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Shi H, Meng S, Qiu J, Xie S, Jiang N, Luo C, Naqvi NI, Kou Y. MoAti1 mediates mitophagy by facilitating recruitment of MoAtg8 to promote invasive growth in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2024; 25:e13439. [PMID: 38483039 PMCID: PMC10938464 DOI: 10.1111/mpp.13439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 01/18/2024] [Accepted: 02/03/2024] [Indexed: 03/17/2024]
Abstract
Mitophagy is a selective autophagy for the degradation of damaged or excessive mitochondria to maintain intracellular homeostasis. In Magnaporthe oryzae, a filamentous ascomycetous fungus that causes rice blast, the most devastating disease of rice, mitophagy occurs in the invasive hyphae to promote infection. To date, only a few proteins are known to participate in mitophagy and the mechanisms of mitophagy are largely unknown in pathogenic fungi. Here, by a yeast two-hybrid screen with the core autophagy-related protein MoAtg8 as a bait, we obtained a MoAtg8 interactor MoAti1 (MoAtg8-interacting protein 1). Fluorescent observations and protease digestion analyses revealed that MoAti1 is primarily localized to the peripheral mitochondrial outer membrane and is responsible for recruiting MoAtg8 to mitochondria under mitophagy induction conditions. MoAti1 is specifically required for mitophagy, but not for macroautophagy and pexophagy. Infection assays suggested that MoAti1 is required for mitophagy in invasive hyphae during pathogenesis. Notably, no homologues of MoAti1 were found in rice and human protein databases, indicating that MoAti1 may be used as a potential target to control rice blast. By the host-induced gene silencing (HIGS) strategy, transgenic rice plants targeted to silencing MoATI1 showed enhanced resistance against M. oryzae with unchanged agronomic traits. Our results suggest that MoATI1 is required for mitophagy and pathogenicity in M. oryzae and can be used as a target for reducing rice blast.
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Affiliation(s)
- Huanbin Shi
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
| | - Shuai Meng
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
| | - Jiehua Qiu
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
| | - Shuwei Xie
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
| | - Nan Jiang
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
| | - Chaoxi Luo
- Key Lab of Horticultural Plant Biology, Ministry of Education, and College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Naweed I. Naqvi
- Temasek Life Sciences Laboratory, Department of Biological SciencesNational University of SingaporeSingapore
| | - Yanjun Kou
- State Key Lab of Rice Biology and BreedingChina National Rice Research InstituteHangzhouChina
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Porras-Agüera JA, Mauricio JC, Moreno-García J, Moreno J, García-Martínez T. A Differential Proteomic Approach to Characterize the Cell Wall Adaptive Response to CO 2 Overpressure during Sparkling Wine-Making Process. Microorganisms 2020; 8:E1188. [PMID: 32759881 PMCID: PMC7465653 DOI: 10.3390/microorganisms8081188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/28/2020] [Accepted: 08/02/2020] [Indexed: 11/16/2022] Open
Abstract
In this study, a first proteomic approach was carried out to characterize the adaptive response of cell wall-related proteins to endogenous CO2 overpressure, which is typical of second fermentation conditions, in two wine Saccharomyces cerevisiae strains (P29, a conventional second fermentation strain, and G1, a flor yeast strain implicated in sherry wine making). The results showed a high number of cell wall proteins in flor yeast G1 under pressure, highlighting content at the first month of aging. The cell wall proteomic response to pressure in flor yeast G1 was characterized by an increase in both the number and content of cell wall proteins involved in glucan remodeling and mannoproteins. On the other hand, cell wall proteins responsible for glucan assembly, cell adhesion, and lipid metabolism stood out in P29. Over-represented proteins under pressure were involved in cell wall integrity (Ecm33p and Pst1p), protein folding (Ssa1p and Ssa2p), and glucan remodeling (Exg2p and Scw4p). Flocculation-related proteins were not identified under pressure conditions. The use of flor yeasts for sparkling wine elaboration and improvement is proposed. Further research based on the genetic engineering of wine yeast using those genes from protein biomarkers under pressure alongside the second fermentation in bottle is required to achieve improvements.
