Saccharomyces cerevisiae JEN1 promoter activity is inversely related to concentration of repressing sugar

• Published in: Applied and Environmental Microbiology 2004, Vol.70 (1), p.8-17
• Main Authors: Chambers, P, Issaka, A, Palecek, S.P
• Format: Article
• Language: English
• Subjects: abiotic stress; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological and medical sciences; Biosensing Techniques; biosensors; Carbohydrate Metabolism; Carbon; chemical concentration; cold stress; Culture Media; DNA damage; Fundamental and applied biological sciences. Psychology; Gene expression; gene expression regulation; Gene Expression Regulation, Fungal; glucose; Glucose - metabolism; green fluorescent protein; Green Fluorescent Proteins; heat stress; lactate-pyruvate transporter; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Microbiology; Monocarboxylic Acid Transporters - genetics; Monocarboxylic Acid Transporters - metabolism; osmotic pressure; Physiology and Biotechnology; promoter regions; Promoter Regions, Genetic; reporter genes; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; sugars; Symporters - genetics; Symporters - metabolism; transcription (genetics); transporters; yeasts
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.70.1.8-17.2004

When carbon sources are changed, Saccharomyces cerevisiae transcriptional patterns drastically change. To identify genes whose transcription can be used to quantitatively measure sugar concentrations, we searched genomic expression databases for a set of genes that are highly induced during the diauxic shift, and we used the promoters from these genes to drive expression of green fluorescent protein (GFP). Certain sugars, including glucose, fructose, and mannose, repress the promoter of JEN1, which encodes a lactate-pyruvate transporter, in a dose-dependent manner. Nonrepressing carbon sources include galactose, raffinose, ethanol, lactate, and glycerol. JEN1 promoter activity is a linear function of glucose concentration when organisms are grown at a steady-state glucose concentration below 1 g/liter. JEN1 promoter repression is specific to carbon source; heat or cold shock, osmotic stress, DNA damage, and nitrogen starvation do not significantly affect promoter activity. Activation of the JEN1 promoter requires the Snf1 protein kinase, but multiple regulatory elements most likely combine to provide the linear relationship between JEN1 promoter activity and sugar concentration. Thus, a JEN1 promoter-reporter system appears to provide a good living cell biosensor for the concentration of certain sugars. The JEN1 promoter also permits quantitative regulation of cellular functions not normally controlled by sugar concentrations. For example, a strain expressing FLO1 under control of the JEN1 promoter flocculates at a low glucose concentration.