6: The Cytoskeleton
- Page ID
- 173532
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)We often think of the many pathways of the cytoskeleton as “the highways of the cell,” yet the reality is so much more complex and fascinating. They do not simply act as highways but highways that can disassemble and completely rebuild themselves when the need arises. Throughout the previous chapters of this book, we have made reference to the cytoskeleton and its role in the various cellular processes. This is because the cytoskeleton is involved in virtually every aspect of cellular function. It’s impossible to ignore the central role the cytoskeleton plays in the cell. The cytoskeletal “highways” help provide structure and connection within the cell and between cells. The cytoskeleton influences the shape of the cell and aids in the relay of signals from one part of the cell to another. The cytoskeleton helps cells grow, move, retract, and even die. We can see the impact of the cytoskeleton in every chapter you’ve read thus far, and it will continue to play an important role in the remaining chapters.
In this chapter, we will explore the components of the cytoskeleton, the details of how it is built, and how it functions. We will highlight some specific examples of function that are considered more universal, but know that there are so many more examples that could also be included.
- 6.1: Overview of the Cytoskeleton and Intermediate Filaments
- This page outlines the significant roles of intermediate filaments within the cytoskeleton, emphasizing their importance in cell shape, mechanical resilience, and tissue specificity. Intermediate filaments, such as keratins and neurofilaments, are vital for cellular integrity, supporting functions like structural organization in the nucleus and maintaining neuron shape.
- 6.2: Microtubules and Dynamic Instability
- This page details the dynamic nature of microtubules, protein polymers essential for cellular function, characterized by growth and shrinkage (dynamic instability). Composed of tubulin dimers, microtubules have distinct ends that affect their assembly and stability, influenced by GTP binding. Microtubule-organizing centers (MTOCs) facilitate growth, while accessory proteins regulate their dynamics.
- 6.3: Actin Filaments
- This page covers actin filaments, their dynamic instability, and the influence of actin-binding proteins (ABPs) on their organization and functions, especially in cellular motility and muscle contraction via myosin. It details various myosin types, their movement along actin, and their reliance on ATP for function.
- 6.4: End-of-Chapter Material
- This page discusses the cytoskeleton, focusing on three components: intermediate filaments, microtubules, and actin filaments. Intermediate filaments offer tensile strength, microtubules are hollow tubes important for dynamic stability and cellular processes, and actin filaments facilitate locomotion and transport. Additionally, review questions are included to enhance comprehension of these structures and their roles in cellular biology.
Thumbnail: This image is made from a Molecular Probes demo slide. (Public Domain; NIH via Wikipedia)