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Affiliation(s)
- Juan Antonio Porras-Agüera
- Department of Microbiology, Agrifood Campus of International Excellence ceiA3, C6 building, Campus de Rabanales, University of Córdoba, E-14014 Córdoba, Spain; (J.A.P.-A.); (J.M.-G.); (T.G.-M.)
| | - Juan Carlos Mauricio
- Department of Microbiology, Agrifood Campus of International Excellence ceiA3, C6 building, Campus de Rabanales, University of Córdoba, E-14014 Córdoba, Spain; (J.A.P.-A.); (J.M.-G.); (T.G.-M.)
| | - Jaime Moreno-García
- Department of Microbiology, Agrifood Campus of International Excellence ceiA3, C6 building, Campus de Rabanales, University of Córdoba, E-14014 Córdoba, Spain; (J.A.P.-A.); (J.M.-G.); (T.G.-M.)
| | - Juan Moreno
- Department of Agricultural Chemistry, Agrifood Campus of International Excellence ceiA3, C3 building, Campus de Rabanales, University of Córdoba, E-14014 Córdoba, Spain;
| | - Teresa García-Martínez
- Department of Microbiology, Agrifood Campus of International Excellence ceiA3, C6 building, Campus de Rabanales, University of Córdoba, E-14014 Córdoba, Spain; (J.A.P.-A.); (J.M.-G.); (T.G.-M.)
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Pagano L, Caldara M, Villani M, Zappettini A, Marmiroli N, Marmiroli M. In Vivo-In Vitro Comparative Toxicology of Cadmium Sulphide Quantum Dots in the Model Organism Saccharomyces cerevisiae. NANOMATERIALS 2019; 9:nano9040512. [PMID: 30986968 PMCID: PMC6523553 DOI: 10.3390/nano9040512] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 12/22/2022]
Abstract
The aim of this work was to use the yeast Saccharomyces cerevisiae as a tool for toxicogenomic studies of Engineered Nanomaterials (ENMs) risk assessment, in particular focusing on cadmium based quantum dots (CdS QDs). This model has been exploited for its peculiar features: a short replication time, growth on both fermentable and oxidizable carbon sources, and for the contextual availability of genome wide information in the form of genetic maps, DNA microarray, and collections of barcoded mutants. The comparison of the whole genome analysis with the microarray experiments (99.9% coverage) and with the phenotypic analysis of 4688 barcoded haploid mutants (80.2% coverage), shed light on the genes involved in the response to CdS QDs, both in vivo and in vitro. The results have clarified the mechanisms involved in the exposure to CdS QDs, and whether these ENMs and Cd2+ exploited different pathways of response, in particular related to oxidative stress and to the maintenance of mitochondrial integrity and function. Saccharomyces cerevisiae remains a versatile and robust alternative for organismal toxicological studies, with a high level of heuristic insights into the toxicology of more complex eukaryotes, including mammals.
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Affiliation(s)
- Luca Pagano
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43123 Parma, Italy.
| | - Marina Caldara
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43123 Parma, Italy.
| | | | | | - Nelson Marmiroli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43123 Parma, Italy.
- Consorzio Interuniversitario Nazionale per le Scienze Ambientali (CINSA), University of Parma, 43123 Parma, Italy.
| | - Marta Marmiroli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43123 Parma, Italy.
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Pérez-Hernández A, González M, González C, van Kan JAL, Brito N. BcSUN1, a B. cinerea SUN-Family Protein, Is Involved in Virulence. Front Microbiol 2017; 8:35. [PMID: 28163701 PMCID: PMC5247446 DOI: 10.3389/fmicb.2017.00035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/06/2017] [Indexed: 12/31/2022] Open
Abstract
BcSUN1 is a glycoprotein secreted by Botrytis cinerea, an important plant pathogen that causes severe losses in agriculture worldwide. In this work, the role of BcSUN1 in different aspects of the B. cinerea biology was studied by phenotypic analysis of Bcsun1 knockout strains. We identified BcSUN1 as the only member of the Group-I SUN family of proteins encoded in the B. cinerea genome, which is expressed both in axenic culture and during infection. BcSUN1 is also weakly attached to the cellular surface and is involved in maintaining the structure of the cell wall and/or the extracellular matrix. Disruption of the Bcsun1 gene produces different cell surface alterations affecting the production of reproductive structures and adhesion to plant surface, therefore reducing B. cinerea virulence. BcSUN1 is the first member of the SUN family reported to be involved in the pathogenesis of a filamentous fungus.
