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Han X, Hu Z, Surya W, Ma Q, Zhou F, Nordenskiöld L, Torres J, Lu L, Miao Y. The intrinsically disordered region of coronins fine-tunes oligomerization and actin polymerization. Cell Rep 2023; 42:112594. [PMID: 37269287 DOI: 10.1016/j.celrep.2023.112594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 04/21/2023] [Accepted: 05/16/2023] [Indexed: 06/05/2023] Open
Abstract
Coronins play critical roles in actin network formation. The diverse functions of coronins are regulated by the structured N-terminal β propeller and the C-terminal coiled coil (CC). However, less is known about a middle "unique region" (UR), which is an intrinsically disordered region (IDR). The UR/IDR is an evolutionarily conserved signature in the coronin family. By integrating biochemical and cell biology experiments, coarse-grained simulations, and protein engineering, we find that the IDR optimizes the biochemical activities of coronins in vivo and in vitro. The budding yeast coronin IDR plays essential roles in regulating Crn1 activity by fine-tuning CC oligomerization and maintaining Crn1 as a tetramer. The IDR-guided optimization of Crn1 oligomerization is critical for F-actin cross-linking and regulation of Arp2/3-mediated actin polymerization. The final oligomerization status and homogeneity of Crn1 are contributed by three examined factors: helix packing, the energy landscape of the CC, and the length and molecular grammar of the IDR.
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Affiliation(s)
- Xiao Han
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Zixin Hu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Wahyu Surya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Qianqian Ma
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Feng Zhou
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Jaume Torres
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; Institute for Digital Molecular Analytics and Science, Nanyang Technological University, Singapore 636921, Singapore.
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2
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Kim W, Jeon TJ. Dynamic subcellular localization of DydA in Dictyostelium cells. Biochem Biophys Res Commun 2023; 663:186-191. [PMID: 37121129 DOI: 10.1016/j.bbrc.2023.04.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/04/2023] [Accepted: 04/24/2023] [Indexed: 05/02/2023]
Abstract
DydA plays an important role in chemotaxis, development, and cell growth as an adaptor protein that connects Ras signaling and cytoskeletal rearrangement. DydA is a downstream effector of RasG and is involved in controlling cell polarity and pseudopodia formation during chemoattractant-directed cell migration. To understand the mechanism by which DydA functions on the cell migration, we investigated the dynamic subcellular localization of DydA in response to chemoattractant stimulation and found that DydA rapidly and transiently translocated to the cell cortex through the RA domain and the PRM region in DydA in response to chemoattractant stimulation. The PRM region appears to play a primary role in the translocation of DydA to the cell cortex and in its localization to the actin foci at the bottom of cells. Colocalization experiments of GFP-PRM with RFP-coronin indicated that GFP-PRM preceded GFP-coronin by 2-3 s in response to chemoattractant stimulation. These results suggest that the PRM region plays an indispensable role in relaying upstream regulators, such as RasG, to downstream effectors by mediating the localization of DydA to the cell cortex upon chemoattractant stimulation.
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Affiliation(s)
- Wonbum Kim
- Department of Life Science, BK21 FOUR Educational Research Group for Age-Associated Disorder Control Technology, Chosun University, Gwangju, 61452, Republic of Korea
| | - Taeck Joong Jeon
- Department of Life Science, BK21 FOUR Educational Research Group for Age-Associated Disorder Control Technology, Chosun University, Gwangju, 61452, Republic of Korea.
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3
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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: 72] [Impact Index Per Article: 36.0] [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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4
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King ZT, Butler MT, Hockenberry MA, Subramanian BC, Siesser PF, Graham DM, Legant WR, Bear JE. Coro1B and Coro1C regulate lamellipodia dynamics and cell motility by tuning branched actin turnover. J Cell Biol 2022; 221:e202111126. [PMID: 35657370 PMCID: PMC9170525 DOI: 10.1083/jcb.202111126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/01/2022] [Accepted: 05/18/2022] [Indexed: 02/03/2023] Open
Abstract
Actin filament dynamics must be precisely controlled in cells to execute behaviors such as vesicular trafficking, cytokinesis, and migration. Coronins are conserved actin-binding proteins that regulate several actin-dependent subcellular processes. Here, we describe a new conditional knockout cell line for two ubiquitous coronins, Coro1B and Coro1C. These coronins, which strongly co-localize with Arp2/3-branched actin, require Arp2/3 activity for proper subcellular localization. Coronin null cells have altered lamellipodial protrusion dynamics due to increased branched actin density and reduced actin turnover within lamellipodia, leading to defective haptotaxis. Surprisingly, excessive cofilin accumulates in coronin null lamellipodia, a result that is inconsistent with the current models of coronin-cofilin functional interaction. However, consistent with coronins playing a pro-cofilin role, coronin null cells have increased F-actin levels. Lastly, we demonstrate that the loss of coronins increases accompanied by an increase in cellular contractility. Together, our observations reveal that coronins are critical for proper turnover of branched actin networks and that decreased actin turnover leads to increased cellular contractility.
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Affiliation(s)
- Zayna T. King
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Mitchell T. Butler
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Max A. Hockenberry
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Bhagawat C. Subramanian
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Priscila F. Siesser
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - David M. Graham
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - Wesley R. Legant
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
- Department of Pharmacology, University of North Carolina-Chapel Hill School of Medicine, Chapel Hill, NC
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5
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Abstract
Eukaryotic cells contain branched actin networks that are essential for endocytosis, motility, and other key cellular processes. These networks, which are formed by filamentous actin and the Arp2/3 complex, must subsequently be debranched to allow network remodeling and to recycle the Arp2/3 complex. Debranching appears to be catalyzed by two different members of the actin depolymerizing factor homology protein family: cofilin and glial maturation factor (GMF). However, their mechanisms of debranching are only partially understood. Here, we used single-molecule fluorescence imaging of Arp2/3 complex and actin filaments under physiological ionic conditions to observe debranching by GMF and cofilin. We demonstrate that cofilin, like GMF, is an authentic debrancher independent of its filament-severing activity and that the debranching activities of the two proteins are additive. While GMF binds directly to the Arp2/3 complex, cofilin selectively accumulates on branch-junction daughter filaments in tropomyosin-decorated networks just prior to debranching events. Quantitative comparison of debranching rates with the known kinetics of cofilin-actin binding suggests that cofilin occupancy of a particular single actin site at the branch junction is sufficient to trigger debranching. In rare cases in which the order of departure could be resolved during GMF- or cofilin-induced debranching, the Arp2/3 complex left the branch junction bound to the pointed end of the daughter filament, suggesting that both GMF and cofilin can work by destabilizing the mother filament-Arp2/3 complex interface. Taken together, these observations suggest that GMF and cofilin promote debranching by distinct yet complementary mechanisms.
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6
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Fokin AI, Chuprov-Netochin RN, Malyshev AS, Romero S, Semenova MN, Konyushkin LD, Leonov SV, Semenov VV, Gautreau AM. Synthesis, Screening and Characterization of Novel Potent Arp2/3 Inhibitory Compounds Analogous to CK-666. Front Pharmacol 2022; 13:896994. [PMID: 35707404 PMCID: PMC9189929 DOI: 10.3389/fphar.2022.896994] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/08/2022] [Indexed: 12/02/2022] Open
Abstract
Branched actin networks polymerized by the Actin-related protein 2 and 3 (Arp2/3) complex play key roles in force generation and membrane remodeling. These networks are particularly important for cell migration, where they drive membrane protrusions of lamellipodia. Several Arp2/3 inhibitory compounds have been identified. Among them, the most widely used is CK-666 (2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]-benzamide), whose mode of action is to prevent Arp2/3 from reaching its active conformation. Here 74 compounds structurally related to CK-666 were screened using a variety of assays. The primary screen involved EdU (5-ethynyl-2′-deoxyuridine) incorporation in untransformed MCF10A cells. The resulting nine positive hits were all blocking lamellipodial protrusions and cell migration in B16-F1 melanoma cells in secondary screens, showing that cell cycle progression can be a useful read-out of Arp2/3 activity. Selected compounds were also characterized on sea urchin embryos, where Arp2/3 inhibition yields specific phenotypes such as the lack of triradiate spicules and inhibition of archenteron elongation. Several compounds were filtered out due to their toxicity in cell cultures or on sea urchin development. Two CK-666 analogs, 59 (N-{2-[5-(Benzyloxy)-2-methyl-1H-indol-3-yl] ethyl}-3-bromobenzamide) and 69 (2,4-Dichloro-N-[2-(7-chloro-2-methyl-1H-indol-3-yl) ethyl]-5-[(dimethylamino) sulfonyl] benzamide), were active in all assays and significantly more efficient in vivo than CK-666. These best hits with increased in vivo potency were, however, slightly less efficient in vitro than CK-666 in the classical pyrene-actin assay. Induced-fit docking of selected compounds and their possible metabolites revealed interaction with Arp2/3 that suppresses Arp2/3 activation. The data obtained in our screening validated the applicability of original assays for Arp2/3 activity. Several previously unexplored CK-666 structural analogs were found to suppress Arp2/3 activation, and two of them were identified as Arp2/3 inhibitors with improved in vivo efficiency.
