1
|
Bucki R, Wang YH, Yang C, Kandy SK, Fatunmbi O, Bradley R, Pogoda K, Svitkina T, Radhakrishnan R, Janmey PA. Lateral distribution of phosphatidylinositol 4,5-bisphosphate in membranes regulates formin- and ARP2/3-mediated actin nucleation. J Biol Chem 2019; 294:4704-4722. [PMID: 30692198 DOI: 10.1074/jbc.ra118.005552] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/13/2019] [Indexed: 11/06/2022] Open
Abstract
Spatial and temporal control of actin polymerization is fundamental for many cellular processes, including cell migration, division, vesicle trafficking, and response to agonists. Many actin-regulatory proteins interact with phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and are either activated or inactivated by local PI(4,5)P2 concentrations that form transiently at the cytoplasmic face of cell membranes. The molecular mechanisms of these interactions and how the dozens of PI(4,5)P2-sensitive actin-binding proteins are selectively recruited to membrane PI(4,5)P2 pools remains undefined. Using a combination of biochemical, imaging, and cell biologic studies, combined with molecular dynamics and analytical theory, we test the hypothesis that the lateral distribution of PI(4,5)P2 within lipid membranes and native plasma membranes alters the capacity of PI(4,5)P2 to nucleate actin assembly in brain and neutrophil extracts and show that activities of formins and the Arp2/3 complex respond to PI(4,5)P2 lateral distribution. Simulations and analytical theory show that cholesterol promotes the cooperative interaction of formins with multiple PI(4,5)P2 headgroups in the membrane to initiate actin nucleation. Masking PI(4,5)P2 with neomycin or disrupting PI(4,5)P2 domains in the plasma membrane by removing cholesterol decreases the ability of these membranes to nucleate actin assembly in cytoplasmic extracts.
Collapse
Affiliation(s)
- Robert Bucki
- From the Departments of Physiology, .,the Department of Microbiological and Nanobiomedical Engineering, Medical University of Białystok, 15-089 Białystok, Poland
| | - Yu-Hsiu Wang
- Chemistry.,the Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | | | - Sreeja Kutti Kandy
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Ololade Fatunmbi
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Ryan Bradley
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Katarzyna Pogoda
- From the Departments of Physiology.,the Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Kraków, Poland, and
| | | | - Ravi Radhakrishnan
- Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Paul A Janmey
- From the Departments of Physiology.,the Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| |
Collapse
|
2
|
Janssen E, Tohme M, Hedayat M, Leick M, Kumari S, Ramesh N, Massaad MJ, Ullas S, Azcutia V, Goodnow CC, Randall KL, Qiao Q, Wu H, Al-Herz W, Cox D, Hartwig J, Irvine DJ, Luscinskas FW, Geha RS. A DOCK8-WIP-WASp complex links T cell receptors to the actin cytoskeleton. J Clin Invest 2016; 126:3837-3851. [PMID: 27599296 DOI: 10.1172/jci85774] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 07/28/2016] [Indexed: 11/17/2022] Open
Abstract
Wiskott-Aldrich syndrome (WAS) is associated with mutations in the WAS protein (WASp), which plays a critical role in the initiation of T cell receptor-driven (TCR-driven) actin polymerization. The clinical phenotype of WAS includes susceptibility to infection, allergy, autoimmunity, and malignancy and overlaps with the symptoms of dedicator of cytokinesis 8 (DOCK8) deficiency, suggesting that the 2 syndromes share common pathogenic mechanisms. Here, we demonstrated that the WASp-interacting protein (WIP) bridges DOCK8 to WASp and actin in T cells. We determined that the guanine nucleotide exchange factor activity of DOCK8 is essential for the integrity of the subcortical actin cytoskeleton as well as for TCR-driven WASp activation, F-actin assembly, immune synapse formation, actin foci formation, mechanotransduction, T cell transendothelial migration, and homing to lymph nodes, all of which also depend on WASp. These results indicate that DOCK8 and WASp are in the same signaling pathway that links TCRs to the actin cytoskeleton in TCR-driven actin assembly. Further, they provide an explanation for similarities in the clinical phenotypes of WAS and DOCK8 deficiency.
