F-box only protein 3 (FBXO3)

Substrate recognition part of the SCF (SKP1-CUL1-F- box protein)-type E3 ubiquitin ligase complex. Mediates the ubiquitination of HIPK2 and probably that of EP300, leading to rapid degradation by the proteasome.

In the presence of PML, HIPK2 ubiquitination still happens, but degradation is prevented. PML, HIPK2 and FBXO3 may act synergically to trigger p53/TP53- dependent transactivation.