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Schmitz-Elbers M, Lukinavičius G, Smit TH. Live Fluorescence Imaging of F-Actin Organization in Chick Whole Embryo Cultures Using SiR-Actin. Cells 2021; 10:1578. [PMID: 34206626 PMCID: PMC8303455 DOI: 10.3390/cells10071578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 11/24/2022] Open
Abstract
Morphogenesis is a continuous process of pattern formation so complex that it requires in vivo monitoring for better understanding. Changes in tissue shape are initiated at the cellular level, where dynamic intracellular F-actin networks determine the shape and motility of cells, influence differentiation and cytokinesis and mediate mechanical signaling. Here, we stain F-actin with the fluorogenic probe SiR-actin for live fluorescence imaging of whole chick embryos. We found that 50 nM SiR-actin in the culture medium is a safe and effective concentration for this purpose, as it provides high labeling density without inducing morphological malformations.
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Affiliation(s)
- Manuel Schmitz-Elbers
- Department of Orthopaedic Surgery, Amsterdam University Medical Centres, Amsterdam Movement Sciences, 1105 AZ Amsterdam, The Netherlands;
| | - Gražvydas Lukinavičius
- Chromatin Labeling and Imaging Group, Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
| | - Theodoor H. Smit
- Department of Orthopaedic Surgery, Amsterdam University Medical Centres, Amsterdam Movement Sciences, 1105 AZ Amsterdam, The Netherlands;
- Department of Medical Biology, Amsterdam University Medical Centres, 1105 AZ Amsterdam, The Netherlands
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Sun B, Qu R, Fan T, Yang Y, Jiang X, Khan AU, Zhou Z, Zhang J, Wei K, Ouyang J, Dai J. Actin polymerization state regulates osteogenic differentiation in human adipose-derived stem cells. Cell Mol Biol Lett 2021; 26:15. [PMID: 33858321 PMCID: PMC8048231 DOI: 10.1186/s11658-021-00259-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/03/2021] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Actin is an essential cellular protein that assembles into microfilaments and regulates numerous processes such as cell migration, maintenance of cell shape, and material transport. METHODS In this study, we explored the effect of actin polymerization state on the osteogenic differentiation of human adipose-derived stem cells (hASCs). The hASCs were treated for 7 days with different concentrations (0, 1, 5, 10, 20, and 50 nM) of jasplakinolide (JAS), a reagent that directly polymerizes F-actin. The effects of the actin polymerization state on cell proliferation, apoptosis, migration, and the maturity of focal adhesion-related proteins were assessed. In addition, western blotting and alizarin red staining assays were performed to assess osteogenic differentiation. RESULTS Cell proliferation and migration in the JAS (0, 1, 5, 10, and 20 nM) groups were higher than in the control group and the JAS (50 nM) group. The FAK, vinculin, paxillin, and talin protein expression levels were highest in the JAS (20 nM) group, while zyxin expression was highest in the JAS (50 nM) group. Western blotting showed that osteogenic differentiation in the JAS (0, 1, 5, 10, 20, and 50 nM) group was enhanced compared with that in the control group, and was strongest in the JAS (50 nM) group. CONCLUSIONS In summary, our data suggest that the actin polymerization state may promote the osteogenic differentiation of hASCs by regulating the protein expression of focal adhesion-associated proteins in a concentration-dependent manner. Our findings provide valuable information for exploring the mechanism of osteogenic differentiation in hASCs.
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Affiliation(s)
- Bing Sun
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Rongmei Qu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Tingyu Fan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Yuchao Yang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Xin Jiang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Asmat Ullah Khan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Zhitao Zhou
- Central Laboratory, Southern Medical University, Guangzhou, China
| | - Jingliao Zhang
- Department of Foot and Ankle Surgery, Henan Luoyang Orthopedic Hospital, Zhengzhou, China
| | - Kuanhai Wei
- Division of Orthopaedics and Traumatology, Department of Orthopaedics, Guangdong Provincial Key Laboratory of Bone and Cartilage Regeneration Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jun Ouyang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China.
| | - Jingxing Dai
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, China.
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Zhang X, Mariano CF, Ando Y, Shen K. Bioengineering tools for probing intracellular events in T lymphocytes. WIREs Mech Dis 2020; 13:e1510. [PMID: 33073545 DOI: 10.1002/wsbm.1510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 11/11/2022]
Abstract
T lymphocytes are the central coordinator and executor of many immune functions. The activation and function of T lymphocytes are mediated through the engagement of cell surface receptors and regulated by a myriad of intracellular signaling network. Bioengineering tools, including imaging modalities and fluorescent probes, have been developed and employed to elucidate the cellular events throughout the functional lifespan of T cells. A better understanding of these events can broaden our knowledge in the immune systems biology, as well as accelerate the development of effective diagnostics and immunotherapies. Here we review the commonly used and recently developed techniques and probes for monitoring T lymphocyte intracellular events, following the order of intracellular events in T cells from activation, signaling, metabolism to apoptosis. The techniques introduced here can be broadly applied to other immune cells and cell systems. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Immune System Diseases > Biomedical Engineering Infectious Diseases > Biomedical Engineering.
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Affiliation(s)
- Xinyuan Zhang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Chelsea F Mariano
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Yuta Ando
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Keyue Shen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA.,USC Stem Cell, University of Southern California, Los Angeles, California, USA
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4
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Temporary Membrane Permeabilization via the Pore-Forming Toxin Lysenin. Toxins (Basel) 2020; 12:toxins12050343. [PMID: 32456013 PMCID: PMC7290483 DOI: 10.3390/toxins12050343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/17/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Pore-forming toxins are alluring tools for delivering biologically-active, impermeable cargoes to intracellular environments by introducing large conductance pathways into cell membranes. However, the lack of regulation often leads to the dissipation of electrical and chemical gradients, which might significantly affect the viability of cells under scrutiny. To mitigate these problems, we explored the use of lysenin channels to reversibly control the barrier function of natural and artificial lipid membrane systems by controlling the lysenin's transport properties. We employed artificial membranes and electrophysiology measurements in order to identify the influence of labels and media on the lysenin channel's conductance. Two cell culture models: Jurkat cells in suspension and adherent ATDC5 cells were utilized to demonstrate that lysenin channels may provide temporary cytosol access to membrane non-permeant propidium iodide and phalloidin. Permeability and cell viability were assessed by fluorescence spectroscopy and microscopy. Membrane resealing by chitosan or specific media addition proved to be an effective way of maintaining cellular viability. In addition, we loaded non-permeant dyes into liposomes via lysenin channels by controlling their conducting state with multivalent metal cations. The improved control over membrane permeability might prove fruitful for a large variety of biological or biomedical applications that require only temporary, non-destructive access to the inner environment enclosed by natural and artificial membranes.
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Sarker SR, Takikawa M, Takeoka S. In Vitro Delivery of Cell Impermeable Phallotoxin Using Cationic Liposomes Composed of Lipids Bearing Lysine Headgroup. ACS APPLIED BIO MATERIALS 2020; 3:2048-2057. [DOI: 10.1021/acsabm.9b01167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Satya Ranjan Sarker
- Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University (TWIns), Shinjuku-ku, Tokyo 162-8480, Japan
- Department of Biotechnology and Genetic Engineering, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Masato Takikawa
- Department of Advanced Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University (TWIns), Shinjuku-ku, Tokyo 162-8480, Japan
| | - Shinji Takeoka
- Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University (TWIns), Shinjuku-ku, Tokyo 162-8480, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan
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Paez-Garcia A, Sparks JA, de Bang L, Blancaflor EB. Plant Actin Cytoskeleton: New Functions from Old Scaffold. PLANT CELL MONOGRAPHS 2018. [DOI: 10.1007/978-3-319-69944-8_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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The effect of CaCl 2 marination on the tenderizing pathway of goose meat during conditioning. Food Res Int 2017; 102:487-492. [PMID: 29195976 DOI: 10.1016/j.foodres.2017.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/05/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022]
Abstract
In order to figure out the effect of CaCl2 on the tenderizing pathway of goose meat, breast muscles of thirty-two Eastern Zhejiang White Geese were divided into three treatments: the control, 150 and 300mM CaCl2. Shear force, myofibrillar fraction index (MFI), actin filaments and F-actin, G-actin and tropomodulins (Tmods) levels were investigated during 168h. Results showed that 300mM treatment had lower shear force at 48, 96 and 168h and higher MFI at 24, 48, 96 and 168h than the control. The rate of actin filaments disruption, the decrease of F-actin, the degradation of Tmods, the increase of G-actin in 300mM treatment was faster than 150mM treatment; the rate in the control was the slowest among treatments. CaCl2 accelerated the transformation of F-actin into G-actin. We concluded that CaCl2 tenderized goose meat by depolymerizing actin filaments and cleaving Tmods.
