains some tRNA-like properties.
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Affiliation(s)
- Vera A Stupina
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, Maryland 20742, USA
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18
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Meskauskas A, Dinman JD. Ribosomal protein L3 functions as a 'rocker switch' to aid in coordinating of large subunit-associated functions in eukaryotes and Archaea. Nucleic Acids Res 2008; 36:6175-86. [PMID: 18832371 PMCID: PMC2577335 DOI: 10.1093/nar/gkn642] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Although ribosomal RNAs (rRNAs) comprise the bulk of the ribosome and carry out its main functions, ribosomal proteins also appear to play important structural and functional roles. Many ribosomal proteins contain long, nonglobular domains that extend deep into the rRNA cores. In eukaryotes and Archaea, ribosomal protein L3 contains two such extended domains tethered to a common globular hub, thus providing an excellent model to address basic questions relating to ribosomal protein structure/function relationships. Previous work in our laboratory identified the central ‘W-finger’ extension of yeast L3 in helping to coordinate ribosomal functions. New studies on the ‘N-terminal’ extension in yeast suggest that it works with the W-finger to coordinate opening and closing of the corridor through which the 3′ end of aa-tRNA moves during the process of accommodation. Additionally, the effect of one of the L3 N-terminal extension mutants on the interaction between C75 of the aa-tRNA and G2921 (Escherichia coli G2553) of 25S rRNA provides the first evidence of the effect of a ribosomal protein on aa-tRNA positioning and peptidyltransfer, possibly through the induced fit model. A model is presented describing how all three domains of L3 may function together as a ‘rocker switch’ to coordinate the stepwise processes of translation elongation.
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Affiliation(s)
- Arturas Meskauskas
- Department of Cell Biology and Molecular Genetics, Microbiology Building Rm. 2135, University of Maryland, College Park, MD 20742, USA
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19
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Rosado IV, Kressler D, de la Cruz J. Functional analysis of Saccharomyces cerevisiae ribosomal protein Rpl3p in ribosome synthesis. Nucleic Acids Res 2007; 35:4203-13. [PMID: 17569673 PMCID: PMC1919493 DOI: 10.1093/nar/gkm388] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Ribosome synthesis in eukaryotes requires a multitude of trans-acting factors. These factors act at many steps as the pre-ribosomal particles travel from the nucleolus to the cytoplasm. In contrast to the well-studied trans-acting factors, little is known about the contribution of the ribosomal proteins to ribosome biogenesis. Herein, we have analysed the role of ribosomal protein Rpl3p in 60S ribosomal subunit biogenesis. In vivo depletion of Rpl3p results in a deficit in 60S ribosomal subunits and the appearance of half-mer polysomes. This phenotype is likely due to the instability of early and intermediate pre-ribosomal particles, as evidenced by the low steady-state levels of 27SA3, 27SBS and 7SL/S precursors. Furthermore, depletion of Rpl3p impairs the nucleocytoplasmic export of pre-60S ribosomal particles. Interestingly, flow cytometry analysis indicates that Rpl3p-depleted cells arrest in the G1 phase. Altogether, we suggest that upon depletion of Rpl3p, early assembly of 60S ribosomal subunits is aborted and subsequent steps during their maturation and export prevented.
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Affiliation(s)
- Iván V. Rosado
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain and Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Dieter Kressler
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain and Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Jesús de la Cruz
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain and Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
- *To whom correspondence should be addressed. +34 95 455 71 06+34 95 455 71 04
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20
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Meskauskas A, Dinman JD. Ribosomal protein L3: gatekeeper to the A site. Mol Cell 2007; 25:877-88. [PMID: 17386264 PMCID: PMC1858676 DOI: 10.1016/j.molcel.2007.02.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 01/22/2007] [Accepted: 02/14/2007] [Indexed: 11/20/2022]
Abstract
Ribosomal protein L3 (L3) is an essential and indispensable component for formation of the peptidyltransferase center. Atomic resolution ribosome structures reveal two extensions of L3 protruding deep into the core of the large subunit. The central extension of L3 in Saccharomyces cerevisiae was investigated using a combination of molecular genetic, biochemical, chemical probing, and molecular modeling methods. A reciprocal relationship between ribosomal affinity for eEF-1A stimulated binding of aa-tRNA and for eEF2 suggests that the central extension of L3 may function as an allosteric switch in coordinating binding of the elongation factors. Opening of the aa-tRNA accommodation corridor promoted resistance to the A site-specific translational inhibitor anisomycin, suggesting a competitive model for anisomycin resistance. These changes were also found to inhibit peptidyltransferase activity, stimulating programmed -1 ribosomal frameshifting and promoting virus propagation defects. These studies provide a basis for deeper insight into rational design of small molecule antiviral therapeutics.