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Affiliation(s)
- Artem I. Fokin
- CNRS UMR7654, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
- *Correspondence: Artem I. Fokin, ; Alexis M. Gautreau,
| | - Roman N. Chuprov-Netochin
- Department of Molecular and Bio Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Alexander S. Malyshev
- Lomonosov Moscow State University, Faculty of Medicine, Moscow, Russia
- Dukhov Research Institute of Automatics (VNIIA), Moscow, Russia
| | - Stéphane Romero
- CNRS UMR7654, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | | | | | - Sergey V. Leonov
- Department of Molecular and Bio Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | | | - Alexis M. Gautreau
- CNRS UMR7654, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
- Center of Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
- *Correspondence: Artem I. Fokin, ; Alexis M. Gautreau,
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7
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Vakhrusheva A, Murashko A, Trifonova E, Efremov Y, Timashev P, Sokolova O. Role of Actin-binding Proteins in the Regulation of Cellular Mechanics. Eur J Cell Biol 2022; 101:151241. [DOI: 10.1016/j.ejcb.2022.151241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/18/2022] [Accepted: 05/19/2022] [Indexed: 12/25/2022] Open
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8
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Sun J, Zhong X, Fu X, Miller H, Lee P, Yu B, Liu C. The Actin Regulators Involved in the Function and Related Diseases of Lymphocytes. Front Immunol 2022; 13:799309. [PMID: 35371070 PMCID: PMC8965893 DOI: 10.3389/fimmu.2022.799309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/01/2022] [Indexed: 11/21/2022] Open
Abstract
Actin is an important cytoskeletal protein involved in signal transduction, cell structure and motility. Actin regulators include actin-monomer-binding proteins, Wiskott-Aldrich syndrome (WAS) family of proteins, nucleation proteins, actin filament polymerases and severing proteins. This group of proteins regulate the dynamic changes in actin assembly/disassembly, thus playing an important role in cell motility, intracellular transport, cell division and other basic cellular activities. Lymphocytes are important components of the human immune system, consisting of T-lymphocytes (T cells), B-lymphocytes (B cells) and natural killer cells (NK cells). Lymphocytes are indispensable for both innate and adaptive immunity and cannot function normally without various actin regulators. In this review, we first briefly introduce the structure and fundamental functions of a variety of well-known and newly discovered actin regulators, then we highlight the role of actin regulators in T cell, B cell and NK cell, and finally provide a landscape of various diseases associated with them. This review provides new directions in exploring actin regulators and promotes more precise and effective treatments for related diseases.
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Affiliation(s)
- Jianxuan Sun
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department and Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingyu Zhong
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoyu Fu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Heather Miller
- Cytek Biosciences, R&D Clinical Reagents, Fremont, CA, United States
| | - Pamela Lee
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Bing Yu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chaohong Liu
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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9
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Fujimoto K, Nakano K, Kuwayama H, Yumura S. Deletion of gmfA induces keratocyte-like migration in Dictyostelium. FEBS Open Bio 2021; 12:306-319. [PMID: 34855306 PMCID: PMC8727941 DOI: 10.1002/2211-5463.13339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/15/2021] [Accepted: 11/30/2021] [Indexed: 11/06/2022] Open
Abstract
Glia maturation factor (GMF) has been established as an inactivating factor of the actin‐related protein 2/3 (Arp2/3) complex, which regulates actin assembly. Regulation of actin assembly and reorganization is crucial for various cellular events, such as cell migration, cell division, and development. Here, to examine the roles of ADF‐H domain‐containing protein (also known as glia maturation factor; GmfA), the product of a single GMF homologous gene in Dictyostelium, gmfA‐null cells were generated. They had moderate defects in cell growth and cytokinesis. Interestingly, they showed a keratocyte‐like fan shape with a broader pseudopod, where Arp3 accumulated at higher levels than in wild‐type cells. They migrated with higher persistence, but their velocities were comparable to those of wild‐type cells. The polar pseudopods during cell division were also broader than those in wild‐type cells. However, GmfA did not localize at the pseudopods in migrating cells or the polar pseudopods in dividing cells. Adhesions of mutant cells to the substratum were much stronger than that of wild‐type cells. Although the mutant cells showed chemotaxis comparable to that of wild‐type cells, they formed disconnected streams during the aggregation stage; however, they finally formed normal fruiting bodies. These results suggest that GmfA plays a crucial role in cell migration.
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Affiliation(s)
- Koushiro Fujimoto
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Japan
| | - Kentaro Nakano
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan
| | - Hidekazu Kuwayama
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan
| | - Shigehiko Yumura
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Japan
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10
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Law AL, Jalal S, Pallett T, Mosis F, Guni A, Brayford S, Yolland L, Marcotti S, Levitt JA, Poland SP, Rowe-Sampson M, Jandke A, Köchl R, Pula G, Ameer-Beg SM, Stramer BM, Krause M. Nance-Horan Syndrome-like 1 protein negatively regulates Scar/WAVE-Arp2/3 activity and inhibits lamellipodia stability and cell migration. Nat Commun 2021; 12:5687. [PMID: 34584076 PMCID: PMC8478917 DOI: 10.1038/s41467-021-25916-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 09/03/2021] [Indexed: 12/02/2022] Open
Abstract
Cell migration is important for development and its aberrant regulation contributes to many diseases. The Scar/WAVE complex is essential for Arp2/3 mediated lamellipodia formation during mesenchymal cell migration and several coinciding signals activate it. However, so far, no direct negative regulators are known. Here we identify Nance-Horan Syndrome-like 1 protein (NHSL1) as a direct binding partner of the Scar/WAVE complex, which co-localise at protruding lamellipodia. This interaction is mediated by the Abi SH3 domain and two binding sites in NHSL1. Furthermore, active Rac binds to NHSL1 at two regions that mediate leading edge targeting of NHSL1. Surprisingly, NHSL1 inhibits cell migration through its interaction with the Scar/WAVE complex. Mechanistically, NHSL1 may reduce cell migration efficiency by impeding Arp2/3 activity, as measured in cells using a Arp2/3 FRET-FLIM biosensor, resulting in reduced F-actin density of lamellipodia, and consequently impairing the stability of lamellipodia protrusions.
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Affiliation(s)
- Ah-Lai Law
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- School of Life Sciences, University of Bedfordshire, Luton, LU1 3JU, UK
| | - Shamsinar Jalal
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Tommy Pallett
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Fuad Mosis
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Ahmad Guni
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Simon Brayford
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Lawrence Yolland
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Stefania Marcotti
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - James A Levitt
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Simon P Poland
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Maia Rowe-Sampson
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Anett Jandke
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Immunosurveillance Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Robert Köchl
- School of Immunology and Microbial Sciences, King's College London, Guy's Campus, London, SE1 1UL, UK
| | - Giordano Pula
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg (UKE), Martinistrasse 52, O26, 20246, Hamburg, Germany
| | - Simon M Ameer-Beg
- Ameer-Beg Group, Richard Dimbleby Cancer Research Laboratories, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Brian Marc Stramer
- Stramer Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Matthias Krause
- Krause Group, Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.
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11
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Actin filament debranching regulates cell polarity during cell migration and asymmetric cell division. Proc Natl Acad Sci U S A 2021; 118:2100805118. [PMID: 34507987 DOI: 10.1073/pnas.2100805118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2021] [Indexed: 01/10/2023] Open
Abstract
The formation of the branched actin networks is essential for cell polarity, but it remains unclear how the debranching activity of actin filaments contributes to this process. Here, we showed that an evolutionarily conserved coronin family protein, the Caenorhabditis elegans POD-1, debranched the Arp2/3-nucleated actin filaments in vitro. By fluorescence live imaging analysis of the endogenous POD-1 protein, we found that POD-1 colocalized with Arp2/3 at the leading edge of the migrating C. elegans neuroblasts. Conditional mutations of POD-1 in neuroblasts caused aberrant actin assembly, disrupted cell polarity, and impaired cell migration. In C. elegans one-cell-stage embryos, POD-1 and Arp2/3, moved together during cell polarity establishment, and inhibition of POD-1 blocked Arp2/3 motility and affected the polarized cortical flow, leading to symmetric segregation of cell fate determinants. Together, these results indicate that F-actin debranching organizes actin network and cell polarity in migrating neuroblasts and asymmetrically dividing embryos.
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12
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Chin S, Kwon T, Khan BR, Sparks JA, Mallery EL, Szymanski DB, Blancaflor EB. Spatial and temporal localization of SPIRRIG and WAVE/SCAR reveal roles for these proteins in actin-mediated root hair development. THE PLANT CELL 2021; 33:2131-2148. [PMID: 33881536 PMCID: PMC8364238 DOI: 10.1093/plcell/koab115] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 05/31/2023]
Abstract
Root hairs are single-cell protrusions that enable roots to optimize nutrient and water acquisition. These structures attain their tubular shapes by confining growth to the cell apex, a process called tip growth. The actin cytoskeleton and endomembrane systems are essential for tip growth; however, little is known about how these cellular components coordinate their activities during this process. Here, we show that SPIRRIG (SPI), a beige and Chediak Higashi domain-containing protein involved in membrane trafficking, and BRK1 and SCAR2, subunits of the WAVE/SCAR (W/SC) actin nucleating promoting complex, display polarized localizations in Arabidopsis thaliana root hairs during distinct developmental stages. SPI accumulates at the root hair apex via post-Golgi compartments and positively regulates tip growth by maintaining tip-focused vesicle secretion and filamentous-actin integrity. BRK1 and SCAR2 on the other hand, mark the root hair initiation domain to specify the position of root hair emergence. Consistent with the localization data, tip growth was reduced in spi and the position of root hair emergence was disrupted in brk1 and scar1234. BRK1 depletion coincided with SPI accumulation as root hairs transitioned from initiation to tip growth. Taken together, our work uncovers a role for SPI in facilitating actin-dependent root hair development in Arabidopsis through pathways that might intersect with W/SC.
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Affiliation(s)
- Sabrina Chin
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
| | - Taegun Kwon
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
| | - Bibi Rafeiza Khan
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
| | - J. Alan Sparks
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
| | - Eileen L. Mallery
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Daniel B. Szymanski
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
| | - Elison B. Blancaflor
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
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The multiple roles of actin-binding proteins at invadopodia. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021. [PMID: 33962752 DOI: 10.1016/bs.ircmb.2021.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Invadopodia are actin-rich membrane protrusions that facilitate cancer cell dissemination by focusing on proteolytic activity and clearing paths for migration through physical barriers, such as basement membranes, dense extracellular matrices, and endothelial cell junctions. Invadopodium formation and activity require spatially and temporally regulated changes in actin filament organization and dynamics. About three decades of research have led to a remarkable understanding of how these changes are orchestrated by sequential recruitment and coordinated activity of different sets of actin-binding proteins. In this chapter, we provide an update on the roles of the actin cytoskeleton during the main stages of invadopodium development with a particular focus on actin polymerization machineries and production of pushing forces driving extracellular matrix remodeling.
