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Campero-Basaldua C, González J, García JA, Ramírez E, Hernández H, Aguirre B, Torres-Ramírez N, Márquez D, Sánchez NS, Gómez-Hernández N, Torres-Machorro AL, Riego-Ruiz L, Scazzocchio C, González A. Neo-functionalization in Saccharomyces cerevisiae: a novel Nrg1-Rtg3 chimeric transcriptional modulator is essential to maintain mitochondrial DNA integrity. ROYAL SOCIETY OPEN SCIENCE 2023; 10:231209. [PMID: 37920568 PMCID: PMC10618058 DOI: 10.1098/rsos.231209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/11/2023] [Indexed: 11/04/2023]
Abstract
In Saccharomyces cerevisiae, the transcriptional repressor Nrg1 (Negative Regulator of Glucose-repressed genes) and the β-Zip transcription factor Rtg3 (ReTroGrade regulation) mediate glucose repression and signalling from the mitochondria to the nucleus, respectively. Here, we show a novel function of these two proteins, in which alanine promotes the formation of a chimeric Nrg1/Rtg3 regulator that represses the ALT2 gene (encoding an alanine transaminase paralog of unknown function). An NRG1/NRG2 paralogous pair, resulting from a post-wide genome small-scale duplication event, is present in the Saccharomyces genus. Neo-functionalization of only one paralog resulted in the ability of Nrg1 to interact with Rtg3. Both nrg1Δ and rtg3Δ single mutant strains were unable to use ethanol and showed a typical petite (small) phenotype on glucose. Neither of the wild-type genes complemented the petite phenotype, suggesting irreversible mitochondrial DNA damage in these mutants. Neither nrg1Δ nor rtg3Δ mutant strains expressed genes encoded by any of the five polycistronic units transcribed from mitochondrial DNA in S. cerevisiae. This, and the direct measurement of the mitochondrial DNA gene complement, confirmed that irreversible damage of the mitochondrial DNA occurred in both mutant strains, which is consistent with the essential role of the chimeric Nrg1/Rtg3 regulator in mitochondrial DNA maintenance.
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Affiliation(s)
- Carlos Campero-Basaldua
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - James González
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Janeth Alejandra García
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Edgar Ramírez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Hugo Hernández
- Departamento de Biología, Facultad de Química, UNAM, México City, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Beatriz Aguirre
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Nayeli Torres-Ramírez
- Laboratorio de Microscopía Electrónica Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Dariel Márquez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Norma Silvia Sánchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
| | - Nicolás Gómez-Hernández
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, SLP, México
| | - Ana Lilia Torres-Machorro
- Laboratorio de Biología Celular, Departamento de Investigación en Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias ‘Ismael Cosío Villegas', Tlalpan, Mexico
| | - Lina Riego-Ruiz
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, SLP, México
| | - Claudio Scazzocchio
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Alicia González
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular Universidad Nacional Autónoma de México, Ciudad de Mexi, México
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Padilla-Garfias F, Ríos-Cifuentes L, Sánchez NS, Calahorra M, Peña A. Study of the mechanism of ε-poly-l-lysine as an antifungal on Candida albicans and Saccharomyces cerevisiae. Biochim Biophys Acta Gen Subj 2022; 1866:130197. [PMID: 35732210 DOI: 10.1016/j.bbagen.2022.130197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 10/17/2022]
Abstract
The antimicrobial activity of ε-poly-l-lysine (EPL) has been documented, but its antifungal activity on yeast is not well defined and its mechanism of action has been vaguely explained. Our studies revealed that on both, Candida albicans and Saccharomyces cerevisiae, the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were 250 μg·mL-1; EPL produced a K+ and Ca2+ efflux, and at higher concentrations also an efflux of material absorbing at 260 nm, small peptides, and phosphate is produced, along with the inhibition of fermentation and extracellular acidification and respiration. Moreover, growth was inhibited, reactive oxygen species (ROS) production increased, and cell viability decreased. The polycation also produced plasma membrane potential hyperpolarization. The effects were dependent both on the cell quantity and polycation concentration, as well as the media used. The plasma membrane disruption was confirmed by TEM and PI staining.
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Affiliation(s)
- Francisco Padilla-Garfias
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, CDMX, 04510, México, CDMX, Mexico
| | - Laura Ríos-Cifuentes
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, CDMX, 04510, México, CDMX, Mexico
| | - Norma Silvia Sánchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, CDMX, 04510, México, CDMX, Mexico
| | - Martha Calahorra
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, CDMX, 04510, México, CDMX, Mexico
| | - Antonio Peña
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, CDMX, 04510, México, CDMX, Mexico.
