Serves as substrate adapter subunit in the E3 ubiquitin ligase complex ZYG11B-CUL2-Elongin BC (PubMed:17304241, PubMed:31273098). Acts to target substrates bearing N-terminal degrons for proteasomal degradation with the first four residues of substrates being the key recognition elements (PubMed:33093214, PubMed:34214466, PubMed:36496439). Involved in the clearance of proteolytic fragments generated by caspase cleavage during apoptosis since N-terminal glycine degrons are strongly enriched at caspase cleavage sites. Also important in the quality control of protein N-myristoylation in which N-terminal glycine degrons are conditionally exposed after a failure of N-myristoylation (PubMed:31273098).