Substrate-specific adapter of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex involved in regulation of cytoskeleton structure. The BCR(TNFAIP1) E3 ubiquitin ligase complex mediates the ubiquitination of RHOA, leading to its degradation by the proteasome, thereby regulating the actin cytoskeleton and cell migration. Its interaction with RHOB may regulate apoptosis (By similarity). May enhance the PCNA-dependent DNA polymerase delta activity. Protein modification; protein ubiquitination. Component of the BCR(TNFAIP1) E3 ubiquitin ligase complex, at least composed of CUL3, TNFAIP1/BACURD2 and RBX1. Interacts with RHOA; with a preference for RhoA-GDP. Interacts with RHOB. Interacts with CSNK2B (By similarity). Interacts with PCNA. Colocalizes with RHOB in endosomes. Phosphorylation at Ser-280 by CK2 facilitates the nucleus localization and increases interaction with PCNA. Belongs to the BACURD family.