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Dean WF, Nawara TJ, Albert RM, Mattheyses AL. OOPS: Object-Oriented Polarization Software for analysis of fluorescence polarization microscopy images. PLoS Comput Biol 2024; 20:e1011723. [PMID: 39133751 PMCID: PMC11341096 DOI: 10.1371/journal.pcbi.1011723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 08/22/2024] [Accepted: 08/02/2024] [Indexed: 08/24/2024] Open
Abstract
Most essential cellular functions are performed by proteins assembled into larger complexes. Fluorescence Polarization Microscopy (FPM) is a powerful technique that goes beyond traditional imaging methods by allowing researchers to measure not only the localization of proteins within cells, but also their orientation or alignment within complexes or cellular structures. FPM can be easily integrated into standard widefield microscopes with the addition of a polarization modulator. However, the extensive image processing and analysis required to interpret the data have limited its widespread adoption. To overcome these challenges and enhance accessibility, we introduce OOPS (Object-Oriented Polarization Software), a MATLAB package for object-based analysis of FPM data. By combining flexible image segmentation and novel object-based analyses with a high-throughput FPM processing pipeline, OOPS empowers researchers to simultaneously study molecular order and orientation in individual biological structures; conduct population assessments based on morphological features, intensity statistics, and FPM measurements; and create publication-quality visualizations, all within a user-friendly graphical interface. Here, we demonstrate the power and versatility of our approach by applying OOPS to punctate and filamentous structures.
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Affiliation(s)
- William F. Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Tomasz J. Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Rose M. Albert
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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2
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Stjepić V, Nakamura M, Hui J, Parkhurst SM. Two Septin complexes mediate actin dynamics during cell wound repair. Cell Rep 2024; 43:114215. [PMID: 38728140 PMCID: PMC11203717 DOI: 10.1016/j.celrep.2024.114215] [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: 11/16/2023] [Revised: 03/18/2024] [Accepted: 04/24/2024] [Indexed: 05/12/2024] Open
Abstract
Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1/Sep2/Pnut and Sep4/Sep5/Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side by side to discretely regulate actomyosin ring dynamics during cell wound repair.
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Affiliation(s)
- Viktor Stjepić
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Justin Hui
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Susan M Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
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3
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Chandler T, Guo M, Su Y, Chen J, Wu Y, Liu J, Agashe A, Fischer RS, Mehta SB, Kumar A, Baskin TI, Jamouillé V, Liu H, Swaminathan V, Nain A, Oldenbourg R, Riviére PL, Shroff H. Three-dimensional spatio-angular fluorescence microscopy with a polarized dual-view inverted selective-plane illumination microscope (pol-diSPIM). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.09.584243. [PMID: 38712306 PMCID: PMC11071302 DOI: 10.1101/2024.03.09.584243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Polarized fluorescence microscopy is a valuable tool for measuring molecular orientations, but techniques for recovering three-dimensional orientations and positions of fluorescent ensembles are limited. We report a polarized dual-view light-sheet system for determining the three-dimensional orientations and diffraction-limited positions of ensembles of fluorescent dipoles that label biological structures, and we share a set of visualization, histogram, and profiling tools for interpreting these positions and orientations. We model our samples, their excitation, and their detection using coarse-grained representations we call orientation distribution functions (ODFs). We apply ODFs to create physics-informed models of image formation with spatio-angular point-spread and transfer functions. We use theory and experiment to conclude that light-sheet tilting is a necessary part of our design for recovering all three-dimensional orientations. We use our system to extend known two-dimensional results to three dimensions in FM1-43-labelled giant unilamellar vesicles, fast-scarlet-labelled cellulose in xylem cells, and phalloidin-labelled actin in U2OS cells. Additionally, we observe phalloidin-labelled actin in mouse fibroblasts grown on grids of labelled nanowires and identify correlations between local actin alignment and global cell-scale orientation, indicating cellular coordination across length scales.
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Affiliation(s)
- Talon Chandler
- CZ Biohub SF, San Francisco, 94158, California, USA
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
| | - Min Guo
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Yijun Su
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, 20147, Virginia, USA
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Yicong Wu
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Junyu Liu
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Atharva Agashe
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, 24061, Virginia, USA
| | - Robert S. Fischer
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, 20892, Maryland, USA
| | - Shalin B. Mehta
- CZ Biohub SF, San Francisco, 94158, California, USA
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Abhishek Kumar
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Tobias I. Baskin
- Biology Department, University of Massachusetts, Amherst, 01003, Maryland, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Valentin Jamouillé
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A 1S6, British Columbia, Canada
| | - Huafeng Liu
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, Zhejiang, China
| | - Vinay Swaminathan
- Department of Clinical Sciences, Lund University, Lund, SE-221 00, Scania, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, SE-221 00, Scania, Sweden
| | - Amrinder Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, 24061, Virginia, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, 24061, Virginia, USA
| | - Rudolf Oldenbourg
- Bell Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Patrick La Riviére
- Department of Radiology, University of Chicago, Chicago, 60637, Illinois, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, 20892, Maryland, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, 20147, Virginia, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, 02543, Massachusetts, USA
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4
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Grupp B, Denkhaus L, Gerhardt S, Vögele M, Johnsson N, Gronemeyer T. The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity. Commun Biol 2024; 7:48. [PMID: 38184752 PMCID: PMC10771490 DOI: 10.1038/s42003-023-05734-w] [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: 07/12/2023] [Accepted: 12/20/2023] [Indexed: 01/08/2024] Open
Abstract
The septins of the yeast Saccharomyces cerevisiae assemble into hetero-octameric rods by alternating interactions between neighboring G-domains or N- and C-termini, respectively. These rods polymerize end to end into apolar filaments, forming a ring beneath the prospective new bud that expands during the cell cycle into an hourglass structure. The hourglass finally splits during cytokinesis into a double ring. Understanding these transitions as well as the plasticity of the higher order assemblies requires a detailed knowledge of the underlying structures. Here we present the first X-ray crystal structure of a tetrameric Shs1-Cdc12-Cdc3-Cdc10 complex at a resolution of 3.2 Å. Close inspection of the NC-interfaces of this and other septin structures reveals a conserved contact motif that is essential for NC-interface integrity of yeast and human septins in vivo and in vitro. Using the tetrameric structure in combination with AlphaFold-Multimer allowed us to propose a model of the octameric septin rod.