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Márquez D, Escalera-Fanjul X, El Hafidi M, Aguirre-López B, Riego-Ruiz L, González A. Alanine Represses γ-Aminobutyric Acid Utilization and Induces Alanine Transaminase Required for Mitochondrial Function in Saccharomyces cerevisiae. Front Microbiol 2021; 12:695382. [PMID: 34421848 PMCID: PMC8371705 DOI: 10.3389/fmicb.2021.695382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/05/2021] [Indexed: 11/24/2022] Open
Abstract
The γ-aminobutyric acid (GABA) shunt constitutes a conserved metabolic route generating nicotinamide adenine dinucleotide phosphate (NADPH) and regulating stress response in most organisms. Here we show that in the presence of GABA, Saccharomyces cerevisiae produces glutamate and alanine through the irreversible action of Uga1 transaminase. Alanine induces expression of alanine transaminase (ALT1) gene. In an alt1Δ mutant grown on GABA, alanine accumulation leads to repression of the GAD1, UGA1, and UGA2 genes, involved in the GABA shunt, which could result in growth impairment. Induced ALT1 expression and negative modulation of the GABA shunt by alanine constitute a novel regulatory circuit controlling both alanine biosynthesis and catabolism. Consistent with this, the GABA shunt and the production of NADPH are repressed in a wild-type strain grown in alanine, as compared to those detected in the wild-type strain grown on GABA. We also show that heat shock induces alanine biosynthesis and ALT1, UGA1, UGA2, and GAD1 gene expression, whereas an uga1Δ mutant shows heat sensitivity and reduced NADPH pools, as compared with those observed in the wild-type strain. Additionally, an alt1Δ mutant shows an unexpected alanine-independent phenotype, displaying null expression of mitochondrial COX2, COX3, and ATP6 genes and a notable decrease in mitochondrial/nuclear DNA ratio, as compared to a wild-type strain, which results in a petite phenotype. Our results uncover a new negative role of alanine in stress defense, repressing the transcription of the GABA shunt genes, and support a novel Alt1 moonlighting function related to the maintenance of mitochondrial DNA integrity and mitochondrial gene expression.
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Affiliation(s)
- Dariel Márquez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
| | | | - Mohammed El Hafidi
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, Mexico
| | - Beatriz Aguirre-López
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Lina Riego-Ruiz
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, México
| | - Alicia González
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
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Abstract
Of the many microbial species on earth, only a small number are able to thrive in humans and cause disease. Comparison of closely related pathogenic and nonpathogenic species can therefore be useful in identifying key features that contribute to virulence. We created interspecies hybrids between Candida albicans, a prevalent fungal pathogen of humans, and Candida dubliniensis, a close, but much less pathogenic, relative. By comparing genome-wide expression differences between the two genomes in the same cell, we surmised that since the two species diverged from a common ancestor, natural selection has acted upon the expression level of an ancient metabolic pathway, illustrating that pathogenicity traits can arise over evolutionary timescales through small expression changes in deeply conserved proteins. Candida albicans is the most common cause of systemic fungal infections in humans and is considerably more virulent than its closest known relative, Candida dubliniensis. To investigate this difference, we constructed interspecies hybrids and quantified mRNA levels produced from each genome in the hybrid. This approach systematically identified expression differences in orthologous genes arising from cis-regulatory sequence changes that accumulated since the two species last shared a common ancestor, some 10 million y ago. We documented many orthologous gene-expression differences between the two species, and we pursued one striking observation: All 15 genes coding for the enzymes of glycolysis showed higher expression from the C. albicans genome than the C. dubliniensis genome in the interspecies hybrid. This pattern requires evolutionary changes to have occurred at each gene; the fact that they all act in the same direction strongly indicates lineage-specific natural selection as the underlying cause. To test whether these expression differences contribute to virulence, we created a C. dubliniensis strain in which all 15 glycolysis genes were produced at modestly elevated levels and found that this strain had significantly increased virulence in the standard mouse model of systemic infection. These results indicate that small expression differences across a deeply conserved set of metabolism enzymes can play a significant role in the evolution of virulence in fungal pathogens.
