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Jawahar A, Vermeil J, Heuvingh J, du Roure O, Piel M. The third dimension of the actin cortex. Curr Opin Cell Biol 2024; 89:102381. [PMID: 38905917 DOI: 10.1016/j.ceb.2024.102381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/15/2024] [Accepted: 05/24/2024] [Indexed: 06/23/2024]
Abstract
The actin cortex, commonly described as a thin 2-dimensional layer of actin filaments beneath the plasma membrane, is beginning to be recognized as part of a more dynamic and three-dimensional composite material. In this review, we focus on the elements that contribute to the three-dimensional architecture of the actin cortex. We also argue that actin-rich structures such as filopodia and stress fibers can be viewed as specialized integral parts of the 3D actin cortex. This broadens our definition of the cortex, shifting from its simplified characterization as a thin, two-dimensional layer of actin filaments.
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Affiliation(s)
- Anumita Jawahar
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France.
| | - Joseph Vermeil
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
| | - Julien Heuvingh
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Olivia du Roure
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Matthieu Piel
- Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
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2
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Winkelmann H, Richter CP, Eising J, Piehler J, Kurre R. Correlative single-molecule and structured illumination microscopy of fast dynamics at the plasma membrane. Nat Commun 2024; 15:5813. [PMID: 38987559 PMCID: PMC11236984 DOI: 10.1038/s41467-024-49876-9] [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: 09/25/2023] [Accepted: 06/21/2024] [Indexed: 07/12/2024] Open
Abstract
Total internal reflection fluorescence (TIRF) microscopy offers powerful means to uncover the functional organization of proteins in the plasma membrane with very high spatial and temporal resolution. Traditional TIRF illumination, however, shows a Gaussian intensity profile, which is typically deteriorated by overlaying interference fringes hampering precise quantification of intensities-an important requisite for quantitative analyses in single-molecule localization microscopy (SMLM). Here, we combine flat-field illumination by using a standard πShaper with multi-angular TIR illumination by incorporating a spatial light modulator compatible with fast super-resolution structured illumination microscopy (SIM). This distinct combination enables quantitative multi-color SMLM with a highly homogenous illumination. By using a dual camera setup with optimized image splitting optics, we achieve a versatile combination of SMLM and SIM with up to three channels. We deploy this setup for establishing robust detection of receptor stoichiometries based on single-molecule intensity analysis and single-molecule Förster resonance energy transfer (smFRET). Homogeneous illumination furthermore enables long-term tracking and localization microscopy (TALM) of cell surface receptors identifying spatial heterogeneity of mobility and accessibility in the plasma membrane. By combination of TALM and SIM, spatially and molecularly heterogenous diffusion properties can be correlated with nanoscale cytoskeletal organization and dynamics.
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Affiliation(s)
- Hauke Winkelmann
- Division of Biophysics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany
| | - Christian P Richter
- Division of Biophysics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany
| | - Jasper Eising
- Division of Biophysics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany
| | - Jacob Piehler
- Division of Biophysics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany.
- Center for Cellular Nanoanalytics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany.
| | - Rainer Kurre
- Division of Biophysics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany.
- Center for Cellular Nanoanalytics, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany.
- Integrated Bioimaging Facility iBiOs, Department of Biology/Chemistry, Osnabrück University, Barbarastraße 11, D-49076, Osnabrück, Germany.
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Naveed ZA, Jamil M, Asif N, Waqas M, Ajaz S, Khan SH. Cross-regulation of cytoskeleton and calcium signaling at plant-pathogen interface. Cell Signal 2024; 117:111100. [PMID: 38360248 DOI: 10.1016/j.cellsig.2024.111100] [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: 10/09/2023] [Revised: 02/06/2024] [Accepted: 02/12/2024] [Indexed: 02/17/2024]
Abstract
During plant-pathogen interactions, cytoskeleton and calcium signaling work independently as well as in coordination with each other for developing preformed and induced defense responses. A cell wall (CW) - plasma membrane (PM) - cytoskeleton (CS) continuum is maintained by coordination of cytoskeleton and calcium signaling. The current review is focused on the current knowledge of cytoskeleton‑calcium cross-regulation during plant-pathogen interactions. Implications of recent technological developments in the existing toolkit that can address the outstanding questions of cytoskeleton‑calcium coordination plant immunity are also discussed.
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Affiliation(s)
- Zunaira Afzal Naveed
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan; Center of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Pakistan
| | - Mahnoor Jamil
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Nouman Asif
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Muhammad Waqas
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Sobia Ajaz
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan
| | - Sultan Habibullah Khan
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad, Pakistan; Center of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Pakistan.
