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Miyoshi T, Nomura T, Takeya K, Uchiumi T. The natural bicyclic hexapeptide RA-VII is a novel inhibitor of the eukaryotic translocase eEF2. Biochem Biophys Res Commun 2022; 615:88-93. [DOI: 10.1016/j.bbrc.2022.05.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/11/2022] [Indexed: 11/17/2022]
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2
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Méndez-Godoy A, García-Montalvo D, Martínez-Castilla LP, Sánchez-Puig N. Evolutionary and functional relationships in the ribosome biogenesis SBDS and EFL1 protein families. Mol Genet Genomics 2021; 296:1263-1278. [PMID: 34453201 DOI: 10.1007/s00438-021-01814-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/15/2021] [Indexed: 11/25/2022]
Abstract
Nascent ribosomal 60S subunits undergo the last maturation steps in the cytoplasm. The last one involves removing the anti-association factor eIF6 from the 60S ribosomal surface by the joint action of the Elongation Factor-like 1 (EFL1) GTPase and the SBDS protein. Herein, we studied the evolutionary relationship of the EFL1 and EF-2 protein families and the functional conservation within EFL1 orthologues. Phylogenetic analysis demonstrated that the EFL1 proteins are exclusive of eukaryotes and share an evolutionary origin with the EF-2 and EF-G protein families. EFL1 proteins originated by gene duplication from the EF-2 proteins and specialized in ribosome maturation while the latter retained their function in translation. Some organisms have more than one EFL1 protein resulting from alternative splicing, while others are encoded in different genes originated by gene duplication. However, the function of these alternative EFL1 proteins is still unknown. We performed GTPase activity and complementation assays to study the functional conservation of EFL1 homologs alone and together with their SBDS counterparts. None of the orthologues or cross-species combinations could replace the function of the corresponding yeast EFL1•SBDS binomial. The complementation of SBDS interspecies chimeras indicates that domain 2 is vital for its function together with EFL1 and the 60S subunit. The results suggest a functional species-specificity and possible co-evolution between EFL1, SBDS, and the 60S ribosomal subunit. These findings set the basis for further studies directed to understand the molecular evolution of these proteins and their impact on ribosome biogenesis and disease.
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Affiliation(s)
- Alfonso Méndez-Godoy
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México, 04510, México.,Unit of Biochemistry, Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland
| | - Daniel García-Montalvo
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México, 04510, México
| | - León P Martínez-Castilla
- Departamento de Ciencias Naturales, Unidad Cuajimalpa, Universidad Autónoma Metropolitana, Ciudad de México, México
| | - Nuria Sánchez-Puig
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México, 04510, México.
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3
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Direct visualization of translational GTPase factor pool formed around the archaeal ribosomal P-stalk by high-speed AFM. Proc Natl Acad Sci U S A 2020; 117:32386-32394. [PMID: 33288716 PMCID: PMC7768734 DOI: 10.1073/pnas.2018975117] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Translation of genetic information by the ribosome is a core biological process in all organisms. The ribosomal stalk is a multimeric ribosomal protein complex which plays an essential role in translation elongation. However, the working mechanism of the ribosomal stalk still remains unclear. In this study, we applied HS-AFM to investigate the working mechanism of the archaeal ribosomal P-stalk. HS-AFM movies demonstrate that the P-stalk collects two translational GTPase factors (trGTPases), aEF1A and aEF2, and increases their local concentration near the ribosome. These direct visual evidences show that the multiple arms of the ribosomal P-stalk catch the trGTPases for efficient protein synthesis in the crowded intracellular environment. In translation elongation, two translational guanosine triphosphatase (trGTPase) factors EF1A and EF2 alternately bind to the ribosome and promote polypeptide elongation. The ribosomal stalk is a multimeric ribosomal protein complex which plays an essential role in the recruitment of EF1A and EF2 to the ribosome and their GTP hydrolysis for efficient and accurate translation elongation. However, due to the flexible nature of the ribosomal stalk, its structural dynamics and mechanism of action remain unclear. Here, we applied high-speed atomic force microscopy (HS-AFM) to directly visualize the action of the archaeal ribosomal heptameric stalk complex, aP0•(aP1•aP1)3 (P-stalk). HS-AFM movies clearly demonstrated the wobbling motion of the P-stalk on the large ribosomal subunit where the stalk base adopted two conformational states, a predicted canonical state, and a newly identified flipped state. Moreover, we showed that up to seven molecules of archaeal EF1A (aEF1A) and archaeal EF2 (aEF2) assembled around the ribosomal P-stalk, corresponding to the copy number of the common C-terminal factor-binding site of the P-stalk. These results provide visual evidence for the factor-pooling mechanism by the P-stalk within the ribosome and reveal that the ribosomal P-stalk promotes translation elongation by increasing the local concentration of translational GTPase factors.
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4
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Leucine 232 and hydrophobic residues at the ribosomal P stalk binding site are critical for biological activity of ricin. Biosci Rep 2020; 39:BSR20192022. [PMID: 31548364 PMCID: PMC6822507 DOI: 10.1042/bsr20192022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 01/16/2023] Open
Abstract
Ricin interacts with the ribosomal P stalk to cleave a conserved adenine from the α-sarcin/ricin loop (SRL) of the rRNA. Ricin toxin A chain (RTA) uses Arg235 as the most critical arginine for binding to the P stalk through electrostatic interactions to facilitate depurination. Structural analysis showed that a P2 peptide binds to a hydrophobic pocket on RTA and the last two residues form hydrogen bonds with Arg235. The importance of hydrophobic residues relative to Arg235 in the interaction with the P stalk in vivo and on the toxicity of RTA is not known. Here, we mutated residues in the hydrophobic pocket to analyze their contribution to toxicity and depurination activity in yeast and in mammalian cells. We found that Leu232, Tyr183 and Phe240 contribute cumulatively to toxicity, with Leu232 being the most significant. A quadruple mutant, Y183A/L232A/R235A/F240A, which combined mutations in critical hydrophobic residues with R235A completely abolished the activity of RTA, indicating that Arg235 and hydrophobic residues are required for full biological activity. Y183A and F240A mutants had reduced activity on RNA, but higher activity on ribosomes compared with R235A in vitro, suggesting that they could partially regain activity upon interaction with ribosomes. These results expand the region of interaction between RTA and the P stalk critical for cellular activity to include the hydrophobic pocket and provide the first evidence that interaction of P stalk with the hydrophobic pocket promotes a conformational rearrangement of RTA to correctly position the active site residues for catalytic attack on the SRL.
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Ito N, Anam MB, Ahmad SAI, Ohta K. Transdifferentiation of human somatic cells by ribosome. Dev Growth Differ 2018; 60:241-247. [PMID: 29845598 DOI: 10.1111/dgd.12538] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 04/18/2018] [Accepted: 04/18/2018] [Indexed: 01/19/2023]
Abstract
Ribosomes are intracellular organelles ubiquitous in all organisms, which translate information from mRNAs to synthesize proteins. They are complex macromolecules composed of dozens of proteins and ribosomal RNAs. Other than translation, some ribosomal proteins also have side-jobs called "Moonlighting" function. The majority of these moonlighting functions influence cancer progression, early development and differentiation. Recently, we discovered that ribosome is involved in the regulation of cellular transdifferentiation of human dermal fibroblasts (HDFs). In vitro incorporation of ribosomes into HDFs arrests cell proliferation and induces the formation of cell clusters, that differentiate into three germ layer derived cells upon induction by differentiation mediums. The discovery of ribosome induced transdifferentiation, that is not based on genetic modification, find new possibilities for the treatment of cancer and congenital diseases, as well as to understand early development and cellular lineage differentiation.
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Affiliation(s)
- Naofumi Ito
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,International Research Core for Stem Cell-based Developmental Medicine, Kumamoto University, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Kumamoto, Japan
| | - Mohammad Badrul Anam
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,International Research Core for Stem Cell-based Developmental Medicine, Kumamoto University, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Kumamoto, Japan
| | - Shah Adil Ishtiyaq Ahmad
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,International Research Core for Stem Cell-based Developmental Medicine, Kumamoto University, Kumamoto, Japan.,Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, Bangladesh
| | - Kunimasa Ohta
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,International Research Core for Stem Cell-based Developmental Medicine, Kumamoto University, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Kumamoto, Japan.,Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
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6
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Human ribosomal P1-P2 heterodimer represents an optimal docking site for ricin A chain with a prominent role for P1 C-terminus. Sci Rep 2017; 7:5608. [PMID: 28717148 PMCID: PMC5514047 DOI: 10.1038/s41598-017-05675-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/15/2017] [Indexed: 12/26/2022] Open
Abstract
The eukaryotic P-stalk contains two P1-P2 protein dimers with a conserved C- terminal domain (CTD) critical for the interaction with external factors. To understand the role of the individual CTD of human P1/P2 proteins, we examined the interaction of reconstituted human P-protein complexes and C-terminally truncated forms with ricin A chain (RTA), which binds to the stalk to depurinate the sarcin/ricin loop (SRL). The interaction between P-protein complexes and RTA was examined by surface plasmon resonance, isothermal titration calorimetry, microscale thermophoresis and bio-layer interferometry. The P1-P2 heterodimer missing a CTD on P2 was able to bind RTA. In contrast, the P1-P2 heterodimer missing the CTD of P1 protein displayed almost no binding toward RTA. Very low interaction was detected between RTA and the non-truncated P2-P2 homodimer, suggesting that the structural architecture of the P1-P2 heterodimer is critical for binding RTA. The reconstituted pentameric human stalk complex had higher affinity for RTA than the P1-P2 dimer. Deletion of P1 CTD, but not P2 CTD reduced the affinity of the pentamer for RTA. These results highlight the importance of the heterodimeric organization of P1-P2 in the human stalk pentamer and functional non-equivalence of the individual P-protein CTDs in the interaction with RTA.