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Lev S, Li C, Desmarini D, Liuwantara D, Sorrell TC, Hawthorne WJ, Djordjevic JT. Monitoring Glycolysis and Respiration Highlights Metabolic Inflexibility of Cryptococcus neoformans. Pathogens 2020; 9:pathogens9090684. [PMID: 32839374 PMCID: PMC7559270 DOI: 10.3390/pathogens9090684] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/13/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus neoformans is a human fungal pathogen that adapts its metabolism to cope with limited oxygen availability, nutrient deprivation and host phagocytes. To gain insight into cryptococcal metabolism, we optimized a protocol for the Seahorse Analyzer, which measures extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) as indications of glycolytic and respiratory activities. In doing so we achieved effective immobilization of encapsulated cryptococci, established Rotenone/Antimycin A and 2-deoxyglucose as effective inhibitors of mitochondrial respiration and glycolysis, respectively, and optimized a microscopy-based method of data normalization. We applied the protocol to monitor metabolic changes in the pathogen alone and in co-culture with human blood-derived monocytes. We also compared metabolic flux in wild-type C. neoformans, its isogenic 5-PP-IP5/IP7-deficient metabolic mutant kcs1∆, the sister species of C. neoformans, Cryptococcus deuterogattii/VGII, and two other yeasts, Saccharomyces cerevisiae and Candida albicans. Our findings show that in contrast to monocytes and C. albicans, glycolysis and respiration are tightly coupled in C. neoformans and C. deuterogattii, as no compensatory increase in glycolysis occurred following inhibition of respiration. We also demonstrate that kcs1∆ has reduced metabolic activity that correlates with reduced mitochondrial function. Metabolic inflexibility in C. neoformans is therefore consistent with its obligate aerobe status and coincides with phagocyte tolerance of ingested cryptococcal cells.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (S.L.); (C.L.); (D.D.); (T.C.S.)
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW 2050, Australia
| | - Cecilia Li
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (S.L.); (C.L.); (D.D.); (T.C.S.)
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (S.L.); (C.L.); (D.D.); (T.C.S.)
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW 2050, Australia
| | - David Liuwantara
- Centre for Transplant and Renal Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia;
| | - Tania C. Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (S.L.); (C.L.); (D.D.); (T.C.S.)
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW 2050, Australia
| | - Wayne J. Hawthorne
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
- Centre for Transplant and Renal Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia;
| | - Julianne T. Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (S.L.); (C.L.); (D.D.); (T.C.S.)
- Sydney Medical School—Westmead, The University of Sydney, Westmead, NSW 2145, Australia;
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW 2050, Australia
- Correspondence:
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Xue YP, Kao MC, Lan CY. Novel mitochondrial complex I-inhibiting peptides restrain NADH dehydrogenase activity. Sci Rep 2019; 9:13694. [PMID: 31548559 PMCID: PMC6757105 DOI: 10.1038/s41598-019-50114-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 08/29/2019] [Indexed: 12/14/2022] Open
Abstract
The emergence of drug-resistant fungal pathogens is becoming increasingly serious due to overuse of antifungals. Antimicrobial peptides have potent activity against a broad spectrum of pathogens, including fungi, and are considered a potential new class of antifungals. In this study, we examined the activities of the newly designed peptides P-113Du and P-113Tri, together with their parental peptide P-113, against the human fungal pathogen Candida albicans. The results showed that these peptides inhibit mitochondrial complex I, specifically NADH dehydrogenase, of the electron transport chain. Moreover, P-113Du and P-113Tri also block alternative NADH dehydrogenases. Currently, most inhibitors of the mitochondrial complex I are small molecules or artificially-designed antibodies. Here, we demonstrated novel functions of antimicrobial peptides in inhibiting the mitochondrial complex I of C. albicans, providing insight in the development of new antifungal agents.
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Affiliation(s)
- Yao-Peng Xue
- Institute of Molecular and Cellular Biology, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, ROC
| | - Mou-Chieh Kao
- Institute of Molecular Medicine, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, ROC. .,Department of Life Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, ROC.
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, ROC. .,Department of Life Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, ROC.
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Suchodolski J, Muraszko J, Bernat P, Krasowska A. A Crucial Role for Ergosterol in Plasma Membrane Composition, Localisation, and Activity of Cdr1p and H +-ATPase in Candida albicans. Microorganisms 2019; 7:microorganisms7100378. [PMID: 31546699 PMCID: PMC6843828 DOI: 10.3390/microorganisms7100378] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022] Open
Abstract
Candida albicans is an opportunistic fungal pathogen of humans. Treatment of C. albicans infections relies on azoles, which target the lanosterol 14α-demethylase (Erg11p) encoded by the ERG11 gene. Our results show that targeted gene disruption of ERG11 can result in resistance to ergosterol-dependent drugs (azoles and amphotericin B), auxotrophy and aerobically viable erg11Δ/Δ cells. Abnormal sterol deposition and lack of ergosterol in the erg11Δ/Δ strain leads to reduced plasma membrane (PM) fluidity, as well as dysfunction of the vacuolar and mitochondrial membranes, resulting respectively in defects in vacuole fusion and a reduced intracellular ATP level. The altered PM structure of the erg11Δ/Δ strain contributes to delocalisation of H+-ATPase and the Cdr1 efflux pump from the PM to vacuoles and, resulting in a decrease in PM potential (Δψ) and increased sensitivity to ergosterol-independent xenobiotics. This new insight into intracellular processes under Erg11p inhibition may lead to a better understanding of the indirect effects of azoles on C. albicans cells and the development of new treatment strategies for resistant infections.
