Overview Examples actin Structure helical polymers of G-actin has polarity login to view 2 more bullets "treadmilling" formation requires ATP dynamic structure that is constantly forming and breaking down login to view 1 more bullet G-actin has intrinsic ATPase capabilities Function can interact with myosin to mediate contractile forces mediate motile forces mediate cytokinesis can interact with cell membrane to form core of microvilli login to view 1 more bullet anchor tight junctions anchor zonula adherens