![Page 1: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/1.jpg)
CytoskeletonMade of proteinsDynamic propertiesCoordinate with each other Coordinate with external signal
![Page 2: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/2.jpg)
Biological functions of the cytoskeleton
Tissue level Cell levelMuscle movement Cell shape
Cell movementCell adhesionMitosis
Subcellular levelIntracellular movement of vesiclesLocation of subcellular organellesOrganizing cell polarityEndocytosis – clathrin-mediated endocytosis and
phagocytosis
![Page 3: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/3.jpg)
Actin cytoskeleton
G-actin F-actinMg++
-
+
![Page 4: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/4.jpg)
Microtubule
Taxol
ExchangeableNon exchangeable
+ -
![Page 5: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/5.jpg)
Polymerization of G-actin
![Page 6: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/6.jpg)
0.6 μM 0.1 μM
Cc – Critical concentration
Treadmilling of actin filaments
![Page 7: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/7.jpg)
Assembly of microtubules
![Page 8: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/8.jpg)
Dynamic instability of microtubules
![Page 9: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/9.jpg)
Organization of the actin cytoskeleton
![Page 10: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/10.jpg)
Protein involved in the actin cytoskeleton
organization
![Page 11: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/11.jpg)
Regulation of actin
polymerization
![Page 12: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/12.jpg)
Figure 3. Dendritic Nucleation/Array Treadmilling Model for Protrusion of the Leading Edge(1) Extracellular signals activate receptors. (2) The associated signal transduction pathways produce active Rho-family GTPases and PIP2 that (3) activate WASp/Scar proteins. (4) WASp/Scar proteins bring together Arp2/3 complex and an actin monomer on the side of a preexisting filament to form a branch. (5) Rapid growth at the barbed end of the new branch (6) pushes the membrane forward. (7) Capping protein terminates growth within a second or two. (8) Filaments age by hydrolysis of ATP bound to each actin subunit (white subunits turn yellow) followed by dissociation of the γ phosphate (subunits turn red). (9) ADF/cofilin promotes phosphate dissociation, severs ADP-actinfilaments and promotes dissociation of ADP-actin from filament ends. (10)Profilin catalyzes the exchange of ADP for ATP (turning the subunits white), returning subunits to (11) the pool of ATP-actin bound to profilin, ready to elongate barbed ends as they become available. (12) Rho-family GTPases also activate PAK and LIM kinase, which phosphorylates ADF/cofilin. This tends to slow down the turnover of the filaments. (Redrawn from a figure in Pollard et al., 2000). Reprinted with permission from the Annual Review of Biophysics and Biomolecular Structure, Volume 29, copyright 2000 by Annual Reviews, www.annualreviews.org.
![Page 13: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/13.jpg)
Centrosome - a microtubule-organization center
C, centrioles; PC, pericentriolar matrix,
![Page 14: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/14.jpg)
Orientation of cellular microtubules
![Page 15: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/15.jpg)
γ-tubulin ring complex
The γ-tubulin ring complex is localized to one end of the microtubule
![Page 16: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/16.jpg)
Motors of the actin filaments
![Page 17: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/17.jpg)
Functions of myosin tail domains
![Page 18: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/18.jpg)
Kinesins (+) end-directed microtubule motors
![Page 19: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/19.jpg)
Kinesin-catalyzed vesicle transport
![Page 20: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/20.jpg)
Dynein (-) end-directed microtubule motors
![Page 21: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/21.jpg)
Actin-mediated cell migration
![Page 22: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/22.jpg)
Actin-mediated movement of Listeria in infected fibroblasts
![Page 23: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/23.jpg)
![Page 24: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/24.jpg)
ER
microtubules
![Page 25: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/25.jpg)
Sperm Chlamydomonas
Flagella-mediated movement
![Page 26: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/26.jpg)
![Page 27: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/27.jpg)
Cooperation of myosin and kinesin at cell cortex
![Page 28: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/28.jpg)
![Page 29: Cytoskeleton - science.umd.eduscience.umd.edu/cbmg/faculty/song/688D/Lectures/Cytoskeleton.pdf · Biological functions of the cytoskeleton Tissue level Cell level Muscle movement](https://reader030.vdocuments.mx/reader030/viewer/2022040417/5d4edc2488c99350518b9b22/html5/thumbnails/29.jpg)