In the process of mRNA degradation, seems to play a role in mRNA decapping. Component of a complex containing DCP2 and DCP1A which functions in decapping of ARE-containing mRNAs. Promotes complex formation between DCP1A and DCP2. Enhances the catalytic activity of DCP2 (in vitro). Part of a decapping complex consisting of DCP1A, DCP2, EDC3, EDC4 and probably DDX6. Part of a complex consisting of DCP1A, EDC3, EDC4 and DDX6. Part of a complex consisting of DCP1B, EDC3, EDC4 and DDX6. Interacts with DCP2 (By similarity). Interacts with RC3H1 (PubMed:20639877, PubMed:23583643). Interacts with NBDY (By similarity). Interacts with Tex19.1 and, probably, Tex19.2 (PubMed:28254886). Interacts with LSM14A (By similarity). Interacts with DDX6 (By similarity). Belongs to the WD repeat EDC4 family.