1
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Paraschiakos T, Li J, Scholz J, Han SJ, Deckers M, Pogenberg V, Faix J, Windhorst S. A high affinity Sybody blocks Cofilin-1 binding to F-actin in vitro and in cancer cells. Biochem Pharmacol 2025; 236:116866. [PMID: 40064451 DOI: 10.1016/j.bcp.2025.116866] [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: 11/22/2024] [Revised: 02/26/2025] [Accepted: 03/06/2025] [Indexed: 03/16/2025]
Abstract
Upregulation of the actin-severing protein Cofilin-1 is implicated in enhancing malignancy of various cancer types by promoting actin turnover and increasing cellular motility. Despite the importance of targeting Cofilin-1, currently there is a lack of inhibitors specifically targeting its actin-severing activity. To address this issue, we generated synthetic anti-Cofilin-1 nanobodies (Sybodies) that interfere with human Cofilin-1 binding to filamentous actin. We identified four high affinity Sybodies against human Cofilin-1 with dissociation constants (KD) in the nanomolar range that inhibited G-actin sequestration, and actin-severing activity of Cofilin-1 in vitro. Notably, Sybody B12, with the lowest KD of approximately 27 nM, competitively blocked actin binding to Cofilin-1, and also inhibited G-actin sequestration of murine Cofilin-1. The crystal structure of the Sybody-B12-Cofilin-1 complex, resolved at 1.8 Å, revealed that Sybody B12 binds to the G-actin binding site of Cofilin-1, showing that Sybody B12 engages the same binding site on Cofilin-1 as actin. Consistently, transient expression of mPlum-tagged Sybody B12 in human H1299 lung cancer cells inhibited the formation of enhanced green fluorescent protein (EGFP)-Cofilin-actin rods. Notably, stable expression of Sybody B12 did not affect viability of H1299 cells, and no compensatory up-regulation of Cofilin-2 or actin-depolymerization factor (ADF) mRNA were detectable in Sybody B12 expressing H1299 cells. Together, these findings suggest that Sybody B12 exhibits a strong potential as tool for inhibiting the interaction of Cofilin-1 with actin. In addition, it could serve as a promising lead structure for designing Cofilin-1 inhibitors in silico.
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Affiliation(s)
- Themistoklis Paraschiakos
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Jing Li
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Jonas Scholz
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Soo-Ji Han
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Markus Deckers
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Vivian Pogenberg
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Jan Faix
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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2
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Frezarim GB, Mota LFM, Fonseca LFS, Salatta BM, Arikawa LM, Schmidt PI, Silva DBS, Albuquerque LG. Multi-omics integration identifies molecular markers and biological pathways for carcass and meat quality traits in Nellore cattle. Sci Rep 2025; 15:10467. [PMID: 40140445 PMCID: PMC11947269 DOI: 10.1038/s41598-025-93714-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2024] [Accepted: 03/10/2025] [Indexed: 03/28/2025] Open
Abstract
Understanding the biological factors that influence carcass and meat quality traits in Nellore cattle requires a clear interpretation of molecular complexity and its variations at different levels of expression. Hence, this study aimed to elucidate the biological control of carcass and meat quality traits in Nellore cattle by integrating genome-wide association study (GWAS), transcriptomic, and proteomic data, focusing on identifying key genes and pathways. GWAS analysis was performed using weighted single-step GBLUP with two iterations. RNA-Seq and proteomic analyses were performed on 24 muscle samples from animals with divergent adjusted phenotypic values (12 for high and 12 for low), for meat tenderness, ribeye area (REA), marbling, and backfat thickness (BFT). The phenotypic values were adjusted for the systematic effects of contemporary groups and age. Differential expression analyses indicated that genes associated with the promotion of growth processes, such as FRZB, IGFBP5 and SEMA6C, exhibited overexpression within the group characterized by higher meat tenderness that inhibits cellular cycles and growth (RTN4 and RB1) were downregulated. Proteins related to heat shock, structural functions, and metabolic regulation also affected the higher meat tenderness group. For marbling, actin-binding proteins, microtubule-forming proteins, and structural proteins were downregulated, while genes involved in fatty acid composition and synthesis were upregulated, with the key genes and transcripts CAND1, ACTN4, FGFR2, and NCOR2 identified. For BFT, neuronal genes, transcripts, and proteins associated with actin cytoskeleton organization and microtubule formation were found. Key genes related to ubiquitination, regulation of energy metabolism, and tissue remodeling were also identified. These findings provide a better understanding of genes, transcripts, proteins, and metabolic pathways involved in carcass and meat quality traits in Nellore cattle.
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Affiliation(s)
- Gabriela B Frezarim
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Lucio F M Mota
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil.
| | - Larissa F S Fonseca
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Bruna M Salatta
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Leonardo M Arikawa
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Patrícia I Schmidt
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Danielly B S Silva
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil
| | - Lucia G Albuquerque
- Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil.
- National Council for Science and Technological Development, Brasilia, DF, 71605-001, Brazil.
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3
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Uyeda TQP, Yamazaki Y, Kijima ST, Noguchi TQP, Ngo KX. Multiple Mechanisms to Regulate Actin Functions: "Fundamental" Versus Lineage-Specific Mechanisms and Hierarchical Relationships. Biomolecules 2025; 15:279. [PMID: 40001582 PMCID: PMC11853071 DOI: 10.3390/biom15020279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2024] [Revised: 02/07/2025] [Accepted: 02/10/2025] [Indexed: 02/27/2025] Open
Abstract
Eukaryotic actin filaments play a central role in numerous cellular functions, with each function relying on the interaction of actin filaments with specific actin-binding proteins. Understanding the mechanisms that regulate these interactions is key to uncovering how actin filaments perform diverse roles at different cellular locations. Several distinct classes of actin regulatory mechanisms have been proposed and experimentally supported. However, these mechanisms vary in their nature and hierarchy. For instance, some operate under the control of others, highlighting hierarchical relationships. Additionally, while certain mechanisms are fundamental and ubiquitous across eukaryotes, others are lineage-specific. Here, we emphasize the fundamental importance and functional significance of the following actin regulatory mechanisms: the biochemical regulation of actin nucleators, the ATP hydrolysis-dependent aging of actin filaments, thermal fluctuation- and mechanical strain-dependent conformational changes of actin filaments, and cooperative conformational changes induced by actin-binding proteins.
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Affiliation(s)
- Taro Q. P. Uyeda
- Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Shinjuku, Japan
| | - Yosuke Yamazaki
- RIKEN Center for Biosystems Dynamics Research, Yokohama 230-0045, Kanagawa, Japan;
| | - Saku T. Kijima
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Ibaraki, Japan;
| | - Taro Q. P. Noguchi
- Department of Chemical Science and Engineering, National Institute of Technology, Miyakonojo College, Miyakonojo 885-0006, Miyazaki, Japan;
| | - Kien Xuan Ngo
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa 920-1192, Ishikawa, Japan;
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4
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Chikireddy J, Lengagne L, Le Borgne R, Durieu C, Wioland H, Romet-Lemonne G, Jégou A. Fascin-induced bundling protects actin filaments from disassembly by cofilin. J Cell Biol 2024; 223:e202312106. [PMID: 38497788 PMCID: PMC10949937 DOI: 10.1083/jcb.202312106] [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: 12/20/2023] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024] Open
Abstract
Actin filament turnover plays a central role in shaping actin networks, yet the feedback mechanism between network architecture and filament assembly dynamics remains unclear. The activity of ADF/cofilin, the main protein family responsible for filament disassembly, has been mainly studied at the single filament level. This study unveils that fascin, by crosslinking filaments into bundles, strongly slows down filament disassembly by cofilin. We show that this is due to a markedly slower initiation of the first cofilin clusters, which occurs up to 100-fold slower on large bundles compared with single filaments. In contrast, severing at cofilin cluster boundaries is unaffected by fascin bundling. After the formation of an initial cofilin cluster on a filament within a bundle, we observed the local removal of fascin. Notably, the formation of cofilin clusters on adjacent filaments is highly enhanced, locally. We propose that this interfilament cooperativity arises from the local propagation of the cofilin-induced change in helicity from one filament to the other filaments of the bundle. Overall, taking into account all the above reactions, we reveal that fascin crosslinking slows down the disassembly of actin filaments by cofilin. These findings highlight the important role played by crosslinkers in tuning actin network turnover by modulating the activity of other regulatory proteins.
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Affiliation(s)
| | - Léana Lengagne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Rémi Le Borgne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Catherine Durieu
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Hugo Wioland
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | | | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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5
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Towsif EM, Miller BA, Ulrichs H, Shekhar S. Multicomponent depolymerization of actin filament pointed ends by cofilin and cyclase-associated protein depends upon filament age. Eur J Cell Biol 2024; 103:151423. [PMID: 38796920 PMCID: PMC12045339 DOI: 10.1016/j.ejcb.2024.151423] [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: 10/02/2023] [Revised: 05/18/2024] [Accepted: 05/19/2024] [Indexed: 05/29/2024] Open
Abstract
Intracellular actin networks assemble through the addition of ATP-actin subunits at the growing barbed ends of actin filaments. This is followed by "aging" of the filament via ATP hydrolysis and subsequent phosphate release. Aged ADP-actin subunits thus "treadmill" through the filament before being released back into the cytoplasmic monomer pool as a result of depolymerization at filament pointed ends. The necessity for aging before filament disassembly is reinforced by preferential binding of cofilin to aged ADP-actin subunits over newly-assembled ADP-Pi actin subunits in the filament. Consequently, investigations into how cofilin influences pointed-end depolymerization have, thus far, focused exclusively on aged ADP-actin filaments. Using microfluidics-assisted Total Internal Reflection Fluorescence (mf-TIRF) microscopy, we reveal that, similar to their effects on ADP filaments, cofilin and cyclase-associated protein (CAP) also promote pointed-end depolymerization of ADP-Pi filaments. Interestingly, the maximal rates of ADP-Pi filament depolymerization by CAP and cofilin together remain approximately 20-40 times lower than for ADP filaments. Further, we find that the promotion of ADP-Pi pointed-end depolymerization is conserved for all three mammalian cofilin isoforms. Taken together, the mechanisms presented here open the possibility of newly-assembled actin filaments being directly disassembled from their pointed-ends, thus bypassing the slow step of Pi release in the aging process.
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Affiliation(s)
- Ekram M Towsif
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Blake Andrew Miller
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Heidi Ulrichs
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Shashank Shekhar
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA.