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Affiliation(s)
- Benjamin Grupp
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Lukas Denkhaus
- Institute of Biochemistry, Albert-Ludwigs University, Freiburg, Germany
| | - Stefan Gerhardt
- Institute of Biochemistry, Albert-Ludwigs University, Freiburg, Germany
| | - Matthis Vögele
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Nils Johnsson
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Ulm University, Ulm, Germany.
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5
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Stjepić V, Nakamura M, Hui J, Parkhurst SM. Two Septin Complexes Mediate Actin Dynamics During Cell Wound Repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567084. [PMID: 38014090 PMCID: PMC10680708 DOI: 10.1101/2023.11.14.567084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1-Sep2-Pnut and Sep4-Sep5-Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side-by-side to discretely regulate actomyosin ring dynamics during cell wound repair.
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Affiliation(s)
- Viktor Stjepić
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Justin Hui
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Susan M. Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
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6
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Werner B, Yadav S. Phosphoregulation of the septin cytoskeleton in neuronal development and disease. Cytoskeleton (Hoboken) 2023; 80:275-289. [PMID: 36127729 PMCID: PMC10025170 DOI: 10.1002/cm.21728] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/13/2022] [Accepted: 09/12/2022] [Indexed: 11/06/2022]
Abstract
Septins are highly conserved GTP-binding proteins that oligomerize and form higher order structures. The septin cytoskeleton plays an important role in cellular organization, intracellular transport, and cytokinesis. Kinase-mediated phosphorylation of septins regulates various aspects of their function, localization, and dynamics. Septins are enriched in the mammalian nervous system where they contribute to neurodevelopment and neuronal function. Emerging research has implicated aberrant changes in septin cytoskeleton in several human diseases. The mechanisms through which aberrant phosphorylation by kinases contributes to septin dysfunction in neurological disorders are poorly understood and represent an important question for future research with therapeutic implications. This review summarizes the current state of knowledge of the diversity of kinases that interact with and phosphorylate mammalian septins, delineates how phosphoregulation impacts septin dynamics, and describes how aberrant septin phosphorylation contributes to neurological disorders.
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Affiliation(s)
- Bailey Werner
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Smita Yadav
- Department of Pharmacology, University of Washington, Seattle, WA, United States
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7
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Benson A, McMurray M. Simultaneous co-overexpression of Saccharomyces cerevisiae septins Cdc3 and Cdc10 drives pervasive, phospholipid-, and tag-dependent plasma membrane localization. Cytoskeleton (Hoboken) 2023; 80:199-214. [PMID: 37098755 PMCID: PMC10524705 DOI: 10.1002/cm.21762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/29/2023] [Accepted: 04/17/2023] [Indexed: 04/27/2023]
Abstract
Septin proteins contribute to many eukaryotic processes involving cellular membranes. In the budding yeast Saccharomyces cerevisiae, septin hetero-oligomers interact with the plasma membrane (PM) almost exclusively at the future site of cytokinesis. While multiple mechanisms of membrane recruitment have been identified, including direct interactions with specific phospholipids and curvature-sensitive interactions via amphipathic helices, these do not fully explain why yeast septins do not localize all over the inner leaflet of the PM. While engineering an inducible split-yellow fluorescent protein (YFP) system to measure the kinetics of yeast septin complex assembly, we found that ectopic co-overexpression of two tagged septins, Cdc3 and Cdc10, resulted in nearly uniform PM localization, as well as perturbation of endogenous septin function. Septin localization and function in gametogenesis were also perturbed. PM localization required the C-terminal YFP fragment fused to the C terminus of Cdc3, the septin-associated kinases Cla4 and Gin4, and phosphotidylinositol-4,5-bis-phosphate (PI[4,5]P2 ), but not the putative PI(4,5)P2 -binding residues in Cdc3. Endogenous Cdc10 was recruited to the PM, likely contributing to the functional interference. PM-localized septins did not exchange with the cytosolic pool, indicative of stable polymers. These findings provide new clues as to what normally restricts septin localization to specific membranes.
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Affiliation(s)
- Aleyna Benson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Michael McMurray
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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8
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Nakamura M, Hui J, Parkhurst SM. Bending actin filaments: twists of fate. Fac Rev 2023; 12:7. [PMID: 37081903 PMCID: PMC10111394 DOI: 10.12703/r/12-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Abstract
In many cellular contexts, intracellular actomyosin networks must generate directional forces to carry out cellular tasks such as migration and endocytosis, which play important roles during normal developmental processes. A number of different actin binding proteins have been identified that form linear or branched actin, and that regulate these filaments through activities such as bundling, crosslinking, and depolymerization to create a wide variety of functional actin assemblies. The helical nature of actin filaments allows them to better accommodate tensile stresses by untwisting, as well as to bend to great curvatures without breaking. Interestingly, this latter property, the bending of actin filaments, is emerging as an exciting new feature for determining dynamic actin configurations and functions. Indeed, recent studies using in vitro assays have found that proteins including IQGAP, Cofilin, Septins, Anillin, α-Actinin, Fascin, and Myosins-alone or in combination-can influence the bending or curvature of actin filaments. This bending increases the number and types of dynamic assemblies that can be generated, as well as the spectrum of their functions. Intriguingly, in some cases, actin bending creates directionality within a cell, resulting in a chiral cell shape. This actin-dependent cell chirality is highly conserved in vertebrates and invertebrates and is essential for cell migration and breaking L-R symmetry of tissues/organs. Here, we review how different types of actin binding protein can bend actin filaments, induce curved filament geometries, and how they impact on cellular functions.
