Structure and Function of a Transcriptional Network Activated by Hog1

Cells regulate gene expression using a complex network of signaling pathways, transcription factors and promoters. To gain insight into the structure and function of these networks we analyzed gene expression in single and multiple mutant strains to build a quantitative model of the Hog1 MAPK-dependent osmotic stress response in budding yeast. Our model reveals that the Hog1 and general stress (Msn2/4) pathways interact, at both the signaling and promoter level, to integrate information and create a context-dependent response. Keywords: Stress response network analysis using genetically modified cells 85 samples were used to dissect the structure and function of the Hog1 network (Critical Samples measured in triplicate). The overall strategy was to double mutant or epistasis analysis to break down the influence that genes in the Hog1 network have on each other and the genome-wide stress response. This was done by comparing the expression in strains with different combinations of genes deleted and fitting the data to quantitative models. See Capaldi et. al. Nature Genetics 2008 for details.