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Shubhrasmita Sahu S, Sarkar P, Chattopadhyay A. Quantitation of F-actin in cytoskeletal reorganization: Context, methodology and implications. Methods 2024; 230:44-58. [PMID: 39074540 DOI: 10.1016/j.ymeth.2024.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/08/2024] [Accepted: 07/17/2024] [Indexed: 07/31/2024] Open
Abstract
The actin cytoskeleton is involved in a large number of cellular signaling events in addition to providing structural integrity to the cell. Actin polymerization is a key event during cellular signaling. Although the role of actin cytoskeleton in cellular processes such as trafficking and motility has been extensively studied, the reorganization of the actin cytoskeleton upon signaling has been rarely explored due to lack of suitable assays. Keeping in mind this lacuna, we developed a confocal microscopy based approach that relies on high magnification imaging of cellular F-actin, followed by image reconstruction using commercially available software. In this review, we discuss the context and relevance of actin quantitation, followed by a detailed hands-on approach of the methodology involved with specific points on troubleshooting and useful precautions. In the latter part of the review, we elucidate the method by discussing applications of actin quantitation from our work in several important problems in contemporary membrane biology ranging from pathogen entry into host cells, to GPCR signaling and membrane-cytoskeleton interaction. We envision that future discovery of cell-permeable novel fluorescent probes, in combination with genetically encoded actin-binding reporters, would allow real-time visualization of actin cytoskeleton dynamics to gain deeper insights into active cellular processes in health and disease.
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Affiliation(s)
- Subhashree Shubhrasmita Sahu
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Department of Biochemistry, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Amitabha Chattopadhyay
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India.
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2
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Xie C, Chen G, Li M, Huang P, Chen Z, Lei K, Li D, Wang Y, Cleetus A, Mohamed MA, Sonar P, Feng W, Ökten Z, Ou G. Neurons dispose of hyperactive kinesin into glial cells for clearance. EMBO J 2024; 43:2606-2635. [PMID: 38806659 PMCID: PMC11217292 DOI: 10.1038/s44318-024-00118-0] [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: 11/22/2023] [Revised: 04/06/2024] [Accepted: 04/25/2024] [Indexed: 05/30/2024] Open
Abstract
Microtubule-based kinesin motor proteins are crucial for intracellular transport, but their hyperactivation can be detrimental for cellular functions. This study investigated the impact of a constitutively active ciliary kinesin mutant, OSM-3CA, on sensory cilia in C. elegans. Surprisingly, we found that OSM-3CA was absent from cilia but underwent disposal through membrane abscission at the tips of aberrant neurites. Neighboring glial cells engulf and eliminate the released OSM-3CA, a process that depends on the engulfment receptor CED-1. Through genetic suppressor screens, we identified intragenic mutations in the OSM-3CA motor domain and mutations inhibiting the ciliary kinase DYF-5, both of which restored normal cilia in OSM-3CA-expressing animals. We showed that conformational changes in OSM-3CA prevent its entry into cilia, and OSM-3CA disposal requires its hyperactivity. Finally, we provide evidence that neurons also dispose of hyperactive kinesin-1 resulting from a clinic variant associated with amyotrophic lateral sclerosis, suggesting a widespread mechanism for regulating hyperactive kinesins.
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Affiliation(s)
- Chao Xie
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Guanghan Chen
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Ming Li
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Peng Huang
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Zhe Chen
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Kexin Lei
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Dong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, 100101, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yuhe Wang
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- State Key Laboratory for Membrane Biology, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Augustine Cleetus
- Physik Department E22, Technische Universitat Munchen, James-Franck-Strasse, Garching, 85748, Germany
| | - Mohamed Aa Mohamed
- Physik Department E22, Technische Universitat Munchen, James-Franck-Strasse, Garching, 85748, Germany
| | - Punam Sonar
- Physik Department E22, Technische Universitat Munchen, James-Franck-Strasse, Garching, 85748, Germany
| | - Wei Feng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, 100101, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zeynep Ökten
- Physik Department E22, Technische Universitat Munchen, James-Franck-Strasse, Garching, 85748, Germany
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.
- Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing, China.
- McGovern Institute for Brain Research, Tsinghua University, Beijing, China.
- State Key Laboratory for Membrane Biology, Beijing, China.
- School of Life Sciences, Tsinghua University, Beijing, China.
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3
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Liu T, Cao L, Mladenov M, Jegou A, Way M, Moores CA. Cortactin stabilizes actin branches by bridging activated Arp2/3 to its nucleated actin filament. Nat Struct Mol Biol 2024; 31:801-809. [PMID: 38267598 PMCID: PMC11102864 DOI: 10.1038/s41594-023-01205-2] [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: 07/25/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
Regulation of the assembly and turnover of branched actin filament networks nucleated by the Arp2/3 complex is essential during many cellular processes, including cell migration and membrane trafficking. Cortactin is important for actin branch stabilization, but the mechanism by which this occurs is unclear. Given this, we determined the structure of vertebrate cortactin-stabilized Arp2/3 actin branches using cryogenic electron microscopy. We find that cortactin interacts with the new daughter filament nucleated by the Arp2/3 complex at the branch site, rather than the initial mother actin filament. Cortactin preferentially binds activated Arp3. It also stabilizes the F-actin-like interface of activated Arp3 with the first actin subunit of the new filament, and its central repeats extend along successive daughter-filament subunits. The preference of cortactin for activated Arp3 explains its retention at the actin branch and accounts for its synergy with other nucleation-promoting factors in regulating branched actin network dynamics.
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Affiliation(s)
- Tianyang Liu
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | - Luyan Cao
- The Francis Crick Institute, London, UK
| | | | - Antoine Jegou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Michael Way
- The Francis Crick Institute, London, UK.
- Department of Infectious Disease, Imperial College, London, UK.
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK.
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4
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Miller SG, Hoh M, Ebmeier CC, Tay JW, Ahn NG. Cooperative polarization of MCAM/CD146 and ERM family proteins in melanoma. Mol Biol Cell 2024; 35:ar31. [PMID: 38117590 PMCID: PMC10916866 DOI: 10.1091/mbc.e23-06-0255] [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: 06/28/2023] [Revised: 11/22/2023] [Accepted: 12/15/2023] [Indexed: 12/22/2023] Open
Abstract
The WRAMP structure is a protein network associated with tail-end actomyosin contractility, membrane retraction, and directional persistence during cell migration. A marker of WRAMP structures is melanoma cell adhesion molecule (MCAM) which dynamically polarizes to the cell rear. However, factors that mediate MCAM polarization are still unknown. In this study, BioID using MCAM as bait identifies the ERM family proteins, moesin, ezrin, and radixin, as WRAMP structure components. We also present a novel image analysis pipeline, Protein Polarity by Percentile ("3P"), which classifies protein polarization using machine learning and facilitates quantitative analysis. Using 3P, we find that depletion of moesin, and to a lesser extent ezrin, decreases the proportion of cells with polarized MCAM. Furthermore, although copolarized MCAM and ERM proteins show high spatial overlap, 3P identifies subpopulations with ERM proteins closer to the cell periphery. Live-cell imaging confirms that MCAM and ERM protein polarization is tightly coordinated, but ERM proteins enrich at the cell edge first. Finally, deletion of a juxtamembrane segment in MCAM previously shown to promote ERM protein interactions impedes MCAM polarization. Our findings highlight the requirement for ERM proteins in recruitment of MCAM to WRAMP structures and an advanced computational tool to characterize protein polarization.
