SIGNALING ACTIVATION AND REPRESSION OF RNA-POLYMERASE-II TRANSCRIPTION IN YEAST

Activators of RNA polymerase II transcription possess distinct and sep arable DNA-binding and transcriptional activation domains. They are th ought to function by binding to specific sites on DNA and interacting with proteins (transcription factors) binding near to the transcriptio nal start site of a gene. The ability of these proteins to activate tr anscription is a highly regulated process, with activation only occurr ing under specific conditions to ensure proper timing and levels of ta rget gene expression. Such regulation modulates the ability of transcr iption factors either to bind DNA or to interact with the transcriptio nal machinery. Here we discuss recent advances in our understanding of these mechanisms of transcriptional regulation in yeast.