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Barbosa PGP, Rosse I, Bessa MASEF, Silva DF, Saraiva MAF, Cunha AC, Moraes L, de Carvalho BT, Foulquié-Moreno MR, Thevelein JM, Trópia MJM, Castro IM, Brandão RL. Genomic approachesidentifySTT4 as a new component in glucose-induced activation of yeast plasma membrane H +-ATPase. Cell Calcium 2024; 123:102909. [PMID: 38861767 DOI: 10.1016/j.ceca.2024.102909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 06/13/2024]
Abstract
Many studies have focused on identifying the signaling pathway by which addition of glucose triggers post-translational activation of the plasma membrane H+-ATPase in yeast. They have revealed that calcium signaling is involved in the regulatory pathway, supported for instance by the phenotype of mutants inARG82 that encodes an inositol kinase that phosphorylates inositol triphosphate (IP3). Strong glucose-induced calcium signaling, and high glucose-induced plasma membrane H+-ATPase activation have been observed in a specific yeast strain with the PJ genetic background. In this study, we have applied pooled-segregant whole genome sequencing, QTL analysis and a new bioinformatics methodology for determining SNP frequencies to identify the cause of this discrepancy and possibly new components of the signaling pathway. This has led to the identification of an STT4 allele with 6 missense mutations as a major causative allele, further supported by the observation that deletion of STT4 in the inferior parent caused a similar increase in glucose-induced plasma membrane H+-ATPase activation. However, the effect on calcium signaling was different indicating the presence of additional relevant genetic differences between the superior and reference strains. Our results suggest that phosphatidylinositol-4-phosphate might play a role in the glucose-induced activation of plasma membrane H+-ATPase by controlling intracellular calcium release through the modulation of the activity of phospholipase C.
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Affiliation(s)
| | - Izinara Rosse
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia; Laboratório Multiusuário de Bioinformática, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | | | - Débora Faria Silva
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia
| | | | - Aureliano Claret Cunha
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia
| | - Lauro Moraes
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia; Laboratório Multiusuário de Bioinformática, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - Bruna Trindade de Carvalho
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium; Center for Microbiology, VIB, Leuven-Heverlee, Flanders, Belgium
| | - Maria R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium; Center for Microbiology, VIB, Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium; Center for Microbiology, VIB, Leuven-Heverlee, Flanders, Belgium
| | | | - Ieso Miranda Castro
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia
| | - Rogelio Lopes Brandão
- Laboratório de Biologia Celular e Molecular, Departamento de Farmácia, Escola de Farmácia.
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2
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Coleman CE, Landin C, Neuer A, Sayegh FM, Marshall PA. Calmodulin kinase 2 genetically interacts with Rch1p to negatively regulate calcium import into Saccharomyces cerevisiae after extracellular calcium pulse. Arch Microbiol 2022; 204:519. [DOI: 10.1007/s00203-022-03095-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 01/18/2023]
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Li W, Shrivastava M, Lu H, Jiang Y. Calcium-calcineurin signaling pathway in Candida albicans: A potential drug target. Microbiol Res 2021; 249:126786. [PMID: 33989979 DOI: 10.1016/j.micres.2021.126786] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/27/2021] [Accepted: 05/03/2021] [Indexed: 12/26/2022]
Abstract
Increased morbidity and mortality of candidiasis are a notable threat to the immunocompromised patients. At present, the types of drugs available to treat C. albicans infection are relatively limited. Moreover, the emergence of antifungal drug resistance of C. albicans makes the treatment of C. albicans infection more difficult. The calcium-calcineurin signaling pathway plays a crucial role in the survival and pathogenicity of C. albicans and may act as a potential target against C. albicans. In this review, we summarized functions of the calcium-calcineurin signaling pathway in several biological processes, compared the differences of this signaling pathway between C. albicans and humans, and described anti-C. albicans activity of inhibitors of this signaling pathway. We believe that targeting the calcium-calcineurin signaling pathway is a promising strategy to cope with C. albicans infection.
