Cullin-5 (CUL5)

Core component of multiple SCF-like ECS (Elongin-Cullin 2/5-SOCS-box protein) E3 ubiquitin-protein ligase complexes, which mediate the ubiquitination and subsequent proteasomal degradation of target proteins. As a scaffold protein may contribute to catalysis through positioning of the substrate and the ubiquitin- conjugating enzyme.

The functional specificity of the E3 ubiquitin-protein ligase complex is based upon the variable substrate recognition component. ECS(SOCS1) appears to direct ubiquitination of JAK2.