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Manzoor Y, Aouida M, Ramadoss R, Moovarkumudalvan B, Ahmed N, Sulaiman AA, Mohanty A, Ali R, Mifsud B, Ramotar D. Loss of the yeast transporter Agp2 upregulates the pleiotropic drug-resistant pump Pdr5 and confers resistance to the protein synthesis inhibitor cycloheximide. PLoS One 2024; 19:e0303747. [PMID: 38776347 PMCID: PMC11111045 DOI: 10.1371/journal.pone.0303747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/30/2024] [Indexed: 05/24/2024] Open
Abstract
The transmembrane protein Agp2, initially shown as a transporter of L-carnitine, mediates the high-affinity transport of polyamines and the anticancer drug bleomycin-A5. Cells lacking Agp2 are hyper-resistant to polyamine and bleomycin-A5. In these earlier studies, we showed that the protein synthesis inhibitor cycloheximide blocked the uptake of bleomycin-A5 into the cells suggesting that the drug uptake system may require de novo synthesis. However, our recent findings demonstrated that cycloheximide, instead, induced rapid degradation of Agp2, and in the absence of Agp2 cells are resistant to cycloheximide. These observations raised the possibility that the degradation of Agp2 may allow the cell to alter its drug resistance network to combat the toxic effects of cycloheximide. In this study, we show that membrane extracts from agp2Δ mutants accentuated several proteins that were differentially expressed in comparison to the parent. Mass spectrometry analysis of the membrane extracts uncovered the pleiotropic drug efflux pump, Pdr5, involved in the efflux of cycloheximide, as a key protein upregulated in the agp2Δ mutant. Moreover, a global gene expression analysis revealed that 322 genes were differentially affected in the agp2Δ mutant versus the parent, including the prominent PDR5 gene and genes required for mitochondrial function. We further show that Agp2 is associated with the upstream region of the PDR5 gene, leading to the hypothesis that cycloheximide resistance displayed by the agp2Δ mutant is due to the derepression of the PDR5 gene.
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Affiliation(s)
- Yusra Manzoor
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Mustapha Aouida
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Ramya Ramadoss
- Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India
| | - Balasubramanian Moovarkumudalvan
- Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to be University), Puducherry, India
- Division of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Nisar Ahmed
- Division of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Abdallah Alhaj Sulaiman
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Ashima Mohanty
- Division of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Reem Ali
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Borbala Mifsud
- Division of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
| | - Dindial Ramotar
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, Qatar
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2
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Chow EWL, Song Y, Wang H, Xu X, Gao J, Wang Y. Genome-wide profiling of piggyBac transposon insertion mutants reveals loss of the F 1F 0 ATPase complex causes fluconazole resistance in Candida glabrata. Mol Microbiol 2024; 121:781-797. [PMID: 38242855 DOI: 10.1111/mmi.15229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/21/2024]
Abstract
Invasive candidiasis caused by non-albicans species has been on the rise, with Candida glabrata emerging as the second most common etiological agent. Candida glabrata possesses an intrinsically lower susceptibility to azoles and an alarming propensity to rapidly develop high-level azole resistance during treatment. In this study, we have developed an efficient piggyBac (PB) transposon-mediated mutagenesis system in C. glabrata to conduct genome-wide genetic screens and applied it to profile genes that contribute to azole resistance. When challenged with the antifungal drug fluconazole, PB insertion into 270 genes led to significant resistance. A large subset of these genes has a role in the mitochondria, including almost all genes encoding the subunits of the F1F0 ATPase complex. We show that deleting ATP3 or ATP22 results in increased azole resistance but does not affect susceptibility to polyenes and echinocandins. The increased azole resistance is due to increased expression of PDR1 that encodes a transcription factor known to promote drug efflux pump expression. Deleting PDR1 in the atp3Δ or atp22Δ mutant resulted in hypersensitivity to fluconazole. Our results shed light on the mechanisms contributing to azole resistance in C. glabrata. This PB transposon-mediated mutagenesis system can significantly facilitate future genome-wide genetic screens.
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Affiliation(s)
- Eve W L Chow
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Yabing Song
- School of Life Sciences, Tsinghua University, Beijing, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Haitao Wang
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Xiaoli Xu
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Jiaxin Gao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yue Wang
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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3
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Knorre DA. Mitochondrial heteroplasmy as a cause of cell-to-cell phenotypic heterogeneity in clonal populations. Front Cell Dev Biol 2023; 11:1276629. [PMID: 37886395 PMCID: PMC10598549 DOI: 10.3389/fcell.2023.1276629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Affiliation(s)
- Dmitry A. Knorre
- Department of Molecular Energetics of Microorganisms, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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4
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Badrane H, Cheng S, Dupont CL, Hao B, Driscoll E, Morder K, Liu G, Newbrough A, Fleres G, Kaul D, Espinoza JL, Clancy CJ, Nguyen MH. Genotypic diversity and unrecognized antifungal resistance among populations of Candida glabrata from positive blood cultures. Nat Commun 2023; 14:5918. [PMID: 37739935 PMCID: PMC10516878 DOI: 10.1038/s41467-023-41509-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 09/07/2023] [Indexed: 09/24/2023] Open
Abstract
The longstanding model is that most bloodstream infections (BSIs) are caused by a single organism. We perform whole genome sequencing of five-to-ten strains from blood culture (BC) bottles in each of ten patients with Candida glabrata BSI. We demonstrate that BCs contain mixed populations of clonal but genetically diverse strains. Genetically distinct strains from two patients exhibit phenotypes that are potentially important during BSIs, including differences in susceptibility to antifungal agents and phagocytosis. In both patients, the clinical microbiology lab recovered a fluconazole-susceptible index strain, but we identify mixed fluconazole-susceptible and -resistant populations. Diversity in drug susceptibility is likely clinically relevant, as fluconazole-resistant strains were subsequently recovered by the clinical laboratory during persistent or relapsing infections. In one patient, unrecognized respiration-deficient small colony variants are fluconazole-resistant and significantly attenuated for virulence during murine candidiasis. Our data suggest a population-based model of C. glabrata genotypic and phenotypic diversity during BSIs.
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Affiliation(s)
| | | | | | - Binghua Hao
- University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Guojun Liu
- University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Drishti Kaul
- J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | | | - Cornelius J Clancy
- University of Pittsburgh, Pittsburgh, PA, USA
- VA Pittsburgh Healthcare System, Pittsburgh, PA, USA
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5
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Zhou X, Yang G, Li C, Yang F, Chang X. Requirement of a putative mitochondrial GTPase, GemA, for azole susceptibility, virulence, and cell wall integrity in Aspergillus fumigatus. Front Microbiol 2022; 13:957857. [PMID: 36016773 PMCID: PMC9396130 DOI: 10.3389/fmicb.2022.957857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/15/2022] [Indexed: 11/13/2022] Open
Abstract
Drug resistance in fungal pathogens is a new challenge in clinical aspergillosis treatment. Mitochondria as dynamic organelles are involved in numerous biological processes in fungi, including drug resistance. However, little is known about the mechanism underlying mitochondrial regulation of the response of fungal pathogens to antifungal drugs. Here, we showed that a putative mitochondrial GTPase, GemA, a yeast Gem1 homolog, is crucial for the azole response and cell wall integrity in the opportunistic pathogen Aspergillus fumigatus. The fluorescence observation showed that GFP-labeled GemA is located in mitochondria, and loss of gemA results in aberrant giant mitochondrial morphology and abnormal mitochondrial membrane potential. Moreover, a ΔgemA mutant attenuates fungal virulence in the Galleria mellonella model of aspergillosis. Furthermore, gemA loss increases resistance to azoles and terbinafine but not to amphotericin B. Of note, RNA-seq combined with RT-qPCR showed that a series of drug efflux pumps were upregulated in the gemA deletion mutant. Deleting mdr1 or inhibiting the expression of drug efflux pumps can partially decrease the resistance to azoles resulting from the gemA mutant, implying that GemA influences azole response by affecting the expression of drug efflux pumps. Importantly, the ΔgemA mutant is susceptible to the cell wall-perturbing reagent CR, but not to CFW, and this defect can be partly rescued by hyperosmotic stress. TEM revealed that the cell wall of ΔgemA was thicker than that of the WT strain, demonstrating that GemA plays a role in cell wall composition and integrity. Collectively, we identified a putative mitochondrial GTPase, GemA, which is critical for hyphal growth, virulence, azole susceptibility, and cell wall integrity and acts by affecting mitochondrial function.
