Biological NanoMotors and Their Associated Motor Proteins

Biological NanoMotors and Their Associated Motor Proteins
L. A. Reuter Winona State University Please Note: Much of the graphic material within this PowerPoint presentation came from the reading assignment of “The World of the Cell, sixth edition”, authored by Becker, Kleinsmith & Hardin and published by Pearson-Benjamin Cummings. Find the links to this PowerPoint on the web: (protected site: enter winona\username & password for authentication)

Outline Definitions General Review of Motor proteins
What is a motor protein General Review of Motor proteins Contraction / Depolymerizarion motors Expansion / Polymerization motors Sliding filament motors Actin Myosin Tubulin Walking motor proteins Dynein Kinesin Focus on Bacterial Flagella Rotating flagella Structure of bacterial flagella Relation of bacterial flagella to pili Relation of bacterial flagella to secretory systems Synthesis of bacterial flagella Discussion Possible uses in nanotechnology Outline

Definitions: Motor: Anything that produces or imparts motion.
Biological Motor A motor that is created through life’s processes and which operates as a part of a living being.

Debatable Biological Motors:
(Motor: Anything that produces or imparts motion.) Hexokinase – an enzyme that moves Na+ – K+ ATPase – a transmembrane pump that moves ions across lipid bilayers Other I: Nano – GroEL GroES Chaperone Nano – Holliday Junction Other II: Micro – Brownian Motion Other III: Pico – Molecular Motion Pico – Facilitated Diffusion of Water (~5 x 109 H2O/sec)

Fundamental Motor Protein Principles:
Proteins change their shape when they bind ligands or other molecules. Change of protein shape may drive displacement of other objects.

Contraction / Depolymerizarion motors:
Collagen – an extracellular structural protein Echinoderm connective tissue shortens Tendons shorten after they are stretched Extracellular matrix contracts when fibroblasts “move” Microtubules – (MT are really nanotubules!) MT shorten during mitotic anaphase

ECM Contraction as Fibroblast Shortens
Chapter: 17 Movie: ECMmovie4.mov Description: Effect of fibroblast movement on the ECM. See how fibroblast movement via its lamellipodium affects the extracellular matrix (ECM) surrounding the cell. These differential interference contrast microscopy images show retraction of the lamellipodium (top) as the cell body shortens and moves forward (upward). Notice the compression of the ECM at the base of the lamellipodium caused by the cell shortening. Copyright 2003 The Company of Biologists Ltd. J Cell Sci. W. Petroll, L. Ma, and J. Jester 116,

Figure 17-1 Different Kinds of Extracellular Matrix
Scanning EM picture of loose connective tissue: Fibroblasts Collagen fibers Elastic Fibers Red Blood Cell GAGs

Loose connective tissue

Dense Regular Connective Tissue

Figure 17-2 The Structure of Collagen
Tension strength of a 1 mm diameter fiber is ~9 kg. 67 nm repeat distance of cross striations Stretch < 5%  breaking Protein is high in amounts of: Glycine Hydroxylysine Hydroxyproline Glycine is in the axis of the triple helix, the only aa small enough to fit there

Figure 17-3 Collagen Assembly
270 to 300 nm long, 1.5 nm diameter After action of procollagen peptidase 67 nm repeat distance, ~270 molecules x-sec

Collagen is formed in a fibroblast groove.

Table 17-2 Types of Collagens, Their Occurrence, and Their Structure
Vertebrates have ~25 different kinds of α-chains, each with its own gene and expressed differently in different tissues  >15 types of collagen molecules. Type I collagen accounts for ~90% of collagen in human body.