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Affiliation(s)
- Alicia Pérez-Hernández
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna (ULL)La Laguna, Spain
| | - Mario González
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna (ULL)La Laguna, Spain
| | - Celedonio González
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna (ULL)La Laguna, Spain
| | - Jan A. L. van Kan
- Laboratory of Phytopathology, Department of Plant Sciences, Wageningen University and Research Centre (WUR)Wageningen, Netherlands
| | - Nélida Brito
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna (ULL)La Laguna, Spain
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Yu M, Yu J, Hu J, Huang L, Wang Y, Yin X, Nie Y, Meng X, Wang W, Liu Y. Identification of pathogenicity-related genes in the rice pathogen Ustilaginoidea virens through random insertional mutagenesis. Fungal Genet Biol 2015; 76:10-9. [DOI: 10.1016/j.fgb.2015.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 12/31/2014] [Accepted: 01/16/2015] [Indexed: 10/24/2022]
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Abstract
Productive cell proliferation involves efficient and accurate splitting of the dividing cell into two separate entities. This orderly process reflects coordination of diverse cytological events by regulatory systems that drive the cell from mitosis into G1. In the budding yeast Saccharomyces cerevisiae, separation of mother and daughter cells involves coordinated actomyosin ring contraction and septum synthesis, followed by septum destruction. These events occur in precise and rapid sequence once chromosomes are segregated and are linked with spindle organization and mitotic progress by intricate cell cycle control machinery. Additionally, critical paarts of the mother/daughter separation process are asymmetric, reflecting a form of fate specification that occurs in every cell division. This chapter describes central events of budding yeast cell separation, as well as the control pathways that integrate them and link them with the cell cycle.
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Hiller E, Heine S, Brunner H, Rupp S. Candida albicans Sun41p, a putative glycosidase, is involved in morphogenesis, cell wall biogenesis, and biofilm formation. EUKARYOTIC CELL 2007; 6:2056-65. [PMID: 17905924 PMCID: PMC2168408 DOI: 10.1128/ec.00285-07] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The SUN gene family has been defined in Saccharomyces cerevisiae and comprises a fungus-specific family of proteins which show high similarity in their C-terminal domains. Genes of this family are involved in different cellular processes, like DNA replication, aging, mitochondrial biogenesis, and cytokinesis. In Candida albicans the SUN family comprises two genes, SUN41 and SIM1. We demonstrate that C. albicans mutants lacking SUN41 show similar defects as found for S. cerevisiae, including defects in cytokinesis. In addition, the SUN41 mutant showed a higher sensitivity towards the cell wall-disturbing agent Congo red, whereas no difference was observed in the presence of calcofluor white. Compared to the wild type, SUN41 deletion strains exhibited a defect in biofilm formation, a reduced adherence on a Caco-2 cell monolayer, and were unable to form hyphae on solid medium under the conditions tested. Interestingly, Sun41p was found to be secreted in the medium of cells growing as blastospores as well as those forming hyphae. Our results support a function of SUN41p as a glycosidase involved in cytokinesis, cell wall biogenesis, adhesion to host tissue, and biofilm formation, indicating an important role in the host-pathogen interaction.
