RECONSTITUTION OF ACTIVE MOVEMENT INVITRO BASED ON THE ACTIN MYOSIN INTERACTION

The development of the methods for observation of movement in vitro and results obtained with the in vitro motility assay are reviewed in the chapter. The interaction between actin and myosin is responsible for a variety of types of cell motility, such as amoeboid movement, cytoplasmic streaming, cytokinesis, exocytosis, and muscle contraction. Immunofluorescence microscopy with antibody to Dictyostelium myosin I and II provides evidence on their specific localization in the cell. These results are consistent with the motile behavior of a Dictyostelium mutant that has a myosin II deficiency. A genetic approach with mutagenesis is useful for investigating cell motility. Actin isoforms also exhibit a distinct distribution in microvascular pericyte cells. The globular head contains the adenosine triphosphatase (ATPase) activity and the activity of binding to a protein assembly, F-actin, or microtubule. This common structure of the molecular machine is significant for transduction from chemical to mechanical energy. The observations of movement in vitro of actin and myosin filaments by phase-contrast, dark-field, and fluorescence microscopy are also presented in the chapter. © 1991 Academic Press Inc.