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Bramasole L, Sinha A, Gurevich S, Radzinski M, Klein Y, Panat N, Gefen E, Rinaldi T, Jimenez-Morales D, Johnson J, Krogan NJ, Reis N, Reichmann D, Glickman MH, Pick E. Proteasome lid bridges mitochondrial stress with Cdc53/Cullin1 NEDDylation status. Redox Biol 2019; 20:533-543. [PMID: 30508698 PMCID: PMC6279957 DOI: 10.1016/j.redox.2018.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/11/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023] Open
Abstract
Cycles of Cdc53/Cullin1 rubylation (a.k.a NEDDylation) protect ubiquitin-E3 SCF (Skp1-Cullin1-F-box protein) complexes from self-destruction and play an important role in mediating the ubiquitination of key protein substrates involved in cell cycle progression, development, and survival. Cul1 rubylation is balanced by the COP9 signalosome (CSN), a multi-subunit derubylase that shows 1:1 paralogy to the 26S proteasome lid. The turnover of SCF substrates and their relevance to various diseases is well studied, yet, the extent by which environmental perturbations influence Cul1 rubylation/derubylation cycles per se is still unclear. In this study, we show that the level of cellular oxidation serves as a molecular switch, determining Cullin1 rubylation/derubylation ratio. We describe a mutant of the proteasome lid subunit, Rpn11 that exhibits accumulated levels of Cullin1-Rub1 conjugates, a characteristic phenotype of csn mutants. By dissecting between distinct phenotypes of rpn11 mutants, proteasome and mitochondria dysfunction, we were able to recognize the high reactive oxygen species (ROS) production during the transition of cells into mitochondrial respiration, as a checkpoint of Cullin1 rubylation in a reversible manner. Thus, the study adds the rubylation cascade to the list of cellular pathways regulated by redox homeostasis.
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Affiliation(s)
- L Bramasole
- Department of Human Biology, The Faculty of Natural Sciences, University of Haifa, Haifa 3190500, Israel; Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - A Sinha
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - S Gurevich
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - M Radzinski
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190400, Israel
| | - Y Klein
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - N Panat
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - E Gefen
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - T Rinaldi
- Department of Biology and Biotechnology, University of Rome ''La Sapienza'', Rome 00185, Italy
| | - D Jimenez-Morales
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - J Johnson
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - N J Krogan
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - N Reis
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - D Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190400, Israel
| | - M H Glickman
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - E Pick
- Department of Human Biology, The Faculty of Natural Sciences, University of Haifa, Haifa 3190500, Israel; Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel.
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2
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Taleb A, Kandilian R, Touchard R, Montalescot V, Rinaldi T, Taha S, Takache H, Marchal L, Legrand J, Pruvost J. Screening of freshwater and seawater microalgae strains in fully controlled photobioreactors for biodiesel production. Bioresour Technol 2016; 218:480-90. [PMID: 27394994 DOI: 10.1016/j.biortech.2016.06.086] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/21/2016] [Accepted: 06/22/2016] [Indexed: 05/18/2023]
Abstract
Strain selection is one of the primary hurdles facing cost-effective microalgal biodiesel production. Indeed, the strain used affects both upstream and downstream biodiesel production processes. This study presents a screening procedure that considers the most significant criteria in microalgal biodiesel production including TAG production and wet extraction and recovery of TAGs. Fourteen freshwater and seawater strains were investigated. Large variation was observed between the strains in all the screening criteria. The overall screening procedure ultimately led to the identification of Parachlorella kessleri UTEX2229 and Nannochloropsis gaditana CCMP527 as the best freshwater and seawater strains, respectively. They featured the largest areal TAG productivity equal to 2.7×10(-3) and 2.3×10(-3)kgm(-2)d(-1), respectively. These two strains also displayed encouraging cell fragility in a high pressure bead milling process with 69% and 98% cell disruption at 1750bar making them remarkable strains for TAG extraction in wet environment.
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Affiliation(s)
- A Taleb
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France; AZM Center for Biotechnology Research and Its Applications, Laboratory of Applied Biotechnology, Lebanese University, EDST, Tripoli, Lebanon; Department of Food Science and Technology, Faculty of Agricultural and Veterinary Medicine, Lebanese University, Dekweneh, Beirut, Lebanon
| | - R Kandilian
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - R Touchard
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - V Montalescot
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - T Rinaldi
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - S Taha
- AZM Center for Biotechnology Research and Its Applications, Laboratory of Applied Biotechnology, Lebanese University, EDST, Tripoli, Lebanon
| | - H Takache
- Department of Food Science and Technology, Faculty of Agricultural and Veterinary Medicine, Lebanese University, Dekweneh, Beirut, Lebanon
| | - L Marchal
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - J Legrand
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France
| | - J Pruvost
- GEPEA, Université de Nantes, CNRS UMR6144, bd de l'Université, CRTT, BP 406, 44602 Saint-Nazaire Cedex, France.
