51
|
Abstract
The centrosome, a major organizer of microtubules, has important functions in regulating cell shape, polarity, cilia formation and intracellular transport as well as the position of cellular structures, including the mitotic spindle. By means of these activities, centrosomes have important roles during animal development by regulating polarized cell behaviors, such as cell migration or neurite outgrowth, as well as mitotic spindle orientation. In recent years, the pace of discovery regarding the structure and composition of centrosomes has continuously accelerated. At the same time, functional studies have revealed the importance of centrosomes in controlling both morphogenesis and cell fate decision during tissue and organ development. Here, we review examples of centrosome and centriole positioning with a particular emphasis on vertebrate developmental systems, and discuss the roles of centrosome positioning, the cues that determine positioning and the mechanisms by which centrosomes respond to these cues. The studies reviewed here suggest that centrosome functions extend to the development of tissues and organs in vertebrates.
Collapse
Affiliation(s)
- Nan Tang
- Department of Anatomy, Cardiovascular Research Institute, The University of California, San Francisco, USA.
| | | |
Collapse
|
52
|
Maninová M, Klímová Z, Parsons JT, Weber MJ, Iwanicki MP, Vomastek T. The reorientation of cell nucleus promotes the establishment of front-rear polarity in migrating fibroblasts. J Mol Biol 2013; 425:2039-2055. [PMID: 23524135 DOI: 10.1016/j.jmb.2013.02.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 02/10/2013] [Accepted: 02/19/2013] [Indexed: 11/27/2022]
Abstract
The establishment of cell polarity is an essential step in the process of cell migration. This process requires precise spatiotemporal coordination of signaling pathways that in most cells create the typical asymmetrical profile of a polarized cell with nucleus located at the cell rear and the microtubule organizing center (MTOC) positioned between the nucleus and the leading edge. During cell polarization, nucleus rearward positioning promotes correct microtubule organizing center localization and thus the establishment of front-rear polarity and directional migration. We found that cell polarization and directional migration require also the reorientation of the nucleus. Nuclear reorientation is manifested as temporally restricted nuclear rotation that aligns the nuclear axis with the axis of cell migration. We also found that nuclear reorientation requires physical connection between the nucleus and cytoskeleton mediated by the LINC (linker of nucleoskeleton and cytoskeleton) complex. Nuclear reorientation is controlled by coordinated activity of lysophosphatidic acid (LPA)-mediated activation of GTPase Rho and the activation of integrin, FAK (focal adhesion kinase), Src, and p190RhoGAP signaling pathway. Integrin signaling is spatially induced at the leading edge as FAK and p190RhoGAP are predominantly activated or localized at this location. We suggest that integrin activation within lamellipodia defines cell front, and subsequent FAK, Src, and p190RhoGAP signaling represents the polarity signal that induces reorientation of the nucleus and thus promotes the establishment of front-rear polarity.
Collapse
Affiliation(s)
- Miloslava Maninová
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Zuzana Klímová
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | - Michael J Weber
- University of Virginia Health System, Charlottesville, VA, USA
| | | | - Tomáš Vomastek
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| |
Collapse
|
53
|
Kim N, Song K. KIFC1 is essential for bipolar spindle formation and genomic stability in the primary human fibroblast IMR-90 cell. Cell Struct Funct 2013; 38:21-30. [PMID: 23318213 DOI: 10.1247/csf.12014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Kinesin family member C1 (KIFC1) is the only member of the minus-end-directed kinesin-14 family in human cells. In cancer cells, KIFC1 plays an essential role in bipolar spindle formation by clustering the multiple poles during mitosis. However, it has not been clearly demonstrated whether KIFC1 also functions to mediate bipolar spindle formation and to maintain genomic stability in normal cells. In this study, by using human primary lung fibroblast IMR-90 cells, we showed that KIFC1 knock-down with lentiviral KIFC1 shRNA induced 17% of cells with multiple microtubule organizing centers (MTOCs) and delayed cyclin A degradation for more than 2 hr in early mitosis. However, these cells eventually carried out mitosis, resulting in 24% of cells with lagging chromosomes and 9% of cells with micronuclei after mitosis. Karyotyping of KIFC1-depleted IMR-90 cells demonstrated that cells with various abnormal numbers of chromosomes are produced. When IMR-90 cells treated with KIFC1 or the control shRNA for 60 hr were compared, 20% less cells were observed in KIFC1-depleted cells without an obvious immediate cell death. As reported for Mad2 depletion in IMR-90 cells, KIFC1-depleted IMR-90 cells showed typical features of senescence, like senescence-associated (SA) β-galactosidase expression, when incubated 6 days or more. However, IMR-90 cells knocked down with both KIFC1 and Mad2 underwent apoptosis, suggesting that KIFC1 and Mad2 likely function in different pathways during mitosis. Taken together, we suggest that KIFC1 plays an essential role for bipolar MTOC formation and maintaining chromosomal stability in the mitosis of human primary fibroblast IMR-90.
