Figure 8

The recruit and maintain (RAM) model to explain the transient requirement for Mll2. The diagram illustrates two nucleosomes at a gene promoter, to which Mll2 is recruited. Once recruited, Mll2 mediates the establishment of a back-up system, partly via H3K4 trimethylation, which is based on its sister, Mll, and potentially the other H3K4 methyltransferase pairs, Set1A/Set1B and Mll3/Mll4. The epitopes, x and y, are included to indicate that other chromatin determinants are likely to play roles in recruitment and maintenance.