PC12 cells stimulate slow-myosin light chain 2 synthesis in chick breast muscle culture

Skeletal muscle fibers developing in vitro synthesize predominantly fast-myosin light chains, with a small contribution (less than 10%) from slow-myosin light chain 2. Muscle fibers can be cocultured with a rat adrenal pheochromocytoma-derived nerve cell line (PC12) known to display properties similar to sympathetic neurons. PC12 cells cultured alone synthesize catecholamines and respond to nerve growth factor by synthesizing acetylcholine and extending neurite structures. They also synthesize significant amounts of acetylcholine in the presence of nonneuronal cell types, including muscle. When cocultures of skeletal muscle fibers and PC12 cells are established, the muscle cells respond with an increased level of slow light chain 2 synthesis. Myosin light chains were identified by two-dimensional gel electrophoresis and immunoblotting with an antiserum specific to slow light chain 2.