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 depends on the variable substrate recognition component. ECS(SOCS1 seems to direct ubiquitination of JAK2. ECS(KLHDC1 complex is part of the DesCEND (destruction via C-end degrons pathway and mediates ubiquitination and degradation of truncated SELENOS selenoprotein produced by failed UGA/Sec decoding，which ends with a glycine. May form a cell surface vasopressin receptor.