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Montalescot V, Rinaldi T, Touchard R, Jubeau S, Frappart M, Jaouen P, Bourseau P, Marchal L. Optimization of bead milling parameters for the cell disruption of microalgae: process modeling and application to Porphyridium cruentum and Nannochloropsis oculata. Bioresour Technol 2015; 196:339-346. [PMID: 26253918 DOI: 10.1016/j.biortech.2015.07.075] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/20/2015] [Accepted: 07/21/2015] [Indexed: 06/04/2023]
Abstract
A study of cell disruption by bead milling for two microalgae, Nannochloropsis oculata and Porphyridium cruentum, was performed. Strains robustness was quantified by high-pressure disruption assays. The hydrodynamics in the bead mill grinding chamber was studied by Residence Time Distribution modeling. Operating parameters effects were analyzed and modeled in terms of stress intensities and stress number. RTD corresponded to a 2 CSTR in series model. First order kinetics cell disruption was modeled in consequence. Continuous bead milling was efficient for both strains disruption. SI-SN modeling was successfully adapted to microalgae. As predicted by high pressure assays, N. oculata was more resistant than P. cruentum. The critical stress intensity was twice more important for N. oculata than for P. cruentum. SI-SN modeling allows the determination of operating parameters minimizing energy consumption and gives a scalable approach to develop and optimize microalgal disruption by bead milling.
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Affiliation(s)
- V Montalescot
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France
| | - T Rinaldi
- AlgoSource Technologies, 37 Bd de l'Université, 44600 Saint-Nazaire, France
| | - R Touchard
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France
| | - S Jubeau
- AlgoSource Technologies, 37 Bd de l'Université, 44600 Saint-Nazaire, France
| | - M Frappart
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France
| | - P Jaouen
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France
| | - P Bourseau
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France; UBS Université de Bretagne Sud, LIMATB, rue de Saint-Maudé, BP 92116, 56321 Lorient, France
| | - L Marchal
- Université de Nantes, CNRS, GEPEA, UMR-CNRS 6144, bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France
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Riccieri V, Rinaldi T, Spadaro A, Scrivo R, Ceccarelli F, Franco MD, Taccari E, Valesini G. Interleukin-13 in systemic sclerosis: relationship to nailfold capillaroscopy abnormalities. Clin Rheumatol 2003; 22:102-6. [PMID: 12740673 DOI: 10.1007/s10067-002-0684-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The aim of this study was to investigate whether interleukin-13 (IL-13) serum levels correlate to different nailfold capillaroscopy (NC) findings in patients with systemic sclerosis (SSc). IL-13 serum levels were measured using an ELISA method. The following NC abnormalities were considered: the presence of giant loops, haemorrhages, loss of capillaries, disorganisation of the vascular array, ramified/bushy capillaries and sludging of blood. A semiquantitative rating scale was adopted to score these changes, as well as a rating system for avascular areas and three morphological NC patterns ('early', 'active' and 'late'). Mean capillary density was determined by counting the total number of capillaries in a 1 mm length, and the arterial and venous diameters of the capillary as well as the total loop diameter were measured. In SSc patients IL-13 serum levels were significantly higher than in controls ( P < 00.1), whereas in patients with ( n=8) and without ( n=24) abnormal IL-13 serum levels (>17 pg/ml) the comparison of the NC features showed significantly relevant differences concerning a more frequent 'active' NC pattern ( P < 0.02), the presence of haemorrhages ( P < 0.0037) and sludging of blood ( P < 0.038), as well as larger total loop ( P < 0.036) and arterial ( P < 0.03) diameters, in those patients with elevated IL-13 serum levels. The study confirmed that IL-13 serum levels are higher in the sera of patients with SSc, and shows for the first time the significant correlations between this serological finding and some of the main relevant SSc capillaroscopic features, leading us to believe that this cytokine not only seems to sustain the immunological and fibrotic process of SSc, but might have a role in determining the more severe microvascular lesions in this disease.
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Affiliation(s)
- V Riccieri
- Dipartimento di Terapia Medica, Cattedra di Reumatologia, Università di Roma 'La Sapienza', 00185, Rome, Italy
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5
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Spadaro A, Scrivo R, Bombardieri M, Riccieri V, Rinaldi T, Taccari E, Valesini G. Relationship of interleukin-12 and interleukin-13 imbalance with class-specific rheumatoid factors and anticardiolipin antibodies in systemic lupus erythematosus. Clin Rheumatol 2003; 22:107-11. [PMID: 12740674 DOI: 10.1007/s10067-002-0685-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The aim of the study was to evaluate whether the imbalance between IL-12 and IL-13 serum levels, reflecting Th1/Th2 activity, is related to class-specific circulating rheumatoid factors (RF) and anticardiolipin (aCL) antibodies in SLE. Using ELISA we measured serum IL-12, IL-13, RF and aCL antibodies in 73 SLE patients and 20 healthy controls. The determination of IL-12/IL-13 ratio showed that IL-12 levels were above (group A), equal to (group B) or below (group C) IL-13 levels in 71.2%, 15.1% and 13.7% of SLE patients, respectively. IgM-RF levels were significantly higher in group C than in groups A ( P < 0.002) and B ( P < 0.019). Group C had also higher IgM-aCL levels than group A ( P < 0.04). No relationship between IL-12/IL-13 ratio and clinical or other laboratory parameters was found. It was concluded that the increased levels of both IgM-RF and IgM-aCL in patients with prevalent Th2 activity suggest that the predominance of Th2 over Th1 could drive autoantibody production in SLE patients.
