1
|
Gurley NJ, Peifer M. Moonwalking molecular machines: Unraveling the choreography of myosin filament assembly. J Cell Biol 2024; 223:e202402093. [PMID: 38429998 PMCID: PMC10904331 DOI: 10.1083/jcb.202402093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024] Open
Abstract
We have made tremendous progress in identifying the machines that shape the architecture of actin filaments. However, we know less about the mechanisms mediating myosin assembly at the supramolecular level. In this issue, Quintanilla et al. (https://doi.org/10.1083/jcb.202305023) provide important new insights into this process.
Collapse
Affiliation(s)
- Noah J. Gurley
- Skaggs Graduate School of Chemical and Biological Sciences, UF Scripps Research Institute, Jupiter, FL, USA
| | - Mark Peifer
- Department of Biology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
2
|
Quintanilla MA, Patel H, Wu H, Sochacki KA, Chandrasekar S, Akamatsu M, Rotty JD, Korobova F, Bear JE, Taraska JW, Oakes PW, Beach JR. Local monomer levels and established filaments potentiate non-muscle myosin 2 assembly. J Cell Biol 2024; 223:e202305023. [PMID: 38353656 PMCID: PMC10866686 DOI: 10.1083/jcb.202305023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 01/02/2024] [Accepted: 01/26/2024] [Indexed: 02/16/2024] Open
Abstract
The ability to dynamically assemble contractile networks is required throughout cell physiology, yet direct biophysical mechanisms regulating non-muscle myosin 2 filament assembly in living cells are lacking. Here, we use a suite of dynamic, quantitative imaging approaches to identify deterministic factors that drive myosin filament appearance and amplification. We find that actin dynamics regulate myosin assembly, but that the static actin architecture plays a less clear role. Instead, remodeling of actin networks modulates the local myosin monomer levels and facilitates assembly through myosin:myosin-driven interactions. Using optogenetically controlled myosin, we demonstrate that locally concentrating myosin is sufficient to both form filaments and jump-start filament amplification and partitioning. By counting myosin monomers within filaments, we demonstrate a myosin-facilitated assembly process that establishes filament stacks prior to partitioning into clusters that feed higher-order networks. Together, these findings establish the biophysical mechanisms regulating the assembly of non-muscle contractile structures that are ubiquitous throughout cell biology.
Collapse
Affiliation(s)
- Melissa A. Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Hiral Patel
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Huini Wu
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Kem A. Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shreya Chandrasekar
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Matthew Akamatsu
- Department of Biology, University of Washington, Seattle, WA, USA
| | - Jeremy D. Rotty
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Farida Korobova
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA
| | - Justin W. Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Patrick W. Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Jordan R. Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| |
Collapse
|
3
|
Heydecker M, Shitara A, Chen D, Tran D, Masedunskas A, Tora M, Ebrahim S, Appaduray MA, Galeano Niño JL, Bhardwaj A, Narayan K, Hardeman EC, Gunning PW, Weigert R. Spatial and Temporal Coordination of Force-generating Actin-based Modules Drives Membrane Remodeling In Vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.569944. [PMID: 38168275 PMCID: PMC10760165 DOI: 10.1101/2023.12.04.569944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Membrane remodeling drives a broad spectrum of cellular functions, and it is regulated through mechanical forces exerted on the membrane by cytoplasmic complexes. Here, we investigate how actin filaments dynamically tune their structure to control the active transfer of membranes between cellular compartments with distinct compositions and biophysical properties. Using intravital subcellular microscopy in live rodents we show that: a lattice composed of linear filaments stabilizes the granule membrane after fusion with the plasma membrane; and a network of branched filaments linked to the membranes by Ezrin, a regulator of membrane tension, initiates and drives to completion the integration step. Our results highlight how the actin cytoskeleton tunes its structure to adapt to dynamic changes in the biophysical properties of membranes.
Collapse
|
4
|
Arima T, Okita K, Yumura S. Dynamics of actomyosin filaments in the contractile ring revealed by ultrastructural analysis. Genes Cells 2023; 28:845-856. [PMID: 37844904 DOI: 10.1111/gtc.13073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023]
Abstract
Cytokinesis, the final process of cell division, involves the accumulation of actin and myosin II filaments at the cell's equator, forming a contractile ring that facilitates the division into two daughter cells. While light microscopy has provided valuable insights into the molecular mechanism of this process, it has limitations in examining individual filaments in vivo. In this study, we utilized transmission electron microscopy to observe actin and myosin II filaments in the contractile rings of dividing Dictyostelium cells. To synchronize cytokinesis, we developed a novel method that allowed us to visualize dividing cells undergoing cytokinesis with a frequency as high as 18%. This improvement enabled us to examine the lengths and alignments of individual filaments within the contractile rings. As the furrow constricted, the length of actin filaments gradually decreased. Moreover, both actin and myosin II filaments reoriented perpendicularly to the long axis during furrow constriction. Through experiments involving myosin II null cells, we discovered that myosin II plays a role in regulating both the lengths and alignments of actin filaments. Additionally, dynamin-like protein A was found to contribute to regulating the length of actin filaments, while cortexillins were involved in regulating their alignment.
Collapse
Affiliation(s)
- Takeru Arima
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Keisuke Okita
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Shigehiko Yumura
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| |
Collapse
|
5
|
Lebedev M, Chan FY, Lochner A, Bellessem J, Osório DS, Rackles E, Mikeladze-Dvali T, Carvalho AX, Zanin E. Anillin forms linear structures and facilitates furrow ingression after septin and formin depletion. Cell Rep 2023; 42:113076. [PMID: 37665665 PMCID: PMC10548094 DOI: 10.1016/j.celrep.2023.113076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 07/13/2023] [Accepted: 08/16/2023] [Indexed: 09/06/2023] Open
Abstract
During cytokinesis, a contractile ring consisting of unbranched filamentous actin (F-actin) and myosin II constricts at the cell equator. Unbranched F-actin is generated by formin, and without formin no cleavage furrow forms. In Caenorhabditis elegans, depletion of septin restores furrow ingression in formin mutants. How the cleavage furrow ingresses without a detectable unbranched F-actin ring is unknown. We report that, in this setting, anillin (ANI-1) forms a meshwork of circumferentially aligned linear structures decorated by non-muscle myosin II (NMY-2). Analysis of ANI-1 deletion mutants reveals that its disordered N-terminal half is required for linear structure formation and sufficient for furrow ingression. NMY-2 promotes the circumferential alignment of the linear ANI-1 structures and interacts with various lipids, suggesting that NMY-2 links the ANI-1 network with the plasma membrane. Collectively, our data reveal a compensatory mechanism, mediated by ANI-1 linear structures and membrane-bound NMY-2, that promotes furrowing when unbranched F-actin polymerization is compromised.
Collapse
Affiliation(s)
- Mikhail Lebedev
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany; Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
| | - Fung-Yi Chan
- i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Anna Lochner
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany
| | - Jennifer Bellessem
- Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
| | - Daniel S Osório
- i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Elisabeth Rackles
- Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
| | - Tamara Mikeladze-Dvali
- Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
| | - Ana Xavier Carvalho
- i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Esther Zanin
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany; Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany.
| |
Collapse
|
6
|
Cortes DB, Maddox PS, Nédéléç FJ, Maddox AS. Contractile ring composition dictates kinetics of in silico contractility. Biophys J 2023; 122:3611-3629. [PMID: 36540027 PMCID: PMC10541479 DOI: 10.1016/j.bpj.2022.12.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/12/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Constriction kinetics of the cytokinetic ring are expected to depend on dynamic adjustment of contractile ring composition, but the impact of ring component abundance dynamics on ring constriction is understudied. Computational models generally assume that contractile networks maintain constant total amounts of components, which is not always true. To test how compositional dynamics affect constriction kinetics, we first measured F-actin, non-muscle myosin II, septin, and anillin during Caenorhabditis elegans zygotic mitosis. A custom microfluidic device that positioned the cell with the division plane parallel to a light sheet allowed even illumination of the cytokinetic ring. Measured component abundances were implemented in a three-dimensional agent-based model of a membrane-associated contractile ring. With constant network component amounts, constriction completed with biologically unrealistic kinetics. However, imposing the measured changes in component quantities allowed this model to elicit realistic constriction kinetics. Simulated networks were more sensitive to changes in motor and filament amounts than those of crosslinkers and tethers. Our findings highlight the importance of network composition for actomyosin contraction kinetics.
