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Thiagarajan R, Inamdar MM, Riveline D. Interplay between cell height variations and planar pulsations in epithelial monolayers. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:49. [PMID: 35587840 DOI: 10.1140/epje/s10189-022-00201-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Biological tissues change their shapes through collective interactions of cells. This coordination sets length and time scales for dynamics where precision is essential, in particular during morphogenetic events. However, how these scales emerge remains unclear. Here, we address this question using the pulsatile domains observed in confluent epithelial MDCK monolayers where cells exhibit synchronous contraction and extension cycles of [Formula: see text] h duration and [Formula: see text] length scale. We report that the monolayer thickness changes gradually in space and time by more than twofold in order to counterbalance the contraction and extension of the incompressible cytoplasm. We recapitulate these pulsatile dynamics using a continuum model and show that incorporation of cell stiffness dependent height variations is critical both for generating temporal pulsations and establishing the domain size. We propose that this feedback between height and mechanics could be important in coordinating the length scales of tissue dynamics.
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Affiliation(s)
- Raghavan Thiagarajan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Laboratory of Cell Physics ISIS/IGBMC, CNRS, Université de Strasbourg, Strasbourg, France
- UMR7104, Centre National de la Recherche Scientifique, Illkirch, France
- U964, Institut National de la Santé et de la Recherche Médicale, Illkirch, France
| | - Mandar M Inamdar
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | - Daniel Riveline
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.
- Laboratory of Cell Physics ISIS/IGBMC, CNRS, Université de Strasbourg, Strasbourg, France.
- UMR7104, Centre National de la Recherche Scientifique, Illkirch, France.
- U964, Institut National de la Santé et de la Recherche Médicale, Illkirch, France.
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2
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Nguyen LTS, Robinson DN. The Unusual Suspects in Cytokinesis: Fitting the Pieces Together. Front Cell Dev Biol 2020; 8:441. [PMID: 32626704 PMCID: PMC7314909 DOI: 10.3389/fcell.2020.00441] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/11/2020] [Indexed: 01/24/2023] Open
Abstract
Cytokinesis is the step of the cell cycle in which the cell must faithfully separate the chromosomes and cytoplasm, yielding two daughter cells. The assembly and contraction of the contractile network is spatially and temporally coupled with the formation of the mitotic spindle to ensure the successful completion of cytokinesis. While decades of studies have elucidated the components of this machinery, the so-called usual suspects, and their functions, many lines of evidence are pointing to other unexpected proteins and sub-cellular systems as also being involved in cytokinesis. These we term the unusual suspects. In this review, we introduce recent discoveries on some of these new unusual suspects and begin to consider how these subcellular systems snap together to help complete the puzzle of cytokinesis.
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Affiliation(s)
- Ly T. S. Nguyen
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Douglas N. Robinson
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Chemical and Biomolecular Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, MD, United States
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3
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Abstract
Cytokinesis, a model cell shape change event, is controlled by an integrated system that coordinates the mitotic spindle signals with a mechanoresponsive cytoskeletal network that drives contractility and furrow ingression. Quantitative methods that measure cell mechanics, mechanoresponse (mechanical stress-induced protein accumulation), protein dynamics, and molecular interactions are necessary to provide insight into both the mechanical and biochemical components involved in cytokinesis and cell shape regulation. Micropipette aspiration, fluorescence correlation and cross-correlation spectroscopy, and fluorescence recovery after photobleaching are valuable methods for measuring cell mechanics and protein dynamics in vivo that occur on nanometer to micron length-scales, and microsecond to minute timescales. Collectively, these methods provide the ability to quantify the molecular interactions that control the cell's ability to change shape and undergo cytokinesis.