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Affiliation(s)
- Wanqian Li
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | | | - Hui Lu
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Yuanying Jiang
- Department of Pharmacology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
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4
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Lev S, Bowring B, Desmarini D, Djordjevic JT. Inositol polyphosphate-protein interactions: Implications for microbial pathogenicity. Cell Microbiol 2021; 23:e13325. [PMID: 33721399 PMCID: PMC9286782 DOI: 10.1111/cmi.13325] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/03/2021] [Accepted: 03/07/2021] [Indexed: 11/29/2022]
Abstract
Inositol polyphosphates (IPs) and inositol pyrophosphates (PP-IPs) regulate diverse cellular processes in eukaryotic cells. IPs and PP-IPs are highly negatively charged and exert their biological effects by interacting with specific protein targets. Studies performed predominantly in mammalian cells and model yeasts have shown that IPs and PP-IPs modulate target function through allosteric regulation, by promoting intra- and intermolecular stabilization and, in the case of PP-IPs, by donating a phosphate from their pyrophosphate (PP) group to the target protein. Technological advances in genetics have extended studies of IP function to microbial pathogens and demonstrated that disrupting PP-IP biosynthesis and PP-IP-protein interaction has a profound impact on pathogenicity. This review summarises the complexity of IP-mediated regulation in eukaryotes, including microbial pathogens. It also highlights examples of poor conservation of IP-protein interaction outcome despite the presence of conserved IP-binding domains in eukaryotic proteomes.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Bethany Bowring
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Julianne Teresa Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
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5
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Yong J, Zu R, Huang X, Ge Y, Li Y. Synergistic Effect of Berberine Hydrochloride and Fluconazole Against Candida albicans Resistant Isolates. Front Microbiol 2020; 11:1498. [PMID: 32714312 PMCID: PMC7343717 DOI: 10.3389/fmicb.2020.01498] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 06/09/2020] [Indexed: 12/02/2022] Open
Abstract
The emergence of resistant Candida albicans has made clinical fluconazole (FLC) treatment difficult. Improving sensitivity to FLC is an effective way to treat resistant isolates. Berberine hydrochloride (BBH) is a commonly used traditional Chinese medicine with antimicrobial effects, especially in resistant isolates. We investigated the molecular mechanisms underlying BBH and FLC synergism on biofilm-positive FLC-resistant C. albicans inhibition. Checkerboard microdilution assays and time-kill assays showed a strong synergistic effect between BBH and FLC in resistant C. albicans isolates, causing a significant 32–512-fold reduction in minimum inhibitory concentrations. BBH combined with FLC inhibited intracellular FLC efflux due to key efflux pump gene CDR1 downregulation, whereas FLC alone induced high CDR1 transcription in resistant strains. Further, BBH + FLC inhibited yeast adhesion, morphological hyphae transformation, and biofilm formation by downregulating the hyphal-specific genes ALS3, HWP1, and ECE1. BBH caused cytoplasmic Ca2+ influx, while FLC alone did not induce high intracellular Ca2+ levels. The vacuolar calcium channel gene YVC1 was upregulated, while the vacuolar calcium pump gene PMC1 was downregulated in the BBH + FLC and BBH alone groups. However, vacuolar calcium gene expression after FLC treatment was opposite in biofilm-positive FLC-resistant C. albicans, which might explain why BBH induces Ca2+ influx. These results demonstrate that BBH + FLC exerts synergistic effects to increase FLC sensitivity by regulating multiple targets in FLC-resistant C. albicans. These findings further show that traditional Chinese medicines have multi-target antimicrobial effects that may inhibit drug-resistant strains. This study also found that the vacuolar calcium regulation genes YVC1 and PMC1 are key BBH + FLC targets which increase cytoplasmic Ca2+ in resistant isolates, which might be critical for reversing biofilm-positive FLC-resistant C. albicans.
