51
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Richard ML, Plaine A. Comprehensive analysis of glycosylphosphatidylinositol-anchored proteins in Candida albicans. EUKARYOTIC CELL 2006; 6:119-33. [PMID: 17189485 PMCID: PMC1797948 DOI: 10.1128/ec.00297-06] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Mathias L Richard
- Laboratoire de Microbiologie et Génétique Moléculaire, INA P-G UMR-INRA1238 UMR-CNRS2585, 78850 Thiverval-Grignon, France.
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52
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Rustad TR, Choiniere JH, Howard DH, White TC. The Candida albicans mating type like locus [MTL] is not involved in chlamydospore formation. Med Mycol 2006; 44:677-81. [PMID: 17071565 DOI: 10.1080/13693780600840914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Candida albicans produces chlamydospores, which can be used as a diagnostic tool for species identification. It has been suggested that these chlamydospores are degenerate spores. If so, then their production might be linked to the mating loci, and clinical strains that are homozygous for the C. albicans mating locus MTL may be altered in chlamydospore formation, which could cause problems in diagnostics and species identification. In Saccharomyces cerevisiae diploid cells, the heterodimeric transcriptional repressor formed by the products of the mating genes MATa1 and MATalpha2 is an important regulator of sporulation. It was therefore of interest to determine if the disruptions of the MATa1 and MATalpha2 homologs in C. albicans, MTLa1 and MTLalpha2, result in inhibition of chlamydospore formation. Laboratory strains containing disruptions of either the entire MTL locus or specific genes within the locus were assayed for their ability to form chlamydospores. Clinical strains that are homozygous for one of the two MTL loci were also assayed. No change in chlamydospore formation was seen in these strains compared to the standard laboratory strain.
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Affiliation(s)
- Tige R Rustad
- Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle, WA, USA
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53
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Abstract
D-Glucosamine is an important building block of major structural components of the fungal cell wall, namely chitin, chitosan and mannoproteins. Other amino sugars, such as D-mannosamine and D-galactosamine, relatively abundant in higher eukaryotes, rarely occur in fungal cells and are actually absent from yeast and yeast-like fungi. The glucosamine-containing sugar nucleotide UDP-GlcNAc is synthesized in yeast cells in a four-step cytoplasmic pathway. This article provides a comprehensive overview of the present knowledge on the enzymes catalysing the particular steps of the pathway in Candida albicans and Saccharomyces cerevisiae, with a special emphasis put on mechanisms of the catalysed reactions, regulation of activity and perspectives for exploitation of enzymes participating in UDP-GlcNAc biosynthesis as potential targets for antifungal chemotherapy.
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Affiliation(s)
- Sławomir Milewski
- Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, Gdańsk, Poland.
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54
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Cornet M, Bidard F, Schwarz P, Da Costa G, Blanchin-Roland S, Dromer F, Gaillardin C. Deletions of endocytic components VPS28 and VPS32 affect growth at alkaline pH and virulence through both RIM101-dependent and RIM101-independent pathways in Candida albicans. Infect Immun 2006; 73:7977-87. [PMID: 16299290 PMCID: PMC1307034 DOI: 10.1128/iai.73.12.7977-7987.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ambient pH signaling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Recent evidences in the fungi Aspergillus nidulans, Saccharomyces cerevisiae, Yarrowia lipolytica, and Candida albicans suggested that components of endosomal sorting complexes required for transport (ESCRT) involved in endocytic trafficking were needed for signal transduction along the Rim pathway. In this study, we confirm these findings with C. albicans and show that Vps28p (ESCRT-I) and Vps32p/Snf7p (ESCRT-III) are required for the transcriptional regulation of known targets of the Rim pathway, such as the PHR1 and PHR2 genes encoding cell surface proteins, which are expressed at alkaline and acidic pH, respectively. We additionally show that deletion of these two VPS genes, particularly VPS32, has a more drastic effect than a RIM101 deletion on growth at alkaline pH and that this effect is only partially suppressed by expression of a constitutively active form of Rim101p. Finally, in an in vivo mouse model, both vps null mutants were significantly less virulent than a rim101 mutant, suggesting that VPS28 and VPS32 gene products affect virulence both through Rim-dependent and Rim-independent pathways.