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Liu J, Tie H, Chen H, Han R. The distribution of profilin in root-tip cells of wheat seedlings exposed to enhanced UV-B radiation. FRONTIERS IN LIFE SCIENCE 2015. [DOI: 10.1080/21553769.2015.1075434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Dyachok J, Sparks JA, Liao F, Wang YS, Blancaflor EB. Fluorescent protein-based reporters of the actin cytoskeleton in living plant cells: Fluorophore variant, actin binding domain, and promoter considerations. Cytoskeleton (Hoboken) 2014; 71:311-27. [DOI: 10.1002/cm.21174] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 02/27/2014] [Accepted: 03/19/2014] [Indexed: 12/28/2022]
Affiliation(s)
- Julia Dyachok
- Plant Biology Division; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - J. Alan Sparks
- Plant Biology Division; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - Fuqi Liao
- Department of Computing Services; The Samuel Roberts Noble Foundation; Ardmore Oklahoma
| | - Yuh-Shuh Wang
- Plant Signal Research Group; Institute of Technology, University of Tartu; Nooruse 1 Tartu 50411 Estonia
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10
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Cleary AL, Mathesius U. Rearrangements of F-actin during Stomatogenesis Visualised by Confocal Microscopy in Fixed and PermeabilisedTradescantiaLeaf Epidermis. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1996.tb00865.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Chen DH, Acharya BR, Liu W, Zhang W. Interaction between Calcium and Actin in Guard Cell and Pollen Signaling Networks. PLANTS (BASEL, SWITZERLAND) 2013; 2:615-34. [PMID: 27137395 PMCID: PMC4844389 DOI: 10.3390/plants2040615] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 12/17/2022]
Abstract
Calcium (Ca(2+)) plays important roles in plant growth, development, and signal transduction. It is a vital nutrient for plant physical design, such as cell wall and membrane, and also serves as a counter-cation for biochemical, inorganic, and organic anions, and more particularly, its concentration change in cytosol is a ubiquitous second messenger in plant physiological signaling in responses to developmental and environmental stimuli. Actin cytoskeleton is well known for its importance in cellular architecture maintenance and its significance in cytoplasmic streaming and cell division. In plant cell system, the actin dynamics is a process of polymerization and de-polymerization of globular actin and filamentous actin and that acts as an active regulator for calcium signaling by controlling calcium evoked physiological responses. The elucidation of the interaction between calcium and actin dynamics will be helpful for further investigation of plant cell signaling networks at molecular level. This review mainly focuses on the recent advances in understanding the interaction between the two aforementioned signaling components in two well-established model systems of plant, guard cell, and pollen.
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Affiliation(s)
- Dong-Hua Chen
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
| | - Biswa R Acharya
- Biology Department, Penn State University, University Park, PA 16802, USA.
| | - Wei Liu
- High-Tech Research Center, Shandong Academy of Agricultural Sciences, Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan 250100, Shandong, China.
| | - Wei Zhang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, College of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
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12
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Xu C, Liu Z, Zhang L, Zhao C, Yuan S, Zhang F. Organization of actin cytoskeleton during meiosis I in a wheat thermo-sensitive genic male sterile line. PROTOPLASMA 2013; 250:415-422. [PMID: 22350736 DOI: 10.1007/s00709-012-0386-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 01/30/2012] [Indexed: 05/31/2023]
Abstract
BS366 is a thermo-sensitive male sterile line of wheat (Triticum aestivum L.) for two-line hybrid breeding, which exhibits aberrant meiotic cytokinesis under low temperature. Through transcriptome analysis, a possible regulatory role for plant actin cytoskeleton was suggested. However, the organization of actin cytoskeleton in meiosis has been poorly understood so far. Here, fixed microsporocytes during meiosis were labeled with tetramethylrhodamine isothiocyanate-phalloidin and 4',6-diamidino-2-phenylindole. Quantities of fluorescent micrographs were captured using a confocal microscope, including the transient state from metaphase to telophase. We observed that actin filaments were abundant in typical kariokinetic spindle, central spindle (parallel microtubules or actin fibers between two separated chromosomes in anaphase), and phragmoplast. Interestingly, we identified the Chinese lantern-shaped actin phragmoplast in wheat meiosis for the first time. Under low temperature, phragmoplast actin filaments were chaotic and normal cell plate failed to form. These data provide new insights into the organization of actin filaments during male meiosis of plant and support a role of actin cytoskeleton in bringing about thermo-sensitive male sterility in wheat.
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Affiliation(s)
- Chenguang Xu
- Beijing Engineering and Technique Research Center for Hybrid Wheat, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
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13
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Liu P, Qi M, Xue X, Ren H. Dynamics and functions of the actin cytoskeleton during the plant cell cycle. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s11434-011-4801-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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14
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Du F, Ren H. Development and application of probes for labeling the actin cytoskeleton in living plant cells. PROTOPLASMA 2011; 248:239-50. [PMID: 20803158 DOI: 10.1007/s00709-010-0202-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 08/14/2010] [Indexed: 05/15/2023]
Abstract
The actin cytoskeleton is one of the most important components of eukaryotic cytoskeletons. It participates in numerous crucial procedures of cells and has been studied by using various methods. The development and application of appropriate probes for actin visualization is the first and foremost step for functional analysis of actin in vivo. Since the actin cytoskeleton is a highly dynamic and sensitive structure, methods previously used to visualize actin often harm cells and cannot reveal the native state of the actin cytoskeleton in living cells. The development of labeling technologies for living plant cells, especially the emergence and application of green fluorescent protein-tagged actin markers, has provided new insights into the structure and function of the actin cytoskeleton in vivo. There has been a number of probes for actin labeling in living plant cells though they each present different advantages and defects. In this review, we discuss and compare those widely used methods for actin visualization and analysis.
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Affiliation(s)
- Fei Du
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, Beijing, 100875, China
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Maiato H, Lince-Faria M. The perpetual movements of anaphase. Cell Mol Life Sci 2010; 67:2251-69. [PMID: 20306325 PMCID: PMC11115923 DOI: 10.1007/s00018-010-0327-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 02/17/2010] [Indexed: 12/29/2022]
Abstract
One of the most extraordinary events in the lifetime of a cell is the coordinated separation of sister chromatids during cell division. This is truly the essence of the entire mitotic process and the reason for the most profound morphological changes in cytoskeleton and nuclear organization that a cell may ever experience. It all occurs within a very short time window known as "anaphase", as if the cell had spent the rest of its existence getting ready for this moment in an ultimate act of survival. And there is a good reason for this: no space for mistakes. Problems in the distribution of chromosomes during cell division have been correlated with aneuploidy, a common feature observed in cancers and several birth defects, and the main cause of spontaneous abortion in humans. In this paper, we critically review the mechanisms of anaphase chromosome motion that resisted the scrutiny of more than 100 years of research, as part of a tribute to the pioneering work of Miguel Mota.