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Affiliation(s)
- Jiangyan Yong
- Chengdu University of Traditional Chinese Medicine, Chengdu, China.,Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ruiling Zu
- Sichuan Cancer Hospital and Institute, Chengdu, China
| | - Xiaoxue Huang
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yiman Ge
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yan Li
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Lev S, Li C, Desmarini D, Sorrell TC, Saiardi A, Djordjevic JT. Fungal Kinases With a Sweet Tooth: Pleiotropic Roles of Their Phosphorylated Inositol Sugar Products in the Pathogenicity of Cryptococcus neoformans Present Novel Drug Targeting Opportunities. Front Cell Infect Microbiol 2019; 9:248. [PMID: 31380293 PMCID: PMC6660261 DOI: 10.3389/fcimb.2019.00248] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/26/2019] [Indexed: 12/17/2022] Open
Abstract
Invasive fungal pathogens cause more than 300 million serious human infections and 1.6 million deaths per year. A clearer understanding of the mechanisms by which these fungi cause disease is needed to identify novel targets for urgently needed therapies. Kinases are key components of the signaling and metabolic circuitry of eukaryotic cells, which include fungi, and kinase inhibition is currently being exploited for the treatment of human diseases. Inhibiting evolutionarily divergent kinases in fungal pathogens is a promising avenue for antifungal drug development. One such group of kinases is the phospholipase C1-dependent inositol polyphosphate kinases (IPKs), which act sequentially to transfer a phosphoryl group to a pre-phosphorylated inositol sugar (IP). This review focuses on the roles of fungal IPKs and their IP products in fungal pathogenicity, as determined predominantly from studies performed in the model fungal pathogen Cryptococcus neoformans, and compares them to what is known in non-pathogenic model fungi and mammalian cells to highlight potential drug targeting opportunities.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Cecilia Li
- Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology-Public Health, NSW Health Pathology, Westmead Hospital, Sydney, NSW, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Tania C Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
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7
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Li Y, Zhang Y, Lu L. Calcium signaling pathway is involved in non-CYP51 azole resistance in Aspergillus fumigatus. Med Mycol 2019; 57:S233-S238. [PMID: 30816964 DOI: 10.1093/mmy/myy075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022] Open
Abstract
The opportunistic fungal pathogen Aspergillus fumigatus, which is one of the primary airborne ascomycete pathogens and allergens worldwide, causes invasive fungal infections, which have high morbidity and mortality rates among immunosuppressed patients. The abuse of azole antifungals results in serious drug resistance in clinical therapy. Thus, a thorough understanding of the azole drug resistance mechanism and screening of antifungal agents with a novel mode of action and new drug targets are required to fight against drug resistance. Current studies suggest that there are three major azole resistance mechanisms in fungal pathogens, including changes of the drug target Cyp51, activation of drug efflux pumps and induction of cellular stress responses. Fungi must adapt to a variety of external environmental stressors to survive. These obstacles include stress to the plasma membrane after azole antifungal treatments, high temperature, pH variation, and oxidative stress. As a filamentous fungus, A. fumigatus has evolved numerous signal-transduction systems to sense and respond to azole stresses to survive and proliferate in harsh environmental conditions. Among these signal-transduction systems, the Ca2+ signaling pathway is one of the most important response systems, which has been verified to be involved in stress adaptation. In this review, we have summarized how the components of the calcium-signaling pathway and their interaction network are involved in azole stress response in A. fumigatus.
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Affiliation(s)
- Yeqi Li
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Yuanwei Zhang
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ling Lu
- Jiangsu Key laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
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A Noisy Analog-to-Digital Converter Connects Cytosolic Calcium Bursts to Transcription Factor Nuclear Localization Pulses in Yeast. G3-GENES GENOMES GENETICS 2019; 9:561-570. [PMID: 30573469 PMCID: PMC6385971 DOI: 10.1534/g3.118.200841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Several examples of transcription factors that show stochastic, unsynchronized pulses of nuclear localization have been described. Here we show that under constant calcium stress, nuclear localization pulses of the transcription factor Crz1 follow stochastic variations in cytosolic calcium concentration. We find that the size of the stochastic calcium bursts is positively correlated with the number of subsequent Crz1 pulses. Based on our observations, we propose a simple stochastic model of how the signaling pathway converts a constant external calcium concentration into a digital number of Crz1 pulses in the nucleus, due to the time delay from nuclear transport and the stochastic decoherence of individual Crz1 molecule dynamics. We find support for several additional predictions of the model and suggest that stochastic input to nuclear transport may produce noisy digital responses to analog signals in other signaling systems.