Collapse
|
3
|
Janjanam J, Chandaka GK, Kotla S, Rao GN. PLCβ3 mediates cortactin interaction with WAVE2 in MCP1-induced actin polymerization and cell migration. Mol Biol Cell 2015; 26:4589-606. [PMID: 26490115 PMCID: PMC4678017 DOI: 10.1091/mbc.e15-08-0570] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/13/2015] [Indexed: 12/24/2022] Open
Abstract
Monocyte chemotactic protein 1 (MCP1) stimulates vascular smooth muscle cell (VSMC) migration in vascular wall remodeling. However, the mechanisms underlying MCP1-induced VSMC migration have not been understood. Here we identify the signaling pathway associated with MCP1-induced human aortic smooth muscle cell (HASMC) migration. MCP1, a G protein-coupled receptor agonist, activates phosphorylation of cortactin on S405 and S418 residues in a time-dependent manner, and inhibition of its phosphorylation attenuates MCP1-induced HASMC G-actin polymerization, F-actin stress fiber formation, and migration. Cortactin phosphorylation on S405/S418 is found to be critical for its interaction with WAVE2, a member of the WASP family of cytoskeletal regulatory proteins required for cell migration. In addition, the MCP1-induced cortactin phosphorylation is dependent on PLCβ3-mediated PKCδ activation, and siRNA-mediated down-regulation of either of these molecules prevents cortactin interaction with WAVE2, affecting G-actin polymerization, F-actin stress fiber formation, and HASMC migration. Upstream, MCP1 activates CCR2 and Gαq/11 in a time-dependent manner, and down-regulation of their levels attenuates MCP1-induced PLCβ3 and PKCδ activation, cortactin phosphorylation, cortactin-WAVE2 interaction, G-actin polymerization, F-actin stress fiber formation, and HASMC migration. Together these findings demonstrate that phosphorylation of cortactin on S405 and S418 residues is required for its interaction with WAVE2 in MCP1-induced cytoskeleton remodeling, facilitating HASMC migration.
Collapse
Affiliation(s)
- Jagadeesh Janjanam
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Giri Kumar Chandaka
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Sivareddy Kotla
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| |
Collapse
|
4
|
Park MS, Kim NH, Kang CW, Oh CW, Kim GD. Antimetastatic Effects of Gambogic Acid are Mediated via the Actin Cytoskeleton and NF-κB Pathways in SK-HEP1 Cells. Drug Dev Res 2015; 76:132-42. [DOI: 10.1002/ddr.21249] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/10/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Min-Seok Park
- Department of Microbiology; College of Natural Science, Pukyong National University; Busan 608-737 Republic of Korea
| | - Nan-Hee Kim
- Department of Microbiology; College of Natural Science, Pukyong National University; Busan 608-737 Republic of Korea
| | - Chang-Won Kang
- Department of Microbiology; College of Natural Science, Pukyong National University; Busan 608-737 Republic of Korea
| | - Chul-Woong Oh
- Department of Marine Biology; College of Fishery Sciences, Pukyong National University; Busan 608-737 Republic of Korea
| | - Gun-Do Kim
- Department of Microbiology; College of Natural Science, Pukyong National University; Busan 608-737 Republic of Korea
| |
Collapse
|
5
|
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.
