Probable substrate-recognition component of a SCF-like ECS (Elongin-Cullin-SOCS-box protein) E3 ubiquitin ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Recognizes type II iodothyronine deiodinase/DIO2. Confers constitutive instability to HIPK2 through proteasomal degradation. Protein modification; protein ubiquitination. Interacts with DIO2. Component of the probable ECS(WSB1) E3 ubiquitin ligase complex which contains CUL5, RNF7/RBX2, Elongin BC complex and WSB1. Component of a probable ECS-like E3 ubiquitin-protein ligase complex which contains CUL5, RBX1, Elongin BC complex and WSB1. Interacts with CUL5, RNF7, ELOB and ELOC. Binds to HIPK2 through WD40 repeats. The SOCS box domain mediates the interaction with the Elongin BC complex, an adapter module in different E3 ubiquitin ligase complexes.