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Affiliation(s)
- Jakub Suchodolski
- Department of Biotransformation, Faculty of Biotechnology, University of Wroclaw, 50-383 Wrocław, Poland.
| | - Jakub Muraszko
- Department of Biotransformation, Faculty of Biotechnology, University of Wroclaw, 50-383 Wrocław, Poland.
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237 Łódź, Banacha 12/16, Poland.
| | - Anna Krasowska
- Department of Biotransformation, Faculty of Biotechnology, University of Wroclaw, 50-383 Wrocław, Poland.
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Plasma Membrane Potential of Candida albicans Measured by Di-4-ANEPPS Fluorescence Depends on Growth Phase and Regulatory Factors. Microorganisms 2019; 7:microorganisms7040110. [PMID: 31022974 PMCID: PMC6518178 DOI: 10.3390/microorganisms7040110] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/13/2019] [Accepted: 04/22/2019] [Indexed: 11/17/2022] Open
Abstract
The potential of the plasma membrane (Δѱ) regulates the electrochemical potential between the outer and inner sides of cell membranes. The opportunistic fungal pathogen, Candida albicans, regulates the membrane potential in response to environmental conditions, as well as the physiological state of the cell. Here we demonstrate a new method for detection of cell membrane depolarization/permeabilization in C. albicans using the potentiometric zwitterionic dye di-4-ANEPPS. Di-4-ANEPPS measures the changes in the cell Δѱ depending on the phases of growth and external factors regulating Δѱ, such as potassium or calcium chlorides, amiodarone or DM-11 (inhibitor of H+-ATPase). We also demonstrated that di-4-ANEPPS is a good tool for fast measurement of the influence of amphipathic compounds on Δѱ.
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Peña A, Sánchez NS, González-López O, Calahorra M. Mechanisms involved in the inhibition of glycolysis by cyanide and antimycin A in Candida albicans and its reversal by hydrogen peroxide. A common feature in Candida species. FEMS Yeast Res 2015; 15:fov083. [PMID: 26363023 DOI: 10.1093/femsyr/fov083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2015] [Indexed: 11/14/2022] Open
Abstract
In Candida albicans, cyanide and antimycin A inhibited K(+) transport, not only with ethanol-O2 as the substrate, but also with glucose. The reason for this was that they inhibited not only respiration, but also fermentation, decreasing ATP production. Measurements of oxygen levels in cell suspensions allowed identification of the electron pathways involved. NADH fluorescence levels increased in the presence of the inhibitors, indirectly indicating lower levels of NAD(+) and so pointing to glyceraldehyde-3-phosphate dehydrogenase as the limiting step responsible for the inhibition of glycolysis, which was confirmed by the levels of glycolytic intermediaries. The cyanide effect could be reversed by hydrogen peroxide, mainly due to an activity by which H2O2 can be reduced by electrons flowing from NADH through a pathway that can be inhibited by antimycin A, and appears to be a cytochrome c peroxidase. Therefore, the inhibition of glycolysis by the respiratory inhibitors seems to be due to the decreased availability of NAD(+), resulting in a decreased activity of glyceraldehyde-3-phosphate dehydrogenase. Compartmentalization of pyridine nucleotides in favor of the mitochondria can contribute to explaining the low fermentation capacity of C. albicans. Similar results were obtained with three C. albicans strains, Candida dubliniensis and, to a lower degree, Candida parapsilosis.