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Affiliation(s)
- Ekkehard Hiller
- Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstrasse 12, 70569 Stuttgart, Germany
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Norice CT, Smith FJ, Solis N, Filler SG, Mitchell AP. Requirement for Candida albicans Sun41 in biofilm formation and virulence. EUKARYOTIC CELL 2007; 6:2046-55. [PMID: 17873081 PMCID: PMC2168420 DOI: 10.1128/ec.00314-07] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The cell wall of Candida albicans lies at the crossroads of pathogenicity and therapeutics. It contributes to pathogenicity through adherence and invasion; it is the target of both chemical and immunological antifungal strategies. We have initiated a dissection of cell wall function through targeted insertional mutagenesis of cell wall-related genes. Among 25 such genes, we were unable to generate homozygous mutations in 4, and they may be essential for viability. We created homozygous mutations in the remaining 21 genes. Insertion mutations in SUN41, Orf19.5412, Orf19.1277, MSB2, Orf19.3869, and WSC1 caused hypersensitivity to the cell wall inhibitor caspofungin, while two different ecm33 insertions caused mild caspofungin resistance. Insertion mutations in SUN41 and Orf19.5412 caused biofilm defects. Through analysis of homozygous sun41Delta/sun41Delta deletion mutants and sun41Delta/sun41Delta+pSUN41-complemented strains, we verified that Sun41 is required for biofilm formation and normal caspofungin tolerance. The sun41Delta/sun41Delta mutant had altered expression of four cell wall damage response genes, thus suggesting that it suffers a cell wall structural defect. Sun41 is required for inducing disease, because the mutant was severely attenuated in mouse models of disseminated and oropharyngeal candidiasis. Although the mutant produced aberrant hyphae, it had no defect in damaging endothelial or epithelial cells, unlike many other hypha-defective mutants. We suggest that the sun41Delta/sun41Delta cell wall defect is the primary cause of its attenuated virulence. As a small fungal surface protein with predicted glucosidase activity, Sun41 represents a promising therapeutic target.
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Larsen P, Almasri E, Chen G, Dai Y. A statistical method to incorporate biological knowledge for generating testable novel gene regulatory interactions from microarray experiments. BMC Bioinformatics 2007; 8:317. [PMID: 17727721 PMCID: PMC2082045 DOI: 10.1186/1471-2105-8-317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 08/29/2007] [Indexed: 11/16/2022] Open
Abstract
Background The incorporation of prior biological knowledge in the analysis of microarray data has become important in the reconstruction of transcription regulatory networks in a cell. Most of the current research has been focused on the integration of multiple sets of microarray data as well as curated databases for a genome scale reconstruction. However, individual researchers are more interested in the extraction of most useful information from the data of their hypothesis-driven microarray experiments. How to compile the prior biological knowledge from literature to facilitate new hypothesis generation from a microarray experiment is the focus of this work. We propose a novel method based on the statistical analysis of reported gene interactions in PubMed literature. Results Using Gene Ontology (GO) Molecular Function annotation for reported gene regulatory interactions in PubMed literature, a statistical analysis method was proposed for the derivation of a likelihood of interaction (LOI) score for a pair of genes. The LOI-score and the Pearson correlation coefficient of gene profiles were utilized to check if a pair of query genes would be in the above specified interaction. The method was validated in the analysis of two gene sets formed from the yeast Saccharomyces cerevisiae cell cycle microarray data. It was found that high percentage of identified interactions shares GO Biological Process annotations (39.5% for a 102 interaction enriched gene set and 23.0% for a larger 999 cyclically expressed gene set). Conclusion This method can uncover novel biologically relevant gene interactions. With stringent confidence levels, small interaction networks can be identified for further establishment of a hypothesis testable by biological experiment. This procedure is computationally inexpensive and can be used as a preprocessing procedure for screening potential biologically relevant gene pairs subject to the analysis with sophisticated statistical methods.
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Affiliation(s)
- Peter Larsen
- Core Genomics Laboratory at University of Illinois at Chicago, 845 West Taylor Street Chicago, IL 60607, USA
| | - Eyad Almasri
- Department of Bioengineering (MC063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607, USA
| | - Guanrao Chen
- Department of Computer Science, University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607, USA
| | - Yang Dai
- Department of Bioengineering (MC063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607, USA
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Camougrand N, Kissová I, Velours G, Manon S. Uth1p: a yeast mitochondrial protein at the crossroads of stress, degradation and cell death. FEMS Yeast Res 2005; 5:133-40. [PMID: 15489196 DOI: 10.1016/j.femsyr.2004.05.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Revised: 03/30/2004] [Accepted: 05/06/2004] [Indexed: 12/31/2022] Open
Abstract
UTH1 is a yeast aging gene that has been identified on the basis of stress resistance and longer life span of mutants. It was also shown to participate in mitochondrial biogenesis. The absence of Uth1p was found to trigger resistance to autophagy induced by rapamycin. Uth1p is therefore the first mitochondrial protein proven to be required for the autophagic degradation of mitochondria. Since this protein is also involved in yeast cell death induced by heterologous expression of the pro-apoptotic protein Bax, the results are discussed in the light of evidence suggesting a co-regulation of apoptosis and autophagy in mammalian cells.
