Core component of multiple cullin-RING-based ECS (ElonginB/C- CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complexes, which mediate the ubiquitination of target proteins (PubMed:
11384984, PubMed:
26138980, PubMed:
29779948, PubMed:
29775578). CUL2 may serve as a rigid scaffold in the complex and may contribute to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme (PubMed:
9122164, PubMed:
10973499, PubMed:
11384984, PubMed:
12609982, PubMed:
24076655). The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit and is inhibited by the association of the deneddylated cullin subunit with TIP120A/CAND1 (PubMed:
12609982, PubMed:
24076655, PubMed:
27565346). The functional specificity of the ECS complex depends on the substrate recognition component (PubMed:
9122164, PubMed:
10973499, PubMed:
26138980, PubMed:
29779948, PubMed:
29775578). ECS(VHL) mediates the ubiquitination of hypoxia-inducible factor (HIF) (PubMed:
9122164, PubMed:
10973499). A number of ECS complexes (containing either KLHDC2, KLHDC3, KLHDC10, APPBP2, FEM1A, FEM1B or FEM1C as substrate-recognition component) are part of the DesCEND (destruction via C-end degrons) pathway, which recognizes a C-degron located at the extreme C terminus of target proteins, leading to their ubiquitination and degradation (PubMed:
26138980, PubMed:
29779948, PubMed:
29775578). ECS complexes and ARIH1 collaborate in tandem to mediate ubiquitination of target proteins (PubMed:
27565346).