Collapse
Affiliation(s)
- Daniel B Cortes
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.
| | - Paul S Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Francois J Nédéléç
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Amy Shaub Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.
| |
Collapse
|
7
|
Xiao L, Pang J, Qin H, Dou L, Yang M, Wang J, Zhou X, Li Y, Duan J, Sun Z. Amorphous silica nanoparticles cause abnormal cytokinesis and multinucleation through dysfunction of the centralspindlin complex and microfilaments. Part Fibre Toxicol 2023; 20:34. [PMID: 37608338 PMCID: PMC10464468 DOI: 10.1186/s12989-023-00544-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 07/18/2023] [Indexed: 08/24/2023] Open
Abstract
BACKGROUND With the large-scale production and application of amorphous silica nanoparticles (aSiNPs), its adverse health effects are more worthy of our attention. Our previous research has demonstrated for the first time that aSiNPs induced cytokinesis failure, which resulted in abnormally high incidences of multinucleation in vitro, but the underlying mechanisms remain unclear. Therefore, the purpose of this study was firstly to explore whether aSiNPs induced multinucleation in vivo, and secondly to investigate the underlying mechanism of how aSiNPs caused abnormal cytokinesis and multinucleation. METHODS Male ICR mice with intratracheal instillation of aSiNPs were used as an experimental model in vivo. Human hepatic cell line (L-02) was introduced for further mechanism study in vitro. RESULTS In vivo, histopathological results showed that the rate of multinucleation was significantly increased in the liver and lung tissue after aSiNPs treatment. In vitro, immunofluorescence results manifested that aSiNPs directly caused microfilaments aggregation. Following mechanism studies indicated that aSiNPs increased ROS levels. The accumulation of ROS further inhibited the PI3k 110β/Aurora B pathway, leading to a decrease in the expression of centralspindlin subunits MKLP1 and CYK4 as well as downstream cytokines regulation related proteins Ect2, Cep55, CHMP2A and RhoA. Meanwhile, the particles caused abnormal co-localization of the key mitotic regulatory kinase Aurora B and the centralspindlin complex by inhibiting the PI3k 110β/Aurora B pathway. PI3K activator IGF increased the phosphorylation level of Aurora B and improved the relative ratio of the centralspindlin cluster. And ROS inhibitors NAC reduced the ratio of multinucleation, alleviated the PI3k 110β/Aurora B pathway inhibition, and then increased the expression of MKLP1, CYK4 and cytokinesis-related proteins, whilst NAC restored the clustering of the centralspindlin. CONCLUSION This study demonstrated that aSiNPs led to multinucleation formation both in vivo and in vitro. ASiNPs exposure caused microfilaments aggregation and inhibited the PI3k 110β/Aurora B pathway through excessive ROS, which then hindered the centralspindlin cluster as well as restrained the expression of centralspindlin subunits and cytokinesis-related proteins, which ultimately resulted in cytokinesis failure and the formation of multinucleation.
Collapse
Affiliation(s)
- Liyan Xiao
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Jinyan Pang
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Hua Qin
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
- Department of Chemistry, College of Sciences, Northeastern University, 110819, Shenyang, P.R. China
| | - Liyang Dou
- Department of Geriatric Medicine, Medical Health Center, Beijing Friendship Hospital, Capital Medical University, 100050, Beijing, P.R. China
| | - Man Yang
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Ji Wang
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Xianqing Zhou
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Yang Li
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China.
| | - Junchao Duan
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| | - Zhiwei Sun
- Beijing Key Laboratory of Environmental Toxicology, School of Public Health, Capital Medical University, Beijing, 100069, P.R. China
| |
Collapse
|
8
|
Quintanilla MA, Patel H, Wu H, Sochacki KA, Akamatsu M, Rotty JD, Korobova F, Bear JE, Taraska JW, Oakes PW, Beach JR. Local Monomer Levels and Established Filaments Potentiate Non-Muscle Myosin 2 Assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538303. [PMID: 37162845 PMCID: PMC10168331 DOI: 10.1101/2023.04.26.538303] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The ability to dynamically assemble contractile networks is required throughout cell physiology, yet the biophysical mechanisms regulating non-muscle myosin 2 filament assembly in living cells are lacking. Here we use a suite of dynamic, quantitative imaging approaches to identify deterministic factors that drive myosin filament appearance and amplification. We find that actin dynamics regulate myosin assembly, but that the actin architecture plays a minimal direct role. Instead, remodeling of actin networks modulates the local myosin monomer levels and facilitates assembly through myosin:myosin driven interactions. Using optogenetically controlled myosin, we demonstrate that locally concentrating myosin is sufficient to both form filaments and jump-start filament amplification and partitioning. By counting myosin monomers within filaments, we demonstrate a myosin-facilitated assembly process that establishes sub-resolution filament stacks prior to partitioning into clusters that feed higher-order networks. Together these findings establish the biophysical mechanisms regulating the assembly of non-muscle contractile structures that are ubiquitous throughout cell biology.
Collapse
Affiliation(s)
- Melissa A Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Hiral Patel
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Huini Wu
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | | | - Jeremy D Rotty
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Farida Korobova
- Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - James E Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill, Chapel Hill, NC
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Patrick W Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Jordan R Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| |
Collapse
|
9
|
Abstract
Non-muscle myosin 2 (NM2) motors are the major contractile machines in most cell types. Unsurprisingly, these ubiquitously expressed actin-based motors power a plethora of subcellular, cellular and multicellular processes. In this Cell Science at a Glance article and the accompanying poster, we review the biochemical properties and mechanisms of regulation of this myosin. We highlight the central role of NM2 in multiple fundamental cellular processes, which include cell migration, cytokinesis, epithelial barrier function and tissue morphogenesis. In addition, we highlight recent studies using advanced imaging technologies that have revealed aspects of NM2 assembly hitherto inaccessible. This article will hopefully appeal to both cytoskeletal enthusiasts and investigators from outside the cytoskeleton field who have interests in one of the many basic cellular processes requiring actomyosin force production.
Collapse
Affiliation(s)
- Melissa A. Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60525, USA
| | - John A. Hammer
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jordan R. Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60525, USA
| |
Collapse
|
10
|
Abstract
One of the major challenges of bottom-up synthetic biology is rebuilding a minimal cell division machinery. From a reconstitution perspective, the animal cell division apparatus is mechanically the simplest and therefore attractive to rebuild. An actin-based ring produces contractile force to constrict the membrane. By contrast, microbes and plant cells have a cell wall, so division requires concerted membrane constriction and cell wall synthesis. Furthermore, reconstitution of the actin division machinery helps in understanding the physical and molecular mechanisms of cytokinesis in animal cells and thus our own cells. In this review, we describe the state-of-the-art research on reconstitution of minimal actin-mediated cytokinetic machineries. Based on the conceptual requirements that we obtained from the physics of the shape changes involved in cell division, we propose two major routes for building a minimal actin apparatus capable of division. Importantly, we acknowledge both the passive and active roles that the confining lipid membrane can play in synthetic cytokinesis. We conclude this review by identifying the most pressing challenges for future reconstitution work, thereby laying out a roadmap for building a synthetic cell equipped with a minimal actin division machinery.
Collapse
|
11
|
Silva AM, Chan FY, Norman MJ, Sobral AF, Zanin E, Gassmann R, Belmonte JM, Carvalho AX. β-heavy-spectrin stabilizes the constricting contractile ring during cytokinesis. J Cell Biol 2022; 222:213538. [PMID: 36219157 PMCID: PMC9559602 DOI: 10.1083/jcb.202202024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 08/17/2022] [Accepted: 09/20/2022] [Indexed: 11/22/2022] Open
Abstract
Cytokinesis requires the constriction of an actomyosin-based contractile ring and involves multiple F-actin crosslinkers. We show that partial depletion of the C. elegans cytokinetic formin generates contractile rings with low F-actin levels that constrict but are structurally fragile, and we use this background to investigate the roles of the crosslinkers plastin/PLST-1 and β-heavy-spectrin/SMA-1 during ring constriction. We show that the removal of PLST-1 or SMA-1 has opposite effects on the structural integrity of fragile rings. PLST-1 loss reduces cortical tension that resists ring constriction and makes fragile rings less prone to ruptures and regressions, whereas SMA-1 loss exacerbates structural defects, leading to frequent ruptures and cytokinesis failure. Fragile rings without SMA-1 or containing a shorter SMA-1, repeatedly rupture at the same site, and SMA-1::GFP accumulates at repair sites in fragile rings and in rings cut by laser microsurgery. These results establish that β-heavy-spectrin stabilizes the constricting ring and reveals the importance of β-heavy-spectrin size for network connectivity at low F-actin density.
Collapse
Affiliation(s)
- Ana Marta Silva
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Fung-Yi Chan
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Michael J. Norman
- Department of Physics, North Carolina State University, Raleigh, NC,Quantitative and Computational Developmental Biology Cluster, North Carolina State University, Raleigh, NC
| | - Ana Filipa Sobral
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Esther Zanin
- Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Reto Gassmann
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Julio Monti Belmonte
- Department of Physics, North Carolina State University, Raleigh, NC,Quantitative and Computational Developmental Biology Cluster, North Carolina State University, Raleigh, NC
| | - Ana Xavier Carvalho
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal,Correspondence to Ana Xavier Carvalho:
| |
Collapse
|
12
|
Sayyad WA, Pollard TD. The number of cytokinesis nodes in mitotic fission yeast scales with cell size. eLife 2022; 11:76249. [PMID: 36093997 PMCID: PMC9467510 DOI: 10.7554/elife.76249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 08/18/2022] [Indexed: 11/22/2022] Open
Abstract
Cytokinesis nodes are assemblies of stoichiometric ratios of proteins associated with the plasma membrane, which serve as precursors for the contractile ring during cytokinesis by fission yeast. The total number of nodes is uncertain, because of the limitations of the methods used previously. Here, we used the ~140 nm resolution of Airyscan super-resolution microscopy to measure the fluorescence intensity of small, single cytokinesis nodes marked with Blt1-mEGFP in live fission yeast cells early in mitosis. The ratio of the total Blt1-mEGFP fluorescence in the broad band of cytokinesis nodes to the average fluorescence of a single node gives about 190 single cytokinesis nodes in wild-type fission yeast cells early in mitosis. Most, but not all of these nodes condense into a contractile ring. The number of cytokinesis nodes scales with cell size in four strains tested, although large diameter rga4Δ mutant cells form somewhat fewer cytokinesis nodes than expected from the overall trend. The Pom1 kinase restricts cytokinesis nodes from the ends of cells, but the surface density of Pom1 on the plasma membrane around the equators of cells is similar with a wide range of node numbers, so Pom1 does not control cytokinesis node number. However, when the concentrations of either kinase Pom1 or kinase Cdr2 were varied with the nmt1 promoter, the numbers of cytokinesis nodes increased above a baseline of about ~190 with the total cellular concentration of either kinase.