Figure 15-3 A Model for Microtubule Assembly In Vitro

Figure 15-2 Microtubule Structure
α,β-Heterodimer:  microtubule has direction

Figure 15-4 The Kinetics of Microtubule Assembly In Vitro
Critical concentration Initiation / nucleation is slower than elongation

Figure 15-5 Polar Assembly of Microtubules In Vitro
Basal body (an MTOC) nucleates assembly of microtubules from both ends Plus end grows faster than minus end Critical concentration for the plus end is lower than that for minus end Treadmilling is possible

Figure 15-6 Treadmilling of Microtubules
Critical concentration of heterodimers = concentration at which rate of polymerization = rate of depolymerization

Figure 15-7 The GTP Cap and Its Role in the Dynamic Instability of Microtubules
GTP and Mg++ are required for polymerization Each heterodimer binds two GTP Hydrolysis of GTP is not needed for assembly Interactions between GDP heterodimers is too weak to allow polymerization GTP hydrolysis to GDP gives rise to dynamic instability

Figure 15-8 The Dynamic Instability of Microtubules In Vivo
Chapter: 15 Movie: clspimt.mov Description: Interphase microtubule dynamics. Visualize the dynamic instability of microtubules in a living cell. These images of the lamella of a migrating newt epithelial cell were taken using fluorescence microscopy and rhodamine-labelled tubulin. Notice the alternate lengthening and shortening of individual microtubules as the lamella of the migrating cell moves forward. Courtesy of Edward Salmon. 28 minutes 63μ x 63μ

Figure 15-7 The GTP Cap and Its Role in the Dynamic Instability of Microtubules
Plus and minus ends grow and shrink independently Microtubule Catastrophe = switch from growth phase to shrinkage phase Microtubule Rescue = switch from shrinkage phase to growth phase

Animal Mitosis Chapter: 19 Movie: 12-05-AnimalMitosisVideo-S.mov
Description: Mitosis. Follow the process of mitosis in living animal cells. This dividing cell was imaged using differential interference contrast microscopy. Notice how the chromosomes condense and become visible in prophase, line up at the cell equator in metaphase, and separate into two equal sets in anaphase, just before nuclear membrane reformation at telophase and cell division via cytokinesis.

Mitotic Spindle Formation
Chapter: 19 Movie: fig4.mov Description: Spindle formation during mitosis. Watch how microtubules assemble to form the spindle fibers during prophase of mitosis. These time-lapse images of cells expressing a green fluorescent protein-tubulin fusion were taken using confocal microscopy. Notice how the centrosomes at the opposite ends of the cell act as nucleation sites for the growing microtubules. Courtesy of Ronald Vale.

Anaphase Chapter: 19 Movie: fig4a.anaphase_mitosis.avi
Description: Microtubules in anaphase. Watch how microtubules function during anaphase of mitosis in living cells. These Drosophila S2 cultured cells are expressing a green fluorescent protein-tubulin fusion. Notice the dynamic movement of the microtubules as the spindle poles move apart. Courtesy of Ronald Vale.

Microtubules during Anaphase
Chapter: 4 Movie: DeAna1-medium.mov Description: Microtubules in anaphase See a dividing sand dollar embryo stained to visualize microtubules during its first cleavage. Images are a series of confocal sections spaced 0.5 microns apart through a fixed embryo. Notice how the microtubules radiate from the microtubule-organizing centers. Courtesy of George von Dassow.

Figure 19-1 The Eukaryotic Cell Cycle

Figure 19-20 The Phases of Mitosis in an Animal Cell

Figure 19-22 Attachment of Chromosomes to the Mitotic Spindle

Figure 19-24 The Two Types of Movement Involved in Chromosome Separation During Anaphase
Kinetochore microtubules shorten Axial microtubules lengthen

Figure 19-44 The Use of Laser Photobleaching to Study Chromosome Movement During Mitosis

Na+-K+ ATPase Chapter: 8 Movie: pump-cycle-medium.mov
Description: Na+/K+ ATPase cycle. Watch an amazing video showing how the Na+/K+ ATPase undergoes specific conformational changes as it pumps Na+ out of the cell and K+ into the cell. The cytoplasmic side of the cell is shown at the top of the video. Notice how three Na+ ions are pumped out of the cell for every two K+ ions pumped in. Courtesy of Mark Hilge and Stephan Hilge. Hilge, M.*, Siegal, G., Vuister, G.W., Güntert, P., Gloor, S.M. & Abrahams, J.P. (2003) ATP-induced conformational changes of the nucleotide-binding domain of Na,K-ATPase. Nature Structural Biology, 10,

Brownian Motion

DNA Homologous Recombination
Chapter: 20 Movie: ruvb.mov Description: Model of a Holliday junction. See a proposed model of how the proteins RuvA and RuvB interact with DNA in homologous recombination. RuvA (grey) binds behind the Holliday junction and targets RuvB (white) to opposite sides of one DNA duplex. Notice how single strands of DNA (colors) are exchanged between the two DNA duplexes. Courtesy of David Rice, Peter Artymiuk & John Rafferty, University of Sheffield, UK.

