Activators of RNA polymerase II transcription possess distinct and separable DNA-binding and transcriptional activation domains. They are thought to function by binding to specific sites on DNA and interacting with proteins (transcription factors) binding near to the transcriptional start site of a gene. The ability of these proteins to activate transcription is a highly regulated process, with activation only occurring under specific conditions to ensure proper timing and levels of target gene expression. Such regulation modulates the ability of transcription factors either to bind DNA or to interact with the transcriptional machinery. Here we discuss recent advances in our understanding of these mechanisms of transcriptional regulation in yeast.