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Mitroshin IV, Garber MB, Gabdulkhakov AG. Investigation of Structure of the Ribosomal L12/P Stalk. BIOCHEMISTRY (MOSCOW) 2017; 81:1589-1601. [PMID: 28260486 DOI: 10.1134/s0006297916130022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review contains recent data on the structure of the functionally important ribosomal domain, L12/P stalk, of the large ribosomal subunit. It is the most mobile site of the ribosome; it has been found in ribosomes of all living cells, and it is involved in the interaction between ribosomes and translation factors. The difference between the structures of the ribosomal proteins forming this protuberance (despite their general resemblance) determines the specificity of interaction between eukaryotic and prokaryotic ribosomes and the respective protein factors of translation. In this review, works on the structures of ribosomal proteins forming the L12/P-stalk in bacteria, archaea, and eukaryotes and data on structural aspects of interactions between these proteins and rRNA are described in detail.
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Affiliation(s)
- I V Mitroshin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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8
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Shigeno Y, Uchiumi T, Nomura T. Involvement of ribosomal protein L6 in assembly of functional 50S ribosomal subunit in Escherichia coli cells. Biochem Biophys Res Commun 2016; 473:237-242. [PMID: 27003253 DOI: 10.1016/j.bbrc.2016.03.085] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 03/18/2016] [Indexed: 11/28/2022]
Abstract
Ribosomal protein L6, an essential component of the large (50S) subunit, primarily binds to helix 97 of 23S rRNA and locates near the sarcin/ricin loop of helix 95 that directly interacts with GTPase translation factors. Although L6 is believed to play important roles in factor-dependent ribosomal function, crucial biochemical evidence for this hypothesis has not been obtained. We constructed and characterized an Escherichia coli mutant bearing a chromosomal L6 gene (rplF) disruption and carrying a plasmid with an arabinose-inducible L6 gene. Although this ΔL6 mutant grew more slowly than its wild-type parent, it proliferated in the presence of arabinose. Interestingly, cell growth in the absence of arabinose was biphasic. Early growth lasted only a few generations (LI-phase) and was followed by a suspension of growth for several hours (S-phase). This suspension was followed by a second growth phase (LII-phase). Cells harvested at both LI- and S-phases contained ribosomes with reduced factor-dependent GTPase activity and accumulated 50S subunit precursors (45S particles). The 45S particles completely lacked L6. Complete 50S subunits containing L6 were observed in all growth phases regardless of the L6-depleted condition, implying that the ΔL6 mutant escaped death because of a leaky expression of L6 from the complementing plasmid. We conclude that L6 is essential for the assembly of functional 50S subunits at the late stage. We thus established conditions for the isolation of L6-depleted 50S subunits, which are essential to study the role of L6 in translation.
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Affiliation(s)
- Yuta Shigeno
- Division of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Toshio Uchiumi
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Takaomi Nomura
- Division of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
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Imai H, Miyoshi T, Murakami R, Ito K, Ishino Y, Uchiumi T. Functional role of the C-terminal tail of the archaeal ribosomal stalk in recruitment of two elongation factors to the sarcin/ricin loop of 23S rRNA. Genes Cells 2015; 20:613-24. [DOI: 10.1111/gtc.12256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/27/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Hirotatsu Imai
- Department of Biology; Faculty of Science; Niigata University; 8050 Ikarashi 2-no-cho Nishi-ku Niigata 950-2181 Japan
| | - Tomohiro Miyoshi
- Department of Biology; Faculty of Science; Niigata University; 8050 Ikarashi 2-no-cho Nishi-ku Niigata 950-2181 Japan
| | - Ryo Murakami
- Department of Biology; Faculty of Science; Niigata University; 8050 Ikarashi 2-no-cho Nishi-ku Niigata 950-2181 Japan
| | - Kosuke Ito
- Department of Biology; Faculty of Science; Niigata University; 8050 Ikarashi 2-no-cho Nishi-ku Niigata 950-2181 Japan
| | - Yoshizumi Ishino
- Department of Bioscience and Biotechnology; Kyushu University; 6-10-1 Hakozaki Higashi-ku Fukuoka 812-8581 Japan
| | - Toshio Uchiumi
- Department of Biology; Faculty of Science; Niigata University; 8050 Ikarashi 2-no-cho Nishi-ku Niigata 950-2181 Japan
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Structures of eukaryotic ribosomal stalk proteins and its complex with trichosanthin, and their implications in recruiting ribosome-inactivating proteins to the ribosomes. Toxins (Basel) 2015; 7:638-47. [PMID: 25723321 PMCID: PMC4379515 DOI: 10.3390/toxins7030638] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/30/2015] [Accepted: 02/15/2015] [Indexed: 11/17/2022] Open
Abstract
Ribosome-inactivating proteins (RIP) are RNA N-glycosidases that inactivate ribosomes by specifically depurinating a conserved adenine residue at the α-sarcin/ricin loop of 28S rRNA. Recent studies have pointed to the involvement of the C-terminal domain of the eukaryotic stalk proteins in facilitating the toxic action of RIPs. This review highlights how structural studies of eukaryotic stalk proteins provide insights into the recruitment of RIPs to the ribosomes. Since the C-terminal domain of eukaryotic stalk proteins is involved in specific recognition of elongation factors and some eukaryote-specific RIPs (e.g., trichosanthin and ricin), we postulate that these RIPs may have evolved to hijack the translation-factor-recruiting function of ribosomal stalk in reaching their target site of rRNA.
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11
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Wawiórka L, Krokowski D, Gordiyenko Y, Krowarsch D, Robinson CV, Adam I, Grankowski N, Tchórzewski M. In vivo formation of Plasmodium falciparum ribosomal stalk - a unique mode of assembly without stable heterodimeric intermediates. Biochim Biophys Acta Gen Subj 2014; 1850:150-8. [PMID: 25450178 DOI: 10.1016/j.bbagen.2014.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/19/2014] [Accepted: 10/15/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND The ribosomal stalk composed of P-proteins constitutes a structure on the large ribosomal particle responsible for recruitment of translation factors and stimulation of factor-dependent GTP hydrolysis during translation. The main components of the stalk are P-proteins, which form a pentamer. Despite the conserved basic function of the stalk, the P-proteins do not form a uniform entity, displaying heterogeneity in the primary structure across the eukaryotic lineage. The P-proteins from protozoan parasites are among the most evolutionarily divergent stalk proteins. METHODS We have assembled P-stalk complex of Plasmodium falciparum in vivo in bacterial system using tricistronic expression cassette and provided its characteristics by biochemical and biophysical methods. RESULTS All three individual P-proteins, namely uL10/P0, P1 and P2, are indispensable for acquisition of a stable structure of the P stalk complex and the pentameric uL10/P0-(P1-P2)₂form represents the most favorable architecture for parasite P-proteins. CONCLUSION The formation of P. falciparum P-stalk is driven by trilateral interaction between individual elements which represents unique mode of assembling, without stable P1-P2 heterodimeric intermediate. GENERAL SIGNIFICANCE On the basis of our mass-spectrometry analysis supported by the bacterial two-hybrid assay and biophysical analyses, a unique pathway of the parasite stalk assembling has been proposed. We suggest that the absence of P1/P2 heterodimer, and the formation of a stable pentamer in the presence of all three proteins, indicate a one-step formation to be the main pathway for the vital ribosomal stalk assembly, whereas the P2 homo-oligomer may represent an off-pathway product with physiologically important nonribosomal role.
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Affiliation(s)
- Leszek Wawiórka
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Dawid Krokowski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Yuliya Gordiyenko
- Department of Chemistry, University of Oxford, South Parks Rd, Oxford OX1 3QZ, UK
| | - Daniel Krowarsch
- Department of Protein Biotechnology, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, South Parks Rd, Oxford OX1 3QZ, UK
| | - Ishag Adam
- Department of Obstetrics & Gynecology, Faculty of Medicine, AlKaser Street, University of Khartoum, Khartoum, Sudan
| | - Nikodem Grankowski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
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Hu M, Li L, Chao J, Zhao Y, Zhang Z, Liang A. The acidic ribosomal protein P2 from Euplotes octocarinatus is phosphorylated at its N-terminal domain. Biochem Cell Biol 2014; 92:23-32. [PMID: 24471915 DOI: 10.1139/bcb-2013-0063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The eukaryotic acid ribosomal P0, P1, and P2 proteins share a conserved flexible C-terminal tail that is rich in acidic residues, which are involved in the interaction with elongation factor 2 during protein synthesis. Our previous work suggested that the acidic ribosomal P proteins from Euplotes octocarinatus have a special C-terminal domain. To further understand this characteristic feature, both P2 and elongation factor 2 from E. octocarinatus were overexpressed, for the first time, in Escherichia coli in this study. GST pull-down assay indicated that P2 protein from E. octocarinatus (EoP2) interacted specifically with the N-terminal domain of elongation factor 2 from E. octocarinatus (EoEF-2) in vitro. The interacting part of EoP2 is in the C-terminal domains, consistent with the observation in other organisms. Phosphorylation of the recombinant EoP2 was performed in vitro using multiple methods such as (31)P-NMR spectroscopy, native PAGE, and Phos-tag(TM) SDS-PAGE. Results showed that ribosomal protein EoP2 was phosphorylated by casein kinase II at serine 21 located at the N terminus. This phosphorylation site identified in EoP2 is quite different from that of P2 from other organisms, in which the phosphorylation site is located in the conserved C-terminal region.