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Affiliation(s)
- Muriel Cornet
- Laboratoire de Microbiologie et Génétique Moléculaire, INRA, CBAI, 78850 Thiverval-Grignon, France
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55
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VandenBerg AL, Ibrahim AS, Edwards JE, Toenjes KA, Johnson DI. Cdc42p GTPase regulates the budded-to-hyphal-form transition and expression of hypha-specific transcripts in Candida albicans. EUKARYOTIC CELL 2005; 3:724-34. [PMID: 15189993 PMCID: PMC420123 DOI: 10.1128/ec.3.3.724-734.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The yeast Candida albicans is a major opportunistic pathogen of immunocompromised individuals. It can grow in several distinct morphological states, including budded and hyphal forms, and the ability to make the dynamic transition between these forms is strongly correlated with virulence. Recent studies implicating the Cdc42p GTPase in hypha formation relied on cdc42 mutations that affected the mitotic functions of the protein, thereby precluding any substantive conclusions about the specific role of Cdc42p in the budded-to-hypha-form transition and virulence. Therefore, we took advantage of several Saccharomyces cerevisiae cdc42 mutants that separated Cdc42p's mitotic functions away from its role in filamentous growth. The homologous cdc42-S26I, cdc42-E100G, and cdc42-S158T mutations in C. albicans Cdc42p caused a dramatic defect in the budded-to-hypha-form transition in response to various hypha-inducing signals without affecting normal budded growth, strongly supporting the conclusion that Cdc42p has an integral function in orchestrating the morphological transition in C. albicans. In addition, the cdc42-S26I and cdc42-E100G mutants demonstrated a reduced ability to damage endothelial cells, a process that is strongly correlated to virulence. The three mutants also had reduced expression of several hypha-specific genes, including those under the regulation of the Efg1p transcription factor. These data indicate that Cdc42p-dependent signaling pathways regulate the budded-to-hypha-form transition and the expression of hypha-specific genes.
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Affiliation(s)
- Alysia L VandenBerg
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
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56
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Brand A, MacCallum DM, Brown AJP, Gow NAR, Odds FC. Ectopic expression of URA3 can influence the virulence phenotypes and proteome of Candida albicans but can be overcome by targeted reintegration of URA3 at the RPS10 locus. EUKARYOTIC CELL 2005; 3:900-9. [PMID: 15302823 PMCID: PMC500875 DOI: 10.1128/ec.3.4.900-909.2004] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Uridine auxotrophy, based on disruption of both URA3 alleles in diploid Candida albicans strain SC5314, has been widely used to select gene deletion mutants created in this fungus by "Ura-blasting" and PCR-mediated disruption. We compared wild-type URA3 expression with levels in mutant strains where URA3 was positioned either within deleted genes or at the highly expressed RPS10 locus. URA3 expression levels differed significantly and correlated with the specific activity of Ura3p, orotidine 5'-monophosphate decarboxylase. Reduced URA3 expression following integration at the GCN4 locus was associated with an attenuation of virulence. Furthermore, a comparison of the SC5314 (URA3) and CAI-4 (ura3) proteomes revealed that inactivation of URA3 caused significant changes in the levels of 14 other proteins. The protein levels of all except one were partially or fully restored by the reintegration of a single copy of URA3 at the RPS10 locus. Transcript levels of genes expressed ectopically at this locus in reconstituted heterozygous mutants also matched the levels found when the genes were expressed at their native loci. Therefore, phenotypic changes in C. albicans can be associated with the selectable marker rather than the target gene. Reintegration of URA3 at an appropriate expression locus such as RPS10 can offset most problems related to the phenotypic changes associated with gene knockout methodologies.