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Affiliation(s)
- Mitsutoshi Nakamura
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Justin Hui
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
| | - Susan M Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA 98109
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9
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Dean WF, Mattheyses AL. Defining domain-specific orientational order in the desmosomal cadherins. Biophys J 2022; 121:4325-4341. [PMID: 36225113 PMCID: PMC9703042 DOI: 10.1016/j.bpj.2022.10.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 09/12/2022] [Accepted: 10/06/2022] [Indexed: 01/25/2023] Open
Abstract
Desmosomes are large, macromolecular protein assemblies that mechanically couple the intermediate filament cytoskeleton to sites of cadherin-mediated cell adhesion, thereby providing structural integrity to tissues that routinely experience large forces. Proper desmosomal adhesion is necessary for the normal development and maintenance of vertebrate tissues, such as epithelia and cardiac muscle, while dysfunction can lead to severe disease of the heart and skin. Therefore, it is important to understand the relationship between desmosomal adhesion and the architecture of the molecules that form the adhesive interface, the desmosomal cadherins (DCs). However, desmosomes are embedded in two plasma membranes and are linked to the cytoskeletal networks of two cells, imposing extreme difficulty on traditional structural studies of DC architecture, which have yielded conflicting results. Consequently, the relationship between DC architecture and adhesive function remains unclear. To overcome these challenges, we utilized excitation-resolved fluorescence polarization microscopy to quantify the orientational order of the extracellular and intracellular domains of three DC isoforms: desmoglein 2, desmocollin 2, and desmoglein 3. We found that DC ectodomains were significantly more ordered than their cytoplasmic counterparts, indicating a drastic difference in DC architecture between opposing sides of the plasma membrane. This difference was conserved among all DCs tested, suggesting that it may be an important feature of desmosomal architecture. Moreover, our findings suggest that the organization of DC ectodomains is predominantly the result of extracellular adhesive interactions. We employed azimuthal orientation mapping to show that DC ectodomains are arranged with rotational symmetry about the membrane normal. Finally, we performed a series of mathematical simulations to test the feasibility of a recently proposed antiparallel arrangement of DC ectodomains, finding that it is supported by our experimental data. Importantly, the strategies employed here have the potential to elucidate molecular mechanisms for diseases that result from defective desmosome architecture.
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Affiliation(s)
- William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama.
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10
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Ivanov IE, Yeh LH, Perez-Bermejo JA, Byrum JR, Kim JYS, Leonetti MD, Mehta SB. Correlative imaging of the spatio-angular dynamics of biological systems with multimodal instant polarization microscope. BIOMEDICAL OPTICS EXPRESS 2022; 13:3102-3119. [PMID: 35774313 PMCID: PMC9203109 DOI: 10.1364/boe.455770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 05/29/2023]
Abstract
The spatial and angular organization of biological macromolecules is a key determinant, as well as informative readout, of their function. Correlative imaging of the dynamic spatio-angular architecture of cells and organelles is valuable, but remains challenging with current methods. Correlative imaging of spatio-angular dynamics requires fast polarization-, depth-, and wavelength-diverse measurement of intrinsic optical properties and fluorescent labels. We report a multimodal instant polarization microscope (miPolScope) that combines a broadband polarization-resolved detector, automation, and reconstruction algorithms to enable label-free imaging of phase, retardance, and orientation, multiplexed with fluorescence imaging of concentration, anisotropy, and orientation of molecules at diffraction-limited resolution and high speed. miPolScope enabled multimodal imaging of myofibril architecture and contractile activity of beating cardiomyocytes, cell and organelle architecture of live HEK293T and U2OS cells, and density and anisotropy of white and grey matter of mouse brain tissue across the visible spectrum. We anticipate these developments in joint quantitative imaging of density and anisotropy to enable new studies in tissue pathology, mechanobiology, and imaging-based screens.
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Affiliation(s)
- Ivan E. Ivanov
- Chan Zuckerberg Biohub, 499 Illinois St, San Francisco, CA 94158, USA
| | - Li-Hao Yeh
- Chan Zuckerberg Biohub, 499 Illinois St, San Francisco, CA 94158, USA
| | | | - Janie R. Byrum
- Chan Zuckerberg Biohub, 499 Illinois St, San Francisco, CA 94158, USA
| | - James Y. S. Kim
- Chan Zuckerberg Biohub, 499 Illinois St, San Francisco, CA 94158, USA
| | | | - Shalin B. Mehta
- Chan Zuckerberg Biohub, 499 Illinois St, San Francisco, CA 94158, USA
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11
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Arbizzani F, Mavrakis M, Hoya M, Ribas JC, Brasselet S, Paoletti A, Rincon SA. Septin filament compaction into rings requires the anillin Mid2 and contractile ring constriction. Cell Rep 2022; 39:110722. [PMID: 35443188 DOI: 10.1016/j.celrep.2022.110722] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 02/10/2022] [Accepted: 03/30/2022] [Indexed: 11/19/2022] Open
Abstract
Septin filaments assemble into high-order molecular structures that associate with membranes, acting as diffusion barriers and scaffold proteins crucial for many cellular processes. How septin filaments organize in such structures is still not understood. Here, we used fission yeast to explore septin filament organization during cell division and its cell cycle regulation. Live-imaging and polarization microscopy analysis uncovered that septin filaments are initially recruited as a diffuse meshwork surrounding the acto-myosin contractile ring (CR) in anaphase, which undergoes compaction into two rings when CR constriction is initiated. We found that the anillin-like protein Mid2 is necessary to promote this compaction step, possibly acting as a bundler for septin filaments. Moreover, Mid2-driven septin compaction requires inputs from the septation initiation network as well as CR constriction and the β(1,3)-glucan synthase Bgs1. This work highlights that anillin-mediated septin ring assembly is under strict cell cycle control.
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Affiliation(s)
| | - Manos Mavrakis
- Aix Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, 13013 Marseille, France
| | - Marta Hoya
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Sophie Brasselet
- Aix Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, 13013 Marseille, France
| | - Anne Paoletti
- Institut Curie, PSL University, CNRS UMR 144, 75005 Paris, France.
| | - Sergio A Rincon
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, 37007 Salamanca, Spain.
