Enables mRNA 3'-UTR binding activity. Acts upstream of or within several processes, including 3'-UTR-mediated mRNA stabilization; regulation of smoothened signaling pathway; and skeletal myofibril assembly. Predicted to be located in cytoplasm. Predicted to be active in nucleus. Is expressed in several structures, including heart tube; mesoderm; musculature system; nervous system; and solid lens vesicle. Orthologous to human QKI (QKI, KH domain containing RNA binding).