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4
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Mohan K, Luo T, Robinson DN, Iglesias PA. Cell shape regulation through mechanosensory feedback control. J R Soc Interface 2016. [PMID: 26224568 DOI: 10.1098/rsif.2015.0512] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cells undergo controlled changes in morphology in response to intracellular and extracellular signals. These changes require a means for sensing and interpreting the signalling cues, for generating the forces that act on the cell's physical material, and a control system to regulate this process. Experiments on Dictyostelium amoebae have shown that force-generating proteins can localize in response to external mechanical perturbations. This mechanosensing, and the ensuing mechanical feedback, plays an important role in minimizing the effect of mechanical disturbances in the course of changes in cell shape, especially during cell division, and likely in other contexts, such as during three-dimensional migration. Owing to the complexity of the feedback system, which couples mechanical and biochemical signals involved in shape regulation, theoretical approaches can guide further investigation by providing insights that are difficult to decipher experimentally. Here, we present a computational model that explains the different mechanosensory and mechanoresponsive behaviours observed in Dictyostelium cells. The model features a multiscale description of myosin II bipolar thick filament assembly that includes cooperative and force-dependent myosin-actin binding, and identifies the feedback mechanisms hidden in the observed mechanoresponsive behaviours of Dictyostelium cells during micropipette aspiration experiments. These feedbacks provide a mechanistic explanation of cellular retraction and hence cell shape regulation.
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Affiliation(s)
- Krithika Mohan
- Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Tianzhi Luo
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Douglas N Robinson
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Pablo A Iglesias
- Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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5
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Zangle TA, Teitell MA, Reed J. Live cell interferometry quantifies dynamics of biomass partitioning during cytokinesis. PLoS One 2014; 9:e115726. [PMID: 25531652 PMCID: PMC4274116 DOI: 10.1371/journal.pone.0115726] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 11/27/2014] [Indexed: 12/19/2022] Open
Abstract
The equal partitioning of cell mass between daughters is the usual and expected outcome of cytokinesis for self-renewing cells. However, most studies of partitioning during cell division have focused on daughter cell shape symmetry or segregation of chromosomes. Here, we use live cell interferometry (LCI) to quantify the partitioning of daughter cell mass during and following cytokinesis. We use adherent and non-adherent mouse fibroblast and mouse and human lymphocyte cell lines as models and show that, on average, mass asymmetries present at the time of cleavage furrow formation persist through cytokinesis. The addition of multiple cytoskeleton-disrupting agents leads to increased asymmetry in mass partitioning which suggests the absence of active mass partitioning mechanisms after cleavage furrow positioning.
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Affiliation(s)
- Thomas A. Zangle
- Department of Bioengineering, University of California Los Angeles (UCLA), Los Angeles, California, United States of America
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California, United States of America
- * E-mail: (TAZ); (JR)
| | - Michael A. Teitell
- Department of Bioengineering, University of California Los Angeles (UCLA), Los Angeles, California, United States of America
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California, United States of America
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- California NanoSystems Institute, UCLA, Los Angeles, California, United States of America
- Broad Stem Cell Research Center, UCLA, Los Angeles, California, United States of America
- Molecular Biology Institute, UCLA, Los Angeles, California, United States of America
| | - Jason Reed
- Department of Physics, Virginia Commonwealth University (VCU), Richmond, Virginia, United States of America
- VCU Massey Cancer Center, Richmond, Virginia, United States of America
- * E-mail: (TAZ); (JR)
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6
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Ren Y, West-Foyle H, Surcel A, Miller C, Robinson DN. Genetic suppression of a phosphomimic myosin II identifies system-level factors that promote myosin II cleavage furrow accumulation. Mol Biol Cell 2014; 25:4150-65. [PMID: 25318674 PMCID: PMC4263456 DOI: 10.1091/mbc.e14-08-1322] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
How myosin II localizes to the cleavage furrow in Dictyostelium and metazoan cells remains largely unknown despite significant advances in understanding its regulation. We designed a genetic selection using cDNA library suppression of 3xAsp myosin II to identify factors involved in myosin cleavage furrow accumulation. The 3xAsp mutant is deficient in bipolar thick filament assembly, fails to accumulate at the cleavage furrow, cannot rescue myoII-null cytokinesis, and has impaired mechanosensitive accumulation. Eleven genes suppressed this dominant cytokinesis deficiency when 3xAsp was expressed in wild-type cells. 3xAsp myosin II's localization to the cleavage furrow was rescued by constructs encoding rcdBB, mmsdh, RMD1, actin, one novel protein, and a 14-3-3 hairpin. Further characterization showed that RMD1 is required for myosin II cleavage furrow accumulation, acting in parallel with mechanical stress. Analysis of several mutant strains revealed that different thresholds of myosin II activity are required for daughter cell symmetry than for furrow ingression dynamics. Finally, an engineered myosin II with a longer lever arm (2xELC), producing a highly mechanosensitive motor, could also partially suppress the intragenic 3xAsp. Overall, myosin II accumulation is the result of multiple parallel and partially redundant pathways that comprise a cellular contractility control system.
