Shields up: the Tup1–Cyc8 repressor complex blocks coactivator recruitment: Figure 1.

Abstract

The Tup1–Cyc8 complex is responsible for repression of a large and diverse collection of genes in Saccharomyces cerevisiae. The predominant view has been that Tup1–Cyc8 functions as a corepressor, actively associating with regulatory proteins and organizing chromatin to block transcription. A new study by Wong and Struhl in this issue of Genes & Development (pp. 2525–2539) challenges nearly 20 years of models by demonstrating that Tup1–Cyc8 functions primarily as a shield to block DNA-binding proteins from recruiting transcriptional coactivators.