The Actin Cytoskeleton In Cell Motility Cancer And Infection

The cell is no longer considered to be a bag full of enzymes dissolved in a liquid cytoplasm. It is now known that the cytoplasm is an exquisitely ordered structure of properly placed organelles and enzyme complexes that are suspended from an intricate network of structural protein polymers termed the cytoskeleton. All movement of organelles and vesicles within the cell is regulated by this cytoskeleton, and it is clear that the cytoskeleton is responsible for all of the cell's external movement as well. In this lecture, we will consider how the cytoskeleton elicits cell migration.The three main elements of the cytoskeleton are microtubules, intermediate filaments, and actin filaments. Microtubules are essential for (a) intracellular transport within the cytoplasm and transport between the nucleus and cytoplasm, (b) the structure and movement of all cilia and flagella, and (c) the structure of the mitotic spindle and movement of chromosomes on the spindle during cell division. Intermediate filaments give structural integrity to virtually all cells and tissues by providing an intracellular network of flexible cables that strengthen internal cell structure and stabilize cell-to-cell adhesion. It is this intercellular binding property that stably joins epithelial cells together to provide the protective functions of skin and the integrity of the intestinal mucosa.Actin is a highly conserved protein ubiquitous to all eukaryotic cells. Actin is absolutely required for (a) cell migration, (b) the contraction of muscle (both striated and smooth), (c) the structure and function of many cell protrusions (e.g., microvilli, filopodia, lamellopodia, blood platelet projections), (d) division of the cytoplasm (cytokinesis) during telophase of cell mitosis, and (e) movement and placement of organelles within the cell. Actin filaments are also called thin filaments because of their very slender (70 Ã…) diameter.

This volume addresses the structural and functional roles of the cytoskeleton and its dysfunctions which often lead to disease. It provides thorough discussion of microtubules, microfilaments, intermediate filaments, and cytoskeletal functions and dysfunctions in different organ systems. Comprehensive yet concise. The Cytoskeleton In Health And Disease presents cutting-edge discoveries balanced with background information and highlights the new aspects of the research and its impact on the design of new strategies or the identification of new targets for therapeutic intervention. There is a significant need for a book on this topic, as interest in the cytoskeleton continues to grow as causes and cures for cytoskeletal diseases are further explored in biomedical research. This book is essential reading for scientists, students, and teachers interested in expanding their knowledge related to the cytoskeleton. New researchers entering the field will find classic and well as contemporary information not easily found in the current literature or internet resources.

Actin is one of the most abundant proteins and ubiquitously expressed in all eukaryotes. In recent years, the analysis of structure and function of such complexes has shed new light on actin's role in cellular and tissue morphogenesis, locomotion and various forms of intracellular motility, but also on its role in nuclear processes like chromatin architecture and transcription. Progress in understanding these different physiological phenomena, but also in unravelling the basis of actin-based pathophysiological processes has been made by combining video microscopy, molecular biology, genetics and biochemistry. Thus, the current research on actin, as ongoing in many international laboratories, is a "hot spot" in basic and translational research in life sciences. In this book on "The Actin Cytoskeleton", twelve internationally renowned authors present specific chapters that cover their recent work concerned with the various roles of actin mentioned above. This comprehensive volume is therefore an attractive handbook for teachers and students in many fields of medicine and pharmacology.

Actin Cytoskeleton in Cancer Progression and Metastasis - Part A, Volume 355 in the International Review of Cell and Molecular Biology series, provides an overview of the roles of the actin cytoskeleton and some of its key structural regulators, including WASp, Paxillin, Myosin, Testin, L-Plastin and profilin, in central processes underlying cancer progression and metastasis, such as changes in cell morphology and gene expression, acquisition of migratory and invasive capabilities, and evasion from the immune response. Provides comprehensive and timely reviews on actin cytoskeleton and its regulators in cancer biology Offers a wide range of perspectives for basic and translational research Discusses opportunities and challenges for translating knowledge of tumor cell actin cytoskeleton into clinical applications

The cytoskeleton is a highly dynamic intracellular platform constituted by a three-dimensional network of proteins responsible for key cellular roles as structure and shape, cell growth and development, and offering to the cell with "motility" that being the ability of the entire cell to move and for material to be moved within the cell in a regulated fashion (vesicle trafficking). The present edition of Cytoskeleton provides new insights into the structure-functional features, dynamics, and cytoskeleton's relationship to diseases. The authors' contribution in this book will be of substantial importance to a wide audience such as clinicians, researches, educators, and students interested in getting updated knowledge about molecular basis of cytoskeleton, such as regulation of cell vital processes by actin-binding proteins as cell morphogenesis, motility, their implications in cell signaling, as well as strategies for clinical trial and alternative therapies based in multitargeting molecules to tackle diseases, that is, cancer.