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6
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Knorre DA, Galkina KV, Shirokovskikh T, Banerjee A, Prasad R. Do Multiple Drug Resistance Transporters Interfere with Cell Functioning under Normal Conditions? BIOCHEMISTRY (MOSCOW) 2021; 85:1560-1569. [PMID: 33705294 DOI: 10.1134/s0006297920120081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Eukaryotic cells rely on multiple mechanisms to protect themselves from exogenous toxic compounds. For instance, cells can limit penetration of toxic molecules through the plasma membrane or sequester them within the specialized compartments. Plasma membrane transporters with broad substrate specificity confer multiple drug resistance (MDR) to cells. These transporters efflux toxic compounds at the cost of ATP hydrolysis (ABC-transporters) or proton influx (MFS-transporters). In our review, we discuss the possible costs of having an active drug-efflux system using yeast cells as an example. The pleiotropic drug resistance (PDR) subfamily ABC-transporters are known to constitutively hydrolyze ATP even without any substrate stimulation or transport across the membrane. Besides, some MDR-transporters have flippase activity allowing transport of lipids from inner to outer lipid layer of the plasma membrane. Thus, excessive activity of MDR-transporters can adversely affect plasma membrane properties. Moreover, broad substrate specificity of ABC-transporters also suggests the possibility of unintentional efflux of some natural metabolic intermediates from the cells. Furthermore, in some microorganisms, transport of quorum-sensing factors is mediated by MDR transporters; thus, overexpression of the transporters can also disturb cell-to-cell communications. As a result, under normal conditions, cells keep MDR-transporter genes repressed and activate them only upon exposure to stresses. We speculate that exploiting limitations of the drug-efflux system is a promising strategy to counteract MDR in pathogenic fungi.
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Affiliation(s)
- D A Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia. .,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - K V Galkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - T Shirokovskikh
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A Banerjee
- Amity Institute of Biotechnology and Amity Institute of Integrative Sciences and Health, Amity University Haryana, Amity Education Valley, Gurugram, 122413, India
| | - R Prasad
- Amity Institute of Biotechnology and Amity Institute of Integrative Sciences and Health, Amity University Haryana, Amity Education Valley, Gurugram, 122413, India
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7
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Bhattacharya S, Oliveira NK, Savitt AG, Silva VKA, Krausert RB, Ghebrehiwet B, Fries BC. Low Glucose Mediated Fluconazole Tolerance in Cryptococcus neoformans. J Fungi (Basel) 2021; 7:jof7060489. [PMID: 34207384 PMCID: PMC8233753 DOI: 10.3390/jof7060489] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 01/07/2023] Open
Abstract
Chronic meningoencephalitis is caused by Cryptococcus neoformans and is treated in many parts of the world with fluconazole (FLC) monotherapy, which is associated with treatment failure and poor outcome. In the host, C. neoformans propagates predominantly under low glucose growth conditions. We investigated whether low glucose, mimicked by growing in synthetic media (SM) with 0.05% glucose (SMlowglu), affects FLC-resistance. A > 4-fold increase in FLC tolerance was observed in seven C. neoformans strains when minimum inhibitory concentration (MIC) was determined in SMlowglu compared to MIC in SM with normal (2%) glucose (SMnlglu). In SMlowglu, C. neoformans cells exhibited upregulation of efflux pump genes AFR1 (8.7-fold) and AFR2 (2.5-fold), as well as decreased accumulation (2.6-fold) of Nile Red, an efflux pump substrate. Elevated intracellular ATP levels (3.2-fold and 3.4-fold), as well as decreased mitochondrial reactive oxygen species levels (12.8-fold and 17-fold), were found in the presence and absence of FLC, indicating that low glucose altered mitochondrial function. Fluorescence microscopy revealed that mitochondria of C. neoformans grown in SMlowglu were fragmented, whereas normal glucose promoted a reticular network of mitochondria. Although mitochondrial membrane potential (MMP) was not markedly affected in SMlowglu, it significantly decreased in the presence of FLC (12.5-fold) in SMnlglu, but remained stable in SMlowglu-growing C. neoformans cells. Our data demonstrate that increased FLC tolerance in low glucose-growing C. neoformans is the result of increased efflux pump activities and altered mitochondrial function, which is more preserved in SMlowglu. This mechanism of resistance is different from FLC heteroresistance, which is associated with aneuploidy of chromosome 1 (Chr1).
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Affiliation(s)
- Somanon Bhattacharya
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (S.B.); (V.K.A.S.)
| | - Natalia Kronbauer Oliveira
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (N.K.O.); (A.G.S.); (R.B.K.)
| | - Anne G. Savitt
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (N.K.O.); (A.G.S.); (R.B.K.)
| | - Vanessa K. A. Silva
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (S.B.); (V.K.A.S.)
| | - Rachel B. Krausert
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (N.K.O.); (A.G.S.); (R.B.K.)
| | - Berhane Ghebrehiwet
- Division of Rheumatology, Allergy and Immunology, Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA;
| | - Bettina C. Fries
- Division of Infectious Diseases, Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (S.B.); (V.K.A.S.)
- Department of Microbiology and Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; (N.K.O.); (A.G.S.); (R.B.K.)
- Veterans Administration Medical Center, Northport, NY 11768, USA
- Correspondence:
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8
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Transient Mitochondria Dysfunction Confers Fungal Cross-Resistance against Phagocytic Killing and Fluconazole. mBio 2021; 12:e0112821. [PMID: 34061590 PMCID: PMC8262853 DOI: 10.1128/mbio.01128-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Loss or inactivation of antivirulence genes is an adaptive strategy in pathogen evolution. Candida glabrata is an important opportunistic pathogen related to baker’s yeast, with the ability to both quickly increase its intrinsic high level of azole resistance and persist within phagocytes. During C. glabrata’s evolution as a pathogen, the mitochondrial DNA polymerase CgMip1 has been under positive selection. We show that CgMIP1 deletion not only triggers loss of mitochondrial function and a petite phenotype, but increases C. glabrata’s azole and endoplasmic reticulum (ER) stress resistance and, importantly, its survival in phagocytes. The same phenotype is induced by fluconazole and by exposure to macrophages, conferring a cross-resistance between antifungals and immune cells, and can be found in clinical isolates despite a slow growth of petite strains. This suggests that petite constitutes a bet-hedging strategy of C. glabrata and, potentially, a relevant cause of azole resistance. Mitochondrial function may therefore be considered a potential antivirulence factor.
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9
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Protonophore FCCP provides fitness advantage to PDR-deficient yeast cells. J Bioenerg Biomembr 2020; 52:383-395. [DOI: 10.1007/s10863-020-09849-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 08/06/2020] [Indexed: 01/02/2023]
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10
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Dhar R, Missarova AM, Lehner B, Carey LB. Single cell functional genomics reveals the importance of mitochondria in cell-to-cell phenotypic variation. eLife 2019; 8:38904. [PMID: 30638445 PMCID: PMC6366901 DOI: 10.7554/elife.38904] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/13/2019] [Indexed: 12/12/2022] Open
Abstract
Mutations frequently have outcomes that differ across individuals, even when these individuals are genetically identical and share a common environment. Moreover, individual microbial and mammalian cells can vary substantially in their proliferation rates, stress tolerance, and drug resistance, with important implications for the treatment of infections and cancer. To investigate the causes of cell-to-cell variation in proliferation, we used a high-throughput automated microscopy assay to quantify the impact of deleting >1500 genes in yeast. Mutations affecting mitochondria were particularly variable in their outcome. In both mutant and wild-type cells mitochondrial membrane potential - but not amount - varied substantially across individual cells and predicted cell-to-cell variation in proliferation, mutation outcome, stress tolerance, and resistance to a clinically used anti-fungal drug. These results suggest an important role for cell-to-cell variation in the state of an organelle in single cell phenotypic variation.
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Affiliation(s)
- Riddhiman Dhar
- Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain.,Department of Biotechnology, Indian Institute of Technology, Kharagpur, India
| | - Alsu M Missarova
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Ben Lehner
- Systems Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Lucas B Carey
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
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Mitochondrial Genome Variation Affects Multiple Respiration and Nonrespiration Phenotypes in Saccharomyces cerevisiae. Genetics 2018; 211:773-786. [PMID: 30498022 DOI: 10.1534/genetics.118.301546] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/20/2018] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial genome variation and its effects on phenotypes have been widely analyzed in higher eukaryotes but less so in the model eukaryote Saccharomyces cerevisiae Here, we describe mitochondrial genome variation in 96 diverse S. cerevisiae strains and assess associations between mitochondrial genotype and phenotypes as well as nuclear-mitochondrial epistasis. We associate sensitivity to the ATP synthase inhibitor oligomycin with SNPs in the mitochondrially encoded ATP6 gene. We describe the use of iso-nuclear F1 pairs, the mitochondrial genome equivalent of reciprocal hemizygosity analysis, to identify and analyze mitochondrial genotype-dependent phenotypes. Using iso-nuclear F1 pairs, we analyze the oligomycin phenotype-ATP6 association and find extensive nuclear-mitochondrial epistasis. Similarly, in iso-nuclear F1 pairs, we identify many additional mitochondrial genotype-dependent respiration phenotypes, for which there was no association in the 96 strains, and again find extensive nuclear-mitochondrial epistasis that likely contributes to the lack of association in the 96 strains. Finally, in iso-nuclear F1 pairs, we identify novel mitochondrial genotype-dependent nonrespiration phenotypes: resistance to cycloheximide, ketoconazole, and copper. We discuss potential mechanisms and the implications of mitochondrial genotype and of nuclear-mitochondrial epistasis effects on respiratory and nonrespiratory quantitative traits.
