The MYOT gene provides instructions for making a protein called myotilin. Myotilin is found in heart (cardiac) muscle and muscles used for movement (skeletal muscle). Within muscle fibers, myotilin proteins are found in structures called sarcomeres, which are necessary for muscles to tense (contract). Myotilin attaches (binds) to other proteins to help form sarcomeres. Myotilin is also involved in linking neighboring sarcomeres to each another to form myofibrils, the basic unit of muscle fibers. The connection of sarcomeres to each other and the formation of myofibrils are essential for maintaining muscle fiber strength during repeated cycles of contraction and relaxation.