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12
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Role of the anillin-like protein in growth of Cryptococcus neoformans at human host temperature. Fungal Genet Biol 2022; 160:103697. [DOI: 10.1016/j.fgb.2022.103697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 11/23/2022]
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13
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Moyano-Rodríguez Y, Vaquero D, Vilalta-Castany O, Foltman M, Sanchez-Diaz A, Queralt E. PP2A-Cdc55 phosphatase regulates actomyosin ring contraction and septum formation during cytokinesis. Cell Mol Life Sci 2022; 79:165. [PMID: 35230542 PMCID: PMC8888506 DOI: 10.1007/s00018-022-04209-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/03/2022]
Abstract
Eukaryotic cells divide and separate all their components after chromosome segregation by a process called cytokinesis to complete cell division. Cytokinesis is highly regulated by the recruitment of the components to the division site and through post-translational modifications such as phosphorylations. The budding yeast mitotic kinases Cdc28-Clb2, Cdc5, and Dbf2-Mob1 phosphorylate several cytokinetic proteins contributing to the regulation of cytokinesis. The PP2A-Cdc55 phosphatase regulates mitosis counteracting Cdk1- and Cdc5-dependent phosphorylation. This prompted us to propose that PP2A-Cdc55 could also be counteracting the mitotic kinases during cytokinesis. Here we show that in the absence of Cdc55, AMR contraction and the primary septum formation occur asymmetrically to one side of the bud neck supporting a role for PP2A-Cdc55 in cytokinesis regulation. In addition, by in vivo and in vitro assays, we show that PP2A-Cdc55 dephosphorylates the chitin synthase II (Chs2 in budding yeast) a component of the Ingression Progression Complexes (IPCs) involved in cytokinesis. Interestingly, the non-phosphorylable version of Chs2 rescues the asymmetric AMR contraction and the defective septa formation observed in cdc55∆ mutant cells. Therefore, timely dephosphorylation of the Chs2 by PP2A-Cdc55 is crucial for proper actomyosin ring contraction. These findings reveal a new mechanism of cytokinesis regulation by the PP2A-Cdc55 phosphatase and extend our knowledge of the involvement of multiple phosphatases during cytokinesis.
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Affiliation(s)
- Yolanda Moyano-Rodríguez
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - David Vaquero
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain.,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain
| | - Odena Vilalta-Castany
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Magdalena Foltman
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Alberto Sanchez-Diaz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Ethel Queralt
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain. .,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain.
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14
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Marquardt J, Chen X, Bi E. Septin Assembly and Remodeling at the Cell Division Site During the Cell Cycle. Front Cell Dev Biol 2021; 9:793920. [PMID: 34901034 PMCID: PMC8656427 DOI: 10.3389/fcell.2021.793920] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
The septin family of proteins can assemble into filaments that further organize into different higher order structures to perform a variety of different functions in different cell types and organisms. In the budding yeast Saccharomyces cerevisiae, the septins localize to the presumptive bud site as a cortical ring prior to bud emergence, expand into an hourglass at the bud neck (cell division site) during bud growth, and finally “split” into a double ring sandwiching the cell division machinery during cytokinesis. While much work has been done to understand the functions and molecular makeups of these structures, the mechanisms underlying the transitions from one structure to another have largely remained elusive. Recent studies involving advanced imaging and in vitro reconstitution have begun to reveal the vast complexity involved in the regulation of these structural transitions, which defines the focus of discussion in this mini-review.
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Affiliation(s)
- Joseph Marquardt
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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15
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Blanchard A, Combs JD, Brockman JM, Kellner AV, Glazier R, Su H, Bender RL, Bazrafshan AS, Chen W, Quach ME, Li R, Mattheyses AL, Salaita K. Turn-key mapping of cell receptor force orientation and magnitude using a commercial structured illumination microscope. Nat Commun 2021; 12:4693. [PMID: 34344862 PMCID: PMC8333341 DOI: 10.1038/s41467-021-24602-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 06/22/2021] [Indexed: 02/07/2023] Open
Abstract
Many cellular processes, including cell division, development, and cell migration require spatially and temporally coordinated forces transduced by cell-surface receptors. Nucleic acid-based molecular tension probes allow one to visualize the piconewton (pN) forces applied by these receptors. Building on this technology, we recently developed molecular force microscopy (MFM) which uses fluorescence polarization to map receptor force orientation with diffraction-limited resolution (~250 nm). Here, we show that structured illumination microscopy (SIM), a super-resolution technique, can be used to perform super-resolution MFM. Using SIM-MFM, we generate the highest resolution maps of both the magnitude and orientation of the pN traction forces applied by cells. We apply SIM-MFM to map platelet and fibroblast integrin forces, as well as T cell receptor forces. Using SIM-MFM, we show that platelet traction force alignment occurs on a longer timescale than adhesion. Importantly, SIM-MFM can be implemented on any standard SIM microscope without hardware modifications.
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Affiliation(s)
- Aaron Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - J Dale Combs
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Joshua M Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Anna V Kellner
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Roxanne Glazier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Hanquan Su
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | | | | | - Wenchun Chen
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - M Edward Quach
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Department of Chemistry, Emory University, Atlanta, GA, USA.
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16
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Woods BL, Cannon KS, Vogt EJD, Crutchley JM, Gladfelter AS. Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling. Mol Biol Cell 2021; 32:br5. [PMID: 34319771 PMCID: PMC8684760 DOI: 10.1091/mbc.e20-05-0303] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The curvature of the membrane defines cell shape. Septins are GTP-binding proteins that assemble into heteromeric complexes and polymerize into filaments at areas of micron-scale membrane curvature. An amphipathic helix (AH) domain within the septin complex is necessary and sufficient for septins to preferentially assemble onto micron-scale curvature. Here we report that the nonessential fungal septin, Shs1, also has an AH domain capable of recognizing membrane curvature. In a septin mutant strain lacking a fully functional Cdc12 AH domain (cdc12-6), the C-terminal extension of Shs1, containing an AH domain, becomes essential. Additionally, we find that the Cdc12 AH domain is important for regulating septin filament bundling, suggesting septin AH domains have multiple, distinct functions and that bundling and membrane binding may be coordinately controlled.