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Orbach R, Su X. Surfing on Membrane Waves: Microvilli, Curved Membranes, and Immune Signaling. Front Immunol 2020; 11:2187. [PMID: 33013920 PMCID: PMC7516127 DOI: 10.3389/fimmu.2020.02187] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/11/2020] [Indexed: 01/22/2023] Open
Abstract
Microvilli are finger-like membrane protrusions, supported by the actin cytoskeleton, and found on almost all cell types. A growing body of evidence suggests that the dynamic lymphocyte microvilli, with their highly curved membranes, play an important role in signal transduction leading to immune responses. Nevertheless, challenges in modulating local membrane curvature and monitoring the high dynamicity of microvilli hampered the investigation of the curvature-generation mechanism and its functional consequences in signaling. These technical barriers have been partially overcome by recent advancements in adapted super-resolution microscopy. Here, we review the up-to-date progress in understanding the mechanisms and functional consequences of microvillus formation in T cell signaling. We discuss how the deformation of local membranes could potentially affect the organization of signaling proteins and their biochemical activities. We propose that curved membranes, together with the underlying cytoskeleton, shape microvilli into a unique compartment that sense and process signals leading to lymphocyte activation.
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Affiliation(s)
- Ron Orbach
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, United States
| | - Xiaolei Su
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, United States
- Yale Cancer Center, Yale University, New Haven, CT, United States
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15
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Shaaban M, Chowdhury S, Nolen BJ. Cryo-EM reveals the transition of Arp2/3 complex from inactive to nucleation-competent state. Nat Struct Mol Biol 2020; 27:1009-1016. [PMID: 32839613 DOI: 10.1038/s41594-020-0481-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/10/2020] [Indexed: 12/29/2022]
Abstract
Arp2/3 complex, a crucial actin filament nucleator, undergoes structural rearrangements during activation by nucleation-promoting factors (NPFs). However, the conformational pathway leading to the nucleation-competent state is unclear due to lack of high-resolution structures of the activated state. Here we report a ~3.9 Å resolution cryo-EM structure of activated Schizosaccharomyces pombe Arp2/3 complex bound to the S. pombe NPF Dip1 and attached to the end of the nucleated actin filament. The structure reveals global and local conformational changes that allow the two actin-related proteins in Arp2/3 complex to mimic a filamentous actin dimer and template nucleation. Activation occurs through a clamp-twisting mechanism, in which Dip1 forces two core subunits in Arp2/3 complex to pivot around one another, shifting half of the complex into a new activated position. By showing how Dip1 stimulates activation, the structure reveals how NPFs can activate Arp2/3 complex in diverse cellular processes.
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Affiliation(s)
- Mohammed Shaaban
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Saikat Chowdhury
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA.
| | - Brad J Nolen
- Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA.
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16
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von Loeffelholz O, Purkiss A, Cao L, Kjaer S, Kogata N, Romet-Lemonne G, Way M, Moores CA. Cryo-EM of human Arp2/3 complexes provides structural insights into actin nucleation modulation by ARPC5 isoforms. Biol Open 2020; 9:bio054304. [PMID: 32661131 PMCID: PMC7406314 DOI: 10.1242/bio.054304] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 06/30/2020] [Indexed: 12/30/2022] Open
Abstract
The Arp2/3 complex regulates many cellular processes by stimulating formation of branched actin filament networks. Because three of its seven subunits exist as two different isoforms, mammals produce a family of Arp2/3 complexes with different properties that may be suited to different physiological contexts. To shed light on how isoform diversification affects Arp2/3 function, we determined a 4.2 Å resolution cryo-EM structure of the most active human Arp2/3 complex containing ARPC1B and ARPC5L, and compared it with the structure of the least active ARPC1A-ARPC5-containing complex. The architecture of each isoform-specific Arp2/3 complex is the same. Strikingly, however, the N-terminal half of ARPC5L is partially disordered compared to ARPC5, suggesting that this region of ARPC5/ARPC5L is an important determinant of complex activity. Confirming this idea, the nucleation activity of Arp2/3 complexes containing hybrid ARPC5/ARPC5L subunits is higher when the ARPC5L N-terminus is present, thereby providing insight into activity differences between the different Arp2/3 complexes.
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Affiliation(s)
- Ottilie von Loeffelholz
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
| | - Andrew Purkiss
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Luyan Cao
- Université de Paris, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Svend Kjaer
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Naoko Kogata
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Michael Way
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Department of Infectious Disease, Imperial College London, London W2 1PG, UK
| | - Carolyn A Moores
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK
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17
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Grikscheit K, Dolnik O, Takamatsu Y, Pereira AR, Becker S. Ebola Virus Nucleocapsid-Like Structures Utilize Arp2/3 Signaling for Intracellular Long-Distance Transport. Cells 2020; 9:cells9071728. [PMID: 32707734 PMCID: PMC7407605 DOI: 10.3390/cells9071728] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/12/2020] [Accepted: 07/16/2020] [Indexed: 11/16/2022] Open
Abstract
The intracellular transport of nucleocapsids of the highly pathogenic Marburg, as well as Ebola virus (MARV, EBOV), represents a critical step during the viral life cycle. Intriguingly, a population of these nucleocapsids is distributed over long distances in a directed and polar fashion. Recently, it has been demonstrated that the intracellular transport of filoviral nucleocapsids depends on actin polymerization. While it was shown that EBOV requires Arp2/3-dependent actin dynamics, the details of how the virus exploits host actin signaling during intracellular transport are largely unknown. Here, we apply a minimalistic transfection system to follow the nucleocapsid-like structures (NCLS) in living cells, which can be used to robustly quantify NCLS transport in live cell imaging experiments. Furthermore, in cells co-expressing LifeAct, a marker for actin dynamics, NCLS transport is accompanied by pulsative actin tails appearing on the rear end of NCLS. These actin tails can also be preserved in fixed cells, and can be visualized via high resolution imaging using STORM in transfected, as well as EBOV infected, cells. The application of inhibitory drugs and siRNA depletion against actin regulators indicated that EBOV NCLS utilize the canonical Arp2/3-Wave1-Rac1 pathway for long-distance transport in cells. These findings highlight the relevance of the regulation of actin polymerization during directed EBOV nucleocapsid transport in human cells.
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Affiliation(s)
- Katharina Grikscheit
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany; (K.G.); (O.D.); (Y.T.)
- German Center for Infection Research (DZIF), Partner Site: Giessen-Marburg-Langen, Hans-Meerwein-Str. 2, 35043 Marburg, Germany
| | - Olga Dolnik
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany; (K.G.); (O.D.); (Y.T.)
| | - Yuki Takamatsu
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany; (K.G.); (O.D.); (Y.T.)
- Department of Virology I, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | | | - Stephan Becker
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany; (K.G.); (O.D.); (Y.T.)
- German Center for Infection Research (DZIF), Partner Site: Giessen-Marburg-Langen, Hans-Meerwein-Str. 2, 35043 Marburg, Germany
- Correspondence:
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18
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Jeon P, Jeon TJ. WasC, a WASP family protein, is involved in cell adhesion and migration through regulation of F-actin polymerization in Dictyostelium. J Microbiol 2020; 58:696-702. [PMID: 32524343 DOI: 10.1007/s12275-020-0138-9] [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: 03/13/2020] [Revised: 04/29/2020] [Accepted: 05/18/2020] [Indexed: 11/24/2022]
Abstract
The actin cytoskeleton is involved in the regulation of cell morphology and migration. Wiskott-Aldrich Syndrome proteins (WASPs) play an important role in controlling actin polymerization by activating the Arp2/3 complex. The present study investigated the roles of WasC, one of the 3 WASPs in Dictyostelium, in cellular processes. Cells lacking WasC displayed strong cell adhesion and approximately 1.5-fold increase in F-actin levels as compared to the wild-type cells. Loss of wasC caused defects in phagocytosis and decreased the migration speed in chemoattractant-mediated cell migration but did not affect directionality. WasC was localized to the protruding region in migrating cells and, transiently and rapidly translocated to the cell cortex in response to chemoattractant stimulation, in an F-actin dependent manner. Our results suggest that WasC is involved in cell adhesion and migration by regulating F-actin polymerization at the leading edge of migrating cells, probably as a negative regulator. The increased strength of adhesion in wasC null cells is likely to decrease the migration speed but not the directionality.
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Affiliation(s)
- Pyeonghwa Jeon
- Department of Biology & BK21- Plus Research Team for Bioactive Control Technology, College of Natural Sciences, Chosun University, Gwangju, 61452, Republic of Korea
| | - Taeck Joong Jeon
- Department of Biology & BK21- Plus Research Team for Bioactive Control Technology, College of Natural Sciences, Chosun University, Gwangju, 61452, Republic of Korea.
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Zimmet A, Van Eeuwen T, Boczkowska M, Rebowski G, Murakami K, Dominguez R. Cryo-EM structure of NPF-bound human Arp2/3 complex and activation mechanism. SCIENCE ADVANCES 2020; 6:6/23/eaaz7651. [PMID: 32917641 PMCID: PMC7274804 DOI: 10.1126/sciadv.aaz7651] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 04/16/2020] [Indexed: 05/12/2023]
Abstract
Actin-related protein (Arp) 2/3 complex nucleates branched actin networks that drive cell motility. It consists of seven proteins, including two actin-related subunits (Arp2 and Arp3). Two nucleation-promoting factors (NPFs) bind Arp2/3 complex during activation, but the order, specific interactions, and contribution of each NPF to activation are unresolved. Here, we report the cryo-electron microscopy structure of recombinantly expressed human Arp2/3 complex with two WASP family NPFs bound and address the mechanism of activation. A cross-linking assay that captures the transition of the Arps into the activated filament-like conformation shows that actin binding to NPFs favors this transition. Actin-NPF binding to Arp2 precedes binding to Arp3 and is sufficient to promote the filament-like conformation but not activation. Structure-guided mutagenesis of the NPF-binding sites reveals their distinct roles in activation and shows that, contrary to budding yeast Arp2/3 complex, NPF-mediated delivery of actin at the barbed end of both Arps is required for activation of human Arp2/3 complex.
