Enables identical protein binding activity. Acts upstream of or within negative regulation of calcineurin-NFAT signaling cascade; negative regulation of phosphoprotein phosphatase activity; and regulation of skeletal muscle adaptation. Located in costamere. Is expressed in heart; skeletal muscle; and somite. Orthologous to human CMYA5 (cardiomyopathy associated 5). [provided by Alliance of Genome Resources, Apr 2022]