Fig 4.

Architecture and regulation of yeast Hsf1. Relevant domains of the budding yeast transcription factor are indicated. Dashed lines represent regulatory relationships between the NTA (amino-terminal transactivation domain) and the CE2 (control element 2)/RD (regulatory domain) on the CTA (carboxy-terminal transactivation domain). The serine-rich region within the RD is phosphorylated by unknown kinases to promote the repression of the CTA through CE2. As described in the text, the NTA promotes a transient transcriptional response, whereas the CTA is responsible for sustained responses. DBD, DNA-binding domain; HRA/B/LZ, heptad repeats A and B, also called the leucine zipper; P, phosphorylation.