Collapse
Affiliation(s)
- Namil Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | | |
Collapse
|
54
|
Burakov AV, Nadezhdina ES. Association of nucleus and centrosome: magnet or velcro? Cell Biol Int 2013; 37:95-104. [DOI: 10.1002/cbin.10016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/12/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Anton V. Burakov
- A.N.Belozersky Institute of Physico-Chemical Biology of Lomonosov Moscow State University; Vorobjevy Gory, 1/40, Moscow 119992 Russia
| | - Elena S. Nadezhdina
- A.N.Belozersky Institute of Physico-Chemical Biology of Lomonosov Moscow State University; Vorobjevy Gory, 1/40, Moscow 119992 Russia
- Institute of Protein Research of Russian Academy of Science; Vavilova ul., 34, Moscow 119333 Russia
| |
Collapse
|
55
|
Marshall WF, Young KD, Swaffer M, Wood E, Nurse P, Kimura A, Frankel J, Wallingford J, Walbot V, Qu X, Roeder AHK. What determines cell size? BMC Biol 2012; 10:101. [PMID: 23241366 PMCID: PMC3522064 DOI: 10.1186/1741-7007-10-101] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 12/12/2012] [Indexed: 11/16/2022] Open
Affiliation(s)
- Wallace F Marshall
- Department of Biochemistry and Biophysics, Center for Systems and Synthetic Biology, University of California, San Francisco, 600 16th St, San Francisco, CA 94158, USA
| | - Kevin D Young
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Matthew Swaffer
- Cell Cycle Lab, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
| | - Elizabeth Wood
- Cell Cycle Lab, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
| | - Paul Nurse
- Cell Cycle Lab, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK
- Laboratory of Yeast Genetics and Biology, The Rockeller University, 1230 York Avenue, New York, NY 10065, USA
- The Francis Crick Institute, Euston Road 215, London, NW1 2BE, UK
| | - Akatsuki Kimura
- Cell Architecture Laboratory, Structural Biology Center, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Joseph Frankel
- Department of Biology, University of Iowa, 129 E. Jefferson Street, Iowa City, IA 52242, USA
| | - John Wallingford
- HHMI & Molecular Cell and Developmental Biology, University of Texas, Austin, 78712, USA
| | - Virginia Walbot
- Virginia WalbotDepartment of Biology, Stanford University, Stanford, CA 72205, USA
| | - Xian Qu
- Xian Qu, Cornell University, 244 Weill Hall, 526 Campus Rd, Ithaca, NY 14853, USA
| | - Adrienne HK Roeder
- Cornell University, 239 Weill Hall, 526 Campus Rd, Ithaca, NY 14853, USA
| |
Collapse
|
56
|
Shekhar N, Wu J, Dickinson RB, Lele TP. Cytoplasmic dynein: tension generation on microtubules and the nucleus. Cell Mol Bioeng 2012; 6:74-81. [PMID: 23646068 DOI: 10.1007/s12195-012-0257-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Cytoplasmic dynein is a microtubule dependent motor protein that is central to vesicle transport, cell division and organelle positioning. Recent studies suggest that dynein can generate significant pulling forces on intracellular structures as it motors along microtubules. In this review, we discuss how dynein-generated pulling forces position the nucleus and the centrosome.
