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:15590664, PubMed:16325183). 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). Specifically promotes the ubiquitination of SMAD9 and targets it for proteasomal degradation, leading to avoid excessive accumulation of SMAD9 (PubMed:34845242). Plays a role in the regulation of NK-cell migration by modulating protein levels of filamin A/FLNA via regulation of its ubiquitination and proteasome degradation (By similarity). {ECO:0000250|UniProtKB:Q8K0L0, ECO:0000269|PubMed:15590664, ECO:0000269|PubMed:16325183, ECO:0000269|PubMed:21119685, ECO:0000269|PubMed:32179481, ECO:0000269|PubMed:34845242}. [Isoform 1]: 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). {ECO:0000250|UniProtKB:Q8K0L0, ECO:0000269|PubMed:19300455}. [Isoform 2]: 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). {ECO:0000250|UniProtKB:Q8K0L0, ECO:0000269|PubMed:21737450, ECO:0000269|PubMed:22916308, ECO:0000269|PubMed:24044920, ECO:0000269|PubMed:24052262}. This is the function of ASB2 (ankyrin repeat and SOCS box containing 2, Ensembl gene identifier ENSG00000100628).