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Affiliation(s)
- Helder Maiato
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180, Porto, Portugal.
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Snyder JA, Ha Y, Olsofka C, Wahdan R. Both actin and myosin inhibitors affect spindle architecture in PtK1 cells: does an actomyosin system contribute to mitotic spindle forces by regulating attachment and movements of chromosomes in mammalian cells? PROTOPLASMA 2010; 240:57-68. [PMID: 20091066 DOI: 10.1007/s00709-009-0089-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 11/09/2009] [Indexed: 05/28/2023]
Abstract
Immunocytochemical techniques are used to analyze the effects of both an actin and myosin inhibitor on spindle architecture in PtK(1) cells to understand why both these inhibitors slow or block chromosome motion and detach chromosomes. Cytochalasin J, an actin inhibitor and a myosin inhibitor, 2, 3 butanedione 2-monoxime, have similar effects on changes in spindle organization. Using primary antibodies and stains, changes are studied in microtubule (MT), actin, myosin, and chromatin localization. Treatment of mitotic cells with both inhibitors results in detachment or misalignment of chromosomes from the spindle and a prominent buckling of MTs within the spindle, particularly evident in kinetochore fibers. Evidence is presented to suggest that an actomyosin system may help to regulate the initial and continued attachment of chromosomes to the mammalian spindle and could also influence spindle checkpoint(s).
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Affiliation(s)
- Judith A Snyder
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
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Thomas C, Tholl S, Moes D, Dieterle M, Papuga J, Moreau F, Steinmetz A. Actin bundling in plants. ACTA ACUST UNITED AC 2009; 66:940-57. [DOI: 10.1002/cm.20389] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Panteris E, Adamakis IDS, Tzioutziou NA. Abundance of actin filaments in the preprophase band and mitotic spindle of brick1 Zea mays mutant. PROTOPLASMA 2009; 236:103-106. [PMID: 19434475 DOI: 10.1007/s00709-009-0049-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Accepted: 05/04/2009] [Indexed: 05/27/2023]
Abstract
The preprophase band and mitotic spindle of dividing protodermal cells of wild-type Zea mays leaves include few actin filaments. Surprisingly, abundant actin filaments were observed in the above arrays, in dividing protodermal cells in the leaves of the brick1 mutant. The same abundance was observed in the spindle of Taxol-treated brick1 mitotic protodermal cells. Apart from the above difference, the relevant arrays displayed normal microtubule organization in both wild type and mutant cells, as far as can be discerned by immunofluorescence microscopy. Accordingly, the abundance of actin filaments in the preprophase band and spindle of brick1 mitotic cells seems not to influence the structure of the above arrays and might be a non-functional "side-effect" of defective F-actin organization in this mutant.
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Affiliation(s)
- Emmanuel Panteris
- Department of Botany, School of Biology, Aristotle University, Thessaloniki, 541 24, Macedonia, Greece.
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Sinclair A, Schenkel M, Mathur J. Signaling to the Actin Cytoskeleton During Cell Morphogenesis and Patterning. SIGNALING IN PLANTS 2009. [DOI: 10.1007/978-3-540-89228-1_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Higaki T, Kutsuna N, Sano T, Hasezawa S. Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis. BMC PLANT BIOLOGY 2008; 8:80. [PMID: 18637163 PMCID: PMC2490694 DOI: 10.1186/1471-2229-8-80] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2008] [Accepted: 07/17/2008] [Indexed: 05/19/2023]
Abstract
BACKGROUND Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs) and actin microfilaments (MFs). Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials. In contrast, disruption of MFs only delays cell plate expansion but does not completely inhibit cell plate formation. Despite such findings, the significance and molecular mechanisms of MTs and MFs remain largely unknown. RESULTS Time-sequential changes in MF-distribution were monitored by live imaging of tobacco BY-2 cells stably expressing the GFP-actin binding domain 2 (GFP-ABD2) fusion protein, which vitally co-stained with the endocytic tracer, FM4-64, that labels the cell plate. During cytokinesis, MFs accumulated near the newly-separated daughter nuclei towards the emerging cell plate, and subsequently approached the expanding cell plate edges. Treatment with an actin polymerization inhibitor caused a decrease in the cell plate expansion rate, which was quantified using time-lapse imaging and regression analysis. Our results demonstrated time-sequential changes in the contribution of MFs to cell plate expansion; MF-disruption caused about a 10% decrease in the cell plate expansion rate at the early phase of cytokinesis, but about 25% at the late phase. MF-disruption also caused malformation of the emerging cell plate at the early phase, indicative of MF involvement in early cell plate formation and expansion. The dynamic movement of endosomes around the cell plate was also inhibited by treatment with an actin polymerization inhibitor and a myosin ATPase inhibitor, respectively. Furthermore, time-lapse imaging of the endoplasmic reticulum (ER) revealed that MFs were involved in ER accumulation in the phragmoplast at the late phase. CONCLUSION By expression of GFP-ABD2 and vital staining with FM4-64, the dynamics of MFs and the cell plate could be followed throughout plant cytokinesis in living cells. Pharmacological treatment and live imaging analysis also allowed us to quantify MF contribution to cell plate expansion during cytokinesis. Our results suggest that MFs play significant roles in cell plate formation and expansion via regulation of endomembrane dynamics.
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Affiliation(s)
- Takumi Higaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
| | - Natsumaro Kutsuna
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
| | - Toshio Sano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
| | - Seiichiro Hasezawa
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha Kashiwa, Chiba 277-8562, Japan
- Institute for Bioinformatics Research and Development (BIRD), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-8666, Japan
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Panteris E. Cortical actin filaments at the division site of mitotic plant cells: a reconsideration of the 'actin-depleted zone'. THE NEW PHYTOLOGIST 2008; 179:334-341. [PMID: 19086286 DOI: 10.1111/j.1469-8137.2008.02474.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The preprophase bands of microtubules and F-actin are primary markers of the division site for most plant cells. After preprophase band breakdown, the division site has been considered to be 'negatively' memorized by the local absence of cortical actin filaments. However, there have been reports of cortical F-actin at the division site of mitotic plant cells, calling into question its distribution and possible role there. In this article, previous and recent data on this issue are reviewed. It is proposed that the division site of mitotic plant cells is not devoid of F-actin but is traversed by scarce cortical actin filaments. The description of the division site as an 'actin exclusion zone' might therefore be attributed to a failure to preserve and/or image the notoriously sensitive actin filaments. Accordingly, the 'actin-depleted zone' should be considered as a site with fewer actin filaments than the rest of the cortical cytoplasm. Taking into account recent molecular data on division site components, a possible role for the scarcity of cortical actin filaments in establishing a zone of minimum mobility is also proposed.
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Affiliation(s)
- Emmanuel Panteris
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, Thessaloniki GR-541 24, Macedonia, Greece
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22
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Lifeact: a versatile marker to visualize F-actin. Nat Methods 2008; 5:605-7. [PMID: 18536722 DOI: 10.1038/nmeth.1220] [Citation(s) in RCA: 1632] [Impact Index Per Article: 102.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 05/16/2008] [Indexed: 11/08/2022]
Abstract
Live imaging of the actin cytoskeleton is crucial for the study of many fundamental biological processes, but current approaches to visualize actin have several limitations. Here we describe Lifeact, a 17-amino-acid peptide, which stained filamentous actin (F-actin) structures in eukaryotic cells and tissues. Lifeact did not interfere with actin dynamics in vitro and in vivo and in its chemically modified peptide form allowed visualization of actin dynamics in nontransfectable cells.
