Integrative, multifunctional plasmids for hypha-specific or constitutive expression of green fluorescent protein in Candida albicans

Microbiology ◽  
2003 ◽  
Vol 149 (10) ◽  
pp. 2977-2986 ◽  
Author(s):  
Janet F. Staab ◽  
Yong-Sun Bahn ◽  
Paula Sundstrom
Keyword(s):  
Candida Albicans ◽  
Green Fluorescent Protein ◽  
Germ Tube ◽  
Fluorescent Protein ◽  
Constitutive Expression ◽  
Tube Formation ◽  
Developmental Expression ◽  
Specific Gene ◽  
Expression Of Genes ◽  
Green Fluorescent

The authors have engineered plasmid constructs for developmental and constitutive expression of yeast-enhanced green fluorescent protein (yEGFP3) in Candida albicans. The promoter for the hyphae-specific gene Hyphal Wall Protein 1 (HWP1) conferred developmental expression of yEGFP3 in germ tubes and hyphae but not in yeasts or pseudohyphae when targeted to the ENO1 (enolase) locus in single copy. The pHWP1GFP3 construct allows for the easy visualization of HWP1 promoter activity in individual cells expressing true hyphae without having to prepare RNA for analysis. Constitutive expression of yEGFP was seen in all cell morphologies when the HWP1 promoter was replaced with the ENO1 promoter region. The use of the plasmids for expression of genes other than yEGFP3 was examined by substituting the putative C. albicans BCY1 (SRA1) gene, a component of the cAMP signalling pathway involved in yeast to hyphae transitions, for yEGFP3. Strains overexpressing BCY1 from the ENO1 promoter were inhibited in germ tube formation and filamentation in both liquid and solid media, a phenotype consistent with keeping protein kinase A in its inactive form by association with Bcy1p. The plasmids are suitable for studies of germ tube induction or assessing germ tube formation by measuring yEGFP3 expression, for inducible expression of genes concomitant with germ tube formation by the HWP1 promoter, for constitutive expression of genes by the ENO1 promoter, and for expressing yEGFP3 using a promoter of choice.

Green fluorescent protein in Candida albicans-related studies

2010 ◽  
Vol 30 (5) ◽  
pp. 541-544
Author(s):  
Hui LU ◽  
Ying-ying CAO ◽  
Yan WANG ◽  
Ping-hui GAO ◽  
Yong-bing CAO ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Green Fluorescent

scholarly journals Fructose Induces Fluconazole Resistance in Candida albicans through Activation of Mdr1 and Cdr1 Transporters

2021 ◽  
Vol 22 (4) ◽  
pp. 2127
Author(s):  
Jakub Suchodolski ◽  
Anna Krasowska
Keyword(s):  
Candida Albicans ◽  
Multidrug Resistance ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
De Novo ◽  
Pathogenic Fungus ◽  
Serum Levels ◽  
Efflux Transporters ◽  
Fluconazole Resistance ◽  
Green Fluorescent

Candida albicans is a pathogenic fungus that is increasingly developing multidrug resistance (MDR), including resistance to azole drugs such as fluconazole (FLC). This is partially a result of the increased synthesis of membrane efflux transporters Cdr1p, Cdr2p, and Mdr1p. Although all these proteins can export FLC, only Cdr1p is expressed constitutively. In this study, the effect of elevated fructose, as a carbon source, on the MDR was evaluated. It was shown that fructose, elevated in the serum of diabetics, promotes FLC resistance. Using C. albicans strains with green fluorescent protein (GFP) tagged MDR transporters, it was determined that the FLC-resistance phenotype occurs as a result of Mdr1p activation and via the increased induction of higher Cdr1p levels. It was observed that fructose-grown C. albicans cells displayed a high efflux activity of both transporters as opposed to glucose-grown cells, which synthesize Cdr1p but not Mdr1p. Additionally, it was concluded that elevated fructose serum levels induce the de novo production of Mdr1p after 60 min. In combination with glucose, however, fructose induces Mdr1p production as soon as after 30 min. It is proposed that fructose may be one of the biochemical factors responsible for Mdr1p production in C. albicans cells.

scholarly journals A Photostable Green Fluorescent Protein Variant for Analysis of Protein Localization in Candida albicans

2009 ◽  
Vol 9 (1) ◽  
pp. 224-226 ◽  
Author(s):  
Chengda Zhang ◽  
James B. Konopka
Keyword(s):  
Candida Albicans ◽  
Green Fluorescent Protein ◽  
Codon Usage ◽  
Signal Intensity ◽  
Fluorescent Protein ◽  
Protein Localization ◽  
Protein Variant ◽  
Green Fluorescent ◽  
Green Fluorescent Protein Variant

ABSTRACT Fusions to the green fluorescent protein (GFP) are an effective way to monitor protein localization. However, altered codon usage in Candida species has delayed implementation of new variants. Examination of three new GFP variants in Candida albicans showed that one has higher signal intensity and increased resistance to photobleaching.

