Regulatory component of the Usp12-46 deubiquitylase complex. activates deubiquitination by increasing the catalytic turnover without increasing the affinity of deubiquitinating enzymes for the substrate. The complex deubiquitylates the wg/wingless-signaling receptor arr/arrow, which stabilizes the receptor and increases its concentration at the cell surface; this enhances the sensitivity of cells to wg/wingless-signal stimulation. This increases the amplitude and spatial range of the signaling response to the wg/wingless morphogen gradient, facilitating the precise concentration-dependent regulation of its target genes. Together with Wdr20 and Usp12-46 required for wg/wingless-mediated signaling in the wing imaginal disc and for wg/wingless-dependent regulation of intestinal stem cell proliferation 