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Affiliation(s)
- Antonio Peña
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, DF, 04510, México, DF, México
| | - Norma Silvia Sánchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, DF, 04510, México, DF, México
| | - Omar González-López
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, DF, 04510, México, DF, México
| | - Martha Calahorra
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, DF, 04510, México, DF, México
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Szczepaniak J, Łukaszewicz M, Krasowska A. Detection of inhibitors of Candida albicans Cdr transporters using a diS-C3(3) fluorescence. Front Microbiol 2015; 6:176. [PMID: 25806026 PMCID: PMC4353304 DOI: 10.3389/fmicb.2015.00176] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/17/2015] [Indexed: 02/06/2023] Open
Abstract
Candida albicans is a major cause of opportunistic and life-threatening, systemic fungal infections. Hence new antifungal agents, as well as new methods to treat fungal infections, are still needed. The application of inhibitors of drug-efflux pumps may increase the susceptibility of C. albicans to drugs. We developed a new fluorescence method that allows the in vivo activity evaluation of compounds inhibiting of C. albicans transporters. We show that the potentiometric dye 3,3′-dipropylthiacarbocyanine iodide diS-C3(3) is pumped out by both Cdr1 and Cdr2 transporters. The fluorescence labeling with diS-C3(3) enables a real-time observation of the activity of C. albicans Cdr1 and Cdr2 transporters. We demonstrate that enniatin A and beauvericin show different specificities toward these transporters. Enniatin A inhibits diS-C3(3) efflux by Cdr1 while beauvericin inhibits both Cdr1p and Cdr2p.
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Affiliation(s)
| | | | - Anna Krasowska
- Faculty of Biotechnology, University of Wroclaw , Wroclaw, Poland
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Robert V, Cardinali G, Casadevall A. Distribution and impact of yeast thermal tolerance permissive for mammalian infection. BMC Biol 2015; 13:18. [PMID: 25762372 PMCID: PMC4381509 DOI: 10.1186/s12915-015-0127-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/10/2015] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND From the viewpoint of fungal virulence in mammals, thermal tolerance can be defined as the ability to grow in the 35°C to 40°C range, which is essential for inhabiting these hosts. RESULTS We used archival information in a fungal collection to analyze the relationship between thermal tolerance and genetic background for over 4,289 yeast strains belonging to 1,054 species. Fungal genetic relationships were inferred from hierarchical trees based on pairwise alignments using the rRNA internal transcribed spacer and large subunit rDNA (LSU) sequences. In addition, we searched for correlations between thermal tolerance and other archival information including antifungal susceptibility, carbon sources, and fermentative capacity. Thermal tolerance for growth at mammalian temperatures was not monophyletic, with thermally tolerant species being interspersed among families that include closely related species that are not thermal tolerant. Thermal tolerance and resistance to antifungal drugs were not correlated, suggesting that these two properties evolved independently. Nevertheless, the ability to grow at higher temperatures did correlate with origin from lower geographic latitudes, capacity for fermentation and assimilation of certain carbon sources. CONCLUSIONS Thermal tolerance was significantly more common among ascomycetous than basidiomycetous yeasts, suggesting an explanation for the preponderance of ascomycetous yeasts among human pathogenic fungi. Analysis of strain maximum tolerable temperature as a function of collection time suggested that basidiomycetous yeasts are rapidly adapting to global warming. The analysis identified genera with a high prevalence of the thermal-tolerant species that could serve as sources of emerging pathogenic fungi.
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Affiliation(s)
- Vincent Robert
- Centraalbureau voor Schimmelcultures CBS, 8 Uppsalalaan, 3584CT, Utrecht, The Netherlands.
| | - Gianluigi Cardinali
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
| | - Arturo Casadevall
- Department of Microbiology and Immunology and the Division of Infectious Diseases of the Department of Medicine of the Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY, 10461, USA.
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Effects of chitosan on Candida albicans: conditions for its antifungal activity. BIOMED RESEARCH INTERNATIONAL 2013; 2013:527549. [PMID: 23844364 PMCID: PMC3703409 DOI: 10.1155/2013/527549] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 05/19/2013] [Indexed: 01/09/2023]
Abstract
The effects of low molecular weight (96.5 KDa) chitosan on the pathogenic yeast Candida albicans were studied. Low concentrations of chitosan, around 2.5 to 10 μg·mL−1 produced (a) an efflux of K+ and stimulation of extracellular acidification, (b) an inhibition of Rb+ uptake, (c) an increased transmembrane potential difference of the cells, and (d) an increased uptake of Ca2+. It is proposed that these effects are due to a decrease of the negative surface charge of the cells resulting from a strong binding of the polymer to the cells. At higher concentrations, besides the efflux of K+, it produced (a) a large efflux of phosphates and material absorbing at 260 nm, (b) a decreased uptake of Ca2+, (c) an inhibition of fermentation and respiration, and (d) the inhibition of growth. The effects depend on the medium used and the amount of cells, but in YPD high concentrations close to 1 mg·mL−1 are required to produce the disruption of the cell membrane, the efflux of protein, and the growth inhibition. Besides the findings at low chitosan concentrations, this work provides an insight of the conditions required for chitosan to act as a fungistatic or antifungal and proposes a method for the permeabilization of yeast cells.
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