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Affiliation(s)
- Yixin Ren
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Hoku West-Foyle
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Alexandra Surcel
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Christopher Miller
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 Summer Academic Research Experience, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Douglas N Robinson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205 Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205 Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218
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7
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Satoh SK, Tsuchi A, Satoh R, Miyoshi H, Hamaguchi MS, Hamaguchi Y. The tension at the top of the animal pole decreases during meiotic cell division. PLoS One 2013; 8:e79389. [PMID: 24260212 PMCID: PMC3832532 DOI: 10.1371/journal.pone.0079389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 09/20/2013] [Indexed: 11/18/2022] Open
Abstract
Meiotic maturation is essential for the reproduction procedure of many animals. During this process an oocyte produces a large egg cell and tiny polar bodies by highly asymmetric division. In this study, to fully understand the sophisticated spatiotemporal regulation of accurate oocyte meiotic division, we focused on the global and local changes in the tension at the surface of the starfish (Asterina pectinifera) oocyte in relation to the surface actin remodeling. Before the onset of the bulge formation, the tension at the animal pole globally decreased, and started to increase after the onset of the bulge formation. Locally, at the onset of the bulge formation, tension at the top of the animal pole began to decrease, whereas that at the base of the bulge remarkably increased. As the bulge grew, the tension at the base of the bulge additionally increased. Such a change in the tension at the surface was similar to the changing pattern of actin distribution. Therefore, meiotic cell division was initiated by the bulging of the cortex, which had been weakened by actin reduction, and was followed by contraction at the base of the bulge, which had been reinforced by actin accumulation. The force generation system is assumed to allow the meiotic apparatus to move just under the membrane in the small polar body. Furthermore, a detailed comparison of the tension at the surface and the cortical actin distribution indicated another sophisticated feature, namely that the contraction at the base of the bulge was more vigorous than was presumed based on the actin distribution. These features of the force generation system will ensure the precise chromosome segregation necessary to produce a normal ovum with high accuracy in the meiotic maturation.
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Affiliation(s)
- Setsuko K. Satoh
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
| | - Akifumi Tsuchi
- Faculty of Economics and management, Surugadai University, Hanno, Saitama, Japan
| | - Ryohei Satoh
- Department of Physiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Hiromi Miyoshi
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
- Ultrahigh Precision Optics Technology Team, RIKEN Center for Advanced Photonics, Wako, Saitama, Japan
| | - Miyako S. Hamaguchi
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
| | - Yukihisa Hamaguchi
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro, Tokyo, Japan
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8
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Lafaurie-Janvore J. [Temporal regulation of abscission, the last step of cell division]. Biol Aujourdhui 2013; 207:133-148. [PMID: 24103343 DOI: 10.1051/jbio/2013010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Indexed: 06/02/2023]
Abstract
Cell division is one of the most tightly controlled steps of the cell cycle. Indeed, the many steps of cell division have to be perfectly coordinated both in time and space in order to ensure an error-free division and an accurate transmission of the genome from the mother cell to the two daughter cells. Abscission, the last step of cytokinesis, consists in the severing of the intercellular bridge that connects the two daughter cells after the contraction of the acto-myosin ring. As is the case for any other step of cell division, abscission has to be precisely regulated in order to take place at the right time and the proper place. Whereas the spatial regulation of abscission is quite well understood, the study of temporal regulation is in its infancy. This review begins by describing the formation of the intercellular bridge, its organization, and its composition. Next the different models of abscission are discussed. Finally, the current understanding of the temporal regulation of abscission is detailed. In particular, I present my recent results on the role of forces exerted by the daughter cells on the intercellular bridge.