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Affiliation(s)
- Suzannah G. Miller
- Department of Biochemistry, University of Colorado Boulder, Boulder CO 80303
| | - Maria Hoh
- Department of Biochemistry, University of Colorado Boulder, Boulder CO 80303
| | | | - Jian Wei Tay
- BioFrontiers Institute, University of Colorado Boulder, Boulder CO 80303
| | - Natalie G. Ahn
- Department of Biochemistry, University of Colorado Boulder, Boulder CO 80303
- BioFrontiers Institute, University of Colorado Boulder, Boulder CO 80303
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5
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McGuirk ER, Koundinya N, Nagarajan P, Padrick SB, Goode BL. Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization. Eur J Cell Biol 2024; 103:151378. [PMID: 38071835 PMCID: PMC10843626 DOI: 10.1016/j.ejcb.2023.151378] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/02/2023] [Accepted: 12/02/2023] [Indexed: 01/28/2024] Open
Abstract
How cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIRF microscopy, we observe that GMF's branch destabilizing activities are potently blocked by cortactin (IC50 = 1.3 nM) and that this inhibition requires direct interactions of cortactin with Arp2/3 complex. The simplest model that would explain these results is competition for binding Arp2/3 complex. However, we find that cortactin and GMF do not compete for free Arp2/3 complex in solution. Further, we use single molecule analysis to show that cortactin's on-rate (3 ×107 s-1 M-1) and off-rate (0.03 s-1) at branch junctions are minimally affected by excess GMF. Together, these results show that cortactin binds with high affinity to branch junctions, where it blocks the destabilizing effects of GMF, possibly by a mechanism that is allosteric in nature. In addition, the affinities we measure for cortactin at actin filament branch junctions (Kd = 0.9 nM) and filament sides (Kd = 206 nM) are approximately 20-fold stronger than previously reported. These observations contribute to an emerging view of molecular complexity in how Arp2/3 complex is regulated through the integration of multiple inputs.
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Affiliation(s)
- Emma R McGuirk
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Neha Koundinya
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Priyashree Nagarajan
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
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6
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Cao L, Way M. The stabilization of Arp2/3 complex generated actin filaments. Biochem Soc Trans 2024; 52:343-352. [PMID: 38288872 PMCID: PMC10903444 DOI: 10.1042/bst20230638] [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: 11/01/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 02/29/2024]
Abstract
The Arp2/3 complex, which generates both branched but also linear actin filaments via activation of SPIN90, is evolutionarily conserved in eukaryotes. Several factors regulate the stability of filaments generated by the Arp2/3 complex to maintain the dynamics and architecture of actin networks. In this review, we summarise recent studies on the molecular mechanisms governing the tuning of Arp2/3 complex nucleated actin filaments, which includes investigations using microfluidics and single-molecule imaging to reveal the mechanosensitivity, dissociation and regeneration of actin branches. We also discuss the high-resolution cryo-EM structure of cortactin bound to actin branches, as well as the differences and similarities between the stability of Arp2/3 complex nucleated branches and linear filaments. These new studies provide a clearer picture of the stabilisation of Arp2/3 nucleated filaments at the molecular level. We also identified gaps in our understanding of how different factors collectively contribute to the stabilisation of Arp2/3 complex-generated actin networks.