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6
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Megaw R, Moye A, Zhang Z, Newton F, McPhie F, Murphy LC, McKie L, He F, Jungnickel MK, von Kriegsheim A, Tennant PA, Brotherton C, Gurniak C, Gross AK, Machesky LM, Wensel TG, Mill P. Ciliary tip actin dynamics regulate photoreceptor outer segment integrity. Nat Commun 2024; 15:4316. [PMID: 38773095 PMCID: PMC11109262 DOI: 10.1038/s41467-024-48639-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: 06/05/2023] [Accepted: 05/09/2024] [Indexed: 05/23/2024] Open
Abstract
As signalling organelles, cilia regulate their G protein-coupled receptor content by ectocytosis, a process requiring localised actin dynamics to alter membrane shape. Photoreceptor outer segments comprise an expanse of folded membranes (discs) at the tip of highly-specialised connecting cilia, into which photosensitive GPCRs are concentrated. Discs are shed and remade daily. Defects in this process, due to mutations, cause retinitis pigmentosa (RP). Whilst fundamental for vision, the mechanism of photoreceptor disc generation is poorly understood. Here, we show membrane deformation required for disc genesis is driven by dynamic actin changes in a process akin to ectocytosis. We show RPGR, a leading RP gene, regulates actin-binding protein activity central to this process. Actin dynamics, required for disc formation, are perturbed in Rpgr mouse models, leading to aborted membrane shedding as ectosome-like vesicles, photoreceptor death and visual loss. Actin manipulation partially rescues this, suggesting the pathway could be targeted therapeutically. These findings help define how actin-mediated dynamics control outer segment turnover.
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Affiliation(s)
- Roly Megaw
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK.
- Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh, EH3 9HA, UK.
| | - Abigail Moye
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhixian Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Fay Newton
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Fraser McPhie
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Laura C Murphy
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Lisa McKie
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Feng He
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Melissa K Jungnickel
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Alex von Kriegsheim
- Edinburgh Cancer Research United Kingdom Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Peter A Tennant
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Chloe Brotherton
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Christine Gurniak
- Institute fur Genetik, Universitat Bonn, Karlrobert-Kreiten-Strasse, 53115, Bonn, Germany
| | - Alecia K Gross
- University of Alabama at Birmingham, 2nd Ave South, Birmingham, AL, 35294, USA
| | - Laura M Machesky
- CRUK Scotland Institute, Switchback Road, Bearsden, Glasgow, G61 1BD, UK
- Department of Biochemistry, University of Cambridge, Cambridge, CB1 7UY, UK
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Pleasantine Mill
- MRC Human Genetics Unit, MRC Institute of Genetics & Cancer, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
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7
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Towsif EM, Miller BA, Ulrichs H, Shekhar S. Multicomponent depolymerization of actin filament pointed ends by cofilin and cyclase-associated protein depends upon filament age. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589566. [PMID: 38659736 PMCID: PMC11042253 DOI: 10.1101/2024.04.15.589566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Intracellular actin networks assemble through the addition of ATP-actin subunits at the growing barbed ends of actin filaments. This is followed by "aging" of the filament via ATP hydrolysis and subsequent phosphate release. Aged ADP-actin subunits thus "treadmill" through the filament before being released back into the cytoplasmic monomer pool as a result of depolymerization at filament pointed ends. The necessity for aging before filament disassembly is reinforced by preferential binding of cofilin to aged ADP-actin subunits over newly-assembled ADP-Pi actin subunits in the filament. Consequently, investigations into how cofilin influences pointed-end depolymerization have, thus far, focused exclusively on aged ADP-actin filaments. Using microfluidics-assisted Total Internal Reflection Fluorescence (mf-TIRF) microscopy, we reveal that, similar to their effects on ADP filaments, cofilin and cyclase-associated protein (CAP) also promote pointed-end depolymerization of ADP-Pi filaments. Interestingly, the maximal rates of ADP-Pi filament depolymerization by CAP and cofilin together remain approximately 20-40 times lower than for ADP filaments. Further, we find that the promotion of ADP-Pi pointed-end depolymerization is conserved for all three mammalian cofilin isoforms. Taken together, the mechanisms presented here open the possibility of newly-assembled actin filaments being directly disassembled from their pointed-ends, thus bypassing the slow step of Pi release in the aging process.
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Affiliation(s)
- Ekram M. Towsif
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322
| | - Blake Andrew Miller
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322
| | - Heidi Ulrichs
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322
| | - Shashank Shekhar
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322
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8
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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: 39] [Impact Index Per Article: 19.5] [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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9
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Towsif EM, Shekhar S. Cyclase-associated protein is a pro-formin anti-capping processive depolymerase of actin barbed and pointed ends. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569482. [PMID: 38076850 PMCID: PMC10705416 DOI: 10.1101/2023.11.30.569482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Cellular actin networks display distinct assembly and disassembly dynamics resulting from multicomponent reactions occurring primarily at the two ends and the sides of actin filaments [1-3]. While barbed ends are considered the hotspot of actin assembly [4], disassembly is thought to primarily occur via reactions on filament sides and pointed ends [3, 5-11]. Cyclase-associated protein (CAP) has emerged as the main protagonist of actin disassembly and remodeling - it collaborates with cofilin to increase pointed-end depolymerization by 300-fold [6, 7], promotes filament "coalescence" in presence of Abp1 [12], and accelerates nucleotide exchange to regenerate monomers for new rounds of assembly [13-15]. CAP has also been reported to enhance cofilin-mediated severing [16, 17], but these claims have since been challenged [7]. Using microfluidics-assisted three-color single-molecule imaging, we now reveal that CAP also has important functions at filament barbed ends. We reveal that CAP is a processive barbed-end depolymerase capable of tracking both ends of the filament. Each CAP binding event leads to removal of about 5,175 and 620 subunits from the barbed and pointed ends respectively. We find that the WH2 domain is essential, and the CARP domain is dispensable for barbed-end depolymerization. We show that CAP co-localizes with barbed-end bound formin and capping protein, in the process increasing residence time of formin by 10-fold and promoting dissociation of CP by 4-fold. Our barbed-end observations combined with previously reported activities of CAP at pointed ends and sides, firmly establish CAP as a key player in actin dynamics.
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Affiliation(s)
- Ekram M. Towsif
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Shashank Shekhar
- Departments of Physics, Cell biology and Biochemistry, Emory University, Atlanta, GA 30322, USA
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10
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Alimov N, Hoeprich GJ, Padrick SB, Goode BL. Cyclase-associated protein interacts with actin filament barbed ends to promote depolymerization and formin displacement. J Biol Chem 2023; 299:105367. [PMID: 37863260 PMCID: PMC10692737 DOI: 10.1016/j.jbc.2023.105367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/04/2023] [Accepted: 10/12/2023] [Indexed: 10/22/2023] Open
Abstract
Cyclase-associated protein (CAP) has emerged as a central player in cellular actin turnover, but its molecular mechanisms of action are not yet fully understood. Recent studies revealed that the N terminus of CAP interacts with the pointed ends of actin filaments to accelerate depolymerization in conjunction with cofilin. Here, we use in vitro microfluidics-assisted TIRF microscopy to show that the C terminus of CAP promotes depolymerization at the opposite (barbed) ends of actin filaments. In the absence of actin monomers, full-length mouse CAP1 and C-terminal halves of CAP1 (C-CAP1) and CAP2 (C-CAP2) accelerate barbed end depolymerization. Using mutagenesis and structural modeling, we show that these activities are mediated by the WH2 and CARP domains of CAP. In addition, we observe that CAP collaborates with profilin to accelerate barbed end depolymerization and that these effects depend on their direct interaction, providing the first known example of CAP-profilin collaborative effects in regulating actin. In the presence of actin monomers, CAP1 attenuates barbed end growth and promotes formin dissociation. Overall, these findings demonstrate that CAP uses distinct domains and mechanisms to interact with opposite ends of actin filaments and drive turnover. Further, they contribute to the emerging view of actin barbed ends as sites of dynamic molecular regulation, where numerous proteins compete and cooperate with each other to tune polymer dynamics, similar to the rich complexity seen at microtubule ends.
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Affiliation(s)
- Nikita Alimov
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, USA
| | - Gregory J Hoeprich
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, USA.
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11
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Kandiyoth FB, Michelot A. Reconstitution of actin-based cellular processes: Why encapsulation changes the rules. Eur J Cell Biol 2023; 102:151368. [PMID: 37922812 DOI: 10.1016/j.ejcb.2023.151368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/02/2023] [Accepted: 10/20/2023] [Indexed: 11/07/2023] Open
Abstract
While in vitro reconstitution of cellular processes is progressing rapidly, the encapsulation of biomimetic systems to reproduce the cellular environment is a major challenge. Here we review the difficulties, using reconstitution of processes dependent on actin polymerization as an example. Some of the problems are purely technical, due to the need for engineering strategies to encapsulate concentrated solutions in micrometer-sized compartments. However, other significant issues arise from the reduction of experimental volumes, which alters the chemical evolution of these non-equilibrium systems. Important parameters to consider for successful reconstitutions are the amount of each component, their consumption and renewal rates to guarantee their continuous availability.
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Affiliation(s)
| | - Alphée Michelot
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France.
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12
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Dinet C, Michelot A. pH gradients guide ADF/cofilin isoforms in pollen tubes. J Cell Biol 2023; 222:e202310012. [PMID: 37824163 PMCID: PMC10568488 DOI: 10.1083/jcb.202310012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023] Open
Abstract
In a recent study, Wang et al. (https://doi.org/10.1083/jcb.202206074) demonstrate that subtle differences between two ADF/cofilin isoforms allow fine spatial regulation of the actin cytoskeleton in pollen tubes. This article illustrates how two similar proteins have progressively evolved to adapt their localization and activity according to the cellular environment.
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Affiliation(s)
- Céline Dinet
- Aix Marseille University, CNRS, IBDM (UMR 7288), Turing Centre for Living Systems, Marseille, France
| | - Alphée Michelot
- Aix Marseille University, CNRS, IBDM (UMR 7288), Turing Centre for Living Systems, Marseille, France
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13
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Cao W, Taylor EW, De La Cruz EM. Cooperative ligand binding to a double-stranded Ising lattice-Application to cofilin binding to actin filaments. PNAS NEXUS 2023; 2:pgad331. [PMID: 37885622 PMCID: PMC10599439 DOI: 10.1093/pnasnexus/pgad331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/02/2023] [Indexed: 10/28/2023]
Abstract
Cooperative ligand binding to linear polymers is fundamental in many scientific disciplines, particularly biological and chemical physics and engineering. Such ligand binding interactions have been widely modeled using infinite one-dimensional (1D) Ising models even in cases where the linear polymers are more complex (e.g. actin filaments and other double-stranded linear polymers). Here, we use sequence-generating and transfer matrix methods to obtain an analytical method for cooperative equilibrium ligand binding to double-stranded Ising lattices. We use this exact solution to evaluate binding properties and features and analyze experimental binding data of cooperative binding of the regulatory protein, cofilin, to actin filaments. This analysis, with additional experimental information about the observed bound cofilin cluster sizes and filament structure, reveals that a bound cofilin promotes cooperative binding to its longitudinal nearest-neighbors but has very modest effects on lateral nearest-neighbors. The bound cofilin cluster sizes calculated from the best fit parameters from the double-stranded model are considerably larger than when calculated with the 1D model, consistent with experimental observations made by electron microscopy and fluorescence imaging. The exact solution obtained and the method for using the solution developed here can be widely used for analysis of variety of multistranded lattice systems.