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Affiliation(s)
- Miaoqing Hu
- a Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
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Mitroshin I, Gabdulkhakov A, Garber M. The base of the ribosomal P stalk from Methanococcus jannaschii: crystallization and preliminary X-ray studies. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1288-90. [PMID: 24192371 DOI: 10.1107/s1744309113026729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 09/28/2013] [Indexed: 02/01/2024]
Abstract
The lateral P stalk in archaeal/eukaryotic ribosomes and the L12 stalk in bacterial ribosomes play a pivotal role in specific binding to the ribosome and recruiting translational factors during protein biosynthesis. The P stalk consists of the ribosomal proteins L11, P0 and P1. The proteins P0 and P1 form the complex that binds 23S rRNA through the N-terminal domain of the P0 protein. Ribosomal protein L11 binds to the same region of 23S rRNA and together with the protein P0 forms the base of the stalk. The structure of the ribosomal protein L11 from archaea has been solved, but with several missing segments. Here, the preparation and crystallization of a ternary complex consisting of the ribosomal protein L11, the two-domain N-terminal fragment of the ribosomal protein P0 and a specific fragment of 23S rRNA from the archaeon Methanococcus jannaschii are reported. The crystals belonged to the monoclinic space group P2(1), with unit-cell parameters a = 72.4, b = 88.5, c = 95.2 Å, β = 102.2°. A complete diffraction data set has been collected to a resolution of 2.9 Å using an in-house rotating-anode X-ray generator.
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Affiliation(s)
- Ivan Mitroshin
- Institute of Protein Research, Russian Academy of Sciences, Institutskaya 4, Pushchino, Moscow Region 142290, Russian Federation
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14
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Lee KM, Yusa K, Chu LO, Yu CWH, Oono M, Miyoshi T, Ito K, Shaw PC, Wong KB, Uchiumi T. Solution structure of human P1•P2 heterodimer provides insights into the role of eukaryotic stalk in recruiting the ribosome-inactivating protein trichosanthin to the ribosome. Nucleic Acids Res 2013; 41:8776-87. [PMID: 23892290 PMCID: PMC3794596 DOI: 10.1093/nar/gkt636] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lateral ribosomal stalk is responsible for binding and recruiting translation factors during protein synthesis. The eukaryotic stalk consists of one P0 protein with two copies of P1•P2 heterodimers to form a P0(P1•P2)2 pentameric P-complex. Here, we have solved the structure of full-length P1•P2 by nuclear magnetic resonance spectroscopy. P1 and P2 dimerize via their helical N-terminal domains, whereas the C-terminal tails of P1•P2 are unstructured and can extend up to ∼125 Å away from the dimerization domains. 15N relaxation study reveals that the C-terminal tails are flexible, having a much faster internal mobility than the N-terminal domains. Replacement of prokaryotic L10(L7/L12)4/L11 by eukaryotic P0(P1•P2)2/eL12 rendered Escherichia coli ribosome, which is insensitive to trichosanthin (TCS), susceptible to depurination by TCS and the C-terminal tail was found to be responsible for this depurination. Truncation and insertion studies showed that depurination of hybrid ribosome is dependent on the length of the proline-alanine rich hinge region within the C-terminal tail. All together, we propose a model that recruitment of TCS to the sarcin-ricin loop required the flexible C-terminal tail, and the proline-alanine rich hinge region lengthens this C-terminal tail, allowing the tail to sweep around the ribosome to recruit TCS.
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Affiliation(s)
- Ka-Ming Lee
- School of Life Sciences, Centre for Protein Science and Crystallography, The Chinese University of Hong Kong, Shatin, Hong Kong, China and Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
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15
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Davydov II, Wohlgemuth I, Artamonova II, Urlaub H, Tonevitsky AG, Rodnina MV. Evolution of the protein stoichiometry in the L12 stalk of bacterial and organellar ribosomes. Nat Commun 2013; 4:1387. [DOI: 10.1038/ncomms2373] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 12/12/2012] [Indexed: 01/08/2023] Open
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16
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Cryo-EM structure of the mammalian eukaryotic release factor eRF1-eRF3-associated termination complex. Proc Natl Acad Sci U S A 2012; 109:18413-8. [PMID: 23091004 DOI: 10.1073/pnas.1216730109] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Eukaryotic translation termination results from the complex functional interplay between two eukaryotic release factors, eRF1 and eRF3, and the ribosome, in which GTP hydrolysis by eRF3 couples codon recognition with peptidyl-tRNA hydrolysis by eRF1. Here, using cryo-electron microscopy (cryo-EM) and flexible fitting, we determined the structure of eRF1-eRF3-guanosine 5'-[β,γ-imido]triphosphate (GMPPNP)-bound ribosomal pretermination complex (pre-TC), which corresponds to the initial, pre-GTP hydrolysis stage of factor attachment. Our results show that eukaryotic translation termination involves a network of interactions between the two release factors and the ribosome. Our structure provides mechanistic insight into the coordination between GTP hydrolysis by eRF3 and subsequent peptide release by eRF1.
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Das S, Sudarsan R, Sivakami S, Sharma S. Erythrocytic stage-dependent regulation of oligomerization of Plasmodium ribosomal protein P2. J Biol Chem 2012; 287:41499-513. [PMID: 23060439 DOI: 10.1074/jbc.m112.384388] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The eukaryotic 60 S-ribosomal stalk consists of P0, P1, and P2 proteins, which associate in a pentameric structure (P1(2)-P0-P2(2)). The Plasmodium falciparum protein P2 (PfP2) appears to play nonribosomal roles. It gets exported to the infected erythrocyte (IE) surface at 30 h post-merozoite invasion (PMI), concomitant with extensive oligomerization. Here we present certain biophysical properties of PfP2. Recombinant P2 (rPfP2) protein showed SDS-resistant oligomerization, which could be significantly abolished under reducing conditions. However, the protein continued to oligomerize even when both cysteine residues were mutated, and with up to 40 amino acids (aa) deleted from the C-terminal end. CD analysis of P2 showed largely α-helical and random coil domains. The SDS- and DTT-resistant oligomerization was studied further as it occurred in a development-specific manner in Plasmodium. In a synchronized erythrocytic culture of P. falciparum, the PfP2 protein was detected as part of the ribosomal complex (∼96 kDa) at 18 and 30 h PMI, and was SDS sensitive. However, at 30 h, large amounts of SDS-sensitive aggregates of >600 kDa were also seen. At 30 h PMI, each of the parasites, IE cytosol and IE ghost contained 60-80-kDa PfP2 complexes, which resolved to a single 65-kDa species on SDS-PAGE. Tetramethylrhodamine-labeled rPfP2 protein exhibited DTT- and SDS-resistant oligomerization when treated with P. falciparum parasite extracts only from 24 to 36 h PMI, and multiple proteins appeared to be required for this oligomerization. Understanding the regulation of oligomerization of PfP2 may help in the elucidation of the novel structure-function relationship in the export of PfP2 to the red cell surface.
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Affiliation(s)
- Sudipta Das
- Department of Biological Sciences, Tata Institute of Fundamental Research, 400005 Mumbai, India
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18
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Solution structure of the natively assembled yeast ribosomal stalk determined by small-angle X-ray scattering. Biochem J 2012; 444:205-9. [DOI: 10.1042/bj20120115] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ribosomal stalk of the 60S subunit has been shown to play a crucial role in all steps of protein synthesis, but its structure and exact molecular function remain an unanswered question. In the present study, we show the low-resolution models of the solution structure of the yeast ribosomal stalk, composed of five proteins, P0–(P1–P2)2. The model of the pentameric stalk complex determined by small-angle X-ray scattering reveals an elongated shape with a maximum length of 13 nm. The model displays three distinct lobes, which may correspond to the individual P1–P2 heterodimers anchored to the C-terminal domain of the P0 protein.