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Identification of Inhibitory Ca 2+ Binding Sites in the Upper Vestibule of the Yeast Vacuolar TRP Channel. iScience 2018; 11:1-12. [PMID: 30572205 PMCID: PMC6299153 DOI: 10.1016/j.isci.2018.11.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/30/2018] [Accepted: 11/29/2018] [Indexed: 01/28/2023] Open
Abstract
By vacuolar patch-clamp and Ca2+ imaging experiments, we show that the yeast vacuolar transient receptor potential (TRPY) channel 1 is activated by cytosolic Ca2+ and inhibited by Ca2+ from the vacuolar lumen. The channel is cooperatively affected by vacuolar Ca2+ (Hill coefficient, 1.5), suggesting that it may accommodate a Ca2+ receptor that can bind two calcium ions. Alanine scanning of six negatively charged amino acid residues in the transmembrane S5 and S6 linker, facing the vacuolar lumen, revealed that two aspartate residues, 401 and 405, are essential for current inhibition and direct binding of 45Ca2+. Expressed in HEK-293 cells, a significant fraction of TRPY1, present in the plasma membrane, retained its Ca2+ sensitivity. Based on these data and on homology with TRPV channels, we conclude that D401 and D405 are key residues within the vacuolar vestibule of the TRPY1 pore that decrease cation access or permeation after Ca2+ binding. The yeast vacuolar TRPY1 channel is inhibited by vacuolar Ca2+ Aspartate residues D401A and D405A are essential for Ca2+-mediated inhibition Aspartate residues D401 and D405 are essential for direct Ca2+ binding Ca2+ binding to D401 and D405 within vacuolar pore vestibule mediates inhibition
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Castanheira DD, Santana EP, Godoy-Santos F, Diniz RHS, Faria-Oliveira F, Pereira RR, Trópia MJM, Castro IM, Brandão RL. Lpx1p links glucose-induced calcium signaling and plasma membrane H+-ATPase activation in Saccharomyces cerevisiae cells. FEMS Yeast Res 2018; 18:4643176. [PMID: 29177424 DOI: 10.1093/femsyr/fox088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 11/17/2017] [Indexed: 11/12/2022] Open
Abstract
In yeast, as in other eukaryotes, calcium plays an essential role in signaling transduction to regulate different processes. Many pieces of evidence suggest that glucose-induced activation of plasma membrane H+-ATPase, essential for yeast physiology, is related to calcium signaling. Until now, no protein that could be regulated by calcium in this context has been identified. Lpx1p, a serine-protease that is also involved in the glucose-induced activation of the plasma membrane H+-ATPase, could be a candidate to respond to intracellular calcium signaling involved in this process. In this work, by using different approaches, we obtained many pieces of evidence suggesting that the requirement of calcium signaling for activation of the plasma membrane H+-ATPase is due to its requirement for activation of Lpx1p. According to the current model, activation of Lpx1p would cause hydrolysis of an acetylated tubulin that maintains the plasma membrane H+-ATPase in an inactive state. Therefore, after its activation, Lpx1p would hydrolyze the acetylated tubulin making the plasma membrane H+-ATPase accessible for phosphorylation by at least one protein kinase.
