The resistance of Candida albicans to many stresses is dependent on the stress-activated protein kinase (SAPK) Hog1. Hence we have explored role Hog1 in regulation transcriptional responses stress. DNA microarrays were used characterize global HOG1 and hog1 cells three stress conditions that activate SAPK: osmotic stress, oxidative heavy metal This revealed both stress-specific a core response C. albicans. was characterized by subset genes responded stereotypical manner all analyzed....

We used transcriptional profiling to investigate the response of fungal pathogen Candida albicans temperature and osmotic oxidative stresses under conditions that permitted >60% survival challenged cells. Each stress generated transient induction a specific set genes including classic markers observed in responses other organisms. noted classical hallmarks general inSaccharomyces cerevisiae are absent from C. albicans; no were significantly induced common three stresses. This observation...

Metabolic adaptation, and in particular the modulation of carbon assimilatory pathways during disease progression, is thought to contribute pathogenicity Candida albicans. Therefore, we have examined global impact glucose upon C. albicans transcriptome, testing sensitivity this pathogen wide-ranging levels (0.01, 0.1, 1.0%). We show that, like Saccharomyces cerevisiae, exquisitely sensitive glucose, regulating central metabolic genes even response 0.01% glucose. This indicates that...

Escherichia coli excretes acetate upon growth on fermentable sugars, but the regulation of this production remains elusive. Acetate excretion excess glucose is thought to be an irreversible process. However, dynamic 13C-metabolic flux analysis revealed a strong bidirectional exchange between E. and its environment. The Pta-AckA pathway was found central for both directions, while alternative routes (Acs or PoxB) play virtually no role in consumption. Kinetic modelling predicted that...

Overflow metabolism refers to the production of seemingly wasteful by-products by cells during growth on glucose even when oxygen is abundant. Two theories have been proposed explain acetate overflow in Escherichia coli – global control central and local pathway but neither accounts for all observations. Here, we develop a kinetic model E. that quantitatively observed behaviours successfully predicts response new perturbations. We reconcile these clarify origin, control, regulation flux....

The dynamic responses of reserve carbohydrates with respect to shortage either carbon or nitrogen source was studied obtain a sound basis for further investigations devoted the characterization mechanisms by which yeast Saccharomyces cerevisiae can cope nutrient limitation during growth. This study carried out in well-controlled bioreactors allow accurate monitoring growth and frequent sampling without disturbing culture. Under glucose limitation, genes involved glycogen trehalose...

ABSTRACT Candida albicans is a pathogenic fungus able to change morphology in response variations its growth environment. Simple inoculation of stationary cells into fresh medium at 37°C, without any other manipulations, appears be powerful but transient inducer hyphal formation; this process also plays significant role classical serum induction formation. The mechanism involve the release repression caused by quorum-sensing molecules stationary-phase cells, and farnesol has strong...

ABSTRACT In Saccharomyces cerevisiae , the (C 2 H ) zinc finger transcription factors Msn2 and Msn4 play central roles in responses to a range of stresses by activating gene via stress response element (STRE; CCCCT). The pathogen Candida albicans displays that are thought help it survive adverse environmental conditions encountered within its human host. However, these differ from those S. hence we predicted Msn2- Msn4-like proteins might have been functionally reassigned C. albicans. has...

ABSTRACT Candida albicans is a major opportunistic pathogen of humans. The pathogenicity this fungus depends upon its ability to deal effectively with the host defenses and, in particular, oxidative burst phagocytic cells. We have explored activation stress response C. ex vivo infection models and during systemic mammalian host. generated strains that contain specific green fluorescent protein (GFP) promoter fusions hence act as biosensors environmental at single-cell level. Having confirmed...

ABSTRACT Candida albicans expresses specific virulence traits that promote disease establishment and progression. These include morphological transitions between yeast hyphal growth forms are thought to contribute dissemination invasion cell surface adhesins attachment the host. Here, we describe regulation of adhesin gene ALS3 , which is expressed specifically during development in C. . Using a combination reporter constructs regulatory mutants, show this mediated by multiple factors at...

Real-time monitoring of the spatial and temporal progression infection/gene expression in animals will contribute greatly to our understanding host-pathogen interactions while reducing number required generate statistically significant data sets. Sensitive vivo imaging technologies can detect low levels light emitted from luciferase reporters vivo, but existing are not optimal for fungal infections. Therefore, aim was develop a novel reporter system Candida albicans infections that overcomes...

In budding yeast, Tup1 and Ssn6/Cyc8 form a corepressor that regulates large number of genes. This Tup1-Ssn6 appears to be conserved from yeast man. the pathogenic fungus Candida albicans, cellular morphogenesis, phenotypic switching, metabolism, but role Ssn6 remains unclear. We show there are clear differences in morphological invasive phenotypes C. albicans ssn6 tup1 mutants. Unlike Tup1, depletion promoted events reminiscent switching rather than filamentous growth. Transcript profiling...