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Affiliation(s)
- LuYan Cao
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
- Department of Infectious Disease, Imperial College, London W2 1PG, U.K
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7
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Li YY, Ji SF, Fu XB, Jiang YF, Sun XY. Biomaterial-based mechanical regulation facilitates scarless wound healing with functional skin appendage regeneration. Mil Med Res 2024; 11:13. [PMID: 38369464 PMCID: PMC10874556 DOI: 10.1186/s40779-024-00519-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/30/2024] [Indexed: 02/20/2024] Open
Abstract
Scar formation resulting from burns or severe trauma can significantly compromise the structural integrity of skin and lead to permanent loss of skin appendages, ultimately impairing its normal physiological function. Accumulating evidence underscores the potential of targeted modulation of mechanical cues to enhance skin regeneration, promoting scarless repair by influencing the extracellular microenvironment and driving the phenotypic transitions. The field of skin repair and skin appendage regeneration has witnessed remarkable advancements in the utilization of biomaterials with distinct physical properties. However, a comprehensive understanding of the underlying mechanisms remains somewhat elusive, limiting the broader application of these innovations. In this review, we present two promising biomaterial-based mechanical approaches aimed at bolstering the regenerative capacity of compromised skin. The first approach involves leveraging biomaterials with specific biophysical properties to create an optimal scarless environment that supports cellular activities essential for regeneration. The second approach centers on harnessing mechanical forces exerted by biomaterials to enhance cellular plasticity, facilitating efficient cellular reprogramming and, consequently, promoting the regeneration of skin appendages. In summary, the manipulation of mechanical cues using biomaterial-based strategies holds significant promise as a supplementary approach for achieving scarless wound healing, coupled with the restoration of multiple skin appendage functions.
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Affiliation(s)
- Ying-Ying Li
- Research Center for Tissue Repair and Regeneration Affiliated to the Medical Innovation Research Department, Chinese PLA General Hospital and PLA Medical College; PLA Key Laboratory of Tissue Repair and Regenerative Medicine and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration; Research Unit of Trauma Care, Tissue Repair and Regeneration, Chinese Academy of Medical Sciences, 2019RU051, Beijing, 100048, China
| | - Shuai-Fei Ji
- Research Center for Tissue Repair and Regeneration Affiliated to the Medical Innovation Research Department, Chinese PLA General Hospital and PLA Medical College; PLA Key Laboratory of Tissue Repair and Regenerative Medicine and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration; Research Unit of Trauma Care, Tissue Repair and Regeneration, Chinese Academy of Medical Sciences, 2019RU051, Beijing, 100048, China
| | - Xiao-Bing Fu
- Research Center for Tissue Repair and Regeneration Affiliated to the Medical Innovation Research Department, Chinese PLA General Hospital and PLA Medical College; PLA Key Laboratory of Tissue Repair and Regenerative Medicine and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration; Research Unit of Trauma Care, Tissue Repair and Regeneration, Chinese Academy of Medical Sciences, 2019RU051, Beijing, 100048, China.
| | - Yu-Feng Jiang
- Department of Tissue Regeneration and Wound Repair, Chinese PLA General Hospital, Beijing, 100853, China.
| | - Xiao-Yan Sun
- Research Center for Tissue Repair and Regeneration Affiliated to the Medical Innovation Research Department, Chinese PLA General Hospital and PLA Medical College; PLA Key Laboratory of Tissue Repair and Regenerative Medicine and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration; Research Unit of Trauma Care, Tissue Repair and Regeneration, Chinese Academy of Medical Sciences, 2019RU051, Beijing, 100048, China.
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8
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Ghasemi F, Cao L, Mladenov M, Guichard B, Way M, Jégou A, Romet-Lemonne G. Regeneration of actin filament branches from the same Arp2/3 complex. SCIENCE ADVANCES 2024; 10:eadj7681. [PMID: 38277459 PMCID: PMC10816697 DOI: 10.1126/sciadv.adj7681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 12/27/2023] [Indexed: 01/28/2024]
Abstract
Branched actin filaments are found in many key cellular structures. Branches are nucleated by the Arp2/3 complex activated by nucleation-promoting factor (NPF) proteins and bound to the side of preexisting "mother" filaments. Over time, branches dissociate from their mother filament, leading to network reorganization and turnover, but this mechanism is less understood. Here, using microfluidics and purified proteins, we examined the dissociation of individual branches under controlled biochemical and mechanical conditions. We observe that the Arp2/3 complex remains bound to the mother filament after most debranching events, even when accelerated by force. Strikingly, this surviving Arp2/3 complex readily nucleates a new actin filament branch, without being activated anew by an NPF: It simply needs to exchange its nucleotide and bind an actin monomer. The protein glia maturation factor (GMF), which accelerates debranching, prevents branch renucleation. Our results suggest that actin filament renucleation can provide a self-repair mechanism, helping branched networks to sustain mechanical stress in cells over extended periods of time.