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12
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Identification and Characterization of Key Charged Residues in the Cofilin Protein Involved in Azole Susceptibility, Apoptosis, and Virulence of Aspergillus fumigatus. Antimicrob Agents Chemother 2018; 62:AAC.01659-17. [PMID: 29483117 DOI: 10.1128/aac.01659-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/10/2018] [Indexed: 12/28/2022] Open
Abstract
Through some specific amino acid residues, cofilin, a ubiquitous actin depolymerization factor, can significantly affect mitochondrial function related to drug resistance and apoptosis in Saccharomyces cerevisiae; however, this modulation in a major fungal pathogen, Aspergillus fumigatus, was still unclear. Hereby, it was found, first, that mutations on several charged residues in cofilin to alanine, D19A-R21A, E48A, and K36A, increased the formation of reactive oxygen species and induced apoptosis along with typical hallmarks, including mitochondrial membrane potential depolarization, cytochrome c release, upregulation of metacaspases, and DNA cleavage, in A. fumigatus Two of these mutations (D19A-R21A and K36A) increased acetyl coenzyme A and ATP concentrations by triggering fatty acid β-oxidation. The upregulated acetyl coenzyme A affected the ergosterol biosynthetic pathway, leading to overexpression of cyp51A and -B, while excess ATP fueled ATP-binding cassette transporters. Besides, both of these mutations reduced the susceptibility of A. fumigatus to azole drugs and enhanced the virulence of A. fumigatus in a Galleria mellonella infection model. Taken together, novel and key charged residues in cofilin were identified to be essential modules regulating the mitochondrial function involved in azole susceptibility, apoptosis, and virulence of A. fumigatus.
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13
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Trendeleva TA, Zvyagilskaya RA. Retrograde Signaling as a Mechanism of Yeast Adaptation to Unfavorable Factors. BIOCHEMISTRY (MOSCOW) 2018; 83:98-106. [PMID: 29618296 DOI: 10.1134/s0006297918020025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mitochondria perform many essential functions in eukaryotic cells. Being the main producers of ATP and the site of many catabolic and anabolic reactions, they participate in intracellular signaling, proliferation, aging, and formation of reactive oxygen species. Mitochondrial dysfunction is the cause of many diseases and even cell death. The functioning of mitochondria in vivo is impossible without interaction with other cellular compartments. Mitochondrial retrograde signaling is a signaling pathway connecting mitochondria and the nucleus. The major signal transducers in the yeast retrograde response are Rtg1p, Rtg2p, and Rtg3p proteins, as well as four additional negative regulatory factors - Mks1p, Lst8p, and two 14-3-3 proteins (Bmh1/2p). In this review, we analyze current information on the retrograde signaling in yeast that is regarded as a stress or homeostatic response mechanism to changes in various metabolic and biosynthetic activities that occur upon mitochondrial dysfunction. We also discuss relations between retrograde signaling and other signaling pathways in the cell.
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Affiliation(s)
- T A Trendeleva
- Fundamentals of Biotechnology Federal Research Centre, Russian Academy of Sciences, Moscow, 119071, Russia;.
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14
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Khakhina S, Simonicova L, Moye-Rowley WS. Positive autoregulation and repression of transactivation are key regulatory features of the Candida glabrata Pdr1 transcription factor. Mol Microbiol 2018; 107:747-764. [PMID: 29363861 DOI: 10.1111/mmi.13913] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/15/2018] [Accepted: 01/19/2018] [Indexed: 12/23/2022]
Abstract
Resistance to azole drugs, the major clinical antifungal compounds, is most commonly due to gain-of-function (GOF) substitution mutations in a gene called PDR1 in the fungal pathogen Candida glabrata. PDR1 encodes a zinc cluster-containing transcription factor. GOF forms of Pdr1 drive high level expression of downstream target gene expression with accompanying azole resistance. PDR1 has two homologous genes in Saccharomyces cerevisiae, called ScPDR1 and ScPDR3. This study provides evidence that the PDR1 gene in C. glabrata represents a blend of the properties found in the two S. cerevisiae genes. We demonstrated that GOF Pdr1 derivatives are overproduced at the protein level and less stable than the wild-type protein. Overproduction of wild-type Pdr1 increased target gene expression but to a lesser extent than GOF derivatives. Site-directed mutagenesis of Pdr1 binding sites in the PDR1 promoter provided clear demonstration that autoregulation of PDR1 is required for its normal function. An internal deletion mutant of Pdr1 lacking its central regulatory domain behaved as a hyperactive transcription factor that was lethal unless conditionally expressed. A full understanding of the regulation of Pdr1 will provide a new avenue of interfering with azole resistance in C. glabrata.
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Affiliation(s)
- Svetlana Khakhina
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Lucia Simonicova
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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15
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Verma S, Shakya VPS, Idnurm A. Exploring and exploiting the connection between mitochondria and the virulence of human pathogenic fungi. Virulence 2018; 9:426-446. [PMID: 29261004 PMCID: PMC5955198 DOI: 10.1080/21505594.2017.1414133] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are best known for their role in the production of ATP; however, recent research implicates other mitochondrial functions in the virulence of human pathogenic fungi. Inhibitors of mitochondrial succinate dehydrogenase or the electron transport chain are successfully used to combat plant pathogenic fungi, but similar inhibition of mitochondrial functions has not been pursued for applications in medical mycology. Advances in understanding mitochondrial function relevant to human pathogenic fungi are in four major directions: 1) the role of mitochondrial morphology in virulence, 2) mitochondrial genetics, with a focus on mitochondrial DNA recombination and mitochondrial inheritance 3) the role of mitochondria in drug resistance, and 4) the interaction of mitochondria with other organelles. Collectively, despite the similarities in mitochondrial functions between fungi and animals, this organelle is currently an under-explored potential target to treat medical mycoses. Future research could define and then exploit those mitochondrial components best suited as drug targets.
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Affiliation(s)
- Surbhi Verma
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Viplendra P. S. Shakya
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Alexander Idnurm
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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16
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Regulation of Mitochondrial, Cellular, and Organismal Functions by TSPO. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:103-136. [PMID: 29413517 DOI: 10.1016/bs.apha.2017.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In 1999, the enigma of the 18kDa mitochondrial translocator protein (TSPO), also known as the peripheral-type benzodiazepine receptor, was the seeming disparity of the many functions attributed to TSPO, ranging from the potential of TSPO acting as a housekeeping gene at molecular biological levels to adaptations to stress, and even involvement in higher emotional and cognitive functioning, such as anxiety and depression. In the years since then, knowledge regarding the many functions modulated by TSPO has expanded, and understanding has deepened. In addition, new functions could be firmly associated with TSPO, such as regulation of programmed cell death and modulation of gene expression. Interestingly, control by the mitochondrial TSPO over both of these life and death functions appears to include Ca++ homeostasis, generation of reactive oxygen species (ROS), and ATP production. Other mitochondrial functions under TSPO control are considered to be steroidogenesis and tetrapyrrole metabolism. As TSPO effects on gene expression and on programmed cell death can be related to the wide range of functions that can be associated with TSPO, several of these five elements of Ca++, ROS, ATP, steroids, and tetrapyrroles may indeed form the basis of TSPO's capability to operate as a multifunctional housekeeping gene to maintain homeostasis of the cell and of the whole multicellular organism.
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17
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Toth Hervay N, Konecna A, Balazfyova Z, Svrbicka A, Gbelska Y. Insight into the Kluyveromyces lactis Pdr1p regulon. Can J Microbiol 2016; 62:918-931. [PMID: 27556366 DOI: 10.1139/cjm-2016-0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The overexpression of efflux pumps is an important mechanism leading to the development of multidrug resistance phenomenon. The transcription factor KlPdr1p, belonging to the Zn2Cys6 family, is a central regulator of efflux pump expression in Kluyveromyces lactis. To better understand how KlPDR1-mediated drug resistance is achieved in K. lactis, we used DNA microarrays to identify genes whose expression was affected by deletion or overexpression of the KlPDR1 gene. Eighty-nine targets of the KlPDR1 were identified. From those the transcription of 16 genes was induced in the transformant overexpressing KlPDR1* and simultaneously repressed in the Klpdr1Δ deletion mutant. Almost all of these genes contain putative binding motifs for the AP-1-like transcription factors in their promoters. Furthermore, we studied the possible interplay between KlPdr1p and KlYap1p transcription factors. Our results show that KlYap1p does not significantly contribute to the regulation of KlPDR1 gene expression in the presence of azoles. However, KlPDR1 expression markedly increased in the presence of hydrogen peroxide and hinged upon the presence of KlYap1p. Our results show that although both KlPdr1p and KlYap1p transcription factors are involved in the control of K. lactis multidrug resistance, further studies will be needed to determine their interplay.