Aquaporin Chapter: 8 Movie: waterpermeation.mpg
Description: Water movement through an aquaporin. See an animation showing how aquaporins act as membrane water channels to regulate the water content of cells. These tetrameric proteins contain very narrow polar openings that allow water to pass through, but block the passage of ions and charged molecules. Notice how the water molecules pass through the aquaporin in single file. Courtesy of Emad Tajkhorshid, Theoretical and Computational Biophysics Group, University of Illinois. E. Tajkhorshid, et al., Science Apr 2002, 296:525.

GroEL ATPase Cycle Movie: groEL_big.mov
Description: GroEL ATPase cycle. View the movement of the protein domains of the molecular chaperone GroEL as it binds nucleotides and GroES. These images of GroEL, a 14-mer composed of two rings of heptamers, were created using cryo EM 3D reconstructions. Notice the four stages in the cycle: a) GroEL; b) GroEL-ADP; c) GroEL-ATP; (7 ATP) d) GroEL-GroES-ATP (GroES= a co-factor) Courtesy of Helen Saibil. Roseman et al (1996) Cell 87, Assisted Self-assembly: Molecular chaperone GroEL assists protein folding in vivo by an ATP-dependent mechanism

Cytokinesis Chapter: 19 Movie: cleavmov.qt
Description: Cleavage of a fertilized egg. Watch as a fertilized frog egg undergoes multiple rounds of mitosis and cytokinesis. Each round of cell division parcels the original cytoplasm into smaller and smaller cells. Notice how the cell divisions appear to be synchronized. Courtesy of Dr Huw Williams and Professor Jim Smith.

Actin-Myosin in Cytokinesis
Chapter: 19 Movie: myosin_cyto.mov Description: Myosin and cytokinesis. See how nonmuscle myosin functions in cytokinesis. These HeLa cultured cells were photographed during cytokinesis using differential interference contrast microscopy. Notice how myosin interacts with a tightening ring of microfilaments called the contractile ring to drive the closure of the ring and divide the cytoplasm between the two daughter cells. Courtesy of Aaron Straight.

Actin-Myosin in Phagocytosis
Chapter: 12 Movie: dictyo.mov Description: Phagocytosis in action. Watch as one cell is consumed by another cell in the process known as phagocytosis. In this video, a yeast cell (red) is being consumed by a larger cell of Dictyostelium, which is expressing a fusion of green fluorescent protein with coronin, an actin-associated protein involved in phagocytosis. Notice the expression of the coronin protein fusion where the Dictyostelium cytoplasm is surrounding the yeast cell. Courtesy of Guenther Gerisch Max-Planck-Institut für Biochemie.

Chemotaxis Demonstration
Chapter: 16 Movie: ax3single.mov Description: Demonstration of chemotaxis. See how a single-celled amoeba moves in response to a chemical attractant. This Dictyostelium cell is showing positive chemotaxis as it moves toward a micropipette tip containing cAMP. Notice how the cell extends a pseudopod to change direction toward the cAMP in response to the movement of the pipette. Courtesy of Susan Lee and Rick Firtel, Section of Cell and Developmental Biology, University of California, San Diego.

Chemotaxis of a Neutrophil
Movie: polariz2.mov Description: Chemotaxis of a neutrophil. Watch a neutrophil move toward a chemical attractant supplied in a glass micropipette. Neutrophils are white blood cells involved in defense against pathogens that respond to chemical signals via G-protein-linked receptors. They are attracted to sites of injured tissue where pathogens may be found. Notice how the cell forms an actin-based protrusion in the direction of the chemoattractant. Courtesy of Henry Bourne.