Collapse
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;
| |
Collapse
|
6
|
Wang QC, Liu J, Wang F, Duan X, Dai XX, Wang T, Liu HL, Cui XS, Sun SC, Kim NH. Role of nucleation-promoting factors in mouse early embryo development. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:559-564. [PMID: 23552571 DOI: 10.1017/s1431927613000032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
During mitosis nucleation-promoting factors (NPFs) bind to the Arp2/3 complex and activate actin assembly. JMY and WAVE2 are two critical members of the NPFs. Previous studies have demonstrated that NPFs promote multiple processes such as cell migration and cytokinesis. However, the role of NPFs in development of mammalian embryos is still unknown. Results of the present study show that the NPFs JMY and WAVE2 are critical for cytokinesis during development of mouse embryos. Both JMY and WAVE2 are expressed in mouse embryos. After injection of JMY or WAVE2 siRNA, all embryos failed to develop to the morula or blastocyst stages. Moreover, using fluorescence intensity analysis, we found that the expression of actin decreased, and multiple nuclei were observed within a single cell indicating that NPFs-induced actin reduction caused the failure of cell division. In addition, injection of JMY and WAVE2 siRNA also caused ARP2 degradation, indicating that involvement of NPFs in development of mouse embryos is mainly through regulation of ARP2/3-induced actin assembly. Taken together, these data suggested that WAVE2 and JMY are involved in development of mouse embryos, and their regulation may be through a NPFs-Arp2/3-actin pathway.
Collapse
Affiliation(s)
- Qiao-Chu Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Suetsugu S. Activation of nucleation promoting factors for directional actin filament elongation: allosteric regulation and multimerization on the membrane. Semin Cell Dev Biol 2013; 24:267-71. [PMID: 23380397 DOI: 10.1016/j.semcdb.2013.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 01/11/2013] [Accepted: 01/17/2013] [Indexed: 01/02/2023]
Abstract
Nucleation promoting factors (NPFs) activate the Arp2/3 complex to produce branched actin filaments. Branched actin filaments are observed in most organelles, and specific NPFs, such as WASP, N-WASP, WAVEs, WASH, and WHAMM, exist for each organelle. Interestingly, Arp2/3 and NPFs are both inactive by themselves, and thus require activation. The exposure of the Arp2/3 activating region, the VCA fragment, is recognized to be a key event in the activation of the NPFs. Together, small GTPase binding, phosphorylation, SH3 binding, and membrane binding promote VCA exposure synergistically. The increase in the local concentration of NPF by multimerization is thought to occur with the combination of such activators, to maximally activate the NPF and confine the region of actin polymerization. The mechanism of uni-directional filament extension beneath the membrane also is discussed.
Collapse
Affiliation(s)
- Shiro Suetsugu
- Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
| |
Collapse
|
8
|
Pathway of actin filament branch formation by Arp2/3 complex revealed by single-molecule imaging. Proc Natl Acad Sci U S A 2013; 110:1285-90. [PMID: 23292935 DOI: 10.1073/pnas.1211164110] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Actin filament nucleation by actin-related protein (Arp) 2/3 complex is a critical process in cell motility and endocytosis, yet key aspects of its mechanism are unknown due to a lack of real-time observations of Arp2/3 complex through the nucleation process. Triggered by the verprolin homology, central, and acidic (VCA) region of proteins in the Wiskott-Aldrich syndrome protein (WASp) family, Arp2/3 complex produces new (daughter) filaments as branches from the sides of preexisting (mother) filaments. We visualized individual fluorescently labeled Arp2/3 complexes dynamically interacting with and producing branches on growing actin filaments in vitro. Branch formation was strikingly inefficient, even in the presence of VCA: only ~1% of filament-bound Arp2/3 complexes yielded a daughter filament. VCA acted at multiple steps, increasing both the association rate of Arp2/3 complexes with mother filament and the fraction of filament-bound complexes that nucleated a daughter. The results lead to a quantitative kinetic mechanism for branched actin assembly, revealing the steps that can be stimulated by additional cellular factors.