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9
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Corda D, Barretta ML, Cervigni RI, Colanzi A. Golgi complex fragmentation in G2/M transition: An organelle-based cell-cycle checkpoint. IUBMB Life 2012; 64:661-70. [PMID: 22730233 DOI: 10.1002/iub.1054] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 04/29/2012] [Indexed: 11/06/2022]
Abstract
In mammalian cells, the Golgi complex is organized into a continuous membranous system known as the Golgi ribbon, which is formed by individual Golgi stacks that are laterally connected by tubular bridges. During mitosis, the Golgi ribbon undergoes extensive fragmentation through a multistage process that is required for its correct partitioning into the daughter cells. Importantly, inhibition of this Golgi disassembly results in cell-cycle arrest at the G2 stage, suggesting that accurate inheritance of the Golgi complex is monitored by a "Golgi mitotic checkpoint." Here, we discuss the mechanisms and regulation of the Golgi ribbon breakdown and briefly comment on how Golgi partitioning may inhibit G2/M transition.
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Affiliation(s)
- Daniela Corda
- Institute of Protein Biochemistry, National Research Council (CNR), Via Pietro Castellino 111, Naples, Italy.
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10
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Fernandez P, Maier M, Lindauer M, Kuffer C, Storchova Z, Bausch AR. Mitotic spindle orients perpendicular to the forces imposed by dynamic shear. PLoS One 2011; 6:e28965. [PMID: 22220200 PMCID: PMC3248423 DOI: 10.1371/journal.pone.0028965] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 11/18/2011] [Indexed: 12/30/2022] Open
Abstract
Orientation of the division axis can determine cell fate in the presence of morphogenetic gradients. Understanding how mitotic cells integrate directional cues is therefore an important question in embryogenesis. Here, we investigate the effect of dynamic shear forces on confined mitotic cells. We found that human epithelial cells (hTERT-RPE1) as well as MC3T3 osteoblasts align their mitotic spindle perpendicular to the external force. Spindle orientation appears to be a consequence of cell elongation along the zero-force direction in response to the dynamic shear. This process is a nonlinear response to the strain amplitude, requires actomyosin activity and correlates with redistribution of myosin II. Mechanosteered cells divide normally, suggesting that this mechanism is compatible with biological functions.
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Affiliation(s)
- Pablo Fernandez
- E27 Zellbiophysik, Technische Universität München, Garching bei München, Germany.
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11
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Uyeda TQP, Iwadate Y, Umeki N, Nagasaki A, Yumura S. Stretching actin filaments within cells enhances their affinity for the myosin II motor domain. PLoS One 2011; 6:e26200. [PMID: 22022566 PMCID: PMC3192770 DOI: 10.1371/journal.pone.0026200] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/22/2011] [Indexed: 11/18/2022] Open
Abstract
To test the hypothesis that the myosin II motor domain (S1) preferentially binds to specific subsets of actin filaments in vivo, we expressed GFP-fused S1 with mutations that enhanced its affinity for actin in Dictyostelium cells. Consistent with the hypothesis, the GFP-S1 mutants were localized along specific portions of the cell cortex. Comparison with rhodamine-phalloidin staining in fixed cells demonstrated that the GFP-S1 probes preferentially bound to actin filaments in the rear cortex and cleavage furrows, where actin filaments are stretched by interaction with endogenous myosin II filaments. The GFP-S1 probes were similarly enriched in the cortex stretched passively by traction forces in the absence of myosin II or by external forces using a microcapillary. The preferential binding of GFP-S1 mutants to stretched actin filaments did not depend on cortexillin I or PTEN, two proteins previously implicated in the recruitment of myosin II filaments to stretched cortex. These results suggested that it is the stretching of the actin filaments itself that increases their affinity for the myosin II motor domain. In contrast, the GFP-fused myosin I motor domain did not localize to stretched actin filaments, which suggests different preferences of the motor domains for different structures of actin filaments play a role in distinct intracellular localizations of myosin I and II. We propose a scheme in which the stretching of actin filaments, the preferential binding of myosin II filaments to stretched actin filaments, and myosin II-dependent contraction form a positive feedback loop that contributes to the stabilization of cell polarity and to the responsiveness of the cells to external mechanical stimuli.