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Affiliation(s)
- Nora Toth Hervay
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Konecna
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Zuzana Balazfyova
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Alexandra Svrbicka
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
| | - Yvetta Gbelska
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic.,Comenius University in Bratislava, Faculty of Natural Sciences, Department of Microbiology and Virology, Ilkovicova 6, Mlynska dolina, 842 15 Bratislava, Slovak Republic
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18
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Day M. Yeast petites and small colony variants: for everything there is a season. ADVANCES IN APPLIED MICROBIOLOGY 2016; 85:1-41. [PMID: 23942147 DOI: 10.1016/b978-0-12-407672-3.00001-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The yeast petite mutant was first found in the yeast Saccharomyces cerevisiae. The colony is small because of a block in the aerobic respiratory chain pathway, which generates ATP. The petite yeasts are thus unable to grow on nonfermentable carbon sources (such as glycerol or ethanol), and form small anaerobic-sized colonies when grown in the presence of fermentable carbon sources (such as glucose). The petite phenotype results from mutations in the mitochondrial genome, loss of mitochondria, or mutations in the host cell genome. The latter mutations affect nuclear-encoded genes involved in oxidative phosphorylation and these mutants are termed neutral petites. They all produce wild-type progeny when crossed with a wild-type strain. The staphylococcal small colony variant (SCV) is a slow-growing mutant that typically exhibits the loss of many phenotypic characteristics and pathogenic traits. SCVs are mostly small, nonpigmented, and nonhaemolytic. Their small size is often due to an inability to synthesize electron transport chain components and so cannot generate ATP by oxidative phosphorylation. Evidence suggests that they are responsible for persistent and/or recurrent infections. This chapter compares the physiological and genetic basis of the petite mutants and SCVs. The review focuses principally on two representatives, the eukaryote S. cerevisiae and the prokaryote Staphylococcus aureus. There is, clearly, commonality in the physiological response. Interestingly, the similarity, based on their physiological states, has not been commented on previously. The finding of an overlapping physiological response that occurs across a taxonomic divide is novel.
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Affiliation(s)
- Martin Day
- School of Biosciences, Cardiff University, Cardiff, United Kingdom.
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19
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Mitochondrial Retrograde Signaling: Triggers, Pathways, and Outcomes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:482582. [PMID: 26583058 PMCID: PMC4637108 DOI: 10.1155/2015/482582] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/08/2015] [Accepted: 05/13/2015] [Indexed: 12/22/2022]
Abstract
Mitochondria are essential organelles for eukaryotic homeostasis. Although these organelles possess their own DNA, the vast majority (>99%) of mitochondrial proteins are encoded in the nucleus. This situation makes systems that allow the communication between mitochondria and the nucleus a requirement not only to coordinate mitochondrial protein synthesis during biogenesis but also to communicate eventual mitochondrial malfunctions, triggering compensatory responses in the nucleus. Mitochondria-to-nucleus retrograde signaling has been described in various organisms, albeit with differences in effector pathways, molecules, and outcomes, as discussed in this review.
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Humbert A, Bovier E, Sellem CH, Sainsard-Chanet A. Deletion of the MED13 and CDK8 subunits of the Mediator improves the phenotype of a long-lived respiratory deficient mutant of Podospora anserina. Fungal Genet Biol 2015; 82:228-37. [PMID: 26231682 DOI: 10.1016/j.fgb.2015.07.010] [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: 06/05/2015] [Revised: 07/27/2015] [Accepted: 07/28/2015] [Indexed: 01/18/2023]
Abstract
In Podospora anserina, the loss of function of the cytochrome segment of the mitochondrial respiratory chain is viable. This is due to the presence in this organism, as in most filamentous fungi, of an alternative respiratory oxidase (AOX) that provides a bypass to the cytochrome pathway. However mutants lacking a functional cytochrome pathway present multiple phenotypes including poorly colored thin mycelium and slow growth. In a large genetic screen based on the improvement of these phenotypes, we isolated a large number of independent suppressor mutations. Most of them led to the constitutive overexpression of the aox gene. In this study, we characterize a new suppressor mutation that does not affect the production of AOX. It is a loss-of-function mutation in the gene encoding the MED13 subunit of the kinase module of the Mediator complex. Inactivation of the cdk8 gene encoding another subunit of the same module also results in partial suppression of a cytochrome-deficient mutant. Analysis of strains lacking the MED13 or CDK8 subunits points to the importance of these subunits as regulators involved in diverse physiological processes such as growth, longevity and sexual development. Interestingly, transcriptional analyses indicate that in P. anserina, loss of the respiratory cytochrome pathway results in the up-regulation of glycolysis-related genes revealing a new type of retrograde regulation. The loss of MED13 augments the up-regulation of some of these genes.
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Affiliation(s)
- Adeline Humbert
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Elodie Bovier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Carole H Sellem
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Annie Sainsard-Chanet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France.
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21
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Nishida-Aoki N, Mori H, Kuroda K, Ueda M. Activation of the mitochondrial signaling pathway in response to organic solvent stress in yeast. Curr Genet 2014; 61:153-64. [DOI: 10.1007/s00294-014-0463-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
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22
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Dzialo MC, Travaglini KJ, Shen S, Roy K, Chanfreau GF, Loo JA, Clarke SG. Translational roles of elongation factor 2 protein lysine methylation. J Biol Chem 2014; 289:30511-30524. [PMID: 25231983 DOI: 10.1074/jbc.m114.605527] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Methylation of various components of the translational machinery has been shown to globally affect protein synthesis. Little is currently known about the role of lysine methylation on elongation factors. Here we show that in Saccharomyces cerevisiae, the product of the EFM3/YJR129C gene is responsible for the trimethylation of lysine 509 on elongation factor 2. Deletion of EFM3 or of the previously described EFM2 increases sensitivity to antibiotics that target translation and decreases translational fidelity. Furthermore, the amino acid sequences of Efm3 and Efm2, as well as their respective methylation sites on EF2, are conserved in other eukaryotes. These results suggest the importance of lysine methylation modification of EF2 in fine tuning the translational apparatus.
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Affiliation(s)
- Maria C Dzialo
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Kyle J Travaglini
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Sean Shen
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Kevin Roy
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Joseph A Loo
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095; Department of Biological Chemistry and UCLA/Department of Energy Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095.
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23
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Proteomic analysis of the soluble proteomes of miltefosine-sensitive and -resistant Leishmania infantum chagasi isolates obtained from Brazilian patients with different treatment outcomes. J Proteomics 2014; 108:198-208. [DOI: 10.1016/j.jprot.2014.05.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 01/12/2023]
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24
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Paul S, Moye-Rowley WS. Multidrug resistance in fungi: regulation of transporter-encoding gene expression. Front Physiol 2014; 5:143. [PMID: 24795641 PMCID: PMC3997011 DOI: 10.3389/fphys.2014.00143] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 03/25/2014] [Indexed: 11/24/2022] Open
Abstract
A critical risk to the continued success of antifungal chemotherapy is the acquisition of resistance; a risk exacerbated by the few classes of effective antifungal drugs. Predictably, as the use of these drugs increases in the clinic, more resistant organisms can be isolated from patients. A particularly problematic form of drug resistance that routinely emerges in the major fungal pathogens is known as multidrug resistance. Multidrug resistance refers to the simultaneous acquisition of tolerance to a range of drugs via a limited or even single genetic change. This review will focus on recent progress in understanding pathways of multidrug resistance in fungi including those of most medical relevance. Analyses of multidrug resistance in Saccharomyces cerevisiae have provided the most detailed outline of multidrug resistance in a eukaryotic microorganism. Multidrug resistant isolates of S. cerevisiae typically result from changes in the activity of a pair of related transcription factors that in turn elicit overproduction of several target genes. Chief among these is the ATP-binding cassette (ABC)-encoding gene PDR5. Interestingly, in the medically important Candida species, very similar pathways are involved in acquisition of multidrug resistance. In both C. albicans and C. glabrata, changes in the activity of transcriptional activator proteins elicits overproduction of a protein closely related to S. cerevisiae Pdr5 called Cdr1. The major filamentous fungal pathogen, Aspergillus fumigatus, was previously thought to acquire resistance to azole compounds (the principal antifungal drug class) via alterations in the azole drug target-encoding gene cyp51A. More recent data indicate that pathways in addition to changes in the cyp51A gene are important determinants in A. fumigatus azole resistance. We will discuss findings that suggest azole resistance in A. fumigatus and Candida species may share more mechanistic similarities than previously thought.