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Affiliation(s)
- Benjamin L Woods
- Biology Department, University of North Carolina, Chapel Hill, NC 27599
| | - Kevin S Cannon
- Biology Department, University of North Carolina, Chapel Hill, NC 27599
| | - Ellysa J D Vogt
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599
| | - John M Crutchley
- Biology Department, University of North Carolina, Chapel Hill, NC 27599
| | - Amy S Gladfelter
- Biology Department, University of North Carolina, Chapel Hill, NC 27599.,Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599.,Marine Biological Laboratory, Woods Hole, MA 02543
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17
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Abstract
In bacteria, a condensed structure of FtsZ (Z-ring) recruits cell division machinery at the midcell, and Z-ring formation is discouraged over the chromosome by a poorly understood phenomenon called nucleoid occlusion. In B. subtilis, nucleoid occlusion has been reported to be mediated, at least in part, by the DNA-membrane bridging protein, Noc. Bacteria that divide by binary fission form FtsZ rings at the geometric midpoint of the cell between the bulk of the replicated nucleoids. In Bacillus subtilis, the DNA- and membrane-binding Noc protein is thought to participate in nucleoid occlusion by preventing FtsZ rings from forming over the chromosome. To explore the role of Noc, we used time-lapse fluorescence microscopy to monitor FtsZ and the nucleoid of cells growing in microfluidic channels. Our data show that Noc does not prevent de novo FtsZ ring formation over the chromosome nor does Noc control cell division site selection. Instead, Noc corrals FtsZ at the cytokinetic ring and reduces migration of protofilaments over the chromosome to the future site of cell division. Moreover, we show that FtsZ protofilaments travel due to a local reduction in ZapA association, and the diffuse FtsZ rings observed in the Noc mutant can be suppressed by ZapA overexpression. Thus, Noc sterically hinders FtsZ migration away from the Z-ring during cytokinesis and retains FtsZ at the postdivisional polar site for full disassembly by the Min system.
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18
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Okada H, MacTaggart B, Ohya Y, Bi E. The kinetic landscape and interplay of protein networks in cytokinesis. iScience 2021; 24:101917. [PMID: 33392480 PMCID: PMC7773586 DOI: 10.1016/j.isci.2020.101917] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/08/2022] Open
Abstract
Cytokinesis is executed by protein networks organized into functional modules. Individual proteins within each module have been characterized to various degrees. However, the collective behavior and interplay of the modules remain poorly understood. In this study, we conducted quantitative time-lapse imaging to analyze the accumulation kinetics of more than 20 proteins from different modules of cytokinesis in budding yeast. This analysis has led to a comprehensive picture of the kinetic landscape of cytokinesis, from actomyosin ring (AMR) assembly to cell separation. It revealed that the AMR undergoes biphasic constriction and that the switch between the constriction phases is likely triggered by AMR maturation and primary septum formation. This analysis also provided further insights into the functions of actin filaments and the transglutaminase-like protein Cyk3 in cytokinesis and, in addition, defined Kre6 as the likely enzyme that catalyzes β-1,6-glucan synthesis to drive cell wall maturation during cell growth and division. Cytokinesis is executed by protein modules each with a unique kinetic signature Actomyosin ring constricts in a biphasic manner that is elaborately regulated The transglutaminase-like domain in Cyk3 plays a dual role in cytokinesis Kre6 catalyzes β-1,6-glucan synthesis at the cell surface during growth and division
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Affiliation(s)
- Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Brittany MacTaggart
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Yoshikazu Ohya
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
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19
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Takagi J, Cho C, Duvalyan A, Yan Y, Halloran M, Hanson-Smith V, Thorner J, Finnigan GC. Reconstructed evolutionary history of the yeast septins Cdc11 and Shs1. G3-GENES GENOMES GENETICS 2021; 11:6025175. [PMID: 33561226 PMCID: PMC7849910 DOI: 10.1093/g3journal/jkaa006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/13/2020] [Indexed: 11/21/2022]
Abstract
Septins are GTP-binding proteins conserved across metazoans. They can polymerize into extended filaments and, hence, are considered a component of the cytoskeleton. The number of individual septins varies across the tree of life—yeast (Saccharomyces cerevisiae) has seven distinct subunits, a nematode (Caenorhabditis elegans) has two, and humans have 13. However, the overall geometric unit (an apolar hetero-octameric protomer and filaments assembled there from) has been conserved. To understand septin evolutionary variation, we focused on a related pair of yeast subunits (Cdc11 and Shs1) that appear to have arisen from gene duplication within the fungal clade. Either Cdc11 or Shs1 occupies the terminal position within a hetero-octamer, yet Cdc11 is essential for septin function and cell viability, whereas Shs1 is not. To discern the molecular basis of this divergence, we utilized ancestral gene reconstruction to predict, synthesize, and experimentally examine the most recent common ancestor (“Anc.11-S”) of Cdc11 and Shs1. Anc.11-S was able to occupy the terminal position within an octamer, just like the modern subunits. Although Anc.11-S supplied many of the known functions of Cdc11, it was unable to replace the distinct function(s) of Shs1. To further evaluate the history of Shs1, additional intermediates along a proposed trajectory from Anc.11-S to yeast Shs1 were generated and tested. We demonstrate that multiple events contributed to the current properties of Shs1: (1) loss of Shs1–Shs1 self-association early after duplication, (2) co-evolution of heterotypic Cdc11–Shs1 interaction between neighboring hetero-octamers, and (3) eventual repurposing and acquisition of novel function(s) for its C-terminal extension domain. Thus, a pair of duplicated proteins, despite constraints imposed by assembly into a highly conserved multi-subunit structure, could evolve new functionality via a complex evolutionary pathway.
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Affiliation(s)
- Julie Takagi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA
| | - Christina Cho
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA
| | - Angela Duvalyan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA
| | - Yao Yan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Megan Halloran
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Victor Hanson-Smith
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA
| | - Jeremy Thorner
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3202, USA
| | - Gregory C Finnigan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
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20
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Farkašovský M. Septin architecture and function in budding yeast. Biol Chem 2020; 401:903-919. [PMID: 31913844 DOI: 10.1515/hsz-2019-0401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/28/2019] [Indexed: 01/22/2023]
Abstract
The septins constitute a conserved family of guanosine phosphate-binding and filament-forming proteins widespread across eukaryotic species. Septins appear to have two principal functions. One is to form a cortical diffusion barrier, like the septin collar at the bud neck of Saccharomyces cerevisiae, which prevents movement of membrane-associated proteins between the mother and daughter cells. The second is to serve as a polymeric scaffold for recruiting the proteins required for critical cellular processes to particular subcellular areas. In the last decade, structural information about the different levels of septin organization has appeared, but crucial structural determinants and factors responsible for septin assembly remain largely unknown. This review highlights recent findings on the architecture and function of septins and their remodeling with an emphasis on mitotically dividing budding yeasts.