The actin cytoskeleton has been studied for more than fifty years now. Ample studies have documented its fundamental role in cell motility and migration and, especially in the last two decades, tremendous progress has been made to understand the biochemistry of this complex system in relation to its cellular function. The actin system is a multipurpose machine for the cell and is essential for virtually all cellular processes. The actin cytoskeleton is an architectural element, it generates the force for cell migration and for muscle contraction, it is involved in endocytosis, and filaments serve as tracks for sorting cellular components. In the various chapters of this book the role of the actin cytoskeleton in these very different cellular processes is described. As a consequence of its multitasking function, abnormalities in this essential structural component frequently result in disease. Mutations and deregulation of cytoskeletal proteins cause a wide variety of disorders, including muscle and cardiac myopathies, neuronadegenerative diseases and cancer. The first three chapters deal with various molecular properties of components of the actin cytoskeleton in relation to cellular function (and dysfunction). In Chapter 1 Vandamme and coworkers discuss the major building block of the actin cytoskeleton, the actin molecule itself. The paper focuses on gene structures and the tissue and developmental regulation of the six mammalian actin isoforms. Mutations in the actin molecule leading to diseases are discussed as are pathophysiological situations connected to particular actin isoforms. In Chapter 2 the group of Prof. Hüttelmaier gives an overview of an emerging field in actin cytoskeleton research; that of subcellular sorting of the cytoplasmic actin isoforms and its role in establishing polarity via posttranscriptional control of gene expression. Intriguing is the dual property of actin in this, it functions as a track and anchoring scaffold for its own synthesis. In a next chapter by Veniere et al. the biochemistry of actin and actin binding proteins is summarized and put into a context of the formation of subcellular structures, lamellipodia, filopodia and stress fibers, typically associated with cell migration. In the last decade, the actin cytoskeleton also gained clinical importance with the growing awareness of its crucial role during deregulated tumor cell invasion. Therefore two chapters are entirely devoted to the actin cytoskeleton in cancer cell migration. In Chapter 4 Prof. Roy and his team describe the deregulations in the actin system leading to tumor cell migration, expanding on the regulation by Rho-GTPases and polyphosphoinositides. In Chapter 5, Debeir and colleagues outline the rationales for using particular tools to study cell migration assays and discusses, in-depth, global and single cell assays, microscopy and image acquisition technologies, and software tools to study the migratory behavior of cancer cells in in vitro and in vivo model systems. The next four chapters focus on specialized systems. In Chapter 6 Prof. Dent updates on progress made on the role of the actin cytoskeleton in the differentiation of neurons including neuronal migration through axon outgrowth and guidance to synaptogenesis. In Chapter 7, Dr. Sonnemann and Prof. Ervasti, revisit some actin isoforms for their role in muscle development and formation of substructures that are typical for muscle cells and also describe actin diseases in skeletal and cardiac muscle. Dr. Hinz describes, in Chapter 8, the intricate relation between the (maturing) adhesion machinery and the actin cytoskeleton, its role in mechanosensing and in transmitting mechanical stress signals. An equally complex interplay exists between the actin cytoskeleton and the plasma membrane. Prof. Qualmann and coworkers discuss this in the final chapter giving an extensive overview of multidisciplinary research that has advanced our understanding on the cellular pathways and coordinated events leading to formation of vesicles, in which the actin cytoskeleton is instrumental. We acknowledge all authors for their expert contributions. No book of this size on the actin cytoskeleton can be complete, but with this book we have covered a large part of the current research directions in this field. As is evident from the concluding remarks in each of the chapters our work for understanding the role of the actin cytoskeleton is far from complete. Despite many years of intensive and elegant research, many intriguing questions remain but we hope by publishing this book we incite (young) scientists to take up research in the wonderful world of the actin cytoskeleton.