Fig. 4

ASXL1/2 and trithorax gene activation by MLL3/MLL4 COMPASS and MLL5. MLL3/MLL4 COMPASS is composed of the WRAD complex of proteins (WDR5, ASH2, RBBP5, and DPY30), which is required for H3K4 methyltransferase activity, as well as NCOA6, PA1, BAP1 (interacts with ASXL1 or ASXL2), and the H3K27 demethylase UTX. ASXL1 interacts with OGT1 and HCFC1 to form a complex that collaborates with MLL5 for the trimethylation of H3K4. The deposition of H3K4me1 by MLL3/MLL4 at enhancers, demethylation of H3K27 by UTX, and the deposition of H3K4me3 by MLL5 facilitate transcriptional activation