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Affiliation(s)
- Austin Zimmet
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Trevor Van Eeuwen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Malgorzata Boczkowska
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Grzegorz Rebowski
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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20
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Li T, Liu X, Xu B, Wu W, Zang Y, Li J, Wei L, Qian Y, Xu H, Xie M, Wang Q, Wang L. SKA1 regulates actin cytoskeleton remodelling via activating Cdc42 and influences the migration of pancreatic ductal adenocarcinoma cells. Cell Prolif 2020; 53:e12799. [PMID: 32232899 PMCID: PMC7162805 DOI: 10.1111/cpr.12799] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/08/2020] [Accepted: 03/04/2020] [Indexed: 12/29/2022] Open
Abstract
Objectives Spindle and kinetochore–associated protein 1(SKA1), originally identified as a protein essential for proper chromosome segregation, has been recently linked to multiple malignancies. This study aimed to explore the biological, clinical role and molecular mechanism of SKA1 in pancreatic carcinogenesis. Materials and Methods SKA1 expression was detected in 145 pancreatic ductal adenocarcinoma (PDAC) specimens by immunohistochemistry. Biological behaviour assays were used to determine the role of SKA1 in PDAC progression in vitro and in vivo. Using isobaric tags for relative and absolute quantitation (iTRAQ), SKA1’s downstream proteins were examined. Moreover, cytochalasin B and ZCL278 were used to explore the changes of SKA1‐induced signalling and cell morphology, with further confirmation by immunoblotting and immunofluorescence assays. Results Increased SKA1 expression was significantly correlated with tumour size and cellular differentiation degree in PDAC tissues. Furthermore, elevated levels of SKA1 reflected shorter overall survival (P = .019). As for biological behaviour, SKA1 acted as a tumour promotor in PDAC, overexpression of SKA1 facilitates cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, we demonstrated that SKA1 enhanced pancreatic cancer aggressiveness by inhibiting G2/M arrest and regulating actin cytoskeleton organization via activating Cdc42. Conclusions This study revealed novel roles for SKA1 as an important regulator of actin cytoskeleton organization and an oncogene in PDAC cells, which may provide insights into developing novel therapeutics.
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Affiliation(s)
- Tong Li
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Liu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Xu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Zang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juanjuan Li
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lumin Wei
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuting Qian
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui Xu
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingping Xie
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qi Wang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lifu Wang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Shi X, Duan F, Lin L, Xu Q, Xu T, Zhang R. WIP-1 and DBN-1 promote scission of endocytic vesicles by bridging actin and Dynamin-1 in the C. elegans intestine. J Cell Sci 2019; 132:jcs.228023. [PMID: 31118234 DOI: 10.1242/jcs.228023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/13/2019] [Indexed: 01/13/2023] Open
Abstract
There has been a consensus that actin plays an important role in scission of the clathrin-coated pits (CCPs) together with large GTPases of the dynamin family in metazoan cells. However, the recruitment, regulation and functional interdependence of actin and dynamin during this process remain inadequately understood. Here, based on small-scale screening and in vivo live-imaging techniques, we identified a novel set of molecules underlying CCP scission in the multicellular organism Caenorhabditis elegans We found that loss of Wiskott-Aldrich syndrome protein (WASP)-interacting protein (WIP-1) impaired CCP scission in a manner that is independent of the C. elegans homolog of WASP/N-WASP (WSP-1) and is mediated by direct binding to G-actin. Moreover, the cortactin-binding domain of WIP-1 serves as the binding interface for DBN-1 (also known in other organisms as Abp1), another actin-binding protein. We demonstrate that the interaction between DBN-1 and F-actin is essential for Dynamin-1 (DYN-1) recruitment at endocytic sites. In addition, the recycling regulator RME-1, a homolog of mammalian Eps15 homology (EH) domain-containing proteins, is increasingly recruited at the arrested endocytic intermediates induced by F-actin loss or DYN-1 inactivation, which further stabilizes the tubular endocytic intermediates. Our study provides new insights into the molecular network underlying F-actin participation in the scission of CCPs.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Xuemeng Shi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Fengyun Duan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Long Lin
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qifeng Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Tao Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China .,National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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22
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Naik J, Hau CM, ten Bloemendaal L, Mok KS, Hajji N, Wehman AM, Meisner S, Muncan V, Paauw NJ, de Vries HE, Nieuwland R, Paulusma CC, Bosma PJ. The P4-ATPase ATP9A is a novel determinant of exosome release. PLoS One 2019; 14:e0213069. [PMID: 30947313 PMCID: PMC6448858 DOI: 10.1371/journal.pone.0213069] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 02/14/2019] [Indexed: 01/05/2023] Open
Abstract
Extracellular vesicles (EVs) released by cells have a role in intercellular communication to regulate a wide range of biological processes. Two types of EVs can be recognized. Exosomes, which are released from multi-vesicular bodies upon fusion with the plasma membrane, and ectosomes, which directly bud from the plasma membrane. How cells regulate the quantity of EV release is largely unknown. One of the initiating events in vesicle biogenesis is the regulated transport of phospholipids from the exoplasmic to the cytosolic leaflet of biological membranes. This process is catalyzed by P4-ATPases. The role of these phospholipid transporters in intracellular vesicle transport has been established in lower eukaryotes and is slowly emerging in mammalian cells. In Caenorhabditis elegans (C. elegans), deficiency of the P4-ATPase member TAT-5 resulted in enhanced EV shedding, indicating a role in the regulation of EV release. In this study, we investigated whether the mammalian ortholog of TAT-5, ATP9A, has a similar function in mammalian cells. We show that knockdown of ATP9A expression in human hepatoma cells resulted in a significant increase in EV release that was independent of caspase-3 activation. Pharmacological blocking of exosome release in ATP9A knockdown cells did significantly reduce the total number of EVs. Our data support a role for ATP9A in the regulation of exosome release from human cells.
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Affiliation(s)
- Jyoti Naik
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
| | - Chi M. Hau
- Laboratory of Experimental Clinical Chemistry, Vesicle Observation Centre, Amsterdam University Medical Centers, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands
| | - Lysbeth ten Bloemendaal
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
| | - Kam S. Mok
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
| | - Najat Hajji
- Laboratory of Experimental Clinical Chemistry, Vesicle Observation Centre, Amsterdam University Medical Centers, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands
| | - Ann M. Wehman
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Sander Meisner
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
| | - Vanesa Muncan
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
| | - Nanne J. Paauw
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Centers, VU University Medical Center, Amsterdam, The Netherlands
| | - H. E. de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Centers, VU University Medical Center, Amsterdam, The Netherlands
| | - Rienk Nieuwland
- Laboratory of Experimental Clinical Chemistry, Vesicle Observation Centre, Amsterdam University Medical Centers, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands
| | - Coen C. Paulusma
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
- * E-mail: (PJB); (CEP)
| | - Piter J. Bosma
- Amsterdam University Medical Centers, university of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology and Metabolism, Amsterdam, The Netherlands
- * E-mail: (PJB); (CEP)
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Conformational changes in Arp2/3 complex induced by ATP, WASp-VCA, and actin filaments. Proc Natl Acad Sci U S A 2018; 115:E8642-E8651. [PMID: 30150414 DOI: 10.1073/pnas.1717594115] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We used fluorescence spectroscopy and EM to determine how binding of ATP, nucleation-promoting factors, actin monomers, and actin filaments changes the conformation of Arp2/3 complex during the process that nucleates an actin filament branch. We mutated subunits of Schizosaccharomyces pombe Arp2/3 complex for labeling with fluorescent dyes at either the C termini of Arp2 and Arp3 or ArpC1 and ArpC3. We measured Förster resonance energy transfer (FRET) efficiency (ETeff) between the dyes in the presence of the various ligands. We also computed class averages from electron micrographs of negatively stained specimens. ATP binding made small conformational changes of the nucleotide-binding cleft of the Arp2 subunit. WASp-VCA, WASp-CA, and WASp-actin-VCA changed the ETeff between the dyes on the Arp2 and Arp3 subunits much more than between dyes on ArpC1 and ArpC3. Ensemble FRET detected an additional structural change that brought ArpC1 and ArpC3 closer together when Arp2/3 complex bound actin filaments. VCA binding to Arp2/3 complex causes a conformational change that favors binding to the side of an actin filament, which allows further changes required to nucleate a daughter filament.
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Abp1 promotes Arp2/3 complex-dependent actin nucleation and stabilizes branch junctions by antagonizing GMF. Nat Commun 2018; 9:2895. [PMID: 30042427 PMCID: PMC6057921 DOI: 10.1038/s41467-018-05260-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/22/2018] [Indexed: 12/26/2022] Open
Abstract
Formation and turnover of branched actin networks underlies cell migration and other essential force-driven processes. Type I nucleation-promoting factors (NPFs) such as WASP recruit actin monomers to Arp2/3 complex to stimulate nucleation. In contrast, mechanisms of type II NPFs such as Abp1 (also known as HIP55 and Drebrin-like protein) are less well understood. Here, we use single-molecule analysis to investigate yeast Abp1 effects on Arp2/3 complex, and find that Abp1 strongly enhances Arp2/3-dependent branch nucleation by stabilizing Arp2/3 on sides of mother filaments. Abp1 binds dynamically to filament sides, with sub-second lifetimes, yet associates stably with branch junctions. Further, we uncover a role for Abp1 in protecting filament junctions from GMF-induced debranching by competing with GMF for Arp2/3 binding. These data, combined with EM structures of Abp1 dimers bound to Arp2/3 complex in two different conformations, expand our mechanistic understanding of type II NPFs. Abp1, a type II actin nucleation promoting factor, is a known component of branched actin networks but its mechanism remains poorly understood. Here, the authors find that Abp1 enhances Arp2/3-mediated actin branch formation, and blocks ‘debranching’ by GMF, making it a pro-branching factor.