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Affiliation(s)
- A Spadaro
- Dipartimento di Clinica e Terapia Medica Applicata, Università di Roma 'La Sapienza', Azienda Policlinico Umberto I, Viale del Policlinico 155, 00161 Rome, Italy
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Rinaldi T, Gambadoro A, Francisci S, Frontali L. Nucleo-mitochondrial interactions in Saccharomyces cerevisiae: characterization of a nuclear gene suppressing a defect in mitochondrial tRNA(Asp) processing. Gene 2003; 303:63-8. [PMID: 12559567 DOI: 10.1016/s0378-1119(02)01154-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We utilized the heat-sensitive mutant strain (Ts932), bearing a mutation at position 61 in the mitochondrial tRNA(Asp) gene, to identify nuclear genes involved in tRNA biogenesis; this mutant is defective in 3'-end processing and consequently in the production of mature mitochondrial tRNA(Asp). We transformed this strain with a yeast nuclear library and we isolated among other suppressors, an unknown, non-essential gene (called SMM1, corresponding to open reading frame YNR015w), which restored the growth on glycerol and a normal amount of processed tRNA(Asp) in the mutant. The gene contains a domain highly conserved in evolution from bacteria to human and its product has been recently shown to have dihydrouridine synthase activity.
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Affiliation(s)
- T Rinaldi
- Department of Cell and Developmental Biology, Pasteur Institute - Cenci Bolognetti Foundation, University of Rome I, Piazzale Aldo Moro 5, Italy.
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Feuermann M, Francisci S, Rinaldi T, De Luca C, Rohou H, Frontali L, Bolotin-Fukuhara M. The yeast counterparts of human 'MELAS' mutations cause mitochondrial dysfunction that can be rescued by overexpression of the mitochondrial translation factor EF-Tu. EMBO Rep 2003; 4:53-8. [PMID: 12524521 PMCID: PMC1315813 DOI: 10.1038/sj.embor.embor713] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2002] [Revised: 10/25/2002] [Accepted: 11/06/2002] [Indexed: 11/09/2022] Open
Abstract
We have taken advantage of the similarity between human and yeast (Saccharomyces cerevisiae) mitochondrial tRNA(Leu)(UUR), and of the possibility of transforming yeast mitochondria, to construct yeast mitochondrial mutations in the gene encoding tRNA(Leu)(UUR) equivalent to the human A3243G, C3256T and T3291C mutations that have been found in patients with the neurodegenerative disease MELAS (for mitochondrial 'myopathy, encephalopathy, lactic acidosis and stroke-like episodes'). The resulting yeast cells (bearing the equivalent mutations A14G, C26T and T69C) were defective for growth on respiratory substrates, exhibited an abnormal mitochondrial morphology, and accumulated mitochondrial DNA deletions at a very high rate, a trait characteristic of severe mitochondrial defects in protein synthesis. This effect was specific at least in the pathogenic mutation T69C, because when we introduced A or G instead of C, the respiratory defect was absent or very mild. All defective phenotypes returned to normal when the mutant cells were transformed by multicopy plasmids carrying the gene encoding the mitochondrial elongation factor EF-Tu. The ability to create and analyse such mutated strains and to select correcting genes should make yeast a good model for the study of tRNAs and their interacting partners and a practical tool for the study of pathological mutations and of tRNA sequence polymorphisms.
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MESH Headings
- Amino Acid Substitution
- Base Sequence
- Biolistics
- DNA, Mitochondrial/genetics
- Gene Expression Regulation, Fungal
- Genetic Vectors/genetics
- Humans
- MELAS Syndrome/genetics
- Mitochondria/physiology
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation, Missense
- Peptide Elongation Factor Tu/genetics
- Peptide Elongation Factor Tu/physiology
- Phenotype
- Point Mutation
- Protein Biosynthesis
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Transfer, Leu/chemistry
- RNA, Transfer, Leu/genetics
- Recombinant Fusion Proteins/physiology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/physiology
- Sequence Alignment
- Sequence Homology, Nucleic Acid
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Affiliation(s)
- M. Feuermann
- Laboratoire de Génétique Moléculaire, Institut de Génétique et Microbiologie, Bâtiment 400, Université Paris Sud, 91405 Orsay Cedex, France
- These authors contributed equally to the work
| | - S. Francisci
- Pasteur Institute—Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome I 'La Sapienza', Piazzale Aldo Moro 5, I-00185 Rome, Italy
- These authors contributed equally to the work
- Tel/Fax: +39 06 4461980;
| | - T. Rinaldi
- Pasteur Institute—Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome I 'La Sapienza', Piazzale Aldo Moro 5, I-00185 Rome, Italy
| | - C. De Luca
- Pasteur Institute—Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome I 'La Sapienza', Piazzale Aldo Moro 5, I-00185 Rome, Italy
| | - H. Rohou
- Laboratoire de Génétique Moléculaire, Institut de Génétique et Microbiologie, Bâtiment 400, Université Paris Sud, 91405 Orsay Cedex, France
| | - L. Frontali
- Pasteur Institute—Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome I 'La Sapienza', Piazzale Aldo Moro 5, I-00185 Rome, Italy
| | - M. Bolotin-Fukuhara
- Laboratoire de Génétique Moléculaire, Institut de Génétique et Microbiologie, Bâtiment 400, Université Paris Sud, 91405 Orsay Cedex, France
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Spadaro A, Scrivo R, Rinaldi T, Riccieri V, Sili Scavalli A, Taccari E, Valesini G. [The role of interleukin-12 in immune-mediated rheumatic diseases]. Reumatismo 2002; 54:113-21. [PMID: 12105679 DOI: 10.4081/reumatismo.2002.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE IL-12 is a proinflammatory cytokine produced by different antigen presenting cells. It has been shown to exert a critical role in inducing Th1 phenotype, thus initiating cell-mediated immune responses, but the significance of IL-12 in rheumatic diseases is not clear. Aim of the study was to determine IL-12 serum levels in immune rheumatic diseases and to analyse the relationship of this cytokine with main clinical and laboratory parameters. METHODS We analysed, by ELISA, serum IL-12 levels in 114 patients with SLE, 47 with SS, 32 with SSc, 84 with RA, 138 with PA and in 17 healthy controls. We also examined main clinical and laboratory parameters, including autoantibody profile and clinical indices of disease activity. RESULTS IL-12 serum levels were significantly higher in SLE and SS patients respect to controls. IL-12 serum levels were significantly higher in SLE patients compared to those affected by RA, PA and SSc. When we evaluated disease activity in SLE patients, we found significantly higher IL-12 serum levels in subjects with fever or in those without renal involvement, while no correlation was found in the other rheumatic immune diseases. CONCLUSIONS These findings suggest that IL-12, modulating cell and humoral immune responses, is involved in the pathogenesis of immune rheumatic diseases, such as SLE and SS.