Collapse
|
9
|
Liu J, Wang QC, Wang F, Duan X, Dai XX, Wang T, Liu HL, Cui XS, Kim NH, Sun SC. Nucleation promoting factors regulate the expression and localization of Arp2/3 complex during meiosis of mouse oocytes. PLoS One 2012; 7:e52277. [PMID: 23272233 PMCID: PMC3525642 DOI: 10.1371/journal.pone.0052277] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 11/12/2012] [Indexed: 11/18/2022] Open
Abstract
The actin nucleation factor Arp2/3 complex is a main regulator of actin assembly and is involved in multiple processes like cell migration and adhesion, endocytosis, and the establishment of cell polarity in mitosis. Our previous work showed that the Arp2/3 complex was involved in the actin-mediated mammalian oocyte asymmetric division. However, the regulatory mechanisms and signaling pathway of Arp2/3 complex in meiosis is still unclear. In the present work, we identified that the nucleation promoting factors (NPFs) JMY and WAVE2 were necessary for the expression and localization of Arp2/3 complex in mouse oocytes. RNAi of both caused the degradation of actin cap intensity, indicating the roles of NPFs in the formation of actin cap. Moreover, JMY and WAVE2 RNAi decreased the expression of ARP2, a key component of Arp2/3 complex. However, knock down of Arp2/3 complex by Arpc2 and Arpc3 siRNA microinjection did not affect the expression and localization of JMY and WAVE2. Our results indicate that the NPFs, JMY and WAVE2, are upstream regulators of Arp2/3 complex in mammalian oocyte asymmetric division.
Collapse
Affiliation(s)
- Jun Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Qiao-Chu Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Fei Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xing Duan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiao-Xin Dai
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Teng Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Hong-Lin Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiang-Shun Cui
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, Korea
| | - Nam-Hyung Kim
- Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, Korea
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- * E-mail:
| |
Collapse
|
10
|
Samuel F, Hynds DL. RHO GTPase signaling for axon extension: is prenylation important? Mol Neurobiol 2010; 42:133-42. [PMID: 20878268 DOI: 10.1007/s12035-010-8144-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 09/12/2010] [Indexed: 12/27/2022]
Abstract
Many lines of evidence indicate the importance of the Rho family guanine nucleotide triphosphatases (GTPases) in directing axon extension and guidance. The signaling networks that involve these proteins regulate actin cytoskeletal dynamics in navigating neuronal growth cones. However, the intricate patterns that regulate Rho GTPase activation and signaling are not yet fully defined. Activity and subcellular localization of the Rho GTPases are regulated by post-translational modification. The addition of a geranylgeranyl group to the carboxy (C-) terminus targets Rho GTPases to the plasma membrane and promotes their activation by facilitating interaction with guanine nucleotide exchange factors and allowing sequestering by association with guanine dissociation inhibitors. However, it is unclear how these modifications affect neurite extension or how subcellular localization alters signaling from the classical Rho GTPases (RhoA, Rac1, and Cdc42). Here, we review recent data addressing this issue and propose that Rho GTPase geranylgeranylation regulates outgrowth.
Collapse
Affiliation(s)
- Filsy Samuel
- Department of Biology, Texas Woman's University, PO Box 425799, Denton, TX 46204-5799, USA
| | | |
Collapse
|
11
|
The molecular mechanisms of transition between mesenchymal and amoeboid invasiveness in tumor cells. Cell Mol Life Sci 2009; 67:63-71. [PMID: 19707854 PMCID: PMC2801846 DOI: 10.1007/s00018-009-0132-1] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/10/2009] [Accepted: 08/11/2009] [Indexed: 01/02/2023]
Abstract
Tumor cells exhibit at least two distinct modes of migration when invading the 3D environment. A single tumor cell’s invasive strategy follows either mesenchymal or amoeboid patterns. Certain cell types can use both modes of invasiveness and undergo transitions between them. This work outlines the signaling pathways involved in mesenchymal and amoeboid types of tumor cell motility and summarizes the molecular mechanisms that are involved in transitions between them. The focus is on the signaling of the Rho family of small GTPases that regulate the cytoskeleton-dependent processes taking place during the cell migration. The multiple interactions among the Rho family of proteins, their regulators and effectors are thought to be the key determinants of the particular type of invasiveness. Mesenchymal and amoeboid invasive strategies display different adhesive and proteolytical interactions with the surrounding matrix and the alterations influencing these interactions can also lead to the transitions.