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Riquelme M, Aguirre J, Bartnicki-García S, Braus GH, Feldbrügge M, Fleig U, Hansberg W, Herrera-Estrella A, Kämper J, Kück U, Mouriño-Pérez RR, Takeshita N, Fischer R. Fungal Morphogenesis, from the Polarized Growth of Hyphae to Complex Reproduction and Infection Structures. Microbiol Mol Biol Rev 2018; 82:e00068-17. [PMID: 29643171 PMCID: PMC5968459 DOI: 10.1128/mmbr.00068-17] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Jesús Aguirre
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Salomon Bartnicki-García
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Ursula Fleig
- Institute for Functional Genomics of Microorganisms, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Wilhelm Hansberg
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico
| | - Jörg Kämper
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ulrich Kück
- Ruhr University Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Bochum, Germany
| | - Rosa R Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Japan
| | - Reinhard Fischer
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
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Goode BL, Sweeney MO, Eskin JA. GMF as an Actin Network Remodeling Factor. Trends Cell Biol 2018; 28:749-760. [PMID: 29779865 DOI: 10.1016/j.tcb.2018.04.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 10/24/2022]
Abstract
Glia maturation factor (GMF) has recently been established as a regulator of the actin cytoskeleton with a unique role in remodeling actin network architecture. Conserved from yeast to mammals, GMF is one of five members of the ADF-H family of actin regulatory proteins, which includes ADF/cofilin, Abp1/Drebrin, Twinfilin, and Coactosin. GMF does not bind actin, but instead binds the Arp2/3 complex with high affinity. Through this association, GMF catalyzes the debranching of actin filament networks and inhibits actin nucleation by Arp2/3 complex. Here, we discuss GMF's emerging role in controlling actin filament spatial organization and dynamics underlying cell motility, endocytosis, and other biological processes. Further, we attempt to reconcile these functions with its earlier characterization as a cell differentiation factor.
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Affiliation(s)
- Bruce L Goode
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South Street, Waltham, MA 02454 USA.
| | - Meredith O Sweeney
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South Street, Waltham, MA 02454 USA
| | - Julian A Eskin
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South Street, Waltham, MA 02454 USA
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Identification of Wiskott-Aldrich syndrome protein (WASP) binding sites on the branched actin filament nucleator Arp2/3 complex. Proc Natl Acad Sci U S A 2018; 115:E1409-E1418. [PMID: 29386393 DOI: 10.1073/pnas.1716622115] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Arp2/3 complex nucleates branched actin filaments important for cellular motility and endocytosis. WASP family proteins are Arp2/3 complex activators that play multiple roles in branching nucleation, but little is known about the structural bases of these WASP functions, owing to an incomplete understanding of how WASP binds Arp2/3 complex. Recent data show WASP binds two sites, and biochemical and structural studies led to models in which the WASP C segment engages the barbed ends of the Arp3 and Arp2 subunits while the WASP A segment binds the back side of the complex on Arp3. However, electron microscopy reconstructions showed density for WASP inconsistent with these models on the opposite (front) side of Arp2/3 complex. Here we use chemical cross-linking and mass spectrometry (XL-MS) along with computational docking and structure-based mutational analysis to map the two WASP binding sites on the complex. Our data corroborate the barbed end and back side binding models and show one WASP binding site on Arp3, on the back side of the complex, and a second site on the bottom of the complex, spanning Arp2 and ARPC1. The XL-MS-identified cross-links rule out the front side binding model and show that the A segment of WASP binds along the bottom side of the ARPC1 subunit, instead of at the Arp2/ARPC1 interface, as suggested by FRET experiments. The identified binding sites support the Arp3 tail release model to explain WASP-mediated activating conformational changes in Arp2/3 complex and provide insight into the roles of WASP in branching nucleation.
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Popinako A, Antonov M, Dibrova D, Chemeris A, Sokolova OS. Analysis of the interactions between GMF and Arp2/3 complex in two binding sites by molecular dynamics simulation. Biochem Biophys Res Commun 2018; 496:529-535. [PMID: 29339159 DOI: 10.1016/j.bbrc.2018.01.080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 01/11/2018] [Indexed: 12/17/2022]
Abstract
The Arp2/3 complex plays a key role in nucleating actin filaments branching. The glia maturation factor (GMF) competes with activators for interacting with the Arp2/3 complex and initiates the debranching of actin filaments. In this study, we performed a comparative analysis of interactions between GMF and the Arp2/3 complex and identified new amino acid residues involved in GMF binding to the Arp2/3 complex at two separate sites, revealed by X-ray and single particle EM techniques. Using molecular dynamics simulations we demonstrated the quantitative and qualitative changes in hydrogen bonds upon binding with GMF. We identified the specific amino acid residues in GMF and Arp2/3 complex that stabilize the interactions and estimated the mean force profile for the GMF using umbrella sampling. Phylogenetic and structural analyses of the recently defined GMF binding site on the Arp3 subunit indicate a new mechanism for Arp2/3 complex inactivation that involves interactions between the Arp2/3 complex and GMF at two binding sites.
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Affiliation(s)
- A Popinako
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of RAS, 33 Leninsky Ave, bld. 2, Moscow, 119071, Russia
| | - M Antonov
- M.K. Ammosov North-Eastern Federal University, 58 Belinskiy str, suite 312, Yakutsk, 677980, Republic of Sakha (Yakutia), Russia
| | - D Dibrova
- Lomonosov Moscow State University, Faculty of Biology, 1 Leninskie gory, bld 12, Moscow, 119234, Russia
| | - A Chemeris
- Lomonosov Moscow State University, Faculty of Biology, 1 Leninskie gory, bld 12, Moscow, 119234, Russia
| | - O S Sokolova
- Lomonosov Moscow State University, Faculty of Biology, 1 Leninskie gory, bld 12, Moscow, 119234, Russia.
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29
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Molinie N, Gautreau A. The Arp2/3 Regulatory System and Its Deregulation in Cancer. Physiol Rev 2017; 98:215-238. [PMID: 29212790 DOI: 10.1152/physrev.00006.2017] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 02/07/2023] Open
Abstract
The Arp2/3 complex is an evolutionary conserved molecular machine that generates branched actin networks. When activated, the Arp2/3 complex contributes the actin branched junction and thus cross-links the polymerizing actin filaments in a network that exerts a pushing force. The different activators initiate branched actin networks at the cytosolic surface of different cellular membranes to promote their protrusion, movement, or scission in cell migration and membrane traffic. Here we review the structure, function, and regulation of all the direct regulators of the Arp2/3 complex that induce or inhibit the initiation of a branched actin network and that controls the stability of its branched junctions. Our goal is to present recent findings concerning novel inhibitory proteins or the regulation of the actin branched junction and place these in the context of what was previously known to provide a global overview of how the Arp2/3 complex is regulated in human cells. We focus on the human set of Arp2/3 regulators to compare normal Arp2/3 regulation in untransformed cells to the deregulation of the Arp2/3 system observed in patients affected by various cancers. In many cases, these deregulations promote cancer progression and have a direct impact on patient survival.
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Affiliation(s)
- Nicolas Molinie
- Ecole Polytechnique, Université Paris-Saclay, CNRS UMR 7654, Palaiseau, France; and Moscow Institute of Physics and Technology, Life Sciences Center, Dolgoprudny, Russia
| | - Alexis Gautreau
- Ecole Polytechnique, Université Paris-Saclay, CNRS UMR 7654, Palaiseau, France; and Moscow Institute of Physics and Technology, Life Sciences Center, Dolgoprudny, Russia
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30
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Popinako AV, Antonov MY, Chemeris AS, Shaitan KV, Sokolova OS. Analysis of the Interactions between Arp2/3 Complex and an Inhibitor Arpin by Molecular Dynamics Simulation. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917060203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Levin R, Grinstein S, Canton J. The life cycle of phagosomes: formation, maturation, and resolution. Immunol Rev 2017; 273:156-79. [PMID: 27558334 DOI: 10.1111/imr.12439] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phagocytosis, the regulated uptake of large particles (>0.5 μm in diameter), is essential for tissue homeostasis and is also an early, critical component of the innate immune response. Phagocytosis can be conceptually divided into three stages: phagosome, formation, maturation, and resolution. Each of these involves multiple reactions that require exquisite spatial and temporal orchestration. The molecular events underlying these stages are being unraveled and the current state of knowledge is briefly summarized in this article.
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Affiliation(s)
- Roni Levin
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
| | - Johnathan Canton
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada
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Abstract
Schizophrenia is a severe psychiatric disorder that is characterized by a wide array of symptoms and a complex neuropathology. A well-characterized neurobiological feature of schizophrenia is abnormal synaptic plasticity, although the mechanisms underlying this are not fully understood. Numerous studies have demonstrated a link between proper functioning of the cytoskeleton and synaptic plasticity. The actin-related protein-2/3 (Arp2/3) complex is responsible for the nucleation of new actin filaments and elongation of existing actin filaments and is thus crucial to cytoskeletal dynamics, especially actin polymerization and organization. To determine whether the Arp2/3 complex is abnormally expressed in schizophrenia, we measured the protein expression of Arp2 and Arp3, as well as Arp2/3 complex binding partners and associated proteins including cortactin, neuronal-Wiskott-Aldrich syndrome protein (WASP), WASP-family verprolin homologous protein 1 (WAVE1), and Abelson interactor 1 (Abi1) in the superior temporal gyrus of paired schizophrenia and comparison participants. No changes were found in Arp2, Arp3, neuronal-WASP, WAVE1, or Abi1. However, all three isoforms of cortactin were decreased in schizophrenia. Specifically, the 62 kDa isoform was decreased by 43%; the 71 kDa isoform was decreased by 32%; and the 58 kDa isoform was decreased by 35%. Cortactin regulates branching of filamentous actin through its binding and activation of the Arp2/3 complex, and it is thus critical to the formation of stable actin networks. These findings contribute to a growing body of evidence implicating altered cytoskeletal dynamics in schizophrenia.
