Interacts with CMYA5 (By similarity). In cardiac muscles, identified in a complex composed of FSD2, CMYA5 and RYR2 (By similarity). In skeletal muscles and striated muscles flanks Z-disks (PubMed:28740084). Partially colocalizes with RYR2 in the sarcoplasmic reticulum (PubMed:28740084). Expressed in skeletal and cardiac muscles.