Collapse
Affiliation(s)
- Nandini Shekhar
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611
| | | | | | | |
Collapse
|
57
|
Laan L, Roth S, Dogterom M. End-on microtubule-dynein interactions and pulling-based positioning of microtubule organizing centers. Cell Cycle 2012; 11:3750-7. [PMID: 22895049 PMCID: PMC3495818 DOI: 10.4161/cc.21753] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
During important cellular processes such as centrosome and spindle positioning, dynein at the cortex interacts with dynamic microtubules in an apparent "end-on" fashion. It is well-established that dynein can generate forces by moving laterally along the microtubule lattice, but much less is known about dynein's interaction with dynamic microtubule ends. In this paper, we review recent in vitro experiments that show that dynein, attached to an artificial cortex, is able to capture microtubule ends, regulate microtubule dynamics and mediate the generation of pulling forces on shrinking microtubules. We further review existing ideas on the involvement of dynein-mediated cortical pulling forces in the positioning of microtubule organizing centers such as centrosomes. Recent in vitro experiments have demonstrated that cortical pulling forces in combination with pushing forces can lead to reliable centering of microtubule asters in quasi two-dimensional microfabricated chambers. In these experiments, pushing leads to slipping of microtubule ends along the chamber boundaries, resulting in an anisotropic distribution of cortical microtubule contacts that favors centering, once pulling force generators become engaged. This effect is predicted to be strongly geometry-dependent, and we therefore finally discuss ongoing efforts to repeat these experiments in three-dimensional, spherical and deformable geometries.
Collapse
Affiliation(s)
- Liedewij Laan
- Faculty of Arts and Sciences; Center for Systems Biology; Harvard University; Cambridge, MA USA
| | - Sophie Roth
- FOM Institute AMOLF; Amsterdam, The Netherlands
| | | |
Collapse
|
58
|
Vignaud T, Blanchoin L, Théry M. Directed cytoskeleton self-organization. Trends Cell Biol 2012; 22:671-82. [PMID: 23026031 DOI: 10.1016/j.tcb.2012.08.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 08/30/2012] [Accepted: 08/31/2012] [Indexed: 12/13/2022]
Abstract
The cytoskeleton architecture supports many cellular functions. Cytoskeleton networks form complex intracellular structures that vary during the cell cycle and between different cell types according to their physiological role. These structures do not emerge spontaneously. They result from the interplay between intrinsic self-organization properties and the conditions imposed by spatial boundaries. Along these boundaries, cytoskeleton filaments are anchored, repulsed, aligned, or reoriented. Such local effects can propagate alterations throughout the network and guide cytoskeleton assembly over relatively large distances. The experimental manipulation of spatial boundaries using microfabrication methods has revealed the underlying physical processes directing cytoskeleton self-organization. Here we review, step-by-step, from molecules to tissues, how the rules that govern assembly have been identified. We describe how complementary approaches, all based on controlling geometric conditions, from in vitro reconstruction to in vivo observation, shed new light on these fundamental organizing principles.
Collapse
Affiliation(s)
- Timothée Vignaud
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherche en Technologies et Sciences pour le Vivant, CNRS/UJF/INRA/CEA, 17 Rue des Martyrs, 38054, Grenoble, France
| | | | | |
Collapse
|
59
|
Abstract
The centrosome acts as the main microtubule-nucleating organelle in animal cells and plays a critical role in mitotic spindle orientation and in genome stability. Yet, despite its central role in cell biology, the centrosome is not present in all multicellular organisms or in all cells of a given organism. The main outcome of centrosome reproduction is the transmission of polarity to daughter cells and, in most animal species, the sperm-donated centrosome defines embryo polarity. Here I will discuss the role of the centrosome in cell polarity, resulting from its ability to position the nucleus at the cell center, and discuss how centrosome innovation might have been critical during metazoan evolution.