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33
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Sokolova OS, Chemeris A, Guo S, Alioto SL, Gandhi M, Padrick S, Pechnikova E, David V, Gautreau A, Goode BL. Structural Basis of Arp2/3 Complex Inhibition by GMF, Coronin, and Arpin. J Mol Biol 2016; 429:237-248. [PMID: 27939292 DOI: 10.1016/j.jmb.2016.11.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/23/2016] [Accepted: 11/28/2016] [Indexed: 10/20/2022]
Abstract
The evolutionarily conserved Arp2/3 complex plays a central role in nucleating the branched actin filament arrays that drive cell migration, endocytosis, and other processes. To better understand Arp2/3 complex regulation, we used single-particle electron microscopy to compare the structures of Arp2/3 complex bound to three different inhibitory ligands: glia maturation factor (GMF), Coronin, and Arpin. Although the three inhibitors have distinct binding sites on Arp2/3 complex, they each induced an "open" nucleation-inactive conformation. Coronin promoted a standard (previously described) open conformation of Arp2/3 complex, with the N-terminal β-propeller domain of Coronin positioned near the p35/ARPC2 subunit of Arp2/3 complex. GMF induced two distinct open conformations of Arp2/3 complex, which correlated with the two suggested binding sites for GMF. Furthermore, GMF synergized with Coronin in inhibiting actin nucleation by Arp2/3 complex. Arpin, which uses VCA-related acidic (A) motifs to interact with the Arp2/3 complex, induced the standard open conformation, and two new masses appeared at positions near Arp2 and Arp3. Furthermore, Arpin showed additive inhibitory effects on Arp2/3 complex with Coronin and GMF. Together, these data suggest that Arp2/3 complex conformation is highly polymorphic and that its activities can be controlled combinatorially by different inhibitory ligands.
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Affiliation(s)
- Olga S Sokolova
- Department of Biology, Moscow M.V. Lomonosov University, Moscow 119234, Russia
| | - Angelina Chemeris
- Department of Biology, Moscow M.V. Lomonosov University, Moscow 119234, Russia; Ecole Polytechnique, CNRS UMR7654, Palaiseau 91120, France
| | - Siyang Guo
- Department of Biology, Brandeis University, Waltham, MA 02453, USA
| | | | - Meghal Gandhi
- Department of Biology, Brandeis University, Waltham, MA 02453, USA
| | - Shae Padrick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | | | - Violaine David
- Ecole Polytechnique, CNRS UMR7654, Palaiseau 91120, France
| | | | - Bruce L Goode
- Department of Biology, Brandeis University, Waltham, MA 02453, USA.
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Rodnick-Smith M, Liu SL, Balzer CJ, Luan Q, Nolen BJ. Identification of an ATP-controlled allosteric switch that controls actin filament nucleation by Arp2/3 complex. Nat Commun 2016; 7:12226. [PMID: 27417392 PMCID: PMC4947185 DOI: 10.1038/ncomms12226] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 06/10/2016] [Indexed: 01/07/2023] Open
Abstract
Nucleation of branched actin filaments by Arp2/3 complex is tightly regulated to control actin assembly in cells. Arp2/3 complex activation involves conformational changes brought about by ATP, Nucleation Promoting Factor (NPF) proteins, actin filaments and NPF-recruited actin monomers. To understand how these factors promote activation, we must first understand how the complex is held inactive in their absence. Here we demonstrate that the Arp3 C-terminal tail is a structural switch that prevents Arp2/3 complex from adopting an active conformation. The interaction between the tail and a hydrophobic groove in Arp3 blocks movement of Arp2 and Arp3 into an activated filament-like (short pitch) conformation. Our data indicate ATP binding destabilizes this interaction via an allosteric link between the Arp3 nucleotide cleft and the hydrophobic groove, thereby promoting the short-pitch conformation. Our results help explain how Arp2/3 complex is locked in an inactive state without activators and how autoinhibition is relieved.
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Affiliation(s)
- Max Rodnick-Smith
- Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, USA
| | - Su-Ling Liu
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | - Connor J Balzer
- Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, USA
| | - Qing Luan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | - Brad J Nolen
- Institute of Molecular Biology and Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, USA
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Role and structural mechanism of WASP-triggered conformational changes in branched actin filament nucleation by Arp2/3 complex. Proc Natl Acad Sci U S A 2016; 113:E3834-43. [PMID: 27325766 DOI: 10.1073/pnas.1517798113] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Arp2/3 (Actin-related proteins 2/3) complex is activated by WASP (Wiskott-Aldrich syndrome protein) family proteins to nucleate branched actin filaments that are important for cellular motility. WASP recruits actin monomers to the complex and stimulates movement of Arp2 and Arp3 into a "short-pitch" conformation that mimics the arrangement of actin subunits within filaments. The relative contribution of these functions in Arp2/3 complex activation and the mechanism by which WASP stimulates the conformational change have been unknown. We purified budding yeast Arp2/3 complex held in or near the short-pitch conformation by an engineered covalent cross-link to determine if the WASP-induced conformational change is sufficient for activity. Remarkably, cross-linked Arp2/3 complex bypasses the need for WASP in activation and is more active than WASP-activated Arp2/3 complex. These data indicate that stimulation of the short-pitch conformation is the critical activating function of WASP and that monomer delivery is not a fundamental requirement for nucleation but is a specific requirement for WASP-mediated activation. During activation, WASP limits nucleation rates by releasing slowly from nascent branches. The cross-linked complex is inhibited by WASP's CA region, even though CA potently stimulates cross-linking, suggesting that slow WASP detachment masks the activating potential of the short-pitch conformational switch. We use structure-based mutations and WASP-Arp fusion chimeras to determine how WASP stimulates movement toward the short-pitch conformation. Our data indicate that WASP displaces the autoinhibitory Arp3 C-terminal tail from a hydrophobic groove at Arp3's barbed end to destabilize the inactive state, providing a mechanism by which WASP stimulates the short-pitch conformation and activates Arp2/3 complex.
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Recurrent viral infections associated with a homozygous CORO1A mutation that disrupts oligomerization and cytoskeletal association. J Allergy Clin Immunol 2015; 137:879-88.e2. [PMID: 26476480 DOI: 10.1016/j.jaci.2015.08.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/26/2015] [Accepted: 08/04/2015] [Indexed: 01/18/2023]
Abstract
BACKGROUND Coronin-1A (CORO1A) is a regulator of actin dynamics important for T-cell homeostasis. CORO1A deficiency causes T(-)B(+) natural killer-positive severe combined immunodeficiency or T-cell lymphopenia with severe viral infections. However, because all known human mutations in CORO1A abrogate protein expression, the role of the protein's functional domains in host immunity is unknown. OBJECTIVE We sought to identify the cause of the primary immunodeficiency in 2 young adult siblings with a history of disseminated varicella, cutaneous warts, and CD4(+) T-cell lymphopenia. METHODS We performed immunologic, genetic, and biochemical studies in the patients, family members, and healthy control subjects. RESULTS Both patients had CD4(+) T-cell lymphopenia and decreased lymphocyte proliferation to mitogens. IgG, IgM, IgA, and specific antibody responses were normal. Whole-genome sequencing identified a homozygous frameshift mutation in CORO1A disrupting the last 2 C-terminal domains by replacing 61 amino acids with a novel 91-amino-acid sequence. The CORO1A(S401fs) mutant was expressed in the patients' lymphocytes at a level comparable with that of wild-type CORO1A in normal lymphocytes but did not oligomerize and had impaired cytoskeletal association. CORO1A(S401fs) was associated with increased filamentous actin accumulation in T cells, severely defective thymic output, and impaired T-cell survival but normal calcium flux and cytotoxicity, demonstrating the importance of CORO1A oligomerization and subcellular localization in T-cell homeostasis. CONCLUSIONS We describe a truncating mutation in CORO1A that permits protein expression and survival into young adulthood. Our studies demonstrate the importance of intact CORO1A C-terminal domains in thymic egress and T-cell survival, as well as in defense against viral pathogens.
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Urbanek AN, Allwood EG, Smith AP, Booth WI, Ayscough KR. Distinct Actin and Lipid Binding Sites in Ysc84 Are Required during Early Stages of Yeast Endocytosis. PLoS One 2015; 10:e0136732. [PMID: 26312755 PMCID: PMC4552428 DOI: 10.1371/journal.pone.0136732] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/08/2015] [Indexed: 11/18/2022] Open
Abstract
During endocytosis in S. cerevisiae, actin polymerization is proposed to provide the driving force for invagination against the effects of turgor pressure. In previous studies, Ysc84 was demonstrated to bind actin through a conserved N-terminal domain. However, full length Ysc84 could only bind actin when its C-terminal SH3 domain also bound to the yeast WASP homologue Las17. Live cell-imaging has revealed that Ysc84 localizes to endocytic sites after Las17/WASP but before other known actin binding proteins, suggesting it is likely to function at an early stage of membrane invagination. While there are homologues of Ysc84 in other organisms, including its human homologue SH3yl-1, little is known of its mode of interaction with actin or how this interaction affects actin filament dynamics. Here we identify key residues involved both in Ysc84 actin and lipid binding, and demonstrate that its actin binding activity is negatively regulated by PI(4,5)P2. Ysc84 mutants defective in their lipid or actin-binding interaction were characterized in vivo. The abilities of Ysc84 to bind Las17 through its C-terminal SH3 domain, or to actin and lipid through the N-terminal domain were all shown to be essential in order to rescue temperature sensitive growth in a strain requiring YSC84 expression. Live cell imaging in strains with fluorescently tagged endocytic reporter proteins revealed distinct phenotypes for the mutants indicating the importance of these interactions for regulating key stages of endocytosis.
