Component of the SET1 complex that specifically di- and trimethylates 'Lys-4' of histone H3 (PubMed:21694722, PubMed:21875999). Together with su(sable), part of a transcription termination checkpoint that promotes transcription termination of aberrant RNAs and their subsequent degradation by the nuclear exosome (PubMed:26577379). Component of the SET1 complex, composed at least of the catalytic subunit Set1, wds/WDR5, Wdr82, Rbbp5, ash2, Cfp1/CXXC1, hcf and Dpy-30L1 (PubMed:21694722, PubMed:21875999). Interacts with male-specific lethal (MSL) histone acetyltransferase complex at least composed of mof, msl-1, msl-2 and msl-3 (PubMed:23295261). Interacts with su(sable) (PubMed:26577379). Belongs to the WD repeat SWD2 family.