Master regulators refer to transcription factors whose ectopic expression alone is capable of activating a cellular process. Master regulators have extremely important applications in regulating biological processes including cancer development and progression for therapeutic purposes. For instance, they can be used to bypass upstream deficiencies in a pathway and therefore restore the normal functions of the pathway. So far only a limited number of master regulators have been identified. In order to identify master regulators in other important eukaryotic processes, this research is to test the hypothesis that factors with the most incoming connections in a transcriptional network, namely target hubs, are likely master regulators. The transcription regulatory networks formed by ten key regulators of the osmotic response in Saccharomyces cerevisiae will be studied using chromatin immunoprecipitation and microarray analysis (chIP chip) with the goals of identifying target hubs. Whether these target hubs function as master regulators will be investigated. Finally, candidate target hubs and master regulators in additional cellular processes will be identified using the existing chIP chip data from other sources by computational strategies. ? ? ?
