Probable substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex that may function in myogenesis. Directly interacts with SKP1 and CUL1. Expressed only in heart and skeletal muscle. The expression decreases in the dystrophic muscle of Limb-girdle muscular dystrophy (LGMD) patient. Extended N-terminus.