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Affiliation(s)
- Diogo Dias Castanheira
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Eduardo Perovano Santana
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Fernanda Godoy-Santos
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Raphael Hermano Santos Diniz
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Fábio Faria-Oliveira
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Renata Rebeca Pereira
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Maria José Magalhães Trópia
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Ieso Miranda Castro
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
| | - Rogelio Lopes Brandão
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisas em Ciências Biológicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-000, Brazil
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Deprez MA, Eskes E, Wilms T, Ludovico P, Winderickx J. pH homeostasis links the nutrient sensing PKA/TORC1/Sch9 ménage-à-trois to stress tolerance and longevity. MICROBIAL CELL 2018; 5:119-136. [PMID: 29487859 PMCID: PMC5826700 DOI: 10.15698/mic2018.03.618] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The plasma membrane H+-ATPase Pma1 and the vacuolar V-ATPase act in close harmony to tightly control pH homeostasis, which is essential for a vast number of physiological processes. As these main two regulators of pH are responsive to the nutritional status of the cell, it seems evident that pH homeostasis acts in conjunction with nutrient-induced signalling pathways. Indeed, both PKA and the TORC1-Sch9 axis influence the proton pumping activity of the V-ATPase and possibly also of Pma1. In addition, it recently became clear that the proton acts as a second messenger to signal glucose availability via the V-ATPase to PKA and TORC1-Sch9. Given the prominent role of nutrient signalling in longevity, it is not surprising that pH homeostasis has been linked to ageing and longevity as well. A first indication is provided by acetic acid, whose uptake by the cell induces toxicity and affects longevity. Secondly, vacuolar acidity has been linked to autophagic processes, including mitophagy. In agreement with this, a decline in vacuolar acidity was shown to induce mitochondrial dysfunction and shorten lifespan. In addition, the asymmetric inheritance of Pma1 has been associated with replicative ageing and this again links to repercussions on vacuolar pH. Taken together, accumulating evidence indicates that pH homeostasis plays a prominent role in the determination of ageing and longevity, thereby providing new perspectives and avenues to explore the underlying molecular mechanisms.
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Affiliation(s)
| | - Elja Eskes
- Functional Biology, KU Leuven, Leuven, Belgium
| | | | - Paula Ludovico
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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CgMED3 Changes Membrane Sterol Composition To Help Candida glabrata Tolerate Low-pH Stress. Appl Environ Microbiol 2017; 83:AEM.00972-17. [PMID: 28667115 DOI: 10.1128/aem.00972-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Candida glabrata is a promising microorganism for organic acid production. The present study aimed to investigate the role of C. glabrata Mediator complex subunit 3 (CgMed3p) in protecting C. glabrata under low-pH conditions. To this end, genes CgMED3A and CgMED3B were deleted, resulting in the double-deletion Cgmed3ABΔ strain. The final biomass and cell viability levels of Cgmed3ABΔ decreased by 64.5% and 35.8%, respectively, compared to the wild-type strain results at pH 2.0. In addition, lack of CgMed3ABp resulted in selective repression of a subset of genes in the lipid biosynthesis and metabolism pathways. Furthermore, C18:1, lanosterol, zymosterol, fecosterol, and ergosterol were 13.2%, 80.4%, 40.4%, 78.1%, and 70.4% less abundant, respectively, in the Cgmed3ABΔ strain. In contrast, the concentration of squalene increased by about 44.6-fold. As a result, membrane integrity, rigidity, and H+-ATPase activity in the Cgmed3ABΔ strain were reduced by 62.7%, 13.0%, and 50.3%, respectively. In contrast, overexpression of CgMED3AB increased the levels of C18:0, C18:1, and ergosterol by 113.2%, 5.9%, and 26.4%, respectively. Moreover, compared to the wild-type results, dry cell weight and pyruvate production increased, irrespective of pH buffering. These results suggest that CgMED3AB regulates membrane composition, which in turn enables cells to tolerate low-pH stress. We propose that regulation of CgMed3ABp may provide a novel strategy for enhancing low-pH tolerance and increasing organic acid production by C. glabrataIMPORTANCE The objective of this study was to investigate the role of Candida glabrata Mediator complex subunit 3 (CgMed3ABp) and its regulation of gene expression at low pH in C. glabrata We found that CgMed3ABp was critical for cellular survival and pyruvate production during low-pH stress. Measures of the levels of plasma membrane fatty acids and sterol composition indicated that CgMed3ABp could play an important role in regulating homeostasis in C. glabrata We propose that controlling membrane lipid composition may enhance the robustness of C. glabrata for the production of organic acids.