Collapse
|
12
|
Gieni RS, Hendzel MJ. Actin dynamics and functions in the interphase nucleus: moving toward an understanding of nuclear polymeric actin. Biochem Cell Biol 2009; 87:283-306. [PMID: 19234542 DOI: 10.1139/o08-133] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Actin exists as a dynamic equilibrium of monomers and polymers within the nucleus of living cells. It is utilized by the cell for many aspects of gene regulation, including mRNA processing, chromatin remodelling, and global gene expression. Polymeric actin is now specifically linked to transcription by RNA polymerase I, II, and III. An active process, requiring both actin polymers and myosin, appears to drive RNA polymerase I transcription, and is also implicated in long-range chromatin movement. This type of mechanism brings activated genes from separate chromosomal territories together, and then participates in their compartmentalization near nuclear speckles. Nuclear speckle formation requires polymeric actin, and factors promoting polymerization, such as profilin and PIP2, are concentrated there. A review of the literature shows that a functional population of G-actin cycles between the cytoplasm and the nucleoplasm. Its nuclear concentration is dependent on the cytoplasmic G-actin pool, as well as on the activity of import and export mechanisms and the availability of interactions that sequester it within the nucleus. The N-WASP-Arp2/3 actin polymer-nucleating mechanism functions in the nucleus, and its mediators, including NCK, PIP2, and Rac1, can be found in the nucleoplasm, where they likely influence the kinetics of polymer formation. The actin polymer species produced are tightly regulated, and may take on conformations not easily recognized by phalloidin. Many of the factors that cleave F-actin in the cytoplasm are present at high levels in the nucleoplasm, and are also likely to affect actin dynamics there. The absolute and relative G-actin content in the nucleoplasm and the cytoplasm of a cell contains information about the homeostatic state of that cell. We propose that the cycling of G-actin between the nucleus and cytoplasm represents a signal transduction mechanism that can function through both extremes of global cellular G-actin content. MAL signalling within the serum response factor pathway, when G-actin levels are low, represents a well-studied example of actin functioning in signal transduction. The translocation of NCK into the nucleus, along with G-actin, during dissolution of the cytoskeleton in response to DNA damage represents another instance of a unique signalling mechanism operating when G-actin levels are high.
Collapse
Affiliation(s)
- Randall S Gieni
- Cross Cancer Institute and Department of Oncology, Faculty of Medicine, University of Alberta, Edmonton, ABT6G1Z2, Canada
| | | |
Collapse
|
13
|
Ammer AG, Weed SA. Cortactin branches out: roles in regulating protrusive actin dynamics. ACTA ACUST UNITED AC 2008; 65:687-707. [PMID: 18615630 DOI: 10.1002/cm.20296] [Citation(s) in RCA: 210] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Since its discovery in the early 1990's, cortactin has emerged as a key signaling protein in many cellular processes, including cell adhesion, migration, endocytosis, and tumor invasion. While the list of cellular functions influenced by cortactin grows, the ability of cortactin to interact with and alter the cortical actin network is central to its role in regulating these processes. Recently, several advances have been made in our understanding of the interaction between actin and cortactin, providing insight into how these two proteins work together to provide a framework for normal and altered cellular function. This review examines how regulation of cortactin through post-translational modifications and interactions with multiple binding partners elicits changes in cortical actin cytoskeletal organization, impacting the regulation and formation of actin-rich motility structures.