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Wilson DN, Doudna Cate JH. The structure and function of the eukaryotic ribosome. Cold Spring Harb Perspect Biol 2012; 4:4/5/a011536. [PMID: 22550233 DOI: 10.1101/cshperspect.a011536] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Structures of the bacterial ribosome have provided a framework for understanding universal mechanisms of protein synthesis. However, the eukaryotic ribosome is much larger than it is in bacteria, and its activity is fundamentally different in many key ways. Recent cryo-electron microscopy reconstructions and X-ray crystal structures of eukaryotic ribosomes and ribosomal subunits now provide an unprecedented opportunity to explore mechanisms of eukaryotic translation and its regulation in atomic detail. This review describes the X-ray crystal structures of the Tetrahymena thermophila 40S and 60S subunits and the Saccharomyces cerevisiae 80S ribosome, as well as cryo-electron microscopy reconstructions of translating yeast and plant 80S ribosomes. Mechanistic questions about translation in eukaryotes that will require additional structural insights to be resolved are also presented.
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Koc EC, Koc H. Regulation of mammalian mitochondrial translation by post-translational modifications. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:1055-66. [PMID: 22480953 DOI: 10.1016/j.bbagrm.2012.03.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/24/2012] [Accepted: 03/16/2012] [Indexed: 11/29/2022]
Abstract
Mitochondria are responsible for the production of over 90% of the energy in eukaryotes through oxidative phosphorylation performed by electron transfer and ATP synthase complexes. Mitochondrial translation machinery is responsible for the synthesis of 13 essential proteins of these complexes encoded by the mitochondrial genome. Emerging data suggest that acetyl-CoA, NAD(+), and ATP are involved in regulation of this machinery through post-translational modifications of its protein components. Recent high-throughput proteomics analyses and mapping studies have provided further evidence for phosphorylation and acetylation of ribosomal proteins and translation factors. Here, we will review our current knowledge related to these modifications and their possible role(s) in the regulation of mitochondrial protein synthesis using the homology between mitochondrial and bacterial translation machineries. However, we have yet to determine the effects of phosphorylation and acetylation of translation components in mammalian mitochondrial biogenesis. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
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Affiliation(s)
- Emine C Koc
- Department of Biochemistry and Microbiology, Marshall University School of Medicine, Huntington, WV 25755, USA.
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Mochizuki M, Kitamyo M, Miyoshi T, Ito K, Uchiumi T. Analysis of chimeric ribosomal stalk complexes from eukaryotic and bacterial sources: structural features responsible for specificity of translation factors. Genes Cells 2012; 17:273-84. [DOI: 10.1111/j.1365-2443.2012.01586.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Abstract
Ricin and Shiga toxins designated as ribosome inactivating proteins (RIPs) are RNA N-glycosidases that depurinate a specific adenine (A₄₃₂₄ in rat 28S rRNA) in the conserved α-sarcin/ricin loop of the large rRNA, inhibiting protein synthesis. Evidence obtained from a number of studies suggests that interaction with ribosomal proteins plays an important role in the catalytic activity and ribosome specificity of RIPs. This review summarizes the recent developments in identification of the ribosomal proteins that interact with ricin and Shiga toxins and the principles governing these interactions.
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Affiliation(s)
- Nilgun E Tumer
- Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901-8520, USA.
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Lee KM, Yu CWH, Chiu TYH, Sze KH, Shaw PC, Wong KB. Solution structure of the dimerization domain of the eukaryotic stalk P1/P2 complex reveals the structural organization of eukaryotic stalk complex. Nucleic Acids Res 2011; 40:3172-82. [PMID: 22135285 PMCID: PMC3326305 DOI: 10.1093/nar/gkr1143] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The lateral ribosomal stalk is responsible for the kingdom-specific binding of translation factors and activation of GTP hydrolysis during protein synthesis. The eukaryotic stalk is composed of three acidic ribosomal proteins P0, P1 and P2. P0 binds two copies of P1/P2 hetero-dimers to form a pentameric P-complex. The structure of the eukaryotic stalk is currently not known. To provide a better understanding on the structural organization of eukaryotic stalk, we have determined the solution structure of the N-terminal dimerization domain (NTD) of P1/P2 hetero-dimer. Helix-1, -2 and -4 from each of the NTD-P1 and NTD-P2 form the dimeric interface that buries 2200 A2 of solvent accessible surface area. In contrast to the symmetric P2 homo-dimer, P1/P2 hetero-dimer is asymmetric. Three conserved hydrophobic residues on the surface of NTD-P1 are replaced by charged residues in NTD-P2. Moreover, NTD-P1 has an extra turn in helix-1, which forms extensive intermolecular interactions with helix-1 and -4 of NTD-P2. Truncation of this extra turn of P1 abolished the formation of P1/P2 hetero-dimer. Systematic truncation studies suggest that P0 contains two spine-helices that each binds one copy of P1/P2 hetero-dimer. Modeling studies suggest that a large hydrophobic cavity, which can accommodate the loop between the spine-helices of P0, can be found on NTD-P1 but not on NTD-P2 when the helix-4 adopts an ‘open’ conformation. Based on the asymmetric properties of NTD-P1/NTD-P2, a structural model of the eukaryotic P-complex with P2/P1:P1/P2 topology is proposed.
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Affiliation(s)
- Ka-Ming Lee
- School of Life Sciences, Centre for Protein Science and Crystallography, The Chinese University of Hong Kong, Hong Kong, China
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Proteomics of early and late cold shock stress on thermophilic bacterium, Thermus sp. GH5. J Proteomics 2011; 74:2100-11. [DOI: 10.1016/j.jprot.2011.05.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 05/18/2011] [Accepted: 05/25/2011] [Indexed: 11/19/2022]
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25
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Lee KM, Yu CWH, Chan DSB, Chiu TYH, Zhu G, Sze KH, Shaw PC, Wong KB. Solution structure of the dimerization domain of ribosomal protein P2 provides insights for the structural organization of eukaryotic stalk. Nucleic Acids Res 2010; 38:5206-16. [PMID: 20385603 PMCID: PMC2926600 DOI: 10.1093/nar/gkq231] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The lateral stalk of ribosome is responsible for kingdom-specific binding of translation factors and activation of GTP hydrolysis that drives protein synthesis. In eukaryotes, the stalk is composed of acidic ribosomal proteins P0, P1 and P2 that constitute a pentameric P-complex in 1: 2: 2 ratio. We have determined the solution structure of the N-terminal dimerization domain of human P2 (NTD-P2), which provides insights into the structural organization of the eukaryotic stalk. Our structure revealed that eukaryotic stalk protein P2 forms a symmetric homodimer in solution, and is structurally distinct from the bacterial counterpart L12 homodimer. The two subunits of NTD-P2 form extensive hydrophobic interactions in the dimeric interface that buries 2400 Å2 of solvent accessible surface area. We have showed that P1 can dissociate P2 homodimer spontaneously to form a more stable P1/P2 1 : 1 heterodimer. By homology modelling, we identified three exposed polar residues on helix-3 of P2 are substituted by conserved hydrophobic residues in P1. Confirmed by mutagenesis, we showed that these residues on helix-3 of P1 are not involved in the dimerization of P1/P2, but instead play a vital role in anchoring P1/P2 heterodimer to P0. Based on our results, models of the eukaryotic stalk complex were proposed.
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Affiliation(s)
- Ka-Ming Lee
- Department of Biochemistry, Centre for Protein Science and Crystallography, The Chinese University of Hong Kong, Hong Kong, China
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Miller JL, Cimen H, Koc H, Koc EC. Phosphorylated proteins of the mammalian mitochondrial ribosome: implications in protein synthesis. J Proteome Res 2010; 8:4789-98. [PMID: 19702336 DOI: 10.1021/pr9004844] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mitochondria, the powerhouse of eukaryotic cells, have their own translation machinery that is solely responsible for synthesis of 13 mitochondrially encoded protein subunits of oxidative phosphorylation complexes. Phosphorylation is a well-known post-translational modification in regulation of many processes in mammalian mitochondria including oxidative phosphorylation. However, there is still very limited knowledge on phosphorylation of mitochondrial ribosomal proteins and their role(s) in ribosome function. In this study, we have identified the mitochondrial ribosomal proteins that are phosphorylated at serine, threonine or tyrosine residues. Twenty-four phosphorylated proteins were visualized by phosphorylation-specific techniques including in vitro radiolabeling, residue specific antibodies for phosphorylated residues, or ProQ phospho dye and identified by tandem mass spectrometry. Translation assays with isolated ribosomes that were phosphorylated in vitro by kinases PKA, PKCdelta, or Abl Tyr showed up to 30% inhibition due to phosphorylation. Findings from this study should serve as the framework for future studies addressing the regulation mechanisms of mitochondrial translation machinery by phosphorylation and other post-translational modifications.
