Two novel phosphorylation sites of myosin light chain 1 (MLC1) are
described. Methods of monitoring phosphorylation of MLC1 to identify new
cardiac and skeletal muscle protective agents, monitor the extent of
preconditioning of cardiac and skeletal muscles, and monitoring the status
of a subject with cardiac or skeletal muscle damage are provided. Also
provided are methods and compositions for altering MLC1 to change
contractility of cardiac and skeletal muscles and to protecting cardiac
and skeletal muscles from damage caused by conditions and/or agents
including, but not limited to, cardiomyopathies, hypertension, free
radicals ischemia, hypoxia, and ischemia/hypoxia with reperfusion.