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Affiliation(s)
- Marian Farkašovský
- Department of Biochemistry and Protein Structure, Institute of Molecular Biology SAS, Dubravska cesta 21, 84551 Bratislava, Slovak Republic
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21
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Blanchard AT, Brockman JM, Salaita K, Mattheyses AL. Variable incidence angle linear dichroism (VALiD): a technique for unique 3D orientation measurement of fluorescent ensembles. OPTICS EXPRESS 2020; 28:10039-10061. [PMID: 32225599 PMCID: PMC7340377 DOI: 10.1364/oe.381676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 06/02/2023]
Abstract
A fundamental challenge with fluorophore orientation measurement is degeneracy, which is the inability to distinguish between multiple unique fluorophore orientations. Techniques exist for the non-degenerate measurement of the orientations of single, static fluorophores. However, such techniques are unsuitable for densely labeled and/or dynamic samples common to biological research. Accordingly, a rapid, widefield microscopy technique that can measure orientation parameters for ensembles of fluorophores in a non-degenerate manner is desirable. We propose that exciting samples with polarized light and multiple incidence angles could enable such a technique. We use Monte Carlo simulations to validate this approach for specific axially symmetric ensembles of fluorophores and obtain optimal experimental parameters for its future implementation.
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Affiliation(s)
- Aaron T. Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Joshua M. Brockman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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22
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Chen X, Wang K, Svitkina T, Bi E. Critical Roles of a RhoGEF-Anillin Module in Septin Architectural Remodeling during Cytokinesis. Curr Biol 2020; 30:1477-1490.e3. [PMID: 32197082 DOI: 10.1016/j.cub.2020.02.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/23/2019] [Accepted: 02/10/2020] [Indexed: 12/24/2022]
Abstract
How septin architecture is remodeled from an hourglass to a double ring during cytokinesis in fungal and animal cells remains unknown. Here, we show that during the hourglass-to-double-ring transition in budding yeast, septins acquire a "zonal architecture" in which paired septin filaments that are organized along the mother-bud axis associate with circumferential single septin filaments, the Rho guanine-nucleotide-exchange factor (RhoGEF) Bud3, and the anillin-like protein Bud4 exclusively at the outer zones and with myosin-II filaments in the middle zone. Deletion of Bud3 or its Bud4-interacting domain, but not its RhoGEF domain, leads to a complete loss of the single filaments, whereas deletion of Bud4 or its Bud3-interacting domain destabilizes the transitional hourglass, especially at the mother side, with partial loss of both filament types. Deletion of Bud3 and Bud4 together further weakens the transitional structure and abolishes the double ring formation while causing no obvious defect in actomyosin ring constriction. This and further analyses suggest that Bud3 stabilizes the single filaments, whereas Bud4 strengthens the interaction between the paired and single filaments at the outer zones of the transitional hourglass, as well as in the double ring. This study reveals a striking zonal architecture for the transitional hourglass that pre-patterns two cytokinetic structures-a septin double ring and an actomyosin ring-and also defines the essential roles of a RhoGEF-anillin module in septin architectural remodeling during cytokinesis at the filament level.
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Affiliation(s)
- Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
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23
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Wiedemann C, Amann B, Degroote RL, Witte T, Deeg CA. Aberrant Migratory Behavior of Immune Cells in Recurrent Autoimmune Uveitis in Horses. Front Cell Dev Biol 2020; 8:101. [PMID: 32211402 PMCID: PMC7076317 DOI: 10.3389/fcell.2020.00101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/07/2020] [Indexed: 11/17/2022] Open
Abstract
The participating signals and structures that enable primary immune cells migrating within dense tissues are not completely revealed until now. Especially in autoimmune diseases, mostly unknown mechanisms facilitate autoreactive immune cells to migrate to endogenous tissues, infiltrating and harming organ-specific structures. In order to gain deeper insights into the migratory behavior of primary autoreactive immune cells, we examined peripheral blood-derived lymphocytes (PBLs) of horses with equine recurrent uveitis (ERU), a spontaneous animal model for autoimmune uveitis in humans. In this study, we used a three-dimensional collagen I hydrogel matrix and monitored live-cell migration of primary lymphocytes as a reaction to different chemoattractants such as fetal calf serum (FCS), cytokines interleukin-4 (IL-4), and interferon-γ (IFN-γ), and a specific uveitis autoantigen, cellular retinaldehyde binding protein (CRALBP). Through these experiments, we uncovered distinct differences between PBLs from ERU cases and PBLs from healthy animals, with significantly higher cell motility, cell speed, and straightness during migration of PBLs from ERU horses. Furthermore, we emphasized the significance of expression levels and cellular localization of septin 7, a membrane-interacting protein with decreased abundance in PBLs of autoimmune cases. To underline the importance of septin 7 expression changes and the possible contribution to migratory behavior in autoreactive immune cells, we used forchlorfenuron (FCF) as a reversible inhibitor of septin structures. FCF-treated cells showed more directed migration through dense tissue and revealed aberrant septin 7 and F-actin structures along with different protein distribution and translocalization of the latter, uncovered by immunochemistry. Hence, we propose that septin 7 and interacting molecules play a pivotal role in the organization and regulation of cell shaping and migration. With our findings, we contribute to gaining deeper insights into the migratory behavior and septin 7-dependent cytoskeletal reorganization of immune cells in organ-specific autoimmune diseases.
