Component of the dystrophin-glycoprotein complex (DGC), a complex that spans the muscle plasma membrane and forms a link between the F-actin cytoskeleton and the extracellular matrix. Preferentially associates with the sarcoglycan subcomplex of the DGC.
Subcellular locations: Cell membrane, Cell membrane, Sarcolemma, Postsynaptic cell membrane
Also found in myotendinous junctions and in the postsynaptic membrane of neuromuscular junctions.
Isoform 1 is expressed exclusively in heart and skeletal muscle. Isoform 2 is expressed in heart, skeletal muscle, thymus, prostate, testis, ovary, small intestine, colon and spleen.