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Role of the Inositol Polyphosphate Multikinase Ipk2 in Regulation of Hyphal Development, Calcium Signaling and Secretion in Candida albicans. Mycopathologia 2017; 182:609-623. [DOI: 10.1007/s11046-017-0138-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 04/12/2017] [Indexed: 10/19/2022]
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Yenush L. Potassium and Sodium Transport in Yeast. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:187-228. [DOI: 10.1007/978-3-319-25304-6_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Mazón MJ, Eraso P, Portillo F. Specific phosphoantibodies reveal two phosphorylation sites in yeast Pma1 in response to glucose. FEMS Yeast Res 2015; 15:fov030. [PMID: 26019146 DOI: 10.1093/femsyr/fov030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2015] [Indexed: 11/14/2022] Open
Abstract
Glucose triggers post-translational modifications of the Saccharomyces cerevisiae plasma membrane H(+)-ATPase (Pma1) that lead to an increase in enzyme activity. The activation results from changes in two kinetic parameters: an increase in the affinity of the enzyme for ATP, depending on Ser899, and an increase in the Vmax involving Ser911/Thr912. Using phosphospecific antibodies, we show that Ser899 and Ser911/Thr912 are phosphorylated in vivo during glucose activation and that protein phosphatase Glc7 is involved in the dephosphorylation of Ser899 upon glucose starvation.
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Affiliation(s)
- María J Mazón
- Departamento de Bioquímica and Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier, 4, 28029 Madrid, Spain
| | - Pilar Eraso
- Departamento de Bioquímica and Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier, 4, 28029 Madrid, Spain
| | - Francisco Portillo
- Departamento de Bioquímica and Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier, 4, 28029 Madrid, Spain
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16
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Pereira RR, Castanheira D, Teixeira JA, Bouillet LEM, Ribeiro EMC, Trópia MMJ, Alvarez F, Correa LFM, Mota BEF, Conceição LEFR, Castro IM, Brandão RL. Detailed search for protein kinase(s) involved in plasma membrane H+−ATPase activity regulation of yeast cells. FEMS Yeast Res 2015; 15:fov003. [DOI: 10.1093/femsyr/fov003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Rigamonti M, Groppi S, Belotti F, Ambrosini R, Filippi G, Martegani E, Tisi R. Hypotonic stress-induced calcium signaling in Saccharomyces cerevisiae involves TRP-like transporters on the endoplasmic reticulum membrane. Cell Calcium 2015; 57:57-68. [DOI: 10.1016/j.ceca.2014.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/05/2014] [Accepted: 12/06/2014] [Indexed: 11/28/2022]
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18
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 and 1880=1880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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19
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 1-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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20
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 8029-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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21
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 8029-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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22
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 1-- gadu] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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23
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 1-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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24
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014. [DOI: 10.1186/1471-2164-15-552 order by 8029-- awyx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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25
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Walker ME, Nguyen TD, Liccioli T, Schmid F, Kalatzis N, Sundstrom JF, Gardner JM, Jiranek V. Genome-wide identification of the Fermentome; genes required for successful and timely completion of wine-like fermentation by Saccharomyces cerevisiae. BMC Genomics 2014; 15:552. [PMID: 24993029 PMCID: PMC4099481 DOI: 10.1186/1471-2164-15-552] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 06/27/2014] [Indexed: 12/21/2022] Open
Abstract
Background Wine fermentation is a harsh ecological niche to which wine yeast are well adapted. The initial high osmotic pressure and acidity of grape juice is followed by nutrient depletion and increasing concentrations of ethanol as the fermentation progresses. Yeast’s adaptation to these and many other environmental stresses, enables successful completion of high-sugar fermentations. Earlier transcriptomic and growth studies have tentatively identified genes important for high-sugar fermentation. Whilst useful, such studies did not consider extended growth (>5 days) in a temporally dynamic multi-stressor environment such as that found in many industrial fermentation processes. Here, we identify genes whose deletion has minimal or no effect on growth, but results in failure to achieve timely completion of the fermentation of a chemically defined grape juice with 200 g L−1 total sugar. Results Micro- and laboratory-scale experimental fermentations were conducted to identify 72 clones from ~5,100 homozygous diploid single-gene yeast deletants, which exhibited protracted fermentation in a high-sugar medium. Another 21 clones (related by gene function, but initially eliminated from the screen because of possible growth defects) were also included. Clustering and numerical enrichment of genes annotated to specific Gene Ontology (GO) terms highlighted the vacuole’s role in ion homeostasis and pH regulation, through vacuole acidification. Conclusion We have identified 93 genes whose deletion resulted in the duration of fermentation being at least 20% longer than the wild type. An extreme phenotype, ‘stuck’ fermentation, was also observed when DOA4, NPT1, PLC1, PTK2, SIN3, SSQ1, TPS1, TPS2 or ZAP1 were deleted. These 93 Fermentation Essential Genes (FEG) are required to complete an extended high-sugar (wine-like) fermentation. Their importance is highlighted in our Fermentation Relevant Yeast Genes (FRYG) database, generated from literature and the fermentation-relevant phenotypic characteristics of null mutants described in the Saccharomyces Genome Database. The 93-gene set is collectively referred to as the ‘Fermentome’. The fact that 10 genes highlighted in this study have not previously been linked to fermentation-related stresses, supports our experimental rationale. These findings, together with investigations of the genetic diversity of industrial strains, are crucial for understanding the mechanisms behind yeast’s response and adaptation to stresses imposed during high-sugar fermentations. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-552) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | - Vladimir Jiranek
- School of Agriculture, Food and Wine, University of Adelaide, Urrbrae, SA 5064, Australia.