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Affiliation(s)
- Foad Ghasemi
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - LuYan Cao
- The Francis Crick Institute, London, UK
| | | | - Bérengère Guichard
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Michael Way
- The Francis Crick Institute, London, UK
- Department of Infectious Disease, Imperial College, London, UK
| | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
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9
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Hsu CR, Sangha G, Fan W, Zheng J, Sugioka K. Contractile ring mechanosensation and its anillin-dependent tuning during early embryogenesis. Nat Commun 2023; 14:8138. [PMID: 38065974 PMCID: PMC10709429 DOI: 10.1038/s41467-023-43996-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Cytokinesis plays crucial roles in morphogenesis. Previous studies have examined how tissue mechanics influences the position and closure direction of the contractile ring. However, the mechanisms by which the ring senses tissue mechanics remain largely elusive. Here, we show the mechanism of contractile ring mechanosensation and its tuning during asymmetric ring closure of Caenorhabditis elegans embryos. Integrative analysis of ring closure and cell cortex dynamics revealed that mechanical suppression of the ring-directed cortical flow is associated with asymmetric ring closure. Consistently, artificial obstruction of ring-directed cortical flow induces asymmetric ring closure in otherwise symmetrically dividing cells. Anillin is vital for mechanosensation. Our genetic analysis suggests that the positive feedback loop among ring-directed cortical flow, myosin enrichment, and ring constriction constitutes a mechanosensitive pathway driving asymmetric ring closure. These findings and developed tools should advance the 4D mechanobiology of cytokinesis in more complex tissues.
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Affiliation(s)
- Christina Rou Hsu
- Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
- Department of Zoology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
| | - Gaganpreet Sangha
- Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
- Department of Zoology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
| | - Wayne Fan
- Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
- Department of Zoology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
| | - Joey Zheng
- Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
- Department of Zoology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada
| | - Kenji Sugioka
- Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada.
- Department of Zoology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T1Z3, Canada.
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10
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Goode BL, Eskin J, Shekhar S. Mechanisms of actin disassembly and turnover. J Cell Biol 2023; 222:e202309021. [PMID: 37948068 PMCID: PMC10638096 DOI: 10.1083/jcb.202309021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/21/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023] Open
Abstract
Cellular actin networks exhibit a wide range of sizes, shapes, and architectures tailored to their biological roles. Once assembled, these filamentous networks are either maintained in a state of polarized turnover or induced to undergo net disassembly. Further, the rates at which the networks are turned over and/or dismantled can vary greatly, from seconds to minutes to hours or even days. Here, we review the molecular machinery and mechanisms employed in cells to drive the disassembly and turnover of actin networks. In particular, we highlight recent discoveries showing that specific combinations of conserved actin disassembly-promoting proteins (cofilin, GMF, twinfilin, Srv2/CAP, coronin, AIP1, capping protein, and profilin) work in concert to debranch, sever, cap, and depolymerize actin filaments, and to recharge actin monomers for new rounds of assembly.
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Affiliation(s)
- Bruce L. Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, USA
| | - Julian Eskin
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, USA
| | - Shashank Shekhar
- Departments of Physics, Cell Biology and Biochemistry, Emory University, Atlanta, GA, USA
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11
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Bai Y, Zhao F, Wu T, Chen F, Pang X. Actin polymerization and depolymerization in developing vertebrates. Front Physiol 2023; 14:1213668. [PMID: 37745245 PMCID: PMC10515290 DOI: 10.3389/fphys.2023.1213668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Development is a complex process that occurs throughout the life cycle. F-actin, a major component of the cytoskeleton, is essential for the morphogenesis of tissues and organs during development. F-actin is formed by the polymerization of G-actin, and the dynamic balance of polymerization and depolymerization ensures proper cellular function. Disruption of this balance results in various abnormalities and defects or even embryonic lethality. Here, we reviewed recent findings on the structure of G-actin and F-actin and the polymerization of G-actin to F-actin. We also focused on the functions of actin isoforms and the underlying mechanisms of actin polymerization/depolymerization in cellular and organic morphogenesis during development. This information will extend our understanding of the role of actin polymerization in the physiologic or pathologic processes during development and may open new avenues for developing therapeutics for embryonic developmental abnormalities or tissue regeneration.