Collapse
Affiliation(s)
- Michel Bornens
- UMR144 du Centre Nationale de la Recherche Scientifique, Institut Curie, 26 rue d'Ulm, Paris Cedex 05, France.
| |
Collapse
|
60
|
Laan L, Pavin N, Husson J, Romet-Lemonne G, van Duijn M, López MP, Vale RD, Jülicher F, Reck-Peterson SL, Dogterom M. Cortical dynein controls microtubule dynamics to generate pulling forces that position microtubule asters. Cell 2012; 148:502-14. [PMID: 22304918 PMCID: PMC3292199 DOI: 10.1016/j.cell.2012.01.007] [Citation(s) in RCA: 275] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 09/08/2011] [Accepted: 01/03/2012] [Indexed: 10/14/2022]
Abstract
Dynein at the cortex contributes to microtubule-based positioning processes such as spindle positioning during embryonic cell division and centrosome positioning during fibroblast migration. To investigate how cortical dynein interacts with microtubule ends to generate force and how this functional association impacts positioning, we have reconstituted the 'cortical' interaction between dynein and dynamic microtubule ends in an in vitro system using microfabricated barriers. We show that barrier-attached dynein captures microtubule ends, inhibits growth, and triggers microtubule catastrophes, thereby controlling microtubule length. The subsequent interaction with shrinking microtubule ends generates pulling forces up to several pN. By combining experiments in microchambers with a theoretical description of aster mechanics, we show that dynein-mediated pulling forces lead to the reliable centering of microtubule asters in simple confining geometries. Our results demonstrate the intrinsic ability of cortical microtubule-dynein interactions to regulate microtubule dynamics and drive positioning processes in living cells.
Collapse
Affiliation(s)
- Liedewij Laan
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
61
|
Hale CM, Chen WC, Khatau SB, Daniels BR, Lee JSH, Wirtz D. SMRT analysis of MTOC and nuclear positioning reveals the role of EB1 and LIC1 in single-cell polarization. J Cell Sci 2011; 124:4267-85. [PMID: 22193958 DOI: 10.1242/jcs.091231] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In several migratory cells, the microtubule-organizing center (MTOC) is repositioned between the leading edge and nucleus, creating a polarized morphology. Although our understanding of polarization has progressed as a result of various scratch-wound and cell migration studies, variations in culture conditions required for such assays have prevented a unified understanding of the intricacies of MTOC and nucleus positioning that result in cell polarization. Here, we employ a new SMRT (for sparse, monolayer, round, triangular) analysis that uses a universal coordinate system based on cell centroid to examine the pathways regulating MTOC and nuclear positions in cells plated in a variety of conditions. We find that MTOC and nucleus positioning are crucially and independently affected by cell shape and confluence; MTOC off-centering correlates with the polarization of single cells; acto-myosin contractility and microtubule dynamics are required for single-cell polarization; and end binding protein 1 and light intermediate chain 1, but not Par3 and light intermediate chain 2, are required for single-cell polarization and directional cell motility. Using various cellular geometries and conditions, we implement a systematic and reproducible approach to identify regulators of MTOC and nucleus positioning that depend on extracellular guidance cues.
Collapse
Affiliation(s)
- Christopher M Hale
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | | | | | | | | | | |
Collapse
|
62
|
Centrosomes, microtubules and neuronal development. Mol Cell Neurosci 2011; 48:349-58. [DOI: 10.1016/j.mcn.2011.05.004] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 05/12/2011] [Accepted: 05/15/2011] [Indexed: 11/24/2022] Open
|
63
|
Wu J, Misra G, Russell RJ, Ladd AJC, Lele TP, Dickinson RB. Effects of dynein on microtubule mechanics and centrosome positioning. Mol Biol Cell 2011; 22:4834-41. [PMID: 22013075 PMCID: PMC3237626 DOI: 10.1091/mbc.e11-07-0611] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
When microtubules are severed by laser ablation, newly created minus ends increase in curvature, but they straighten when dynein is inhibited. It is found that cytoplasmic dynein generates tension and friction along microtubule lengths and that these forces govern the dynamics of centrosome centering. To determine forces on intracellular microtubules, we measured shape changes of individual microtubules following laser severing in bovine capillary endothelial cells. Surprisingly, regions near newly created minus ends increased in curvature following severing, whereas regions near new microtubule plus ends depolymerized without any observable change in shape. With dynein inhibited, regions near severed minus ends straightened rapidly following severing. These observations suggest that dynein exerts a pulling force on the microtubule that buckles the newly created minus end. Moreover, the lack of any observable straightening suggests that dynein prevents lateral motion of microtubules. To explain these results, we developed a model for intracellular microtubule mechanics that predicts the enhanced buckling at the minus end of a severed microtubule. Our results show that microtubule shapes reflect a dynamic force balance in which dynein motor and friction forces dominate elastic forces arising from bending moments. A centrosomal array of microtubules subjected to dynein pulling forces and resisted by dynein friction is predicted to center on the experimentally observed time scale, with or without the pushing forces derived from microtubule buckling at the cell periphery.