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Affiliation(s)
- Taro Q P Uyeda
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
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12
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Evans JP, Robinson DN. The spatial and mechanical challenges of female meiosis. Mol Reprod Dev 2011; 78:769-77. [PMID: 21774026 PMCID: PMC3196790 DOI: 10.1002/mrd.21358] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 06/15/2011] [Indexed: 12/31/2022]
Abstract
Recent work shows that cytokinesis and other cellular morphogenesis events are tuned by an interplay among biochemical signals, cell shape, and cellular mechanics. In cytokinesis, this includes cross-talk between the cortical cytoskeleton and the mitotic spindle in coordination with cell cycle control, resulting in characteristic changes in cellular morphology and mechanics through metaphase and cytokinesis. The changes in cellular mechanics affect not just overall cell shape, but also mitotic spindle morphology and function. This review will address how these principles apply to oocytes undergoing the asymmetric cell divisions of meiosis I and II. The biochemical signals that regulate cell cycle timing during meiotic maturation and egg activation are crucial for temporal control of meiosis. Spatial control of the meiotic divisions is also important, ensuring that the chromosomes are segregated evenly and that meiotic division is clearly asymmetric, yielding two daughter cells - oocyte and polar body - with enormous volume differences. In contrast to mitotic cells, the oocyte does not undergo overt changes in cell shape with its progression through meiosis, but instead maintains a relatively round morphology with the exception of very localized changes at the time of polar body emission. Placement of the metaphase-I and -II spindles at the oocyte periphery is clearly important for normal polar body emission, although this is likely not the only control element. Here, consideration is given to how cellular mechanics could contribute to successful mammalian female meiosis, ultimately affecting egg quality and competence to form a healthy embryo.
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Affiliation(s)
- Janice P Evans
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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13
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Sedzinski J, Biro M, Oswald A, Tinevez JY, Salbreux G, Paluch E. Polar actomyosin contractility destabilizes the position of the cytokinetic furrow. Nature 2011; 476:462-6. [PMID: 21822289 DOI: 10.1038/nature10286] [Citation(s) in RCA: 240] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 06/13/2011] [Indexed: 12/21/2022]
Abstract
Cytokinesis, the physical separation of daughter cells at the end of mitosis, requires precise regulation of the mechanical properties of the cell periphery. Although studies of cytokinetic mechanics mostly focus on the equatorial constriction ring, a contractile actomyosin cortex is also present at the poles of dividing cells. Whether polar forces influence cytokinetic cell shape and furrow positioning remains an open question. Here we demonstrate that the polar cortex makes cytokinesis inherently unstable. We show that limited asymmetric polar contractions occur during cytokinesis, and that perturbing the polar cortex leads to cell shape oscillations, resulting in furrow displacement and aneuploidy. A theoretical model based on a competition between cortex turnover and contraction dynamics accurately accounts for the oscillations. We further propose that membrane blebs, which commonly form at the poles of dividing cells and whose role in cytokinesis has long been enigmatic, stabilize cell shape by acting as valves releasing cortical contractility. Our findings reveal an inherent instability in the shape of the dividing cell and unveil a novel, spindle-independent mechanism ensuring the stability of cleavage furrow positioning.