Lamellipodia in Cell Migration
Chapter: 16 Movie: fishlamellipodia.mov Description: Lamellipodia in cell migration. Watch how a cell is able to move using projections known as lamellipodia. These images of a migrating fish epidermal cell were taken using differential interference contrast microscopy. Notice how the lamellipodium forms a thin sheet at the forward edge of the cell, attaches to the substrate, and then pulls the cell forward. Courtesy of Mark S. Cooper.

Figure 16-25 The Steps of Cell Crawling

Figure 15-15 The Architecture of Actin in Crawling Cells

CAMs – Cytoskeleton - Movement
Chapter: 16 Movie: MOT15S.MOV Description: Regulation of axon movement. See how cell adhesion molecules (CAMs) are important in guiding the movement of neuronal axons. This animation shows how these CAMs interact with the cytoskeleton in response to contact with other cells or surfaces. Notice how small membrane vesicles containing the adhesion molecules are transported to the leading edge of the cell to aid in translocation of the cell. Courtesy of GENERALASAHI Co.,Ltd. GA Digital Graphics and Hiroyuki Kamiguchi, Laboratory for Neuronal Growth Mechanisms, RIKEN Brain Science Institute.

Figure 15-13 A Model for Microfilament Assembly In Vitro
F-actin (filamentous) Directional G-actin (globular)

Figure 15-19 Interrelationships Between the Main Structural Form of Actin

Figure 15-20 Microvillus Structure

Figure 15-21 The Terminal Web of an Intestinal Epithelial Cell

Figure 15-16 Deep-Etch Electron Micrograph Showing Actin Bundles in Filopodia

F-Actin Knot Tying Chapter: ApH Movie: TieFA.mov
Description: Tying a molecular knot. Watch a remarkable video showing how a then undergraduate student Yasuharu Arai used "optical tweezers" to tie a knot in an F-actin microfilament. To do this, polystyrene beads are attached to each end of the microfilament and then held in an optical trap produced by a laser beam. Notice how one end of the microfilament is held motionless, while the other is manipulated to form the molecular knot. From Courtesy of K. Kinosita, Jr. Arai, Y. et al., Nature 399, (1999).

Figure 15A-1 Infection of a Macrophage by Listeria monocytogenes
Listeria can move by polymerizing host actin

Listeria Polymerize Host Cytoplasmic Actin for Movement Listeria monocytogenes: take two
Motility Curiously, although Listeria are actively motile by means of peritrichous flagella at room temperature (20-25 degrees), the organisms do not synthesize flagella at body temperatures (37 degrees). Instead, virulence is associated with another type of motility: the ability of the bacteria to move themselves into, within and between host cells by polymerization of host cell actin at one end of the bacterium ("growing actin tails") that can propel the bacteria through cytoplasm. However, one should not totally dismiss the advantage of flagellar motility for existence and spread of the bacteria outside of the immediate host environment As in the case of Vibrio cholerae, wherein movement, attachment and penetration of the intestinal mucosa are determinants of infection (if not disease), this was thought to be the situation with Listeria, which is also acquired by ingestion and must also find a way to attach to the intestinal mucosa. With cholera, the actively-motile vibrios are thought to use their flagella to swim against the peristaltic movement of the bowel content and to penetrate (by swimming laterally) the mucosal lining of the gut where they adhere.

Figure 16-9 Myosin Family Members

Figure 15-14 Using Myosin S1 Subfragments to Determine Actin Polarity
36 nm repeat

Figure 16-10 Levels of Organization of Skeletal Muscle Tissue

Figure 16-11 Arrangement of Thick and Thin Filaments in a Myofibril

Figure 16-12 Appearance of and Nomenclature for Skeletal Muscle

Figure 16-13 The Thick Filament of Skeletal Muscle

Figure 16-14 The Thin Filament of Striated Muscle

Figure 16-15 Structural Proteins of the Sarcomere

Table 16-2 Major Protein Compounds of Vertebrate Skeletal Muscle

Figure 16-16 The Sliding-Filament Model of Muscle Contraction

Figure 16-17 Cross-Bridges

Figure 16-20 The Sacroplasmic Reticulum and the Transverse Tubule System of Skeletal Muscle Cells

