Fig. 9

A general model of enhancer-dependent transcriptional activation by Pax6 through recruitment of chromatin-modifying and remodeling complexes. The present data coupled with earlier studies on Pax6 suggest a general model that explains chromatin features near Pax6-bound peaks. The Pax6/Brg1- and Pax6/Snf2h-containing ATP chromatin remodeling complexes are initially assembled in the enhancer and promoter regions. Pax6 is then joined by additional DNA-binding factors (not shown). In subsequent stages, enhancer-bound Pax6 recruits Mll1/2 complexes and the region is marked by H3K4me1 and H3K4me2, followed by recruitment of p300, and generation of H3K27ac. Similarly, at the promoter regions, binding of Pax6 facilitates recruitment of cooperating DNA-binding factors (shown: Maf and Sox2), followed by various chromatin-modifying and remodeling activities, and formation of physical contacts between these assemblies mediated by DNA looping. As the transcription commences, Set1a traveling with the RNA polymerase will convert the unmodified and partially methylated H3K4 residues into the high density of H3K4me3