FBXL2

Calcium-activated substrate recognition component of the SCF (SKP1-cullin-F-box protein) E3 ubiquitin-protein ligase complex, SCF(FBXL2), which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:22020328, PubMed:22323446). Unlike many F-box proteins, FBXL2 does not seem to target phosphodegron within its substrates but rather calmodulin-binding motifs and is thereby antagonized by calmodulin (PubMed:22020328, PubMed:22323446). This is the case for the cyclins CCND2 and CCND3 which polyubiquitination and subsequent degradation are inhibited by calmodulin (PubMed:22020328, PubMed:22323446). Through CCND2 and CCND3 degradation induces cell-cycle arrest in G(0) (PubMed:22020328, PubMed:22323446). SCF(FBXL2) also mediates PIK3R2 ubiquitination and proteasomal degradation thereby regulating phosphatidylinositol 3-kinase signaling and autophagy (PubMed:23604317). PCYT1A monoubiquitination by SCF(FBXL2) and subsequent degradation regulates synthesis of phosphatidylcholine, which is utilized for formation of membranes and of pulmonary surfactant (By similarity). The SCF(FBXL2) complex acts as a regulator of inflammation by mediating ubiquitination and degradation of TRAF proteins (TRAF1, TRAF2, TRAF3, TRAF4, TRAF5 and TRAF6) (By similarity). The SCF(FBXL2) complex acts as a negative regulator of the NLRP3 inflammasome by mediating ubiquitination and degradation of NLRP3 (PubMed:26037928).