Cell and Molecular Biology of the Cytoskeleton focuses on the three major fibrous proteins in the cytoplasm that are collectively known as the cytoskeletal sys tem. These polymorphic cytoskeletal proteins are microtubules (25-nm diam eter), microfilaments (6-nm diameter), and intermediate filaments (l O-nm diameter). Microtubules consist of tubulin and several well-characterized mi crotubule-associated proteins (MAPs) such as MAPl, MAP2, and tau. Micro filaments consist of actin and associate with actin-binding proteins, including alpha-actinin, filamin, myosin, tropomyosin, vinculin, and...