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Affiliation(s)
- Carmen Wiedemann
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Barbara Amann
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Roxane L Degroote
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Tanja Witte
- Faculty of Veterinary Medicine, Equine Hospital, LMU Munich, Munich, Germany
| | - Cornelia A Deeg
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
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24
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He H, Li J, Xu M, Kan Z, Gao Y, Yuan C. Expression of septin 2 and association with clinicopathological parameters in colorectal cancer. Oncol Lett 2019; 18:2376-2383. [PMID: 31402940 PMCID: PMC6676678 DOI: 10.3892/ol.2019.10528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/07/2019] [Indexed: 12/16/2022] Open
Abstract
Septin 2 (SEPT2) is a tumor-related gene belonging to the SEPT family that affects the cellular processes of hepatoma carcinoma cells, glioblastoma cells and mesangial cells and is highly expressed in breast cancer, biliary tract cancer and acute myeloid leukemia. Colorectal cancer (CRC) is the third most common type of malignancy in humans. In the present study, Oncomine database was used to compare the expression pattern of SEPT2 mRNA between CRC and normal tissues. Additionally, protein expression in 90 pairs of CRC and paracancerous tissues was analyzed by western blotting and immunohistochemistry (IHC). The results showed that SEPT2 was highly expressed in CRC tissues at the mRNA and protein levels. SEPT2 expression quantified by IHC was associated with lymph node metastasis, the degree of differentiation and TNM staging. Increased SEPT2 wass associated with reduced overall survival (OS) according to Kaplan-Meier analysis. COX proportional hazard analysis indicated that SEPT2 was an independent factor that influenced the OS of patients with CRC. Therefore, SEPT2 was associated with the occurrence, progression and prognosis of CRC and thus, may be a marker and prognostic indicator of CRC.
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Affiliation(s)
- Haoyu He
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Junjun Li
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Meng Xu
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Ziliang Kan
- Graduate School, Singapore Management University, Singapore 178903, Republic of Singapore
| | - Yang Gao
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Caijun Yuan
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
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25
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CHANDLER TALON, SHROFF HARI, OLDENBOURG RUDOLF, LA RIVIÈRE PATRICK. Spatio-angular fluorescence microscopy I. Basic theory. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:1334-1345. [PMID: 31503559 PMCID: PMC7045726 DOI: 10.1364/josaa.36.001334] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/07/2019] [Indexed: 05/22/2023]
Abstract
We introduce the basic elements of a spatio-angular theory of fluorescence microscopy, providing a unified framework for analyzing systems that image single fluorescent dipoles and ensembles of overlapping dipoles that label biological molecules. We model an aplanatic microscope imaging an ensemble of fluorescent dipoles as a linear Hilbert-space operator, and we show that the operator takes a particularly convenient form when expressed in a basis of complex exponentials and spherical harmonics-a form we call the dipole spatio-angular transfer function. We discuss the implications of our analysis for all quantitative fluorescence microscopy studies and lay out a path toward a complete theory.
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Affiliation(s)
- TALON CHANDLER
- University of Chicago, Department of Radiology, Chicago, Illinois 60637, USA
| | - HARI SHROFF
- Section on High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, USA
- Marine Biological Laboratory, Bell Center, Woods Hole, Massachusetts 02543, USA
| | - RUDOLF OLDENBOURG
- Marine Biological Laboratory, Bell Center, Woods Hole, Massachusetts 02543, USA
| | - PATRICK LA RIVIÈRE
- University of Chicago, Department of Radiology, Chicago, Illinois 60637, USA
- Marine Biological Laboratory, Bell Center, Woods Hole, Massachusetts 02543, USA
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26
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Septin6 regulates cell growth and casein synthesis in dairy cow mammary epithelial cells via mTORC1 pathway. J DAIRY RES 2019; 86:181-187. [PMID: 31122298 DOI: 10.1017/s0022029919000268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
This research paper addresses the hypothesis that Septin6 is a key regulatory factor influencing amino acid (AA)-mediated cell growth and casein synthesis in dairy cow mammary epithelial cells (DCMECs). DCMECs were treated with absence of AA (AA-), restricted concentrations of AA (AAr) or normal concentrations of AA (AA+) for 24 h. Cell growth, expression of CSN2 and Septin6 were increased in response to AA supply. Overexpressing or inhibiting Septin6 demonstrated that cell growth, expression of CSN2, mTOR, p-mTOR, S6K1 and p-S6K1 were up-regulated by Septin6. Furthermore, overexpressing or inhibiting mTOR demonstrated that the increase in cell growth and expression of CSN2 in response to Septin6 overexpression were inhibited by mTOR inhibition, and vice versa. Our hypothesis was supported; we were able to show that Septin6 is an important positive factor for cell growth and casein synthesis, it up-regulates AA-mediated cell growth and casein synthesis through activating mTORC1 pathway in DCMECs.
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Marquardt J, Chen X, Bi E. Architecture, remodeling, and functions of the septin cytoskeleton. Cytoskeleton (Hoboken) 2018; 76:7-14. [PMID: 29979831 DOI: 10.1002/cm.21475] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/05/2018] [Accepted: 06/22/2018] [Indexed: 01/22/2023]
Abstract
The septin family of proteins has fascinated cell biologists for decades due to the elaborate architecture they adopt in different eukaryotic cells. Whether they exist as rings, collars, or gauzes in different cell types and at different times in the cell cycle illustrates a complex series of regulation in structure. While the organization of different septin structures at the cortex of different cell types during the cell cycle has been described to various degrees, the exact structure and regulation at the filament level are still largely unknown. Recent advances in fluorescent and electron microscopy, as well as work in septin biochemistry, have allowed new insights into the aspects of septin architecture, remodeling, and function in many cell types. This mini-review highlights many of the recent findings with an emphasis on the budding yeast model.