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Desroches S, Harris AR. Quantifying cytoskeletal organization from optical microscopy data. Front Cell Dev Biol 2024; 11:1327994. [PMID: 38234685 PMCID: PMC10792062 DOI: 10.3389/fcell.2023.1327994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/07/2023] [Indexed: 01/19/2024] Open
Abstract
The actin cytoskeleton plays a pivotal role in a broad range of physiological processes including directing cell shape and subcellular organization, determining cell mechanical properties, and sensing and transducing mechanical forces. The versatility of the actin cytoskeleton arises from the ability of actin filaments to assemble into higher order structures through their interaction with a vast set of regulatory proteins. Actin filaments assemble into bundles, meshes, and networks, where different combinations of these structures fulfill specific functional roles. Analyzing the organization and abundance of different actin structures from optical microscopy data provides a valuable metric for assessing cell physiological function and changes associated with disease. However, quantitative measurements of the size, abundance, orientation, and distribution of different types of actin structure remains challenging both from an experimental and image analysis perspective. In this review, we summarize image analysis methods for extracting quantitative values that can be used for characterizing the organization of actin structures and provide selected examples. We summarize the potential sample types and metric reported with different approaches as a guide for selecting an image analysis strategy.
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Affiliation(s)
- Sarah Desroches
- Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, ON, Canada
- Ottawa-Carleton Institute for Biomedical Engineering Graduate Program, Ottawa, ON, Canada
| | - Andrew R. Harris
- Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, ON, Canada
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Wen G, Lycas MD, Jia Y, Leen V, Sauer M, Hofkens J. Trifunctional Linkers Enable Improved Visualization of Actin by Expansion Microscopy. ACS NANO 2023; 17:20589-20600. [PMID: 37787755 DOI: 10.1021/acsnano.3c07510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Expansion microscopy (ExM) revolutionized the field of super-resolution microscopy by allowing for subdiffraction resolution fluorescence imaging on standard fluorescence microscopes. However, it has been found that it is hard to visualize actin filaments efficiently using ExM. To improve actin imaging, multifunctional molecules have been designed with moderate success. Here, we present optimized methods for phalloidin conjugate grafting that have a high efficiency for both cellular and tissue samples. Our optimized strategy improves anchoring and signal retention by ∼10 times. We demonstrate the potential of optimized trifunctional linkers (TRITON) for actin imaging in combination with immunolabeling using different ExM protocols. 10X ExM of actin labeled with optimized TRITON enabled us to visualize the periodicity of actin rings in cultured hippocampal neurons and brain slices by Airyscan confocal microscopy. Thus, TRITON linkers provide an efficient grafting method, especially in cases in which the concentration of target-bound monomers is insufficient for high-quality ExM.
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Affiliation(s)
- Gang Wen
- Department of Chemistry, KU Leuven, Leuven, 3001, Belgium
- Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Matthew Domenic Lycas
- Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Yuqing Jia
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, Netherlands
| | - Volker Leen
- Chrometra Scientific, Kortenaken 3470, Belgium
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
- Rudolf Virchow Center, Research Center for Integrative and Translational Bioimaging, University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| | - Johan Hofkens
- Department of Chemistry, KU Leuven, Leuven, 3001, Belgium
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
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Pugliese LA, De Lorenzi V, Bernardi M, Ghignoli S, Tesi M, Marchetti P, Pesce L, Cardarelli F. Unveiling nanoscale optical signatures of cytokine-induced β-cell dysfunction. Sci Rep 2023; 13:13342. [PMID: 37587148 PMCID: PMC10432522 DOI: 10.1038/s41598-023-40272-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/08/2023] [Indexed: 08/18/2023] Open
Abstract
Pro-inflammatory cytokines contribute to β-cell failure in both Type-1 and Type-2 Diabetes. Data collected so far allowed to dissect the genomic, transcriptomic, proteomic and biochemical landscape underlying cytokine-induced β-cell progression through dysfunction. Yet, no report thus far complemented such molecular information with the direct optical nanoscopy of the β-cell subcellular environment. Here we tackle this issue in Insulinoma 1E (INS-1E) β-cells by label-free fluorescence lifetime imaging microscopy (FLIM) and fluorescence-based super resolution imaging by expansion microscopy (ExM). It is found that 24-h exposure to IL-1β and IFN-γ is associated with a neat modification of the FLIM signature of cell autofluorescence due to the increase of either enzyme-bound NAD(P)H molecules and of oxidized lipid species. At the same time, ExM-based direct imaging unveils neat alteration of mitochondrial morphology (i.e. ~ 80% increase of mitochondrial circularity), marked degranulation (i.e. ~ 40% loss of insulin granules, with mis-localization of the surviving pool), appearance of F-actin-positive membrane blebs and an hitherto unknown extensive fragmentation of the microtubules network (e.g. ~ 37% reduction in the number of branches). Reported observations provide an optical-microscopy framework to interpret the amount of molecular information collected so far on β-cell dysfunction and pave the way to future ex-vivo and in-vivo investigations.
