May modulate activity of cullin-RING E3 ubiquitin ligase (CRL) complexes (PubMed:21778237). May down-regulate activation of NF-kappa-B (PubMed:15799966). Modulates Na(+) transport in epithelial cells by regulation of apical cell surface expression of amiloride-sensitive sodium channel (ENaC) subunits (PubMed:23637203). Interacts (via COMM domain) with COMMD1 (via COMM domain). Interacts with NFKB1/p105. Interacts with CCDC22, CCDC93, SCNN1B, CUL3, CUL4A, CUL4B, CUL5. Widely expressed with highest expression in thymus.