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Affiliation(s)
- Sanjoy Paul
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa Iowa City, IA, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa Iowa City, IA, USA
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25
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Li J, Pandeya D, Jo YD, Liu WY, Kang BC. Reduced activity of ATP synthase in mitochondria causes cytoplasmic male sterility in chili pepper. PLANTA 2013; 237:1097-109. [PMID: 23274393 DOI: 10.1007/s00425-012-1824-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 11/22/2012] [Indexed: 05/05/2023]
Abstract
Cytoplasmic male sterility (CMS) is a maternally inherited trait characterized by the inability to produce functional pollen. The CMS-associated protein Orf507 (reported as Orf456 in previous researches) was previously identified as a candidate gene for mediating male sterility in pepper. Here, we performed yeast two-hybrid analysis to screen for interacting proteins, and found that the ATP synthase 6 kDa subunit containing a mitochondrial signal peptide (MtATP6) specifically interacted with Orf507. In addition, the two proteins were found to be interacted in vivo using bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP) assays. Further functional characterization of Orf507 revealed that the encoded protein is toxic to bacterial cells. Analysis of tissue-specific expression of ATP synthase 6 kDa showed that the transcription level was much lower in anthers of the CMS line than in their wild type counterparts. In CMS plants, ATP synthase activity and content were reduced by more than half compared to that of the normal plants. Taken together, it can be concluded that reduced ATP synthase activity and ATP content might have affected pollen development in CMS plants. Here, we hypothesize that Orf507 might cause MtATP6 to be nonfunctional by changing the latter's conformation or producing an inhibitor that prevents the normal functioning of MtATP6. Thus, further functional analysis of mitochondrial Orf507 will provide insights into the mechanisms underlying CMS in plants.
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Affiliation(s)
- Jinjie Li
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agricultural Sciences, Seoul National University, Seoul, Republic of Korea
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26
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Singh A, Yadav V, Prasad R. Comparative lipidomics in clinical isolates of Candida albicans reveal crosstalk between mitochondria, cell wall integrity and azole resistance. PLoS One 2012; 7:e39812. [PMID: 22761908 PMCID: PMC3384591 DOI: 10.1371/journal.pone.0039812] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 05/26/2012] [Indexed: 11/19/2022] Open
Abstract
Prolonged usage of antifungal azoles which target enzymes involved in lipid biosynthesis invariably leads to the development of multi-drug resistance (MDR) in Candida albicans. We had earlier shown that membrane lipids and their fluidity are closely linked to the MDR phenomenon. In one of our recent studies involving comparative lipidomics between azole susceptible (AS) and azole resistant (AR) matched pair clinical isolates of C. albicans, we could not see consistent differences in the lipid profiles of AS and AR strains because they came from different patients and so in this study, we have used genetically related variant recovered from the same patient collected over a period of 2-years. During this time, the levels of fluconazole (FLC) resistance of the strain increased by over 200-fold. By comparing the lipid profiles of select isolates, we were able to observe gradual and statistically significant changes in several lipid classes, particularly in plasma membrane microdomain specific lipids such as mannosylinositolphosphorylceramides and ergosterol, and in a mitochondrial specific phosphoglyceride, phosphatidyl glycerol. Superimposed with these quantitative and qualitative changes in the lipid profiles, were simultaneous changes at the molecular lipid species levels which again coincided with the development of resistance to FLC. Reverse transcriptase-PCR of the key genes of the lipid metabolism validated lipidomic picture. Taken together, this study illustrates how the gradual corrective changes in Candida lipidome correspond to the development of FLC tolerance. Our study also shows a first instance of the mitochondrial membrane dysfunction and defective cell wall (CW) in clinical AR isolates of C. albicans, and provides evidence of a cross-talk between mitochondrial lipid homeostasis, CW integrity and azole tolerance.
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Affiliation(s)
- Ashutosh Singh
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Vipin Yadav
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Rajendra Prasad
- Membrane Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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27
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Discovery of factors linked to antimony resistance in Leishmania panamensis through differential proteome analysis. Mol Biochem Parasitol 2012; 183:166-76. [PMID: 22449941 DOI: 10.1016/j.molbiopara.2012.03.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 12/19/2022]
Abstract
The rate of treatment failure to antileishmanial chemotherapy in Latin America is up to 64%. Parasite drug resistance contributes to an unknown proportion of treatment failures. Identification of clinically relevant molecular mechanisms responsible for parasite drug resistance is critical to the conservation of available drugs and to the discovery of novel targets to reverse the resistant phenotype. We conducted comparative proteomic-based analysis of Leishmania (Viannia) panamensis lines selected in vitro for resistance to trivalent antimony (Sb(III)) to identify factors associated with antimony resistance. Using 2-dimensional gel electrophoresis, two distinct sub-proteomes (soluble in NP-40/urea and Triton X-114, respectively) of promastigotes of WT and Sb(III)-resistant lines were generated. Overall, 9 differentially expressed putative Sb-resistance factors were detected and identified by mass spectrometry. These constituted two major groups: (a) proteins involved in general stress responses and (b) proteins with highly specific metabolic and transport functions, potentially directly contributing to the Sb-resistance mechanism. Notably, the sulfur amino acid-metabolizing enzymes S-adenosylmethionine synthetase (SAMS) and S-adenosylhomocysteine hydrolase (SAHH) were over-expressed in Sb(III)-resistant lines and Sb(III)-resistant clinical isolates. These enzymes play a central role in the upstream synthesis of precursors of trypanothione, a key molecule involved in Sb-resistance in Leishmania parasites, and suggest involvement of epigenetic regulation in response to drug exposure. These data re-enforce the importance of thiol metabolism in Leishmania Sb resistance, reveal previously unrecognized steps in the mechanism(s) of Sb tolerance, and suggest a cross-talk between drug resistance, metabolism and virulence.
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28
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Jones AWE, Yao Z, Vicencio JM, Karkucinska-Wieckowska A, Szabadkai G. PGC-1 family coactivators and cell fate: roles in cancer, neurodegeneration, cardiovascular disease and retrograde mitochondria-nucleus signalling. Mitochondrion 2011; 12:86-99. [PMID: 21983689 DOI: 10.1016/j.mito.2011.09.009] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 09/08/2011] [Accepted: 09/16/2011] [Indexed: 12/29/2022]
Abstract
Over the past two decades, a complex nuclear transcriptional machinery controlling mitochondrial biogenesis and function has been described. Central to this network are the PGC-1 family coactivators, characterised as master regulators of mitochondrial biogenesis. Recent literature has identified a broader role for PGC-1 coactivators in both cell death and cellular adaptation under conditions of stress, here reviewed in the context of the pathology associated with cancer, neurodegeneration and cardiovascular disease. Moreover, we propose that these studies also imply a novel conceptual framework on the general role of mitochondrial dysfunction in disease. It is now well established that the complex nuclear transcriptional control of mitochondrial biogenesis allows for adaptation of mitochondrial mass and function to environmental conditions. On the other hand, it has also been suggested that mitochondria alter their function according to prevailing cellular energetic requirements and thus function as sensors that generate signals to adjust fundamental cellular processes through a retrograde mitochondria-nucleus signalling pathway. Therefore, altered mitochondrial function can affect cell fate not only directly by modifying cellular energy levels or redox state, but also indirectly, by altering nuclear transcriptional patterns. The current literature on such retrograde signalling in both yeast and mammalian cells is thus reviewed, with an outlook on its potential contribution to disease through the regulation of PGC-1 family coactivators. We propose that further investigation of these pathways will lead to the identification of novel pharmacological targets and treatment strategies to combat disease.
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Affiliation(s)
- Aleck W E Jones
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, UK
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29
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Mitochondria and fungal pathogenesis: drug tolerance, virulence, and potential for antifungal therapy. EUKARYOTIC CELL 2011; 10:1376-83. [PMID: 21926328 DOI: 10.1128/ec.05184-11] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recently, mitochondria have been identified as important contributors to the virulence and drug tolerance of human fungal pathogens. In different scenarios, either hypo- or hypervirulence can result from changes in mitochondrial function. Similarly, specific mitochondrial mutations lead to either sensitivity or resistance to antifungal drugs. Here, we provide a synthesis of this emerging field, proposing that mitochondrial function in membrane lipid homeostasis is the common denominator underlying the observed effects of mitochondria in drug tolerance (both sensitivity and resistance). We discuss how the contrasting effects of mitochondrial dysfunction on fungal drug tolerance and virulence could be explained and the potential for targeting mitochondrial factors for future antifungal drug development.
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30
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Dunn CD. Running on empty: does mitochondrial DNA mutation limit replicative lifespan in yeast?: Mutations that increase the division rate of cells lacking mitochondrial DNA also extend replicative lifespan in Saccharomyces cerevisiae. Bioessays 2011; 33:742-8. [PMID: 21826691 DOI: 10.1002/bies.201100050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mitochondrial DNA (mtDNA) mutations escalate with increasing age in higher organisms. However, it has so far been difficult to experimentally determine whether mtDNA mutation merely correlates with age or directly limits lifespan. A recent study shows that budding yeast can also lose functional mtDNA late in life. Interestingly, independent studies of replicative lifespan (RLS) and of mtDNA-deficient cells show that the same mutations can increase both RLS and the division rate of yeast lacking the mitochondrial genome. These exciting, parallel findings imply a potential causal relationship between mtDNA mutation and replicative senescence. Furthermore, these results suggest more efficient methods for discovering genes that determine lifespan.
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Affiliation(s)
- Cory D Dunn
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey.
