WDR82 (D2I3B) Rabbit mAb #99715

The Set1 histone methyltransferase protein was first identified in yeast as part of the Set1/COMPASS histone methyltransferase complex, which methylates histone H3 at Lys4 and functions as a transcriptional co-activator (1). While yeast contain only one known Set1 protein, six Set1-related proteins exist in mammals: SET1A, SET1B, MLL1, MLL2, MLL3, and MLL4, all of which assemble into COMPASS-like complexes and methylate histone H3 at Lys4 (2,3). These Set1-related proteins are each found in distinct protein complexes, all of which share the common subunits WDR5, RBBP5, ASH2L, CXXC1 and DPY30. These subunits are required for proper complex assembly and modulation of histone methyltransferase activity (2-6). MLL1 and MLL2 complexes contain the additional protein subunit, menin (6). Like yeast Set1, all six Set1-related mammalian proteins methylate histone H3 at Lys4 (2-6). MLL translocations are found in a large number of hematological malignancies, suggesting that Set1/COMPASS histone methyltransferase complexes play a critical role in leukemogenesis (6).
WDR82 is a core subunit specific to the SET1A and SET1B COMPASS-like complexes (4,5). WDR82 facilitates methylation of histone H3 lysine 4 during transcriptional activation by binding to Ser5-phosphorylated Rpb1 CTD and ubiquityl-H2B, and recruiting SET1A/SET1B complexes to the transcription start site of genes (7,8). WDR82 is also a component of the PTW/PP1 phosphatase complex that functions to regulate chromatin structure and cell cycle progression during the transition from mitosis to interphase (9).