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Affiliation(s)
- Agnieszka N. Urbanek
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, United Kingdom
| | - Ellen G. Allwood
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, United Kingdom
| | - Adam P. Smith
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, United Kingdom
| | - Wesley I. Booth
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, United Kingdom
| | - Kathryn R. Ayscough
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, United Kingdom
- * E-mail:
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Ydenberg CA, Johnston A, Weinstein J, Bellavance D, Jansen S, Goode BL. Combinatorial genetic analysis of a network of actin disassembly-promoting factors. Cytoskeleton (Hoboken) 2015; 72:349-61. [PMID: 26147656 PMCID: PMC5014199 DOI: 10.1002/cm.21231] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 12/12/2022]
Abstract
The patterning of actin cytoskeleton structures in vivo is a product of spatially and temporally regulated polymer assembly balanced by polymer disassembly. While in recent years our understanding of actin assembly mechanisms has grown immensely, our knowledge of actin disassembly machinery and mechanisms has remained comparatively sparse. Saccharomyces cerevisiae is an ideal system to tackle this problem, both because of its amenabilities to genetic manipulation and live‐cell imaging and because only a single gene encodes each of the core disassembly factors: cofilin (COF1), Srv2/CAP (SRV2), Aip1 (AIP1), GMF (GMF1/AIM7), coronin (CRN1), and twinfilin (TWF1). Among these six factors, only the functions of cofilin are essential and have been well defined. Here, we investigated the functions of the nonessential actin disassembly factors by performing genetic and live‐cell imaging analyses on a combinatorial set of isogenic single, double, triple, and quadruple mutants in S. cerevisiae. Our results show that each disassembly factor makes an important contribution to cell viability, actin organization, and endocytosis. Further, our data reveal new relationships among these factors, providing insights into how they work together to orchestrate actin turnover. Finally, we observe specific combinations of mutations that are lethal, e.g., srv2Δ aip1Δ and srv2Δ crn1Δ twf1Δ, demonstrating that while cofilin is essential, it is not sufficient in vivo, and that combinations of the other disassembly factors perform vital functions. © 2015 The Authors. Cytoskeleton Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Casey A Ydenberg
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
| | - Adam Johnston
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
| | - Jaclyn Weinstein
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
| | - Danielle Bellavance
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
| | - Silvia Jansen
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, Massachusetts, 02454
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Abstract
Development of a functional peripheral nervous system requires axons to rapidly innervate and arborize into final target organs and then slow but not halt their growth to establish stable connections while keeping pace with organ growth. Here we examine the role of the NGF-TrkA effector protein, Coronin-1, on postganglionic sympathetic neuron final target innervation. In the absence of Coronin-1 we find that NGF-TrkA-PI3K signaling drives robust axon growth and branching in part by suppressing GSK3β. In contrast, the presence of Coronin-1 (wild-type neurons) suppresses but does not halt NGF-TrkA-dependent growth and branching. This relative suppression in axon growth behaviors is due to Coronin-1-dependent calcium release via PLC-γ1 signaling, which releases PI3K-dependent suppression of GSK3β. Finally, we demonstrate that Coro1a(-/-) mice display sympathetic axon overgrowth and overbranching phenotypes in the developing heart. Together with previous work demonstrating the Coronin-1 expression is NGF dependent, this work suggests that periods before and after NGF-TrkA-induced Coronin-1 expression (and likely other factors) defines two distinct axon growth states, which are critical for proper circuit formation in the sympathetic nervous system.
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Punwani D, Pelz B, Yu J, Arva NC, Schafernak K, Kondratowicz K, Makhija M, Puck JM. Coronin-1A: immune deficiency in humans and mice. J Clin Immunol 2015; 35:100-7. [PMID: 25666293 DOI: 10.1007/s10875-015-0130-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/13/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Divya Punwani
- Department of Pediatrics, University of California San Francisco and UCSF Benioff Children's Hospital, Box 0519, 513 Parnassus Avenue, HSE 301A, San Francisco, CA, 94143-0519, USA
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Abstract
Endocytosis, the process whereby the plasma membrane invaginates to form vesicles, is essential for bringing many substances into the cell and for membrane turnover. The mechanism driving clathrin-mediated endocytosis (CME) involves > 50 different protein components assembling at a single location on the plasma membrane in a temporally ordered and hierarchal pathway. These proteins perform precisely choreographed steps that promote receptor recognition and clustering, membrane remodeling, and force-generating actin-filament assembly and turnover to drive membrane invagination and vesicle scission. Many critical aspects of the CME mechanism are conserved from yeast to mammals and were first elucidated in yeast, demonstrating that it is a powerful system for studying endocytosis. In this review, we describe our current mechanistic understanding of each step in the process of yeast CME, and the essential roles played by actin polymerization at these sites, while providing a historical perspective of how the landscape has changed since the preceding version of the YeastBook was published 17 years ago (1997). Finally, we discuss the key unresolved issues and where future studies might be headed.
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Affiliation(s)
- Bruce L Goode
- Brandeis University, Department of Biology, Rosenstiel Center, Waltham, Massachusetts 02454
| | - Julian A Eskin
- Brandeis University, Department of Biology, Rosenstiel Center, Waltham, Massachusetts 02454
| | - Beverly Wendland
- The Johns Hopkins University, Department of Biology, Baltimore, Maryland 21218
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Sweeney MO, Collins A, Padrick SB, Goode BL. A novel role for WAVE1 in controlling actin network growth rate and architecture. Mol Biol Cell 2014; 26:495-505. [PMID: 25473116 PMCID: PMC4310740 DOI: 10.1091/mbc.e14-10-1477] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
A novel functional role for WAVE1 is found that is lacking in N-WASP and WAVE2. Through its unique WH2 domain, WAVE1 dramatically reduces the rate of actin filament elongation independently of its interactions with the Arp2/3 complex. These findings help explain how cells build actin networks with distinct geometries and growth rates. Branched actin filament networks in cells are assembled through the combined activities of Arp2/3 complex and different WASP/WAVE proteins. Here we used TIRF and electron microscopy to directly compare for the first time the assembly kinetics and architectures of actin filament networks produced by Arp2/3 complex and dimerized VCA regions of WAVE1, WAVE2, or N-WASP. WAVE1 produced strikingly different networks from WAVE2 or N-WASP, which comprised unexpectedly short filaments. Further analysis showed that the WAVE1-specific activity stemmed from an inhibitory effect on filament elongation both in the presence and absence of Arp2/3 complex, which was observed even at low stoichiometries of WAVE1 to actin monomers, precluding an effect from monomer sequestration. Using a series of VCA chimeras, we mapped the elongation inhibitory effects of WAVE1 to its WH2 (“V”) domain. Further, mutating a single conserved lysine residue potently disrupted WAVE1's inhibitory effects. Taken together, our results show that WAVE1 has unique activities independent of Arp2/3 complex that can govern both the growth rates and architectures of actin filament networks. Such activities may underlie previously observed differences between the cellular functions of WAVE1 and WAVE2.
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Affiliation(s)
- Meredith O Sweeney
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Agnieszka Collins
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Shae B Padrick
- Howard Hughes Medical Institute and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bruce L Goode
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454;
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Terzi YK, Kocaefe YC, Ayter S. Coronin 1A inhibits neurite outgrowth in PC12 cells. Neurosci Lett 2014; 582:38-42. [PMID: 25179994 DOI: 10.1016/j.neulet.2014.08.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/21/2014] [Accepted: 08/25/2014] [Indexed: 11/30/2022]
Abstract
Regenerative response to central nervous system damage in mammals is limited because of inhibitor signals which consist of myelin associated inhibitor proteins and chondroitin sulfate proteoglycans. Inhibitor signals mainly affect cytoskeleton elements which are important for axonal sprouting and neurite outgrowth. Coronin 1A is an actin cytoskeleton associated protein. Coronin 1A shows its effect on actin cytoskeleton through binding to the Arp2/3 complex which is a key nucleator of actin polymerization and regulates its activation on actin cytoskeleton. Coronin 1A-Arp2/3 interaction is regulated by phosphorylation of Coronin 1A from the C and N terminal region. Thus, Coronin 1A-Arp2/3 complex is one of the targets of inhibitory signaling cascades. The aim of this study was to investigate the effect of Coronin 1A on neurite outgrowth in PC12 cells in vitro. The results showed that Coronin 1A is expressed in differentiated PC12 cells and localized along axonal sprouting region of the neurites. Other results showed that overexpression of Coronin 1A in PC12 cells effects neurite outgrowth. Neurite lengths of the Coronin 1A overexpressing PC12 cells were lower than the untransfected (p<0.001) and control transfected (p=0.002) PC12 cells. These results indicate that Coronin 1A has an inhibitory effect on neurite outgrowth in vitro.
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Affiliation(s)
- Yunus Kasim Terzi
- Hacettepe University, Faculty of Medicine, Department of Medical Biology, Sihhiye, 06100, Ankara, Turkey
| | - Yusuf Cetin Kocaefe
- Hacettepe University, Faculty of Medicine, Department of Medical Biology, Sihhiye, 06100, Ankara, Turkey
| | - Sukriye Ayter
- Hacettepe University, Faculty of Medicine, Department of Medical Biology, Sihhiye, 06100, Ankara, Turkey.