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Affiliation(s)
- Alexandra Brand
- School of Medical Sciences, Institute of Medical Sciences, Aberdeen AB25 2ZD, Scotland, United Kingdom
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57
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Toenjes KA, Munsee SM, Ibrahim AS, Jeffrey R, Edwards JE, Johnson DI. Small-molecule inhibitors of the budded-to-hyphal-form transition in the pathogenic yeast Candida albicans. Antimicrob Agents Chemother 2005; 49:963-72. [PMID: 15728890 PMCID: PMC549276 DOI: 10.1128/aac.49.3.963-972.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pathogenic yeast Candida albicans can exist in multiple morphological states, including budded, pseudohyphal, and true hyphal forms. The ability to convert between the budded and hyphal forms, termed the budded-to-hyphal-form transition, is important for virulence and is regulated by multiple environmental and cellular signals. To identify inhibitors of this morphological transition, a microplate-based morphological assay was developed. With this assay, the known actin-inhibiting drugs latrunculin-A and jasplakinolide were shown to inhibit the transition in a dose-dependent and reversible manner. Five novel small molecules that reversibly inhibited the transition and hyphal elongation without affecting budded growth were identified. These molecules inhibited hyphal growth induced by Spider, Lee's, M199 pH 8, and 10% serum-containing media, with two molecules having a synergistic effect. The molecules also differentially affected the hyphal form-specific gene expression of HWP1 and endocytosis without disrupting the actin cytoskeleton or septin organization. Structural derivatives of one of the molecules were more effective inhibiters than the original molecule, while other derivatives had decreased efficacies. Several of the small molecules were able to reduce C. albicans-dependent damage to endothelial cells by inhibiting the budded-to-hyphal-form transition. These studies substantiated the effectiveness of the morphological assay and identified several novel molecules that, by virtue of their ability to inhibit the budded-to-hyphal-form transition, may be exploited as starting points for effective antifungal therapeutics in the future.
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Affiliation(s)
- Kurt A Toenjes
- Department of Microbiology and Molecular Genetics, 202 Stafford Hall, 95 Carrigan Dr., University of Vermont, Burlington, VT 05405, USA
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58
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Nimrichter L, Rodrigues ML, Rodrigues EG, Travassos LR. The multitude of targets for the immune system and drug therapy in the fungal cell wall. Microbes Infect 2005; 7:789-98. [PMID: 15823515 DOI: 10.1016/j.micinf.2005.03.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 12/28/2004] [Accepted: 12/30/2004] [Indexed: 10/25/2022]
Abstract
Recent studies on fungi revealed that several cytosolic and membrane components migrate to the cell wall together with secreted proteins and biosynthetic polysaccharides to build a dynamic immunoreactive structure. New aspects of fungal cell wall assembly and biosynthesis, focusing on the potential of glycolipids, melanin, heat-shock proteins, histone and surface antigens as targets of drugs and antifungal antibodies are discussed.
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Affiliation(s)
- Leonardo Nimrichter
- Laboratório de Estudos Integrados em Bioquímica Microbiana, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco I, Ilha do Fundão, Rio de Janeiro, RJ 21941590, Brazil
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59
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Fujita M, Yoko-o T, Okamoto M, Jigami Y. GPI7 Involved in Glycosylphosphatidylinositol Biosynthesis Is Essential for Yeast Cell Separation. J Biol Chem 2004; 279:51869-79. [PMID: 15452134 DOI: 10.1074/jbc.m405232200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GPI7 is involved in adding ethanolaminephosphate to the second mannose in the biosynthesis of glycosylphosphatidylinositol (GPI) in Saccharomyces cerevisiae. We isolated gpi7 mutants, which have defects in cell separation and a daughter cell-specific growth defect at the non-permissive temperature. WSC1, RHO2, ROM2, GFA1, and CDC5 genes were isolated as multicopy suppressors of gpi7-2 mutant. Multicopy suppressors could suppress the growth defect of gpi7 mutants but not the cell separation defect. Loss of function mutations of genes involved in the Cbk1p-Ace2p pathway, which activates the expression of daughter-specific genes for cell separation after cytokinesis, bypassed the temperature-sensitive growth defect of gpi7 mutants. Furthermore, deletion of EGT2, one of the genes controlled by Ace2p and encoding a GPI-anchored protein required for cell separation, ameliorated the temperature sensitivity of the gpi7 mutant. In this mutant, Egt2p was displaced from the septal region to the cell cortex, indicating that GPI7 plays an important role in cell separation via the GPI-based modification of daughter-specific proteins in S. cerevisiae.