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Affiliation(s)
- A Spadaro
- Dipartimento di Terapia Medica, Divisione di Reumatologia, Università di Roma La Sapienza, Italia.
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Rinaldi T, Ricordy R, Bolotin-Fukuhara M, Frontali L. Mitochondrial effects of the pleiotropic proteasomal mutation mpr1/rpn11: uncoupling from cell cycle defects in extragenic revertants. Gene 2002; 286:43-51. [PMID: 11943459 DOI: 10.1016/s0378-1119(01)00799-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have previously characterized a Saccharomyces cerevisiae mutant which contains a mutation in the essential rpn11/mpr1 gene coding for the proteasomal regulatory subunit Rpn11. The mpr1-1 mutation shows the phenotypic characteristics generally associated with proteasomal mutations, such as cell cycle defects and accumulation of polyubiquitinated proteins. However, for the first time, mitochondrial defects have also been found to be a consequence of a mutation in a proteasomal gene (Mol. Biol. Cell 9 (1998) 2917-2931). Since the mutant strain is thermosensitive both on glucose and on glycerol, we searched for revertants in order to shed light on the Rpn11/Mpr1 functions. Spontaneous revertants able to grow on glucose but not on glycerol at 36 degrees C were isolated, and, only from them, revertants able to grow at 36 degrees C on glycerol were selected. Revertants of the two classes were found to be extragenic. The detailed characterization of these extragenic suppressors demonstrates that the phenotypes related to cell cycle defects can be dissociated from those concerned with mitochondrial organization.
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Affiliation(s)
- T Rinaldi
- Department of Cell and Developmental Biology, Pasteur Institute Cenci Bolognetti Foundation, University of Rome I, Piazzale Aldo Moro 5, 00185 Rome, Italy.
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Spadaro A, Rinaldi T, Riccieri V, Taccari E, Valesini G. Interleukin-13 in autoimmune rheumatic diseases: relationship with the autoantibody profile. Clin Exp Rheumatol 2002; 20:213-6. [PMID: 12051401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVE Several cytokines play a role in the production of autoantibodies such as RF and ANA by B-lymphocytes; the role of IL-13 in this process has not been previously studied. We investigated the relationship between the serum concentration of this cytokine and circulating autoantibodies. METHODS IL-13 serum levels, as well as RF and ANA, were evaluated in 282 patients with autoimmune rheumatic diseases including RA (n=84), SLE (n= 114), SS (n=52) and Scl (n=32). RESULTS Serum levels of IL-13 (pg/ml) were significantly higher in patients with RA (p < 0.00003), SLE (p < 0.03), SS (p < 0.0007), or Scl (p < 0.025) compared to controls. IL-13 serum levels correlated with those of RF in RA (p < 0.00001), SLE (p < 0.003) and Scl (p < 0.03). IL-13 levels were higher in RA (p<0.0003), SLE (p<0.005) and Scl (p<0.05) patients with RF than in patients without RF. SS patients with antiSSA/Ro antibodies had significantly higher IL-13 levels than SS patients without this autoantibody (p < 0.04). No statistically significant correlation was found between IL-13 levels and any other antinuclear autoantibody, total immunoglobulin levels or the main clinicalfeatures of each disease. CONCLUSION The evidence of higher IL-13 levels in our RA, SLE, SS and Scl patients confirms that this cytokine is involved in the pathogenesis of autoimmune rheumatic diseases. The relationship of this cytokine with RF in RA, SLE and Scl, as well as with antiSSA/ Ro antibody in SS, strengthens the hypothesis that it plays a role in autoantibody production. However, the different autoantibody synthesis by B-cells recognises different pathways depending on the underlying autoimmune disease.