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Affiliation(s)
- Yang Bai
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Feng Zhao
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Tingting Wu
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Fangchun Chen
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Xiaoxiao Pang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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12
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Singh Y, Hocky GM, Nolen BJ. Molecular dynamics simulations support a multistep pathway for activation of branched actin filament nucleation by Arp2/3 complex. J Biol Chem 2023; 299:105169. [PMID: 37595874 PMCID: PMC10514467 DOI: 10.1016/j.jbc.2023.105169] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/20/2023] Open
Abstract
Actin-related protein 2/3 complex (Arp2/3 complex) catalyzes the nucleation of branched actin filaments that push against membranes in processes like cellular motility and endocytosis. During activation by WASP proteins, the complex must bind WASP and engage the side of a pre-existing (mother) filament before a branched filament is nucleated. Recent high-resolution structures of activated Arp2/3 complex revealed two major sets of activating conformational changes. How these activating conformational changes are triggered by interactions of Arp2/3 complex with actin filaments and WASP remains unclear. Here we use a recent high-resolution structure of Arp2/3 complex at a branch junction to design all-atom molecular dynamics simulations that elucidate the pathway between the active and inactive states. We ran a total of ∼4.6 microseconds of both unbiased and steered all-atom molecular dynamics simulations starting from three different binding states, including Arp2/3 complex within a branch junction, bound only to a mother filament, and alone in solution. These simulations indicate that the contacts with the mother filament are mostly insensitive to the massive rigid body motion that moves Arp2 and Arp3 into a short pitch helical (filament-like) arrangement, suggesting actin filaments alone do not stimulate the short pitch conformational change. In contrast, contacts with the mother filament stabilize subunit flattening in Arp3, an intrasubunit change that converts Arp3 from a conformation that mimics an actin monomer to one that mimics a filamentous actin subunit. Our results support a multistep activation pathway that has important implications for understanding how WASP-mediated activation allows Arp2/3 complex to assemble force-producing actin networks.
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Affiliation(s)
| | - Glen M Hocky
- Department of Chemistry, New York University; Simons Center for Computational Physical Chemistry, New York University.
| | - Brad J Nolen
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon.
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13
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Tavares Tamborindeguy M, Lorenzatto PF, Lamers ML, Lenz G. Asymmetric mitosis contributes to different migratory performance in sister cells. Exp Cell Res 2023:113715. [PMID: 37429373 DOI: 10.1016/j.yexcr.2023.113715] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
In cancer, cell migration contributes to the spread of tumor cells resulting in metastasis. Heterogeneity in the migration capacity can produce individual cells with heightened capacity leading to invasion and metastasis. Our hypothesis is that cell migration characteristics can divide asymmetrically in mitosis, allowing a subset of cells to have a larger contribution to invasion and metastasis. Therefore, our aim is to elucidate whether sister cells have different migratory capacity and analyze if this difference is defined by mitosis. Through time-lapse videos, we analyzed migration speed, directionality, maximum displacement of each trajectory, and velocity as well as cell area and polarity and then compared the values between mother-daughter cells and between sister cells of three tumor cell lines (A172, MCF7, SCC25) and two normal cell lines (MRC5 and CHO·K1 cells). We observed that daughter cells had a different migratory phenotype compared to their mothers, and one single mitosis is enough for the sisters behave like nonrelated cells. However, mitosis did not influence cell area and polarity dynamics. These findings indicates that migration performance is not heritable, and that asymmetric cell division might have an important impact on cancer invasion and metastasis, by producing cells with different migratory capacity.