Collapse
Affiliation(s)
- Amanda Gatesman Ammer
- Department of Neuroscience and Anatomy, Program in Cancer Cell Biology, Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, West Virginia 26506-9300, USA
| | | |
Collapse
|
14
|
Sarmiento C, Wang W, Dovas A, Yamaguchi H, Sidani M, El-Sibai M, Desmarais V, Holman HA, Kitchen S, Backer JM, Alberts A, Condeelis J. WASP family members and formin proteins coordinate regulation of cell protrusions in carcinoma cells. ACTA ACUST UNITED AC 2008; 180:1245-60. [PMID: 18362183 PMCID: PMC2290849 DOI: 10.1083/jcb.200708123] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We examined the role of the actin nucleation promoters neural Wiskott-Aldrich syndrome protein (N-WASP) and WAVE2 in cell protrusion in response to epidermal growth factor (EGF), a key regulator in carcinoma cell invasion. We found that WAVE2 knockdown (KD) suppresses lamellipod formation and increases filopod formation, whereas N-WASP KD has no effect. However, simultaneous KD of both proteins results in the formation of large jagged protrusions with lamellar properties and increased filopod formation. This suggests that another actin nucleation activity is at work in carcinoma cells in response to EGF. A mammalian Diaphanous–related formin, mDia1, localizes at the jagged protrusions in double KD cells. Constitutively active mDia1 recapitulated the phenotype, whereas inhibition of mDia1 blocked the formation of these protrusions. Increased RhoA activity, which stimulates mDia1 nucleation, was observed in the N-WASP/WAVE2 KD cells and was shown to be required for the N-WASP/WAVE2 KD phenotype. These data show that coordinate regulation between the WASP family and mDia proteins controls the balance between lamellar and lamellipodial protrusion activity.
Collapse
Affiliation(s)
- Corina Sarmiento
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Kim DJ, Kim SH, Kim SM, Bae JI, Ahnn J, Song WK. F-actin binding region of SPIN90 C-terminus is essential for actin polymerization and lamellipodia formation. ACTA ACUST UNITED AC 2007; 14:33-43. [PMID: 17453829 DOI: 10.1080/15419060701225010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We recently reported that SPIN90 is able to bind with several proteins involved in regulating actin cytoskeleton networks, including dynamin, WASP, beta PIX, and Nck. Based on these findings, we investigated how SPIN90 regulates the actin cytoskeleton and promotes actin assembly. This study demonstrated that aluminium fluoride-induced localization of SPIN90 to lamellipodia requires amino acids 582-722 at the SPIN90 C-terminus, which is also essential for F-actin binding and Arp2/3 complex mediated polymerization of actin into branched actin filaments. Furthermore, after deletion of the F-actin binding region (582-722 SPIN90) failed to localize at the membrane edge and was unable to promote lamellipodia formation, suggesting that the F-actin binding region in the SPIN90 C-terminus is essential for the formation of branched actin networks and regulation of the actin cytoskeleton at the leading edge of cells.
Collapse
Affiliation(s)
- Dae Joong Kim
- Department of Life Science and Center for Distributed Sensor Network, Gwangju Institute of Science and Technology, Gwangju, Korea
| | | | | | | | | | | |
Collapse
|
16
|
Takenawa T, Suetsugu S. The WASP-WAVE protein network: connecting the membrane to the cytoskeleton. Nat Rev Mol Cell Biol 2007; 8:37-48. [PMID: 17183359 DOI: 10.1038/nrm2069] [Citation(s) in RCA: 698] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Wiskott-Aldrich syndrome protein (WASP) and WASP-family verprolin-homologous protein (WAVE) family proteins are scaffolds that link upstream signals to the activation of the ARP2/3 complex, leading to a burst of actin polymerization. ARP2/3-complex-mediated actin polymerization is crucial for the reorganization of the actin cytoskeleton at the cell cortex for processes such as cell movement, vesicular trafficking and pathogen infection. Large families of membrane-binding proteins were recently found to interact with WASP and WAVE family proteins, therefore providing a new layer of membrane-dependent regulation of actin polymerization.
