The Regulation of Gene Activation and Its Application in Biotechnology

The role of trans-acting factors, including transcriptional activators, coactivators, and machinery, in gene activation has been defined through intense study but the mechanistic links within these trans-acting factors and their functional implications are not yet fully understood. As such, establishing a detailed process of gene activation through the study of these trans-acting factors’ functional connections and implications can unravel the mechanism of gene expression and determine the order of events. In the past few years, we used both genetic and biochemical tools available for Saccharomyces cerevisiae to examine the mechanism of INO1 transcriptional activation. INO1 encodes inositol-3-phosphate synthase, which catalyzes the rate-limiting step in the synthesis of inositol. INO1 expression is required for the de novo synthesis of phosphatidylinositol, which has been implicated in complex signaling processes, such as mRNA export, vesicular trafficking, and cell growth and proliferation. As such, INO1 has been chosen as our model system to study the regulation of gene activation. We demonstrated that transcriptional coactivators Snf2p, Ino80p, Gcn5p and Esa1p are involved in INO1 activation. Furthermore, we observed that both Snf2p and Ino80p remodelers departed from the promoter after induction. Our recent findings indicated that both Ino80p and Snf2p can be acetylated by histone acetylases. As such, we propose that the departure action of chromatin remodelers might result from acetylation activity by histones acetylases. A working model of epigenetic modification and transcriptional activation has been proposed. Furthermore, we will also discuss how we combine transcriptional control and gene cloning techniques to build the biosensor for landmine detection.