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Affiliation(s)
- Licia Anna Pugliese
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy.
| | - Valentina De Lorenzi
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy
| | - Mario Bernardi
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy
| | - Samuele Ghignoli
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy
| | - Marta Tesi
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Luca Pesce
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy.
| | - Francesco Cardarelli
- NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy.
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Segretain D, Di Marco M, Dufeu C, Carette D, Trubuil A, Pointis G. Cooperative cell-cell actin network remodeling to perform Gap junction endocytosis. Basic Clin Androl 2023; 33:20. [PMID: 37533006 PMCID: PMC10399049 DOI: 10.1186/s12610-023-00194-y] [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: 12/19/2022] [Accepted: 04/16/2023] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND The endocytosis of Gap junction plaques (GJP) requires cytoskeletal forces to internalize such large membranous structures. Actin, which partners the connexin proteins constituting Gap junctions and is located close to Annular Gap Junctions (AGJ), could be actively involved in this physiological process. RESULTS Electron Microscopy and Light Microscopy images, associated with time-lapse analysis and 3D reconstruction, used at high resolution and enhanced using ImageJ based software analysis, revealed that: i) actin cables, originating from Donor cells, insert on the edge of GJP and contribute to their invagination, giving rise to AGJ, whereas actin cables on the Acceptor cell side of the plaque are not modified; ii) actin cables from the Donor cell are continuous with the actin network present over the entire GJP surface. These actin cables fuse at a single point distant from the plaque, which then detaches itself from the membrane, condensing to form an actin mass during the final internalization process; iii) the Acceptor cell participates in the last step of the endocytic invagination process by forming an annular actin structure known as an actin ring. CONCLUSIONS Together, these data suggest that the endocytosis of GJP is an example of a unique cooperative mechanism between the Donor (the traction of its actin cables) and the Acceptor cells (forming the actin ring).
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Affiliation(s)
- Dominique Segretain
- UMR S1147, Université Paris Descartes, 45 Rue Des Saints-Pères, 75006, Paris, France.
| | - Mathilde Di Marco
- UMR S1147, Université Paris Descartes, 45 Rue Des Saints-Pères, 75006, Paris, France
- Present Address: Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, 75005, Paris, France
| | - Chloé Dufeu
- Faculté de Pharmacie, Université Paris-Saclay, Saclay, France
| | | | - Alain Trubuil
- MaIAGE, INRAE, Université Paris-Saclay, 78352, Jouy-en-Josas, France
| | - Georges Pointis
- INSERM U 1065, Team 5 Physiopathological Control of Germ Cell Proliferation: Genomic and Non-Genomic Mechanisms, University of Nice Sophia-Antipolis, 151 Route Saint-Antoine de Ginestière BP 2 3194, 06204, Nice Cedex 3, France
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Shilpashree PS, Ravi T, Thanuja MY, Anupama C, Ranganath SH, Suresh KV, Srinivas SP. Grading the Severity of Damage to the Perijunctional Actomyosin Ring and Zonula Occludens-1 of the Corneal Endothelium by Ensemble Learning Methods. J Ocul Pharmacol Ther 2023. [PMID: 36930844 DOI: 10.1089/jop.2022.0154] [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: 03/19/2023] Open
Abstract
Purpose: In many epithelia, including the corneal endothelium, intracellular/extracellular stresses break down the perijunctional actomyosin ring (PAMR) and zonula occludens-1 (ZO-1) at the apical junctions. This study aims to grade the severity of damage to PAMR and ZO-1 through machine learning. Methods: Immunocytochemical images of PAMR and ZO-1 were drawn from recent studies on the corneal endothelium subjected to hypothermia and oxidative stress. The images were analyzed for their morphological (e.g., Hu moments) and textural features (based on gray-level co-occurrence matrix [GLCM] and Gabor filters). The extracted features were ranked by SHapley analysis and analysis of variance. Then top features were used to grade the severity of damage using a suite of ensemble classifiers, including random forest, bagging classifier (BC), AdaBoost, extreme gradient boosting, and stacking classifier. Results: A partial set of features from GLCM, along with Hu moments and the number of hexagons, enabled the classification of damage to PAMR into Control, Mild, Moderate, and Severe with the area under the receiver operating characteristics curve (AUC) = 0.92 and F1 score = 0.77 with BC. In contrast, a bank of Gabor filters provided a partial set of features that could be combined with Hu moments, branch length, and sharpness for the classification of ZO-1 images into four levels with AUC = 0.95 and F1 score of 0.8 with BC. Conclusions: We have developed a workflow that enables the stratification of damage to PAMR and ZO-1. The approach can be applied to similar data during drug discovery or pathophysiological studies of epithelia.