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26
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Sasser TL, Fratti RA. Class C ABC transporters and Saccharomyces cerevisiae vacuole fusion. CELLULAR LOGISTICS 2014; 4:e943588. [PMID: 25610719 DOI: 10.4161/21592780.2014.943588] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 06/18/2014] [Indexed: 01/05/2023]
Abstract
Membrane fusion is carried out by core machinery that is conserved throughout eukaryotes. This is comprised of Rab GTPases and their effectors, and SNARE proteins, which together are sufficient to drive the fusion of reconstituted proteoliposomes. However, an outer layer of factors that are specific to individual trafficking pathways in vivo regulates the spatial and temporal occurrence of fusion. The homotypic fusion of Saccharomyces cerevisiae vacuolar lysosomes utilizes a growing set of factors to regulate the fusion machinery that include members of the ATP binding cassette (ABC) transporter family. Yeast vacuoles have five class C ABC transporters that are known to transport a variety of toxins into the vacuole lumen as part of detoxifying the cell. We have found that ABCC transporters can also regulate vacuole fusion through novel mechanisms. For instance Ybt1 serves as negative regulator of fusion through its effects on vacuolar Ca2+ homeostasis. Additional studies showed that Ycf1 acts as a positive regulator by affecting the efficient recruitment of the SNARE Vam7. Finally, we discuss the potential interface between the translocation of lipids across the membrane bilayer, also known as lipid flipping, and the efficiency of fusion.
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Key Words
- ABC, ATP binding cassette
- Bpt1
- Ca2+ homeostasis
- DAG, diacylglycerol
- HOPS, homotypic fusion and vacuole protein sorting complex
- MDR, multidrug resistance
- MSD, membrane spanning domain
- NBD, nucleotide binding domain
- Nft1
- PA, phosphatidic acid
- PC, phosphatidylcholine
- PE, phosphatidylethanolamine
- PI(3, 5)P2, phosphatidylinositol 3, 5-bisphosphate
- PI, phosphatidylinositol
- PI3P
- PI3P, phosphatidylinositol 3-phosphate
- PS, phosphatidylserine
- PX, phox homology
- SNARE
- SNARE, soluble N-ethylmaleimide-sensitive factor attachment protein receptors
- Vam7
- Vmr1
- Ybt1
- Ycf1
- lipid flipping
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Affiliation(s)
- Terry L Sasser
- Department of Biochemistry; University of Illinois at Urbana-Champaign ; Urbana, IL USA
| | - Rutilio A Fratti
- Department of Biochemistry; University of Illinois at Urbana-Champaign ; Urbana, IL USA
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Yu Q, Xiao C, Zhang K, Jia C, Ding X, Zhang B, Wang Y, Li M. The calcium channel blocker verapamil inhibits oxidative stress response in Candida albicans. Mycopathologia 2014; 177:167-77. [PMID: 24577794 DOI: 10.1007/s11046-014-9735-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 02/19/2014] [Indexed: 10/25/2022]
Abstract
Candida albicans is a common opportunistic fungal pathogen, causing both superficial candidiasis and life-threatening systemic infections in immune-compromised individuals. Calcium signaling is responsible for this pathogen in responding to several stresses, such as antifungal drugs, alkaline pH and membrane-perturbing agents. Our recent study revealed that it is also involved in oxidative stress response. In this study, we investigated the effect of verapamil, an L-type voltage-gated calcium channel blocker, on oxidative stress response in this fungus. The addition of verapamil resulted in increased sensitivity to the oxidative agent H2O2, which is associated with a decrease of calcium fluctuation under the stress. Moreover, this agent caused enhanced oxidative stress, with increased levels of ROS and enhanced dysfunction of the mitochondria under the oxidative stress. Further investigations in SOD activity, GSH contents and expression of oxidative stress response-related genes indicated that the effect of verapamil is related to the repression of oxidative stress response. Our findings demonstrated that verapamil has an inhibitory effect on oxidative stress response, confirming the relationship between calcium signaling and oxidative stress in C. albicans. Therefore, calcium channels may be potential targets for therapy to enhance the efficacy of oxidative stress against C. albicans-related infections.
