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Cunha AF, Sousa MV, Silva SP, JesuÍno RSA, Soares CMA, Felipe MSS. Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins in Paracoccidioides brasiliensis. Med Mycol 2008. [DOI: 10.1111/j.1365-280x.1999.00211.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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2
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Pedreño Y, González-Párraga P, Martínez-Esparza M, Sentandreu R, Valentín E, Argüelles JC. Disruption of the Candida albicans ATC1 gene encoding a cell-linked acid trehalase decreases hypha formation and infectivity without affecting resistance to oxidative stress. MICROBIOLOGY-SGM 2007; 153:1372-1381. [PMID: 17464051 DOI: 10.1099/mic.0.2006/003921-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Candida albicans, the ATC1 gene, encoding a cell wall-associated acid trehalase, has been considered as a potentially interesting target in the search for new antifungal compounds. A phenotypic characterization of the double disruptant atc1Delta/atc1Delta mutant showed that it was unable to grow on exogenous trehalose as sole carbon source. Unlike actively growing cells from the parental strain (CAI4), the atc1Delta null mutant displayed higher resistance to environmental insults, such as heat shock (42 degrees C) or saline exposure (0.5 M NaCl), and to both mild and severe oxidative stress (5 and 50 mM H(2)O(2)), which are relevant during in vivo infections. Parallel measurements of intracellular trehalose and trehalose-metabolizing enzymes revealed that significant amounts of the disaccharide were stored in response to thermal and oxidative challenge in the two cell types. The antioxidant activities of catalase and glutathione reductase were triggered by moderate oxidative exposure (5 mM H(2)O(2)), whereas superoxide dismutase was inhibited dramatically by H(2)O(2), where a more marked decrease was observed in atc1Delta cells. In turn, the atc1Delta mutant exhibited a decreased capacity of hypha and pseudohypha formation tested in different media. Finally, the homozygous null mutant in a mouse model of systemic candidiasis displayed strongly reduced pathogenicity compared with parental or heterozygous strains. These results suggest not only a novel role for the ATC1 gene in dimorphism and infectivity, but also that an interconnection between stress resistance, dimorphic conversion and virulence in C. albicans may be reconsidered. They also support the hypothesis that Atc1p is not involved in the physiological hydrolysis of endogenous trehalose.
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Affiliation(s)
- Yolanda Pedreño
- Departamento de Microbiología y Ecología, Universidad de Valencia, E-46100 Burjassot, Valencia, Spain
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, E-30071 Murcia, Spain
| | - Pilar González-Párraga
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, E-30071 Murcia, Spain
| | - María Martínez-Esparza
- Departamento de Bioquímica y Biología Molecular B e Inmunología, Universidad de Murcia, E-30071 Murcia, Spain
| | - Rafael Sentandreu
- Departamento de Microbiología y Ecología, Universidad de Valencia, E-46100 Burjassot, Valencia, Spain
| | - Eulogio Valentín
- Departamento de Microbiología y Ecología, Universidad de Valencia, E-46100 Burjassot, Valencia, Spain
| | - Juan-Carlos Argüelles
- Área de Microbiología, Facultad de Biología, Universidad de Murcia, E-30071 Murcia, Spain
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Borelli C, Ruge E, Schaller M, Monod M, Korting HC, Huber R, Maskos K. The crystal structure of the secreted aspartic proteinase 3 from Candida albicans and its complex with pepstatin A. Proteins 2007; 68:738-48. [PMID: 17510964 DOI: 10.1002/prot.21425] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The family of secreted aspartic proteinases (Sap) encoded by 10 SAP genes is an important virulence factor during Candida albicans (C. albicans) infections. Antagonists to Saps could be envisioned to help prevent or treat candidosis in immunocompromised patients. The knowledge of several Sap structures is crucial for inhibitor design; only the structure of Sap2 is known. We report the 1.9 and 2.2 A resolution X-ray crystal structures of Sap3 in a stable complex with pepstatin A and in the absence of an inhibitor, shedding further light on the enzyme inhibitor binding. Inhibitor binding causes active site closure by the movement of a flap segment. Comparison of the structures of Sap3 and Sap2 identifies elements responsible for the specificity of each isoenzyme.
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Affiliation(s)
- Claudia Borelli
- Department of Dermatology and Allergy, Ludwig Maximilian University of Munich, Frauenlobstr. 9-11, 80337 Munich, Germany.
