Substrate recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex, SCF(FBXO3), which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:18809579, PubMed:26037928). Mediates the ubiquitination of HIPK2 and probably that of EP300, leading to rapid degradation by the proteasome (PubMed:18809579). In the presence of PML, HIPK2 ubiquitination still occurs, but degradation is prevented (PubMed:18809579). PML, HIPK2 and FBXO3 may act synergically to activate p53/TP53-dependent transactivation (PubMed:18809579). The SCF(FBXO3) also acts as a regulator of inflammation by mediating ubiquitination and degradation of FBXL2 in response to lipopolysaccharide (LPS) (PubMed:26037928). The SCF(FBXO3) complex specifically recognizes FBXL2 phosphorylated at ‘Thr-404’ and promotes its ubiquitination (By similarity).