Figure 16-21 Stimulation of a Muscle Cell by a Nerve Impulse

Figure 16-19 Regulation of Contraction in Striated Muscle

Figure 16-18 The Cyclic Process of Muscle Contraction

Figure 16-22 Cardiac Muscle Cells

Cardiac Muscle Contraction
Chapter: 16 Movie: cardio_movie2.mov Description: Calcium-stimulated muscle contraction. Watch the contraction of a heart muscle cell in response to pulses of calcium. This chick embryonic cardiomyocyte is expressing a fusion of green fluorescent protein and myosin. Notice how the repeated contraction of the muscle cell can be monitored by observing the spacing of adjacent Z lines. Copyright 2003 The Company of Biologists Ltd. J Cell Sci Wang et al. 116 (20): 4227.

Figure 16-23 Smooth Muscle and Its Contraction

Figure 16-24 Phosphorylation of Smooth Muscle and Nonmuscle Myosin

Myosin Light Chain Kinase

Actin Moves Along Fixed Myosin
Chapter: 16 Movie: cell_motility1.mov Description: Motility in a cell-free system. See how actin and myosin interact to generate movement, even when isolated from the cell. In this assay, fluorescently-labeled actin filaments were added to a microscope slide coated with purified myosin. Notice how, following the addition of ATP at the beginning of the video, the purified actin filaments are able to move along the immobilized myosin molecules. Courtesy of James Spudich.

Myosin-Actin Interaction
Chapter: 16 Movie: ActScal2.mov Description: Myosin-actin interaction. See the conformational changes of myosin interacting with an actin microfilament. This animation shows an atomic model of the globular head of myosin II while it is docked onto a binding site on the microfilament. Notice the two different conformations the myosin molecule can assume, representing the start and the end of the power stroke. Courtesy of John Trinick, Molecular Contractility Group, Leeds University.

Figure 19-27 Mitotic Motors

Isolated Flagellum Beating
Chapter: 16 Movie: 18µMflagellumbeats.mov Description: Motion of isolated flagellum. See how a flagellum beats in the presence of ATP even when separated from the cell. The flagellum of one of these bull sperm cells was cut in half using a glass microprobe. Notice how the excised piece of the flagellum continues to beat in the absence of any connection to the original cell. Dana L. Holcomb-Wygle, Kathleen A. Lesich, and Charles B. Lindemann. Oakland University, Department of Biological Sciences, Rochester, Michigan 48309

Mouse Sperm Secondary Waves
Chapter: 16 Movie: SecondaryW.mov Description: Flagellum movement in swimming sperm. See the complex motion of the flagellum of an immobilized mouse sperm. These images were taken using dark-field microscopy, with the recorded image inverted to show the cell as dark against a light background. As the flagellum undulates, notice the presence of smaller secondary waves superimposed upon the large back-and-forth primary waves. Courtesy of Geraint Vernon.

Figure 16-6 Cilia and Flagella

Coordinated Ciliary Motion
Chapter: 16 Movie: metachrony.mpg Description: Ciliary motion. See the movement of cilia on living cells. Cilia are short hair-like projections used for locomotion or for feeding in protozoa, or for clearing of particles from respiratory airways in animals. They are similar to flagella but much more numerous, often completely covering a cell. Notice the coordinated beating of waves of cilia on the cell in this video. Courtesy of Michael Sanderson.

Figure 16-6 Cilia and Flagella

Figure 16-7 The Structure of Cilium

Figure 16-8 Enlarged Views of an Axoneme

Flagellum Sliding Filament
Chapter: 16 Movie: B14frames.mov Description: Microtubule sliding in flagellum movement. Observe the sliding of microtubule doublets that is responsible for the movement of a sperm cell flagellum. Tiny gold beads (40 nm diameter) were attached to opposite sides of this flagellum and ATP was added to stimulate movement. Notice how the beads move relative to each other, demonstrating the microtubule sliding action that causes the flagellum to bend. Animation courtesy of Charles J. Brokaw, California Institute of Technology. Details of this type of experiment were published in Brokaw, C. J., J. Cell Biol. 114: (1991).

