Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Probably recognizes and binds to phosphorylated target proteins. Recognizes YBX1 (By similarity). Protein modification; protein ubiquitination. Part of the SCF (SKP1-CUL1-F-box) E3 ubiquitin-protein ligase complex SCF(FBXO33) formed of CUL1, SKP1, RBX1 and FBXO33. Interacts via its N-terminus with YBX1 CSD domain. Directly interacts with SKP1 and CUL1 (By similarity).