Interacts with CMYA5 (PubMed:28740084). In cardiac muscles, identified in a complex composed of FSD2, CMYA5 and RYR2 (PubMed:28740084). In skeletal muscles and striated muscles flanks Z-disks. Partially colocalizes with RYR2 in the sarcoplasmic reticulum. Expressed predominantly in heart and skeletal muscle (at protein level). Truncated N-terminus.