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Affiliation(s)
- Jennifer L Miller
- Department of Biochemistry & Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Grela P, Krokowski D, Gordiyenko Y, Krowarsch D, Robinson CV, Otlewski J, Grankowski N, Tchórzewski M. Biophysical Properties of the Eukaryotic Ribosomal Stalk. Biochemistry 2010; 49:924-33. [DOI: 10.1021/bi901811s] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Przemysław Grela
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Dawid Krokowski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Yuliya Gordiyenko
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB21EW, United Kingdom
| | - Daniel Krowarsch
- Laboratory of Protein Engineering, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
| | - Carol V. Robinson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB21EW, United Kingdom
| | - Jacek Otlewski
- Laboratory of Protein Engineering, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
| | - Nikodem Grankowski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
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Naganuma T, Nomura N, Yao M, Mochizuki M, Uchiumi T, Tanaka I. Structural basis for translation factor recruitment to the eukaryotic/archaeal ribosomes. J Biol Chem 2009; 285:4747-56. [PMID: 20007716 DOI: 10.1074/jbc.m109.068098] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The archaeal ribosomal stalk complex has been shown to have an apparently conserved functional structure with eukaryotic pentameric stalk complex; it provides access to eukaryotic elongation factors at levels comparable to that of the eukaryotic stalk. The crystal structure of the archaeal heptameric (P0(P1)(2)(P1)(2)(P1)(2)) stalk complex shows that the rRNA anchor protein P0 consists of an N-terminal rRNA-anchoring domain followed by three separated spine helices on which three P1 dimers bind. Based on the structure, we have generated P0 mutants depleted of any binding site(s) for P1 dimer(s). Factor-dependent GTPase assay of such mutants suggested that the first P1 dimer has higher activity than the others. Furthermore, we constructed a model of the archaeal 50 S with stalk complex by superposing the rRNA-anchoring domain of P0 on the archaeal 50 S. This model indicates that the C termini of P1 dimers where translation factors bind are all localized to the region between the stalk base of the 50 S and P0 spine helices. Together with the mutational experiments we infer that the functional significance of multiple copies of P1 is in creating a factor pool within a limited space near the stalk base of the ribosome.
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Affiliation(s)
- Takao Naganuma
- Faculty of Advanced Life Science, Hokkaido University, Kita-ku, Kita-10, Nishi-8, Sapporo, 060-0810, Japan
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Hellen CUT. IRES-induced conformational changes in the ribosome and the mechanism of translation initiation by internal ribosomal entry. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:558-70. [PMID: 19539793 DOI: 10.1016/j.bbagrm.2009.06.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/04/2009] [Accepted: 06/11/2009] [Indexed: 01/02/2023]
Abstract
Translation of the genomes of several positive-sense RNA viruses follows end-independent initiation on an internal ribosomal entry site (IRES) in the viral mRNA. There are four major IRES groups, and despite major differences in the mechanisms that they use, one unifying characteristic is that each mechanism involves essential non-canonical interactions of the IRES with components of the canonical translational apparatus. Thus the approximately 200nt.-long Type 4 IRESs (epitomized by Cricket paralysis virus) bind directly to the intersubunit space on the ribosomal 40S subunit, followed by joining to a 60S subunit to form active ribosomes by a factor-independent mechanism. The approximately 300nt.-long type 3 IRESs (epitomized by Hepatitis C virus) binds independently to eukaryotic initiation factor (eIF) 3, and to the solvent-accessible surface and E-site of the 40S subunit: addition of eIF2-GTP/initiator tRNA is sufficient to form a 48S complex that can join a 60S subunit in an eIF5/eIF5B-mediated reaction to form an active ribosome. Recent cryo-electron microscopy and biochemical analyses have revealed a second general characteristic of the mechanisms of initiation on Type 3 and Type 4 IRESs. Both classes of IRES induce similar conformational changes in the ribosome that influence entry, positioning and fixation of mRNA in the ribosomal decoding channel. HCV-like IRESs also stabilize binding of initiator tRNA in the peptidyl (P) site of the 40S subunit, whereas Type 4 IRESs induce changes in the ribosome that likely promote subsequent steps in the translation process, including subunit joining and elongation.
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Affiliation(s)
- Christopher U T Hellen
- Department of Cell Biology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 44, Brooklyn, NY 11203, USA.
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Miyoshi T, Nomura T, Uchiumi T. Engineering and characterization of the ribosomal L10.L12 stalk complex. A structural element responsible for high turnover of the elongation factor G-dependent GTPase. J Biol Chem 2008; 284:85-92. [PMID: 18936095 DOI: 10.1074/jbc.m806024200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ribosomal stalk protein L12 is essential for events dependent on the GTP-binding translation factors. It has been recently shown that ribosomes from Thermus thermophilus contain a heptameric complex L10.(L12)2.(L12)2.(L12)2, rather than the conventional pentameric complex L10.(L12)2.(L12)2. Here we describe the reconstitution of the heptameric complex from purified L10 and L12 and the characterization of its role in elongation factor G-dependent GTPase activity using a hybrid system with Escherichia coli ribosomes. The T. thermophilus heptameric complex resulted in a 2.5-fold higher activity than the E. coli pentameric complex. The structural element of the T. thermophilus complex responsible for the higher activity was investigated using a chimeric L10 protein (Ec-Tt-L10), in which the C-terminal L12-binding site in E. coli L10 was replaced with the same region from T. thermophilus, and two chimeric L12 proteins: Ec-Tt-L12, in which the E. coli N-terminal domain was fused with the T. thermophilus C-terminal domain, and Tt.Ec-L12, in which the T. thermophilus N-terminal domain was fused with the E. coli C-terminal domain. High GTPase turnover was observed with the pentameric chimeric complex formed from E. coli L10 and Ec-Tt-L12 but not with the heptameric complex formed from Ec-Tt-L10 and Tt.Ec-L12. This suggested that the C-terminal region of T. thermophilus L12, rather than the heptameric nature of the complex, was responsible for the high GTPase turnover. Further analyses with other chimeric L12 proteins identified helix alpha6 as the region most likely to contain the responsible element.
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Affiliation(s)
- Tomohiro Miyoshi
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan and the Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Takaomi Nomura
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan and the Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Toshio Uchiumi
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan and the Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
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Nomura T, Nakatsuchi M, Sugita D, Nomura M, Kaminishi T, Takemoto C, Shirouzu M, Miyoshi T, Yokoyama S, Hachimori A, Uchiumi T. Biochemical evidence for the heptameric complex L10(L12)6 in the Thermus thermophilus ribosome: in vitro analysis of its molecular assembly and functional properties. J Biochem 2008; 144:665-73. [PMID: 18784190 DOI: 10.1093/jb/mvn113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The stalk protein L12 is the only multiple component in 50S ribosomal subunit. In Escherichia coli, two L12 dimers bind to the C-terminal domain of L10 to form a pentameric complex, L10[(L12)(2)](2), while the recent X-ray crystallographic study and tandem MS analyses revealed the presence of a heptameric complex, L10[(L12)(2)](3), in some thermophilic bacteria. We here characterized the complex of Thermus thermophilus (Tt-) L10 and Tt-L12 stalk proteins by biochemical approaches using C-terminally truncated variants of Tt-L10. The C-terminal 44-residues removal (Delta44) resulted in complete loss of interactions with Tt-L12. Quantitative analysis of Tt-L12 assembled onto E. coli 50S core particles, together with Tt-L10 variants, indicated that the wild-type, Delta13 and Delta23 variants bound three, two and one Tt-L12 dimers, respectively. The hybrid ribosomes that contained the T. thermophilus proteins were highly accessible to E. coli elongation factors. The progressive removal of Tt-L12 dimers caused a stepwise reduction of ribosomal activities, which suggested that each individual stalk dimer contributed to ribosomal function. Interestingly, the hybrid ribosomes showed higher EF-G-dependent GTPase activity than E. coli ribosomes, even when two or one Tt-L12 dimer. This result seems to be due to a structural characteristic of Tt-L12 dimer.
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Affiliation(s)
- Takaomi Nomura
- Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567, Japan
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Jékely G. Origin of the nucleus and Ran-dependent transport to safeguard ribosome biogenesis in a chimeric cell. Biol Direct 2008; 3:31. [PMID: 18652645 PMCID: PMC2503971 DOI: 10.1186/1745-6150-3-31] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 07/24/2008] [Indexed: 11/18/2022] Open
Abstract
Background The origin of the nucleus is a central problem about the origin of eukaryotes. The common ancestry of nuclear pore complexes (NPC) and vesicle coating complexes indicates that the nucleus evolved via the modification of a pre-existing endomembrane system. Such an autogenous scenario is cell biologically feasible, but it is not clear what were the selective or neutral mechanisms that had led to the origin of the nuclear compartment. Results A key selective force during the autogenous origin of the nucleus could have been the need to segregate ribosome factories from the cytoplasm where ribosomal proteins (RPs) of the protomitochondrium were synthesized. After its uptake by an anuclear cell the protomitochondrium transferred several of its RP genes to the host genome. Alphaproteobacterial RPs and archaebacterial-type host ribosomes were consequently synthesized in the same cytoplasm. This could have led to the formation of chimeric ribosomes. I propose that the nucleus evolved when the host cell compartmentalised its ribosome factories and the tightly linked genome to reduce ribosome chimerism. This was achieved in successive stages by first evolving karyopherin and RanGTP dependent chaperoning of RPs, followed by the evolution of a membrane network to serve as a diffusion barrier, and finally a hydrogel sieve to ensure selective permeability at nuclear pores. Computer simulations show that a gradual segregation of cytoplasm and nucleoplasm via these steps can progressively reduce ribosome chimerism. Conclusion Ribosome chimerism can provide a direct link between the selective forces for and the mechanisms of evolving nuclear transport and compartmentalisation. The detailed molecular scenario presented here provides a solution to the gradual evolution of nuclear compartmentalization from an anuclear stage. Reviewers This article was reviewed by Eugene V Koonin, Martijn Huynen, Anthony M. Poole and Patrick Forterre.
