May act as a substrate-specific adapter of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Protein modification; protein ubiquitination. The BTB/POZ domain mediates the interaction with some component of ubiquitin ligase complexes. Was originally thought to correspond to two different genes At2g30600 and At2g30610. Was originally thought to correspond to two different genes At2g30600 and At2g30610.