Collapse
Affiliation(s)
- Jun Wu
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | | | | | | | | | | |
Collapse
|
64
|
Shinar T, Mana M, Piano F, Shelley MJ. A model of cytoplasmically driven microtubule-based motion in the single-celled Caenorhabditis elegans embryo. Proc Natl Acad Sci U S A 2011; 108:10508-13. [PMID: 21670261 PMCID: PMC3127902 DOI: 10.1073/pnas.1017369108] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We present a model of cytoplasmically driven microtubule-based pronuclear motion in the single-celled Caenorhabditis elegans embryo. In this model, a centrosome pair at the male pronucleus initiates stochastic microtubule (MT) growth. These MTs encounter motor proteins, distributed throughout the cytoplasm, that attach and exert a pulling force. The consequent MT-length-dependent pulling forces drag the pronucleus through the cytoplasm. On physical grounds, we assume that the motor proteins also exert equal and opposite forces on the surrounding viscous cytoplasm, here modeled as an incompressible Newtonian fluid constrained within an ellipsoidal eggshell. This naturally leads to streaming flows along the MTs. Our computational method is based on an immersed boundary formulation that allows for the simultaneous treatment of fluid flow and the dynamics of structures immersed within. Our simulations demonstrate that the balance of MT pulling forces and viscous nuclear drag is sufficient to move the pronucleus, while simultaneously generating minus-end directed flows along MTs that are similar to the observed movement of yolk granules toward the center of asters. Our simulations show pronuclear migration, and moreover, a robust pronuclear centration and rotation very similar to that observed in vivo. We find also that the confinement provided by the eggshell significantly affects the internal dynamics of the cytoplasm, increasing by an order of magnitude the forces necessary to translocate and center the pronucleus.
Collapse
Affiliation(s)
- Tamar Shinar
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA.
| | | | | | | |
Collapse
|
65
|
Smith E, Hégarat N, Vesely C, Roseboom I, Larch C, Streicher H, Straatman K, Flynn H, Skehel M, Hirota T, Kuriyama R, Hochegger H. Differential control of Eg5-dependent centrosome separation by Plk1 and Cdk1. EMBO J 2011; 30:2233-45. [PMID: 21522128 PMCID: PMC3117641 DOI: 10.1038/emboj.2011.120] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 03/25/2011] [Indexed: 11/29/2022] Open
Abstract
Cyclin-dependent kinase 1 (Cdk1) is thought to trigger centrosome separation in late G2 phase by phosphorylating the motor protein Eg5 at Thr927. However, the precise control mechanism of centrosome separation remains to be understood. Here, we report that in G2 phase polo-like kinase 1 (Plk1) can trigger centrosome separation independently of Cdk1. We find that Plk1 is required for both C-Nap1 displacement and for Eg5 localization on the centrosome. Moreover, Cdk2 compensates for Cdk1, and phosphorylates Eg5 at Thr927. Nevertheless, Plk1-driven centrosome separation is slow and staggering, while Cdk1 triggers fast movement of the centrosomes. We find that actin-dependent Eg5-opposing forces slow down separation in G2 phase. Strikingly, actin depolymerization, as well as destabilization of interphase microtubules (MTs), is sufficient to remove this obstruction and to speed up Plk1-dependent separation. Conversely, MT stabilization in mitosis slows down Cdk1-dependent centrosome movement. Our findings implicate the modulation of MT stability in G2 and M phase as a regulatory element in the control of centrosome separation.