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Affiliation(s)
- Nadine Camougrand
- Institut de Biochimie et Genetique, Cellulaires du CNRS, UMR5095 CNRS/Université de Bordeaux 2, 1 rue Camille Saint Saens, 33077 Bordeaux Cedex, France.
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Priault M, Camougrand N, Kinnally KW, Vallette FM, Manon S. Yeast as a tool to study Bax/mitochondrial interactions in cell death. FEMS Yeast Res 2003; 4:15-27. [PMID: 14554193 DOI: 10.1016/s1567-1356(03)00143-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae has proven to be a powerful tool in investigations of the molecular aspects of the events involved in apoptosis, particularly the steps implicating mitochondria. Yeast does not have obvious homologs of the proteins involved in the regulation of apoptosis, and provides a simplified model system in which the function of these proteins can be unraveled. This review focuses on the interactions of two of the major pro-apoptotic Bcl-2 family members, Bax and Bid, with mitochondria. It is shown that yeast has allowed questioning of several crucial aspects of the function of these two proteins, namely the molecular mechanisms driving their insertion into the mitochondrial outer membrane and those leading to the permeabilization to cytochrome c. More recently, signaling pathways leading to Bax-induced cell death, as well as other forms of cell death, have been identified in yeast. Both 'apoptosis-like' and autophagy-related forms of cell degradation are involved, and mitochondria play a central role in these two signaling pathways.
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Affiliation(s)
- Muriel Priault
- IBGC/CNRS, 1 Rue Camille Saint-Saëns, Université de Bordeaux 2, F-33077 Bordeaux, France
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Camougrand N, Grelaud-Coq A, Marza E, Priault M, Bessoule JJ, Manon S. The product of the UTH1 gene, required for Bax-induced cell death in yeast, is involved in the response to rapamycin. Mol Microbiol 2003; 47:495-506. [PMID: 12519199 DOI: 10.1046/j.1365-2958.2003.03311.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A yeast mutant was isolated that was resistant to Bax-induced cell death. It supports a mutation leading to decreased amounts of the protein Uth1p. A strain in which the UTH1 gene is disrupted also exhibits resistance to Bax expression. The absence of Uth1p does not change the mitochondrial localization of Bax, its insertion in the mitochondrial outer membrane or its cytochrome c-releasing activity. On the other hand, the absence of Uth1p does prevent the appearance of other hallmarks related to Bax expression in yeast, such as oxidation of mitochondrial lipid, production of reactive oxygen species and maintenance of plasma membrane properties after ethanol stress. The absence of Uth1p was also found to induce resistance to rapamycin, a specific inducer of autophagy. This resistance only appears when cells are grown under respiratory conditions, but not under fermentative conditions, suggesting that Uth1p acts in an autophagic pathway involving mitochondria, in accordance with its main localization in the outer mitochondrial membrane. Taken together, these data show that Bax is able to activate a death pathway related to autophagy in yeast, which also exhibits typical hallmarks of apoptosis, revealing a possible dual function of Bax in both types of death. This hypothesis is discussed in the light of observations suggesting a co-regulation of apoptosis and autophagy in mammalian cells.