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Affiliation(s)
- Arturas Meskauskas
- Department of Cell Biology and Molecular Genetics, University of Maryland, Microbiology Building, Room 2135, College Park, MD 20742, USA.
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21
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Caprara MG, Chatterjee P, Solem A, Brady-Passerini KL, Kaspar BJ. An allosteric-feedback mechanism for protein-assisted group I intron splicing. RNA (NEW YORK, N.Y.) 2007; 13:211-22. [PMID: 17164477 PMCID: PMC1781373 DOI: 10.1261/rna.307907] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The I-AniI maturase facilitates self-splicing of a mitochondrial group I intron in Aspergillus nidulans. Binding occurs in at least two steps: first, a specific but labile encounter complex rapidly forms and then this intermediate is slowly resolved into a native, catalytically active RNA/protein complex. Here we probe the structure of the RNA throughout the assembly pathway. Although inherently unstable, the intron core, when bound by I-AniI, undergoes rapid folding to a near-native state in the encounter complex. The next transition includes the slow destabilization and docking into the core of the peripheral stacked helix that contains the 5' splice site. Mutational analyses confirm that both transitions are important for native complex formation. We propose that protein-driven destabilization and docking of the peripheral stacked helix lead to subtle changes in the I-AniI binding site that facilitate native complex formation. These results support an allosteric-feedback mechanism of RNA-protein recognition in which proteins engaged in an intermediate complex can influence RNA structure far from their binding sites. The linkage of these changes to stable binding ensures that the protein and RNA do not get sequestered in nonfunctional complexes.
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Affiliation(s)
- Mark G Caprara
- Center for RNA Molecular Biology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106-4960, USA.
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22
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Muldoon-Jacobs KL, Dinman JD. Specific effects of ribosome-tethered molecular chaperones on programmed -1 ribosomal frameshifting. EUKARYOTIC CELL 2006; 5:762-70. [PMID: 16607023 PMCID: PMC1459665 DOI: 10.1128/ec.5.4.762-770.2006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ribosome-associated molecular chaperone complexes RAC (Ssz1p/Zuo1p) and Ssb1p/Ssb2p expose a link between protein folding and translation. Disruption of the conserved nascent peptide-associated complex results in cell growth and translation fidelity defects. To better understand the consequences of deletion of either RAC or Ssb1p/2p, experiments relating to cell growth and programmed ribosomal frameshifting (PRF) were assayed. Genetic analyses revealed that deletion of Ssb1p/Ssb2p or of Ssz1p/Zuo1p resulted in specific inhibition of -1 PRF and defects in Killer virus maintenance, while no effects were observed on +1 PRF. These factors may provide a new set of targets to exploit against viruses that use -1 PRF. Quantitative measurements of growth profiles of isogenic wild-type and mutant cells showed that translational inhibitors exacerbate underlying growth defects in these mutants. Previous studies have identified -1 PRF signals in yeast chromosomal genes and have demonstrated an inverse relationship between -1 PRF efficiency and mRNA stability. Analysis of published DNA microarray experiments reveals conditions under which Ssb1, Ssb2, Ssz1, and Zuo1 transcript levels are regulated independently of those of genes encoding ribosomal proteins. Thus, the findings presented here suggest that these trans-acting factors could be used by cells to posttranscriptionally regulate gene expression through -1 PRF.