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Affiliation(s)
- Wenxiang Cao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Edwin W Taylor
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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14
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Lewis M, Ono K, Qin Z, Johnsen RC, Baillie DL, Ono S. The α-arrestin SUP-13/ARRD-15 promotes isoform turnover of actin-interacting protein 1 in Caenorhabditis elegans striated muscle. PNAS NEXUS 2023; 2:pgad330. [PMID: 37869480 PMCID: PMC10590129 DOI: 10.1093/pnasnexus/pgad330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/02/2023] [Indexed: 10/24/2023]
Abstract
Precise arrangement of actin, myosin, and other regulatory components in a sarcomeric pattern is critical for producing contractile forces in striated muscles. Actin-interacting protein 1 (AIP1), also known as WD-repeat protein 1 (WDR1), is one of essential factors that regulate sarcomeric assembly of actin filaments. In the nematode Caenorhabditis elegans, mutation in unc-78, encoding one of the two AIP1 isoforms, causes severe disorganization of sarcomeric actin filaments and near paralysis, but mutation in sup-13 suppresses the unc-78-mutant phenotypes to restore nearly normal sarcomeric actin organization and worm motility. Here, we identified that sup-13 is a nonsense allele of arrd-15 encoding an α-arrestin. The sup-13/arrd-15 mutation suppressed the phenotypes of unc-78 null mutant but required aipl-1 that encodes a second AIP1 isoform. aipl-1 was normally expressed highly in embryos and downregulated in mature muscle. However, in the sup-13/arrd-15 mutant, the AIPL-1 protein was maintained at high levels in adult muscle to compensate for the absence of the UNC-78 protein. The sup-13/arrd-15 mutation caused accumulation of ubiquitinated AIPL-1 protein, suggesting that a normal function of sup-13/arrd-15 is to enhance degradation of ubiquitinated AIPL-1, thereby promoting transition of AIP1 isoforms from AIPL-1 to UNC-78 in developing muscle. These results suggest that α-arrestin is a novel factor to promote isoform turnover by enhancing protein degradation.
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Affiliation(s)
- Mario Lewis
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kanako Ono
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Zhaozhao Qin
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Robert C Johnsen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - David L Baillie
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Shoichiro Ono
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA
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15
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Colin A, Kotila T, Guérin C, Orhant-Prioux M, Vianay B, Mogilner A, Lappalainen P, Théry M, Blanchoin L. Recycling of the actin monomer pool limits the lifetime of network turnover. EMBO J 2023; 42:e112717. [PMID: 36912152 PMCID: PMC10152149 DOI: 10.15252/embj.2022112717] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 03/14/2023] Open
Abstract
Intracellular organization is largely mediated by actin turnover. Cellular actin networks continuously assemble and disassemble, while maintaining their overall appearance. This behavior, called "dynamic steady state," allows cells to sense and adapt to their environment. However, how structural stability can be maintained during the constant turnover of a limited actin monomer pool is poorly understood. To answer this question, we developed an experimental system where polystyrene beads are propelled by an actin comet in a microwell containing a limited amount of components. We used the speed and the size of the actin comet tails to evaluate the system's monomer consumption and its lifetime. We established the relative contribution of actin assembly, disassembly, and recycling for a bead movement over tens of hours. Recycling mediated by cyclase-associated protein (CAP) is the key step in allowing the reuse of monomers for multiple assembly cycles. ATP supply and protein aging are also factors that limit the lifetime of actin turnover. This work reveals the balancing mechanism for long-term network assembly with a limited amount of building blocks.
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Affiliation(s)
- Alexandra Colin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Tommi Kotila
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Christophe Guérin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Magali Orhant-Prioux
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France
| | - Benoit Vianay
- CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, NY, USA.,Department of Biology, New York University, New York, NY, USA
| | - Pekka Lappalainen
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Manuel Théry
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France.,CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
| | - Laurent Blanchoin
- CytoMorpho Lab, Laboratoire de Physiologie Cellulaire & Végétale, Interdisciplinary Research Institute of Grenoble, University of Grenoble-Alpes, CEA, CNRS, INRA, Grenoble, France.,CytoMorpho Lab, Institut de Recherche Saint Louis, U976 Human Immunology Pathophysiology Immunotherapy (HIPI), University of Paris, INSERM, CEA, Paris, France
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16
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Wang H, Luo Y, Ou S, Ni T, Chu Z, Feng X, Dai X, Zhang X, Liu Y. Celastrus orbiculatus Thunb. extract inhibits EMT and metastasis of gastric cancer by regulating actin cytoskeleton remodeling. JOURNAL OF ETHNOPHARMACOLOGY 2023; 301:115737. [PMID: 36179952 DOI: 10.1016/j.jep.2022.115737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The traditional Chinese medicine herb Celastrus orbiculatus Thunb. is an important folk medicinal plant in China that has been used as an anti-inflammatory, antitumor, and analgesic in various diseases. Recent years, many studies have reported the significant effects of Celastrus orbiculatus Thunb. extract (COE) on gastric cancer. However, the specific mechanism by which COE regulates gastric cancer cytoskeleton remodeling and thus inhibits EMT has not yet been reported. AIM OF STUDY To study the effect and mechanism of COE in inhibiting the epithelial-mesenchymal transition (EMT) and metastasis of gastric cancer cells, laying an experimental foundation for the clinical application and further development of COE. METHODS The high-content cell dynamic tracking system was used to continuously track the trajectory of cell movement in real time. Through the high-content data, the average movement distance and movement speed of the cells are calculated. Additionally, the dynamic images of the cell movement in the high-content imaging system are derived to analyze the impact of COE on the movement of gastric cancer cells. Cytoskeleton staining experiment was performed to detect the effect of COE on the assembly of gastric cancer cell cytoskeleton proteins. Western blot was employed to detect the changes of EMT and metastasis-related proteins in the gastric cancer cells treated by COE. The effect of COE on the key regulatory protein Cofilin-1 (CFL1) of cell movement was examined by Western blot and protein degradation experiment. The effect of COE on EMT and metastasis of the gastric cancer cells lacking CFL1 was assessed by a transwell assay. The in vivo inhibitory effect of COE on EMT and metastasis of gastric cancer was determined by the animal living image system. IHC assays were used to detect the levels of EMT-related proteins in COE reversal in vivo. RESULT The results showed that the movement distance and average movement speed of gastric cancer cells after COE treatment were significantly lower than those of the control group. Cytoskeleton staining experiments revealed that COE can significantly change the distribution of skeletal proteins in gastric cancer cells. Additionally, COE treatment significantly reduced the expression of Matrix metalloproteinases (MMP-2, MMP-9) and other proteins. Furthermore, COE can significantly accelerate the degradation of CFL1 protein, and both COE treatment and CFL1 deletion can significantly inhibit EMT and metastasis of gastric cancer cells. Lastly, the number of peritoneal metastases of gastric cancer cells was significantly reduced in animals after COE treatment. COE can reverse the levels of EMT-related proteins while reducing the expression levels of CFL1 protein in vivo. CONCLUSION COE can significantly inhibit EMT and metastasis of gastric cancer cells in vivo and in vitro. This effect may be achieved by reducing the stability of CFL1 and inhibiting the assembly of actin in gastric cancer cells.
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Affiliation(s)
- Haibo Wang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - YuanYuan Luo
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China.
| | - Shiya Ou
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Tengyang Ni
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Zewen Chu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Xinyi Feng
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Xiaojun Dai
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China; Yangzhou Hospital of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Xiaochun Zhang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China; Yangzhou Hospital of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
| | - Yanqing Liu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, 225001, PR China; The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou, 225001, PR China.
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17
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Xu Y, Duan J, Ji W, Liu C, Li X, Wu Q, Gao C, Su C. A novel matrine derivative, WM130, inhibits activation and movement of human hepatic stellate LX-2 cells by targeting cofilin 1. Cytotechnology 2022; 74:613-622. [PMID: 36389285 PMCID: PMC9652194 DOI: 10.1007/s10616-022-00548-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 08/23/2022] [Indexed: 11/26/2022] Open
Abstract
Matrine, one of the active ingredients of Sophora flavescens Ait., has a protective effect in animal models on acute liver injury and liver fibrosis. However, since the protective effects are short-lived, a structural modification of matrine is needed to improve its anti-fibrotic effects. In the previous study we obtained a stable, highly active new matrine derivative, WM130, and explored its anti-fibrotic effects on the human hepatic stellate cell line, LX-2. CCK-8, wound healing, and transwell assays were used to investigate cell proliferation and migration, while 3D mimic study was used to determine the target of WM130. Western blots investigated the levels of α-SMA, cofilin 1, p-cofilin 1, F-actin, PI3K, p-Akt, Akt, and PTEN in LX-2 cells treated with MW130. The results revealed that WM130 can significantly inhibit the proliferation of LX-2 cells at an IC50 of 60 μg/ml. At 30 µg/ml, matrine or WM130 significantly inhibited the migration of LX-2 cells. Moreover, WM130 significantly reduced the expression of α-SMA, cofilin 1, F-actin, PI3K, and p-Akt, and increased PTEN levels. In conclusion, WM130 inhibits the proliferation, activation, and migration of human hepatic stellate LX-2 cells by targeting cofilin 1. Supplementary Information The online version contains supplementary material available at 10.1007/s10616-022-00548-w.
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Affiliation(s)
- Yang Xu
- Clinical Laboratory Medicine Center, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437 China
- Department of Molecular Oncology, Eastern Hepatobiliary Surgery Hospital and National Center of Liver Cancer, Navy Military Medical University, Shanghai, 200438 China
| | - Jicheng Duan
- Department of Molecular Oncology, Eastern Hepatobiliary Surgery Hospital and National Center of Liver Cancer, Navy Military Medical University, Shanghai, 200438 China
| | - Weidan Ji
- Department of Molecular Oncology, Eastern Hepatobiliary Surgery Hospital and National Center of Liver Cancer, Navy Military Medical University, Shanghai, 200438 China
| | - Chao Liu
- Department of Pharmacy, Navy Military Medical University, Shanghai, 200438 China
| | - Xiang Li
- Department of Pharmacy, Navy Military Medical University, Shanghai, 200438 China
| | - Qiuye Wu
- Department of Pharmacy, Navy Military Medical University, Shanghai, 200438 China
| | - Chunfang Gao
- Clinical Laboratory Medicine Center, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437 China
| | - Changqing Su
- Department of Molecular Oncology, Eastern Hepatobiliary Surgery Hospital and National Center of Liver Cancer, Navy Military Medical University, Shanghai, 200438 China
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18
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Lappalainen P, Kotila T, Jégou A, Romet-Lemonne G. Biochemical and mechanical regulation of actin dynamics. Nat Rev Mol Cell Biol 2022; 23:836-852. [PMID: 35918536 DOI: 10.1038/s41580-022-00508-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/30/2022]
Abstract
Polymerization of actin filaments against membranes produces force for numerous cellular processes, such as migration, morphogenesis, endocytosis, phagocytosis and organelle dynamics. Consequently, aberrant actin cytoskeleton dynamics are linked to various diseases, including cancer, as well as immunological and neurological disorders. Understanding how actin filaments generate forces in cells, how force production is regulated by the interplay between actin-binding proteins and how the actin-regulatory machinery responds to mechanical load are at the heart of many cellular, developmental and pathological processes. During the past few years, our understanding of the mechanisms controlling actin filament assembly and disassembly has evolved substantially. It has also become evident that the activities of key actin-binding proteins are not regulated solely by biochemical signalling pathways, as mechanical regulation is critical for these proteins. Indeed, the architecture and dynamics of the actin cytoskeleton are directly tuned by mechanical load. Here we discuss the general mechanisms by which key actin regulators, often in synergy with each other, control actin filament assembly, disassembly, and monomer recycling. By using an updated view of actin dynamics as a framework, we discuss how the mechanics and geometry of actin networks control actin-binding proteins, and how this translates into force production in endocytosis and mesenchymal cell migration.