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Affiliation(s)
- Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, Tianjin, 300071, People's Republic of China
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Abstract
All living organisms require nutrient minerals for growth and have developed mechanisms to acquire, utilize, and store nutrient minerals effectively. In the aqueous cellular environment, these elements exist as charged ions that, together with protons and hydroxide ions, facilitate biochemical reactions and establish the electrochemical gradients across membranes that drive cellular processes such as transport and ATP synthesis. Metal ions serve as essential enzyme cofactors and perform both structural and signaling roles within cells. However, because these ions can also be toxic, cells have developed sophisticated homeostatic mechanisms to regulate their levels and avoid toxicity. Studies in Saccharomyces cerevisiae have characterized many of the gene products and processes responsible for acquiring, utilizing, storing, and regulating levels of these ions. Findings in this model organism have often allowed the corresponding machinery in humans to be identified and have provided insights into diseases that result from defects in ion homeostasis. This review summarizes our current understanding of how cation balance is achieved and modulated in baker's yeast. Control of intracellular pH is discussed, as well as uptake, storage, and efflux mechanisms for the alkali metal cations, Na(+) and K(+), the divalent cations, Ca(2+) and Mg(2+), and the trace metal ions, Fe(2+), Zn(2+), Cu(2+), and Mn(2+). Signal transduction pathways that are regulated by pH and Ca(2+) are reviewed, as well as the mechanisms that allow cells to maintain appropriate intracellular cation concentrations when challenged by extreme conditions, i.e., either limited availability or toxic levels in the environment.
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V-ATPase dysfunction suppresses polyphosphate synthesis in Saccharomyces cerevisiae. Folia Microbiol (Praha) 2013; 58:437-41. [PMID: 23371743 DOI: 10.1007/s12223-013-0226-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Accepted: 01/21/2013] [Indexed: 10/27/2022]
Abstract
The yeast Saccharomyces cerevisiae accumulates the high levels of inorganic polyphosphates (polyPs) performing in the cells numerous functions, including phosphate and energy storage. The effects of vacuolar membrane ATPase (V-ATPase) dysfunction were studied on polyP accumulation under short-term cultivation in the Pi-excess media after Pi starvation. The addition of bafilomycin A1, a specific inhibitor of V-ATPase, to the medium with glucose resulted in strong inhibition of the synthesis of long-chain polyP and in substantial suppression of short-chain polyP. The addition of bafilomycin to the medium with ethanol resulted in decreased accumulation of high-molecular polyP, while the accumulation of low-molecular polyP was not affected. The levels of polyP synthesis in the mutant strain with a deletion in the vma2 gene encoding a V-ATPase subunit were significantly lower than in the parent strain in the media with glucose and with ethanol. The synthesis of the longest chain polyP was not observed in the mutant cells. The synthesis of only the low-polymer acid-soluble polyP fraction occurred in the cells of the mutant strain. However, the level of polyP1 was nearly tenfold lower than compared to the cells of the parent strain. Both bafilomycin A1 and the mutation in vacuolar ATPase subunit vma2 lead to a considerable decrease of cellular polyP accumulation. Thus, the defects in ΔμH(+) formation on the vacuolar membrane resulted in the decrease of polyP biosynthesis in S. cerevisiae.
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