Component of the SET1 complex that specifically di- and trimethylates 'Lys-4' of histone H3 and of the MLL3/4 complex which also methylates histone H3 'Lys-4'. Inhibits MTF-1 transcription factor activity. Core component of several methyltransferase-containing complexes. Component of the SET1 complex, composed at least of the catalytic subunit Set1, wds/WDR5, Wdr82, Rbbp5, ash2, Cfp1/CXXC1, hcf and Dpy-30L1. Component of the MLL3/4 complex composed at least of the catalytic subunit trr, ash2, Rbbp5, Dpy-30L1, wds, hcf, ptip, Pa1, Utx, Lpt and Ncoa6. Expressed in larval brain, gonad, imaginal disk and salivary gland and in adult brain, testis, ovary and salivary gland. Viable and fertile with no overt disruption of metal homeostasis. Belongs to the dpy-30 family.