Myosin with two FERM domains in the tail region. It has an extended lever arm consisting of five calmodulin binding IQ motifs followed by a single alpha helix (SAH). Myosin VII is required for phagocytosis in "Dictyostelium discoideum", spermatogenesis in "C. elegans" and stereocilia formation in mice and zebrafish. Myosin VIII is a plant-specific myosin linked to cell division; specifically, it is involved in regulating the flow of cytoplasm between cells and in the localization of vesicles to the phragmoplast. Myosin IX is a group of single-headed motor proteins. It was first shown to be minus-end directed, but a later study
Alpha-keratin must be type I, while the other must be type II. Even within type I and II, there are acidic and basic keratins that are particularly complementary within each organism. For example, in human skin, K5, a type II alpha keratin, pairs primarily with K14, a type I alpha-keratin, to form the alpha-keratin complex of the epidermis layer of cells in the skin. Hard alpha-keratins, such as those found in nails, have a higher cysteine content in their primary structure. This causes an increase in disulfide bonds that are able to stabilize the keratin structure, allowing it to resist a