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Affiliation(s)
- Pekka Lappalainen
- Institute of Biotechnology and Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland.
| | - Tommi Kotila
- Institute of Biotechnology and Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland
| | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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19
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Jaswandkar SV, Katti KS, Katti DR. Molecular and structural basis of actin filament severing by ADF/cofilin. Comput Struct Biotechnol J 2022; 20:4157-4171. [PMID: 36016710 PMCID: PMC9379983 DOI: 10.1016/j.csbj.2022.07.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/30/2022] [Accepted: 07/31/2022] [Indexed: 12/04/2022] Open
Abstract
ADF/cofilin’s cooperative binding to actin filament modifies the conformation and alignment of G-actin subunits locally, causing the filament to sever at “boundaries” formed among bare and ADF/cofilin-occupied regions. Analysis of the impact of the ADF/cofilin cluster boundary on the deformation behavior of actin filaments in a mechanically strained environment is critical for understanding the biophysics of their severing. The present investigation uses molecular dynamics simulations to generate atomic resolution models of bare, partially, and fully cofilin decorated actin filaments. Steered molecular dynamics simulations are utilized to determine the mechanical properties of three filament models when subjected to axial stretching, axial compression, and bending forces. We highlight differences in strain distribution, failure mechanisms in the three filament models, and biomechanical effects of cofilin cluster boundaries in overall filament rupture. Based on the influence of ADF/cofilin binding on intrastrand and interstrand G-actin interfaces, the cofilin-mediated actin filament severing model proposed here can help understand cofilin mediated actin dynamics.
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20
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Kotila T, Wioland H, Selvaraj M, Kogan K, Antenucci L, Jégou A, Huiskonen JT, Romet-Lemonne G, Lappalainen P. Structural basis of rapid actin dynamics in the evolutionarily divergent Leishmania parasite. Nat Commun 2022; 13:3442. [PMID: 35705539 PMCID: PMC9200798 DOI: 10.1038/s41467-022-31068-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/01/2022] [Indexed: 11/08/2022] Open
Abstract
Actin polymerization generates forces for cellular processes throughout the eukaryotic kingdom, but our understanding of the 'ancient' actin turnover machineries is limited. We show that, despite > 1 billion years of evolution, pathogenic Leishmania major parasite and mammalian actins share the same overall fold and co-polymerize with each other. Interestingly, Leishmania harbors a simple actin-regulatory machinery that lacks cofilin 'cofactors', which accelerate filament disassembly in higher eukaryotes. By applying single-filament biochemistry we discovered that, compared to mammalian proteins, Leishmania actin filaments depolymerize more rapidly from both ends, and are severed > 100-fold more efficiently by cofilin. Our high-resolution cryo-EM structures of Leishmania ADP-, ADP-Pi- and cofilin-actin filaments identify specific features at actin subunit interfaces and cofilin-actin interactions that explain the unusually rapid dynamics of parasite actin filaments. Our findings reveal how divergent parasites achieve rapid actin dynamics using a remarkably simple set of actin-binding proteins, and elucidate evolution of the actin cytoskeleton.
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Affiliation(s)
- Tommi Kotila
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Hugo Wioland
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | - Muniyandi Selvaraj
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Konstantin Kogan
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Lina Antenucci
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | - Juha T Huiskonen
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | | | - Pekka Lappalainen
- Institute of Biotechnology and Helsinki Institute of Life Science, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.
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21
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Boiero Sanders M, Toret CP, Guillotin A, Antkowiak A, Vannier T, Robinson RC, Michelot A. Specialization of actin isoforms derived from the loss of key interactions with regulatory factors. EMBO J 2022; 41:e107982. [PMID: 35178724 PMCID: PMC8886540 DOI: 10.15252/embj.2021107982] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/09/2022] Open
Abstract
A paradox of eukaryotic cells is that while some species assemble a complex actin cytoskeleton from a single ortholog, other species utilize a greater diversity of actin isoforms. The physiological consequences of using different actin isoforms, and the molecular mechanisms by which highly conserved actin isoforms are segregated into distinct networks, are poorly known. Here, we sought to understand how a simple biological system, composed of a unique actin and a limited set of actin‐binding proteins, reacts to a switch to heterologous actin expression. Using yeast as a model system and biomimetic assays, we show that such perturbation causes drastic reorganization of the actin cytoskeleton. Our results indicate that defective interaction of a heterologous actin for important regulators of actin assembly limits certain actin assembly pathways while reinforcing others. Expression of two heterologous actin variants, each specialized in assembling a different network, rescues cytoskeletal organization and confers resistance to external perturbation. Hence, while species using a unique actin have homeostatic actin networks, actin assembly pathways in species using several actin isoforms may act more independently.
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Affiliation(s)
| | - Christopher P Toret
- CNRS, IBDM, Turing Centre for Living Systems, Aix Marseille Univ, Marseille, France
| | - Audrey Guillotin
- CNRS, IBDM, Turing Centre for Living Systems, Aix Marseille Univ, Marseille, France
| | - Adrien Antkowiak
- CNRS, IBDM, Turing Centre for Living Systems, Aix Marseille Univ, Marseille, France
| | - Thomas Vannier
- CNRS, IBDM, Turing Centre for Living Systems, Aix Marseille Univ, Marseille, France
| | - Robert C Robinson
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama, Japan.,School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Alphée Michelot
- CNRS, IBDM, Turing Centre for Living Systems, Aix Marseille Univ, Marseille, France
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22
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Abstract
The precise assembly and disassembly of actin filaments is required for several cellular processes, and their regulation has been scrutinized for decades. Twenty years ago, a handful of studies marked the advent of a new type of experiment to study actin dynamics: using optical microscopy to look at individual events, taking place on individual filaments in real time. Here, we summarize the main characteristics of this approach and how it has changed our ability to understand actin assembly dynamics. We also highlight some of its caveats and reflect on what we have learned over the past 20 years, leading us to propose a set of guidelines, which we hope will contribute to a better exploitation of this powerful tool.
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23
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Sherer LA, Courtemanche N. Cooperative bundling by fascin generates actin structures with architectures that depend on filament length. Front Cell Dev Biol 2022; 10:974047. [PMID: 36120572 PMCID: PMC9479110 DOI: 10.3389/fcell.2022.974047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/12/2022] [Indexed: 11/30/2022] Open
Abstract
The assembly of actin-based structures with precisely defined architectures supports essential cellular functions, including motility, intracellular transport, and division. The geometric arrangements of the filaments within actin structures are stabilized via the association of crosslinking proteins, which bind two filaments simultaneously. Because actin polymerization and crosslinking occur concurrently within the dynamic environment of the cell, these processes likely play interdependent roles in shaping the architectures of actin-based structures. To dissect the contribution of polymerization to the construction of higher-order actin structures, we investigated how filament elongation affects the formation of simple, polarized actin bundles by the crosslinking protein fascin. Using populations of actin filaments to represent distinct stages of elongation, we found that the rate of bundle assembly increases with filament length. Fascin assembles short filaments into discrete bundles, whereas bundles of long filaments merge with one another to form interconnected networks. Although filament elongation promotes bundle coalescence, many connections formed between elongating bundles are short-lived and are followed by filament breakage. Our data suggest that initiation of crosslinking early in elongation aligns growing filaments, creating a template for continued bundle assembly as elongation proceeds. This initial alignment promotes the assembly of bundles that are resistant to large changes in curvature that are required for coalescence into interconnected networks. As a result, bundles of short filaments remain straighter and more topologically discrete as elongation proceeds than bundles assembled from long filaments. Thus, uncoordinated filament elongation and crosslinking can alter the architecture of bundled actin networks, highlighting the importance of maintaining precise control over filament length during the assembly of specialized actin structures.
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Bourdais A, Dehapiot B, Halet G. Cofilin regulates actin network homeostasis and microvilli length in mouse oocytes. J Cell Sci 2021; 134:273797. [PMID: 34841429 DOI: 10.1242/jcs.259237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/18/2021] [Indexed: 11/20/2022] Open
Abstract
How multiple actin networks coexist in a common cytoplasm while competing for a shared pool of monomers is still an ongoing question. This is exemplified by meiotic maturation in the mouse oocyte, which relies on the dynamic remodeling of distinct cortical and cytoplasmic F-actin networks. Here, we show that the conserved actin-depolymerizing factor cofilin is activated in a switch-like manner upon meiosis resumption from prophase arrest. Interfering with cofilin activation during maturation resulted in widespread elongation of microvilli, while cytoplasmic F-actin was depleted, leading to defects in spindle migration and polar body extrusion. In contrast, cofilin inactivation in metaphase II-arrested oocytes resulted in a shutdown of F-actin dynamics, along with a dramatic overgrowth of the polarized actin cap. However, inhibition of the Arp2/3 complex to promote actin cap disassembly elicited ectopic microvilli outgrowth in the polarized cortex. These data establish cofilin as a key player in actin network homeostasis in oocytes and reveal that microvilli can act as a sink for monomers upon disassembly of a competing network.
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Affiliation(s)
- Anne Bourdais
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Benoit Dehapiot
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Guillaume Halet
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
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25
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Kadzik RS, Homa KE, Kovar DR. F-Actin Cytoskeleton Network Self-Organization Through Competition and Cooperation. Annu Rev Cell Dev Biol 2021; 36:35-60. [PMID: 33021819 DOI: 10.1146/annurev-cellbio-032320-094706] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many fundamental cellular processes such as division, polarization, endocytosis, and motility require the assembly, maintenance, and disassembly of filamentous actin (F-actin) networks at specific locations and times within the cell. The particular function of each network is governed by F-actin organization, size, and density as well as by its dynamics. The distinct characteristics of different F-actin networks are determined through the coordinated actions of specific sets of actin-binding proteins (ABPs). Furthermore, a cell typically assembles and uses multiple F-actin networks simultaneously within a common cytoplasm, so these networks must self-organize from a common pool of shared globular actin (G-actin) monomers and overlapping sets of ABPs. Recent advances in multicolor imaging and analysis of ABPs and their associated F-actin networks in cells, as well as the development of sophisticated in vitro reconstitutions of networks with ensembles of ABPs, have allowed the field to start uncovering the underlying principles by which cells self-organize diverse F-actin networks to execute basic cellular functions.
