Download - Copyright (c) by W. H. Freeman and Company Chapter 18 Cell Motility and Shape I: Microfilaments
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Chapter 18
Cell Motility and Shape I: Microfilaments
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18.1 The actin cytoskeleton
Actin filaments (or microfilaments) are one of the three protein filament systems that comprise the cytoskeleton
Eukaryotic cells contain abundant amounts of highly conserved actin
Figure 18-1
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18.1 ATP holds together the two lobes of the actin monomer
Figure 18-2a
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18.1 G-actin assembles into long, helical F-actin polymers
Figure 18-2b,c
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18.1 The actin cytoskeleton is organized into bundles and networks of filaments
Figure 18-4
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18.1 Actin cross-linking proteins bridge actin filaments to form bundles and networks
Figure 18-5
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18.1 Cortical actin networks are connected to the plasma membrane: erythrocytes
Figure 18-7
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18.1 During blood clotting, platelets change shape due to changes in the actin cytoskeleton
Figure 18-8
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18.1 Cross-linkage of actin filament networks to the plasma membrane in various cells
Figure 18-9
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18.1 Actin bundles support projecting fingers of membrane
Figure 18-10
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18.2 Actin polymerization in vitro proceeds in three steps
Figure 18-11
Animação
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18.2 Actin filaments grow faster at one end that at the other
Figure 18-13
Several toxins can disrupt the actin monomer-polymer equilibrium
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18.2 Actin polymerization is regulated by proteins that bind G-actin
Figure 18-15a,b
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18.2 Many movements are driven by actin polymerization
The acrosome reaction in echinoderm sperm
Figure 18-17
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18.2 Movement of intracellular bacteria and viruses depends on actin polymerization
Figure 18-18
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18.2 Actin polymerization at the leading edge of moving cells
Figure 18-19
Actin Dinamics in moving cells
Actin in Lamelipodia Movements
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18.3 Myosin: the actin motor protein
All myosins have head, neck, and tail domains with distinct functions
Figure 18-20
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18.3 Functions of the myosin tail domain
Figure 18-21
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18.3 Myosin heads walk along actin filaments
Figure 18-22
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18.3 Myosin and kinesin share the Ras fold with certain signaling proteins
Figure 18-24
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18.3 Conformational changes in the myosin head couple ATP hydrolysis to movement
Figure 18-25
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18.4 Muscle: a specialized contractile machine
Figure 18-26
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18.4 Skeletal muscle contains a regular array of actin and myosin
Figure 18-27
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18.4 Capping proteins stabilize the ends of actin thin filaments in the sarcomere
Figure 18-28
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18.4 Thick and thin filaments slide past one another during contraction
Figure 18-29
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18.4 Titin and nebulin filaments organize the sarcomere
Figure 18-30
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18.4 A rise in cytosolic Ca2+ triggers muscle contraction (part I)
Figure 18-31a
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18.4 A rise in cytosolic Ca2+ triggers muscle contraction (part II)
Figure 18-31b
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18.4 Tropomyosin and troponin regulate contraction in skeletal muscle
Figure 18-32
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18.4 Ca2+-dependent mechanisms for regulating contraction in skeletal and smooth muscle
Figure 18-33
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18.4 Myosin-dependent mechanisms also control contraction in some muscles
Figure 18-34
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18.5 Actin and myosin II are arranged in contractile bundles that function in cell adhesion
Figure 18-35
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18.5 Myosin II stiffens cortical membranes
Figure 18-36
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18.5 Actin and myosin II have essential roles in cytokinesis
Figure 18-37
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18.6 Controlled polymerization and rearrangements of actin filaments occur during keratinocyte movement
Figure 18-41
Video
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18.6 A model of the molecular events at the leading edge of a moving cell
Figure 18-42
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18.6 Myosin I and myosin II have important roles in cell migration
Figure 18-43
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18.6 Changes in localization of cytosolic Ca2+ during cell location
Figure 18-45
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Chapter 19
Cell Motility and Shape II: Microtubules and Intermediate Filaments
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19.1 Heterodimeric tubulin subunits compose the wall of a microtubule
Figure 19-1
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19.1 Heterodimeric tubulin subunits compose the wall of a microtubule
Figure 19-2
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19.1 Arrangement of protofilaments in singlet, doublet, and triplet microtubules
Figure 19-3
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19.1 Microtubules form a diverse array of both permanent and transient structures
Figure 19-4
Microtubule networks
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19.1 Microtubules assemble from organizing centers
Figure 19-5
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19.1 The -tubulin ring complex nucleates polymerization of tubulin subunits
Figure 19-8
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19.2 The steps of microtubule assembly
Figure 19-11
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19.2 The ends of growing and shortening microtubules appear different
Figure 19-12
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19.2 Dynamic instability is an intrinsic property of microtubules
Figure 19-13
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19.2 Dynamic instability in vivo
Figure 19-14
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19.2 The GTP cap model has been proposed to explain dynamic instability
Figure 19-15
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19.2 Assembly MAPs co-localize with microtubules in vivo
Figure 19-17
Microtubules MAP4
MAP=Microtubule associated proteins
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19.3 Different proteins are transported at different rates along axons
Figure 19-19
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19.3 Fast axonal transport occurs along microtubules
Figure 19-20
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19.3 Intracellular vesicles and some organelles travel along microtubules
Figure 19-22
ER
Microtubules
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19.3 The structure of the kinesin microtubule motor protein
Figure 19-23
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19.3 Kinesin is a (+) end-directed motor
Figure 19-24
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19.3 Microtubule motors: kinesins and dyneins
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19.3 Dynein-associated MBPs tether cargo to microtubules
Figure 19-25
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19.3 Multiple motor proteins are associated with membrane vesicles
Figure 19-26
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19.4 Cilia and flagella: structure and movement
Figure 19-27
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19.4 All eukaryotic cilia and flagella contain bundles of doublet microtubules
Figure 19-28
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19.4 Axonemes are connected to basal bodies
Figure 19-29
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19.4 Ciliary and flagellar beating are produced by controlled sliding of outer doublet microtubules
Figure 19-30
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19.4 Dynein arms generate the sliding forces in axonemes
Figure 19-31
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19.4 Axonemal dyneins are multiheaded motor proteins
Figure 19-32
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19.5 The stages of mitosis and cytokinesis in an animal cell
Figure 19-34Movimento dos cromossomas
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19.6 Functions and structure of intermediate filaments distinguish them from other cytoskeletal fibers
Figure 19-50
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19.6 All IF proteins have a conserved core domain and are organized similarly into filaments
Figure 19-51
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19.6 A purified neurofilament
Figure 19-52
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19.6 Intermediate filaments are dynamic polymers in the cell
Figure 19-53
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19.6 Various proteins cross-link intermediate filaments and connect them to other cell structures
Figure 19-54
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19.6 Intermediate filaments are anchored in cell junctions
Figure 19-56
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19.6 Desmin and associated proteins stabilize sarcomeres in muscle
Figure 19-57