Basic Properties of the Actin Molecule and Actin-Based Microfilament Systems.- Vibrational Modes of G-Actin.- Combining Electron Microscopy and X-Ray Crystallography Data to Study the Structure of F-Actin and its Implications for Thin-Filament Regulation in Muscle.- Evidence for an F-Actin Like Conformation in the Actin: DNase I Complex.- Actin-Bound Nucleotide/Divalent Cation Interactions.- Influence of the High Affinity Divalent Cation on Actin Tryptophan Fluorescence.- C-Terminus on Actin: Spectroscopic and Immunochemical Examination of its Role in Actinomycin Interactions.- Actin Polymerization: Regulation by Divalent Metal Ion and Nucleotide Binding, ATP Hydrolysis and Binding of Myosin.- Actin-Associated Proteins and Control of Filament-Based Assembly-Disassembly.- Structural Requirements of Tropomyosin for Binding to Filamentous Actin.- Actin-Gelsolin Interaction.- Actin Regulation and Surface Catalysis.- Caldesmon: Possible Functions in Microfilament Reorganization During Mitosis and Cell Transformation.- Cytoskeleton, Motile Structures and Macromolecular Crowding.- Cellular Functions of the Microfilament System.- Actin Filament Dynamics in Cell Motility.- Changes in Adhesion Plaque Protein Levels Regulate Cell Motility and Tumorigenicity.- Induction of Collagen Synthesis in Response to Adhesion and TGF? is Dependent on the Actin-Containing Cytoskeleton.- Gelsolin Expression in Normal Human Keratinocytes is a Function of Induced Differentiation.- Actin Filaments and the Spatial Positioning of mRNA.- Redistribution of p52(PAI-l) mRNA to the Cytoskeletal Framework Accompanies Increased p52(PAI-l) Expression in Cytochalasin D-Stimulated Rat Kidney Cells.- Brush Border Myosin I Has a Calmodulin/Phosphatidylserine Switch and Tail Actin-Binding.- Control of p52(PAI-l) Gene Expression in Normal and Transformed Rat Kidney Cells: Relationship Between p52(PAI-l) Induction and Actin Cytoarchitecture.- Contributors.