Collapse
Affiliation(s)
- Wasim A Sayyad
- Department of Molecular Cellular and Developmental Biology,Yale University, New Haven, United States
| | - Thomas D Pollard
- Department of Molecular Cellular and Developmental Biology,Yale University, New Haven, United States.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States.,Department of Cell Biology,Yale University, New Haven, United States
| |
Collapse
|
13
|
Abstract
The cytoskeleton is a complex of detergent-insoluble components of the cytoplasm playing critical roles in cell motility, shape generation, and mechanical properties of a cell. Fibrillar polymers-actin filaments, microtubules, and intermediate filaments-are major constituents of the cytoskeleton, which constantly change their organization during cellular activities. The actin cytoskeleton is especially polymorphic, as actin filaments can form multiple higher-order assemblies performing different functions. Structural information about cytoskeleton organization is critical for understanding its functions and mechanisms underlying various forms of cellular activity. Because of the nanometer-scale thickness of cytoskeletal fibers, electron microscopy (EM) is a key tool to determine the structure of the cytoskeleton.This article describes application of rotary shadowing (or platinum replica ) EM (PREM) for visualization of the cytoskeleton . The procedure is applicable to thin cultured cells growing on glass coverslips and consists of detergent extraction (or mechanical "unroofing") of cells to expose their cytoskeleton , chemical fixation to provide stability, ethanol dehydration and critical point drying to preserve three-dimensionality, rotary shadowing with platinum to create contrast, and carbon coating to stabilize replicas. This technique provides easily interpretable three-dimensional images, in which individual cytoskeletal fibers are clearly resolved and individual proteins can be identified by immunogold labeling. More importantly, PREM is easily compatible with live cell imaging, so that one can correlate the dynamics of a cell or its components, e.g., expressed fluorescent proteins, with high-resolution structural organization of the cytoskeleton in the same cell.
Collapse
Affiliation(s)
- Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
14
|
Garno C, Irons ZH, Gamache CM, McKim Q, Reyes G, Wu X, Shuster CB, Henson JH. Building the cytokinetic contractile ring in an early embryo: Initiation as clusters of myosin II, anillin and septin, and visualization of a septin filament network. PLoS One 2021; 16:e0252845. [PMID: 34962917 PMCID: PMC8714119 DOI: 10.1371/journal.pone.0252845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/24/2021] [Indexed: 01/15/2023] Open
Abstract
The cytokinetic contractile ring (CR) was first described some 50 years ago, however our understanding of the assembly and structure of the animal cell CR remains incomplete. We recently reported that mature CRs in sea urchin embryos contain myosin II mini-filaments organized into aligned concatenated arrays, and that in early CRs myosin II formed discrete clusters that transformed into the linearized structure over time. The present study extends our previous work by addressing the hypothesis that these myosin II clusters also contain the crucial scaffolding proteins anillin and septin, known to help link actin, myosin II, RhoA, and the membrane during cytokinesis. Super-resolution imaging of cortices from dividing embryos indicates that within each cluster, anillin and septin2 occupy a centralized position relative to the myosin II mini-filaments. As CR formation progresses, the myosin II, septin and anillin containing clusters enlarge and coalesce into patchy and faintly linear patterns. Our super-resolution images provide the initial visualization of anillin and septin nanostructure within an animal cell CR, including evidence of a septin filament-like network. Furthermore, Latrunculin-treated embryos indicated that the localization of septin or anillin to the myosin II clusters in the early CR was not dependent on actin filaments. These results highlight the structural progression of the CR in sea urchin embryos from an array of clusters to a linearized purse string, the association of anillin and septin with this process, and provide the visualization of an apparent septin filament network with the CR structure of an animal cell.
Collapse
Affiliation(s)
- Chelsea Garno
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
| | - Zoe H. Irons
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
| | - Courtney M. Gamache
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
| | - Quenelle McKim
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
| | - Gabriela Reyes
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
| | - Xufeng Wu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Charles B. Shuster
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
| | - John H. Henson
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
15
|
Truong Quang BA, Peters R, Cassani DAD, Chugh P, Clark AG, Agnew M, Charras G, Paluch EK. Extent of myosin penetration within the actin cortex regulates cell surface mechanics. Nat Commun 2021; 12:6511. [PMID: 34764258 PMCID: PMC8586027 DOI: 10.1038/s41467-021-26611-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 10/04/2021] [Indexed: 12/11/2022] Open
Abstract
In animal cells, shape is mostly determined by the actomyosin cortex, a thin cytoskeletal network underlying the plasma membrane. Myosin motors generate tension in the cortex, and tension gradients result in cellular deformations. As such, many cell morphogenesis studies have focused on the mechanisms controlling myosin activity and recruitment to the cortex. Here, we demonstrate using super-resolution microscopy that myosin does not always overlap with actin at the cortex, but remains restricted towards the cytoplasm in cells with low cortex tension. We propose that this restricted penetration results from steric hindrance, as myosin minifilaments are considerably larger than the cortical actin meshsize. We identify myosin activity and actin network architecture as key regulators of myosin penetration into the cortex, and show that increasing myosin penetration increases cortical tension. Our study reveals that the spatial coordination of myosin and actin at the cortex regulates cell surface mechanics, and unveils an important mechanism whereby myosin size controls its action by limiting minifilament penetration into the cortical actin network. More generally, our findings suggest that protein size could regulate function in dense cytoskeletal structures. Cellular deformations are largely driven by contractile forces generated by myosin motors in the submembraneous actin cortex. Here we show that these forces are controlled not simply by cortical myosin levels, but rather by myosins spatial arrangement, specifically the extent of their overlap with cortical actin.
Collapse
Affiliation(s)
- Binh An Truong Quang
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Ruby Peters
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, UK
| | - Davide A D Cassani
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Priyamvada Chugh
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Andrew G Clark
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK.,University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569, Stuttgart, Germany
| | - Meghan Agnew
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK.,Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Ewa K Paluch
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK. .,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, UK.
| |
Collapse
|
16
|
Pan MH, Wan X, Wang HH, Pan ZN, Zhang Y, Sun SC. FMNL3 regulates FASCIN for actin-mediated spindle migration and cytokinesis in mouse oocytes†. Biol Reprod 2021; 102:1203-1212. [PMID: 32167535 DOI: 10.1093/biolre/ioaa033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/23/2020] [Accepted: 03/12/2020] [Indexed: 11/14/2022] Open
Abstract
Formin-like 3 (FMNL3) is a member of the formin-likes (FMNLs), which belong to the formin family. As an F-actin nucleator, FMNL3 is essential for several cellular functions, such as polarity control, invasion, and migration. However, the roles of FMNL3 during oocytes meiosis remain unclear. In this study, we investigated the functions of FMNL3 during mouse oocyte maturation. Our results showed that FMNL3 mainly concentrated in the oocyte cortex and spindle periphery. Depleting FMNL3 led to the failure of polar body extrusion, and we also found large polar bodies in the FMNL3-deleted oocytes, indicating the occurrence of symmetric meiotic division. There was no effect of FMNL3 on spindle organization; however, we observed spindle migration defects at late metaphase I, which might be due to the decreased cytoplasmic actin. Microinjecting Fmnl3-EGFP mRNA into Fmnl3-depleted oocytes significantly rescued these defects. In addition, the results of co-immunoprecipitation and the perturbation of protein expression experiments suggested that FMNL3 interacted with the actin-binding protein FASCIN for the regulation of actin filaments in oocytes. Thus, our results provide the evidence that FMNL3 regulates FASCIN for actin-mediated spindle migration and cytokinesis during mouse oocyte meiosis.
Collapse
Affiliation(s)
- Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| | - Hong-Hui Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| | - Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, China
| |
Collapse
|
17
|
Gibieža P, Petrikaitė V. The regulation of actin dynamics during cell division and malignancy. Am J Cancer Res 2021; 11:4050-4069. [PMID: 34659876 PMCID: PMC8493394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023] Open
Abstract
Actin is the most abundant protein in almost all the eukaryotic cells. Actin amino acid sequences are highly conserved and have not changed a lot during the progress of evolution, varying by no more than 20% in the completely different species, such as humans and algae. The network of actin filaments plays a crucial role in regulating cells' cytoskeleton that needs to undergo dynamic tuning and structural changes in order for various functional processes, such as cell motility, migration, adhesion, polarity establishment, cell growth and cell division, to take place in live cells. Owing to its fundamental role in the cell, actin is a prominent regulator of cell division, a process, whose success directly depends on morphological changes of actin cytoskeleton and correct segregation of duplicated chromosomes. Disorganization of actin framework during the last stage of cell division, known as cytokinesis, can lead to multinucleation and formation of polyploidy in post-mitotic cells, eventually developing into cancer. In this review, we will cover the principles of actin regulation during cell division and discuss how the control of actin dynamics is altered during the state of malignancy.
