Enables protein homodimerization activity. Involved in negative regulation of calcium ion import into sarcoplasmic reticulum. Acts upstream of or within several processes, including negative regulation of calcium ion binding activity; regulation of calcium ion transport; and regulation of heart contraction. Located in sarcoplasmic reticulum membrane. Is expressed in several structures, including alimentary system; ear; heart; nervous system; and skeleton. Used to study centronuclear myopathy and dilated cardiomyopathy 1P. Human ortholog(s) of this gene implicated in dilated cardiomyopathy 1P and hypertrophic cardiomyopathy 18. Orthologous to human PLN (phospholamban). [provided by Alliance of Genome Resources, Apr 2022]