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Fabian L, Forer A. Possible roles of actin and myosin during anaphase chromosome movements in locust spermatocytes. PROTOPLASMA 2007; 231:201-213. [PMID: 17922265 DOI: 10.1007/s00709-007-0262-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 12/20/2006] [Indexed: 05/25/2023]
Abstract
We tested whether the mechanisms of chromosome movement during anaphase in locust (Locusta migratoria L.) spermatocytes might be similar to those described for crane-fly spermatocytes. Actin and myosin have been implicated in anaphase chromosome movements in crane-fly spermatocytes, as indicated by the effects of inhibitors and by the localisations of actin and myosin in spindles. In this study, we tested whether locust spermatocyte spindles also utilise actin and myosin, and whether actin is involved in microtubule flux. Living locust spermatocytes were treated with inhibitors of actin (latrunculin B and cytochalasin D), myosin (BDM), or myosin phosphorylation (Y-27632 and ML-7). We added drugs (individually) during anaphase. Actin inhibitors alter anaphase: chromosomes either completely stop moving, slow, or sometimes accelerate. The myosin inhibitor, BDM, also alters anaphase: in most cases, the chromosomes drastically slow or stop. ML-7, an inhibitor of MLCK, causes chromosomes to stop, slow, or sometimes accelerate, similar to actin inhibitors. Y-27632, an inhibitor of Rho-kinase, drastically slows or stops anaphase chromosome movements. The effects of the drugs on anaphase movement are reversible: most of the half-bivalents resumed movement at normal speed after these drugs were washed out. Actin and myosin were present in the spindles in locations consistent with their possible involvement in force production. Microtubule flux along kinetochore fibres is an actin-dependent process, since LatB completely removes or drastically reduces the gap in microtubule acetylation at the kinetochore. These results suggest that actin and myosin are involved in anaphase chromosome movements in locust spermatocytes.
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Yoneda A, Kutsuna N, Higaki T, Oda Y, Sano T, Hasezawa S. Recent progress in living cell imaging of plant cytoskeleton and vacuole using fluorescent-protein transgenic lines and three-dimensional imaging. PROTOPLASMA 2007; 230:129-39. [PMID: 17458628 DOI: 10.1007/s00709-006-0237-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 03/17/2006] [Indexed: 05/15/2023]
Abstract
In higher-plant cells, microtubules, actin microfilaments, and vacuoles play important roles in a variety of cellular events, including cell division, morphogenesis, and cell differentiation. These intracellular structures undergo dynamic changes in their shapes and functions during cell division and differentiation, and to analyse these sequential structural changes, the vital labelling technique, using the green-fluorescent protein or other fluorescent proteins, has commonly been used to follow the localisation and translocation of specific proteins. To visualise microtubules, actin filaments, and vacuoles, several strategies are available for selecting the appropriate fluorescent-protein fusion partner: microtubule-binding proteins, tubulin, and plus-end-tracking proteins are most suitable for microtubule labelling; the actin binding domain of mouse talin and plant fimbrin for actin microfilament visualisation; and the tonoplast-intrinsic proteins and syntaxin-related proteins for vacuolar imaging. In addition, three-dimensional reconstruction methods are indispensable for localising the widely distributed organelles within the cell. The maximum intensity projection method is suitable for cytoskeletal structures, while contour-based surface modelling possesses many advantages for vacuolar membranes. In this article, we summarise the recent progress in living cell imaging of the plant cytoskeleton and vacuoles using various fusions with green-fluorescent proteins and three-dimensional imaging techniques.
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Affiliation(s)
- A Yoneda
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
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25
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Yu M, Yuan M, Ren H. Visualization of actin cytoskeletal dynamics during the cell cycle in tobacco (Nicotiana tabacum L. cv Bright Yellow) cells. Biol Cell 2006; 98:295-306. [PMID: 16359279 DOI: 10.1042/bc20050074] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION The actin cytoskeleton forms distinct actin arrays which fulfil their functions during cell cycle progression. Reorganization of the actin cytoskeleton occurs during transition from one actin array to another. Although actin arrays have been well described during cell cycle progression, the dynamic organization of the actin cytoskeleton during actin array transition remains to be dissected. RESULTS In the present study, a GFP (green fluorescent protein)-mTalin (mouse talin) fusion gene was introduced into suspension-cultured tobacco BY-2 (Nicotiana tabacum L. cv Bright Yellow) cells by a calli-cocultivation transformation method to visualize the reorganization of the actin cytoskeleton in vivo during the progression of the cell cycle. Typical actin structures were indicated by GFP-mTalin, such as the pre-prophase actin band, mitotic spindle actin filament cage and phragmoplast actin arrays. In addition, dynamic organization of actin filaments was observed during the progression of the cell from metaphase to anaphase. In late metaphase, spindle actin filaments gradually shrank to the equatorial plane along both the long and short axes. Soon after the separation of sister chromosomes, actin filaments aligned in parallel at the cell division plane, forming a cylinder-like structure. During the formation of the cell plate, one cylinder-like structure changed into two cylinder-like structures: the typical actin arrays of the phragmoplast. However, the two actin arrays remained overlapping at the margin of the centrally growing cell plate, forming an actin wreath. When the cell plate matured further, an actin filament network attached to the cell plate was formed. CONCLUSIONS Our results clearly describe the dynamic organization of the actin cytoskeleton during mitosis and cytokinesis of a plant cell. This demonstrates that GFP-mTalin-transformed tobacco BY-2 cells are a valuable tool to study actin cytoskeleton functions in the plant cell cycle.
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Affiliation(s)
- Miaomiao Yu
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Beijing Normal University, People's Republic of China
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26
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Sano T, Higaki T, Oda Y, Hayashi T, Hasezawa S. Appearance of actin microfilament 'twin peaks' in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP-fimbrin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 44:595-605. [PMID: 16262709 DOI: 10.1111/j.1365-313x.2005.02558.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The actin cytoskeleton of higher plants plays an essential role in plant morphogenesis and in maintaining various cellular activities. In this study we established a tobacco BY-2 cell line, stably transformed with a GFP-fimbrin actin-binding domain (ABD) 2 construct, that allows visualization of actin microfilaments (MFs) in living cells. Using this cell line, designated BY-GF11, we performed time-sequential observations of MF dynamics during cell-cycle progression. Detailed analyses revealed the appearance of a broad MF band in the late G2 phase that separated to form a structure corresponding to the so-called actin-depleted zone (ADZ) in mitosis. In BY-GF11, the MF structure at the cell cortex in mitosis appeared to form two bands rather than the ADZ. Measurements of fluorescent intensities of the cell cortex indicated an MF distribution that resembled two peaks, and we therefore named the structure MF 'twin peaks' (MFTP). The cell plate formed exactly within the valley between the MFTP at cytokinesis, and this cell-plate guidance was distorted by disruption of the MFTP by an inhibitor of actin polymerization. These results suggest that the MFTP originates from the broad MF band in the G2 phase and functions as a marker of cytokinesis.
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Affiliation(s)
- Toshio Sano
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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Yasuda H, Kanda K, Koiwa H, Suenaga K, Kidou SI, Ejiri SI. Localization of actin filaments on mitotic apparatus in tobacco BY-2 cells. PLANTA 2005; 222:118-29. [PMID: 15856282 DOI: 10.1007/s00425-005-1522-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 02/18/2005] [Indexed: 05/24/2023]
Abstract
Actin filaments are among the major components of the cytoskeleton, and participate in various cellular dynamic processes. However, conflicting results had been obtained on the localization of actin filaments on the mitotic apparatus and their participation in the process of chromosome segregation. We demonstrated by using rhodamine-phalloidin staining, the localization of actin filaments on the mitotic spindles of tobacco BY-2 cells when the cells were treated with cytochalasin D. At prophase, several clear spots were observed at or near the kinetochores of the chromosomes. At anaphase, the actin filaments that appeared to be pulling chromosomes toward the division poles were demonstrated. However, as there was a slight possibility that these results might have been the artifacts of cytochalasin D treatment or the phalloidin staining, we analyzed the localization of actin filaments at the mitotic apparatus immunologically. We cloned a novel BY-2 alpha-type actin cDNA and prepared a BY-2 actin antibody. The fluorescence of the anti-BY-2 actin antibody was clearly observed at the mitotic apparatus in both non-treated and cytochalasin D-treated BY-2 cells during mitosis. The facts that similar results were obtained in both actin staining with rhodamine-phalloidin and immunostaining with actin antibody strongly indicate the participation of actin in the organization of the spindle body or in the process of chromosome segregation. Furthermore, both filamentous actin and spindle bodies disappeared in the cells treated with propyzamide, which depolymerizes microtubules, supporting the notion that actin filaments are associated with microtubules organizing the spindle body.
