Figure 7.

Model for the regulation of Rst2-binding via UAS loop formation. (A) In glucose-rich conditions, the fbp1 promoter region is packaged in closed chromatin. (B) After glucose starvation, Atf1 activates a cascade of mlonRNA transcriptions, thereby inducing chromatin-configuration change into an open state around UAS1 and UAS2. Rst2 might stabilize Atf1 binding to UAS1. (C) Rst2 and Php2–5 can bind to fbp1 UAS1 and UAS2, respectively. However, Rst2 binding to UAS2 is suppressed by the Tup11/12 corepressors. (D) Php2–5 binding at UAS2 induces local-chromatin remodeling into an open configuration around the TATA box, inducing the formation of a UAS loop. (E) Through the UAS loop, Rst2 bound to UAS1 associates with UAS2.