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Affiliation(s)
- Palanahalli S Shilpashree
- Department of Electronics and Communication, Siddaganga Institute of Technology (Affiliated to VTU, Belagavi), Tumakuru, India
| | - Tapanmitra Ravi
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - M Y Thanuja
- Department of Chemical Engineering, and Siddaganga Institute of Technology (Affiliated to VTU, Belagavi), Tumakuru, India
| | - Chalimeswamy Anupama
- Department of Biotechnology, Siddaganga Institute of Technology (Affiliated to VTU, Belagavi), Tumakuru, India
| | - Sudhir H Ranganath
- Department of Chemical Engineering, and Siddaganga Institute of Technology (Affiliated to VTU, Belagavi), Tumakuru, India
| | - Kaggere V Suresh
- Department of Electronics and Communication, Siddaganga Institute of Technology (Affiliated to VTU, Belagavi), Tumakuru, India
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TRIM40 is a pathogenic driver of inflammatory bowel disease subverting intestinal barrier integrity. Nat Commun 2023; 14:700. [PMID: 36755029 PMCID: PMC9908899 DOI: 10.1038/s41467-023-36424-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023] Open
Abstract
The cortical actin cytoskeleton plays a critical role in maintaining intestinal epithelial integrity, and the loss of this architecture leads to chronic inflammation, as seen in inflammatory bowel disease (IBD). However, the exact mechanisms underlying aberrant actin remodeling in pathological states remain largely unknown. Here, we show that a subset of patients with IBD exhibits substantially higher levels of tripartite motif-containing protein 40 (TRIM40), a gene that is hardly detectable in healthy individuals. TRIM40 is an E3 ligase that directly targets Rho-associated coiled-coil-containing protein kinase 1 (ROCK1), an essential kinase involved in promoting cell-cell junctions, markedly decreasing the phosphorylation of key signaling factors critical for cortical actin formation and stabilization. This causes failure of the epithelial barrier function, thereby promoting a long-lived inflammatory response. A mutant TRIM40 lacking the RING, B-box, or C-terminal domains has impaired ability to accelerate ROCK1 degradation-driven cortical actin disruption. Accordingly, Trim40-deficient male mice are highly resistant to dextran sulfate sodium (DSS)-induced colitis. Our findings highlight that aberrant upregulation of TRIM40, which is epigenetically silenced under healthy conditions, drives IBD by subverting cortical actin formation and exacerbating epithelial barrier dysfunction.
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The Cytoskeleton in Plant Immunity: Dynamics, Regulation, and Function. Int J Mol Sci 2022; 23:ijms232415553. [PMID: 36555194 PMCID: PMC9779068 DOI: 10.3390/ijms232415553] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
The plant cytoskeleton, consisting of actin filaments and microtubules, is a highly dynamic filamentous framework involved in plant growth, development, and stress responses. Recently, research has demonstrated that the plant cytoskeleton undergoes rapid remodeling upon sensing pathogen attacks, coordinating the formation of microdomain immune complexes, the dynamic and turnover of pattern-recognizing receptors (PRRs), the movement and aggregation of organelles, and the transportation of defense compounds, thus serving as an important platform for responding to pathogen infections. Meanwhile, pathogens produce effectors targeting the cytoskeleton to achieve pathogenicity. Recent findings have uncovered several cytoskeleton-associated proteins mediating cytoskeletal remodeling and defense signaling. Furthermore, the reorganization of the actin cytoskeleton is revealed to further feedback-regulate reactive oxygen species (ROS) production and trigger salicylic acid (SA) signaling, suggesting an extremely complex role of the cytoskeleton in plant immunity. Here, we describe recent advances in understanding the host cytoskeleton dynamics upon sensing pathogens and summarize the effectors that target the cytoskeleton. We highlight advances in the regulation of cytoskeletal remodeling associated with the defense response and assess the important function of the rearrangement of the cytoskeleton in the immune response. Finally, we propose suggestions for future research in this area.
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