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Affiliation(s)
- Kristi L Muldoon-Jacobs
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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23
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Mansouri S, Nourollahzadeh E, Hudak KA. Pokeweed antiviral protein depurinates the sarcin/ricin loop of the rRNA prior to binding of aminoacyl-tRNA to the ribosomal A-site. RNA (NEW YORK, N.Y.) 2006; 12:1683-92. [PMID: 16888324 PMCID: PMC1557698 DOI: 10.1261/rna.70306] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Ribosome-inactivating proteins, such as the pokeweed antiviral protein (PAP), inhibit translation by depurinating the conserved sarcin/ricin loop of the large ribosomal RNA. Depurinated ribosomes are unable to bind elongation factor 2, and, thus, the translocation step of the elongation cycle is inhibited. Though the consequences of depurination are well characterized, the ribosome conformation required for depurination to take place has not been described. In this report, we correlate biochemical and genetic data to conclude that pokeweed antiviral protein depurinates the sarcin/ricin loop when the A-site of the ribosomal peptidyl-transferase center is unoccupied. We show that prior incubation of ribosomes with puromycin, an analog of the 3'-terminus of aminoacyl-tRNA, inhibits both binding and depurination by PAP in a concentration-dependent manner. Expression of PAP in the yeast strain mak8-1 results in little depurination unless the cells are lysed, a process that would promote loss of aminoacyl-tRNA from the ribosome. The mak8-1 strain is known to exhibit a higher affinity for aminoacyl-tRNA compared with wild-type cells, and therefore, its ribosomes are more resistant to PAP in vivo. These data contribute to the mechanism of action of pokeweed antiviral protein; specifically, they have uncovered the ribosomal conformation required for depurination that leads to subsequent translation inhibition.
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Affiliation(s)
- Sheila Mansouri
- Department of Biology, York University, Toronto, Ontario, M3J 1P3, Canada
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24
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Meskauskas A, Petrov AN, Dinman JD. Identification of functionally important amino acids of ribosomal protein L3 by saturation mutagenesis. Mol Cell Biol 2006; 25:10863-74. [PMID: 16314511 PMCID: PMC1316954 DOI: 10.1128/mcb.25.24.10863-10874.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There is accumulating evidence that many ribosomal proteins are involved in shaping rRNA into their functionally correct conformations through RNA-protein interactions. Moreover, although rRNA seems to play the central role in all aspects of ribosome function, ribosomal proteins may be involved in facilitating communication between different functional regions in ribosome, as well as between the ribosome and cellular factors. In an effort to more fully understand how ribosomal proteins may influence ribosome function, we undertook large-scale mutational analysis of ribosomal protein L3, a core protein of the large subunit that has been implicated in numerous ribosome-associated functions in the past. A total of 98 different rpl3 alleles were genetically characterized with regard to their effects on killer virus maintenance, programmed -1 ribosomal frameshifting, resistance/hypersensitivity to the translational inhibitor anisomycin and, in specific cases, the ability to enhance translation of a reporter mRNA lacking the 5' (7)mGppp cap structure and 3' poly(A) tail. Biochemical studies reveal a correlation between an increased affinity for aminoacyl-tRNA and the extent of anisomycin resistance and a decreased peptidyltransferase activity and increased frameshifting efficiency. Immunoblot analyses reveal that the superkiller phenotype is not due to a defect in the ability of ribosomes to recruit the Ski-complex, suggesting that the defect lies in a reduced ability of mutant ribosomes to distinguish between cap(+)/poly(A)(+) and cap(-)/poly(A)(-) mRNAs. The results of these analyses are discussed with regard to how protein-rRNA interactions may affect ribosome function.