Collapse
Affiliation(s)
- Paulius Gibieža
- Laboratory of Drug Targets Histopathology, Institute of Cardiology, Lithuanian University of Health Sciences Kaunas, LT-50162, Lithuania
| | - Vilma Petrikaitė
- Laboratory of Drug Targets Histopathology, Institute of Cardiology, Lithuanian University of Health Sciences Kaunas, LT-50162, Lithuania
| |
Collapse
|
18
|
Li Y, Munro E. Filament-guided filament assembly provides structural memory of filament alignment during cytokinesis. Dev Cell 2021; 56:2486-2500.e6. [PMID: 34480876 DOI: 10.1016/j.devcel.2021.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/30/2021] [Accepted: 08/13/2021] [Indexed: 10/24/2022]
Abstract
During cytokinesis, animal cells rapidly remodel the equatorial cortex to build an aligned array of actin filaments called the contractile ring. Local reorientation of filaments by active equatorial compression is thought to underlie the emergence of filament alignment during ring assembly. Here, combining single molecule analysis and modeling in one-cell C. elegans embryos, we show that filaments turnover is far too fast for reorientation of individual filaments by equatorial compression to explain the observed alignment, even if favorably oriented filaments are selectively stabilized. By tracking single formin/CYK-1::GFP particles to monitor local filament assembly, we identify a mechanism that we call filament-guided filament assembly (FGFA), in which existing filaments serve as templates to orient the growth of new filaments. FGFA sharply increases the effective lifetime of filament orientation, providing structural memory that allows cells to build highly aligned filament arrays in response to equatorial compression, despite rapid turnover of individual filaments.
Collapse
Affiliation(s)
- Younan Li
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Edwin Munro
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
| |
Collapse
|
19
|
Sharma M, Jiang T, Jiang ZC, Moguel-Lehmer CE, Harris TJ. Emergence of a smooth interface from growth of a dendritic network against a mechanosensitive contractile material. eLife 2021; 10:66929. [PMID: 34423780 PMCID: PMC8410080 DOI: 10.7554/elife.66929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Structures and machines require smoothening of raw materials. Self-organized smoothening guides cell and tissue morphogenesis and is relevant to advanced manufacturing. Across the syncytial Drosophila embryo surface, smooth interfaces form between expanding Arp2/3-based actin caps and surrounding actomyosin networks, demarcating the circumferences of nascent dome-like compartments used for pseudocleavage. We found that forming a smooth and circular boundary of the surrounding actomyosin domain requires Arp2/3 in vivo. To dissect the physical basis of this requirement, we reconstituted the interacting networks using node-based models. In simulations of actomyosin networks with local clearances in place of Arp2/3 domains, rough boundaries persisted when myosin contractility was low. With addition of expanding Arp2/3 network domains, myosin domain boundaries failed to smoothen, but accumulated myosin nodes and tension. After incorporating actomyosin mechanosensitivity, Arp2/3 network growth locally induced a surrounding contractile actomyosin ring that smoothened the interface between the cytoskeletal domains, an effect also evident in vivo. In this way, a smooth structure can emerge from the lateral interaction of irregular active materials.
Collapse
Affiliation(s)
- Medha Sharma
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Tao Jiang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Zi Chen Jiang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | | | - Tony Jc Harris
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| |
Collapse
|
20
|
Evaluation of the In Vitro Biocompatibility of PEDOT:Nafion Coatings. NANOMATERIALS 2021; 11:nano11082022. [PMID: 34443853 PMCID: PMC8398002 DOI: 10.3390/nano11082022] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/03/2021] [Accepted: 08/06/2021] [Indexed: 11/16/2022]
Abstract
Poly(3,4-ethylenedioxythiophene)-Nafion (PEDOT:Nafion) is emerging as a promising alternative to PEDOT-polystyrene sulfonate (PEDOT:PSS) in organic bioelectronics. However, the biocompatibility of PEDOT:Nafion has not been investigated to date, limiting its deployment toward in vivo applications such as neural recording and stimulation. In the present study, the in vitro cytotoxicity of PEDOT:Nafion coatings, obtained by a water-based PEDOT:Nafion formulation, was evaluated using a primary cell culture of rat fibroblasts. The surface of PEDOT:Nafion coating was characterized by Atomic Force Microscopy (AFM) and water contact angle measurements. Fibroblasts adhesion and morphology was investigated by scanning electron microscopy (SEM) and AFM measurements. Cell proliferation was assessed by fluorescence microscopy, while cell viability was quantified by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), lactate dehydrogenase (LDH) and neutral red assays. The results showed that PEDOT:Nafion coatings obtained by the water dispersion were not cytotoxic, making the latter a reliable alternative to PEDOT:PSS dispersion, especially in terms of chronic in vivo applications.
Collapse
|
21
|
Henson JH, Samasa B, Shuster CB, Wikramanayake AH. The nanoscale organization of the Wnt signaling integrator Dishevelled in the vegetal cortex domain of an egg and early embryo. PLoS One 2021; 16:e0248197. [PMID: 34038442 PMCID: PMC8153439 DOI: 10.1371/journal.pone.0248197] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/11/2021] [Indexed: 01/03/2023] Open
Abstract
Canonical Wnt/β-catenin (cWnt) signaling is a crucial regulator of development and Dishevelled (Dsh/Dvl) functions as an integral part of this pathway by linking Wnt binding to the Frizzled:LRP5/6 receptor complex with β-catenin-stimulated gene expression. In many cell types Dsh has been localized to ill-defined cytoplasmic puncta, however in sea urchin eggs and embryos confocal fluorescence microscopy has shown that Dsh is localized to puncta present in a novel and development-essential vegetal cortex domain (VCD). In the present study, we used super-resolution light microscopy and platinum replica transmission electron microscopy (TEM) to provide the first views of the ultrastructural organization of Dsh within the sea urchin VCD. 3D structured illumination microscopy (SIM) imaging of isolated egg cortices demonstrated the graded distribution of Dsh in the VCD, whereas higher resolution stimulated emission depletion (STED) imaging revealed that some individual Dsh puncta consisted of more than one fluorescent source. Platinum replica immuno-TEM localization showed that Dsh puncta on the cytoplasmic face of the plasma membrane consisted of aggregates of pedestal-like structures each individually labeled with the C-terminus specific Dsh antibody. These aggregates were resistant to detergent extraction and treatment with drugs that disrupt actin filaments or inhibit myosin II contraction, and coexisted with the first cleavage actomyosin contractile ring. These results confirm and extend previous studies and reveal, for the first time in any cell type, the nanoscale organization of plasma membrane tethered Dsh. Our current working hypothesis is that these Dsh pedestals represent a prepositioned scaffold organization that is important for the localized activation of the cWnt pathway at the sea urchin vegetal pole. These observations in sea urchins may also be relevant to the submembranous Dsh puncta present in other eggs and embryos.
Collapse
Affiliation(s)
- John H. Henson
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- * E-mail:
| | - Bakary Samasa
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, United States of America
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
| | - Charles B. Shuster
- Friday Harbor Laboratories, University of Washington, Friday Harbor, Washington, United States of America
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
| | | |
Collapse
|
22
|
Molecular basis of functional exchangeability between ezrin and other actin-membrane associated proteins during cytokinesis. Exp Cell Res 2021; 403:112600. [PMID: 33862101 DOI: 10.1016/j.yexcr.2021.112600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 01/09/2023]
Abstract
The mechanism that mediates the interaction between the contractile ring and the plasma membrane during cytokinesis remains elusive. We previously found that ERM (Ezrin/Radixin/Moesin) proteins, which usually mediate cellular pole contraction, become over-accumulated at the cell equator and support furrow ingression upon the loss of other actin-membrane associated proteins, anillin and supervillin. In this study, we addressed the molecular basis of the exchangeability between ezrin and other actin-membrane associated proteins in mediating cortical contraction during cytokinesis. We found that depletion of anillin and supervillin caused over-accumulation of the membrane-associated FERM domain and actin-binding C-terminal domain (C-term) of ezrin at the cleavage furrow, respectively. This finding suggests that ezrin differentially shares its binding sites with these proteins on the actin cytoskeleton or inner membrane surface. Using chimeric mutants, we found that ezrin C-term, but not the FERM domain, can substitute for the corresponding anillin domains in cytokinesis and cell proliferation. On the other hand, either the membrane-associated or the actin/myosin-binding domains of anillin could not substitute for the corresponding ezrin domains in controlling cortical blebbing at the cell poles. Our results highlight specific designs of actin- or membrane-associated moieties of different actin-membrane associated proteins with limited exchangeability, which enables them to support diverse cortical activities on the shared actin-membrane interface during cytokinesis.
Collapse
|
23
|
Lehtimäki JI, Rajakylä EK, Tojkander S, Lappalainen P. Generation of stress fibers through myosin-driven reorganization of the actin cortex. eLife 2021; 10:60710. [PMID: 33506761 PMCID: PMC7877910 DOI: 10.7554/elife.60710] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/27/2021] [Indexed: 12/26/2022] Open
Abstract
Contractile actomyosin bundles, stress fibers, govern key cellular processes including migration, adhesion, and mechanosensing. Stress fibers are thus critical for developmental morphogenesis. The most prominent actomyosin bundles, ventral stress fibers, are generated through coalescence of pre-existing stress fiber precursors. However, whether stress fibers can assemble through other mechanisms has remained elusive. We report that stress fibers can also form without requirement of pre-existing actomyosin bundles. These structures, which we named cortical stress fibers, are embedded in the cell cortex and assemble preferentially underneath the nucleus. In this process, non-muscle myosin II pulses orchestrate the reorganization of cortical actin meshwork into regular bundles, which promote reinforcement of nascent focal adhesions, and subsequent stabilization of the cortical stress fibers. These results identify a new mechanism by which stress fibers can be generated de novo from the actin cortex and establish role for stochastic myosin pulses in the assembly of functional actomyosin bundles.