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Affiliation(s)
- Jakub Sedzinski
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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14
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Rajagopalan J, Saif MTA. MEMS Sensors and Microsystems for Cell Mechanobiology. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2011; 21:54002-54012. [PMID: 21886944 PMCID: PMC3163288 DOI: 10.1088/0960-1317/21/5/054002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Forces generated by cells play a vital role in many cellular processes like cell spreading, motility, differentiation and apoptosis. Understanding the mechanics of single cells is essential to delineate the link between cellular force generation/sensing and function. MEMS sensors, because of their small size and fine force/displacement resolution, are ideal for force and displacement sensing at the single cell level. In addition, the amenability of MEMS sensors to batch fabrication methods allows the study of large cell populations simultaneously, leading to robust statistical studies. In this review, we discuss various microsystems used for studying cell mechanics and the insights on cell mechanical behavior that have resulted from their use. The advantages and limitations of these microsystems for biological studies are also outlined.
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Affiliation(s)
- Jagannathan Rajagopalan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W Green Street Urbana IL -61801 USA ,
| | - M. Taher A. Saif
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W Green Street Urbana IL -61801 USA ,
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15
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Kim HY, Davidson LA. Punctuated actin contractions during convergent extension and their permissive regulation by the non-canonical Wnt-signaling pathway. J Cell Sci 2011; 124:635-46. [PMID: 21266466 PMCID: PMC3031374 DOI: 10.1242/jcs.067579] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2010] [Indexed: 12/18/2022] Open
Abstract
Actomyosin networks linked to the micro-environment through the plasma membrane are thought to be key players in regulating cell behaviors within multicellular tissues, such as converging and extending mesoderm. Here, we observe the dynamics of actin contractions called 'punctuated actin contractions' in the mid-cell body of embryonic mesenchymal cells in the mesoderm. These contraction dynamics are a common feature of Xenopus embryonic tissues and are important for cell shape changes during morphogenesis. Quantitative morphological analysis of these F-actin dynamics indicates that frequent and aligned movements of multiple actin contractions accompany mesoderm cells as they intercalate and elongate. Using inhibitors combined with fluorescence recovery after photobleaching (FRAP) analysis, we find that the dynamics of actin contractions are regulated by both myosin contractility and F-actin polymerization. Furthermore, we find that the non-canonical Wnt-signaling pathway permissively regulates levels of punctuated actin contractions. Overexpression of Xfz7 (Fzd7) can induce early maturation of actin contractions in mesoderm and produce mesoderm-like actin contractions in ectoderm cells. By contrast, expression of the dominant-negative Xenopus disheveled construct Xdd1 blocks the progression of actin contractions into their late mesoderm dynamics but has no effect in ectoderm. Our study reveals punctuated actin contractions within converging and extending mesoderm and uncovers a permissive role for non-canonical Wnt-signaling, myosin contractility and F-actin polymerization in regulating these dynamics.
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Affiliation(s)
- Hye Young Kim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Lance A. Davidson
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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16
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Surcel A, Kee YS, Luo T, Robinson DN. Cytokinesis through biochemical-mechanical feedback loops. Semin Cell Dev Biol 2010; 21:866-73. [PMID: 20709619 DOI: 10.1016/j.semcdb.2010.08.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 06/22/2010] [Accepted: 08/03/2010] [Indexed: 10/19/2022]
Abstract
Cytokinesis is emerging as a control system defined by interacting biochemical and mechanical modules, which form a system of feedback loops. This integrated system accounts for the regulation and kinetics of cytokinesis furrowing and demonstrates that cytokinesis is a whole-cell process in which the global and equatorial cortices and cytoplasm are active players in the system. Though originally defined in Dictyostelium, features of the control system are recognizable in other organisms, suggesting a universal mechanism for cytokinesis regulation and contractility.