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Affiliation(s)
- Gáspár Jékely
- Max Planck Institute for Developmental Biology, Spemannstrasse 35. 72076 Tübingen, Germany.
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Grela P, Bernadó P, Svergun D, Kwiatowski J, Abramczyk D, Grankowski N, Tchórzewski M. Structural Relationships Among the Ribosomal Stalk Proteins from the Three Domains of Life. J Mol Evol 2008; 67:154-67. [DOI: 10.1007/s00239-008-9132-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 05/10/2008] [Accepted: 06/09/2008] [Indexed: 11/30/2022]
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Bartish G, Nygård O. Importance of individual amino acids in the Switch I region in eEF2 studied by functional complementation in S. cerevisiae. Biochimie 2008; 90:736-48. [DOI: 10.1016/j.biochi.2008.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 01/17/2008] [Indexed: 10/22/2022]
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Miyoshi T, Uchiumi T. Functional interaction between bases C1049 in domain II and G2751 in domain VI of 23S rRNA in Escherichia coli ribosomes. Nucleic Acids Res 2008; 36:1783-91. [PMID: 18252772 PMCID: PMC2330231 DOI: 10.1093/nar/gkm1171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The factor-binding center within the Escherichia coli ribosome is comprised of two discrete domains of 23S rRNA: the GTPase-associated region (GAR) in domain II and the sarcin-ricin loop in domain VI. These two regions appear to collaborate in the factor-dependent events that occur during protein synthesis. Current X-ray crystallography of the ribosome shows an interaction between C1049 in the GAR and G2751 in domain VI. We have confirmed this interaction by site-directed mutagenesis and chemical probing. Disruption of this base pair affected not only the chemical modification of some bases in domains II and VI and in helix H89 of domain V, but also ribosome function dependent on both EF-G and EF-Tu. Mutant ribosomes carrying the C1049 to G substitution, which show enhancement of chemical modification at G2751, were used to probe the interactions between the regions around 1049 and 2751. Binding of EF-G-GDP-fusidic acid, but not EF-G-GMP-PNP, to the ribosome protected G2751 from modification. The G2751 protection was also observed after tRNA binding to the ribosomal P and E sites. The results suggest that the interactions between the bases around 1049 and 2751 alter during different stages of the translation process.
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Affiliation(s)
- Tomohiro Miyoshi
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
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36
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Naganuma T, Shiogama K, Uchiumi T. The N-terminal regions of eukaryotic acidic phosphoproteins P1 and P2 are crucial for heterodimerization and assembly into the ribosomal GTPase-associated center. Genes Cells 2007; 12:501-10. [PMID: 17397397 DOI: 10.1111/j.1365-2443.2007.01067.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acidic phosphoproteins P1 and P2 form a heterodimer and play a crucial role in assembly of the GTPase-associated center in eukaryotic ribosomes and in ribosomal interaction with translation factors. We investigated the structural elements within P1 and P2 essential for their dimerization and for ribosomal function. Truncation of the N-terminal 10 amino acids in either P1 or P2 and swapping of the N-terminal 10 amino acid sequences between these two proteins disrupted their dimerization, binding to P0 and P0 binding to rRNA. In contrast, truncation of the C-terminal halves of P1 and P2 as well as swapping of these parts between them gave no significant effects. The protein dimers containing the C-terminal truncation mutants or swapped variants were assembled with P0 onto Escherichia coli 50 S subunits deficient in the homologous protein L10 and L7/L12 and gave reduced ribosomal activity in terms of eukaryotic elongation factor dependent GTPase activity and polyphenylalanine synthesis. The results indicate that the N-terminal 10 amino acid sequences of both P1 and P2 are crucial for P1-P2 heterodimerization and for their functional assembly with P0 into the GTPase-associated center, whereas the C-terminal halves of P1 and P2 are not essential for the assembly.
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Affiliation(s)
- Takao Naganuma
- Department of Biology, Niigata University, Niigata 950-2181, Japan
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37
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Kavran JM, Steitz TA. Structure of the base of the L7/L12 stalk of the Haloarcula marismortui large ribosomal subunit: analysis of L11 movements. J Mol Biol 2007; 371:1047-59. [PMID: 17599351 DOI: 10.1016/j.jmb.2007.05.091] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/24/2007] [Accepted: 05/30/2007] [Indexed: 11/16/2022]
Abstract
Initiation factors, elongation factors, and release factors all interact with the L7/L12 stalk of the large ribosomal subunit during their respective GTP-dependent cycles on the ribosome. Electron density corresponding to the stalk is not present in previous crystal structures of either 50 S subunits or 70 S ribosomes. We have now discovered conditions that result in a more ordered factor-binding center in the Haloarcula marismortui (H.ma) large ribosomal subunit crystals and consequently allows the visualization of the full-length L11, the N-terminal domain (NTD) of L10 and helices 43 and 44 of 23 S rRNA. The resulting model is currently the most complete reported structure of a L7/L12 stalk in the context of a ribosome. This region contains a series of intermolecular interfaces that are smaller than those typically seen in other ribonucleoprotein interactions within the 50 S subunit. Comparisons of the L11 NTD position between the current structure, which is has an NTD splayed out with respect to previous structures, and other structures of ribosomes in different functional states demonstrates a dynamic range of L11 NTD movements. We propose that the L11 NTD moves through three different relative positions during the translational cycle: apo-ribosome, factor-bound pre-GTP hydrolysis and post-GTP hydrolysis. These positions outline a pathway for L11 NTD movements that are dependent on the specific nucleotide state of the bound ligand. These three states are represented by the orientations of the L11 NTD relative to the ribosome and suggest that L11 may play a more specialized role in the factor binding cycle than previously appreciated.
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Affiliation(s)
- Jennifer M Kavran
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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Chan DS, Chu LO, Lee KM, Too PH, Ma KW, Sze KH, Zhu G, Shaw PC, Wong KB. Interaction between trichosanthin, a ribosome-inactivating protein, and the ribosomal stalk protein P2 by chemical shift perturbation and mutagenesis analyses. Nucleic Acids Res 2007; 35:1660-72. [PMID: 17308345 PMCID: PMC1865052 DOI: 10.1093/nar/gkm065] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Trichosanthin (TCS) is a type I ribosome-inactivating protein that inactivates ribosome by enzymatically depurinating the A4324 at the α-sarcin/ricin loop of 28S rRNA. We have shown in this and previous studies that TCS interacts with human acidic ribosomal proteins P0, P1 and P2, which constitute the lateral stalk of eukaryotic ribosome. Deletion mutagenesis showed that TCS interacts with the C-terminal tail of P2, the sequences of which are conserved in P0, P1 and P2. The P2-binding site on TCS was mapped to the C-terminal domain by chemical shift perturbation experiments. Scanning charge-to-alanine mutagenesis has shown that K173, R174 and K177 in the C-terminal domain of TCS are involved in interacting with the P2, presumably through forming charge–charge interactions to the conserved DDD motif at the C-terminal tail of P2. A triple-alanine variant K173A/R174A/K177A of TCS, which fails to bind P2 and ribosomal stalk in vitro, was found to be 18-fold less active in inhibiting translation in rabbit reticulocyte lysate, suggesting that interaction with P-proteins is required for full activity of TCS. In an analogy to the role of stalk proteins in binding elongation factors, we propose that interaction with acidic ribosomal stalk proteins help TCS to locate its RNA substrate.
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Affiliation(s)
- Denise S.B. Chan
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Lai-On Chu
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Ka-Ming Lee
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Priscilla H.M. Too
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Kit-Wan Ma
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Kong-Hung Sze
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Guang Zhu
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Pang-Chui Shaw
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
| | - Kam-Bo Wong
- Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China, Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong, China and Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories, Hong Kong, China
- *To whom correspondence should be addressed. 852 2609 8024852 2603 7732 Correspondence may also be addressed to Pang-Chui Shaw. 852 2609 6803 852 2603 5123;
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39
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Krokowski D, Tchorzewski M, Boguszewska A, McKay AR, Maslen SL, Robinson CV, Grankowski N. Elevated copy number of L-A virus in yeast mutant strains defective in ribosomal stalk. Biochem Biophys Res Commun 2007; 355:575-80. [PMID: 17307145 DOI: 10.1016/j.bbrc.2007.02.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 02/02/2007] [Indexed: 11/21/2022]
Abstract
The eukaryotic ribosomal stalk, composed of the P-proteins, is a part of the GTPase-associated-center which is directly responsible for stimulation of translation-factor-dependent GTP hydrolysis. Here we report that yeast mutant strains lacking P1/P2-proteins show high propagation of the yeast L-A virus. Affinity-capture-MS analysis of a protein complex isolated from a yeast mutant strain lacking the P1A/P2B proteins using anti-P0 antibodies showed that the Gag protein, the major coat protein of the L-A capsid, is associated with the ribosomal stalk. Proteomic analysis revealed that the elongation factor eEF1A was also present in the isolated complex. Additionally, yeast strains lacking the P1/P2-proteins are hypersensitive to paromomycin and hygromycin B, underscoring the fact that structural perturbations in the stalk strongly influence the ribosome function, especially at the level of elongation.
