Figure 8.

Possible mechanisms for stress-specific binding of Msn2 to different sets of genes. (A) Different stresses could result in distinct modifications (red versus green dots) of Msn2 (blue oval), which could alter the binding specificity or the nuclear occupancy dynamics and which would lead to interaction with different but overlapping sets of stress-responsive genes. (B) Different stresses could activate Msn2 (blue oval) as well as a stress-specific transcription factor (red oval for nutrient stress and green oval for oxidative stress). Those genes with STREs lying in nucleosome-free domains would bind Msn2 under either condition. However, binding of the stress-specific transcription factor could partially unwrap adjacent nucleosomes (beige ovals) to reveal additional, previously inaccessible STREs to which Msn2 could bind.