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Affiliation(s)
- Hiroshi Yasuda
- Cryobiosystem Research Center, Iwate University, Morioka, Iwate 020-8550, Japan
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28
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Sheahan MB, Staiger CJ, Rose RJ, McCurdy DW. A green fluorescent protein fusion to actin-binding domain 2 of Arabidopsis fimbrin highlights new features of a dynamic actin cytoskeleton in live plant cells. PLANT PHYSIOLOGY 2004; 136:3968-78. [PMID: 15557099 PMCID: PMC535829 DOI: 10.1104/pp.104.049411] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2004] [Revised: 10/06/2004] [Accepted: 10/12/2004] [Indexed: 05/18/2023]
Abstract
The actin cytoskeleton coordinates numerous cellular processes required for plant development. The functions of this network are intricately linked to its dynamic arrangement, and thus progress in understanding how actin orchestrates cellular processes relies on critical evaluation of actin organization and turnover. To investigate the dynamic nature of the actin cytoskeleton, we used a fusion protein between green fluorescent protein (GFP) and the second actin-binding domain (fABD2) of Arabidopsis (Arabidopsis thaliana) fimbrin, AtFIM1. The GFP-fABD2 fusion protein labeled highly dynamic and dense actin networks in diverse species and cell types, revealing structural detail not seen with alternative labeling methods, such as the commonly used mouse talin GFP fusion (GFP-mTalin). Further, we show that expression of the GFP-fABD2 fusion protein in Arabidopsis, unlike GFP-mTalin, has no detectable adverse effects on plant morphology or development. Time-lapse confocal microscopy and fluorescence recovery after photobleaching analyses of the actin cytoskeleton labeled with GFP-fABD2 revealed that lateral-filament migration and sliding of individual actin filaments or bundles are processes that contribute to the dynamic and continually reorganizing nature of the actin scaffold. These new observations of the dynamic actin cytoskeleton in plant cells using GFP-fABD2 reveal the value of this probe for future investigations of how actin filaments coordinate cellular processes required for plant development.
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Affiliation(s)
- Michael B Sheahan
- School of Environmental and Life Sciences , The University of Newcastle, Callaghan, New South Wales, 2308 Australia
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29
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Liu AX, Zhang SB, Xu XJ, Ren DT, Liu GQ. Soluble expression and characterization of a GFP-fused pea actin isoform (PEAc1). Cell Res 2004; 14:407-14. [PMID: 15538972 DOI: 10.1038/sj.cr.7290241] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A pea actin isoform PEAc1 with green fluorescent protein (GFP) fusion to its C-terminus and His-tag to its N-terminus, was expressed in prokaryotic cells in soluble form, and highly purified with Ni-Chelating Sepharose Fast Flow column. The purified fusion protein (PEAc1-GFP) efficiently inhibited DNase I activities before polymerization, and activated the myosin Mg-ATPase activities after polymerization. The PEAc1-GFP also polymerized into green fluorescent filamentous structures with a critical concentration of 0.75 uM. These filamentous structures were labeled by TRITC-phalloidin, a specific agent for staining actin microfilaments, and identified as having 9 nm diameters by negative staining. These results indicated that PEAc1 preserved the essential characteristics of actin even with His-tag and GFP fusion, suggesting a promising potential to use GFP fusion protein in obtaining soluble plant actin isoform to analyze its physical and biochemical properties in vitro. The PEAc1-GFP was also expressed in tobacco BY2 cells, which offers a new pathway for further studying its distribution and function in vivo.
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Affiliation(s)
- Ai Xiao Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Science, China Agricultural University, Beijing 100094, China.
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30
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Forer A, Spurck T, Pickett-Heaps JD, Wilson PJ. Structure of kinetochore fibres in crane-fly spermatocytes after irradiation with an ultraviolet microbeam: Neither microtubules nor actin filaments remain in the irradiated region. ACTA ACUST UNITED AC 2003; 56:173-92. [PMID: 14569597 DOI: 10.1002/cm.10144] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We studied chromosome movement after kinetochore microtubules were severed. Severing a kinetochore fibre in living crane-fly spermatocytes with an ultraviolet microbeam creates a kinetochore stub, a birefringent remnant of the spindle fibre connected to the kinetochore and extending only to the edge of the irradiated region. After the irradiation, anaphase chromosomes either move poleward led by their stubs or temporarily stop moving. We examined actin and/or microtubules in irradiated cells by means of confocal fluorescence microscopy or serial-section reconstructions from electron microscopy. For each cell thus examined, chromosome movement had been recorded continuously until the moment of fixation. Kinetochore microtubules were completely severed by the ultraviolet microbeam in cells in which chromosomes continued to move poleward after the irradiation: none were seen in the irradiated regions. Similarly, actin filaments normally present in kinetochore fibres were severed by the ultraviolet microbeam irradiations: the irradiated regions contained no actin filaments and only local spots of non-filamentous actin. There was no difference in irradiated regions when the associated chromosomes continued to move versus when they stopped moving. Thus, one cannot explain motion with severed kinetochore microtubules in terms of either microtubules or actin-filaments bridging the irradiated region. The data seem to negate current models for anaphase chromosome movement and support a model in which poleward chromosome movement results from forces generated within the spindle matrix that propel kinetochore fibres or kinetochore stubs poleward.
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Affiliation(s)
- Arthur Forer
- Biology Department, York University, Toronto, Ontario, Canada.
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31
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Scherp P, Hasenstein KH. Microinjection--a tool to study gravitropism. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 2003; 31:2221-2227. [PMID: 14686436 DOI: 10.1016/s0273-1177(03)00248-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Despite extensive studies on plant gravitropism this phenomenon is still poorly understood. The separation of gravity sensing, signal transduction and response is a common concept but especially the mechanism of gravisensing remains unclear. This paper focuses on microinjection as powerful tool to investigate gravisensing in plants. We describe the microinjection of magnetic beads in rhizoids of the green alga Chara and related subsequent manipulation of the gravisensing system. After injection, an external magnet can control the movement of the magnetic beads. We demonstrate successful injection of magnetic beads into rhizoids and describe a multitude of experiments that can be carried out to investigate gravitropism in Chara rhizoids. In addition to examining mechanical properties, bead microinjection is also useful for probing the function of the cytoskeleton by coating beads with drugs that interfere with the cytoskeleton. The injection of fluorescently labeled beads or probes may reveal the involvement of the cytoskeleton during gravistimulation and response in living cells.
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Affiliation(s)
- P Scherp
- Biology Department, University of Louisiana at Lafayette, LA 70504-2451, USA
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32
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Van Gestel K, Le J, Verbelen JP. A comparison of F-actin labeling methods for light microscopy in different plant specimens: multiple techniques supplement each other. Micron 2001; 32:571-8. [PMID: 11166577 DOI: 10.1016/s0968-4328(00)00054-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Different detection methods for F-actin labeling were compared on a range of plant specimens: cultured cells, whole organ mounts and sectioned material. For cultured cells, microinjection of labeled phalloidin yielded the most detailed picture but careful permeation methods come close, while immunocytochemical methods always gave relatively poor detail, especially on the level of the fine filaments. For whole organ mounts and sectioned material, permeation methods and immunolocalization are the methods of choice, however never reaching the level of resolution of permeation methods in single cells. It is clear that there is no general and universal good method and multiple techniques are needed, especially when working with different specimens and with different aims.
