Probable core component of cullin-based SCF-like E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins (By similarity). The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit (By similarity). Involved in ER-Golgi transport by regulating the size of COPII coats, thereby playing a key role in collagen export, which is required for embryonic stem (ES) cells division (By similarity). May play a role in the regulation of mittotic entry via ubiquitination of aurka (By similarity). Protein modification; protein ubiquitination. Component of multiple BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complexes formed of cul3, rbx1 and a variable BTB domain-containing protein acting as both, adapter to cullin and substrate recognition subunit (By similarity). Interacts with btbd6 (PubMed:18855900). Neddylated. Attachment of NEDD8 is required for the E3 ubiquitin-protein ligase activity of the SCF-like complex. Belongs to the cullin family.