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31
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Kochmak SA, Knorre DA, Sokolov SS, Severin FF. Physiological scenarios of programmed loss of mitochondrial DNA function and death of yeast. BIOCHEMISTRY (MOSCOW) 2011; 76:167-71. [DOI: 10.1134/s0006297911020015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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van Leeuwen JS, Orij R, Luttik MAH, Smits GJ, Vermeulen NPE, Vos JC. Subunits Rip1p and Cox9p of the respiratory chain contribute to diclofenac-induced mitochondrial dysfunction. Microbiology (Reading) 2011; 157:685-694. [DOI: 10.1099/mic.0.044578-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The widely used drug diclofenac can cause serious heart, liver and kidney injury, which may be related to its ability to cause mitochondrial dysfunction. Using Saccharomyces cerevisiae as a model system, we studied the mechanisms of diclofenac toxicity and the role of mitochondria therein. We found that diclofenac reduced cell growth and viability and increased levels of reactive oxygen species (ROS). Strains increasingly relying on respiration for their energy production showed enhanced sensitivity to diclofenac. Furthermore, oxygen consumption was inhibited by diclofenac, suggesting that the drug inhibits respiration. To identify the site of respiratory inhibition, we investigated the effects of deletion of respiratory chain subunits on diclofenac toxicity. Whereas deletion of most subunits had no effect, loss of either Rip1p of complex III or Cox9p of complex IV resulted in enhanced resistance to diclofenac. In these deletion strains, diclofenac did not increase ROS formation as severely as in the wild-type. Our data are consistent with a mechanism of toxicity in which diclofenac inhibits respiration by interfering with Rip1p and Cox9p in the respiratory chain, resulting in ROS production that causes cell death.
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Affiliation(s)
- Jolanda S. van Leeuwen
- LACDR, Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Rick Orij
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marijke A. H. Luttik
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Gertien J. Smits
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Nico P. E. Vermeulen
- LACDR, Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - J. Chris Vos
- LACDR, Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
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Effects of mancozeb and other dithiocarbamate fungicides on Saccharomyces cerevisiae: the role of mitochondrial petite mutants in dithiocarbamate tolerance. Folia Microbiol (Praha) 2011; 55:593-7. [DOI: 10.1007/s12223-010-0095-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 05/27/2010] [Indexed: 10/18/2022]
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Regulation of the CgPdr1 transcription factor from the pathogen Candida glabrata. EUKARYOTIC CELL 2010; 10:187-97. [PMID: 21131438 DOI: 10.1128/ec.00277-10] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Candida glabrata is an opportunistic human pathogen that is increasingly associated with candidemia, owing in part to the intrinsic and acquired high tolerance the organism exhibits for the important clinical antifungal drug fluconazole. This elevated fluconazole resistance often develops through gain-of-function mutations in the zinc cluster-containing transcriptional regulator C. glabrata Pdr1 (CgPdr1). CgPdr1 induces the expression of an ATP-binding cassette (ABC) transporter-encoding gene, CgCDR1. Saccharomyces cerevisiae has two CgPdr1 homologues called ScPdr1 and ScPdr3. These factors control the expression of an ABC transporter-encoding gene called ScPDR5, which encodes a homologue of CgCDR1. Loss of the mitochondrial genome (ρ(0) cell) or overexpression of the mitochondrial enzyme ScPsd1 induces ScPDR5 expression in a strictly ScPdr3-dependent fashion. ScPdr3 requires the presence of a transcriptional Mediator subunit called Gal11 (Med15) to fully induce ScPDR5 transcription in response to ρ(0) signaling. ScPdr1 does not respond to either ρ(0) signals or ScPsd1 overproduction. In this study, we employed transcriptional fusions between CgPdr1 target promoters, like CgCDR1, to demonstrate that CgPdr1 stimulates gene expression via binding to elements called pleiotropic drug response elements (PDREs). Deletion mapping and electrophoretic mobility shift assays demonstrated that a single PDRE in the CgCDR1 promoter was capable of supporting ρ(0)-induced gene expression. Removal of one of the two ScGal11 homologues from C. glabrata caused a major defect in drug-induced expression of CgCDR1 but had a quantitatively minor effect on ρ(0)-stimulated transcription. These data demonstrate that CgPdr1 appears to combine features of ScPdr1 and ScPdr3 to produce a transcription factor with chimeric regulatory properties.
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35
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Shahi P, Gulshan K, Näär AM, Moye-Rowley WS. Differential roles of transcriptional mediator subunits in regulation of multidrug resistance gene expression in Saccharomyces cerevisiae. Mol Biol Cell 2010; 21:2469-82. [PMID: 20505076 PMCID: PMC2903675 DOI: 10.1091/mbc.e09-10-0899] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Med12 is a transcriptional Mediator subunit most typically associated with negative control of gene expression. Here Med12 is demonstrated to serve as a positive regulator required for activation of multidrug resistance gene expression in yeast cells lacking their mitochondrial genome. The multiprotein transcriptional Mediator complex provides a key link between RNA polymerase II and upstream transcriptional activator proteins. Previous work has established that the multidrug resistance transcription factors Pdr1 and Pdr3 interact with the Mediator component Med15/Gal11 to drive normal levels of expression of the ATP-binding cassette transporter-encoding gene PDR5 in Saccharomyces cerevisiae. PDR5 transcription is induced upon loss of the mitochondrial genome (ρ0 cells) and here we provide evidence that this ρ0 induction is Med15 independent. A search through other known Mediator components determined that Med12/Srb8, a member of the CDK8 Mediator submodule, is required for ρ0 activation of PDR5 transcription. The CDK8 submodule contains the cyclin C homologue (CycC/Srb11), cyclin-dependent kinase Cdk8/Srb10, and the large Med13/Srb9 protein. Loss of these other proteins did not lead to the same block in PDR5 induction. Chromatin immunoprecipitation analyses demonstrated that Med15 is associated with the PDR5 promoter in both ρ+ and ρ0, whereas Med12 recruitment to this target promoter is highly responsive to loss of the mitochondrial genome. Coimmunoprecipitation experiments revealed that association of Pdr3 with Med12 can only be detected in ρ0 cells. These experiments uncover the unique importance of Med12 in activated transcription of PDR5 seen in ρ0 cells.
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Affiliation(s)
- Puja Shahi
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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36
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Gulshan K, Shahi P, Moye-Rowley WS. Compartment-specific synthesis of phosphatidylethanolamine is required for normal heavy metal resistance. Mol Biol Cell 2009; 21:443-55. [PMID: 20016005 PMCID: PMC2814789 DOI: 10.1091/mbc.e09-06-0519] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The enzyme Psd2 catalyzes endosomal synthesis of the phospholipid PE. While this pool of PE represents a minority of total cellular PE, function of Psd2 is required for normal activity of the vacuolar ABC transporter Ycf1. Psd2 controls vacuolar PE levels by acting at the level of the endosome. Control of lipid composition of membranes is crucial to ensure normal cellular functions. Saccharomyces cerevisiae has two different phosphatidylserine decarboxylase enzymes (Psd1 and Psd2) that catalyze formation of phosphatidylethanolamine. The mitochondrial Psd1 provides roughly 70% of the phosphatidylethanolamine (PE) biosynthesis in the cell with Psd2 carrying out the remainder. Here, we demonstrate that loss of Psd2 causes cells to acquire sensitivity to cadmium even though Psd1 remains intact. This cadmium sensitivity results from loss of normal activity of a vacuolar ATP-binding cassette transporter protein called Ycf1. Measurement of phospholipid levels indicates that loss of Psd2 causes a specific reduction in vacuolar membrane PE levels, whereas total PE levels are not significantly affected. The presence of a phosphatidylinositol transfer protein called Pdr17 is required for Psd2 function and normal cadmium tolerance. We demonstrate that Pdr17 and Psd2 form a complex in vivo that seems essential for maintenance of vacuolar PE levels. Finally, we refine the localization of Psd2 to the endosome arguing that this enzyme controls vacuolar membrane phospholipid content by regulating phospholipids in compartments that will eventually give rise to the vacuole. Disturbance of this regulation of intracellular phospholipid balance leads to selective loss of membrane protein function in the vacuole.
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Affiliation(s)
- Kailash Gulshan
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
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37
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Veatch JR, McMurray MA, Nelson ZW, Gottschling DE. Mitochondrial dysfunction leads to nuclear genome instability via an iron-sulfur cluster defect. Cell 2009; 137:1247-58. [PMID: 19563757 DOI: 10.1016/j.cell.2009.04.014] [Citation(s) in RCA: 318] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Revised: 01/30/2009] [Accepted: 04/01/2009] [Indexed: 11/19/2022]
Abstract
Mutations and deletions in the mitochondrial genome (mtDNA), as well as instability of the nuclear genome, are involved in multiple human diseases. Here, we report that in Saccharomyces cerevisiae, loss of mtDNA leads to nuclear genome instability, through a process of cell-cycle arrest and selection we define as a cellular crisis. This crisis is not mediated by the absence of respiration, but instead correlates with a reduction in the mitochondrial membrane potential. Analysis of cells undergoing this crisis identified a defect in iron-sulfur cluster (ISC) biogenesis, which requires normal mitochondrial function. We found that downregulation of nonmitochondrial ISC protein biogenesis was sufficient to cause increased genomic instability in cells with intact mitochondrial function. These results suggest mitochondrial dysfunction stimulates nuclear genome instability by inhibiting the production of ISC-containing protein(s), which are required for maintenance of nuclear genome integrity. For a video summary of this article, see the PaperFlick file available with the online Supplemental Data.