Organelles Move Along Microtubules
Chapter: 16 Movie: otmovie.mov Description: Movement of organelles in vivo. Watch as organelles are transported along microtubules in an axon of a neuron. This cell of Aplysia, a marine snail used in neurobiology research, was photographed using high-resolution differential interference contrast microscopy. Notice how organelles are moving in opposite directions on different microtubule tracks. Courtesy of Paul Forscher, Department of Molecular, Cellular, and Developmental Biology, Yale University.

Elodea Cyclosis Chapter: 11 Movie: Elodea_Cyclosis.mov
Description: Chloroplast movement. Watch the movement of chloroplasts in a live aquatic plant cell. This video shows cells of Elodea, a fresh-water plant commonly used in home aquariums. Notice how many chloroplasts are present in each cell and how they move around the cell, enabling the plant to take advantage of differing light conditions.

ER to Golgi Vesicle Movement
Chapter: 12 Movie: uobf1.mov Description: ER to Golgi traffic. Watch glycoprotein movement through the secretory pathway of living cells. Green fluorescent protein was fused to a protein destined for secretion in order to visualize its movement from the ER into the Golgi complex at the center of this cell. Notice how the protein fusion moves in a stop-and-go fashion into the Golgi, where it undergoes final processing prior to secretion. Courtesy of Jennifer Lippincott-Schwartz.

GFP-KDEL Chapter: 4, 12 Movie: ER2.avi
Description: Protein targeting to the endoplasmic reticulum using GFP-KDEL. Visualize ER-localized gene expression in a tobacco leaf epidermal cell. A protein fusion of green fluorescent protein, an ER signal sequence, and the four-amino-acid KDEL ER retention sequence is targeted and expressed in the ER lumen. Courtesy of Chris Hawes and Petra Boevink.

Moving ER Vesicles Chapter: 4 Movie: ichida2.mov
Description: ER and Mitochondria in leaf cells See images from living tobacco leaf cells showing the movement of the ER (green) and mitochondria (red). Video frames were taken every 2 seconds over a period of 3 minutes, 22 seconds. Notice how dynamic the cell cytoplasm is in these live cells. Courtesy of Barbara Pickard and Audrey Ichida.

Melanin Transport Along Microtubules
Chapter: 16 Movie: MT_melanophor.mov Description: Transport along microtubules. Watch the movement of granules containing the dark pigment melanin as they travel along microtubules in a fish epidermal cell. This movement of melanin granules enables the fish to change its color to avoid predators. Rhodamine-labeled tubulin was used to visualize the microtubules. Notice how some of the microtubules appear to move as tubulin monomers are added to one end and removed from the other. Courtesy of Gary G. Borisy.

Movement of Organelles
Chapter: 16 Movie: DissAxo.mov Description: Movement of organelles in vitro. Watch as organelles are transported along microtubules isolated from the giant axon of a squid cell. These images were made using video-enhanced differential interference contrast microscopy. Notice how, once ATP is added, organelle movement is observed even when the microtubules are outside the cell cytoplasm. Courtesy of Ronald Vale.

Table 16-1 Selected Motor Proteins of Eukaryotic Cells

Figure 16-1 Deep-Etch Electron Micrograph Showing a Vesicle Attached to a Microtubule in a Crayfish Axon

Figure 16-2 Microtubule-Based Motility

Figure 16-3 Movement of Kinesin

Figure 16-4 Schematic Representation of the Cytoplasmic Dynein/Dynactin Complex

Figure 16-5 Microtubules, Motor MAPs, and the Golgi Complex: A Model

Figure The Flow of Electrons Through Respiratory Complexes I, III, and IV with Concomitant Directional Proton Pumping 11P 43P 13P

Figure 10-18 F1 and F0 Components of the Bacterial F0F1ATP Synthase

ATP Synthetase (Top View) ATP Synthetase (Side View)
Chapter: 10 Movie: F1_top_sp_2.mov Description: ATP synthase 3D structure. Watch a top view of the conformational changes in the ATPase F1 complex during one 360° rotation of the stalk. The three  subunits are shown in yellow, the three  subunits in red+green, and the stalk in blue+grey. Notice how each rotation consists of three successive 120° movements of the stalk, causing large domain shifts in the  and  subunits. Courtesy of George Oster and Hongyun Wang.