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Affiliation(s)
- Dawid Krokowski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
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40
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Yamamoto H, Nakashima N, Ikeda Y, Uchiumi T. Binding mode of the first aminoacyl-tRNA in translation initiation mediated by Plautia stali intestine virus internal ribosome entry site. J Biol Chem 2007; 282:7770-6. [PMID: 17209036 DOI: 10.1074/jbc.m610887200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic ribosomes directly bind to the intergenic region-internal ribosome entry site (IGR-IRES) of Plautia stali intestine virus (PSIV) and initiate translation without either initiation factors or initiator Met-tRNA. We have investigated the mode of binding of the first aminoacyl-tRNA in translation initiation mediated by the IGR-IRES. Binding ability of aminoacyl-tRNA to the first codon within the IGR-IRES/80 S ribosome complex was very low in the presence of eukaryotic elongation factor 1A (eEF1A) alone but markedly enhanced by the translocase eEF2. Moreover, eEF2-dependent GTPase activity of the IRES/80 S ribosome complex was 3-fold higher than that of the free 80 S ribosome. This activation was suppressed by addition of the antibiotics pactamycin and hygromycin B, which are inhibitors of translocation. The results suggest that translocation by the action of eEF2 is essential for stable tRNA binding to the first codon of the PSIV-IRES in the ribosome. Chemical probing analysis showed that IRES binding causes a conformational change in helix 18 of 18 S rRNA at the A site such that IRES destabilizes the conserved pseudoknot within the helix. This conformational change caused by the PSIV-IRES may be responsible for the activation of eEF2 action and stimulation of the first tRNA binding to the P site without initiation factors.
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Affiliation(s)
- Hiroshi Yamamoto
- Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
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41
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Nomura T, Nakano K, Maki Y, Naganuma T, Nakashima T, Tanaka I, Kimura M, Hachimori A, Uchiumi T. In vitro reconstitution of the GTPase-associated centre of the archaebacterial ribosome: the functional features observed in a hybrid form with Escherichia coli 50S subunits. Biochem J 2006; 396:565-71. [PMID: 16594895 PMCID: PMC1482815 DOI: 10.1042/bj20060038] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We cloned the genes encoding the ribosomal proteins Ph (Pyrococcus horikoshii)-P0, Ph-L12 and Ph-L11, which constitute the GTPase-associated centre of the archaebacterium Pyrococcus horikoshii. These proteins are homologues of the eukaryotic P0, P1/P2 and eL12 proteins, and correspond to Escherichia coli L10, L7/L12 and L11 proteins respectively. The proteins and the truncation mutants of Ph-P0 were overexpressed in E. coli cells and used for in vitro assembly on to the conserved domain around position 1070 of 23S rRNA (E. coli numbering). Ph-L12 tightly associated as a homodimer and bound to the C-terminal half of Ph-P0. The Ph-P0.Ph-L12 complex and Ph-L11 bound to the 1070 rRNA fragments from the three biological kingdoms in the same manner as the equivalent proteins of eukaryotic and eubacterial ribosomes. The Ph-P0.Ph-L12 complex and Ph-L11 could replace L10.L7/L12 and L11 respectively, on the E. coli 50S subunit in vitro. The resultant hybrid ribosome was accessible for eukaryotic, as well as archaebacterial elongation factors, but not for prokaryotic elongation factors. The GTPase and polyphenylalanine-synthetic activity that is dependent on eukaryotic elongation factors was comparable with that of the hybrid ribosomes carrying the eukaryotic ribosomal proteins. The results suggest that the archaebacterial proteins, including the Ph-L12 homodimer, are functionally accessible to eukaryotic translation factors.
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Affiliation(s)
- Takaomi Nomura
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Kohji Nakano
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Yasushi Maki
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Takao Naganuma
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Takashi Nakashima
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Isao Tanaka
- ‡Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Makoto Kimura
- §Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Akira Hachimori
- *Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Toshio Uchiumi
- †Department of Biology, Faculty of Science, Niigata University, Niigata 950-2181, Japan
- To whom correspondence should be addressed (email )
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42
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Krokowski D, Boguszewska A, Abramczyk D, Liljas A, Tchórzewski M, Grankowski N. Yeast ribosomal P0 protein has two separate binding sites for P1/P2 proteins. Mol Microbiol 2006; 60:386-400. [PMID: 16573688 DOI: 10.1111/j.1365-2958.2006.05117.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The ribosome has a distinct lateral protuberance called the stalk; in eukaryotes it is formed by the acidic ribosomal P-proteins which are organized as a pentameric entity described as P0-(P1-P2)(2). Bilateral interactions between P0 and P1/P2 proteins have been studied extensively, however, the region on P0 responsible for the binding of P1/P2 proteins has not been precisely defined. Here we report a study which takes the current knowledge of the P0 - P1/P2 protein interaction beyond the recently published information. Using truncated forms of P0 protein and several in vitro and in vivo approaches, we have defined the region between positions 199 and 258 as the P0 protein fragment responsible for the binding of P1/P2 proteins in the yeast Saccharomyces cerevisiae. We show two short amino acid regions of P0 protein located at positions 199-230 and 231-258, to be responsible for independent binding of two dimers, P1A-P2B and P1B-P2A respectively. In addition, two elements, the sequence spanning amino acids 199-230 and the P1A-P2B dimer were found to be essential for stalk formation, indicating that this process is dependent on a balance between the P1A-P2B dimer and the P0 protein.
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Affiliation(s)
- Dawid Krokowski
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skodowska University, Akademicka 19, 20-033 Lublin, Poland
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Hagiya A, Naganuma T, Maki Y, Ohta J, Tohkairin Y, Shimizu T, Nomura T, Hachimori A, Uchiumi T. A Mode of Assembly of P0, P1, and P2 Proteins at the GTPase-associated Center in Animal Ribosome. J Biol Chem 2005; 280:39193-9. [PMID: 16188884 DOI: 10.1074/jbc.m506050200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosomal P0, P1, and P2 proteins, together with the conserved domain of 28 S rRNA, constitute a major part of the GTPase-associated center in eukaryotic ribosomes. We investigated the mode of assembly in vitro by using various truncation mutants of silkworm P0. When compared with wild type (WT)-P0, the C-terminal truncation mutants CDelta65 and CDelta81 showed markedly reduced binding ability to P1 and P2, which was offset by the addition of an rRNA fragment covering the P0.P1-P2 binding site. The mutant CDelta107 lost the P1/P2 binding activity, whereas it retained the rRNA binding. In contrast, the N-terminal truncation mutants NDelta21-NDelta92 completely lost the rRNA binding, although they retained P1/P2 binding capability, implying an essential role of the N terminus of P0 for rRNA binding. The P0 mutants NDelta6, NDelta14, and CDelta18-CDelta81, together with P1/P2 and eL12, bound to the Escherichia coli core 50 S subunits deficient in L10.L7/L12 complex and L11. Analysis of incorporation of (32)P-labeled P1/P2 into the 50 S subunits with WT-P0 and CDelta81 by sedimentation analysis indicated that WT-P0 bound two copies of P1 and P2, but CDelta81 bound only one copy each. The hybrid ribosome with CDelta81 that appears to contain one P1-P2 heterodimer retained lower but considerable activities dependent on eukaryotic elongation factors. These results suggested that two P1-P2 dimers bind to close but separate regions on the C-terminal half of P0. The results were further confirmed by binding experiments using chimeric P0 mutants in which the C-terminal 81 or 107 amino acids were replaced with the homologous sequences of the archaebacterial P0.
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Affiliation(s)
- Akiko Hagiya
- Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
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44
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Abo Y, Hagiya A, Naganuma T, Tohkairin Y, Shiomi K, Kajiura Z, Hachimori A, Uchiumi T, Nakagaki M. Baculovirus-mediated expression and isolation of human ribosomal phosphoprotein P0 carrying a GST-tag in a functional state. Biochem Biophys Res Commun 2004; 322:814-9. [PMID: 15336536 DOI: 10.1016/j.bbrc.2004.07.196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Indexed: 11/24/2022]
Abstract
We constructed an overexpression system for human ribosomal phosphoprotein P0, together with P1 and P2, which is crucially important for translation. Genes for these proteins, fused with the glutathione S-transferase (GST)-tag at the N-terminus, were inserted into baculovirus and introduced to insect cells. The fusion proteins, but not the proteins without the tag, were efficiently expressed into cells as soluble forms. The fusion protein GST.P0 as well as GST.P1/GST.P2 was phosphorylated in cells as detected by incorporation of (32)P and reactivity with monoclonal anti-phosphoserine antibody. GST.P0 expressed in insect cells, but not the protein obtained in Escherichia coli, had the ability to form a complex with P1 and P2 proteins and to bind to 28S rRNA. Moreover, the GST.P0-P1-P2 complex participated in high eEF-2-dependent GTPase activity. Baculovirus expression systems appear to provide recombinant human P0 samples that can be used for studies on the structure and function.