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Guyard C, Cailliez JC, Tissier JP, Dei-Cas E, Mercenier A, Menozzi FD. Cloning and characterization of WMSU1, a Williopsis saturnus var. mrakii gene encoding a new yeast SUN protein involved in the cell wall structure. Yeast 2002; 19:1127-38. [PMID: 12237854 DOI: 10.1002/yea.898] [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] [Indexed: 11/06/2022] Open
Abstract
SUN proteins of Saccharomyces cerevisiae have been defined on the basis of high homologies in their C-terminal domain. Recently, two of these four proteins were shown to be involved in cell wall morphogenesis (Mouassite et al., 2000a). In the present study, we have isolated WMSU1 (Accession No. AF418983), a new SUN-related gene, from W. saturnus var. mrakii MUCL 41968. Sequencing of the gene revealed an open reading frame coding for 402 amino acids. The predicted amino acid sequence of WMSU1 is closely related to the S. cerevisiae SUN proteins and to other yeast proteins involved in cell wall metabolism. WMSU1 is proposed to encode a cell wall protein since its predicted product contains a signal sequence, a Kex2p cleavage site and a serine/threonine-rich N-terminal domain. Southern blot analysis of the W. saturnus var. mrakii MUCL 41968 genome using the highly conserved domain of WMSU1 as a probe suggested that the isolated gene belongs to a multigenic family. Expression of WMSU1 in E. coli led to a 45 kDa protein, which appeared to be toxic to this host. Scanning electron microscopy analysis of a recombinant S. cerevisiae producing Wmsu1p showed that this strain exhibited an altered cell wall, thus pointing to a probable role of this protein in the cell wall structure.
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Affiliation(s)
- Cyril Guyard
- Laboratoire de Parasitologie-Mycologie, Institut Pasteur de Lille, 1 rue Calmette, BP 245, 59019 Lille, France.
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Camougrand N, Rigoulet M. Aging and oxidative stress: studies of some genes involved both in aging and in response to oxidative stress. RESPIRATION PHYSIOLOGY 2001; 128:393-401. [PMID: 11718766 DOI: 10.1016/s0034-5687(01)00314-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aging is a complex physiological phenomenon and several theories have been developed about its origin. Among such theories, the 'mitochondrial theory of aging' has been supported by numerous studies and reviews. Cell oxidative damage, in particular the accumulation of mtDNA mutations, is determined by the rate of reactive oxygen species production and degradation induced by the antioxidant defense systems. In this review, data from our laboratory and from the recent literature have been examined to provide arguments that reinforce the crucial role of mitochondria in aging. Various genes that affect life span have been described in numerous organisms. Some of them encode signal transduction proteins and participate in the regulation of mitochondrial metabolism.
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Affiliation(s)
- N Camougrand
- Institut de Biochimie et Genetique Cellulaires du CNRS, 1 rue Camille Saint Saëns, 33077 Cedex, Bordeaux, France.
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Mouassite M, Camougrand N, Schwob E, Demaison G, Laclau M, Guérin M. The 'SUN' family: yeast SUN4/SCW3 is involved in cell septation. Yeast 2000; 16:905-19. [PMID: 10870102 DOI: 10.1002/1097-0061(200007)16:10<905::aid-yea584>3.0.co;2-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
SUN4 is the fourth member of the SUN gene family from S. cerevisiae, whose products display high homology in their 258 amino acid C-terminal domain. SIM1, UTH1, NCA3 (the founding members) are involved in different cellular processes (DNA replication, ageing, mitochondrial biogenesis) and it is shown herein that SUN4 plays a role in the cell septation process. sun4 delta cells are larger than wild-type and begin a new cell cycle before they have separated from their mother cell. This phenotype is more pronounced in sun4Delta cells also deleted for UTH1. FACS analysis shows apparent polyploidy which disappears when the cell cycle is arrested by mating factor or nocodazole, indicating that cell septation is delayed without modification of the doubling time. Elutriated sun4 delta uth1 delta daughter cells are born larger, and therefore enter S phase sooner than their wild-type counterpart. S phase duration, as well as timing of Clb2 degradation, is normal, but cell septation is delayed. Sun4p/Scw3p was recently described as a cell wall protein (Cappellaro et al., 1998) and, consistent with this notion, electron micrographs of sun4 delta cells show defects in the final steps of cell wall septation. Our data suggest that Sun4p and Uth1p might contribute to the regulated process of cell wall morphogenesis and septation.
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Affiliation(s)
- M Mouassite
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Segalen Bordeaux 2, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
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