FIGURE 8:

Model for transcriptional activation of CWI-responsive genes. In MLP1, those exposed Rlm1-binding sites would allow transcription factor access to the promoter, whereas occluded binding sites within nucleosomes would not be accessible. Under cell wall stress conditions, Slt2 phosphorylates Rlm1, and the SWI/SNF remodeling complex is targeted to the promoters of CWI-responsive genes via interaction with the activated transcription factor. On recruitment, SWI/SNF locally alters nucleosome positioning at the MLP1 promoter, facilitating the binding of Rlm1 to binding sites previously occluded by positioned nucleosomes in a two-step mechanism. Finally, the binding of Pol II stimulates transcription initiation.