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Affiliation(s)
- Rachel S Kadzik
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; , .,Department of Molecular BioSciences, Northwestern University, Evanston, Illinois 60208, USA;
| | - Kaitlin E Homa
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; ,
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA; , .,Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
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Ullo MF, Logue JS. ADF and cofilin-1 collaborate to promote cortical actin flow and the leader bleb-based migration of confined cells. eLife 2021; 10:67856. [PMID: 34169836 PMCID: PMC8253594 DOI: 10.7554/elife.67856] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/22/2021] [Indexed: 01/16/2023] Open
Abstract
Melanoma cells have been shown to undergo fast amoeboid (leader bleb-based) migration, requiring a single large bleb for migration. In leader blebs, is a rapid flow of cortical actin that drives the cell forward. Using RNAi, we find that co-depleting cofilin-1 and actin depolymerizing factor (ADF) led to a large increase in cortical actin, suggesting that both proteins regulate cortical actin. Furthermore, severing factors can promote contractility through the regulation of actin architecture. However, RNAi of cofilin-1 but not ADF led to a significant decrease in cell stiffness. We found cofilin-1 to be enriched at leader bleb necks, whereas RNAi of cofilin-1 and ADF reduced bleb sizes and the frequency of motile cells. Strikingly, cells without cofilin-1 and ADF had blebs with abnormally long necks. Many of these blebs failed to retract and displayed slow actin turnover. Collectively, our data identifies cofilin-1 and ADF as actin remodeling factors required for fast amoeboid migration.
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Affiliation(s)
- Maria F Ullo
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Jeremy S Logue
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
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27
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Bolger-Munro M, Choi K, Cheung F, Liu YT, Dang-Lawson M, Deretic N, Keane C, Gold MR. The Wdr1-LIMK-Cofilin Axis Controls B Cell Antigen Receptor-Induced Actin Remodeling and Signaling at the Immune Synapse. Front Cell Dev Biol 2021; 9:649433. [PMID: 33928084 PMCID: PMC8076898 DOI: 10.3389/fcell.2021.649433] [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: 01/04/2021] [Accepted: 03/12/2021] [Indexed: 12/27/2022] Open
Abstract
When B cells encounter membrane-bound antigens, the formation and coalescence of B cell antigen receptor (BCR) microclusters amplifies BCR signaling. The ability of B cells to probe the surface of antigen-presenting cells (APCs) and respond to APC-bound antigens requires remodeling of the actin cytoskeleton. Initial BCR signaling stimulates actin-related protein (Arp) 2/3 complex-dependent actin polymerization, which drives B cell spreading as well as the centripetal movement and coalescence of BCR microclusters at the B cell-APC synapse. Sustained actin polymerization depends on concomitant actin filament depolymerization, which enables the recycling of actin monomers and Arp2/3 complexes. Cofilin-mediated severing of actin filaments is a rate-limiting step in the morphological changes that occur during immune synapse formation. Hence, regulators of cofilin activity such as WD repeat-containing protein 1 (Wdr1), LIM domain kinase (LIMK), and coactosin-like 1 (Cotl1) may also be essential for actin-dependent processes in B cells. Wdr1 enhances cofilin-mediated actin disassembly. Conversely, Cotl1 competes with cofilin for binding to actin and LIMK phosphorylates cofilin and prevents it from binding to actin filaments. We now show that Wdr1 and LIMK have distinct roles in BCR-induced assembly of the peripheral actin structures that drive B cell spreading, and that cofilin, Wdr1, and LIMK all contribute to the actin-dependent amplification of BCR signaling at the immune synapse. Depleting Cotl1 had no effect on these processes. Thus, the Wdr1-LIMK-cofilin axis is critical for BCR-induced actin remodeling and for B cell responses to APC-bound antigens.
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Affiliation(s)
- Madison Bolger-Munro
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kate Choi
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Faith Cheung
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Yi Tian Liu
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - May Dang-Lawson
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Nikola Deretic
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Connor Keane
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Gold
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
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Lipid Rafts Interaction of the ARID3A Transcription Factor with EZRIN and G-Actin Regulates B-Cell Receptor Signaling. Diseases 2021; 9:diseases9010022. [PMID: 33804610 PMCID: PMC8005928 DOI: 10.3390/diseases9010022] [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: 02/10/2021] [Revised: 03/12/2021] [Accepted: 03/18/2021] [Indexed: 11/17/2022] Open
Abstract
Several diseases originate via dysregulation of the actin cytoskeleton. The ARID3A/Bright transcription factor has also been implicated in malignancies, primarily those derived from hematopoietic lineages. Previously, we demonstrated that ARID3A shuttles between the nucleus and the plasma membrane, where it localizes within lipid rafts. There it interacts with components of the B-cell receptor (BCR) to reduce its ability to transmit downstream signaling. We demonstrate here that a direct component of ARID3A-regulated BCR signal strength is cortical actin. ARID3A interacts with actin exclusively within lipid rafts via the actin-binding protein EZRIN, which confines unstimulated BCRs within lipid rafts. BCR ligation discharges the ARID3A-EZRIN complex from lipid rafts, allowing the BCR to initiate downstream signaling events. The ARID3A-EZRIN interaction occurs almost exclusively within unpolymerized G-actin, where EZRIN interacts with the multifunctional ARID3A REKLES domain. These observations provide a mechanism by which a transcription factor directly regulates BCR signaling via linkage to the actin cytoskeleton with consequences for B-cell-related neoplasia.
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Zhang L, Chai Z, Kong S, Feng J, Wu M, Tan J, Yuan M, Chen G, Li Z, Zhou H, Cheng S, Xu H. Nujiangexanthone A Inhibits Hepatocellular Carcinoma Metastasis via Down Regulation of Cofilin 1. Front Cell Dev Biol 2021; 9:644716. [PMID: 33791303 PMCID: PMC8006445 DOI: 10.3389/fcell.2021.644716] [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: 12/21/2020] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the malignant tumors with poor prognosis. High expression level of cofilin 1 (CFL1) has been found in many types of cancers. However, the role of CFL1 in HCC hasn’t been known clearly. Here, we found that CFL1 was up regulated in human HCC and significantly associated with both overall survival and disease-free survival in HCC patients. Nujiangexanthone A (NJXA), the caged xanthones, isolated from gamboge plants decreased the expression of CFL1, which also inhibited the migration, invasion and metastasis of HCC cells in vitro and in vivo. Down regulation of CFL1 inhibited aggressiveness of HCC cells, which mimicked the effect of NJXA. Mechanism study indicated that, knockdown of CFL1 or treatment with NJXA increased the level of F-actin and disturbed the balance between F-actin and G-actin. In conclusion, our findings reveal the role of CFL1 in HCC metastasis through the CFL1/F-actin axis, and suggest that CFL1 may be a potential prognostic marker and a new therapeutic target. NJXA can effectively inhibit the metastasis of HCC cells by down regulating the expression of CFL1, which indicates the potential of NJXA for preventing metastasis in HCC.
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Affiliation(s)
- Li Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zongtao Chai
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Siyuan Kong
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiling Feng
- Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Man Wu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiaqi Tan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Man Yuan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Gan Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhuo Li
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hua Zhou
- Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shuqun Cheng
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Hongxi Xu
- Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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30
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Bibeau JP, Gray S, De La Cruz EM. Clusters of a Few Bound Cofilins Sever Actin Filaments. J Mol Biol 2021; 433:166833. [PMID: 33524412 DOI: 10.1016/j.jmb.2021.166833] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/06/2023]
Abstract
Cofilin is an essential actin filament severing protein that accelerates the assembly dynamics and turnover of actin networks by increasing the number of filament ends where subunits add and dissociate. It binds filament subunits stoichiometrically and cooperatively, forming clusters of contiguously-bound cofilin at sub-saturating occupancies. Filaments partially occupied with cofilin sever at boundaries between bare and cofilin-decorated segments. Imaging studies concluded that bound clusters must reach a critical size (Cc) of 13-100 cofilins to sever filaments. In contrast, structural and modeling studies suggest that a few or even a single cofilin can sever filaments, possibly with different severing rate constants. How clusters grow through the cooperative incorporation of additional cofilin molecules, specifically if they elongate asymmetrically or uniformly from both ends and if they are modulated by filament shape and external force, also lacks consensus. Here, using hydrodynamic flow to visualize individual actin filaments with TIRF microscopy, we found that neither flow-induced filament bending, tension, nor surface attachment conditions substantially affected the kinetics of cofilin binding to actin filaments. Clusters of bound cofilin preferentially extended toward filament pointed ends and displayed severing competency at small sizes (Cc < 3), with no detectable severing dependence on cluster size. These data support models in which small clusters of cofilin introduce local, but asymmetric, structural changes in actin filaments that promote filament severing with a rate constant that depends weakly on the size of the cluster.
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Affiliation(s)
- Jeffrey P Bibeau
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, United States
| | - Shawn Gray
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, United States
| | - Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, United States.
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31
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Wioland H, Frémont S, Guichard B, Echard A, Jégou A, Romet-Lemonne G. Actin filament oxidation by MICAL1 suppresses protections from cofilin-induced disassembly. EMBO Rep 2021; 22:e50965. [PMID: 33393173 DOI: 10.15252/embr.202050965] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/18/2020] [Accepted: 11/27/2020] [Indexed: 02/01/2023] Open
Abstract
Proteins of the ADF/cofilin family play a central role in the disassembly of actin filaments, and their activity must be tightly regulated in cells. Recently, the oxidation of actin filaments by the enzyme MICAL1 was found to amplify the severing action of cofilin through unclear mechanisms. Using single filament experiments in vitro, we found that actin filament oxidation by MICAL1 increases, by several orders of magnitude, both cofilin binding and severing rates, explaining the dramatic synergy between oxidation and cofilin for filament disassembly. Remarkably, we found that actin oxidation bypasses the need for cofilin activation by dephosphorylation. Indeed, non-activated, phosphomimetic S3D-cofilin binds and severs oxidized actin filaments rapidly, in conditions where non-oxidized filaments are unaffected. Finally, tropomyosin Tpm1.8 loses its ability to protect filaments from cofilin severing activity when actin is oxidized by MICAL1. Together, our results show that MICAL1-induced oxidation of actin filaments suppresses their physiological protection from the action of cofilin. We propose that, in cells, direct post-translational modification of actin filaments by oxidation is a way to trigger their disassembly.