Laser-induced gene expression in specific cells of transgenic zebrafish

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1953-1960 ◽  
Author(s):  
M.C. Halloran ◽  
M. Sato-Maeda ◽  
J.T. Warren ◽  
F. Su ◽  
Z. Lele ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Green Fluorescent Protein Gene ◽  
Transgenic Zebrafish ◽  
Hsp70 Promoter ◽  
Expression Of Genes ◽  
Transgenic Lines ◽  
Transgenic Embryos ◽  
Green Fluorescent

Over the past few years, a number of studies have described the generation of transgenic lines of zebrafish in which expression of reporters was driven by a variety of promoters. These lines opened up the real possibility that transgenics could be used to complement the genetic analysis of zebrafish development. Transgenic lines in which the expression of genes can be regulated both in space and time would be especially useful. Therefore, we have cloned the zebrafish promoter for the inducible hsp70 gene and made stable transgenic lines of zebrafish that express the reporter green fluorescent protein gene under the control of a hsp70 promoter. At normal temperatures, green fluorescent protein is not detectable in transgenic embryos with the exception of the lens, but is robustly expressed throughout the embryo following an increase in ambient temperature. Furthermore, we have taken advantage of the accessibility and optical clarity of the embryos to express green fluorescent protein in individual cells by focussing a sublethal laser microbeam onto them. The targeted cells appear to develop normally: cells migrate normally, neurons project axons that follow normal pathways, and progenitor cells divide and give rise to normal progeny cells. By generating other transgenic lines in which the hsp70 promoter regulates genes of interest, it should be possible to examine the in vivo activity of the gene products by laser-inducing specific cells to express them in zebrafish embryos. As a first test, we laser-induced single muscle cells to make zebrafish Sema3A1, a semaphorin that is repulsive for specific growth cones, in a hsp70-sema3A1 transgenic line of zebrafish and found that extension by the motor axons was retarded by the induced muscle.

ALS3 and ALS8 represent a single locus that encodes a Candida albicans adhesin; functional comparisons between Als3p and Als1p

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2415-2428 ◽  
Author(s):  
Xiaomin Zhao ◽  
Soon-Hwan Oh ◽  
Georgina Cheng ◽  
Clayton B. Green ◽  
Jennifer A. Nuessen ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Fluorescent Protein ◽  
Mutational Analysis ◽  
Oral Candidiasis ◽  
Tube Formation ◽  
Single Locus ◽  
Wild Type ◽  
Mutant Strains ◽  
Encoded Proteins

The ALS (agglutinin-like sequence) gene family of Candida albicans encodes eight cell-surface glycoproteins, some of which are involved in adherence to host surfaces. A mutational analysis of each ALS gene is currently being performed to deduce the functions of the encoded proteins and to better understand the role of these proteins in C. albicans biology and pathogenesis. This paper describes construction of an als3/als3 mutant and comparison of its phenotype to an als1/als1 strain. Efforts to disrupt ALS3 indicated that the gene could be deleted in two transformation steps, suggesting that the gene is encoded by a single locus and that the ALS3-like locus, ALS8, does not exist. Strains lacking ALS3 or ALS1 did not exhibit a defect in germ tube formation when grown in RPMI 1640 medium, but the als1/als1 mutant formed significantly fewer germ tubes in Lee medium. Analysis of ALS3 and ALS1 promoter activity using green fluorescent protein (GFP) reporter strains and flow cytometry showed that when cells are placed into medium that promotes germ tube formation, ALS1 is transcribed prior to ALS3. Comparison of the mutant strains in adhesion assays showed that the als3/als3 strain was defective in adhesion to both human umbilical vein endothelial cells (HUVEC) and buccal epithelial cells (BEC), but not to fibronectin-coated plastic plates. In contrast, the als1/als1 strain showed decreased adherence to HUVEC, but adherence to BEC and fibronectin were the same as wild-type controls. Inoculation of the buccal reconstituted human epithelium (RHE) model of oral candidiasis with the mutant strains showed nearly a total lack of adhesion and epithelial destruction by the als3/als3 mutant while the als1/als1 strain showed only a slightly reduced degree of epithelial destruction compared to the wild-type control. Adhesion data presented here suggest that, in the assays performed, loss of Als3p affects C. albicans adhesion more than loss of Als1p. Collectively, these results demonstrate functional similarities and differences between Als1p and Als3p, and suggest the potential for more complex interrelationships between the ALS genes and their encoded proteins.