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Affiliation(s)
- Morihisa Fujita
- Research Center for Glycoscience, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan
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60
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Gil-Lamaignere C, Salvenmoser S, Hess R, Müller FMC. Micafungin enhances neutrophil fungicidal functions against Candida pseudohyphae. Antimicrob Agents Chemother 2004; 48:2730-2. [PMID: 15215137 PMCID: PMC434213 DOI: 10.1128/aac.48.7.2730-2732.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We evaluated the effect of the combination of micafungin and polymorphonuclear leukocytes (PMN) against hyphae of Candida albicans and Candida dubliniensis. Micafungin enhanced the PMN oxidative burst dose dependently. The combination was synergistic (C. albicans) or additive (C. dubliniensis); when PMN were pretreated with granulocyte-macrophage colony-stimulating factor, the combination was more effective.
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Affiliation(s)
- Cristina Gil-Lamaignere
- Department of Pediatrics III, Pediatric Pulmonology and Infectious Diseases, University of Heidelberg, Im Neuenheimer Feld 153, D-69120 Heidelberg, Germany.
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61
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Prigneau O, Porta A, Maresca B. Candida albicans CTN gene family is induced during macrophage infection: homology, disruption and phenotypic analysis of CTN3 gene. Fungal Genet Biol 2004; 41:783-93. [PMID: 15219562 DOI: 10.1016/j.fgb.2004.04.001] [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: 11/21/2003] [Accepted: 04/06/2004] [Indexed: 11/22/2022]
Abstract
We have isolated a Candida albicans gene, coding for a putative peroxisomal carnitine acetyl transferase (CTN) protein, which is up-regulated during macrophage infection. In the present study, we describe the disruption of CTN3 gene (previously called CAT3) to gain insight into its potential role during infection. The ability of disrupted Candida mutants to filament was affected by several solid media. Northern blot analysis revealed that CTN3 gene may be involved not only in conditions of cell starvation but also during the process of germination. In agreement with the putative peroxisomal localization of the corresponding protein, we observed a strong glucose repression of CTN3 gene and, on the contrary, high level of transcription by carbon sources that induce the formation of peroxisomal proteins. Furthermore, we showed the existence of two additional C. albicans CTN encoding sequences, which are also induced during macrophage infection.
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Affiliation(s)
- Odile Prigneau
- Laboratory of Molecular Fungal Pathogenesis, Institute of Genetics and Biophysics Buzzati Traverso, Via Marconi, 12-80125 Naples, Italy
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62
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Garcerá A, Martínez AI, Castillo L, Elorza MV, Sentandreu R, Valentín E. Identification and study of a Candida albicans protein homologous to Saccharomyces cerevisiae Ssr1p, an internal cell-wall protein. MICROBIOLOGY (READING, ENGLAND) 2003; 149:2137-2145. [PMID: 12904553 DOI: 10.1099/mic.0.26301-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
After screening of a Candida albicans genome database, the product of an ORF (IPF 3054) that has 62 % homology with Saccharomyces cerevisiae Ssr1p, an internal cell-wall protein, was identified and named CaSsr1p. The deduced amino acid sequence shows that CaSsr1p contains an N-terminal hydrophobic signal peptide, is rich in Ser and Thr amino acids and has a potential glycosylphosphatidylinositol-attachment signal. CaSsr1p is released following degradation of isolated cell walls by zymolyase (mainly a 1,3-beta-glucanase) and therefore seems to be covalently linked to the beta-glucan of the cell walls. Both disruption and overexpression of the CaSSR1 gene caused an increased sensitivity to calcofluor white, Congo red and zymolyase digestion. These results suggest that CaSsr1p has a structural role associated with the cell-wall beta-glucan.