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Affiliation(s)
- Arturas Meskauskas
- Department of Cell Biology and Molecular Genetics, Microbiology Building Room 2135, University of Maryland, College Park, 20742, USA
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25
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Maeder C, Draper DE. A Small Protein Unique to Bacteria Organizes rRNA Tertiary Structure Over an Extensive Region of the 50S Ribosomal Subunit. J Mol Biol 2005; 354:436-46. [PMID: 16246363 DOI: 10.1016/j.jmb.2005.09.072] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 09/22/2005] [Accepted: 09/22/2005] [Indexed: 11/17/2022]
Abstract
A number of small, basic proteins penetrate into the structure of the large subunit of the ribosome. While these proteins presumably aid in the folding of the rRNA, the extent of their contribution to the stability or function of the ribosome is unknown. One of these small, basic proteins is L36, which is highly conserved in Bacteria, but is not present in Archaea or Eucarya. Comparison of ribosome crystal structures shows that the space occupied by L36 in a bacterial ribosome is empty in an archaeal ribosome. To ask what L36 contributes to ribosome stability and function, we have constructed an Escherichia coli strain lacking ribosomal protein L36; cell growth is slowed by 40-50% between 30 degrees C and 42 degrees C. Ribosomes from this deletion strain sediment normally and have a full complement of proteins, other than L36. Chemical protection experiments comparing rRNA from wild-type and L36-deficient ribosomes show the expected increase in reagent accessibility in the immediate vicinity of the L36 binding site, but suggest that a cooperative network of rRNA tertiary interactions has been disrupted along a path extending 60 A deep into the ribosome. These data argue that L36 plays a significant role in organizing 23 S rRNA structure. Perhaps the Archaea and Eucarya have compensated for their lack of L36 by maintaining more stable rRNA tertiary contacts or by adopting alternative protein-RNA interactions elsewhere in the ribosome.
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Affiliation(s)
- Corina Maeder
- Program in Molecular and Computational Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
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Kiparisov S, Petrov A, Meskauskas A, Sergiev PV, Dontsova OA, Dinman JD. Structural and functional analysis of 5S rRNA in Saccharomyces cerevisiae. Mol Genet Genomics 2005; 274:235-47. [PMID: 16047201 PMCID: PMC1276653 DOI: 10.1007/s00438-005-0020-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Accepted: 05/27/2005] [Indexed: 11/26/2022]
Abstract
5S rRNA extends from the central protuberance of the large ribosomal subunit, through the A-site finger, and down to the GTPase-associated center. Here, we present a structure-function analysis of seven 5S rRNA alleles which are sufficient for viability in the yeast Saccharomyces cerevisiae when expressed in the absence of wild-type 5S rRNAs, and extend this analysis using a large bank of mutant alleles that show semi-dominant phenotypes in the presence of wild-type 5S rRNA. This analysis supports the hypothesis that 5S rRNA serves to link together several different functional centers of the ribosome. Data are also presented which suggest that in eukaryotic genomes selection has favored the maintenance of multiple alleles of 5S rRNA, and that these may provide cells with a mechanism to post-transcriptionally regulate gene expression.
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Di R, Tumer NE. Expression of a truncated form of ribosomal protein L3 confers resistance to pokeweed antiviral protein and the Fusarium mycotoxin deoxynivalenol. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:762-70. [PMID: 16134888 DOI: 10.1094/mpmi-18-0762] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The contamination of important agricultural products such as wheat, barley, or maize with the trichothecene mycotoxin deoxynivalenol (DON) due to infection with Fusarium species is a worldwide problem. Trichothecenes inhibit protein synthesis by targeting ribosomal protein L3. Pokeweed antiviral protein (PAP), a ribosome-inactivating protein binds to L3 to depurinate the alpha-sarcin/loop of the large rRNA. Plants transformed with the wild-type PAP show lesions and express very low levels of PAP because PAP autoregulates its expression by destabilizing its own mRNA. We show here that transgenic tobacco plants expressing both the wild-type PAP and a truncated form of yeast L3 (L3delta) are phenotypically normal. PAP mRNA and protein levels are very high in these plants, indicating that L3delta suppresses the autoregulation of PAP mRNA expression. Ribosomes are not depurinated in the transgenic plants expressing PAP and L3delta, even though PAP is associated with ribosomes. The expression of the endogenous tobacco ribosomal protein L3 is up-regulated in these plants and they are resistant to the Fusarium mycotoxin DON. These results demonstrate that expression of an N-terminal fragment of yeast L3 leads to trans-dominant resistance to PAP and the trichothecene mycotoxin DON, providing evidence that both toxins target L3 by a common mechanism.
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Affiliation(s)
- Rong Di
- Biotechnology Center for Agriculture and the Environment, Cook College, Rutgers University, New Brunswick, New Jersey 08901-8520, USA
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