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Affiliation(s)
- Hugo Wioland
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
| | - Stéphane Frémont
- Membrane Traffic and Cell Division Lab, Institut Pasteur, UMR3691, CNRS, Paris, France
| | | | - Arnaud Echard
- Membrane Traffic and Cell Division Lab, Institut Pasteur, UMR3691, CNRS, Paris, France
| | - Antoine Jégou
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
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32
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Smith CEL, Lake AVR, Johnson CA. Primary Cilia, Ciliogenesis and the Actin Cytoskeleton: A Little Less Resorption, A Little More Actin Please. Front Cell Dev Biol 2020; 8:622822. [PMID: 33392209 PMCID: PMC7773788 DOI: 10.3389/fcell.2020.622822] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Primary cilia are microtubule-based organelles that extend from the apical surface of most mammalian cells, forming when the basal body (derived from the mother centriole) docks at the apical cell membrane. They act as universal cellular "antennae" in vertebrates that receive and integrate mechanical and chemical signals from the extracellular environment, serving diverse roles in chemo-, mechano- and photo-sensation that control developmental signaling, cell polarity and cell proliferation. Mutations in ciliary genes cause a major group of inherited developmental disorders called ciliopathies. There are very few preventative treatments or new therapeutic interventions that modify disease progression or the long-term outlook of patients with these conditions. Recent work has identified at least four distinct but interrelated cellular processes that regulate cilia formation and maintenance, comprising the cell cycle, cellular proteostasis, signaling pathways and structural influences of the actin cytoskeleton. The actin cytoskeleton is composed of microfilaments that are formed from filamentous (F) polymers of globular G-actin subunits. Actin filaments are organized into bundles and networks, and are attached to the cell membrane, by diverse cross-linking proteins. During cell migration, actin filament bundles form either radially at the leading edge or as axial stress fibers. Early studies demonstrated that loss-of-function mutations in ciliopathy genes increased stress fiber formation and impaired ciliogenesis whereas pharmacological inhibition of actin polymerization promoted ciliogenesis. These studies suggest that polymerization of the actin cytoskeleton, F-actin branching and the formation of stress fibers all inhibit primary cilium formation, whereas depolymerization or depletion of actin enhance ciliogenesis. Here, we review the mechanistic basis for these effects on ciliogenesis, which comprise several cellular processes acting in concert at different timescales. Actin polymerization is both a physical barrier to both cilia-targeted vesicle transport and to the membrane remodeling required for ciliogenesis. In contrast, actin may cause cilia loss by localizing disassembly factors at the ciliary base, and F-actin branching may itself activate the YAP/TAZ pathway to promote cilia disassembly. The fundamental role of actin polymerization in the control of ciliogenesis may present potential new targets for disease-modifying therapeutic approaches in treating ciliopathies.
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Affiliation(s)
| | | | - Colin A. Johnson
- Leeds Institute of Medical Research at St. James’s, University of Leeds, Leeds, United Kingdom
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Liebman C, McColloch A, Rabiei M, Bowling A, Cho M. Mechanics of the cell: Interaction mechanisms and mechanobiological models. CURRENT TOPICS IN MEMBRANES 2020; 86:143-184. [PMID: 33837692 DOI: 10.1016/bs.ctm.2020.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The importance of cell mechanics has long been recognized for the cell development and function. Biomechanics plays an important role in cell metabolism, regulation of mechanotransduction pathways and also modulation of nuclear response. The mechanical properties of the cell are likely determined by, among many others, the cytoskeleton elasticity, membrane tension and cell-substrate adhesion. This coordinated but complex mechanical interplay is required however, for the cell to respond to and influence in a reciprocal manner the chemical and mechanical signals from the extracellular matrix (ECM). In an effort to better and more fully understand the cell mechanics, the role of nuclear mechanics has emerged as an important contributor to the overall cellular mechanics. It is not too difficult to appreciate the physical connection between the nucleus and the cytoskeleton network that may be connected to the ECM through the cell membrane. Transmission of forces from ECM through this connection is essential for a wide range of cellular behaviors and functions such as cytoskeletal reorganization, nuclear movement, cell migration and differentiation. Unlike the cellular mechanics that can be measured using a number of biophysical techniques that were developed in the past few decades, it still remains a daunting challenge to probe the nuclear mechanics directly. In this paper, we therefore aim to provide informative description of the cell membrane and cytoskeleton mechanics, followed by unique computational modeling efforts to elucidate the nucleus-cytoskeleton coupling. Advances in our knowledge of complete cellular biomechanics and mechanotransduction may lead to clinical relevance and applications in mechano-diseases such as atherosclerosis, stem cell-based therapies, and the development of tissue engineered products.
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Affiliation(s)
- Caleb Liebman
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, United States
| | - Andrew McColloch
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, United States
| | - Manoochehr Rabiei
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX, United States
| | - Alan Bowling
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX, United States.
| | - Michael Cho
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, United States.
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Boiero Sanders M, Antkowiak A, Michelot A. Diversity from similarity: cellular strategies for assigning particular identities to actin filaments and networks. Open Biol 2020; 10:200157. [PMID: 32873155 PMCID: PMC7536088 DOI: 10.1098/rsob.200157] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The actin cytoskeleton has the particularity of being assembled into many functionally distinct filamentous networks from a common reservoir of monomeric actin. Each of these networks has its own geometrical, dynamical and mechanical properties, because they are capable of recruiting specific families of actin-binding proteins (ABPs), while excluding the others. This review discusses our current understanding of the underlying molecular mechanisms that cells have developed over the course of evolution to segregate ABPs to appropriate actin networks. Segregation of ABPs requires the ability to distinguish actin networks as different substrates for ABPs, which is regulated in three different ways: (1) by the geometrical organization of actin filaments within networks, which promotes or inhibits the accumulation of ABPs; (2) by the identity of the networks' filaments, which results from the decoration of actin filaments with additional proteins such as tropomyosin, from the use of different actin isoforms or from covalent modifications of actin; (3) by the existence of collaborative or competitive binding to actin filaments between two or multiple ABPs. This review highlights that all these effects need to be taken into account to understand the proper localization of ABPs in cells, and discusses what remains to be understood in this field of research.
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Affiliation(s)
- Micaela Boiero Sanders
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Adrien Antkowiak
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Alphée Michelot
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
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35
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Insights into the evolution of regulated actin dynamics via characterization of primitive gelsolin/cofilin proteins from Asgard archaea. Proc Natl Acad Sci U S A 2020; 117:19904-19913. [PMID: 32747565 PMCID: PMC7444086 DOI: 10.1073/pnas.2009167117] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Eukaryotic gelsolin superfamily proteins generally comprise three or more related domains. Here we characterize single- and double-domain gelsolins from Thorarchaeota (Thor). Similar domain architectures are present in Heimdall-, Loki-, and Odinarchaeota. Thor gelsolins are functional in regulating rabbit actin in in vitro assays, showing a range of activities including actin filament severing and bundling. These gelsolins bind to the eukaryotic gelsolin/cofilin-binding site on actin. Two-domain, but not one-domain, gelsolins are calcium regulated. Thor gelsolins appear to have the characteristics and structure consistent with primitive gelsolins/cofilins, suggesting that these single- and double-domain gelsolins are a record of a nascent preeukaryotic actin-regulation machinery. Asgard archaea genomes contain potential eukaryotic-like genes that provide intriguing insight for the evolution of eukaryotes. The eukaryotic actin polymerization/depolymerization cycle is critical for providing force and structure in many processes, including membrane remodeling. In general, Asgard genomes encode two classes of actin-regulating proteins from sequence analysis, profilins and gelsolins. Asgard profilins were demonstrated to regulate actin filament nucleation. Here, we identify actin filament severing, capping, annealing and bundling, and monomer sequestration activities by gelsolin proteins from Thorarchaeota (Thor), which complete a eukaryotic-like actin depolymerization cycle, and indicate complex actin cytoskeleton regulation in Asgard organisms. Thor gelsolins have homologs in other Asgard archaea and comprise one or two copies of the prototypical gelsolin domain. This appears to be a record of an initial preeukaryotic gene duplication event, since eukaryotic gelsolins are generally comprise three to six domains. X-ray structures of these proteins in complex with mammalian actin revealed similar interactions to the first domain of human gelsolin or cofilin with actin. Asgard two-domain, but not one-domain, gelsolins contain calcium-binding sites, which is manifested in calcium-controlled activities. Expression of two-domain gelsolins in mammalian cells enhanced actin filament disassembly on ionomycin-triggered calcium release. This functional demonstration, at the cellular level, provides evidence for a calcium-controlled Asgard actin cytoskeleton, indicating that the calcium-regulated actin cytoskeleton predates eukaryotes. In eukaryotes, dynamic bundled actin filaments are responsible for shaping filopodia and microvilli. By correlation, we hypothesize that the formation of the protrusions observed from Lokiarchaeota cell bodies may involve the gelsolin-regulated actin structures.
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36
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Bleicher P, Sciortino A, Bausch AR. The dynamics of actin network turnover is self-organized by a growth-depletion feedback. Sci Rep 2020; 10:6215. [PMID: 32277095 PMCID: PMC7148320 DOI: 10.1038/s41598-020-62942-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/24/2020] [Indexed: 01/22/2023] Open
Abstract
The dynamics of actin networks is modulated by a machinery consisting of actin binding proteins that control the turnover of filaments in space and time. To study this complex orchestration, in vitro reconstitution approaches strive to project actin dynamics in ideal, minimal systems. To this extent we reconstitute a self-supplying, dense network of globally treadmilling filaments. In this system we analyze growth and intrinsic turnover by means of FRAP measurements and thereby demonstrate how the depletion of monomers and actin binding partners modulate the dynamics in active actin networks. The described effects occur only in dense networks, as single filament dynamics are unable to produce depletion effects to this extent. Furthermore, we demonstrate a synergistic relationship between the nucleators formin and Arp2/3 when branched networks and formin-induced networks are colocalized. As a result, the formin-enhanced filament turnover depletes cofilin at the surface and thus protects the dense, Arp2/3 polymerized network from debranching. Ultimately, these results may be key for understanding the maintenance of the two contradicting requirements of network stability and dynamics in cells.
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Affiliation(s)
- P Bleicher
- Lehrstuhl für Biophysik E27, Physik-Department, Technische Universität München, Garching, Germany
| | - A Sciortino
- Lehrstuhl für Biophysik E27, Physik-Department, Technische Universität München, Garching, Germany
| | - A R Bausch
- Lehrstuhl für Biophysik E27, Physik-Department, Technische Universität München, Garching, Germany.
