Preface

Chapter 8 **Cytoskeleton Rearrangements during the Execution Phase of**

Chapter 9 **How are Dynamic Microtubules Stably Tethered to Human**

Chapter 10 **Muscle Fibers Lacking Desmin in the Extraocular Muscles: A**

Chapter 11 **The Actomyosin Network and Cellular Motility: A S100A4 Regulatory View into the Process 205**

Ariane Zamoner and Regina Pessoa-Pureur

Chapter 13 **Acting on Actin During Bacterial Infection 257**

Chapter 12 **Intermediate Filaments as a Target of Signaling Mechanisms in**

Chapter 14 **Heterotrimeric G Proteins and the Regulation of Microtubule**

Sukla Roychowdhury and Jorge A. Sierra-Fonseca

Chapter 15 **Novel Insights into the Role of the Cytoskeleton in Cancer 299**

Chapter 16 **Targeting the Cytoskeleton with Plant-Bioactive Compounds in**

Xuan Zhang, Zenglin Pei, Chunxia Ji, Xiaoyan Zhang, Jianqing Xu

Jesús Porcuna Doncel, Patricia de la Cruz Ojeda, Manuel Oropesa‐ Ávila, Marina Villanueva Paz, Isabel De Lavera, Mario De La Mata, Mónica Álvarez Córdoba, Raquel Luzón Hidalgo, Juan Miguel Suarez Rivero, David Cotán and José Antonio Sánchez‐Alcázar

Duccio Conti, Madeleine Hart, Naoka Tamura, Roshan Shrestha,

**Apoptosis 151**

**VI** Contents

**Chromosomes? 171**

**Paradigm Shift 197** Fatima Pedrosa Domellöf

Stephane R. Gross

**Neurotoxicity 233**

Elsa Anes

**Assembly 279**

and Jin Wang

**Cancer Therapy 315**

Anca Hermenean and Aurel Ardelean

Asifa Islam and Viji M. Draviam

**Section 2 Cytoskeleton: Function and Disease 195**

All cells of all domains of life (archaea, bacteria, and eukaryotes) contain constituents of the cytoskeleton, in which systems of different organisms are composed of similar proteins. However, the structure, function, and dynamic behavior of the cytoskeleton can be very dif‐ ferent, depending on organism and cell type. Even within one cell, the cytoskeleton can change through association with other proteins and the previous history of the network.

In eukaryotes, the cytoskeletal matrix is a dynamic structure integrated in three main pro‐ teins (microtubules, intermediate filaments, and actin filaments), which are capable of a fast growth or disassembly depending on the cell's requirements at a certain period of time. Un‐ derlying all this complexity is the knowledge that the cell is alive and is constantly changing its properties, actively, as a consequence of many external factors, by integrating environ‐ ment stimuli through different cell signaling pathways.

In recent years, it has been shown that bacteria contain a number of cytoskeletal structures and elements that include homologues of eukaryotic cytoskeletal proteins (actin, tubulin, and intermediate filament proteins) and a fourth group, the MinD-ParA group, which ap‐ pears to be unique to bacteria.

The cytoskeleton is the overall name given to protein filaments and motor proteins in the cell, which form a massive and dynamic three-dimensional (3D) scaffolding structure, driv‐ ing cell shape and cell organization, in determining the spatial arrangement of membrane receptors and thus in the development of cell polarity, movement, and cell stability. It plays a crucial role in many fundamental processes of cell growth and development such as chro‐ mosome segregation during cellular division and cytokinesis (the division of a mother cell into two daughter cells), cell expansion, and intracellular organization, also contributing to the organelles' functionality.

Furthermore, filaments can be cross-linked to other similar filaments and to membranes, having accessory and/or actin-binding proteins as intermediaries. This interlinking signifi‐ cantly increases rigidity, as the time that some filaments are used as trackways for motor proteins to transport molecules and cargo-containing vesicles around the cell and the uptake of extracellular material (endocytosis).

Many proteins of the cytoskeleton have been newly identified and have tentative functions assigned, and recently deficiencies were identified in disease states. In addition, components of the cytoskeleton form specialized structures, such as flagella, cilia, sperm, lamellipodia, and podosomes, allowing cells to move, cell organelles to be moved and positioned along the protein filaments using them as roadways rather like how a railway locomotive runs on rail tracks, and muscles to function.

The cytoskeleton is of fundamental importance in a wide range of cellular processes and that an appreciation of its features and functions impacts on a wide range of cell physiology, spanning research from fundamental cell biology to cancer pathology. We believe that knowledge of the cytoskeleton will be of benefit to a large number of physiologists, bio‐ chemists, and medical students as well as cell and molecular biologists.

Until recently, the emphasis in cytoskeleton research has been on identification of protein components and structural studies of the proteins and to stress functional aspects of the cy‐ toskeleton and how this may be related to cell and tissue physiology and to disease.

This chapter presents the preface to cytoskeletal advances in structure, functional dynamics, and disease. It discusses protein structure-composition of the major filament systems (microfi‐ laments, microtubules, and intermediate filaments) and major cytoplasmic components (actin and tubulin, the monomeric constituents of microfilaments and microtubules, are major cell proteins), which play important roles in cell function, and investigations into the functional role of the cytoskeleton currently represent a major area of cell biological research.

We would like to thank the authors for writing these interesting articles.

**Jose C. Jimenez-Lopez, Ph.D.** Spanish National Research Council (CSIC) Estacion Experimental del Zaidin (EEZ) Department of Biochemistry, Cell and Molecular Biology of Plants, Spain **Cytoskeleton: Structure and Dynamics**

The cytoskeleton is of fundamental importance in a wide range of cellular processes and that an appreciation of its features and functions impacts on a wide range of cell physiology, spanning research from fundamental cell biology to cancer pathology. We believe that knowledge of the cytoskeleton will be of benefit to a large number of physiologists, bio‐

Until recently, the emphasis in cytoskeleton research has been on identification of protein components and structural studies of the proteins and to stress functional aspects of the cy‐

This chapter presents the preface to cytoskeletal advances in structure, functional dynamics, and disease. It discusses protein structure-composition of the major filament systems (microfi‐ laments, microtubules, and intermediate filaments) and major cytoplasmic components (actin and tubulin, the monomeric constituents of microfilaments and microtubules, are major cell proteins), which play important roles in cell function, and investigations into the functional role

**Jose C. Jimenez-Lopez, Ph.D.**

Spain

Spanish National Research Council (CSIC) Estacion Experimental del Zaidin (EEZ)

Department of Biochemistry, Cell and Molecular Biology of Plants,

toskeleton and how this may be related to cell and tissue physiology and to disease.

chemists, and medical students as well as cell and molecular biologists.

VIII Preface

of the cytoskeleton currently represent a major area of cell biological research. We would like to thank the authors for writing these interesting articles.