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Kraus PR, Boily MJ, Giles SS, Stajich JE, Allen A, Cox GM, Dietrich FS, Perfect JR, Heitman J. Identification of Cryptococcus neoformans temperature-regulated genes with a genomic-DNA microarray. EUKARYOTIC CELL 2005; 3:1249-60. [PMID: 15470254 PMCID: PMC522612 DOI: 10.1128/ec.3.5.1249-1260.2004] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability to survive and proliferate at 37 degrees C is an essential virulence attribute of pathogenic microorganisms. A partial-genome microarray was used to profile gene expression in the human-pathogenic fungus Cryptococcus neoformans during growth at 37 degrees C. Genes with orthologs involved in stress responses were induced during growth at 37 degrees C, suggesting that a conserved transcriptional program is used by C. neoformans to alter gene expression during stressful conditions. A gene encoding the transcription factor homolog Mga2 was induced at 37 degrees C and found to be important for high-temperature growth. Genes encoding fatty acid biosynthetic enzymes were identified as potential targets of Mga2, suggesting that membrane remodeling is an important component of adaptation to high growth temperatures. mga2Delta mutants were extremely sensitive to the ergosterol synthesis inhibitor fluconazole, indicating a coordination of the synthesis of membrane component precursors. Unexpectedly, genes involved in amino acid and pyrimidine biosynthesis were repressed at 37 degrees C, but components of these pathways were found to be required for high-temperature growth. Our findings demonstrate the utility of even partial-genome microarrays for delineating regulatory cascades that contribute to microbial pathogenesis.
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Affiliation(s)
- Peter R Kraus
- Department of Molecular Genetics and Microbiology, 322 CARL Building, Box 3546, Research Dr., Duke University Medical Center, Durham, NC 27710, USA
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González-Párraga P, Marín FR, Argüelles JC, Hernández JA. Correlation between the intracellular content of glutathione and the formation of germ-tubes induced by human serum in Candida albicans. Biochim Biophys Acta Gen Subj 2005; 1722:324-30. [PMID: 15777624 DOI: 10.1016/j.bbagen.2005.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 12/02/2004] [Accepted: 01/04/2005] [Indexed: 10/25/2022]
Abstract
The physiological role of the tripeptide glutathione (GSH) and its oxidized form (GSSG) was investigated during the initial steps of dimorphism (formation of germ-tubes), which is induced by human serum in exponential yeast-like cells (blastoconidia) of the Candida albicans strain CAI-4 (wild type) and its congenic tps1/tps1 mutant, deficient in trehalose synthesis. The content of glutathione, measured both as GSH and the ratio GSH/GSSG, underwent a moderate drop in parallel with the induction of a significant degree of germ-tube emergence. Whereas the supply of exogenous glutathione did not affect the degree of dimorphic transition, depletion of intracellular glutathione by addition of 1-chloro-2,4 dinitrobenzene (CDNB) caused a clear reduction in the percentage of hyphae formation; although this effect must be due to the severe cell mortality produced by CDNB. Simultaneous measurements of GSH-metabolizing activities revealed a moderate decrease of glutathione reductase concomitant with the activation of glutathione peroxidase. In turn, catalase activity did not show noticeable changes. The putative correlation between the redox status of glutathione and the dimorphic conversion in C. albicans is discussed.
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Affiliation(s)
- Pilar González-Párraga
- Area de Microbiología, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, E-30071 Murcia, Spain
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Wartmann T, Stephan UW, Bube I, Böer E, Melzer M, Manteuffel R, Stoltenburg R, Guengerich L, Gellissen G, Kunze G. Post-translational modifications of the AFET3 gene product: a component of the iron transport system in budding cells and mycelia of the yeast Arxula adeninivorans. Yeast 2002; 19:849-62. [PMID: 12112239 DOI: 10.1002/yea.880] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The yeast Arxula adeninivorans is characterized by a temperature-dependent dimorphism. A. adeninivorans grows as budding cells at temperatures up to 42 degrees C, but forms mycelia at higher temperatures. A strong correlation exists between morphological status and iron uptake, achieved by two transport systems that differ in iron affinity. In the presence of high Fe(II) concentrations (>2 microm), budding cells accumulate iron concentrations up to seven-fold higher than those observed in mycelia, while at low Fe(II) concentrations (<2 microm), both cell types accumulate similar amounts of iron. The copper-dependent Fe(II) oxidase Afet3p, composed of 615 amino acids, is a component of the high-affinity iron transport system. This protein shares a high degree of homology with other yeast iron transport proteins, namely Fet3p of Saccharomyces cerevisiae, Cafet3p of Candida albicans and Pfet3p of Pichia pastoris. Expression of the AFET3 gene is found to be strongly dependent on iron concentration but independent of the morphological stage; however, cell morphology was found to influence post-translational modifications of the gene product. O-glycosylation was observed in budding cells only, whereas N-glycosylation occurred in both cell types. The N-glycosylated 103 kDa glycoprotein matures into the 108.5 kDa form, further characterized by serine phosphorylation. Both N-glycosylation and phosphorylation occur at low iron concentrations (< or =5 microm). The mature Afet3p of 108.5 kDa is uniformly distributed within the plasma membrane in cells of both morphological stages.
