As part of the MLL1/MLL complex it is involved in methylation and dimethylation at 'Lys-4' of histone H3. H3 'Lys-4' methylation represents a specific tag for epigenetic transcriptional activation. Component of the SET1 complex, at least composed of the catalytic subunit (SETD1A or SETD1B), WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1 and DPY30. Core component of several methyltransferase-containing complexes including MLL1/MLL, ASCOM, MLL2/MLL3 and MLL3/MLL4. Each complex is at least composed of ASH2L, RBBP5, DPY30, WDR5, one or more specific histone methyltransferases (MLL, MLL2, MLL3 and MLL4), and the facultative components C16orf53/PA1, C17orf49, CHD8, E2F6, HCFC1, HCFC2, HSP70, INO80C, KDM6A, KANSL1, LAS1L, MAX, MCRS1, MEN1, MGA, MYST1/MOF, NCOA6, PAXIP1/PTIP, PELP1, PHF20, PRP31, RING2, RUVB1/TIP49A, RUVB2/TIP49B, SENP3, TAF1, TAF4, TAF6, TAF7, TAF9 and TEX10. Interacts with WDR5 and ASH2L; the interaction is direct. Interacts with WDR82 and SETD1A. Ubiquitously expressed. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Transcription, coactivator/corepressor