Microfilament-Membrane Interactions in Cell Shape and Surface Architecture

Abstract

Since the first conference on cell motility in 1963 (Allen and Kamiya) substantial evidence has been acquired that sliding interactions between myosin and filaments of actin power many forms of motility exhibited by eucaryotic cells such as muscle contraction, amoeboid movement, cytoplasmic streaming, changes in cell shape, saltatory particle movement, redistribution of cell surface components, endocytosis and exocytosis (Taylor and Condeelis 1979; Condeelis 1980). A logical and necessary assumption in how sliding interactions between actin and myosin move the cell and its components is that either one or both of these proteins must be attached to cell membranes. A brief survey of the literature for examples of microfilament-membrane interactions provides both biochemical (Wickus et al. 1975; Weihing 1976; Ceccarini et al. 1978; Spudich 1974; Koch and Smith 1978; Condeelis 1979) and morphological (Pollard and Korn 1973; Mooseker and Tilney 1975; Schroeder 1973; Goldman et al. 1976; Begg et al. 1978; Condeelis 1979; Salisbury et al. 1980) evidence that such interactions occur. It is also clear from these studies that microfilamentmembrane interactions occur with differences in morphology and stability that are probably significant for the function of these structures. These differences also suggest that there may be multiple mechanisms by which microfilament-membrane interactions occur although as yet none of these mechanisms have been elucidated.