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Affiliation(s)
- A Spadaro
- Department of Medical Therapy, University of Rome La Sapienza, Italy
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11
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Abstract
OBJECTIVES To compare the pattern of interleukin (IL) 13 production in synovial fluid (SF) and serum of patients with psoriatic arthritis (PsA) with that in patients with rheumatoid arthritis (RA) and osteoarthritis (OA), investigating its relation to the proinflammatory cytokine IL12. METHODS SF and serum IL13 levels were determined in 35 patients with PsA, 36 with RA, and 15 with OA. The main clinical and laboratory variables, including number of painful and/or swollen joints, Ritchie index, morning stiffness, erythrocyte sedimentation rate, level of C reactive protein, level of rheumatoid factor, and SF analysis, were also evaluated. RESULTS SF IL13 levels were significantly higher in patients with PsA (p<0.02) or RA (p<0.012) than in patients with OA, with no significant difference between the former two. SF IL12 levels were significantly higher in patients with PsA (p<0.023) than in those with OA. Serum IL13 (p<0.0001) and IL12 (p<0.02) levels were lower in patients with PsA than in those affected by RA. Only patients with PsA had higher IL13 levels in SF than in serum (p<0.002). The IL13 SF/serum ratio was higher in the PsA group than in the group with RA (p<0.005) or OA (p<0.026). SF IL13 levels correlated with serum IL13 levels (p<0.0001) in RA and with SF IL12 levels (p<0.03) in PsA. CONCLUSIONS In PsA, there appears to be localised production of IL13, in balance with IL12, in the inflamed joints. The distinct IL13 secretion profiles in PsA, RA, and OA may be related to the clinical pictures, reflecting the different pathogenic mechanisms involved in inflammatory and degenerative joint diseases.
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Affiliation(s)
- A Spadaro
- Department of Medical Therapy, Rheumatology Unit, University of Rome La Sapienza, Italy.
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Rinaldi T, Spadaro A, Riccieri V, Taccari E, Valesini G. Interleukin-13 (IL-13)in autoimmune rheumatic diseases: relationship with autoantibody profile. Arthritis Res Ther 2001. [PMCID: PMC3273291 DOI: 10.1186/ar191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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13
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Rohou H, Francisci S, Rinaldi T, Frontali L, Bolotin-Fukuhara M. Reintroduction of a characterized Mit tRNA glycine mutation into yeast mitochondria provides a new tool for the study of human neurodegenerative diseases. Yeast 2001; 18:219-27. [PMID: 11180455 DOI: 10.1002/1097-0061(200102)18:3<219::aid-yea651>3.0.co;2-c] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We report the identification and characterization of a new mutation (ts9) in the Saccharomyces cerevisiae mitochondrial genome, which was first genetically mapped in the tRNAgly region and further identified by means of sequencing as consisting of a G to A transition at position 30 in the tRNA. The mutation causes an almost complete disappearance of mature tRNAgly, while a second mitochondrial mutation with a compensatory C to T change restores it in normal quantities; this points to the importance of the strong bond between bases 30 and 40 of the anticodon stem in the stabilization of the tRNA. In addition to resulting in a clear-cut heat-sensitive phenotype, the ts9 mutation creates a new EcoRV restriction site. Both properties were used as markers to monitor the successful (re) introduction of the mutated allele into a wild-type mitochondrial genome through biolistic transformation. The mutant frequency in the progeny as well as the correct integration of the mutated allele at its proper site demonstrate the feasibility of this method for creating and investigating specific mitochondrial tRNA mutations. The method will provide important applications for the use of yeast as a model system of human mitochondrial pathologies.
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MESH Headings
- Bacterial Proteins
- Base Sequence
- Biolistics
- Blotting, Northern
- Blotting, Southern
- DNA, Mitochondrial/chemistry
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/physiology
- Deoxyribonucleases, Type II Site-Specific/chemistry
- Genome, Fungal
- Hot Temperature
- Humans
- Mitochondria/genetics
- Molecular Sequence Data
- Neurodegenerative Diseases/genetics
- Peptide Elongation Factor Tu
- Point Mutation/physiology
- RNA/chemistry
- RNA/genetics
- RNA, Fungal/genetics
- RNA, Mitochondrial
- RNA, Transfer, Gly/chemistry
- RNA, Transfer, Gly/genetics
- Saccharomyces cerevisiae/chemistry
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/growth & development
- Sequence Analysis, DNA
- Transformation, Genetic
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Affiliation(s)
- H Rohou
- Laboratoire de Génétique Moléculaire, Institut de Génétique et Microbiologie, UMR 8621 CNRS, Université Paris-Sud, Bat. 400, 91405 Orsay Cedex, France
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14
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Abstract
Bone ultrasound parameters at the proximal phalanges of the hands were measured in 55 male patients with psoriatic arthritis (PA) (39 with peripheral radiologic involvement and 16 with axial involvement), comparing the findings with those in 16 rheumatoid arthritis (RA) patients, 20 ankylosing spondylitis (AS) patients and 55 age- and sex-matched normal controls. Mean values of amplitude-dependent speed of sound (Ad-SoS) and ultrasound bone profile score (UBPS) were significantly lower in RA (p < 0.001 and p < 1 x 10(-5)) and PA (p < 0.03 and p < 1 x 10(-6)) patients than in controls, while there was no statistically significant difference between AS patients and healthy subjects. Ultrasound parameters showed a significant negative correlation with age in all groups. In each patient group ultrasound values were unrelated either to disease duration or to inflammatory indices such as erythrocyte sedimentation rate and C-reactive protein. Moreover no significant differences were observed between ultrasound parameters of the dominant and the nondominant hand. PA patients with and without axial radiologic changes did not show any differences in ultrasound parameters. However, PA subjects with peripheral involvement only had significantly higher Ad-SoS (p < 0.04) and UBPS (p < 0.04) values than RA patients. PA patients with axial lesions had significantly lower (p < 0.04 and p < 0.01) ultrasound values than AS patients. These findings suggest that PA ultrasound techniques performed at the peripheral level are of value to speculate on bone involvement, although we think that ultrasound measurements cannot yet be recommended for monitoring bone involvement in these patients.