Signal-mediated interactions between the human opportunistic pathogens Pseudomonas aeruginosa and Candida albicans affect virulence traits in both organisms. Phenotypic studies revealed that bacterial supernatant from four P. strains strongly reduced ability of C. to form biofilms on silicone. This was largely a consequence inhibition biofilm maturation, phenomenon also observed with prepared non-clinical species. The effects formation were not mediated via interference yeast-hyphal...

Abstract Acetate, a major by‐product of glycolytic metabolism in Escherichia coli and many other microorganisms, has long been considered toxic waste compound that inhibits microbial growth. This counterproductive auto‐inhibition represents problem biotechnology puzzled the scientific community for decades. Recent studies have however revealed acetate is also co‐substrate nutrients global regulator E. physiology. Here, we used systems biology strategy to investigate mutual regulation ....

ABSTRACT Growth of Escherichia coli on glucose in batch culture is accompanied by the excretion acetate, which consumed cells when exhausted. This glucose-acetate transition classically described as a diauxie (two successive growth stages). Here, we investigated physiological and metabolic properties after exhaustion through analysis parameters gene expression. We found that E. grown produce acetate consume it but do not grow acetate. Acetate catabolized, key anabolic genes—such genes...

Metabolic control in Escherichia coli is a complex process involving multilevel regulatory systems but the involvement of post-transcriptional regulation uncertain. The factor CsrA stated as being only regulator essential for use glycolytic substrates. A dozen enzymes central carbon metabolism (CCM) have been reported potentially controlled by CsrA, its impact on CCM functioning has not demonstrated. Here, multiscale analysis was performed wild-type strain and isogenic mutant attenuated...

The glucose-acetate transition in Escherichia coli is a classical model of metabolic adaptation. Here, we describe the dynamics molecular processes involved this transition, with particular focus on glucose exhaustion. Although changes metabolome were observed before exhaustion, our results point to massive reshuffling at both transcriptome and levels very first min following A new transcriptional pattern, involving change genome expression one-sixth E. genome, was established within 10...

Micro-organisms must adapt to environmental change survive, and this is particularly true for fungal pathogens such as Candida glabrata. C. glabrata found both in the environment diverse niches its human host. The ambient pH of these varies considerably, therefore we have examined response changes using a proteomic approach. Proteins expressed cells growing at 4.0, 7.4 or 8.0 were compared by 2-DE, 174 spots displaying reproducible statistically significant expression level identified...

Candida albicans is more pathogenic than dubliniensis. However, this disparity in virulence surprising given the high level of sequence conservation and wide range phenotypic traits shared by these two species. Increased sensitivity to environmental stresses has been suggested be a possible contributory factor lower C. In study, we investigated, first comparison dubliniensis transcriptional profiling, global gene expression each species when grown under conditions which exhibit differential...

DHA is an attractive triose molecule with a wide range of applications, notably in cosmetics and the food pharmaceutical industries. found many species, from microorganisms to humans, can be used by Escherichia coli as growth substrate. However, knowledge about mechanisms regulation this process currently lacking, motivating our investigation metabolism E. . We show that under aerobic conditions, on far optimal hindered chemical, hierarchical, possibly allosteric constraints. restored...

For a better understanding of the systemic effect sub-lethal micromolar concentrations ionic silver on Escherichia coli, we performed multi-level characterization cells under Ag+-mediated stress using an integrative biology approach combining physiological, biochemical and transcriptomic data. Physiological parameters, namely bacterial growth survival after Ag+ exposure, were first quantified related to accumulation intracellular silver, probed for time by nano secondary ion mass...

The YPR184w gene encodes a 1536-amino acid protein that is 34-39% identical to the mammal, Drosophila melanogaster and Caenorhabditis elegans glycogen debranching enzyme. N-terminal part of possesses four conserved sequences alpha-amylase superfamily, while C-terminal displays 50% similarity with other eukaryotic enzymes. Reliable measurement alpha-1,4-glucanotransferase alpha-1, 6-glucosidase activity yeast enzyme was determined in strains overexpressing YPR184w. 4-glucanotransferase...

Mutant strains of Saccharomyces cerevisiae defective in respiration have been reported to be unable store glycogen, as revealed by the iodine-staining method. In this report, it is shown that contrast claim, mitochondrial respiratory mutants accumulated even more glycogen than wild-type cells during fermentative growth on glucose. However, soon glucose was exhausted medium, these readily and completely mobilized their content, contrary which only transiently degraded polymer. The...

ABSTRACT In the bacterium Escherichia coli , posttranscriptional regulatory system Csr was postulated to influence transition from glycolysis gluconeogenesis. Here, we explored role of in glucose-acetate as a model glycolysis-to-gluconeogenesis switch. Mutations reorganization gene expression after glucose exhaustion and disturb timing acetate reconsumption exhaustion. Analysis metabolite concentrations during revealed that has major effect on energy levels cells This demonstrated result...