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Affiliation(s)
- Joseph Marquardt
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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Orellana-Muñoz S, Dueñas-Santero E, Arnáiz-Pita Y, Del Rey F, Correa-Bordes J, Vázquez de Aldana CR. The anillin-related Int1 protein and the Sep7 septin collaborate to maintain cellular ploidy in Candida albicans. Sci Rep 2018; 8:2257. [PMID: 29396461 PMCID: PMC5797091 DOI: 10.1038/s41598-018-20249-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/15/2018] [Indexed: 11/13/2022] Open
Abstract
Variation in cell ploidy is a common feature of Candida albicans clinical isolates that are resistant to the antifungal drug fluconazole. Here, we report that the anillin-related protein Int1 interacts with septins for coupling cytokinesis with nuclear segregation. Loss of Int1 results in a rapid disassembly of duplicated septin rings from the bud neck at the onset of actomyosin ring contraction. Strikingly, this has no major impact on cytokinesis and septum formation. However, Int1 genetically interacts with the Sep7 septin, maintaining the diffusion barrier at the bud neck and guarantying a faithful nuclear segregation. Indeed, int1ΔΔ sep7ΔΔ mutant cells, in contrast to int1ΔΔ cdc10ΔΔ, undergo a premature activation of mitotic exit prior to the alignment of the mitotic spindle with the division axis, producing large multinucleated cells. Some of these multinucleated cells arise from trimeras similar to those observed upon fluconazole exposure. Finally, the defects in nuclear segregation could be in part due to the inability to maintain the Lte1 mitotic exit activator at the cortex of the daughter cell. These results suggest that Int1 and Sep7 play a role in maintaining genome stability by acting as a diffusion barrier for Lte1.
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Affiliation(s)
- Sara Orellana-Muñoz
- Instituto de Biología Funcional y Genómica, IBFG-CSIC. Universidad de Salamanca, Salamanca, Spain
| | | | - Yolanda Arnáiz-Pita
- Instituto de Biología Funcional y Genómica, IBFG-CSIC. Universidad de Salamanca, Salamanca, Spain
| | - Francisco Del Rey
- Instituto de Biología Funcional y Genómica, IBFG-CSIC. Universidad de Salamanca, Salamanca, Spain
| | - Jaime Correa-Bordes
- Departamento de Ciencias Biomédicas, Universidad de Extremadura, Badajoz, Spain
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Gupta DK, Du J, Kamranvar SA, Johansson S. Tension-induced cytokinetic abscission in human fibroblasts. Oncotarget 2018; 9:8999-9009. [PMID: 29507669 PMCID: PMC5823655 DOI: 10.18632/oncotarget.24016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 12/29/2017] [Indexed: 12/31/2022] Open
Abstract
Previous studies have shown that cytokinetic abscission at the end of mitosis is executed by the ESCRT machinery in mammalian cells, and that the process is dependent on adhesion-induced integrin signalling via a FAK-PLK1-CEP55-TSG101/Alix-CHMP4B pathway. The present study identified an alternative abscission mechanism driven by mechanical force. In the absence of integrin signals (non-adherent conditions), cytokinesis in non-transformed human fibroblasts proceeds to CEP55 accumulation at the midbody, but after prolonged time (>3 hours) the major midbody components Aurora B, MKLP1 and CEP55 were no longer detected in the area. Upon adhesion to fibronectin, such cells were able to complete abscission without re-appearance of midbody proteins. Live-cell imaging revealed that re-plating on stiff fibronectin matrix (64 KPa) allowed >95% of the cells to complete abscission within 9 hours while the corresponding number was 40% on soft fibronectin matrix (0.5 KPa). The cells re-plated on poly-L-lysine were not able to generate tension and did not divide. Thus, mechanical tension can cause cytokinetic abscission by stretching of the intercellular bridge between the two daughter cells until it eventually ruptures without the involvement of ESCRT complexes. Importantly, regression of the cleavage furrow and formation of bi-nucleated cells did not occur in most of the suspension-treated mitotic cells after re-plating on fibronectin. Septin, which stabilizes the membrane associated with the midbody, was found to remain along the ingressed membrane, suggesting that this filament system maintains the membrane bridge although the midbody had dissolved, thereby preventing regression and allowing tension to act on the narrow intercellular bridge.
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Affiliation(s)
- Deepesh Kumar Gupta
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Jian Du
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Uppsala, Sweden.,First Hospital of Jilin University, Changchun, Jilin, China
| | - Siamak A Kamranvar
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Staffan Johansson
- Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Uppsala, Sweden
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Chandler T, Mehta S, Shroff H, Oldenbourg R, La Rivière PJ. Single-fluorophore orientation determination with multiview polarized illumination: modeling and microscope design. OPTICS EXPRESS 2017; 25:31309-31325. [PMID: 29245807 PMCID: PMC5941992 DOI: 10.1364/oe.25.031309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/13/2017] [Accepted: 11/23/2017] [Indexed: 06/02/2023]
Abstract
We investigate the use of polarized illumination in multiview microscopes for determining the orientation of single-molecule fluorescence transition dipoles. First, we relate the orientation of single dipoles to measurable intensities in multiview microscopes and develop an information-theoretic metric-the solid-angle uncertainty-to compare the ability of multiview microscopes to estimate the orientation of single dipoles. Next, we compare a broad class of microscopes using this metric-single- and dual-view microscopes with varying illumination polarization, illumination numerical aperture (NA), detection NA, obliquity, asymmetry, and exposure. We find that multi-view microscopes can measure all dipole orientations, while the orientations measurable with single-view microscopes is halved because of symmetries in the detection process. We also find that choosing a small illumination NA and a large detection NA are good design choices, that multiview microscopes can benefit from oblique illumination and detection, and that asymmetric NA microscopes can benefit from exposure asymmetry.
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Affiliation(s)
- Talon Chandler
- University of Chicago, Department of Radiology, Chicago, Illinois 60637,
USA
| | - Shalin Mehta
- University of Chicago, Department of Radiology, Chicago, Illinois 60637,
USA
- Marine Biological Laboratory, Bell Center, Woods Hole, Massachusetts 02543,
USA
- (present address) Chan Zuckerberg Biohub, San Francisco, California 94158,
USA
| | - Hari Shroff
- Section on High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892,
USA
- Marine Biological Laboratory, Whitman Center, Woods Hole, Massachusetts 02543,
USA
| | - Rudolf Oldenbourg
- Marine Biological Laboratory, Bell Center, Woods Hole, Massachusetts 02543,
USA
- Brown University, Department of Physics, Providence, Rhode Island 02912,
USA
| | - Patrick J. La Rivière
- University of Chicago, Department of Radiology, Chicago, Illinois 60637,
USA
- Marine Biological Laboratory, Whitman Center, Woods Hole, Massachusetts 02543,
USA
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