What is the name of the protein that forms thin filaments?

The protein that forms thin filaments is actin. Actin is a globular protein that polymerizes to form long chains or filaments, known as F-actin, which are key components of the cytoskeleton in cells and play a critical role in muscle contraction. In skeletal muscle, actin filaments interact with myosin filaments to enable contraction through the sliding filament mechanism, where the thick myosin filaments pull the thin actin filaments towards the center of the sarcomere.

Understanding the structure and function of actin is essential in the study of muscle physiology and various cellular processes, including movement, shape maintenance, and cell division. The significance of actin lies not just in muscle tissue but also in non-muscle cells, as it is involved in many cellular activities, including motility and maintaining cell structure.