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Affiliation(s)
- Maurício Tavares Tamborindeguy
- Departamento de Biofísica, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil; Centro de Biotecnologia, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil
| | - Paola Farias Lorenzatto
- Departamento de Biofísica, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil; Centro de Biotecnologia, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil
| | - Marcelo Lazzaron Lamers
- Departamento de Ciencias Morfológicas, ICBS, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Guido Lenz
- Departamento de Biofísica, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil; Centro de Biotecnologia, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil.
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14
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Sun J, Zhong X, Fu X, Miller H, Lee P, Yu B, Liu C. The Actin Regulators Involved in the Function and Related Diseases of Lymphocytes. Front Immunol 2022; 13:799309. [PMID: 35371070 PMCID: PMC8965893 DOI: 10.3389/fimmu.2022.799309] [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: 10/21/2021] [Accepted: 02/01/2022] [Indexed: 11/21/2022] Open
Abstract
Actin is an important cytoskeletal protein involved in signal transduction, cell structure and motility. Actin regulators include actin-monomer-binding proteins, Wiskott-Aldrich syndrome (WAS) family of proteins, nucleation proteins, actin filament polymerases and severing proteins. This group of proteins regulate the dynamic changes in actin assembly/disassembly, thus playing an important role in cell motility, intracellular transport, cell division and other basic cellular activities. Lymphocytes are important components of the human immune system, consisting of T-lymphocytes (T cells), B-lymphocytes (B cells) and natural killer cells (NK cells). Lymphocytes are indispensable for both innate and adaptive immunity and cannot function normally without various actin regulators. In this review, we first briefly introduce the structure and fundamental functions of a variety of well-known and newly discovered actin regulators, then we highlight the role of actin regulators in T cell, B cell and NK cell, and finally provide a landscape of various diseases associated with them. This review provides new directions in exploring actin regulators and promotes more precise and effective treatments for related diseases.
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Affiliation(s)
- Jianxuan Sun
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department and Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingyu Zhong
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoyu Fu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Heather Miller
- Cytek Biosciences, R&D Clinical Reagents, Fremont, CA, United States
| | - Pamela Lee
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Bing Yu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chaohong Liu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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15
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Gautreau AM, Fregoso FE, Simanov G, Dominguez R. Nucleation, stabilization, and disassembly of branched actin networks. Trends Cell Biol 2021; 32:421-432. [PMID: 34836783 PMCID: PMC9018471 DOI: 10.1016/j.tcb.2021.10.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/19/2021] [Accepted: 10/22/2021] [Indexed: 12/18/2022]
Abstract
Arp2/3 complex is an actin filament nucleation and branching machinery conserved in all eukaryotes from yeast to human. Arp2/3 complex branched networks generate pushing forces that drive cellular processes ranging from membrane remodeling to cell and organelle motility. Several molecules regulate these processes by directly inhibiting or activating Arp2/3 complex and by stabilizing or disassembling branched networks. Here, we review recent advances in our understanding of Arp2/3 complex regulation, including high-resolution cryoelectron microscopy (cryo-EM) structures that illuminate the mechanisms of Arp2/3 complex activation and branch formation, and novel cellular pathways of branch formation, stabilization, and debranching. We also identify major gaps in our understanding of Arp2/3 complex inhibition and branch stabilization and disassembly.
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Affiliation(s)
- Alexis M Gautreau
- Laboratoire de Biologie Structurale de la Cellule, CNRS, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France.
| | - Fred E Fregoso
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gleb Simanov
- Laboratoire de Biologie Structurale de la Cellule, CNRS, École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Roberto Dominguez
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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