Plays an important role in the process of myofiber differentiation and maturation. Probable substrate-recognition component of a SCF-like ECS (Elongin BC-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of proteins. Probably contributes to catalysis through recognition and positioning of the substrate and the ubiquitin-conjugating enzyme. During myogenesis, controls the ubiquitination and degradation of the specific pool of CTNNB1/beta-catenin located at the sarcolemma (By similarity). Protein modification; protein ubiquitination. Probable component the ECS(NEURL2) E3 ubiquitin-protein ligase complex consisting of ELOB/Elongin B, ELOC/Elongin C, CUL5, RBX1 and NEURL2. Interacts with CTNNB1 (By similarity). Expressed specifically in skeletal and cardiac muscles. The SOCS domain mediates the interaction with ELOB and ELOC, while the NHR domain may be involved in ubiquitination substrate binding.