Since the discovery of actin by Straub in the 1950’s and the pioneering work of Oosawa on actin self-assembly in helical laments in the 1960’s, many books and conference proceedings have been published. As one of the most essential p- teins in life, essential for movement in organisms rangingfrom bacteria to higher eukaryotes, it is no surprise that actin has fascinated generations of scientists from many different elds. Actin can be considered as a “living treasure” of biology; the kinetics and thermodynamics of self-assembly, the dissipative nature of actin po- merization, the molecular interactions of monomeric and polymerized actin with regulators, the mechanical properties of actin gels, and more recently the force p- ducing motile and morphogenetic processes organized by the actin nanomachine in response to signaling, are all milestones in actin research. Discoveries that directly derive from and provide deeper insight into the fundamental properties of actin are constantly being made, making actin an ever appealing research molecule. At the same time, the explosion in new technologies and techniques in biological sciences has served to attract researchers from an expanding number of disciplines, to study actin. This book presents the latest developments of these new multiscale approaches of force and movement powered by self-assembly processes, with the hope to opening our perspectives on the many areas of actin-based motility research.

Shigellosis is present all over the world. Anyone traveling in developing countries knows that the control of this invasive disease of the intestine is a priority task for physicians and public health authorities. Victims are essentially young children, and complications such as the hemolytic uremic syndrome make shigellosis a systemic disease rather than simply an infection of the colonic mucosa. However, "Westerners" should not consider shigeJlosis as an unlikely threat of the tropics. The disease arises in industrialized countries as soon as breaches in sanitation appear. A few months ago, at least 500 people developed shigellosis in northern France in an outbreak of Shigella sonnei infection due to accidental contamination of an urban water delivery system. The pathogenesis of shigellosis is an extraordinary topic of research because study of the invasion of the colonic mucosa addresses fundamental questions on. the molecular and cellular mechanisms by which a bacterial pathogen can pene trate non phagocytic cells, survive, multiply, spread in the intra cellular compartment, and eventually kill host cells. Further development of the infection within subepithelial tissues as well as the mechanisms that contribute to the eradication of this process have barely been studied.

In recent years remarkable progress has been accomplished with respect to our knowledge about bacterial protein toxins. This refers especially to structural aspects of protein toxins but also holds true for genetics, molecular biology and biochemical mechanisms underlying the action of toxins. This volume covers the very current and exciting aspects of up-to-date bacterial toxicology and comprehensively reviews the most important bacterial protein toxins such as the intracellular acting toxins which exhibit enzyme activity, as well as those toxins that interact with cell plasma membranes by damaging the membranes (pore formation) or stimulating cell receptors (superantigens). This is the most current reference work on these important bacterial protein toxins, which are presented from the point of view of different disciplines such as pharmacology, microbiology, cell biology and protein chemistry.

This monograph explores the relationships between cell signaling and the cytoplasmic cytoskeleton in fundamental cell processes, thus bridging the gap between two very active aspects of molecular cell biology. It covers the two main - and reciprocal - questions of these relationships: How are structure and function of the cytoskeleton affected by external signals which impinge on the cell? How does the cytoskeleton influence the cellular signaling processes which determine cell behavior?