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Affiliation(s)
- E Taccari
- Department of Medical Therapy, Rheumatology Unit, University La Sapienza, Rome, Italy
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15
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Spadaro A, Riccieri V, Terracina S, Rinaldi T, Taccari E, Zoppini A. Class specific rheumatoid factors and antiphospholipid syndrome in systemic lupus erythematosus. Lupus 2000; 9:56-60. [PMID: 10713647 DOI: 10.1177/096120330000900110] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The relationship of rheumatoid factors (RF) with antiphospholipid syndrome (aPLS) and anticardiolipin antibodies (aCL) has rarely been investigated in systemic lupus erythematosus (SLE). We found IgM-RF, IgG-RF, IgA-RF, IgM-aCL, IgG-aCL, IgA-aCL, respectively, in 35.4%, 35.4%, 33.8%, 23.1%, 23.1%, 20.0% of 65 SLE patients. Class specific RFs were negatively associated (P<0.05) with IgG-aCL. The frequency of definite or probable aPLS according to Alarcon-Segovia classification criteria was significantly (P<0.05) different (8.7% vs 30.9%) in patients with or without IgG-RF. Among the other clinical features of SLE, we found that patients with IgG-RF, compared to patients lacking this autoantibody, showed a lower frequency (P<0.05) of serositis (21.7% vs 52.4%) and hematologic (52. 2% vs 80.9%) disorders. The levels of IgG-RF and IgM-RF negatively correlated with the number of ARA criteria (P<0.05) but not with the indices of diseases activity or damage. Our study shows that in SLE the presence of RFs are not markers of severity of the disease, but the negative association between IgG-RF and IgG-aCL suggests a distinct role of these autoantibodies in the pathology of SLE, whereas the presence of IgG isotype may identify a subset of SLE patients having a lower risk to develop some clinical manifestations such as aPLS.
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Affiliation(s)
- A Spadaro
- Department of Medical Therapy, Rheumatology Unit, University of Rome "La Sapienza", Rome, Italy
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16
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Taccari E, Spadaro A, Rinaldi T, Riccieri V, Sensi F. Comparison of the Health Assessment Questionnaire and Arthritis Impact Measurement Scale in patients with psoriatic arthritis. Rev Rhum Engl Ed 1998; 65:751-8. [PMID: 9923043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
OBJECTIVE To determine which of two instruments, the Health Assessment Questionnaire (HAQ) and the Arthritis Impact Measurement Scales (AIMS), was more closely correlated with the main parameters reflecting activity and severity of psoriatic arthritis. METHODS Both instruments were administered to 72 consecutive patients with psoriatic arthritis. RESULTS Global HAQ and AIMS scores were closely correlated with each other (rs = 0.747; P < 0.00001). AIMS physical function scales--namely physical activity, dexterity, social activity and activities of daily living--were moderately or closely correlated with the main clinical disease activity parameters, most notably morning stiffness of axial joints (rs = 0.271-0.551). Scales measuring psychological status yielded weaker correlations with disease activity parameters (rs = 0.241-0.277) and were also correlated with the visual analog scale score for skin lesion severity. Morning stiffness of peripheral joints was correlated only with two AIMS scales, namely pain (rs = 0.532) and activities of daily living (rs = 0.303). Severity of radiological damage of peripheral and axial joints was most closely correlated with the scales of physical function, most notably physical activity. The global and scale HAQ scores showed moderate to close correlations with the main clinical disease activity parameters, most notably morning stiffness of axial joints. The global HAQ score was also correlated with radiological carpal involvement and with the radiological severity of peripheral joint involvement, whereas only the arising and hygiene scales were (moderately) correlated with the radiological severity of spinal involvement. CONCLUSION Although both the HAQ and the AIMS were useful in assessing health status in psoriatic arthritis patients, only the AIMS captured some of the effects of the skin lesions. Our data also suggest that the AIMS may be more effective than the HAQ for evaluating the effect of radiological lesions produced by psoriatic arthritis.
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Affiliation(s)
- E Taccari
- Rheumatology Institute La Sapienza University, Rome, Italy
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17
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Rinaldi T, Ricci C, Porro D, Bolotin-Fukuhara M, Frontali L. A mutation in a novel yeast proteasomal gene, RPN11/MPR1, produces a cell cycle arrest, overreplication of nuclear and mitochondrial DNA, and an altered mitochondrial morphology. Mol Biol Cell 1998; 9:2917-31. [PMID: 9763452 PMCID: PMC25568 DOI: 10.1091/mbc.9.10.2917] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We report here the functional characterization of an essential Saccharomyces cerevisiae gene, MPR1, coding for a regulatory proteasomal subunit for which the name Rpn11p has been proposed. For this study we made use of the mpr1-1 mutation that causes the following pleiotropic defects. At 24 degreesC growth is delayed on glucose and impaired on glycerol, whereas no growth is seen at 36 degreesC on either carbon source. Microscopic observation of cells growing on glucose at 24 degreesC shows that most of them bear a large bud, whereas mitochondrial morphology is profoundly altered. A shift to the nonpermissive temperature produces aberrant elongated cell morphologies, whereas the nucleus fails to divide. Flow cytometry profiles after the shift to the nonpermissive temperature indicate overreplication of both nuclear and mitochondrial DNA. Consistently with the identification of Mpr1p with a proteasomal subunit, the mutation is complemented by the human POH1 proteasomal gene. Moreover, the mpr1-1 mutant grown to stationary phase accumulates ubiquitinated proteins. Localization of the Rpn11p/Mpr1p protein has been studied by green fluorescent protein fusion, and the fusion protein has been found to be mainly associated to cytoplasmic structures. For the first time, a proteasomal mutation has also revealed an associated mitochondrial phenotype. We actually showed, by the use of [rho degrees] cells derived from the mutant, that the increase in DNA content per cell is due in part to an increase in the amount of mitochondrial DNA. Moreover, microscopy of mpr1-1 cells grown on glucose showed that multiple punctate mitochondrial structures were present in place of the tubular network found in the wild-type strain. These data strongly suggest that mpr1-1 is a valuable tool with which to study the possible roles of proteasomal function in mitochondrial biogenesis.