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Lamprecht R. The actin cytoskeleton in memory formation. Prog Neurobiol 2014; 117:1-19. [DOI: 10.1016/j.pneurobio.2014.02.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 01/21/2023]
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Exploration of the dynamic properties of protein complexes predicted from spatially constrained protein-protein interaction networks. PLoS Comput Biol 2014; 10:e1003654. [PMID: 24874694 PMCID: PMC4038459 DOI: 10.1371/journal.pcbi.1003654] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 04/19/2014] [Indexed: 11/19/2022] Open
Abstract
Protein complexes are not static, but rather highly dynamic with subunits that undergo 1-dimensional diffusion with respect to each other. Interactions within protein complexes are modulated through regulatory inputs that alter interactions and introduce new components and deplete existing components through exchange. While it is clear that the structure and function of any given protein complex is coupled to its dynamical properties, it remains a challenge to predict the possible conformations that complexes can adopt. Protein-fragment Complementation Assays detect physical interactions between protein pairs constrained to ≤8 nm from each other in living cells. This method has been used to build networks composed of 1000s of pair-wise interactions. Significantly, these networks contain a wealth of dynamic information, as the assay is fully reversible and the proteins are expressed in their natural context. In this study, we describe a method that extracts this valuable information in the form of predicted conformations, allowing the user to explore the conformational landscape, to search for structures that correlate with an activity state, and estimate the abundance of conformations in the living cell. The generator is based on a Markov Chain Monte Carlo simulation that uses the interaction dataset as input and is constrained by the physical resolution of the assay. We applied this method to an 18-member protein complex composed of the seven core proteins of the budding yeast Arp2/3 complex and 11 associated regulators and effector proteins. We generated 20,480 output structures and identified conformational states using principle component analysis. We interrogated the conformation landscape and found evidence of symmetry breaking, a mixture of likely active and inactive conformational states and dynamic exchange of the core protein Arc15 between core and regulatory components. Our method provides a novel tool for prediction and visualization of the hidden dynamics within protein interaction networks. Cells are complex dynamic systems, and a central challenge in modern cell biology is to capture information about interactions between the molecules underlying cellular processes. Proteins rarely act alone; more often they form functional partnerships that can specify the timing and/or location of activity. These partnerships are subject to dynamic changes, and thus protein interactions within complexes undergo continuous transitions. Genetic and biochemical evidence suggest that regulation or depletion of a single protein can alter the stability and activity of an entire protein complex. Experimental approaches that detect interactions within living cells provide critical information for the dynamical system that protein complexes represent; yet complexes are often depicted as static 2-dimensional networks. We have built a system that projects in vivo protein interaction datasets as 3-dimensional virtual protein complexes. By using this method to approximate the diffusion of complex components, we can predict transient conformational states and estimate their abundance in living cells. Our method offers biologists a framework to correlate experimental phenotypes with predicted complex dynamics such as short or long-range effects of a single perturbation to the function of the whole ensemble.
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46
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Truong D, Copeland JW, Brumell JH. Bacterial subversion of host cytoskeletal machinery: hijacking formins and the Arp2/3 complex. Bioessays 2014; 36:687-96. [PMID: 24849003 DOI: 10.1002/bies.201400038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The host actin nucleation machinery is subverted by many bacterial pathogens to facilitate their entry, motility, replication, and survival. The majority of research conducted in the past primarily focused on exploitation of a host actin nucleator, the Arp2/3 complex, by bacterial pathogens. Recently, new studies have begun to explore the role of formins, another family of host actin nucleators, in bacterial pathogenesis. This review provides an overview of recent advances in the study of the exploitation of the Arp2/3 complex and formins by bacterial pathogens. Secreted bacterial effector proteins seem to manipulate the regulation of these actin nucleators or functionally mimic them to drive bacterial entry, motility and survival within host cells. An enhanced understanding of how formins are exploited will provide us with greater insight into how a fundamental eurkaryotic cellular process is utilized by bacteria and will also advance our knowledge of host-pathogen interactions.
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Affiliation(s)
- Dorothy Truong
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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47
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Zahm JA, Padrick SB, Chen Z, Pak CW, Yunus AA, Henry L, Tomchick DR, Chen Z, Rosen MK. The bacterial effector VopL organizes actin into filament-like structures. Cell 2013; 155:423-34. [PMID: 24120140 DOI: 10.1016/j.cell.2013.09.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 07/22/2013] [Accepted: 09/11/2013] [Indexed: 12/28/2022]
Abstract
VopL is an effector protein from Vibrio parahaemolyticus that nucleates actin filaments. VopL consists of a VopL C-terminal domain (VCD) and an array of three WASP homology 2 (WH2) motifs. Here, we report the crystal structure of the VCD dimer bound to actin. The VCD organizes three actin monomers in a spatial arrangement close to that found in the canonical actin filament. In this arrangement, WH2 motifs can be modeled into the binding site of each actin without steric clashes. The data suggest a mechanism of nucleation wherein VopL creates filament-like structures, organized by the VCD with monomers delivered by the WH2 array, that can template addition of new subunits. Similarities with Arp2/3 complex and formin proteins suggest that organization of monomers into filament-like structures is a general and central feature of actin nucleation.
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Affiliation(s)
- Jacob A Zahm
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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48
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Tang Z, Araysi LM, Fathallah-Shaykh HM. c-Src and neural Wiskott-Aldrich syndrome protein (N-WASP) promote low oxygen-induced accelerated brain invasion by gliomas. PLoS One 2013; 8:e75436. [PMID: 24069415 PMCID: PMC3777891 DOI: 10.1371/journal.pone.0075436] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/16/2013] [Indexed: 11/22/2022] Open
Abstract
Malignant gliomas remain associated with poor prognosis and high morbidity because of their ability to invade the brain; furthermore, human gliomas exhibit a phenotype of accelerated brain invasion in response to anti-angiogenic drugs. Here, we study 8 human glioblastoma cell lines; U251, U87, D54 and LN229 show accelerated motility in low ambient oxygen. Src inhibition by Dasatinib abrogates this phenotype. Molecular discovery and validation studies evaluate 46 molecules related to motility or the src pathway in U251 cells. Demanding that the molecular changes induced by low ambient oxygen are reversed by Dasatinib in U251 cells, identifies neural Wiskott-Aldrich syndrome protein (NWASP), Focal adhesion Kinase (FAK), -Catenin, and Cofilin. However, only Src-mediated NWASP phosphorylation distinguishes the four cell lines that exhibit enhanced motility in low ambient oxygen. Downregulating c-Src or NWASP by RNA interference abrogates the low-oxygen-induced enhancement in motility by in vitro assays and in organotypic brain slice cultures. The findings support the idea that c-Src and NWASP play key roles in mediating the molecular pathogenesis of low oxygen-induced accelerated brain invasion by gliomas.
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Affiliation(s)
- Zhuo Tang
- Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Lita M. Araysi
- Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Hassan M Fathallah-Shaykh
- Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Mathematics, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Mechanical Engineering, The University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- The UAB Comprehensive Neuroscience Center, Birmingham, Alabama, United States of America
- The UAB Comprehensive Cancer Center, Birmingham, Alabama, United States of America
- * E-mail:
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Smith BA, Padrick SB, Doolittle LK, Daugherty-Clarke K, Corrêa IR, Xu MQ, Goode BL, Rosen MK, Gelles J. Three-color single molecule imaging shows WASP detachment from Arp2/3 complex triggers actin filament branch formation. eLife 2013; 2:e01008. [PMID: 24015360 PMCID: PMC3762362 DOI: 10.7554/elife.01008] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/29/2013] [Indexed: 01/22/2023] Open
Abstract
During cell locomotion and endocytosis, membrane-tethered WASP proteins stimulate actin filament nucleation by the Arp2/3 complex. This process generates highly branched arrays of filaments that grow toward the membrane to which they are tethered, a conflict that seemingly would restrict filament growth. Using three-color single-molecule imaging in vitro we revealed how the dynamic associations of Arp2/3 complex with mother filament and WASP are temporally coordinated with initiation of daughter filament growth. We found that WASP proteins dissociated from filament-bound Arp2/3 complex prior to new filament growth. Further, mutations that accelerated release of WASP from filament-bound Arp2/3 complex proportionally accelerated branch formation. These data suggest that while WASP promotes formation of pre-nucleation complexes, filament growth cannot occur until it is triggered by WASP release. This provides a mechanism by which membrane-bound WASP proteins can stimulate network growth without restraining it. DOI:http://dx.doi.org/10.7554/eLife.01008.001.
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Affiliation(s)
- Benjamin A Smith
- Department of Biochemistry, Brandeis University, Waltham, United States
| | - Shae B Padrick
- Department of Biophysics, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Lynda K Doolittle
- Department of Biophysics, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Karen Daugherty-Clarke
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, United States
- Department of Biology, Brandeis University, Waltham, United States
| | | | | | - Bruce L Goode
- Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, United States
- Department of Biology, Brandeis University, Waltham, United States
| | - Michael K Rosen
- Department of Biophysics, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jeff Gelles
- Department of Biochemistry, Brandeis University, Waltham, United States
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Abstract
Several bacterial pathogens, including Listeria monocytogenes, Shigella flexneri and Rickettsia spp., have evolved mechanisms to actively spread within human tissues. Spreading is initiated by the pathogen-induced recruitment of host filamentous (F)-actin. F-actin forms a tail behind the microbe, propelling it through the cytoplasm. The motile pathogen then encounters the host plasma membrane, forming a bacterium-containing protrusion that is engulfed by an adjacent cell. Over the past two decades, much progress has been made in elucidating mechanisms of F-actin tail formation. Listeria and Shigella produce tails of branched actin filaments by subverting the host Arp2/3 complex. By contrast, Rickettsia forms tails with linear actin filaments through a bacterial mimic of eukaryotic formins. Compared with F-actin tail formation, mechanisms controlling bacterial protrusions are less well understood. However, recent findings have highlighted the importance of pathogen manipulation of host cell–cell junctions in spread. Listeria produces a soluble protein that enhances bacterial protrusions by perturbing tight junctions. Shigella protrusions are engulfed through a clathrin-mediated pathway at ‘tricellular junctions’—specialized membrane regions at the intersection of three epithelial cells. This review summarizes key past findings in pathogen spread, and focuses on recent developments in actin-based motility and the formation and internalization of bacterial protrusions.
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Affiliation(s)
- Keith Ireton
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
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