Flow-injection analysis of Saccharomyces cerevisiae mutant AYT1
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ABSTRACT: The intracellular metabolome of S. cerevisiae mutants in the gene AYT1 were measured under glucose growth conditions, as well as growth on oleate.
Project description:The intracellular metabolome of S. cerevisiae mutants in the gene AYT1 were measured under glucose growth conditions, as well as growth on oleate.
Project description:To understand the organisation of the glucose regulatory system, we analysed 91 deletion mutants of established glucose signalling and metabolic pathway members in Saccharomyces cerevisiae by DNA microarrays. These deletion mutants do not induce pathway-specific transcriptional responses reflecting the tight interconnection between pathways of the glucose regulatory system. Instead, one main transcriptional response is discerned, which varies in direction to mimic either a high or a low glucose response. The study reveals both known and unknown relationships within and between individual pathways and their members. Metabolic components of the glucose regulatory system are most frequently affected at the transcriptional level. A new network approach is applied that exposes the hierarchical organisation of the glucose regulatory system. Tps2 and Tsl1, two enzymes involved in trehalose biosynthesis, are predicted to be the most downstream transcriptional components. This prediction is further validated by epistasis analysis of Tps2 double mutants. Taken together, this suggests that changes in perceived glucose levels ultimately lead to a shift in trehalose biosynthesis.
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Galpha protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Keywords: Saccharomyces cerevisiae, nitrogen starvation, maltose, pseudohyphal differentiation, yeast, expression profiling
Project description:Saccharomyces cerevisiae inducible overexpression mutants were treated with the indicated concentration of inducers for 1.5 and 3 hours before the intracellular metabolome was collected. Samples were subjected to LCMS analysis in negative mode with separation by an InfinityLab Poroshell 120 HILIC-Z column (2.1 x 100 mm, 2.7 um, Agilent)
Project description:In response to carbon source switching from glucose to non-glucose, such as ethanol and galactose, yeast cells can directionally preprogram cellular metabolism to efficiently utilize the nutrients. However, the understanding of cellular responsive network to utilize a non-natural carbon source, such as xylose, is limited due to the incomplete knowledge on the xylose response mechanisms. Here, through optimization of the xylose assimilation pathway together with combinational evaluation of reported targets, we generated a series of mutants with varied growth ability. However, understanding how cells respond to xylose and remodel cellular metabolic network is far insufficient based on current information. Therefore, genome-scale transcriptional analysis was performed to unravel the cellular reprograming mechanisms underlying the improved growth phenotype.
Project description:One of the essential or beneficial micronutrient for plants and animals is boron that is an ultra-trace element. Although boron can inhibit the growth of Saccharomyces cerevisiae around 80 mM, it is also a growth supplement. However, little information is currently available regarding the molecular mechanisms and essentiality of boron. In this paper, the approach was to generate S. cerevisiae mutants with high boron resistance by using evolutionary engineering strategy that was previously applied successfully. Boron-resistant S. cerevisiae mutants were obtained and their phenotypic and physiological characteristics were determined. In order to identify the molecular mechanisms implicated in boron resistance, the whole transcriptomes and genome sequence analysis of wild type and one of the most resistant mutants were compared.
Project description:To understand the organisation of the glucose regulatory system, we analysed 91 deletion mutants of established glucose signalling and metabolic pathway members in Saccharomyces cerevisiae by DNA microarrays. These deletion mutants do not induce pathway-specific transcriptional responses reflecting the tight interconnection between pathways of the glucose regulatory system. Instead, one main transcriptional response is discerned, which varies in direction to mimic either a high or a low glucose response. The study reveals both known and unknown relationships within and between individual pathways and their members. Metabolic components of the glucose regulatory system are most frequently affected at the transcriptional level. A new network approach is applied that exposes the hierarchical organisation of the glucose regulatory system. Tps2 and Tsl1, two enzymes involved in trehalose biosynthesis, are predicted to be the most downstream transcriptional components. This prediction is further validated by epistasis analysis of Tps2 double mutants. Taken together, this suggests that changes in perceived glucose levels ultimately lead to a shift in trehalose biosynthesis. RNA isolated from a large amount of wt yeast from a single culture was used as a common reference. This common reference was used for each separate hybridization and used in the statistical analysis to obtain an average expression-profile for each deletion mutant relative to the wt. Two independent cultures were hybridized on two separate microarrays. For the first hybridization the Cy5 (red) labeled cRNA from the deletion mutant is hybridized together with the Cy3 (green) labeled cRNA from the common reference. For the replicate hybridization, the labels are swapped. Each gene is represented twice on the microarray, resulting in four measurements per mutant. Up to five deletion strains were grown on a single day. Wt cultures were grown parallel to the deletion mutants to assess day-to-day variance.
Project description:Saccharomyces cerevisiae is an excellent microorganism for industrial succinic acid production, but high succinic acid concentration will inhibit the growth of Saccharomyces cerevisiae then reduce the production of succinic acid. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different genetic backgrounds under different succinic acid stress, we hope to find the response mechanism of Saccharomyces cerevisiae to succinic acid.