Collapse
Affiliation(s)
- Ewan Smith
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Nadia Hégarat
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Clare Vesely
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| | - Isaac Roseboom
- Department of Physics and Astronomy, University of Sussex, Brigthon, UK
| | - Chris Larch
- Department of Chemistry and Biochemistry, University of Sussex, Brighton, UK
| | - Hansjörg Streicher
- Department of Chemistry and Biochemistry, University of Sussex, Brighton, UK
| | | | - Helen Flynn
- CRUK London Research Institutes Clare Hall, South Mimms, UK
| | - Mark Skehel
- CRUK London Research Institutes Clare Hall, South Mimms, UK
| | - Toru Hirota
- The Cancer Institute, Japanese Foundation for Cancer Research, Ariake, Tokyo, Japan
| | - Ryoko Kuriyama
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Helfrid Hochegger
- Genome Damage and Stability Centre, University of Sussex, Brighton, UK
| |
Collapse
|
66
|
Kimura K, Kimura A. A novel mechanism of microtubule length-dependent force to pull centrosomes toward the cell center. BIOARCHITECTURE 2011; 1:74-79. [PMID: 21866267 PMCID: PMC3158624 DOI: 10.4161/bioa.1.2.15549] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 03/21/2011] [Indexed: 12/29/2022]
Abstract
The centrosome is a major microtubule-organizing center in animal cells, and its intracellular positioning is critical for defining intracellular architecture. The centrosome positions itself at the cell center. Centrosome centration depends on the microtubule cytoskeleton. To accomplish robust centration regardless of the cell size or cell shape, it has been assumed that the force mediated by the microtubules depends on microtubule length. However, a concrete mechanism to generate forces to pull the centrosome in a microtubule length-dependent manner has been elusive. Recently, we successfully demonstrated that centrosome-directed movement of intracellular organelles along microtubules drives centrosome centration in the Caenorhabditis elegans early embryo. Based on this observation, we proposed the centrosome-organelle mutual pulling model in which the reaction forces of organelle transport generated along microtubules act as a driving force that pulls the centrosomes toward the cell center. This is the first experiment-based model that accounts for the microtubule length-dependent pulling force generated in the cytoplasm contributing to centrosome centration. Intriguingly, this model is consistent with a recent estimation that the pulling force is proportional to the cubic length of microtubules.
Collapse
Affiliation(s)
- Kenji Kimura
- Cell Architecture Laboratory; Center for Frontier Research; National Institute of Genetics; Mishima, Japan
| | | |
Collapse
|
67
|
Théry M. Micropatterning as a tool to decipher cell morphogenesis and functions. J Cell Sci 2010; 123:4201-13. [DOI: 10.1242/jcs.075150] [Citation(s) in RCA: 530] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In situ, cells are highly sensitive to geometrical and mechanical constraints from their microenvironment. These parameters are, however, uncontrolled under classic culture conditions, which are thus highly artefactual. Micro-engineering techniques provide tools to modify the chemical properties of cell culture substrates at sub-cellular scales. These can be used to restrict the location and shape of the substrate regions, in which cells can attach, so-called micropatterns. Recent progress in micropatterning techniques has enabled the control of most of the crucial parameters of the cell microenvironment. Engineered micropatterns can provide a micrometer-scale, soft, 3-dimensional, complex and dynamic microenvironment for individual cells or for multi-cellular arrangements. Although artificial, micropatterned substrates allow the reconstitution of physiological in situ conditions for controlled in vitro cell culture and have been used to reveal fundamental cell morphogenetic processes as highlighted in this review. By manipulating micropattern shapes, cells were shown to precisely adapt their cytoskeleton architecture to the geometry of their microenvironment. Remodelling of actin and microtubule networks participates in the adaptation of the entire cell polarity with respect to external constraints. These modifications further impact cell migration, growth and differentiation.
Collapse
Affiliation(s)
- Manuel Théry
- Laboratoire de Physiologie Cellulaire et Végétale, iRTSV, CEA/CNRS/UJF/INRA, 17 Rue des Martyrs, 38054, Grenoble, France
| |
Collapse
|