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Affiliation(s)
- K Van Gestel
- Department of Biology, University of Antwerp, UIA, Universiteitsplein 1, B-2610 Wilrijk, Antwerp, Belgium
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33
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Expression ofChlamydomonas actin-gfp fusion gene in tobacco suspension cell and polymerization of the actin-gfp proteinin vitro. ACTA ACUST UNITED AC 2001. [DOI: 10.1007/bf02900428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
This first analysis of monocotyledon myosin genes showed that at least five genes, one of which was probably spliced to yield two isoforms, were expressed in maize (Zea mays L.). The complete coding sequence of ZMM1 was determined, as were most of the sequences of two other myosin cDNAs (ZMM2 and ZMM3). ZMM1 and ZMM2 belonged to myosin class XI while ZMM3 was in class VIII. ZMM1 was abundantly expressed in leaves, roots, coleoptiles, and stems. ZMM3 showed a similar distribution but was expressed poorly in pollen. ZMM2 was predominantly expressed in seeds and may be part of a suite of cytoskeletal proteins in reproductive tissues. Phylogenetic analysis suggested that the origin of myosin classes VIII and XI predated that of angiosperms. Immunofluorescence studies using M11L1, a myosin XI antibody specific for the exposed loop 1 head region of myosin, indicated that myosin XI occurred in the cytoplasm of all root tip cells. The highest concentration of myosin XI was in the differentiating epidermal cells. In dividing cells, myosin XI was present near the cytokinetic apparatus at approximately the same concentration seen in other portions of the cytoplasm. Western blot analysis of subcellular fractions indicated that myosin XI was concentrated in mitochondria and low-density membranes.
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Affiliation(s)
- L Liu
- Biological Laboratories, Harvard University, Cambridge, Massachusetts, USA
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35
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Canaday J, Stoppin-Mellet V, Mutterer J, Lambert AM, Schmit AC. Higher plant cells: gamma-tubulin and microtubule nucleation in the absence of centrosomes. Microsc Res Tech 2000; 49:487-95. [PMID: 10842376 DOI: 10.1002/(sici)1097-0029(20000601)49:5<487::aid-jemt11>3.0.co;2-i] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The assembly of the higher plant cytoskeleton poses several fundamental questions. Since different microtubule arrays are successively assembled during the cell cycle in the absence of centrosomes, we can ask how these arrays are assembled and spatially organized. Two hypotheses are under debate. Either multiple nucleation sites are responsible for the assembly and organization of microtubule arrays or microtubule nucleation takes place at one site, the nuclear surface. In the latter case, microtubule nucleation and organization would be two distinct but coregulated processes. During recent years, novel approaches have provided entirely new insights to understand the assembly and dynamics of the plant cytoskeleton. In the present review, we summarize advances made in microscopy and in molecular biology which lead to novel hypotheses and open up new fields of investigation. From the results obtained, it is clear that the higher plant cell is a powerful model system to investigate cytoskeletal organization in acentrosomal eukaryotic cells.
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Affiliation(s)
- J Canaday
- Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Université Louis Pasteur, Strasbourg, France
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36
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Abstract
Growth and development of all plant cells and organs relies on a fully functional cytoskeleton comprised principally of microtubules and microfilaments. These two polymeric macromolecules, because of their location within the cell, confer structure upon, and convey information to, the peripheral regions of the cytoplasm where much of cellular growth is controlled and the formation of cellular identity takes place. Other ancillary molecules, such as motor proteins, are also important in assisting the cytoskeleton to participate in this front-line work of cellular development. Roots provide not only a ready source of cells for fundamental analyses of the cytoskeleton, but the formative zone at their apices also provides a locale whereby experimental studies can be made of how the cytoskeleton permits cells to communicate between themselves and to cooperate with growth-regulating information supplied from the apoplasm.
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Affiliation(s)
- Peter W. Barlow
- IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol BS41 9AF, United Kingdom; e-mail: , Botanisches Institut, Rheinische Friedrich-Wilhelms-Universitat Bonn, Kirschallee 1, D-53115 Bonn, Germany; e-mail:
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37
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Abstract
The plant actin cytoskeleton is characterized by a high diversity in regard to gene families, isoforms, and degree of polymerization. In addition to the most abundant F-actin assemblies like filaments and their bundles, G-actin obviously assembles in the form of actin oligomers composed of a few actin molecules which can be extensively cross-linked into complex dynamic meshworks. The role of the actomyosin complex as a force generating system - based on principles operating as in muscle cells - is clearly established for long-range mass transport in large algal cells and specialized cell types of higher plants. Extended F-actin networks, mainly composed of F-actin bundles, are the structural basis for this cytoplasmic streaming of high velocities On the other hand, evidence is accumulating that delicate meshworks built of short F-actin oligomers are critical for events occurring at the plasma membrane, e.g., actin interventions into activities of ion channels and hormone carriers, signaling pathways based on phospholipids, and exo- and endocytotic processes. These unique F-actin arrays, constructed by polymerization-depolymerization processes propelled via synergistic actions of actin-binding proteins such as profilin and actin depolymerizing factor (ADF)/cofilin are supposed to be engaged in diverse aspects of plant morphogenesis. Finally, rapid rearrangements of F-actin meshworks interconnecting endocellular membranes turn out to be especially important for perception-signaling purposes of plant cells, e.g., in association with guard cell movements, mechano- and gravity-sensing, plant host-pathogen interactions, and wound-healing.
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Affiliation(s)
- D Volkmann
- Botany Institute, University of Bonn, Germany.
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38
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Affiliation(s)
- J W Vos
- Department of Biology, University of Massachusetts, Amherst 01003, USA
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39
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Kost B, Spielhofer P, Chua NH. A GFP-mouse talin fusion protein labels plant actin filaments in vivo and visualizes the actin cytoskeleton in growing pollen tubes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1998; 16:393-401. [PMID: 9881160 DOI: 10.1046/j.1365-313x.1998.00304.x] [Citation(s) in RCA: 293] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The C-terminus of mouse talin (amino acids 2345-2541) is responsible for all of the protein's f-actin binding capacity. Unlike full-length talin, the C-terminal f-actin binding domain is unable to nucleate actin polymerization. We have found that transient and stable expression of the talin actin-binding domain fused to the C-terminus of the green fluorescent protein (GFP-mTn) can visualize the actin cytoskeleton in different types of living plant cells without affecting cell morphology or function. Transiently expressed GFP-mTn co-localized with rhodamine-phalloidin in permeabilized tobacco BY-2 suspension cells, showing that the fusion protein can specifically label the plant actin cytoskeleton. Constitutive expression of GFP-mTn in transgenic Arabidopsis thaliana plants visualized actin filaments in all examined tissues with no apparent effects on plant morphology or development at any stage during the life cycle. This demonstrates that in a number of different cell types GFP-mTn can serve as a non-invasive marker for the actin cytoskeleton. Confocal imaging of GFP-mTn labeled actin filaments was employed to reveal novel information on the in vivo organization of the actin cytoskeleton in transiently transformed, normally elongating tobacco pollen tubes.
