title: Transcriptional responses of Saccharomyces cerevisiae to preferred and nonpreferred nitrogen sources in glucose-limited chemostat cultures.
abstract: Aerobic, glucose-limited chemostat cultures of Saccharomyces cerevisiae grown with six different nitrogen sources were subjected to transcriptome analysis. The use of chemostats enabled an analysis of nitrogen-source-dependent transcriptional regulation at a fixed specific growth rate. A selection of preferred (ammonium and asparagine) and nonpreferred (leucine, phenylalanine, methionine and proline) nitrogen sources was investigated. For each nitrogen source, distinct sets of genes were induced or repressed relative to the other five nitrogen sources. In total, 131 such 'signature transcripts' were identified in this study. In addition to signature transcripts, genes were identified that showed a transcriptional coresponse to two or more of the six nitrogen sources. For example, 33 genes were transcriptionally upregulated in leucine-grown, phenylalanine-grown and methionine-grown cultures; this was partly attributed to the involvement of common enzymes in the dissimilation of these amino acids. In addition to specific transcriptional responses elicited by individual nitrogen sources, their impact on global regulatory mechanisms such as nitrogen catabolite repression (NCR) were monitored. NCR-sensitive gene expression in the chemostat cultures showed that ammonium and asparagine were 'rich' nitrogen sources. By this criterion, leucine, proline and methionine were 'poor' nitrogen sources, and phenylalanine showed an 'intermediate' NCR response.
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan, Delft, The Netherlands.
authors.forename: Viktor M
authors.initials: VM
authors.lastname: Boer
authors.forename: Siew Leng
authors.initials: SL
authors.lastname: Tai
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Vuralhan
authors.forename: Yalun
authors.initials: Y
authors.lastname: Arifin
authors.forename: Michael C
authors.initials: MC
authors.lastname: Walsh
authors.forename: Matthew D W
authors.initials: MD
authors.lastname: Piper
authors.forename: Johannes H
authors.initials: JH
authors.lastname: de Winde
authors.forename: Jack T
authors.initials: JT
authors.lastname: Pronk
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Daran
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D000596:Amino Acids; D000644:Quaternary Ammonium Compounds; D005947:Glucose; D009584:Nitrogen