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Affiliation(s)
- Ana Garcerá
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
| | - Ana Isabel Martínez
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
| | - Luis Castillo
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
| | - M Victoria Elorza
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
| | - Rafael Sentandreu
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
| | - Eulogio Valentín
- Departamento de Microbiología y Ecología, Facultad de Farmacia, Universidad de Valencia, Avda. Vicente Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain
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63
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Romani L, Bistoni F, Puccetti P. Adaptation of Candida albicans to the host environment: the role of morphogenesis in virulence and survival in mammalian hosts. Curr Opin Microbiol 2003; 6:338-43. [PMID: 12941401 DOI: 10.1016/s1369-5274(03)00081-x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although morphological flexibility could be a key contributor to fungal virulence, no molecular data has unambiguously established fungal morphogenesis as a virulence factor for Candida albicans, nor can specific forms of Candida be regarded as absolutely indicative of saprophytism or infection at a given site on the host. The fitness of the fungus in vivo probably reflects its adaptation to the variety of microenvironments in which this opportunist must survive.
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Affiliation(s)
- Luigina Romani
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Via del Giochetto, 06122 Perugia, Italy.
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64
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Spreghini E, Davis DA, Subaran R, Kim M, Mitchell AP. Roles of Candida albicans Dfg5p and Dcw1p cell surface proteins in growth and hypha formation. EUKARYOTIC CELL 2003; 2:746-55. [PMID: 12912894 PMCID: PMC178370 DOI: 10.1128/ec.2.4.746-755.2003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Candida albicans cell wall participates in both growth and morphological transitions between yeast and hyphae. Our studies here focus on Dfg5p and Dcw1p, two similar proteins with features of glycosylphosphatidylinositol-linked cell surface proteins. Mutants lacking Dfg5p are defective in alkaline pH-induced hypha formation; mutants lacking Dcw1p have no detected hypha formation defect. Both homozygote-triplication tests and conditional expression strategies indicate that dfg5 and dcw1 mutations are synthetically lethal. Therefore, Dfg5p and Dcw1p share a function required for growth. Epitope-tagged Dfg5p, created through an insertional mutagenesis strategy, is found in cell membrane and cell wall extract fractions, and endoglycosidase H digestion shows that Dfg5p undergoes N-linked mannosylation. Surprisingly, Dfg5p is required for expression of the hypha-specific gene HWP1 in alkaline media. Because Dfg5p is a cell surface protein, it is poised to generate or transmit an external signal required for the program of hypha-specific gene expression.