Collapse
Affiliation(s)
- Jaakko I Lehtimäki
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Eeva Kaisa Rajakylä
- Section of Pathology, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Sari Tojkander
- Section of Pathology, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
24
|
Ke W, Wang B, Hua W, Song Y, Lu S, Luo R, Li G, Wang K, Liao Z, Xiang Q, Li S, Wu X, Zhang Y, Yang C. The distinct roles of myosin IIA and IIB under compression stress in nucleus pulposus cells. Cell Prolif 2021; 54:e12987. [PMID: 33415745 PMCID: PMC7848961 DOI: 10.1111/cpr.12987] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/08/2020] [Accepted: 12/23/2020] [Indexed: 12/24/2022] Open
Abstract
Objectives Inappropriate or excessive compression applied to intervertebral disc (IVD) contributes substantially to IVD degeneration. The actomyosin system plays a leading role in responding to mechanical stimuli. In the present study, we investigated the roles of myosin II isoforms in the compression stress‐induced senescence of nucleus pulposus (NP) cells. Material and methods Nucleus pulposus cells were exposed to 1.0 MPa compression for 0, 12, 24 or 36 hours. Immunofluorescence and co‐immunoprecipitation analysis were used to measure the interaction of myosin IIA and IIB with actin. Western blot analysis and immunofluorescence staining were used to detect nuclear expression and nuclear localization of MRTF‐A. In addition, the expression levels of p‐RhoA/RhoA, ROCK1/2 and p‐MLC/MLC were measured in human NP cells under compression stress and in degenerative IVD tissues. Results Compression stress increased the interaction of myosin IIA and actin, while the interaction of myosin IIB and actin was reduced. The actomyosin cytoskeleton remodelling was involved in the compression stress‐induced fibrotic phenotype mediated by MRTF‐A nuclear translocation and inhibition of proliferation in NP cells. Furthermore, RhoA/ROCK1 pathway activation mediated compression stress‐induced human NP cells senescence by regulating the interaction of myosin IIA and IIB with actin. Conclusions We for the first time investigated the regulation of actomyosin cytoskeleton in human NP cells under compression stress. It provided new insights into the development of therapy for effectively inhibiting IVD degeneration.
Collapse
Affiliation(s)
- Wencan Ke
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bingjin Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wenbin Hua
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Song
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Saideng Lu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rongjin Luo
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gaocai Li
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kun Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiwei Liao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qian Xiang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shuai Li
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xinghuo Wu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yukun Zhang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cao Yang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
25
|
Magliozzi JO, Moseley JB. Connecting cell polarity signals to the cytokinetic machinery in yeast and metazoan cells. Cell Cycle 2021; 20:1-10. [PMID: 33397181 DOI: 10.1080/15384101.2020.1864941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Polarized growth and cytokinesis are two fundamental cellular processes that exist in virtually all cell types. Mechanisms for asymmetric distribution of materials allow for cells to grow in a polarized manner. This gives rise to a variety of cell shapes seen throughout all cell types. Following polarized growth during interphase, dividing cells assemble a cytokinetic ring containing the protein machinery to constrict and separate daughter cells. Here, we discuss how cell polarity signaling pathways act on cytokinesis, with a focus on direct regulation of the contractile actomyosin ring (CAR). Recent studies have exploited phosphoproteomics to identify new connections between cell polarity kinases and CAR proteins. Existing evidence suggests that some polarity kinases guide the local organization of CAR proteins and structures while also contributing to global organization of the division plane within a cell. We provide several examples of this regulation from budding yeast, fission yeast, and metazoan cells. In some cases, kinase-substrate connections point to conserved processes in these different organisms. We point to several examples where future work can indicate the degree of conservation and divergence in the cell division process of these different organisms.
Collapse
Affiliation(s)
- Joseph O Magliozzi
- Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth , Hanover, New Hampshire, USA
| | - James B Moseley
- Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth , Hanover, New Hampshire, USA
| |
Collapse
|
26
|
Wang K, Okada H, Bi E. Comparative Analysis of the Roles of Non-muscle Myosin-IIs in Cytokinesis in Budding Yeast, Fission Yeast, and Mammalian Cells. Front Cell Dev Biol 2020; 8:593400. [PMID: 33330476 PMCID: PMC7710916 DOI: 10.3389/fcell.2020.593400] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/30/2020] [Indexed: 12/31/2022] Open
Abstract
The contractile ring, which plays critical roles in cytokinesis in fungal and animal cells, has fascinated biologists for decades. However, the basic question of how the non-muscle myosin-II and actin filaments are assembled into a ring structure to drive cytokinesis remains poorly understood. It is even more mysterious why and how the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and humans construct the ring structure with one, two, and three myosin-II isoforms, respectively. Here, we provide a comparative analysis of the roles of the non-muscle myosin-IIs in cytokinesis in these three model systems, with the goal of defining the common and unique features and highlighting the major questions regarding this family of proteins.
Collapse
Affiliation(s)
- Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
27
|
Pal D, Ellis A, Sepúlveda-Ramírez SP, Salgado T, Terrazas I, Reyes G, De La Rosa R, Henson JH, Shuster CB. Rac and Arp2/3-Nucleated Actin Networks Antagonize Rho During Mitotic and Meiotic Cleavages. Front Cell Dev Biol 2020; 8:591141. [PMID: 33282870 PMCID: PMC7705106 DOI: 10.3389/fcell.2020.591141] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/20/2020] [Indexed: 12/01/2022] Open
Abstract
In motile cells, the activities of the different Rho family GTPases are spatially segregated within the cell, and during cytokinesis there is evidence that this may also be the case. But while Rho’s role as the central organizer for contractile ring assembly is well established, the role of Rac and the branched actin networks it promotes is less well understood. To characterize the contributions of these proteins during cytokinesis, we manipulated Rac and Arp2/3 activity during mitosis and meiosis in sea urchin embryos and sea star oocytes. While neither Rac nor Arp2/3 were essential for early embryonic divisions, loss of either Rac or Arp2/3 activity resulted in polar body defects. Expression of activated Rac resulted in cytokinesis failure as early as the first division, and in oocytes, activated Rac suppressed both the Rho wave that traverses the oocyte prior to polar body extrusion as well as polar body formation itself. However, the inhibitory effect of Rac on cytokinesis, polar body formation and the Rho wave could be suppressed by effector-binding mutations or direct inhibition of Arp2/3. Together, these results suggest that Rac- and Arp2/3 mediated actin networks may directly antagonize Rho signaling, thus providing a potential mechanism to explain why Arp2/3-nucleated branched actin networks must be suppressed at the cell equator for successful cytokinesis.
Collapse
Affiliation(s)
- Debadrita Pal
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Andrea Ellis
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | | | - Torey Salgado
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Isabella Terrazas
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Gabriela Reyes
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Richard De La Rosa
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - John H Henson
- Department of Biology, Dickinson College, Carlisle, PA, United States
| | - Charles B Shuster
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| |
Collapse
|
28
|
Kelkar M, Bohec P, Charras G. Mechanics of the cellular actin cortex: From signalling to shape change. Curr Opin Cell Biol 2020; 66:69-78. [DOI: 10.1016/j.ceb.2020.05.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/30/2020] [Accepted: 05/08/2020] [Indexed: 01/17/2023]
|
29
|
Leite J, Chan FY, Osório DS, Saramago J, Sobral AF, Silva AM, Gassmann R, Carvalho AX. Equatorial Non-muscle Myosin II and Plastin Cooperate to Align and Compact F-actin Bundles in the Cytokinetic Ring. Front Cell Dev Biol 2020; 8:573393. [PMID: 33102479 PMCID: PMC7546906 DOI: 10.3389/fcell.2020.573393] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022] Open
Abstract
Cytokinesis is the last step of cell division that physically partitions the mother cell into two daughter cells. Cytokinesis requires the assembly and constriction of a contractile ring, a circumferential array of filamentous actin (F-actin), non-muscle myosin II motors (myosin), and actin-binding proteins that forms at the cell equator. Cytokinesis is accompanied by long-range cortical flows from regions of relaxation toward regions of compression. In the C. elegans one-cell embryo, it has been suggested that anterior-directed cortical flows are the main driver of contractile ring assembly. Here, we use embryos co-expressing motor-dead and wild-type myosin to show that cortical flows can be severely reduced without major effects on contractile ring assembly and timely completion of cytokinesis. Fluorescence recovery after photobleaching in the ingressing furrow reveals that myosin recruitment kinetics are also unaffected by the absence of cortical flows. We find that myosin cooperates with the F-actin crosslinker plastin to align and compact F-actin bundles at the cell equator, and that this cross-talk is essential for cytokinesis. Our results thus argue against the idea that cortical flows are a major determinant of contractile ring assembly. Instead, we propose that contractile ring assembly requires localized concerted action of motor-competent myosin and plastin at the cell equator.
Collapse
Affiliation(s)
- Joana Leite
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Fung-Yi Chan
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Daniel S Osório
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Joana Saramago
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana F Sobral
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana M Silva
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Reto Gassmann
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana X Carvalho
- Cytoskeletal Dynamics Lab, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Cytoskeletal Dynamics Lab, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| |
Collapse
|
30
|
Mikhaylova M, Rentsch J, Ewers H. Actomyosin Contractility in the Generation and Plasticity of Axons and Dendritic Spines. Cells 2020; 9:cells9092006. [PMID: 32882840 PMCID: PMC7565476 DOI: 10.3390/cells9092006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/19/2020] [Accepted: 08/25/2020] [Indexed: 12/15/2022] Open
Abstract
Actin and non-muscle myosins have long been known to play important roles in growth cone steering and neurite outgrowth. More recently, novel functions for non-muscle myosin have been described in axons and dendritic spines. Consequently, possible roles of actomyosin contraction in organizing and maintaining structural properties of dendritic spines, the size and location of axon initial segment and axonal diameter are emerging research topics. In this review, we aim to summarize recent findings involving myosin localization and function in these compartments and to discuss possible roles for actomyosin in their function and the signaling pathways that control them.