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Affiliation(s)
- Yohichi Abo
- Laboratory of Silkworm Genetics and Pathology, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
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45
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Terasaki M, Suzuki T, Hanada T, Watanabe K. Functional compatibility of elongation factors between mammalian mitochondrial and bacterial ribosomes: characterization of GTPase activity and translation elongation by hybrid ribosomes bearing heterologous L7/12 proteins. J Mol Biol 2004; 336:331-42. [PMID: 14757048 DOI: 10.1016/j.jmb.2003.12.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mammalian mitochondrial (mt) ribosome (mitoribosome) is a bacterial-type ribosome but has a highly protein-rich composition. Almost half of the rRNA contained in the bacterial ribosome is replaced with proteins in the mitoribosome. Escherichia coli elongation factor G (EF-G Ec) has no translocase activity on the mitoribosome but EF-G mt is functional on the E.coli ribosome. To investigate the functional equivalency of the mt and E.coli ribosomes, we prepared hybrid mt and E.coli ribosomes. The hybrid mitoribosome containing E.coli L7/12 (L7/12 Ec) instead of L7/12 mt clearly activated the GTPase of EF-G Ec and efficiently promoted its translocase activity in an in vitro translation system. Thus, the mitoribosome is functionally equivalent to the E.coli ribosome despite their distinct compositions. The mt EF-Tu-dependent translation activity of the E.coli ribosome was also clearly enhanced by replacing the C-terminal domain (CTD) of L7/12 Ec with the mt counterpart (the hybrid E.coli ribosome). This strongly indicates that the CTD of L7/12 is responsible for EF-Tu function. These results demonstrate that functional compatibility between elongation factors and the L7/12 protein in the ribosome governs its translational specificity.
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Affiliation(s)
- Maki Terasaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Bldg. FSB-301, 5-1-5 Kashiwanoha, Kashiwa, 277-8562, Chiba Prefecture, Japan
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Beckmann R, Spahn CM, Frank J, Blobel G. The active 80S ribosome-Sec61 complex. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 66:543-54. [PMID: 12762056 DOI: 10.1101/sqb.2001.66.543] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- R Beckmann
- Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York, New York 10021, USA
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47
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Polevoda B, Sherman F. N-terminal acetyltransferases and sequence requirements for N-terminal acetylation of eukaryotic proteins. J Mol Biol 2003; 325:595-622. [PMID: 12507466 DOI: 10.1016/s0022-2836(02)01269-x] [Citation(s) in RCA: 350] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
N(alpha)-terminal acetylation occurs in the yeast Saccharomyces cerevisiae by any of three N-terminal acetyltransferases (NAT), NatA, NatB, and NatC, which contain Ard1p, Nat3p and Mak3p catalytic subunits, respectively. The N-terminal sequences required for N-terminal acetylation, i.e. the NatA, NatB, and NatC substrates, were evaluated by considering over 450 yeast proteins previously examined in numerous studies, and were compared to the N-terminal sequences of more than 300 acetylated mammalian proteins. In addition, acetylated sequences of eukaryotic proteins were compared to the N termini of 810 eubacterial and 175 archaeal proteins, which are rarely acetylated. Protein orthologs of Ard1p, Nat3p and Mak3p were identified with the eukaryotic genomes of the sequences of model organisms, including Caenorhabditis elegans, Drosophila melanogaster, Arabidopsis thaliana, Mus musculus and Homo sapiens. Those and other putative acetyltransferases were assigned by phylogenetic analysis to the following six protein families: Ard1p; Nat3p; Mak3p; CAM; BAA; and Nat5p. The first three families correspond to the catalytic subunits of three major yeast NATs; these orthologous proteins were identified in eukaryotes, but not in prokaryotes; the CAM family include mammalian orthologs of the recently described Camello1 and Camello2 proteins whose substrates are unknown; the BAA family comprise bacterial and archaeal putative acetyltransferases whose biochemical activity have not been characterized; and the new Nat5p family assignment was on the basis of putative yeast NAT, Nat5p (YOR253W). Overall patterns of N-terminal acetylated proteins and the orthologous genes possibly encoding NATs suggest that yeast and higher eukaryotes have the same systems for N-terminal acetylation.
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Affiliation(s)
- Bogdan Polevoda
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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48
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Uchiumi T, Honma S, Endo Y, Hachimori A. Ribosomal proteins at the stalk region modulate functional rRNA structures in the GTPase center. J Biol Chem 2002; 277:41401-9. [PMID: 12198134 DOI: 10.1074/jbc.m207424200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Replacement of the L10.L7/L12 protein complex and L11 in Escherichia coli ribosomes with the respective rat counterparts P0.P1/P2 and eukaryotic L12 causes conversion of ribosomal specificity for elongation factors from prokaryotic elongation factor (EF)-Tu/EF-G to eukaryotic EF (eEF)-1alpha/eEF-2. Here we have investigated the effects of protein replacement on the structure and function of two rRNA domains around positions 1070 and 2660 (sarcin/ricin loop) of 23 S rRNA. Protein replacement at the 1070 region in E. coli 50 S subunits was demonstrated by chemical probing analysis. Binding of rat proteins to the 1070 region caused increased accessibility of the 2660 and 1070 regions to ligands for eukaryotic ribosomes: the ribotoxin pepocin for the 2660 region (E. coli numbering), anti-28 S autoantibody for the 1070 region, and eEF-2 for both regions. Moreover, binding of the E. coli L10.L7/L12 complex and L11 to the 1070 region was shown to be responsible for E. coli ribosomal accessibility to another ribotoxin, gypsophilin. Ribosomal proteins at the 1070 region appear to modulate the structures and functions of the 2660 and 1070 RNA regions in slightly different modes in prokaryotes and eukaryotes.
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Affiliation(s)
- Toshio Uchiumi
- Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
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Shimizu T, Nakagaki M, Nishi Y, Kobayashi Y, Hachimori A, Uchiumi T. Interaction among silkworm ribosomal proteins P1, P2 and P0 required for functional protein binding to the GTPase-associated domain of 28S rRNA. Nucleic Acids Res 2002; 30:2620-7. [PMID: 12060678 PMCID: PMC117291 DOI: 10.1093/nar/gkf379] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Acidic ribosomal phosphoproteins P0, P1 and P2 were isolated in soluble form from silkworm ribosomes and tested for their interactions with each other and with RNA fragments corresponding to the GTPase-associated domain of residues 1030-1127 (Escherichia coli numbering) in silkworm 28S rRNA in vitro. Mixing of P1 and P2 formed the P1-P2 heterodimer, as demonstrated by gel mobility shift and chemical crosslinking. This heterodimer, but neither P1 or P2 alone, tightly bound to P0 and formed a pentameric complex, presumably as P0(P1-P2)2, assumed from its molecular weight derived from sedimentation analysis. Complex formation strongly stimulated binding of P0 to the GTPase-associated RNA domain. The protein complex and eL12 (E.coli L11-type), which cross-bound to the E.coli equivalent RNA domain, were tested for their function by replacing with the E.coli counterparts L10.L7/L12 complex and L11 on the rRNA domain within the 50S subunits. Both P1 and P2, together with P0 and eL12, were required to activate ribosomes in polyphenylalanine synthesis dependent on eucaryotic elongation factors as well as eEF-2-dependent GTPase activity. The results suggest that formation of the P1-P2 heterodimer is required for subsequent formation of the P0(P1-P2)2 complex and its functional rRNA binding in silkworm ribosomes.
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Affiliation(s)
- Tomomi Shimizu
- Institute of High Polymer Research and Department of Applied Biological Science, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
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Uchiumi T, Honma S, Nomura T, Dabbs ER, Hachimori A. Translation elongation by a hybrid ribosome in which proteins at the GTPase center of the Escherichia coli ribosome are replaced with rat counterparts. J Biol Chem 2002; 277:3857-62. [PMID: 11729183 DOI: 10.1074/jbc.m107730200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosomal L10-L7/L12 protein complex and L11 bind to a highly conserved RNA region around position 1070 in domain II of 23 S rRNA and constitute a part of the GTPase-associated center in Escherichia coli ribosomes. We replaced these ribosomal proteins in vitro with the rat counterparts P0-P1/P2 complex and RL12, and tested them for ribosomal activities. The core 50 S subunit lacking the proteins on the 1070 RNA domain was prepared under gentle conditions from a mutant deficient in ribosomal protein L11. The rat proteins bound to the core 50 S subunit through their interactions with the 1070 RNA domain. The resultant hybrid ribosome was insensitive to thiostrepton and showed poly(U)-programmed polyphenylalanine synthesis dependent on the actions of both eukaryotic elongation factors 1alpha (eEF-1alpha) and 2 (eEF-2) but not of the prokaryotic equivalent factors EF-Tu and EF-G. The results from replacement of either the L10-L7/L12 complex or L11 with rat protein showed that the P0-P1/P2 complex, and not RL12, was responsible for the specificity of the eukaryotic ribosomes to eukaryotic elongation factors and for the accompanying GTPase activity. The presence of either E. coli L11 or rat RL12 considerably stimulated the polyphenylalanine synthesis by the hybrid ribosome, suggesting that L11/RL12 proteins play an important role in post-GTPase events of translation elongation.
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Affiliation(s)
- Toshio Uchiumi
- Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
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