Substrate receptor subunit of a cullin-RING superfamily E3 ligase complex (CUL5-based E3 ubiquitin ligase complex) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:30293565). Depending of the metabolic state of the cell, promotes the proteasomal degradation of IMPDH2, the rate-limiting enzyme in GTP biosynthesis or protects IMPDH2 by stabilizing IMPDH2 filaments assembly (PubMed:30293565, PubMed:31337707). Implicated in different cellular processes, like copper homeostasis and cell proliferation (PubMed:24522796, PubMed:30293565).