Collapse
Affiliation(s)
- Marina Mikhaylova
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, 10115 Berlin, Germany
- DFG Emmy Noether Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Correspondence: (M.M.); (H.E.); Tel.: +49-4074-1055-815 (M.M.); +49-30-838-60644 (H.E.)
| | - Jakob Rentsch
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
| | - Helge Ewers
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
- Correspondence: (M.M.); (H.E.); Tel.: +49-4074-1055-815 (M.M.); +49-30-838-60644 (H.E.)
| |
Collapse
|
31
|
Bindl J, Molnar ES, Ecke M, Prassler J, Müller-Taubenberger A, Gerisch G. Unilateral Cleavage Furrows in Multinucleate Cells. Cells 2020; 9:E1493. [PMID: 32570994 PMCID: PMC7349700 DOI: 10.3390/cells9061493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/16/2022] Open
Abstract
Multinucleate cells can be produced in Dictyostelium by electric pulse-induced fusion. In these cells, unilateral cleavage furrows are formed at spaces between areas that are controlled by aster microtubules. A peculiarity of unilateral cleavage furrows is their propensity to join laterally with other furrows into rings to form constrictions. This means cytokinesis is biphasic in multinucleate cells, the final abscission of daughter cells being independent of the initial direction of furrow progression. Myosin-II and the actin filament cross-linking protein cortexillin accumulate in unilateral furrows, as they do in the normal cleavage furrows of mononucleate cells. In a myosin-II-null background, multinucleate or mononucleate cells were produced by cultivation either in suspension or on an adhesive substrate. Myosin-II is not essential for cytokinesis either in mononucleate or in multinucleate cells but stabilizes and confines the position of the cleavage furrows. In fused wild-type cells, unilateral furrows ingress with an average velocity of 1.7 µm × min-1, with no appreciable decrease of velocity in the course of ingression. In multinucleate myosin-II-null cells, some of the furrows stop growing, thus leaving space for the extensive broadening of the few remaining furrows.
Collapse
Affiliation(s)
- Julia Bindl
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany; (J.B.); (E.S.M.); (M.E.); (J.P.)
| | - Eszter Sarolta Molnar
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany; (J.B.); (E.S.M.); (M.E.); (J.P.)
| | - Mary Ecke
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany; (J.B.); (E.S.M.); (M.E.); (J.P.)
| | - Jana Prassler
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany; (J.B.); (E.S.M.); (M.E.); (J.P.)
| | - Annette Müller-Taubenberger
- LMU Munich, Department of Cell Biology (Anatomy III), Biomedical Center, D-82152 Planegg-Martinsried, Germany;
| | - Günther Gerisch
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany; (J.B.); (E.S.M.); (M.E.); (J.P.)
| |
Collapse
|
32
|
Wang T, Li W, Martin S, Papadopulos A, Joensuu M, Liu C, Jiang A, Shamsollahi G, Amor R, Lanoue V, Padmanabhan P, Meunier FA. Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability. J Cell Biol 2020; 219:e201902001. [PMID: 32182623 PMCID: PMC7199852 DOI: 10.1083/jcb.201902001] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 09/17/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023] Open
Abstract
Most mammalian neurons have a narrow axon, which constrains the passage of large cargoes such as autophagosomes that can be larger than the axon diameter. Radial axonal expansion must therefore occur to ensure efficient axonal trafficking. In this study, we reveal that the speed of various large cargoes undergoing axonal transport is significantly slower than that of small ones and that the transit of diverse-sized cargoes causes an acute, albeit transient, axonal radial expansion, which is immediately restored by constitutive axonal contractility. Using live super-resolution microscopy, we demonstrate that actomyosin-II controls axonal radial contractility and local expansion, and that NM-II filaments associate with periodic F-actin rings via their head domains. Pharmacological inhibition of NM-II activity significantly increases axon diameter by detaching the NM-II from F-actin and impacts the trafficking speed, directionality, and overall efficiency of long-range retrograde trafficking. Consequently, prolonged NM-II inactivation leads to disruption of periodic actin rings and formation of focal axonal swellings, a hallmark of axonal degeneration.
Collapse
Affiliation(s)
- Tong Wang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Wei Li
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Sally Martin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Chunxia Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Anmin Jiang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Golnoosh Shamsollahi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Rumelo Amor
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Pranesh Padmanabhan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Frédéric A. Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| |
Collapse
|
33
|
Yagisawa F, Fujiwara T, Takemura T, Kobayashi Y, Sumiya N, Miyagishima SY, Nakamura S, Imoto Y, Misumi O, Tanaka K, Kuroiwa H, Kuroiwa T. ESCRT Machinery Mediates Cytokinetic Abscission in the Unicellular Red Alga Cyanidioschyzon merolae. Front Cell Dev Biol 2020; 8:169. [PMID: 32346536 PMCID: PMC7169423 DOI: 10.3389/fcell.2020.00169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/29/2020] [Indexed: 12/17/2022] Open
Abstract
In many eukaryotes, cytokinesis proceeds in two successive steps: first, ingression of the cleavage furrow and second, abscission of the intercellular bridge. In animal cells, the actomyosin contractile ring is involved in the first step, while the endosomal sorting complex required for transport (ESCRT), which participates in various membrane fusion/fission events, mediates the second step. Intriguingly, in archaea, ESCRT is involved in cytokinesis, raising the hypothesis that the function of ESCRT in eukaryotic cytokinesis descended from the archaeal ancestor. In eukaryotes other than in animals, the roles of ESCRT in cytokinesis are poorly understood. To explore the primordial core mechanisms for eukaryotic cytokinesis, we investigated ESCRT functions in the unicellular red alga Cyanidioschyzon merolae that diverged early in eukaryotic evolution. C. merolae provides an excellent experimental system. The cell has a simple organelle composition. The genome (16.5 Mb, 5335 genes) has been completely sequenced, transformation methods are established, and the cell cycle is synchronized by a light and dark cycle. Similar to animal and fungal cells, C. merolae cells divide by furrowing at the division site followed by abscission of the intercellular bridge. However, they lack an actomyosin contractile ring. The proteins that comprise ESCRT-I-IV, the four subcomplexes of ESCRT, are partially conserved in C. merolae. Immunofluorescence of native or tagged proteins localized the homologs of the five ESCRT-III components [charged multivesicular body protein (CHMP) 1, 2, and 4-6], apoptosis-linked gene-2-interacting protein X (ALIX), the ESCRT-III adapter, and the main ESCRT-IV player vacuolar protein sorting (VPS) 4, to the intercellular bridge. In addition, ALIX was enriched around the cleavage furrow early in cytokinesis. When the ESCRT function was perturbed by expressing dominant-negative VPS4, cells with an elongated intercellular bridge accumulated-a phenotype resulting from abscission failure. Our results show that ESCRT mediates cytokinetic abscission in C. merolae. The fact that ESCRT plays a role in cytokinesis in archaea, animals, and early diverged alga C. merolae supports the hypothesis that the function of ESCRT in cytokinesis descended from archaea to a common ancestor of eukaryotes.
Collapse
Affiliation(s)
- Fumi Yagisawa
- Center for Research Advancement and Collaboration, University of the Ryukyus, Okinawa, Japan
- Graduate School of Engineering and Science, University of the Ryukyus, Okinawa, Japan
| | - Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka, Japan
- JST-Mirai Program, Japan Science and Technology Agency, Saitama, Japan
- Department of Genetics, The Graduate University for Advanced Studies, Shizuoka, Japan
| | - Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- School of Life Sciences and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Nobuko Sumiya
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka, Japan
| | - Shin-ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka, Japan
- JST-Mirai Program, Japan Science and Technology Agency, Saitama, Japan
- Department of Genetics, The Graduate University for Advanced Studies, Shizuoka, Japan
| | - Soichi Nakamura
- Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Yuuta Imoto
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Osami Misumi
- Department of Biological Science and Chemistry, Faculty of Science, Yamaguchi University, Yamaguchi, Japan
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Haruko Kuroiwa
- Department of Chemical and Biological Science, Japan Women’s University, Tokyo, Japan
| | - Tsuneyoshi Kuroiwa
- Department of Chemical and Biological Science, Japan Women’s University, Tokyo, Japan
| |
Collapse
|
34
|
Cytokinesis in Eukaryotic Cells: The Furrow Complexity at a Glance. Cells 2020; 9:cells9020271. [PMID: 31979090 PMCID: PMC7072619 DOI: 10.3390/cells9020271] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/31/2022] Open
Abstract
The duplication cycle is the fascinating process that, starting from a cell, results in the formation of two daughter cells and it is essential for life. Cytokinesis is the final step of the cell cycle, it is a very complex phase, and is a concert of forces, remodeling, trafficking, and cell signaling. All of the steps of cell division must be properly coordinated with each other to faithfully segregate the genetic material and this task is fundamental for generating viable cells. Given the importance of this process, molecular pathways and proteins that are involved in cytokinesis are conserved from yeast to humans. In this review, we describe symmetric and asymmetric cell division in animal cell and in a model organism, budding yeast. In addition, we illustrate the surveillance mechanisms that ensure a proper cell division and discuss the connections with normal cell proliferation and organs development and with the occurrence of human diseases.
