Glucose regulates transcription in yeast through a network of signaling pathways.
Addition of glucose to yeast cells increases their growth rate and results in a massive restructuring of their transcriptional output. We have used microarray analysis in conjunction with conditional mutations to obtain a systems view of the signaling network responsible for glucose-induced transcriptional changes. We found that several well-studied signaling pathways-such as Snf1 and Rgt-are responsible for specialized but limited responses to glucose. However, 90% of the glucose-induced changes can be recapitulated by the activation of protein kinase A (PKA) or by the induction of PKB (Sch9). Blocking signaling through Sch9 does not interfere with the glucose response, whereas blocking signaling through PKA does. We conclude that both Sch9 and PKA regulate a massive, nutrient-responsive transcriptional program promoting growth, but that they do so in response to different nutritional inputs. Moreover, activating PKA completely recapitulates the transcriptional growth program in the absence of any increase in growth or metabolism, demonstrating that activation of the growth program results solely from the cell's perception of its nutritional status.
Zaman
Shadia
S
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Lippman
Soyeon I
SI
Schneper
Lisa
L
Slonim
Noam
N
Broach
James R
JR
D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000502:physiology*; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011494:Protein Kinases / Q000235:genetics; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics; D015398:Signal Transduction; D014158:Transcription, Genetic; D015003:Yeasts
D011494:Protein Kinases; C071569:SCH9 protein kinase; D051057:Proto-Oncogene Proteins c-akt; D017868:Cyclic AMP-Dependent Protein Kinases; D005947:Glucose