A structural constituent of muscle. Acts upstream of or within muscle organ development. Located in Z disc; junctional sarcoplasmic reticulum membrane; and plasma membrane. Part of junctional membrane complex. Is expressed in heart and skeletal muscle. Human ortholog(s) of this gene implicated in Charcot-Marie-Tooth disease axonal type 2K. Orthologous to human JPH1 (junctophilin 1). [provided by Alliance of Genome Resources, Apr 2022]