Figure 20-20 The Cellular Apparatus for Bacterial Conjugation

10-16 watts proton motive force
Salmonella 1974 rotary motor 10 x 10,000 nm 20,000 rpm 10-16 watts proton motive force 80% efficiency ~30 flagellar proteins, several to 10s of K

The End (for this evening)

Gliding Gliding motion in Bacteria

Figure 20-20 The Cellular Apparatus for Bacterial Conjugation

Figure 20-21 DNA Transfer by Bacterial Conjugation

Chromatium A motile, purple, sulphur bacterium.

Rhodospirillum rubrum
A motile, purple, non-sulphur, bacterium.

Neuron Growth Cone Actin and Tubulin
Chapter: 4, 15, A Movie: movinggceffect.mov Description: The cytoskeleton in a neuron growth cone. See the localization of actin and tubulin in a neuron growth cone of Aplysia, a marine snail used in neural development research. The video shows a differential interference contrast (DIC) image, followed by images of staining for F-actin (red) and tubulin (green). Notice the highly organized structure of different regions of the cell cytoskeleton. Courtesy of Paul Forscher.

Actin in Lamellipodium
Chapter: 15 Movie: kerat.mov Description: Actin network in crawling cells. See the actin microfilament network in the lamellipodium of a Xenopus keratocyte that was cultured on a glass coverslip. The video shows the cell in motion, followed by electron microscopy to visualize the extensive actin network present in the lamellipodium. Notice the extensive branching of the actin network (highlighted in yellow). Courtesy of Gary Borisy.

GFP Marker in Mice Chapter: 20 Movie: okabe1.mov
Description: GFP-expressing transgenic mice. See transgenic mice produced by introducing the gene encoding green fluorescent protein (GFP) under the control of an actin promoter. These mice express GFP in all tissues where actin is normally expressed and glow green when exposed to blue or UV light, making them useful for studies of cell fate in cell transplantation experiments. Notice how not all pups in this litter are expressing the transgene. Courtesy of Masaru Okabe.

Pronuclear Injection Chapter: 20 Movie: PNI.mov
Description: Pronuclear injection. Watch an early step in the production of transgenic mice. In this video, a microscopic glass needle containing DNA is inserted into the pronucleus of a fertilized mouse oocyte that is held in place by suction against a micropipette at the left edge of the video. Following integration of the introduced DNA into the host cell chromosome, the transgenic embryonic cell will be implanted into a female foster mouse. Courtesy of Ronald Naumann.

G Protein Heterotrimer
Chapter: 14 Movie: Heterotrimer_G_Prote#1DB7D9.avi Description: Heterotrimeric G protein structure. See the conformational changes induced in a heterotrimeric G protein following GTP binding and hydrolysis. The GTPase domain of the G subunit is shown in green. Notice how the G subunit dissociates from the G and the G subunits following GTP binding. Provided by Cameron Slayden.

Ca++-ATPase Chapter: 8 Movie: Ca-ATPase-surface-motion.mpg
Description: Ca-ATPase cycle. Watch the conformational changes induced in the membrane-bound Ca-ATPase during one cycle of calcium binding, phosphorylation, and calcium release. Binding of calcium ions causes a conformational change, exposing a phosphorylation site. Phosphorylation by ATP causes a further conformational change resulting in calcium release on the other side of the membrane. Courtesy of Mark B. Gerstein.

