E-Mail Credit: Colleen Kelley/University of Cincinnati Researchers at the University of Cincinnati say a regulatory protein found in skeletal muscle fiber may play an important role in the body's fight or flight response when encountering stressful situations. The protein, fast skeletal myosin binding protein-C (fMyBP-C), plays a foundational role in the proper regulation of contractile structure and function in the body's fast twitch muscles -- these muscles produce sudden bursts of power to sprint into action, jump or lift heavy objects. Fast skeletal myosin binding protein-C modulates the speed and force of fast skeletal muscle contraction. "This response is very critical for the higher animal and human survival. Just imagine, you are walking through a forest and suddenly you see a tiger in front of you," says Sakthivel Sadayappan, PhD, a professor in the UC Division of Cardiovascular Health and Disease. "You will immediately act, either to fight or run away from the animal. For that action, fast muscle is essential, and fast myosin binding protein-C is the key molecule to regulate the speed of action."