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37
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Pathak S, Tripathi S, Deori N, Ahmad B, Verma H, Lokhande R, Nagotu S, Kale A. Effect of tetracycline family of antibiotics on actin aggregation, resulting in the formation of Hirano bodies responsible for neuropathological disorders. J Biomol Struct Dyn 2020; 39:236-253. [PMID: 31948361 DOI: 10.1080/07391102.2020.1717629] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Actin, an ATPase superfamily protein, regulates some vital biological functions like cell locomotion, cytokinesis, synaptic plasticity and cell signaling in higher eukaryotes, and is dependent on the dynamics of actin polymerization process. Impaired regulation of actin polymerization has been implicated in the formation and deposition of rod-like paracrystalline structures called as Hirano bodies in neuronal cells of patients suffering from Alzheimer's disease, Pick's disease, Guam amyotrophic lateral sclerosis and parkinsonism-dementia complex. Aggregation of actin forming amorphous deposition in the brain cells is also associated with chronic alcoholism and aging of the neurons. In the current article, we propose the breaking of the highly amorphous and dysregulated actin aggregates using generic compounds like tetracycline, oxytetracycline, doxycycline and minocycline which are used as antibiotics against tuberculosis and infection caused due to various Gram-negative bacteria. We have investigated the effect and affinity of binding of these four compounds to that of actin aggregates using 90° light scattering, size exclusion chromatography, dynamic light scattering, circular dichroism, scanning electron microscopy, transmission electron microscopy imaging and kinetic analysis. The isothermal calorimetric measurements showed that the binding constant for the cycline family molecules used in this study range from 9.8 E4 M-1 to 1.3 E4 M-1. To understand the in vivo effect, we also studied the effect of these drugs on Saccharomyces cerevisiae Δend3 mutant cells. Our data suggest that these generic compounds can plausibly be used for the treatment of various neurodegenerative diseases occurring due to Hirano body formation in brain cells.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Samridhi Pathak
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
| | - Sarita Tripathi
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
| | - Nayan Deori
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Basir Ahmad
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India.,Protein Assembly Laboratory, JH-Institute of Molecular Medicine, New Delhi, India
| | - Hriday Verma
- School of Life Sciences, Jaipur National University, Jaipur, Rajasthan, India
| | - Rama Lokhande
- School of Life Sciences, Jaipur National University, Jaipur, Rajasthan, India
| | - Shirisha Nagotu
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Avinash Kale
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
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38
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Structures of cofilin-induced structural changes reveal local and asymmetric perturbations of actin filaments. Proc Natl Acad Sci U S A 2020; 117:1478-1484. [PMID: 31900364 DOI: 10.1073/pnas.1915987117] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Members of the cofilin/ADF family of proteins sever actin filaments, increasing the number of filament ends available for polymerization or depolymerization. Cofilin binds actin filaments with positive cooperativity, forming clusters of contiguously bound cofilin along the filament lattice. Filament severing occurs preferentially at boundaries between bare and cofilin-decorated (cofilactin) segments and is biased at 1 side of a cluster. A molecular understanding of cooperative binding and filament severing has been impeded by a lack of structural data describing boundaries. Here, we apply methods for analyzing filament cryo-electron microscopy (cryo-EM) data at the single subunit level to directly investigate the structure of boundaries within partially decorated cofilactin filaments. Subnanometer resolution maps of isolated, bound cofilin molecules and an actin-cofilactin boundary indicate that cofilin-induced actin conformational changes are local and limited to subunits directly contacting bound cofilin. An isolated, bound cofilin compromises longitudinal filament contacts of 1 protofilament, consistent with a single cofilin having filament-severing activity. An individual, bound phosphomimetic (S3D) cofilin with weak severing activity adopts a unique binding mode that does not perturb actin structure. Cofilin clusters disrupt both protofilaments, consistent with a higher severing activity at boundaries compared to single cofilin. Comparison of these structures indicates that this disruption is substantially greater at pointed end sides of cofilactin clusters than at the barbed end. These structures, with the distribution of bound cofilin clusters, suggest that maximum binding cooperativity is achieved when 2 cofilins occupy adjacent sites. These results reveal the structural origins of cooperative cofilin binding and actin filament severing.
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39
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Janssen E, Geha RS. Primary immunodeficiencies caused by mutations in actin regulatory proteins. Immunol Rev 2019; 287:121-134. [PMID: 30565251 DOI: 10.1111/imr.12716] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 08/31/2018] [Indexed: 12/31/2022]
Abstract
The identification of patients with monogenic gene defects have illuminated the function of different proteins in the immune system, including proteins that regulate the actin cytoskeleton. Many of these actin regulatory proteins are exclusively expressed in leukocytes and regulate the formation and branching of actin filaments. Their absence or abnormal function leads to defects in immune cell shape, cellular projections, migration, and signaling. Through the study of patients' mutations and generation of mouse models that recapitulate the patients' phenotypes, our laboratory and others have gained a better understanding of the role these proteins play in cell biology and the underlying pathogenesis of immunodeficiencies and immune dysregulatory syndromes.
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Affiliation(s)
- Erin Janssen
- Division of Immunology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Raif S Geha
- Division of Immunology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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40
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Abstract
Actin polymerization is essential for cells to migrate, as well as for various cell biological processes such as cytokinesis and vesicle traffic. This brief review describes the mechanisms underlying its different roles and recent advances in our understanding. Actin usually requires "nuclei"-preformed actin filaments-to start polymerizing, but, once initiated, polymerization continues constitutively. The field therefore has a strong focus on nucleators, in particular the Arp2/3 complex and formins. These have different functions, are controlled by contrasting mechanisms, and generate alternate geometries of actin networks. The Arp2/3 complex functions only when activated by nucleation-promoting factors such as WASP, Scar/WAVE, WASH, and WHAMM and when binding to a pre-existing filament. Formins can be individually active but are usually autoinhibited. Each is controlled by different mechanisms and is involved in different biological roles. We also describe the processes leading to actin disassembly and their regulation and conclude with four questions whose answers are important for understanding actin dynamics but are currently unanswered.
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Affiliation(s)
- Simona Buracco
- Institute of Cancer Sciences, University of Glasgow, Bearsden, G61 1BD, UK
| | - Sophie Claydon
- Institute of Cancer Sciences, University of Glasgow, Bearsden, G61 1BD, UK
| | - Robert Insall
- Institute of Cancer Sciences, University of Glasgow, Bearsden, G61 1BD, UK
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41
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Bowes C, Redd M, Yousfi M, Tauzin M, Murayama E, Herbomel P. Coronin 1A depletion restores the nuclear stability and viability of Aip1/Wdr1-deficient neutrophils. J Cell Biol 2019; 218:3258-3271. [PMID: 31471458 PMCID: PMC6781450 DOI: 10.1083/jcb.201901024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 06/20/2019] [Accepted: 07/01/2019] [Indexed: 12/21/2022] Open
Abstract
Bowes et al. show that in zebrafish embryos deficient in the cofilin cofactor AIP1/Wdr1, neutrophils display F-actin as cytoplasmic aggregates, spatially uncoupled from active myosin, then undergo a progressive unwinding of their nucleus followed by eruptive cell death. This adverse phenotype is fully rescued by depletion of another cofilin cofactor, coronin 1A. Actin dynamics is central for cells, and especially for the fast-moving leukocytes. The severing of actin filaments is mainly achieved by cofilin, assisted by Aip1/Wdr1 and coronins. We found that in Wdr1-deficient zebrafish embryos, neutrophils display F-actin cytoplasmic aggregates and a complete spatial uncoupling of phospho-myosin from F-actin. They then undergo an unprecedented gradual disorganization of their nucleus followed by eruptive cell death. Their cofilin is mostly unphosphorylated and associated with F-actin, thus likely outcompeting myosin for F-actin binding. Myosin inhibition reproduces in WT embryos the nuclear instability and eruptive death of neutrophils seen in Wdr1-deficient embryos. Strikingly, depletion of the main coronin of leukocytes, coronin 1A, fully restores the cortical location of F-actin, nuclear integrity, viability, and mobility of Wdr1-deficient neutrophils in vivo. Our study points to an essential role of actomyosin contractility in maintaining the integrity of the nucleus of neutrophils and a new twist in the interplay of cofilin, Wdr1, and coronin in regulating F-actin dynamics.
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Affiliation(s)
- Charnese Bowes
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris, France.,Centre National de la Recherche Scientifique, UMR3738, Paris, France
| | - Michael Redd
- University of Utah, Huntsman Cancer Institute, Salt Lake City, UT
| | - Malika Yousfi
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris, France.,Centre National de la Recherche Scientifique, UMR3738, Paris, France
| | - Muriel Tauzin
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris, France.,Centre National de la Recherche Scientifique, UMR3738, Paris, France
| | - Emi Murayama
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris, France.,Centre National de la Recherche Scientifique, UMR3738, Paris, France
| | - Philippe Herbomel
- Institut Pasteur, Department of Developmental and Stem Cell Biology, Paris, France .,Centre National de la Recherche Scientifique, UMR3738, Paris, France
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42
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ADF/cofilin regulation from a structural viewpoint. J Muscle Res Cell Motil 2019; 41:141-151. [DOI: 10.1007/s10974-019-09546-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/17/2019] [Indexed: 01/11/2023]
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43
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Sizes of actin networks sharing a common environment are determined by the relative rates of assembly. PLoS Biol 2019; 17:e3000317. [PMID: 31181075 PMCID: PMC6586355 DOI: 10.1371/journal.pbio.3000317] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 06/20/2019] [Accepted: 05/28/2019] [Indexed: 12/31/2022] Open
Abstract
Within the cytoplasm of a single cell, several actin networks can coexist with distinct sizes, geometries, and protein compositions. These actin networks assemble in competition for a limited pool of proteins present in a common cellular environment. To predict how two distinct networks of actin filaments control this balance, the simultaneous assembly of actin-related protein 2/3 (Arp2/3)-branched networks and formin-linear networks of actin filaments around polystyrene microbeads was investigated with a range of actin accessory proteins (profilin, capping protein, actin-depolymerizing factor [ADF]/cofilin, and tropomyosin). Accessory proteins generally affected actin assembly rates for the distinct networks differently. These effects at the scale of individual actin networks were surprisingly not always correlated with corresponding loss-of-function phenotypes in cells. However, our observations agreed with a global interpretation, which compared relative actin assembly rates of individual actin networks. This work supports a general model in which the size of distinct actin networks is determined by their relative capacity to assemble in a common and competing environment. A biomimetic assay using polystyrene beads compares the rates of actin assembly on linear and branched networks, revealing how the size of rival actin networks in cells is regulated by their relative capacity to assemble in a common environment.
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44
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Castaneda N, Lee M, Rivera-Jacquez HJ, Marracino RR, Merlino TR, Kang H. Actin Filament Mechanics and Structure in Crowded Environments. J Phys Chem B 2019; 123:2770-2779. [PMID: 30817154 DOI: 10.1021/acs.jpcb.8b12320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cellular environment is crowded with high concentrations of macromolecules that significantly reduce accessible volume for biomolecular interactions. Reductions in cellular volume can generate depletion forces that affect protein assembly and stability. The mechanical and structural properties of actin filaments play critical roles in various cellular functions, including structural support, cell movement, division, and intracellular transport. Although the effects of molecular crowding on actin polymerization have been shown, how crowded environments affect filament mechanics and structure is unknown. In this study, we investigate the effects of solution crowding on the modulations of actin filament bending stiffness and conformations both in vitro and in silico. Direct visualization of thermally fluctuating filaments in the presence of crowding agents is achieved by fluorescence microscopy imaging. Biophysical analysis indicates that molecular crowding enhances filament's effective bending stiffness and reduces average filament lengths. Utilizing the all-atom molecular dynamics simulations, we demonstrate that molecular crowding alters filament conformations and intersubunit contacts that are directly coupled to the mechanical properties of filaments. Taken together, our study suggests that the interplay between excluded volume effects and nonspecific interactions raised from molecular crowding may modulate actin filament mechanics and structure.
