Abstract:
In this study, a genome-scale transcriptional regulatory network (TRN) in S. cerevisiae was constructed and integrated with the transcriptome data available in literature for the mutants of the glucose signaling pathway of S. cerevisiae to identify key transcription factors (transcription factors around which a considerable collective change in the expression of the genes occur in response to environmental and genetic perturbations). Identification of key transcription factors demonstrates the regulatory mechanisms invoked in the cell and potential biomarkers, without a priori requirement of change in the transcription level of the transcription factors. Biologically meaningful key transcription factors identified with this approach shed light on the transcriptional regulatory mechanism controlling the glucose signaling in S. cerevisiae. For example, key transcription factors identified in SNF1 reveal the predicted role of Snf1p kinase, highlighting the effectiveness of the approach used and a large genome-scale TRN. In this study, after the key transcription factors were identified, the perturbation-responsive subnetworks were constructed by interconnecting key transcription factors and their differentially expressed target genes responsive to the same perturbation. Based on whether the key transcription factors have their differential expression changed significantly, it was investigated if the transcription factors are regulated mainly transcriptionally or mainly post-transcriptionally.
