Function: Probable substrate-specific adapter of an E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. pathway: Protein modification; protein ubiquitination. similarity: Contains 1 BACK (BTB/Kelch associated) domain. similarity: Contains 1 BTB (POZ) domain. similarity: Contains 6 Kelch repeats. subunit: Interacts with cul3.