Myosin to muscle cells (hence "myo-"(s) + "-in"), there is no single "myosin"; rather it is a very large superfamily of genes whose protein products share the basic properties of actin binding, ATP hydrolysis (ATPase enzyme activity), and force transduction. Virtually all eukaryotic cells contain myosin isoforms. Some isoforms have specialized functions in certain cell types (such as muscle), while other isoforms are ubiquitous. The structure and function of myosin is globally conserved across species, to the extent that rabbit muscle myosin II will bind to actin from an amoeba. Most myosin molecules are composed of a head, neck, and tail
Alpha-keratin disassemble into non-filamentous keratin precursors that can diffuse throughout the cell cytoplasm. These keratin filaments will be able to be used in future keratin synthesis, either to re-organize the final structure or create a different keratin complex. When the cell has been filled with the correct keratin and structured correctly, it undergoes keratin stabilization and dies, a form of programmed cell death. This results in a fully matured, non-vascular keratin cell. These fully matured, or cornified, alpha-keratin cells are the main components of hair, the outer layer of nails and horns, and the epidermis layer of the skin. The property