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Affiliation(s)
- Joshua R Veatch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA 98109, USA
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38
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Woo DK, Poyton RO. The absence of a mitochondrial genome in rho0 yeast cells extends lifespan independently of retrograde regulation. Exp Gerontol 2009; 44:390-7. [PMID: 19285548 DOI: 10.1016/j.exger.2009.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 02/26/2009] [Accepted: 03/03/2009] [Indexed: 10/21/2022]
Abstract
The absence of mtDNA in rho0 yeast cells affects both respiration and mitochondrial-nuclear communication (e.g., retrograde regulation, intergenomic signaling, or pleiotropic drug resistance). Previously, it has been reported that some rho0 strains have increased replicative lifespans, attributable to the lack of respiration and retrograde regulation. Here, we have been able to confirm that rho0 cells exhibit increased replicative lifespans but have found that this is not associated with the lack of respiration or reduced oxidative stress but instead, is related to the lack of mtDNA per se in rho0 cells. Also, we find no correlation between the strength of retrograde regulation and lifespan. Furthermore, we find that pdr3- or rtg2- mutations are not responsible for lifespan extension in rho0 cells, ruling out a specific role for PDR3-pleiotropic drug resistance or RGT2-retrograde regulation pathways in the extended lifespans of rho0 cells. Surprisingly, Rtg3p, which acts downstream of Rtg2p, is required for lifespan increase in rho0 cells. Together, these findings indicate that the loss of mtDNA per se and not the lack of respiration lead to extended longevity in rho0 cells. They also suggest that Rtg3p, acting independently of retrograde regulation, mediates this effect, possibly via intergenomic signaling.
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Affiliation(s)
- Dong Kyun Woo
- The Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
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39
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Shahi P, Moye-Rowley WS. Coordinate control of lipid composition and drug transport activities is required for normal multidrug resistance in fungi. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:852-9. [PMID: 19150512 DOI: 10.1016/j.bbapap.2008.12.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/12/2008] [Accepted: 12/15/2008] [Indexed: 10/21/2022]
Abstract
Pathogenic fungi present a special problem in the clinic as the range of drugs that can be used to treat these types of infections is limited. This situation is further complicated by the presence of robust inducible gene networks encoding different proteins that confer tolerance to many available antifungal drugs. The transcriptional control of these multidrug resistance systems in several key fungi will be discussed. Experiments in the non-pathogenic Saccharomyces cerevisiae have provided much of our current understanding of the molecular framework on which fungal multidrug resistance is built. More recent studies on the important pathogenic Candida species, Candida albicans and Candida glabrata, have provided new insights into the organization of the multidrug resistance systems in these organisms. We will compare the circuitry of multidrug resistance networks in these three organisms and suggest that, in addition to the well-accepted drug efflux activities, the regulation of membrane composition by multidrug resistance proteins provides an important contribution to the resistant phenotypes observed.
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Affiliation(s)
- Puja Shahi
- Department of Molecular Physiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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40
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Evidence for the bifunctional nature of mitochondrial phosphatidylserine decarboxylase: role in Pdr3-dependent retrograde regulation of PDR5 expression. Mol Cell Biol 2008; 28:5851-64. [PMID: 18644857 DOI: 10.1128/mcb.00405-08] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multidrug resistance in the yeast Saccharomyces cerevisiae is sensitive to the mitochondrial genome status of cells. Cells that lose their organellar genome ([rho(0)] cells) dramatically induce transcription of multiple or pleiotropic drug resistance genes via increased expression of a zinc cluster-containing transcription factor designated Pdr3. A major Pdr3 target gene is the ATP-binding cassette transporter-encoding gene PDR5. Pdr5 has been demonstrated to act as a phospholipid floppase catalyzing the net outward movement of phosphatidylethanolamine (PE). Since the mitochondrially localized Psd1 enzyme provides a major route of PE biosynthesis, we evaluated the potential linkage between Psd1 function and PDR5 regulation. Overproduction of Psd1 in wild-type ([rho(+)]) cells was found to induce PDR5 transcription and drug resistance in a Pdr3-dependent manner. Loss of the PSD1 gene from [rho(0)] cells prevented the normal activation of PDR5 expression. Surprisingly, expression of a catalytically inactive form of Psd1 still supported PDR5 transcriptional activation, suggesting that PE levels were not the signal triggering PDR5 induction. Expression of green fluorescent protein fusions mapped the region required to induce PDR5 expression to the noncatalytic amino-terminal portion of Psd1. Psd1 is a novel bifunctional protein required both for PE biosynthesis and regulation of multidrug resistance.
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41
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Sarinová M, Straková V, Balková K, Gbelská Y. Decreased susceptibility to antifungals in respiratory-deficient Kluyveromyces lactis mutants. Folia Microbiol (Praha) 2008; 52:484-90. [PMID: 18298045 DOI: 10.1007/bf02932108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Decreased susceptibility of K. lactis mutants impaired in the function of cytochrome c, cytochrome c1 and cytochrome-c oxidase to fluconazole, bifonazole and amphotericin B in comparison with the isogenic wild-type strain was observed. Flow cytometry with rhodamine 6G did not show any changes in the accumulation of the dye in the mutant cells compared with the corresponding wild-type strain. Sterol analysis showed similar overall amount of sterols in both wild-type and mutant cells. Taking into account the increased amphotericin B resistance and significantly diminished susceptibility of mutant cells to lyticase digestion, the cell wall structure and/or composition may probably be responsible for the observed changes in the susceptibility of mutants to the antifungal compounds used.
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Affiliation(s)
- M Sarinová
- Department of Microbiology and Virology, Comenius University in Bratislava, 842 15 Bratislava, Slovakia
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42
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Batova M, Borecka-Melkusova S, Simockova M, Dzugasova V, Goffa E, Subik J. Functional characterization of the CgPGS1 gene reveals a link between mitochondrial phospholipid homeostasis and drug resistance in Candida glabrata. Curr Genet 2008; 53:313-22. [PMID: 18343926 DOI: 10.1007/s00294-008-0187-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 10/22/2022]
Abstract
Cardiolipin and its precursor phosphatidylglycerol are two anionic phospholipids that are essential for the biogenesis of functional mitochondria. To assess their role in mitochondrial and cellular functions in the pathogenic yeast Candida glabrata, a functional characterization of the CgPGS1 gene encoding the phosphatidylglycerolphosphate synthase has been carried out. Transposon insertion mutation in CgPGS1 resulted in the loss of phosphatidylglycerolphosphate synthase activity and in deficiency of both phosphatidylglycerol and cardiolipin. The Cgpgs1 Delta mutant cells displayed reduced amounts of cytochrome b and cytochrome a, and had impaired growth on minimal media containing non-fermentable carbon and energy sources. They did not grow at elevated temperatures and failed to form colonies after induction of mitochondrial DNA deletions. The mutant cells also displayed a decreased susceptibility to fluconazole, ketoconazole, clotrimazole, voriconazole and posaconazole. In the Cgpgs1 Delta mutant, a quantitative real time PCR revealed enhanced mRNA levels for multidrug resistance associated genes such as CgPDR1 encoding transcriptional activator and CgCDR1, CgPDH1 and CgSNQ2 coding for drug efflux transporters. These results indicate that CgPGS1 and anionic phospholipids are required for optimal mitochondrial functions and maintenance of yeast susceptibility to azole antifungals.
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Affiliation(s)
- Monika Batova
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina B-2, 842 15 Bratislava 4, Slovak Republic
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43
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Yeast adaptation to mancozeb involves the up-regulation of FLR1 under the coordinate control of Yap1, Rpn4, Pdr3, and Yrr1. Biochem Biophys Res Commun 2008; 367:249-55. [DOI: 10.1016/j.bbrc.2007.12.056] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 12/07/2007] [Indexed: 11/19/2022]
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44
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Sarinová M, Tichá E, Obernauerová M, Gbelská Y. Impact of mitochondrial function on yeast susceptibility to antifungal compounds. Folia Microbiol (Praha) 2007; 52:223-9. [PMID: 17702459 DOI: 10.1007/bf02931302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Saccharomyces cerevisiae pell and crd1 mutants deficient in the biosynthesis of mitochondrial phosphatidylglycerol (PG) and cardiolipin (CL) as well as Kluyveromyces lactis mutants impaired in the respiratory chain function (RCF) containing dysfunctional mitochondria show altered sensitivity to metabolic inhibitors. The S. cerevisiae pell mutant displayed increased sensitivity to cycloheximide, chloramphenicol, oligomycin and the cell-wall perturbing agents caffeine, caspofungin and hygromycin. On the other hand, the pel1 mutant was less sensitive to fluconazole, similarly as the K. lactis mutants impaired in the function of mitochondrial cytochromes. Mitochondrial dysfunction resulting either from the absence of PG and CL or impairment of the RCF presumably renders the cells more resistant to fluconazole. The increased tolerance of K. lactis respiratory chain mutants to amphotericin B, caffeine and hygromycin is probably related to a modification of the cell wall.