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Affiliation(s)
- B Kost
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021-6399, USA
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40
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Forer A, Pickett-Heaps JD. Cytochalasin D and latrunculin affect chromosome behaviour during meiosis in crane-fly spermatocytes. Chromosome Res 1998; 6:533-49. [PMID: 9886773 DOI: 10.1023/a:1009224322399] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Living crane-fly spermatocytes were treated with 10-20 microg/ml cytochalasin D (CD) or 0.3 microg/ml latrunculin (LAT) at various stages of meiosis I. The drugs had the same effects on chromosome behaviour, but CD effects were reversible and LAT effects generally were not. When applied in mid-prometaphase to metaphase, both drugs altered subsequent anaphase poleward movements: half-bivalents either moved more slowly than normal, or moved more slowly after a brief period of movement at normal rate or stalled for 10 min or more immediately after disjunction. CD effects were reversible: within 1 min after washing out the CD, stopped chromosomes started moving and slowed chromosomes sped up. When applied in anaphase, both drugs stopped or slowed poleward chromosome movements, usually reversibly. When applied near the end of prophase, both drugs often prevented one or more bivalents in the cell from attaching to the spindle. Attached bivalents behaved as in cells treated with drugs at later stages, as described above. Unattached bivalents in the same cells moved to poles or cytoplasm in early prometaphase, where they remained motionless; at anaphase they sometimes did not disjoin, but when they did disjoin the half-bivalents did not move, either in the continued presence of the drug or when CD was washed out, confirming that they were not atttached. When CD or LAT prevented all bivalents in the cell from attaching, spindles kept in the drug were invaded by granules at about the time of normal anaphase. Conversely, when CD was washed out during late prometaphase, chromosomes often attached to spindle fibres and later entered anaphase. As CD and LAT are different antiactin drugs, but have the same effect on chromosome behaviour, the results implicate actin in early interactions of chromosomes with spindle fibres and in anaphase chromosome movements.
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Affiliation(s)
- A Forer
- Biology Department, York University, Downsview, Ontario, Canada.
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41
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Jackson SL, Hardham AR. Dynamic rearrangement of the filamentous actin network occurs during zoosporogenesis and encystment in the oomycete phytophthora cinnamomi. Fungal Genet Biol 1998; 24:24-33. [PMID: 9742190 DOI: 10.1006/fgbi.1998.1071] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The organization of filamentous actin (F-actin) in living cells of the oomycete Phytophthora cinnamomi was determined during zoosporogenesis and zoospore encystment by microinjecting sporangia with fluorescently labeled phalloidin and observing resultant fluorescence by confocal microscopy. In multinucleate sporangia prior to the induction of cleavage, phalloidin labeling took the form of plaques which occurred mainly in the periphery of the sporangia. After induction of cleavage, phalloidin labeling showed that the plaques disappeared and that F-actin began to accumulate along the developing cleavage planes and around nuclei and water expulsion vacuoles. F-actin labeling was also observed near the plasma membrane in zoospores and young cysts but reverted to the plaque form in older cysts. Localization of F-actin close to the developing cleavage planes is consistent with the idea that actin microfilaments function in the positioning and expansion of the cleavage membranes. Observations of plaques of actin in living sporangia provide evidence that plaques are not aldehyde-induced fixation artifacts. Copyright 1998 Academic Press.
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Affiliation(s)
- SL Jackson
- Research School of Biological Sciences, The Australian National University, Canberra, ACT, 2601, Australia
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42
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Vaughn KC, Harper JD. Microtubule-organizing centers and nucleating sites in land plants. INTERNATIONAL REVIEW OF CYTOLOGY 1998; 181:75-149. [PMID: 9522456 DOI: 10.1016/s0074-7696(08)60417-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Microtubule-organizing centers (MTOCs) are morphologically diverse cellular sites involved in the nucleation and organization of microtubules (MTs). These structures are synonymous with the centrosome in mammalian cells. In most land plant cells, however, no such structures are observed and some have argued that plant cells may not have MTOCs. This review summarizes a number of experimental approaches toward the elucidation of those subcellular sites involved in microtubule nucleation and organization. In lower land plants, structurally well-defined MTOCs are present, such as the blepharoplast, multilayered structure, and polar organizer. In higher plants, much of the nucleation and organization of MTs occurs on the nuclear envelope or other endomembranes, such as the plasmalemma and smooth (tubular) endoplasmic reticulum. In some instances, one endomembrane may serve as a site of nucleation whereas others serve as the site of organization. Structural and motor microtubule-associated proteins also appear to be involved in MT nucleation and organization. Immunochemical evidence indicates that at least several of the proteins found in mammalian centrosomes, gamma-tubulin, centrin, pericentrin, and polypeptides recognized by the monoclonal antibodies MPM-2, 6C6, and C9 also recognize putative lower land plant MTOCs, indicating shared mechanisms of nucleation/organization in plants and animals. The most recent data from tubulin incorporation in vivo, mutants with altered MT organization, and molecular studies indicate the potential of these research tools in investigation of MTOCs in plants.
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Affiliation(s)
- K C Vaughn
- Southern Weed Science Laboratory, USDA-ARS, Stoneville, Mississippi 38776, USA
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43
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Morelli JK, Zhou W, Yu J, Lu C, Vayda ME. Actin depolymerization affects stress-induced translational activity of potato tuber tissue. PLANT PHYSIOLOGY 1998; 116:1227-37. [PMID: 9536039 PMCID: PMC35029 DOI: 10.1104/pp.116.4.1227] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/1997] [Accepted: 12/07/1997] [Indexed: 05/21/2023]
Abstract
Changes in polymerized actin during stress conditions were correlated with potato (Solanum tuberosum L.) tuber protein synthesis. Fluorescence microscopy and immunoblot analyses indicated that filamentous actin was nearly undetectable in mature, quiescent aerobic tubers. Mechanical wounding of postharvest tubers resulted in a localized increase of polymerized actin, and microfilament bundles were visible in cells of the wounded periderm within 12 h after wounding. During this same period translational activity increased 8-fold. By contrast, low-oxygen stress caused rapid reduction of polymerized actin coincident with acute inhibition of protein synthesis. Treatment of aerobic tubers with cytochalasin D, an agent that disrupts actin filaments, reduced wound-induced protein synthesis in vivo. This effect was not observed when colchicine, an agent that depolymerizes microtubules, was used. Neither of these drugs had a significant effect in vitro on run-off translation of isolated polysomes. However, cytochalasin D did reduce translational competence in vitro of a crude cellular fraction containing both polysomes and cytoskeletal elements. These results demonstrate the dependence of wound-induced protein synthesis on the integrity of microfilaments and suggest that the dynamics of the actin cytoskeleton may affect translational activity during stress conditions.
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Affiliation(s)
- JK Morelli
- Department of Biochemistry, Microbiology and Molecular Biology, University of Maine, Orono, Maine 04469-5735, USA
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44
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Valster AH, Pierson ES, Valenta R, Hepler PK, Emons AMC. Probing the Plant Actin Cytoskeleton during Cytokinesis and Interphase by Profilin Microinjection. THE PLANT CELL 1997; 9:1815-1824. [PMID: 12237348 PMCID: PMC157024 DOI: 10.1105/tpc.9.10.1815] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We have examined the cytological effects of microinjecting recombinant birch profilin in dividing and interphase stamen hair cells of Tradescantia virginiana. Microinjection of profilin at anaphase and telophase led to a marked effect on cytokinesis; cell plate formation was often delayed, blocked, or completely inhibited. In addition, the initial appearance of the cell plate was wrinkled, thin, and sometimes fragmented. Injection of profilin at interphase caused a thinning or the collapse of cytoplasmic strands and a retardation or inhibition of cytoplasmic streaming in a dose-dependent manner. Confocal laser scanning microscopy of rhodamine-phalloidin staining in vivo revealed that high levels of microinjected profilin induced a degradation of the actin cytoskeleton in the phragmoplast, the perinuclear zone, and the cytoplasmic strands. However, some cortical actin filaments remained intact. The data demonstrate that profilin has the ability to act as a regulator of actin-dependent events and that centrally located actin filaments are more sensitive to microinjected profilin than are cortical actin filaments. These results add new evidence supporting the hypothesis that actin filaments play a crucial role in the formation of the cell plate and provide mechanical support for the cytoplasmic strands in interphase cells.
