Involved in skeletal muscle excitation/contraction coupling (EC), probably acting as a regulator of the voltage-sensitive calcium channel CACNA1S. EC is a physiological process whereby an electrical signal (depolarization of the plasma membrane) is converted into a chemical signal, a calcium gradient, by the opening of ryanodine receptor calcium release channels. May regulate CACNA1S membrane targeting and activity. . This is the function of JSRP1 (junctional sarcoplasmic reticulum protein 1, ENSG00000167476).