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Candida albicans exhibits enhanced alkaline and temperature induction of Efg1-regulated transcripts relative to Candida dubliniensis.

Caplice N, Moran GP - Genom Data (2015)

Bottom Line: Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis.We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis.Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

View Article: PubMed Central - PubMed

Affiliation: Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Dublin 2, Ireland.

ABSTRACT
Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis. In this meta-analysis, we compare the transcriptional response of C. dubliniensis and C. albicans to the individual environmental stimuli that shape the gene expression profiles during filamentation in 10% serum, namely alkaline pH, 37 °C and reduced cell density. We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis. Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

No MeSH data available.


Related in: MedlinePlus

Expression of selected genes in C. dubliniensis from microarray experiments. (a) Expression of UME6 following inoculation of cells from overnight Lee's medium pH 4.5 cultures to fresh medium at 30 °C, 37 °C, nutrient depleted Lee's medium or Lee's buffered to pH 7.2, respectively. Data from previously reported experiments where Lee's grown cells were inoculated to 10% (v/v) bovine serum and grown for 1 h, 3 h and 5 h are also shown for comparison. (b) Heat map showing the expression patterns of selected Efg1-regulated and hypha-induced transcripts in C. dubliniensis.
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f0020: Expression of selected genes in C. dubliniensis from microarray experiments. (a) Expression of UME6 following inoculation of cells from overnight Lee's medium pH 4.5 cultures to fresh medium at 30 °C, 37 °C, nutrient depleted Lee's medium or Lee's buffered to pH 7.2, respectively. Data from previously reported experiments where Lee's grown cells were inoculated to 10% (v/v) bovine serum and grown for 1 h, 3 h and 5 h are also shown for comparison. (b) Heat map showing the expression patterns of selected Efg1-regulated and hypha-induced transcripts in C. dubliniensis.

Mentions: As nutrient depletion has a strong effect on filamentous growth in C. dubliniensis, we examined the transcript profile of strain Wü284 following dilution to 10% (v/v) Lee's medium (pH 4.5). Genes that exhibited a significant change in expression relative to dilution alone were examined (Tables S7 and S8). This group of genes was found to be enriched for those involved in carbohydrate metabolism, particularly mobilisation of glycogen stores (GLC1, GSY3) and phosphorylation of glucose for entry to glycolysis (GLK1, GLK4, PGM2). Catabolism of alternative sugars was also induced (ARA1, GRE3, XYL1, XYL2). Nitrogen starvation was suggested by increased expression of genes involved in amino acid degradation (CAR1, PNG2), protein degradation (PRC2, LAP3) and scavenging of nitrogen from the environment (DAL7, GAP2, DUR3). These data provide a link between the response to nutrient depletion and filamentation as a 4.3-fold induction of UME6 transcription was observed. Previously, we have observed induction of UME6 in nutrient poor, alkaline, hypha inducing conditions (water plus 10% serum), and this induction was repressed by the addition of peptone [18]. The data presented here demonstrate that the nutrient depleted media, in the absence of temperature or pH shifts, can contribute to UME6 induction. Previous microarray and QRT-PCR studies have shown that the level of UME6 induction in C. dubliniensis is of the order of ~ 100-fold following inoculation in water plus 10% serum (Fig. 4a). The microarray data presented here indicate that this level of induction may involve the integration of several different stimuli including temperature, nutrient depletion and alkaline pH (Fig. 4a). The level of UME6 induction has previously been shown to dictate the level of hyphal elongation and these data provide further evidence that efficient filamentation in C. dubliniensis requires multiple environmental stimuli, including nutrient depletion [26].


Candida albicans exhibits enhanced alkaline and temperature induction of Efg1-regulated transcripts relative to Candida dubliniensis.

Caplice N, Moran GP - Genom Data (2015)

Expression of selected genes in C. dubliniensis from microarray experiments. (a) Expression of UME6 following inoculation of cells from overnight Lee's medium pH 4.5 cultures to fresh medium at 30 °C, 37 °C, nutrient depleted Lee's medium or Lee's buffered to pH 7.2, respectively. Data from previously reported experiments where Lee's grown cells were inoculated to 10% (v/v) bovine serum and grown for 1 h, 3 h and 5 h are also shown for comparison. (b) Heat map showing the expression patterns of selected Efg1-regulated and hypha-induced transcripts in C. dubliniensis.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4664712&req=5

f0020: Expression of selected genes in C. dubliniensis from microarray experiments. (a) Expression of UME6 following inoculation of cells from overnight Lee's medium pH 4.5 cultures to fresh medium at 30 °C, 37 °C, nutrient depleted Lee's medium or Lee's buffered to pH 7.2, respectively. Data from previously reported experiments where Lee's grown cells were inoculated to 10% (v/v) bovine serum and grown for 1 h, 3 h and 5 h are also shown for comparison. (b) Heat map showing the expression patterns of selected Efg1-regulated and hypha-induced transcripts in C. dubliniensis.
Mentions: As nutrient depletion has a strong effect on filamentous growth in C. dubliniensis, we examined the transcript profile of strain Wü284 following dilution to 10% (v/v) Lee's medium (pH 4.5). Genes that exhibited a significant change in expression relative to dilution alone were examined (Tables S7 and S8). This group of genes was found to be enriched for those involved in carbohydrate metabolism, particularly mobilisation of glycogen stores (GLC1, GSY3) and phosphorylation of glucose for entry to glycolysis (GLK1, GLK4, PGM2). Catabolism of alternative sugars was also induced (ARA1, GRE3, XYL1, XYL2). Nitrogen starvation was suggested by increased expression of genes involved in amino acid degradation (CAR1, PNG2), protein degradation (PRC2, LAP3) and scavenging of nitrogen from the environment (DAL7, GAP2, DUR3). These data provide a link between the response to nutrient depletion and filamentation as a 4.3-fold induction of UME6 transcription was observed. Previously, we have observed induction of UME6 in nutrient poor, alkaline, hypha inducing conditions (water plus 10% serum), and this induction was repressed by the addition of peptone [18]. The data presented here demonstrate that the nutrient depleted media, in the absence of temperature or pH shifts, can contribute to UME6 induction. Previous microarray and QRT-PCR studies have shown that the level of UME6 induction in C. dubliniensis is of the order of ~ 100-fold following inoculation in water plus 10% serum (Fig. 4a). The microarray data presented here indicate that this level of induction may involve the integration of several different stimuli including temperature, nutrient depletion and alkaline pH (Fig. 4a). The level of UME6 induction has previously been shown to dictate the level of hyphal elongation and these data provide further evidence that efficient filamentation in C. dubliniensis requires multiple environmental stimuli, including nutrient depletion [26].

Bottom Line: Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis.We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis.Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

View Article: PubMed Central - PubMed

Affiliation: Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Dublin 2, Ireland.

ABSTRACT
Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis. In this meta-analysis, we compare the transcriptional response of C. dubliniensis and C. albicans to the individual environmental stimuli that shape the gene expression profiles during filamentation in 10% serum, namely alkaline pH, 37 °C and reduced cell density. We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis. Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

No MeSH data available.


Related in: MedlinePlus