Use of Green Fluorescent Protein Expressing Salmonella Stanley To Investigate Survival, Spatial Location, and Control on Alfalfa Sprouts

2001 ◽  
Vol 64 (12) ◽  
pp. 1891-1898 ◽  
Author(s):  
MEGHA GANDHI ◽  
SHERENE GOLDING ◽  
SIMA YARON ◽  
KARL R. MATTHEWS
Keyword(s):  
Green Fluorescent Protein ◽  
Laser Scanning ◽  
Fluorescent Protein ◽  
Plasmid Stability ◽  
Constitutive Expression ◽  
Epifluorescence Microscopy ◽  
Initial Population ◽  
Alfalfa Sprouts ◽  
Green Fluorescent ◽  
Alfalfa Seeds

Laser scanning confocal microscopy (LSCM) was used to observe the interaction of Salmonella Stanley with alfalfa sprouts. The green fluorescent protein (gfp) gene was integrated into the chromosome of Salmonella Stanley for constitutive expression, thereby eliminating problems of plasmid stability and loss of signal. Alfalfa seeds were inoculated by immersion in a suspension of Salmonella Stanley (ca. 107 CFU/ml) for 5 min at 22°C. Epifluorescence microscopy demonstrated the presence of target bacteria on the surface of sprouts. LSCM demonstrated bacteria present at a depth of 12μm within intact sprout tissue. An initial population of ca. 104 CFU/g seed increased to 7.0 log CFU/g during a 24-h germination period and then decreased to 4.9 log CFU/g during a 144-h sprouting period. Populations of Salmonella Stanley on alfalfa seeds decreased from 5.2 to 4.1 log CFU/g and from 5.2 to 2.8 log CFU/g for seeds stored 60 days at 5 and 22°C, respectively. The efficacy of 100, 200, 500, or 2,000 ppm chlorine in killing Salmonella Stanley associated with sprouts was determined. Treatment of sprouts in 2,000 ppm chlorine for 2 or 5 min caused a significant reduction in populations of Salmonella Stanley. Influence of storage on Salmonella Stanley populations was investigated by storing sprouts 4 days at 4°C. The initial population (7.76 log CFU/g) of Salmonella Stanley on mature sprouts decreased (7.67 log CFU/g) only slightly. Cross-contamination during harvest was investigated by harvesting contaminated sprouts, then directly harvesting noncontaminated sprouts. This process resulted in the transfer of ca. 105 CFU/g Salmonella Stanley to the noncontaminated sprouts.

scholarly journals Use of Green Fluorescent Protein and Reverse Transcription-PCR To Monitor Candida albicans Agglutinin-Like Sequence Gene Expression in a Murine Model of Disseminated Candidiasis

2005 ◽  
Vol 73 (3) ◽  
pp. 1852-1855 ◽  
Author(s):  
Clayton B. Green ◽  
Xiaomin Zhao ◽  
Lois L. Hoyer
Keyword(s):  
Candida Albicans ◽  
Green Fluorescent Protein ◽  
Reverse Transcription ◽  
Fluorescent Protein ◽  
Rt Pcr ◽  
Disseminated Candidiasis ◽  
Reverse Transcription Pcr ◽  
Gfp Reporter ◽  
Reporter Strains ◽  
Green Fluorescent

ABSTRACT Candida albicans PALS-green fluorescent protein (GFP) reporter strains were inoculated into mice in a disseminated candidiasis model, and GFP production was monitored by immunohistochemistry and reverse transcription-PCR (RT-PCR). GFP production from the ALS1 and ALS3 promoters was detected immunohistochemically. ALS1, ALS2, ALS3, ALS4, and ALS9 transcription was detected by RT-PCR, further identifying ALS genes expressed in this model.

scholarly journals Candida albicans Sfl1 Suppresses Flocculation and Filamentation

2007 ◽  
Vol 6 (10) ◽  
pp. 1736-1744 ◽  
Author(s):  
Janine Bauer ◽  
Jürgen Wendland
Keyword(s):  
Candida Albicans ◽  
Fluorescent Protein ◽  
Tube Formation ◽  
Negative Regulator ◽  
Yeast Cells ◽  
Transcriptional Repressors ◽  
Reverse Transcription Pcr ◽  
Green Fluorescent ◽  
Mutant Phenotypes

ABSTRACT Hyphal morphogenesis in Candida albicans is regulated by multiple pathways which act by either inducing or repressing filamentation. Most notably, Tup1, Nrg1, and Rfg1 are transcriptional repressors, while Efg1, Flo8, Cph1, and Czf1 can induce filamentation. Here, we present the functional analysis of CaSFL1, which encodes the C. albicans homolog of the Saccharomyces cerevisiae SFL1 (suppressor of flocculation) gene. Deletion of CaSFL1 results in flocculation (i.e., the formation of clumps) of yeast cells, which is most pronounced in minimal medium. The flocs contained hyphae already under noninducing conditions, and filamentation could be enhanced with hypha-inducing cues at 37°C. Expression of SFL1 in a heterozygous mutant under the control of the CaMET3 promoter was shown to complement these defects and allowed switching between wild-type and mutant phenotypes. Interestingly, increased expression of SFL1 using a MET3prom-SFL1 construct prior to the induction of filamentation completely blocked germ tube formation. To localize Sfl1 in vivo, we generated a SFL1-GFP fusion. Sfl1-green fluorescent protein was found in the nucleus in both yeast cells and, to a lesser extent, hyphal cells. Using reverse transcription-PCR, we find an increased expression of ALS1, ALS3, HWP1, ECE1, and also FLO8. Our results suggest that Sfl1 functions in the repression of flocculation and filamentation and thus represents a novel negative regulator of C. albicans morphogenesis.

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