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Affiliation(s)
- T Rinaldi
- Pasteur Institute-Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome "La Sapienza", 00185 Rome, Italy. Rinaldit.axcasp.caspur.it
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18
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Rinaldi T, Lande R, Bolotin-Fukuhara M, Frontali L. Additional copies of the mitochondrial Ef-Tu and aspartyl-tRNA synthetase genes can compensate for a mutation affecting the maturation of the mitochondrial tRNAAsp. Curr Genet 1997; 31:494-6. [PMID: 9211792 DOI: 10.1007/s002940050235] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In an attempt to identify new nuclear genes involved in the synthesis and processing of mitochondrial tRNAs, we utilized a multicopy nuclear library to suppress the heat-sensitive phenotype of a Saccharomyces cerevisiae mitochondrial mutant strain. This strain (Ts 932) is defective in the 3'-end processing of the mitochondrial tRNAAsp transcript. The nuclear genes coding for the mitochondrial elongation factor Tuf M and for the mitochondrial aspartyl-tRNA synthetase have been found to restore the temperature-resistant phenotype and to correct the RNA processing defect. Suppression was effective even when the genes were present on a centromeric plasmid.
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Affiliation(s)
- T Rinaldi
- Pasteur Institute-Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome I, I-00185 Rome, Italy
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19
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Mazzoni C, Ruzzi M, Rinaldi T, Solinas F, Montebove F, Frontali L. Sequence analysis of a 10.5 kb DNA fragment from the yeast chromosome VII reveals the presence of three new open reading frames and of a tRNAThr gene. Yeast 1997; 13:369-72. [PMID: 9133741 DOI: 10.1002/(sici)1097-0061(19970330)13:4<369::aid-yea81>3.0.co;2-v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We report the sequence analysis of a 10,531 bp DNA of Saccharomyces cerevisiae chromosome VII. This sequence contains five complete open reading frames (ORFs) potentially encoding proteins longer than 100 amino acids and incomplete ORF encoding for the 3' part of the GCN5 gene (Georgakopoulos and Thireos, 1992). ORFs G9160 and G9155 correspond to the genes ENO1 (Holland et al. 1981) and PUP2 (Gergatsou et al., 1992) respectively. ORF G9165 codes for a protein which shares significant homology with known proteins present in databases (see below). The translated sequence of ORF G9170 shows 88% identity to the 6-phosphogluconate dehydrogenase encoded by the gene 6PGD from S. cerevisiae present in the SwissProt data library (P38720). This indicates that G9170 might code for a second 6-phosphogluconate dehydrogenase. ORF G9175 codes for a putative new member of the mitochondrial carrier family. A hypothetical tRNAThr (TGT) is also present in position 6842-6913.
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Affiliation(s)
- C Mazzoni
- Department of Cell and Developmental Biology, University of Rome La Sapienza, Italy
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20
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Cardazzo B, Rinaldi T, Frontali L, Carignani G, Palleschi C. Evolution of mitochondrial genomes in yeast: a study of mitochondrial divergence in two closely related species, Saccharomyces douglasii and Saccharomyces cerevisiae. Mol Biol Evol 1997; 14:200-3. [PMID: 9029799 DOI: 10.1093/oxfordjournals.molbev.a025754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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21
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Abstract
To identify the gene coding for the endonuclease which processes the 3' end of mitochondrial (mt) tRNA transcripts in Saccharomyces cerevisiae, nuclear mutations able to complement a mt mutant (Ts932) defective for this process were isolated and analyzed. One of these mutants exhibited a growth defect both on respiratory and fermentable media. Complementation of this phenotype with a S. cerevisiae centrometric wild-type genomic library has allowed us to identify a new essential S. cerevisiae gene strongly conserved in various eukaryotic organisms.
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Affiliation(s)
- T Rinaldi
- Pasteur Institute-Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome, Italy
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22
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Rinaldi T, Francisci S, Zennaro E, Frontali L, Bolotin-Fukuhara M. Suppression of a mitochondrial point mutation in a tRNA gene can cast light on the mechanisms of 3' end-processing. Curr Genet 1994; 25:451-5. [PMID: 7521797 DOI: 10.1007/bf00351785] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We used a genetic approach to study the nuclear factors involved in the biogenesis of mitochondrial tRNAs. A point mutation in the mitochondrial tRNA(Asp) gene of Saccharomyces cerevisiae had previously been shown to result in a temperature-sensitive respiratory-deficient phenotype as a result of the absence of 3' end-processing of the tRNA(Asp). Analysis of mitochondrial revertants has shown that all revertants sequenced have a G-A compensatory change at position 53, which restores the hydrogen-bond with the mutated nucleotide. We then searched for nuclear suppressors to identify the nuclear gene(s) involved in mitochondrial tRNA 3' end-processing. One such suppressor mutation was further characterized: it restores tRNA(Asp) maturation and growth at 36 degrees C on glycerol medium in heterozygous diploids, but leads to a defective growth phenotype in haploids.
