Substrate-recognition component of a DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complex, which mediates ubiquitination of target proteins, leading to their degradation (PubMed:30670470, PubMed:31857346). Required for synaptic function and plasticity at larval neuromuscular junctions (NMJs) by promoting neurotransmitter release (PubMed:30670470). The DCX(DCAF12) complex catalyzes ubiquitination and degradation of yorkie (yki), thereby regulating the Hippo/SWH (Sav/Wts/Hpo) signaling pathway (PubMed:31857346). Acts as a regulator of tissue growth during development: required for the apoptotic elimination of supernumerary cells during metamorphosis (PubMed:26972874). Protein modification; protein ubiquitination. Substrate-recognition component of a DCX (DDB1-CUL4-X-box) protein ligase complex. Mainly localizes to presynapses in larval neuromuscular junctions. In larvae, expressed in neurons, glia and muscles. Embryonic lethality. Belongs to the WD repeat DCAF12 family.