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Affiliation(s)
- Alexandra Surcel
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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17
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Molecular Biomechanics: The Molecular Basis of How Forces Regulate Cellular Function. Cell Mol Bioeng 2010; 3:91-105. [PMID: 20700472 DOI: 10.1007/s12195-010-0109-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Recent advances have led to the emergence of molecular biomechanics as an essential element of modern biology. These efforts focus on theoretical and experimental studies of the mechanics of proteins and nucleic acids, and the understanding of the molecular mechanisms of stress transmission, mechanosensing and mechanotransduction in living cells. In particular, single-molecule biomechanics studies of proteins and DNA, and mechanochemical coupling in biomolecular motors have demonstrated the critical importance of molecular mechanics as a new frontier in bioengineering and life sciences. To stimulate a more systematic study of the basic issues in molecular biomechanics, and attract a broader range of researchers to enter this emerging field, here we discuss its significance and relevance, describe the important issues to be addressed and the most critical questions to be answered, summarize both experimental and theoretical/computational challenges, and identify some short-term and long-term goals for the field. The needs to train young researchers in molecular biomechanics with a broader knowledge base, and to bridge and integrate molecular, subcellular and cellular level studies of biomechanics are articulated.
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Pramanik MK, Iijima M, Iwadate Y, Yumura S. PTEN is a mechanosensing signal transducer for myosin II localization in Dictyostelium cells. Genes Cells 2009; 14:821-34. [PMID: 19515202 DOI: 10.1111/j.1365-2443.2009.01312.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
To investigate the role of PTEN in regulation of cortical motile activity, especially in myosin II localization, eGFP-PTEN and mRFP-myosin II were simultaneously expressed in Dictyostelium cells. PTEN and myosin II co-localized at the posterior of migrating cells and furrow region of dividing cells. In suspension culture, PTEN knockout (pten(-)) cells became multinucleated, and myosin II significantly decreased in amount at the furrow. During pseudopod retraction and cell aspiration by microcapillary, PTEN accumulated at the tips of pseudopods and aspirated lobes prior to the accumulation of myosin II. In pten(-) cells, only a small amount of myosin II accumulated at the retracting pseudopods and aspirated cell lobes. PTEN accumulated at the retracting pseudopods and aspirated lobes even in myosin II null cells and latrunculin B-treated cells though in reduced amounts, indicating that PTEN accumulates partially depending on myosin II and cortical actin. Accumulation of PTEN prior to myosin II suggests that PTEN is an upstream component in signaling pathway to localize myosin II, possibly with mechanosensing signaling loop where actomyosin-driven contraction further augments accumulation of PTEN and myosin II by a positive feedback mechanism.
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Affiliation(s)
- Md Kamruzzaman Pramanik
- Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan
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Affiliation(s)
- Jonathon Howard
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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Yu W, Khandelwal P, Apodaca G. Distinct apical and basolateral membrane requirements for stretch-induced membrane traffic at the apical surface of bladder umbrella cells. Mol Biol Cell 2008; 20:282-95. [PMID: 18987341 DOI: 10.1091/mbc.e08-04-0439] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Epithelial cells respond to mechanical stimuli by increasing exocytosis, endocytosis, and ion transport, but how these processes are initiated and coordinated and the mechanotransduction pathways involved are not well understood. We observed that in response to a dynamic mechanical environment, increased apical membrane tension, but not pressure, stimulated apical membrane exocytosis and ion transport in bladder umbrella cells. The exocytic response was independent of temperature but required the cytoskeleton and the activity of a nonselective cation channel and the epithelial sodium channel. The subsequent increase in basolateral membrane tension had the opposite effect and triggered the compensatory endocytosis of added apical membrane, which was modulated by opening of basolateral K(+) channels. Our results indicate that during the dynamic processes of bladder filling and voiding apical membrane dynamics depend on sequential and coordinated mechanotransduction events at both membrane domains of the umbrella cell.
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Affiliation(s)
- Weiqun Yu
- Laboratory of Epithelial Cell Biology and Renal Electrolyte Division of the Department of Medicine, Department of Bioengineering, University of Pittsburgh, PA 15261, USA
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