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Affiliation(s)
- M Sarinová
- Department of Microbiology and Virology, Faculty of Science, Comenius University, 842 15 Bratislava, Slovakia
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45
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Affiliation(s)
- Kailash Gulshan
- Department of Molecular Physiology and Biophysics, 6-530 Bowen Science Building, University of Iowa, Iowa City, IA 52242, USA
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46
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Shahi P, Gulshan K, Moye-Rowley WS. Negative Transcriptional Regulation of Multidrug Resistance Gene Expression by an Hsp70 Protein. J Biol Chem 2007; 282:26822-26831. [PMID: 17636264 DOI: 10.1074/jbc.m704772200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
One of the most common origins of multidrug resistance occurs via the overproduction of ATP-binding cassette (ABC) transporter proteins. These ABC transporters then act as broad specificity drug pumps and efflux a wide range of toxic agents out of the cell. The yeast Saccharomyces cerevisiae exhibits multiple or pleiotropic drug resistance (Pdr) often through the over-production of a plasma membrane-localized ABC transporter protein called Pdr5p. Expression of the PDR5 gene is controlled by two zinc cluster-containing transcription factors called Pdr1p and Pdr3p. Cells that lack their mitochondrial genome (rho(0) cells) strongly induce PDR5 transcription in a Pdr3p-dependent fashion. To identify proteins associated with Pdr3p that might act to regulate this factor, a tandem affinity purification (TAP) moiety was fused to Pdr3p, and this recombinant protein was purified from yeast cells. The cytosolic Hsp70 chaperone Ssa1p co-purified with TAP-Pdr3p. Overexpression of Ssa1p repressed expression of PDR5 but had no effect on expression of other genes involved in the Pdr phenotype. This Ssa1p-mediated repression required the presence of Pdr3p and did not influence Pdr1p-dependent gene expression. Loss of the nucleotide exchange factor Fes1p mimicked Ssa1p-mediated repression of PDR5. Co-immunoprecipitation experiments indicated that Ssa1p was associated with Pdr3p but not Pdr1p in yeast cells. Finally, rho(0) cells had less Ssa1p bound to Pdr3p than rho(+) cells, consistent with Ssa1p-mediated repression of Pdr3p activity serving as a key regulatory step in control of multidrug resistance in yeast.
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Affiliation(s)
- Puja Shahi
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242
| | - Kailash Gulshan
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242.
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47
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Sellem CH, Marsy S, Boivin A, Lemaire C, Sainsard-Chanet A. A mutation in the gene encoding cytochrome c1 leads to a decreased ROS content and to a long-lived phenotype in the filamentous fungus Podospora anserina. Fungal Genet Biol 2007; 44:648-58. [PMID: 17081785 DOI: 10.1016/j.fgb.2006.09.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Revised: 09/19/2006] [Accepted: 09/22/2006] [Indexed: 11/21/2022]
Abstract
We present here the properties of a complex III loss-of-function mutant of the filamentous fungus Podospora anserina. The mutation corresponds to a single substitution in the second intron of the gene cyc1 encoding cytochrome c(1), leading to a splicing defect. The cyc1-1 mutant is long-lived, exhibits a defect in ascospore pigmentation, has a reduced growth rate and a reduced ROS production associated with a stabilisation of its mitochondrial DNA. We also show that increased longevity is linked with morphologically modified mitochondria and an increased number of mitochondrial genomes. Overexpression of the alternative oxidase rescues all these phenotypes and restores aging. Interestingly, the absence of complex III in this mutant is not paralleled with a deficiency in complex I activity as reported in mammals although the respiratory chain of P. anserina has recently been demonstrated to be organized according to the "respirasome" model.
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Affiliation(s)
- Carole H Sellem
- Centre de Génétique Moléculaire, UPR 2167, CNRS, 1 avenue de la Terrasse, 91190 Gif-sur-Yvette, France
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48
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Abstract
Mitochondrial retrograde signaling is a pathway of communication from mitochondria to the nucleus under normal and pathophysiological conditions. The best understood of such pathways is retrograde signaling in the budding yeast Saccharomyces cerevisiae. It involves multiple factors that sense and transmit mitochondrial signals to effect changes in nuclear gene expression; these changes lead to a reconfiguration of metabolism to accommodate cells to defects in mitochondria. Analysis of regulatory factors has provided us with a mechanistic view of regulation of retrograde signaling. Here we review advances in the yeast retrograde signaling pathway and highlight its regulatory factors and regulatory mechanisms, its physiological functions, and its connection to nutrient sensing, TOR signaling, and aging.
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Affiliation(s)
- Zhengchang Liu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA.
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49
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Tsai HF, Krol AA, Sarti KE, Bennett JE. Candida glabrata PDR1, a transcriptional regulator of a pleiotropic drug resistance network, mediates azole resistance in clinical isolates and petite mutants. Antimicrob Agents Chemother 2006; 50:1384-92. [PMID: 16569856 PMCID: PMC1426987 DOI: 10.1128/aac.50.4.1384-1392.2006] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 01/18/2006] [Accepted: 01/26/2006] [Indexed: 11/20/2022] Open
Abstract
Candida glabrata, a yeast with intrinsically low susceptibility to azoles, frequently develops increased azole resistance during prolonged treatment. Transposon mutagenesis revealed that disruption of CgPDR1 resulted in an 8- to 16-fold increase in fluconazole susceptibility of C. glabrata. CgPDR1 is a homolog of Saccharomyces cerevisiae PDR1, which encodes a transcriptional regulator of multidrug transporters. Northern blot analyses indicated that CgPDR1 regulated both constitutive and drug-induced expression of CgCDR1, a multidrug transporter gene. In agreement with the Northern analysis, the Cgpdr1 mutant had increased rhodamine accumulation, in contrast to the decreased accumulation in the CgPDR1-overexpressing strain. Northern analyses also indicated the importance of CgPDR1 in fluconazole resistance arising during therapy. Two clinically resistant isolates had higher expression of CgPDR1 and CgCDR1 compared to their paired susceptible isolates. Integrative transformation of CgPDR1 from the two resistant isolates converted the Cgpdr1 mutant into azole-resistant strains with upregulated CgPDR1 expression. Two different amino acid substitutions, W297S in one isolate and F575L in the other, accounted for the upregulated CgPDR1 expression and the resistance. Finally, CgPDR1 was shown to be required for the azole resistance due to mitochondrial deficiency. Thus, CgPDR1 encodes a transcriptional regulator of a pleiotropic drug resistance network and contributes to the azole resistance of clinical isolates and petite mutants.
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Affiliation(s)
- Huei-Fung Tsai
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA
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50
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Dzugasová V, Subík J. Synthetic lethal interaction between the pel1 and op1 mutations in Saccharomyces cerevisiae. Folia Microbiol (Praha) 2006; 50:293-9. [PMID: 16408847 DOI: 10.1007/bf02931409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The Saccharomyces cerevisiae mutant strain containing the op1 mutation affecting the function of a mitochondrial ATP/ADP translocator has been crossed to the pel1 and crd1 mutants deficient in the biosynthesis of mitochondrial phosphatidylglycerol (PG) and cardiolipin (CL). Using tetrad analysis of diploids issued from corresponding crosses a synthetic lethal interaction has been observed between the op1 and pel1 mutations resulting in the lack of growth of a corresponding double mutant on minimal medium containing glucose. The op1 pel1 double mutant also displayed a decreased susceptibility to fluconazole and a compromised growth even in complex medium containing glucose. The viability of mutant cells was strongly reduced, corresponding to <30 % and 10 % of colony-forming units observed after growth in complex and minimal medium, respectively. A lower viability of the double mutant in minimal medium was accompanied by an increased formation of mitochondrial petite mutants (as determined by mtDNA rescue into diploid cells). The results indicate that in the simultaneous absence of mitochondrial anionic phospholipids (PG plus CL) and ATP/ADP exchange across the inner mitochondrial membrane the yeast mitochondrial functions are severely limited, leading to a strongly compromised cell multiplication. Since under similar conditions the op1 crd1 double mutant was able to grow on minimal medium this deleterious effect of anionic phospholipid deficiency could be at least partially substituted by PG accumulated in the cardiolipin deficient delta crd1 mutant cells.
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Affiliation(s)
- V Dzugasová
- Department of Microbiology and Virology, Faculty of Science, Comenius University, 842 15 Bratislava, Slovakia
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