Mitosis and Nondisjunction
Chapter: 19 Movie: nondisjun.mov Description: Nondisjunction in mitosis. See what happens when mitosis malfunctions. Newt epithelial cells were grown on cover slips and photographed using differential interference contrast microscopy. Notice how, in this cell, one chromosome (black arrow) never arrives at the equatorial plate, likely due to improper attachment to the spindle fiber. As in meiotic nondisjunction, this will result in the daughter cells having abnormal numbers of chromosomes. Time-lapse sequence by Dr. Conly L. Rieder, Wadsworth Center, Albany, New York

Figure 15-17 Branched Actin Networks and the Arp2/3 Complex

Figure The Stimulation of G Protein-Linked Signal Transduction Pathways by - and -Adrenergic Receptors

Figure 14-24 Stimulation of Glycogen Breakdown by Epinephrine

Figure 14-18 Signal Transduction Through Receptor Tyrosine Kinases

Table 14-2 Examples of Growth Factor Families

Figure 15-1 The Intracellular Distribution of Microtubules, Microfilaments, and Intermediate Filaments

Table 15-1 Properties of Microtubules, Microfilaments, and Intermediate Filaments

Table 15-2 Techniques for Studying the Cytoskeleton
Drugs: Colchicine; nocodazol; taxol; cytochalasin D, B; lantrunculin; phalloidin (inhibit polymerization / inhibit depolymerization)

Figure 15-9 The Centrosome

Figure 15-10 -Tubulin at the Base of Microtubules Originating from the Centrosome

Figure 15-11 The Effects of Microtubule Polarity on MT Orientation in Animal Cells

Figure 15-18 Regulation of Protrusions by Small G Proteins

Figure 15-22 Support of the Erythrocyte Plasma Membrane by a Spectrin-Ankyrin-Actin Network

Figure 15-23 Intermediate Filaments

Table 15-3 Classes of Intermediate Filaments

Figure 15-24 Structural Similarities of Intermediate Filament Proteins

Figure 15-25 A Model for Intermediate Filament Assembly In Vitro

Figure 15-26 Connections Between Intermediate Filaments and Other Components of the Cytoskeleton

Figure 16A-1 Scanning Electron Micrograph of Epithelial Cells of the Inner Ear Showing Several Rows of Stereocilia

Figure Scanning Electron Micrograph of a Mouse Fibroblast Showing Numerous Filopodia Extending from the Cell Surface

Figure 16-27 Attachment Coupled to Protrusion Formation in a Migrating Cell

Figure 16-28 Overall Distribution of Myosin II and Actin in a Fibroblast

Figure 16-29 Amoeboid Movement

Figure 17A-1 Bacterial Pathogens and Cell Adhesion Proteins

Figure 17-1 Different Kinds of Extracellular Matrix

Table 17-1 Extracellular Structures of Eukaryotic Cells

Figure 17-4 Stretching and Recoiling of Elastin Fibers

Figure 22-16 A Model for the Signal Mechanism of Cotranslational Import

Figure 22-17 Cotranslational Insertion of Transmembrane Proteins into the ER Membrane

Figure Main Polypeptide Transport Complexes of the Outer and Inner Membranes of Mitochondria and Chloroplasts

Figure Experimental Demonstration That Polypeptides Span Both Mitochondrial Membranes During Import

Figure 22-20 Posttranslational Import of Polypeptides into the Mitochondrion

Figure 22-21 The Structure of Puromycin

Figure 22-2 Important Binding Sites of the Prokaryotic Ribosome

Figure 21-11 A Closeup of the Prokaryotic Elongation Complex

Figure Termination of Transcription in Prokaryotic Genes That Do Not Require the Rho Termination Factor

Figure 19-28 Cytokinesis in an Animal Cell

Figure 19-29 Cytokinesis and Cell Plate Formation in a Plant Cell

Figure 19-30 Cleavage of a Fertilized Egg into Progressively Smaller Cells

Figure 19-41 Growth Factor Signaling via the Ras Pathway

Figure 19-42 The PI3K-Akt Signaling Pathway

Figure 19-25 Microtubule Polarity in the Mitotic Spindle

Figure 19-21 The Phases of Mitosis in a Plant Cell

Figure 19-26 Kinetochores and Their Microtubules

Biological NanoMotors and Their Associated Motor Proteins

Similar presentations

Presentation on theme: "Biological NanoMotors and Their Associated Motor Proteins"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Biological NanoMotors and Their Associated Motor Proteins

Similar presentations

Presentation on theme: "Biological NanoMotors and Their Associated Motor Proteins"— Presentation transcript:

Similar presentations

About project

Feedback