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Affiliation(s)
- Nicholas Castaneda
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States.,Burnett School of Biomedical Sciences, College of Medicine , University of Central Florida , Orlando , Florida 32827 , United States
| | - Myeongsang Lee
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States
| | - Hector J Rivera-Jacquez
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States
| | - Ryan R Marracino
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States.,Burnett School of Biomedical Sciences, College of Medicine , University of Central Florida , Orlando , Florida 32827 , United States
| | - Theresa R Merlino
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States
| | - Hyeran Kang
- NanoScience Technology Center , University of Central Florida , Orlando , Florida 32826 , United States
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45
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Manhart A, Icheva TA, Guerin C, Klar T, Boujemaa-Paterski R, Thery M, Blanchoin L, Mogilner A. Quantitative regulation of the dynamic steady state of actin networks. eLife 2019; 8:42413. [PMID: 30869077 PMCID: PMC6417862 DOI: 10.7554/elife.42413] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 02/26/2019] [Indexed: 12/30/2022] Open
Abstract
Principles of regulation of actin network dimensions are fundamentally important for cell functions, yet remain unclear. Using both in vitro and in silico approaches, we studied the effect of key parameters, such as actin density, ADF/Cofilin concentration and network width on the network length. In the presence of ADF/Cofilin, networks reached equilibrium and became treadmilling. At the trailing edge, the network disintegrated into large fragments. A mathematical model predicts the network length as a function of width, actin and ADF/Cofilin concentrations. Local depletion of ADF/Cofilin by binding to actin is significant, leading to wider networks growing longer. A single rate of breaking network nodes, proportional to ADF/Cofilin density and inversely proportional to the square of the actin density, can account for the disassembly dynamics. Selective disassembly of heterogeneous networks by ADF/Cofilin controls steering during motility. Our results establish general principles on how the dynamic steady state of actin network emerges from biochemical and structural feedbacks.
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Affiliation(s)
- Angelika Manhart
- Courant Institute of Mathematical Sciences, New York University, New York, United States.,Department of Biology, New York University, New York, United States
| | - Téa Aleksandra Icheva
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Christophe Guerin
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Tobbias Klar
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Rajaa Boujemaa-Paterski
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Manuel Thery
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France.,CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS1160, INSERM/AP-HP/Université Paris Diderot, Paris, France
| | - Laurent Blanchoin
- CytomorphoLab, Biosciences & Biotechnology Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France.,CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hematologie, UMRS1160, INSERM/AP-HP/Université Paris Diderot, Paris, France
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, United States.,Department of Biology, New York University, New York, United States
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46
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Torsional stress generated by ADF/cofilin on cross-linked actin filaments boosts their severing. Proc Natl Acad Sci U S A 2019; 116:2595-2602. [PMID: 30692249 PMCID: PMC6377502 DOI: 10.1073/pnas.1812053116] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Actin filaments assemble into ordered networks able to exert forces and shape cells. In response, filaments are exposed to mechanical stress which can potentially modulate their interactions with regulatory proteins. We developed in vitro tools to manipulate single filaments and study the impact of mechanics on the activity of actin depolymerizing factor (ADF)/cofilin, the central player in actin disassembly. While tension has almost no effect, curvature enhances severing by ADF/cofilin. We also discovered a mechanism that boosts the severing of anchored filaments: When binding to these filaments, ADF/cofilin locally increases their natural helicity, generating a torque that accelerates filament fragmentation up to 100-fold. As a consequence, interconnected filament networks are severed far more efficiently than independent filaments. Proteins of the actin depolymerizing factor (ADF)/cofilin family are the central regulators of actin filament disassembly. A key function of ADF/cofilin is to sever actin filaments. However, how it does so in a physiological context, where filaments are interconnected and under mechanical stress, remains unclear. Here, we monitor and quantify the action of ADF/cofilin in different mechanical situations by using single-molecule, single-filament, and filament network techniques, coupled to microfluidics. We find that local curvature favors severing, while tension surprisingly has no effect on cofilin binding and weakly enhances severing. Remarkably, we observe that filament segments that are held between two anchoring points, thereby constraining their twist, experience a mechanical torque upon cofilin binding. We find that this ADF/cofilin-induced torque does not hinder ADF/cofilin binding, but dramatically enhances severing. A simple model, which faithfully recapitulates our experimental observations, indicates that the ADF/cofilin-induced torque increases the severing rate constant 100-fold. A consequence of this mechanism, which we verify experimentally, is that cross-linked filament networks are severed by cofilin far more efficiently than nonconnected filaments. We propose that this mechanochemical mechanism is critical to boost ADF/cofilin’s ability to sever highly connected filament networks in cells.
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47
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Jansen S, Goode BL. Tropomyosin isoforms differentially tune actin filament length and disassembly. Mol Biol Cell 2019; 30:671-679. [PMID: 30650006 PMCID: PMC6589703 DOI: 10.1091/mbc.e18-12-0815] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cellular actin networks exhibit diverse filamentous architectures and turnover dynamics, but how these differences are specified remains poorly understood. Here, we used multicolor total internal reflection fluorescence microscopy to ask how decoration of actin filaments by five biologically prominent Tropomyosin (TPM) isoforms influences disassembly induced by Cofilin alone, or by the collaborative effects of Cofilin, Coronin, and AIP1 (CCA). TPM decoration restricted Cofilin binding to pointed ends, while not interfering with Coronin binding to filament sides. Different isoforms of TPM provided variable levels of protection against disassembly, with the strongest protection by Tpm3.1 and the weakest by Tpm1.6. In biomimetic assays in which filaments were simultaneously assembled by formins and disassembled by CCA, these TPM isoform-specific effects persisted, giving rise to filaments with different lengths and treadmilling behavior. Together, our data reveal that TPM isoforms have quantitatively distinct abilities to tune actin filament length and turnover.
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Affiliation(s)
- Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, MO 63110
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
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48
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Wioland H, Jegou A, Romet-Lemonne G. Quantitative Variations with pH of Actin Depolymerizing Factor/Cofilin's Multiple Actions on Actin Filaments. Biochemistry 2018; 58:40-47. [PMID: 30499293 PMCID: PMC6358128 DOI: 10.1021/acs.biochem.8b01001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
Actin
depolymerizing factor (ADF)/cofilin is the main protein family
promoting the disassembly of actin filaments, which is essential for
numerous cellular functions. ADF/cofilin proteins disassemble actin
filaments through different reactions, as they bind to their sides,
sever them, and promote the depolymerization of the resulting ADF/cofilin-saturated
filaments. Moreover, the efficiency of ADF/cofilin is known to be
very sensitive to pH. ADF/cofilin thus illustrates two challenges
in actin biochemistry: separating the different regulatory actions
of a single protein and characterizing them as a function of specific
biochemical conditions. Here, we investigate the different reactions
of ADF/cofilin on actin filaments, at four different pH values ranging
from 6.6 to 7.8, using single-filament microfluidics techniques. We
show that decreasing the pH decreases the effective filament severing
rate by increasing the rate at which filaments become saturated by
ADF/cofilin, thereby reducing the number of ADF/cofilin domain boundaries,
where severing can occur. The severing rate per domain boundary, however,
remains unchanged at different pH values. The ADF/cofilin-decorated
filaments (“cofilactin” filaments) depolymerize from
both ends. We show here that, at physiological pH (7.0–7.4),
the pointed end depolymerization of cofilactin filaments is barely
faster than that of bare filaments. In contrast, cofilactin barbed
ends undergo an “unstoppable” depolymerization (depolymerizing
for minutes despite the presence of free actin monomers and capping
protein in solution), throughout our pH range. We thus show that,
at physiological pH, the main contribution of ADF/cofilin to filament
depolymerization is at the barbed end.
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Affiliation(s)
- Hugo Wioland
- Institut Jacques Monod, CNRS, Université Paris-Diderot , 75013 Paris , France
| | - Antoine Jegou
- Institut Jacques Monod, CNRS, Université Paris-Diderot , 75013 Paris , France
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49
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Li X, Sun M, Men S, Shi Y, Ma L, An Y, Gao Y, Jin H, Liu W, Du Z. The Inflammatory Transcription Factor C/EBPβ Plays a Critical Role in Cardiac Fibroblast Differentiation and a Rat Model of Cardiac Fibrosis Induced by Autoimmune Myocarditis. Int Heart J 2018; 59:1389-1397. [DOI: 10.1536/ihj.17-446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Xiu Li
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Menghua Sun
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Suzhen Men
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Yanan Shi
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Lijuan Ma
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Yongqiang An
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Yaqing Gao
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Hui Jin
- Department of Cardiology, The Second People's Hospital of Guangdong Province
| | - Wei Liu
- Department of Cardiology, the Fourth Affiliated Hospital, Harbin Medical University
| | - Zuoyi Du
- Department of Cardiology, The Second People's Hospital of Guangdong Province
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50
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Hayakawa K, Sekiguchi C, Sokabe M, Ono S, Tatsumi H. Real-Time Single-Molecule Kinetic Analyses of AIP1-Enhanced Actin Filament Severing in the Presence of Cofilin. J Mol Biol 2018; 431:308-322. [PMID: 30439520 DOI: 10.1016/j.jmb.2018.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/17/2022]
Abstract
Rearrangement of actin filaments by polymerization, depolymerization, and severing is important for cell locomotion, membrane trafficking, and many other cellular functions. Cofilin and actin-interacting protein 1 (AIP1; also known as WDR1) are evolutionally conserved proteins that cooperatively sever actin filaments. However, little is known about the biophysical basis of the actin filament severing by these proteins. Here, we performed single-molecule kinetic analyses of fluorescently labeled AIP1 during the severing process of cofilin-decorated actin filaments. Results demonstrated that binding of a single AIP molecule was sufficient to enhance filament severing. After AIP1 binding to a filament, severing occurred with a delay of 0.7 s. Kinetics of binding and dissociation of a single AIP1 molecule to/from actin filaments followed a second-order and a first-order kinetics scheme, respectively. AIP1 binding and severing were detected preferentially at the boundary between the cofilin-decorated and bare regions on actin filaments. Based on the kinetic parameters explored in this study, we propose a possible mechanism behind the enhanced severing by AIP1.
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Affiliation(s)
- Kimihide Hayakawa
- Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya 466-8550, Japan
| | - Carina Sekiguchi
- Department of Physiology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya 466-8550, Japan
| | - Masahiro Sokabe
- Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, 65 Tsurumai, Nagoya 466-8550, Japan
| | - Shoichiro Ono
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hitoshi Tatsumi
- Department of Applied Bioscience, Kanazawa Institute of Technology (KIT), Ishikawa 924-0838, Japan.
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