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Affiliation(s)
- Thomas Wartmann
- Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany.
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Jürgensen CW, Jacobsen NR, Emri T, Eriksen SH, Pócsi I. Glutathione metabolism and dimorphism in Aureobasidium pullulans. J Basic Microbiol 2002; 41:131-7. [PMID: 11441460 DOI: 10.1002/1521-4028(200105)41:2<131::aid-jobm131>3.0.co;2-#] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Yeast<-->mycelium morphological transitions of Aureobasidium pullulans are influenced by numerous environmental factors. In general, changes in the glutathione (GSH) metabolism of dimorphic fungi may lead to alterations in the reduced thiol status of the cells that are hypothesised to initialise morphological transitions. In accordance with this hypothesis, the specific GSH levels found in A. pullulans yeast cells were always significantly higher than those in mycelia. One the other hand, there was no significant difference between the GSH/GSSG redox status of the cells with either yeast or mycelial morphology. The cascade of events leading to morphological transitions was therefore unlikely to proceed via redox modulation of protein thiols. Although there were morphology-dependent differences in the specific activities of some GSH metabolic enzymes, e.g. glutathione reductase (GR), gamma-glutamyltranspeptidase (gamma GT), glucose-6-phosphate dehydrogenase (G6PD), they were not satisfactory to explain the observed alterations in the intracellular GSH levels. It is noteworthy that very similar specific gamma GT and G6PD activities were found in cells separated from mixed morphology cultures independently of the actual cell morphology. On the other hand, the specific gamma GT and G6PD activities of A. pullulans cells sharing the same morphology but separated from pure and mixed morphology cultures showed marked differences.
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Affiliation(s)
- C W Jürgensen
- Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, P.O. Box 63, H-4010 Debrecen, Hungary
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Cunha AF, Sousa MV, Silva SP, JesuIno RSA, Soares CMA, Felipe MSS. Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins in Paracoccidioides brasiliensis. Med Mycol 1999. [DOI: 10.1046/j.1365-280x.1999.00211.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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9
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Cunha A, Sousa M, Silva S, Jesuíno R, Soares C, Felipe M. Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins inParacoccidioides brasiliensis. Med Mycol 1999. [DOI: 10.1080/02681219980000181] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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10
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Ishii N, Yamamoto M, Lahm HW, Lizumi S, Yoshihara F, Nakayama H, Arisawa M, Aoki Y. A DNA-binding protein from Candida albicans that binds to the RPG box of Saccharomyces cerevisiae and the telomeric repeat sequence of C. albicans. MICROBIOLOGY (READING, ENGLAND) 1997; 143 ( Pt 2):417-427. [PMID: 9043119 DOI: 10.1099/00221287-143-2-417] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Electromobility shift assays with a DNA probe containing the Saccharomyces cerevisiae ENO1 RPG box identified a specific DNA-binding protein in total protein extracts of Candida albicans. The protein, named Rbf1p (RPG-box-binding protein 1), bound to other S. cerevisiae RPG boxes, although the nucleotide recognition profile was not completely the same as that of S. cerevisiae Rap 1p (repressor-activator protein 1), an RPG-box-binding protein. The repetitive sequence of the C. albicans chromosomal telomere also competed with RPG-box binding to Rbf1p. For further analysis, we purified Rbf1p 57,600-fold from C. albicans total protein extracts, raised mAbs against the purified protein and immunologically cloned the gene, whose ORF specified a protein of 527 aa. The bacterially expressed protein showed RPG-box-binding activity with the same profile as that of the purified one. The Rbf1p, containing two glutamine-rich regions that are found in many transcription factors, showed transcriptional activation capability in S. cerevisiae and was predominantly observed in nuclei. These results suggest that Rbf1p is a transcription factor with telomere-binding activity in C. albicans.
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Affiliation(s)
- Nobuya Ishii
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Mutumi Yamamoto
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Hans-Werner Lahm
- Department of PRPB, F. Hoffman-La Roche AG, Postfach 4070, Basel, Switzerland
| | - Shinnji Lizumi
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Fumie Yoshihara
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Hironobu Nakayama
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Mikio Arisawa
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
| | - Yuhko Aoki
- Department of Mycology, Nippon Roche Research Center, Kajiwara 200, Kamakura, Kanagawa-Prefecture, Japan
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