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Affiliation(s)
- Elisabetta Spreghini
- Department of Microbiology and Institute of Cancer Research, Columbia University, New York, New York 10032, USA
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65
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Rogers PD, Barker KS. Evaluation of differential gene expression in fluconazole-susceptible and -resistant isolates of Candida albicans by cDNA microarray analysis. Antimicrob Agents Chemother 2002; 46:3412-7. [PMID: 12384344 PMCID: PMC128735 DOI: 10.1128/aac.46.11.3412-3417.2002] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The opportunistic fungal pathogen Candida albicans is the major causative agent of oropharyngeal candidiasis (OPC) in AIDS. The development of azoles, such as fluconazole, for the treatment of OPC has proven effective except in cases where C. albicans develops resistance to fluconazole during the course of treatment. In the present study, we used microarray technology to examine differences in gene expression from a fluconazole-susceptible and a fluconazole-resistant well-characterized, clinically obtained matched set of C. albicans isolates to identify genes which are differentially expressed in association with azole resistance. Among genes found to be differentially expressed were those involved in amino acid and carbohydrate metabolism; cell stress, cell wall maintenance; lipid, fatty acid, and sterol metabolism; and small molecule transport. In addition to CDR1, which has previously been demonstrated to be associated with azole resistance, the drug resistance gene RTA3, the ergosterol biosynthesis gene ERG2, and the cell stress genes CRD2, GPX1, and IFD5 were found to be upregulated. Several genes, such as the mitochondrial aldehyde dehydrogenase gene ALD5, the glycosylphosphatidylinositol synthesis gene GPI1, and the iron transport genes FET34 and FTR2 were found to be downregulated. Further study of these differentially regulated genes is warranted to evaluate how they may be involved in azole resistance. In addition to these novel findings, we demonstrate the utility of microarray analysis for studying the molecular mechanisms of drug resistance in pathogenic organisms.
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Affiliation(s)
- P David Rogers
- Departments of Clinical Pharmacy. Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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66
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Current awareness on yeast. Yeast 2002; 19:1183-90. [PMID: 12371408 DOI: 10.1002/yea.828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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67
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Richard M, de Groot P, Courtin O, Poulain D, Klis F, Gaillardin C. GPI7 affects cell-wall protein anchorage in Saccharomyces cerevisiae and Candida albicans. MICROBIOLOGY (READING, ENGLAND) 2002; 148:2125-2133. [PMID: 12101300 DOI: 10.1099/00221287-148-7-2125] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glycosylphosphatidylinositol (GPI)-anchoring represents a mechanism for attaching proteins to the cell surface of all eukaryotic cells. Two localizations of GPI proteins have been observed in the yeasts Saccharomyces cerevisiae and Candida albicans: plasma membrane and cell wall. The signals and the mechanisms involved in this differential targeting are presently not well understood. Here several cell-wall-related phenotypes of a gpi7/las21 deletion are described, where GPI7/LAS21 encodes a GPI-anchor-modifying activity. In both organisms, the structure and composition of the cell wall was modified, with a clear increase in chitin deposition. Cell-wall-targeted proteins accumulated in the growth medium, whereas the protein content of the cell wall decreased significantly, suggesting inefficiency of the covalent linkage. The level of plasma-membrane-targeted GPI proteins was not affected. Sequence analyses revealed that gene families involved in the addition of phosphoethanolamines to the core GPI anchor are highly conserved between eukaryotes, with the exception of the Gpi7 family which seems to be fungus-specific. These data are compatible with the notion that the phosphoethanolamine added by Gpi7 protein to the GPI anchor is a key factor in the covalent linkage of cell-wall proteins to fungal cell-wall components.
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Affiliation(s)
- Mathias Richard
- Laboratoire de Génétique Moléculaire et Cellulaire, Institut National Agronomique Paris-Grignon, UMR-INRA216, URA-CNRS1925, BP01, 78850 Thiverval-Grignon, France1
| | - Piet de Groot
- Fungal Research Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands2
| | - Olivier Courtin
- Aventis Pharma, 102 route de Noisy, 93235 Romainville cedex, France3
| | - Daniel Poulain
- Laboratoire de Mycologie Fondamentale et Appliquée, INSERM EPI 9915, Université de Lille II, Faculté de Médecine H. Warembourg, Pôle Recherche, Place Verdun, 59037 Lille Cedex, France4
| | - Frans Klis
- Fungal Research Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands2
| | - Claude Gaillardin
- Laboratoire de Génétique Moléculaire et Cellulaire, Institut National Agronomique Paris-Grignon, UMR-INRA216, URA-CNRS1925, BP01, 78850 Thiverval-Grignon, France1
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