Cytoplasmic Fibers in Mammalian Cells: Cytoskeletal and Contractile Elements

Cells derived from many types of nonmuscle tissues contain three classes of cytoplasmic fibers: microfilaments, 10 nm filaments, and microtubules. Since many excellent reviews have appeared recently on the subject of microtubules (see 63, 74, 130, 142, 174, 181, 198) we 'have chosen to emphasize the microfilament and 10 nm filament systems. Microtubules are discussed only with regard to their possible interactions with these systems. In order to narrow the scope of this review even further, we emphasize studies of normal mammalian cell systems and stress those investigations that relate structure to biochemical and molecular function.