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Affiliation(s)
- A. H. Valster
- Department of BioMolecular Sciences, Wageningen Agricultural University, Arboretumlaan 4, NL-6703 BD Wageningen, The Netherlands
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45
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Reuzeau C, Doolittle KW, McNally JG, Pickard BG. Covisualization in living onion cells of putative integrin, putative spectrin, actin, putative intermediate filaments, and other proteins at the cell membrane and in an endomembrane sheath. PROTOPLASMA 1997; 199:173-97. [PMID: 11541651 DOI: 10.1007/bf01294505] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Covisualizations with wide-field computational optical-sectioning microscopy of living epidermal cells of the onion bulb scale have evidenced two major new cellular features. First, a sheath of cytoskeletal elements clads the endomembrane system. Similar elements clad the inner faces of punctate plasmalemmal sites interpreted as plasmalemmal control centers. One component of the endomembrane sheath and plasmalemmal control center cladding is anti-genicity-recognized by two injected antibodies against animal spectrin. Immunoblots of separated epidermal protein also showed bands recognized by these antibodies. Injected phalloidin identified F-actin with the same cellular distribution pattern, as did antibodies against intermediate-filament protein and other cytoskeletal elements known from animal cells. Injection of general protein stains demonstrated the abundance of endomembrane sheath protein. Second, the endomembrane system, like the plasmalemmal puncta, contains antigen recognized by an anti-beta 1 integrin injected into the cytoplasm. Previously, immunoblots of separated epidermal protein were shown to have a major band recognized both by this antibody prepared against a peptide representing the cytosolic region of beta 1 integrin and an antibody against the matrix region of beta 1 integrin. The latter antiboby also identified puncta at the external face of protoplasts. It is proposed that integrin and associated transmembrane proteins secure the endomembrane sheath and transmit signals between it and the lumen or matrix of the endoplasmic reticulum and organellar matrices. This function is comparable to that proposed for such transmembrane linkers in the plasmalemmal control centers, which also appear to bind cytoskeleton and a host of related molecules and transmit signals between them and the wall matrix. It is at the plasmalemmal control centers that the endoplasmic reticulum, a major component of the endomembrane system, attaches to the plasma membrane.
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Affiliation(s)
- C Reuzeau
- Biology Department, Washington University, Saint Louis, Missouri, USA
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46
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Gavin RH. Microtubule-microfilament synergy in the cytoskeleton. INTERNATIONAL REVIEW OF CYTOLOGY 1997; 173:207-42. [PMID: 9127954 DOI: 10.1016/s0074-7696(08)62478-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This review describes examples of structural and functional synergy of the microtubule and actin filament cytoskeleton. An analysis of basal body (centriole)-associated fibrillar networks includes studies of ciliated epithelium, neurosensory epithelium, centrosomes, and ciliated protozoa. Microtubule and actin filament interactions in cell division and development are illustrated by centrosome motility, cleavage furrow positioning, centriole migration, nuclear migration, dynamics in the phragmoplast, growth cone motility, syncytial organization, and ring canals. Model systems currently used for studies on organelle transport are described in relation to mitochondrial transport in axons and vesicular transport in polarized epithelium. Evidence that both anterograde and retrograde motors are associated with one organelle is also discussed. The final section reviews proteins that bind both microtubules and actin filaments and are possible regulators of microtubule-microfilament interactions. Regulatory roles for posttranslational modifications, microtubule and microfilament dynamics, and multisubunit complexes are considered.
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Affiliation(s)
- R H Gavin
- Department of Biology, Brooklyn College, City University of New York 11210, USA
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47
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Liu B, Cyr RJ, Palevitz BA. A kinesin-like protein, KatAp, in the cells of arabidopsis and other plants. THE PLANT CELL 1996; 8:119-132. [PMID: 8597656 PMCID: PMC161086 DOI: 10.1105/tpc.8.1.119] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The kinesin-like proteins (KLPs) are a large family of plus- or minus-end-directed microtubule motors important in intracellular transport, mitosis, meiosis, and development. However, relatively little is known about plant KLPs. We prepared an antibody against two peptides in the microtubule binding domain of an Arabidopsis KLP (KatAp) encoded by the KatA gene, one of a family of genes encoding KLPs whose motor domain is located near the C terminus of the polypeptide. Such KLPs typically move materials toward the minus end of microtubules. An immunoreactive band (Mr of 140,000) corresponding to KatAp was demonstrated with this antibody on immunoblots of Arabidopsis seedling extracts. During immunofluorescence localizations, the antibody produced weak, variable staining in the cytoplasm and nucleus of interphase Arabidopsis suspension cells but much stronger staining of the mitotic apparatus during division. Staining was concentrated near the midzone during metaphase and was retained there during anaphase. The phragmoplast was also stained. Similar localization patterns were seen in tobacco BY-2 cells. The antibody produced a single band (Mr of 130,000) in murine brain fractions prepared according to procedures that enrich for KLPs (binding to microtubules in the presence of AMP-PNP but not ATP). A similar fraction from carrot suspension cells yielded a cross-reacting polypeptide of similar apparent molecular mass. When dividing BY-2 cells were lysed in the presence of taxol and ATP, antibody staining moved rapidly toward the poles, supporting the presence of a minus-end motor. Movement did not occur without ATP, with AMP-PNP, or with ATP plus antibody. Our results indicate that the protein encoded by KatA, KatAp, is expressed in Arabidopsis and is specifically localized to the midzone of the mitotic apparatus and phragmoplast. A similar protein is also present in other species.
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Affiliation(s)
- B Liu
- Department of Botany, University of Georgia, Athens 30602, USA
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48
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Liu B, Cyr RJ, Palevitz BA. A kinesin-like protein, KatAp, in the cells of arabidopsis and other plants. THE PLANT CELL 1996. [PMID: 8597656 DOI: 10.2307/3870073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The kinesin-like proteins (KLPs) are a large family of plus- or minus-end-directed microtubule motors important in intracellular transport, mitosis, meiosis, and development. However, relatively little is known about plant KLPs. We prepared an antibody against two peptides in the microtubule binding domain of an Arabidopsis KLP (KatAp) encoded by the KatA gene, one of a family of genes encoding KLPs whose motor domain is located near the C terminus of the polypeptide. Such KLPs typically move materials toward the minus end of microtubules. An immunoreactive band (Mr of 140,000) corresponding to KatAp was demonstrated with this antibody on immunoblots of Arabidopsis seedling extracts. During immunofluorescence localizations, the antibody produced weak, variable staining in the cytoplasm and nucleus of interphase Arabidopsis suspension cells but much stronger staining of the mitotic apparatus during division. Staining was concentrated near the midzone during metaphase and was retained there during anaphase. The phragmoplast was also stained. Similar localization patterns were seen in tobacco BY-2 cells. The antibody produced a single band (Mr of 130,000) in murine brain fractions prepared according to procedures that enrich for KLPs (binding to microtubules in the presence of AMP-PNP but not ATP). A similar fraction from carrot suspension cells yielded a cross-reacting polypeptide of similar apparent molecular mass. When dividing BY-2 cells were lysed in the presence of taxol and ATP, antibody staining moved rapidly toward the poles, supporting the presence of a minus-end motor. Movement did not occur without ATP, with AMP-PNP, or with ATP plus antibody. Our results indicate that the protein encoded by KatA, KatAp, is expressed in Arabidopsis and is specifically localized to the midzone of the mitotic apparatus and phragmoplast. A similar protein is also present in other species.
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Affiliation(s)
- B Liu
- Department of Botany, University of Georgia, Athens 30602, USA
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49
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The plant cytoskeleton. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s1874-6020(96)80016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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50
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Claassen DE, Spooner BS. Impact of altered gravity on aspects of cell biology. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 156:301-73. [PMID: 7860219 DOI: 10.1016/s0074-7696(08)62257-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- D E Claassen
- Kansas State University, Division of Biology, Manhattan 66506-4901
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