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MESH Headings
- Base Sequence
- Diploidy
- Genes, Fungal
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phenotype
- Point Mutation
- RNA/chemistry
- RNA/genetics
- RNA/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Mitochondrial
- RNA, Transfer, Asp/chemistry
- RNA, Transfer, Asp/genetics
- RNA, Transfer, Asp/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Suppression, Genetic
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Affiliation(s)
- T Rinaldi
- Laboratoire de Génétique Moléculaire, Université Paris-Sud, Orsay, France
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23
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Valens M, Rinaldi T, Daignan-Fornier B, Bolotin-Fukuhara M. Identification of nuclear genes which participate to mitochondrial translation in Saccharomyces cerevisiae. Biochimie 1991; 73:1525-32. [PMID: 1725263 DOI: 10.1016/0300-9084(91)90187-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mitochondrial protein synthesis presents specific features and uses specific components different from their cytoplasmic counterparts. Since most genes which code for these components are localized in the chromosomes and only a small number are encoded by the mitochondrial DNA, it is important to identify and characterize the nuclear genes involved in this process. In order to do this, we have used a genetic screening which implies the selection and study of nuclear suppressors of mitochondrial mutations (or the reverse situation) which affect the mitochondrial protein synthesis. Three mutations have been used for this purpose. Two of them (ts 1398, cs 909) impair the mitochondrial ribosome; they were used to characterize new interacting components as well as two genes, MBR1 and MBR2, which control the assembly or the regulation of other genes involved in mitochondrial protein synthesis. The third mutation (ts 932), blocks the 3'-end maturation of the mitochondrial aspartyl tRNA. A nuclear suppressor has been obtained which presents all the characteristics of a mutation in the gene encoding the enzyme responsible for this process.
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Affiliation(s)
- M Valens
- Laboratoire de génétique moléculaire, institut de génétique et microbiologie associé au CNRS, université Paris, Orsay, France
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24
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Tian GL, Macadre C, Kruszewska A, Szczesniak B, Ragnini A, Grisanti P, Rinaldi T, Palleschi C, Frontali L, Slonimski PP. Incipient mitochondrial evolution in yeasts. I. The physical map and gene order of Saccharomyces douglasii mitochondrial DNA discloses a translocation of a segment of 15,000 base-pairs and the presence of new introns in comparison with Saccharomyces cerevisiae. J Mol Biol 1991; 218:735-46. [PMID: 1850804 DOI: 10.1016/0022-2836(91)90262-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have determined the physical and genetic map of the 73,000 base-pair mitochondrial genome of a novel yeast species Saccharomyces douglasii. Most of the protein and RNA-coding genes known to be present in the mitochondrial DNA of Saccharomyces cerevisiae have been identified and located on the S. douglasii mitochondrial genome. The nuclear genomes of the two species are thought to have diverged some 50 to 80 million years ago and their nucleo-mitochondrial hybrids are viable but respiratorily deficient. The mitochondrial genome of S. douglasii displays many interesting features in comparison with that of S. cerevisiae. The three mosaic genes present in both genomes are quite different with regard to their structure. The S. douglasii COXI gene has two new introns and is missing the five introns of the S. cerevisiae gene. The S. douglasii cytochrome b gene has one new intron and lacks two introns of the S. cerevisiae gene. Finally, the L-rRNA gene of S. douglasii, like that of S. cerevisiae, has one intron of which the structure is different. Another salient feature of the S. douglasii mitochondrial genome reported here is that the gene order is different in comparison with S. cerevisiae mitochondrial DNA. In particular, a segment of approximately 15,000 base-pairs including the genes coding for COXIII and S-rRNA has been translocated to a position between the genes coding for varl and L-rRNA.
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Affiliation(s)
- G L Tian
- Centre de Génétique Moléculaire du C.N.R.S., Laboratoire Propre Associé à l'Université Pierre et Marie Curie, Gif-sur-Yvette, France
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25
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Ragnini A, Grisanti P, Rinaldi T, Frontali L, Palleschi C. Mitochondrial genome of Saccharomyces douglasii: genes coding for components of the protein synthetic apparatus. Curr Genet 1991; 19:169-74. [PMID: 1868570 DOI: 10.1007/bf00336483] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mitochondrial genes coding for some components of the protein synthetic apparatus in S. douglasii have been studies in detail. A region containing stretches of high homology to the S. cerevisiae tRNA synthesis locus (TSL) and the tRNA(fmet) gene has been identified and sequenced. The organization of this region was very similar to that present in S. cerevisiae, including the presence of a possible transcription starting signal. The S. douglasii TSL gene is shorter due to several deletions which, however, do not involve the regions coding for RNA domains know to be required for the catalytic activity of mitochondrial RNAse P. The S. douglasii LSU rRNA gene has been shown to contain a typical group I intron highly homologous to its S. cerevisiae counterpart, except for the absence of the open reading frame which in S. cerevisiae codes for I-SceI endonuclease.
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Affiliation(s)
- A Ragnini
- Department of Cell and Developmental Biology, University of Rome, Italy
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