Collapse
|
35
|
Chan FY, Silva AM, Carvalho AX. Using the Four-Cell C. elegans Embryo to Study Contractile Ring Dynamics During Cytokinesis. Methods Mol Biol 2020; 2101:297-325. [PMID: 31879911 DOI: 10.1007/978-1-0716-0219-5_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cytokinesis is the process that completes cell division by partitioning the contents of the mother cell between the two daughter cells. It involves the highly regulated assembly and constriction of an actomyosin contractile ring, whose function is to pinch the mother cell in two. Research on the contractile ring has particularly focused on the signaling mechanisms that dictate when and where the ring is formed. In vivo studies of ring constriction are however scarce and its mechanistic understanding is therefore limited. Here we present several experimental approaches for monitoring ring constriction in vivo, using the four-cell C. elegans embryo as model. These approaches allow for the ring to be perturbed only after it forms and include the combination of live imaging with acute drug treatments, temperature-sensitive mutants and rapid temperature shifts, as well as laser microsurgery. In addition, we explain how to combine these with RNAi-mediated depletion of specific components of the cytokinetic machinery.
Collapse
Affiliation(s)
- Fung Yi Chan
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana Marta Silva
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana Xavier Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.
| |
Collapse
|
36
|
Pollard TD. Myosins in Cytokinesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1239:233-244. [DOI: 10.1007/978-3-030-38062-5_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
37
|
Meningitic Escherichia coli Induction of ANGPTL4 in Brain Microvascular Endothelial Cells Contributes to Blood-Brain Barrier Disruption via ARHGAP5/RhoA/MYL5 Signaling Cascade. Pathogens 2019; 8:pathogens8040254. [PMID: 31766605 PMCID: PMC6963727 DOI: 10.3390/pathogens8040254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 12/18/2022] Open
Abstract
Bacterial meningitis is currently recognized as one of the most important life-threatening infections of the central nervous system (CNS) with high morbidity and mortality, despite the advancements in antimicrobial treatment. The disruption of blood–brain barrier (BBB) induced by meningitis bacteria is crucial for the development of bacterial meningitis. However, the complete mechanisms involving in the BBB disruption remain to be elucidated. Here, we found meningitic Escherichia coli induction of angiopoietin-like 4 (ANGPTL4) in brain microvascular endothelial cells (BMECs) contributes to BBB disruption via ARHGAP5/RhoA/MYL5 signaling cascade, by the demonstration that ANGPTL4 was significantly upregulated in meningitis E. coli infection of BMECs as well as mice, and treatment of the recombinant ANGPTL4 protein led to an increased permeability of the BBB in vitro and in vivo. Moreover, we found that ANGPTL4 did not affect the expression of tight junction proteins involved in BBB disruption, but it increased the expression of MYL5, which was found to have a negative role on the regulation of barrier function during meningitic E. coli infection, through the activation of RhoA signaling pathway. To our knowledge, this is the first report demonstrating the disruption of BBB induced by ANGPTL4 through the ARHGAP5/RhoA/MYL5 pathway, which largely supports the involvement of ANGPTL4 during meningitic E. coli invasion and further expands the theoretical basis for the mechanism of bacterial meningitis.
Collapse
|
38
|
Osório DS, Chan FY, Saramago J, Leite J, Silva AM, Sobral AF, Gassmann R, Carvalho AX. Crosslinking activity of non-muscle myosin II is not sufficient for embryonic cytokinesis in C. elegans. Development 2019; 146:dev.179150. [PMID: 31582415 PMCID: PMC6857588 DOI: 10.1242/dev.179150] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/23/2019] [Indexed: 11/21/2022]
Abstract
Cytokinesis in animal cells requires the assembly and constriction of a contractile actomyosin ring. Non-muscle myosin II is essential for cytokinesis, but the role of its motor activity remains unclear. Here, we examine cytokinesis in C. elegans embryos expressing non-muscle myosin motor mutants generated by genome editing. Two non-muscle motor-dead myosins capable of binding F-actin do not support cytokinesis in the one-cell embryo, and two partially motor-impaired myosins delay cytokinesis and render rings more sensitive to reduced myosin levels. Further analysis of myosin mutants suggests that it is myosin motor activity, and not the ability of myosin to crosslink F-actin, that drives the alignment and compaction of F-actin bundles during contractile ring assembly, and that myosin motor activity sets the pace of contractile ring constriction. We conclude that myosin motor activity is required at all stages of cytokinesis. Finally, characterization of the corresponding motor mutations in C. elegans major muscle myosin shows that motor activity is required for muscle contraction but is dispensable for F-actin organization in adult muscles. This article has an associated ‘The people behind the papers’ interview. Highlighted Article: The motor activity of non-muscle myosin II is essential for cytokinesis and contributes to all stages of the process in C. elegans embryos.
Collapse
Affiliation(s)
- Daniel S Osório
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Fung-Yi Chan
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Saramago
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Leite
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana M Silva
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F Sobral
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Reto Gassmann
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana Xavier Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| |
Collapse
|
39
|
Dynamic polyhedral actomyosin lattices remodel micron-scale curved membranes during exocytosis in live mice. Nat Cell Biol 2019; 21:933-939. [PMID: 31358965 DOI: 10.1038/s41556-019-0365-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/25/2019] [Indexed: 01/10/2023]
Abstract
Actomyosin networks, the cell's major force production machineries, remodel cellular membranes during myriad dynamic processes1,2 by assembling into various architectures with distinct force generation properties3,4. While linear and branched actomyosin architectures are well characterized in cell-culture and cell-free systems3, it is not known how actin and myosin networks form and function to remodel membranes in complex three-dimensional mammalian tissues. Here, we use four-dimensional spinning-disc confocal microscopy with image deconvolution to acquire macromolecular-scale detail of dynamic actomyosin networks in exocrine glands of live mice. We address how actin and myosin organize around large membrane-bound secretory vesicles and generate the forces required to complete exocytosis5-7. We find that actin and non-muscle myosin II (NMII) assemble into previously undescribed polyhedral-like lattices around the vesicle membrane. The NMII lattice comprises bipolar minifilaments8-10 as well as non-canonical three-legged configurations. Using photobleaching and pharmacological perturbations in vivo, we show that actomyosin contractility and actin polymerization together push on the underlying vesicle membrane to overcome the energy barrier and complete exocytosis7. Our imaging approach thus unveils a force-generating actomyosin lattice that regulates secretion in the exocrine organs of live animals.
Collapse
|
40
|
Verma V, Mogilner A, Maresca TJ. Classical and Emerging Regulatory Mechanisms of Cytokinesis in Animal Cells. BIOLOGY 2019; 8:biology8030055. [PMID: 31357447 PMCID: PMC6784142 DOI: 10.3390/biology8030055] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/05/2019] [Accepted: 07/23/2019] [Indexed: 12/12/2022]
Abstract
The primary goal of cytokinesis is to produce two daughter cells, each having a full set of chromosomes. To achieve this, cells assemble a dynamic structure between segregated sister chromatids called the contractile ring, which is made up of filamentous actin, myosin-II, and other regulatory proteins. Constriction of the actomyosin ring generates a cleavage furrow that divides the cytoplasm to produce two daughter cells. Decades of research have identified key regulators and underlying molecular mechanisms; however, many fundamental questions remain unanswered and are still being actively investigated. This review summarizes the key findings, computational modeling, and recent advances in understanding of the molecular mechanisms that control the formation of the cleavage furrow and cytokinesis.
Collapse
Affiliation(s)
- Vikash Verma
- Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
- Department of Biology, New York University, New York, NY 10012, USA
| | - Thomas J Maresca
- Biology Department, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| |
Collapse
|
41
|
Wang S, O’Shaughnessy B. Anchoring of actin to the plasma membrane enables tension production in the fission yeast cytokinetic ring. Mol Biol Cell 2019; 30:2053-2064. [PMID: 31216223 PMCID: PMC6727776 DOI: 10.1091/mbc.e19-03-0173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/31/2019] [Accepted: 05/31/2019] [Indexed: 11/11/2022] Open
Abstract
The cytokinetic ring generates tensile force that drives cell division, but how tension emerges from the relatively disordered ring organization remains unclear. Long ago, a musclelike sliding filament mechanism was proposed, but evidence for sarcomeric order is lacking. Here we present quantitative evidence that in fission yeast, ring tension originates from barbed-end anchoring of actin filaments to the plasma membrane, providing resistance to myosin forces that enables filaments to develop tension. The role of anchoring was highlighted by experiments on isolated fission yeast rings, where sections of ring became unanchored from the membrane and shortened ∼30-fold faster than normal. The dramatically elevated constriction rates are unexplained. Here we present a molecularly explicit simulation of constricting partially anchored rings as studied in these experiments. Simulations accurately reproduced the experimental constriction rates and showed that following anchor release, a segment becomes tensionless and shortens via a novel noncontractile reeling-in mechanism at about the velocity of load-free myosin II. The ends are reeled in by barbed end-anchored actin filaments in adjacent segments. Other actin anchoring schemes failed to constrict rings. Our results quantitatively support a specific organization and anchoring scheme that generate tension in the cytokinetic ring.
