SPRY domain-containing SOCS box protein 4

Substrate recognition component of a SCF-like ECS (Elongin BC-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Negatively regulates nitric oxide (NO) production and limits cellular toxicity in activated macrophages by mediating the ubiquitination and proteasomal degradation of NOS2. Acts as a bridge which links NOS2 with the ECS E3 ubiquitin ligase complex components ELOC and CUL5. Diminishes EphB2-dependent cell repulsive responses by mediating the ubiquitination and degradation of EphB2/CTF2. Regulates cellular clock function by mediating the ubiquitin/proteasome-dependent degradation of the circadian transcriptional repressor NR1D1.