Substrate-recognition component of a SCF-like ECS (Elongin-Cullin-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:16325183, PubMed:15590664). Mediates Notch-induced ubiquitination and degradation of substrates including TCF3/E2A and JAK2 (PubMed:21119685). Required during embryonic heart development for complete heart looping (By similarity). Required for cardiomyocyte differentiation (PubMed:32179481). Involved in myogenic differentiation and targets filamin FLNB for proteasomal degradation but not filamin FLNA (PubMed:19300455). Also targets DES for proteasomal degradation (By similarity). Acts as a negative regulator of skeletal muscle mass (By similarity). Targets filamins FLNA and FLNB for proteasomal degradation (PubMed:21737450, PubMed:22916308, PubMed:24044920, PubMed:24052262). This leads to enhanced adhesion of hematopoietic cells to fibronectin (PubMed:21737450). Required for FLNA degradation in immature cardiomyocytes which is necessary for actin cytoskeleton remodeling, leading to proper organization of myofibrils and function of mature cardiomyocytes (By similarity). Required for degradation of FLNA and FLNB in immature dendritic cells (DC) which enhances immature DC migration by promoting DC podosome formation and DC-mediated degradation of the extracellular matrix (By similarity). Does not promote proteasomal degradation of tyrosine-protein kinases JAK1 or JAK2 in hematopoietic cells (PubMed:22916308). Protein modification; protein ubiquitination. Component of a probable ECS E3 ubiquitin-protein ligase complex which contains CUL5, either RBX1 or RNF7/RBX2, Elongin BC complex (ELOB and ELOC) and ASB2 (PubMed:15590664, PubMed:16325183, PubMed:19300455, PubMed:24044920, PubMed:21119685). Interacts with SKP2 (PubMed:21119685). Through its interaction with SKP2, likely to bridge the formation of dimeric E3-ubiquitin-protein ligase complexes composed of an ECS complex and an SCF(SKP2) complex (PubMed:21119685). Interacts with JAK2; the interaction targets JAK2 for Notch-mediated proteasomal degradation (PubMed:21119685). Interacts with TCF3/E2A; the interaction is mediated by SKP2 and targets TCF3 for Notch-mediated proteasomal degradation (PubMed:21119685). Interacts with DES. Localizes to the Z line in cardiomyocytes. Expressed in muscle cells. Expressed in hematopoietic cells. Induced by all-trans retinoic acid (ATRA) (PubMed:11566180, PubMed:11682484). Induced by Notch signaling (PubMed:21119685). Repressed by microRNA miR-29c (PubMed:29955039). The SOCS box domain mediates the interaction with the Elongin BC complex, an adapter module in different E3 ubiquitin-protein ligase complexes. Both the N-terminus and ANK repeats 1 to 10 are necessary for interaction with filamins. The UIM domain is required for monoubiquitination. Monoubiquitinated. Not monoubiquitinated. Phosphorylation at Ser-371 is required for association with FLNA and subsequent FLNA degradation. Belongs to the ankyrin SOCS box (ASB) family.