Collapse
Affiliation(s)
- Shuyuan Wang
- Department of Physics, Columbia University, New York, NY 10027
| | - Ben O’Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027
| |
Collapse
|
42
|
Abstract
Division of amoebas, fungi, and animal cells into two daughter cells at the end of the cell cycle depends on a common set of ancient proteins, principally actin filaments and myosin-II motors. Anillin, formins, IQGAPs, and many other proteins regulate the assembly of the actin filaments into a contractile ring positioned between the daughter nuclei by different mechanisms in fungi and animal cells. Interactions of myosin-II with actin filaments produce force to assemble and then constrict the contractile ring to form a cleavage furrow. Contractile rings disassemble as they constrict. In some cases, knowledge about the numbers of participating proteins and their biochemical mechanisms has made it possible to formulate molecularly explicit mathematical models that reproduce the observed physical events during cytokinesis by computer simulations.
Collapse
Affiliation(s)
- Thomas D Pollard
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA;
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8103, USA
- Department of Cell Biology, Yale University, New Haven, Connecticut 06520-8103, USA
| | - Ben O'Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027, USA;
| |
Collapse
|
43
|
Abstract
Division of amoebas, fungi, and animal cells into two daughter cells at the end of the cell cycle depends on a common set of ancient proteins, principally actin filaments and myosin-II motors. Anillin, formins, IQGAPs, and many other proteins regulate the assembly of the actin filaments into a contractile ring positioned between the daughter nuclei by different mechanisms in fungi and animal cells. Interactions of myosin-II with actin filaments produce force to assemble and then constrict the contractile ring to form a cleavage furrow. Contractile rings disassemble as they constrict. In some cases, knowledge about the numbers of participating proteins and their biochemical mechanisms has made it possible to formulate molecularly explicit mathematical models that reproduce the observed physical events during cytokinesis by computer simulations.
Collapse
Affiliation(s)
- Thomas D Pollard
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA;
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8103, USA
- Department of Cell Biology, Yale University, New Haven, Connecticut 06520-8103, USA
| | - Ben O'Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027, USA;
| |
Collapse
|
44
|
Mangione MC, Gould KL. Molecular form and function of the cytokinetic ring. J Cell Sci 2019; 132:132/12/jcs226928. [PMID: 31209062 DOI: 10.1242/jcs.226928] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Animal cells, amoebas and yeast divide using a force-generating, actin- and myosin-based contractile ring or 'cytokinetic ring' (CR). Despite intensive research, questions remain about the spatial organization of CR components, the mechanism by which the CR generates force, and how other cellular processes are coordinated with the CR for successful membrane ingression and ultimate cell separation. This Review highlights new findings about the spatial relationship of the CR to the plasma membrane and the arrangement of molecules within the CR from studies using advanced microscopy techniques, as well as mechanistic information obtained from in vitro approaches. We also consider advances in understanding coordinated cellular processes that impact the architecture and function of the CR.
Collapse
Affiliation(s)
- MariaSanta C Mangione
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| |
Collapse
|
45
|
Network Contractility During Cytokinesis-from Molecular to Global Views. Biomolecules 2019; 9:biom9050194. [PMID: 31109067 PMCID: PMC6572417 DOI: 10.3390/biom9050194] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/30/2019] [Accepted: 04/30/2019] [Indexed: 12/28/2022] Open
Abstract
Cytokinesis is the last stage of cell division, which partitions the mother cell into two daughter cells. It requires the assembly and constriction of a contractile ring that consists of a filamentous contractile network of actin and myosin. Network contractility depends on network architecture, level of connectivity and myosin motor activity, but how exactly is the contractile ring network organized or interconnected and how much it depends on motor activity remains unclear. Moreover, the contractile ring is not an isolated entity; rather, it is integrated into the surrounding cortex. Therefore, the mechanical properties of the cell cortex and cortical behaviors are expected to impact contractile ring functioning. Due to the complexity of the process, experimental approaches have been coupled to theoretical modeling in order to advance its global understanding. While earlier coarse-grained descriptions attempted to provide an integrated view of the process, recent models have mostly focused on understanding the behavior of an isolated contractile ring. Here we provide an overview of the organization and dynamics of the actomyosin network during cytokinesis and discuss existing theoretical models in light of cortical behaviors and experimental evidence from several systems. Our view on what is missing in current models and should be tested in the future is provided.
Collapse
|
46
|
Abstract
The interactions of cytoskeletal actin filaments with myosin family motors are essential for the integrity and function of eukaryotic cells. They support a wide range of force-dependent functions. These include mechano-transduction, directed transcellular transport processes, barrier functions, cytokinesis, and cell migration. Despite the indispensable role of tropomyosins in the generation and maintenance of discrete actomyosin-based structures, the contribution of individual cytoskeletal tropomyosin isoforms to the structural and functional diversification of the actin cytoskeleton remains a work in progress. Here, we review processes that contribute to the dynamic sorting and targeted distribution of tropomyosin isoforms in the formation of discrete actomyosin-based structures in animal cells and their effects on actin-based motility and contractility.
Collapse
|
47
|
Echinoderm eggs as a model for discoveries in cell biology. Methods Cell Biol 2019. [PMID: 30948013 DOI: 10.1016/bs.mcb.2019.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
I happen to have been trained in cell and developmental biology in the early 1970s, which was near the beginning of the explosive growth of the field of cell biology. The American Society for Cell Biology had been founded in 1960 and so the field was in its early days. Cell biology research was dominated by the use of the electron microscope and by protein biochemistry. Molecular biology and the use of genetics were in their infancy. When we track the path of discoveries in cell biology contributed by research using echinoderm eggs, we follow the development of new technologies in genetics, molecular biology, biochemistry and biophysics, bioengineering, and imaging. The changes in approaches and methods have led to many key discoveries in cell biology through the use of sea urchin, sand dollar and sea star eggs. These include the discovery of cyclin, cytoplasmic dynein, rho activation for cytokinesis, new membrane addition as a late event in cytokinesis, multiple kinesins playing multiple roles, how flagella beat, the dynamics of microtubules in the mitotic apparatus, control over centrosomes and cell cycle checkpoints, the process of nuclear envelope breakdown for cell division, the discovery of 1-methyl adenine (hormones) as the trigger for meiotic maturation, Ca++ transients controlling cell activation and exocytosis among others. What I hope to provide in this perspective is to highlight some of those wonderful discoveries as my own career evolved to contribute to the field.
Collapse
|
48
|
Henson JH, Samasa B, Burg EC. High resolution imaging of the cortex isolated from sea urchin eggs and embryos. Methods Cell Biol 2019; 151:419-432. [PMID: 30948022 DOI: 10.1016/bs.mcb.2019.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The cellular cortex-consisting of the plasma membrane and the adjacent outer few microns of the cytoplasm-is a critically important, dynamic and complex region in the sea urchin egg and embryo. Some 40 years ago it was discovered that isolated cortices could be obtained from eggs adhered to glass coverslips and since that time this preparation has been used in a wide range of studies, including seminal research on fertilization, exocytosis, the cytoskeleton, and cytokinesis. In this chapter, we discuss methods for isolating cortices from eggs and embryos, including those undergoing cell division. We also provide protocols for analyzing cortical architecture and dynamics using specific localization methods combined with super-resolution Structured Illumination and Stimulated Emission Depletion light microscopy and platinum replica transmission electron microscopy.
Collapse
Affiliation(s)
- J H Henson
- Department of Biology, Dickinson College, Carlisle, PA, United States; Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, United States.
| | - Bakary Samasa
- Department of Biology, Dickinson College, Carlisle, PA, United States; Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, United States
| | - E C Burg
- Department of Biology, Dickinson College, Carlisle, PA, United States; Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, United States
| |
Collapse
|
49
|
Sepúlveda-Ramírez SP, Toledo-Jacobo L, Garno C, Pal D, Ross C, Ellis A, Shuster CB. Live-cell fluorescence imaging of echinoderm embryos. Methods Cell Biol 2019; 151:379-397. [PMID: 30948020 DOI: 10.1016/bs.mcb.2018.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The rapid development, simplicity and optical clarity of the sea urchin embryo make it an excellent model system for studying the dynamic events of early development. An ever-growing palette of fluorescent proteins and biosensors can now be applied to studying sea urchin development, and there are now a wide variety of imaging modes that can be employed to image sea urchin embryogenesis. However, when performing live-cell imaging, one must take into consideration the sensitivity of embryos (and fluorescent probes) to the intense light associated with confocal microscopes. Here, we discuss general considerations for keeping embryos viable on the microscope stage, as well as probes for imaging cellular membranes and the cytoskeleton. We compare the relative merits of different confocal microscopes for live imaging of embryos and describe the potential for live-cell super-resolution microscopy.
Collapse
Affiliation(s)
| | - Leslie Toledo-Jacobo
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Chelsea Garno
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Debadrita Pal
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Clara Ross
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Andrea Ellis
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Charles B Shuster
- Department of Biology, New Mexico State University, Las Cruces, NM, United States.
| |
Collapse
|
50
|
Abstract
Echinoderms are important research models for a wide range of biological questions. In particular, echinoderm embryos are exemplary models for dissecting the molecular and cellular processes that drive development and testing how these processes can be modified through evolution to produce the extensive morphological diversity observed in the phylum. Modern attempts to characterize these processes depend on some level of genomic analysis; from querying annotated gene sets to functional genomics experiments to identify candidate cis-regulatory sequences. Given how essential these data have become, it is important that researchers using available datasets or performing their own genome-scale experiments understand the nature and limitations of echinoderm genomic analyses. In this chapter we highlight the current state of echinoderm genomic data and provide methodological considerations for common approaches, including analysis of transcriptome and functional genomics datasets.
Collapse
|