Collapse
Affiliation(s)
- Tadaomi Takenawa
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokane-dai, Minato-ku, Tokyo 108-8639, Japan.
| | | |
Collapse
|
17
|
Shakir MA, Gill JS, Lundquist EA. Interactions of UNC-34 Enabled with Rac GTPases and the NIK kinase MIG-15 in Caenorhabditis elegans axon pathfinding and neuronal migration. Genetics 2006; 172:893-913. [PMID: 16204220 PMCID: PMC1456253 DOI: 10.1534/genetics.105.046359] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Accepted: 09/21/2005] [Indexed: 01/20/2023] Open
Abstract
Many genes that affect axon pathfinding and cell migration have been identified. Mechanisms by which these genes and the molecules they encode interact with one another in pathways and networks to control developmental events are unclear. Rac GTPases, the cytoskeletal signaling molecule Enabled, and NIK kinase have all been implicated in regulating axon pathfinding and cell migration. Here we present evidence that, in Caenorhabditis elegans, three Rac GTPases, CED-10, RAC-2, and MIG-2, define three redundant pathways that each control axon pathfinding, and that the NIK kinase MIG-15 acts in each Rac pathway. Furthermore, we show that the Enabled molecule UNC-34 defines a fourth partially redundant pathway that acts in parallel to Rac/MIG-15 signaling in axon pathfinding. Enabled and the three Racs also act redundantly to mediate AQR and PQR neuronal cell migration. The Racs and UNC-34 Ena might all control the formation of actin-based protrusive structures (lamellipodia and filopodia) that mediate growth cone outgrowth and cell migration. MIG-15 does not act with the three Racs in execution of cell migration. Rather, MIG-15 affects direction of PQR neuronal migration, similar to UNC-40 and DPY-19, which control initial Q cell polarity, and Wnt signaling, which acts later to control Q cell-directed migration. MIG-2 Rac, which acts with CED-10 Rac, RAC-2 Rac, and UNC-34 Ena in axon pathfinding and cell migration, also acts with MIG-15 in PQR directional migration.
Collapse
Affiliation(s)
- M Afaq Shakir
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
| | | | | |
Collapse
|
18
|
Abstract
The actin-nucleating Arp2/3 complex is essential for life in yeast and animals, but not in plants, in which mutants of Arp2/3 complex components show relatively minor developmental abnormalities. Animal cells control the activity of the Arp2/3 complex through the suppressor of cyclic AMP receptor (SCAR) complex to achieve cell motility. Amazingly, plants have also retained the SCAR cell-motility pathway, and now provide a unique model for the study of new aspects of SCAR function in the absence of cell motility.
Collapse
Affiliation(s)
- Michael J Deeks
- The Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, University of Durham, South Road, Durham, DH1 3LE, UK
| | | |
Collapse
|
19
|
Pilpel Y, Segal M. Rapid WAVE dynamics in dendritic spines of cultured hippocampal neurons is mediated by actin polymerization. J Neurochem 2005; 95:1401-10. [PMID: 16190876 DOI: 10.1111/j.1471-4159.2005.03467.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Wiskott-Aldrich syndrome protein family Verprolin-homologous protein (WAVE) complex has been proposed to link Rho GTPase activity with actin polymerization but its role in neuronal plasticity has never been documented. We now examined the presence, distribution and dynamics of WAVE3 in cultured hippocampal neurons. WAVE3 was localized to dendritic spines via its N-terminal domain. Green fluorescent protein (GFP)-tagged WAVE3 clusters demonstrate an F-actin-dependent high rate of local motility. Constitutive Rac activation translocates WAVE3 (via the N-terminus), to the leading edge of lamellipodia. Also, spinogenesis is associated with actin-based motility of the WAVE3 protein. Brain specific WAVE1 showed similar localization and effects on spine density. Cytoplasmic fragile X mental retardation protein interacting protein (CYFIP) and non-catalytic region of tyrosine kinase adaptor protein 1 (NCK-1), proteins that are assumed to complex with WAVE, have a somewhat similar cellular distribution and motility. We propose that the WAVE complex is a downstream effector of the Rac signaling cascade, localized to sites of novel synaptic contacts by means of its N-terminal domain, to guide local actin polymerization needed for morphological plasticity of neurons.
Collapse
Affiliation(s)
- Yair Pilpel
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
| | | |
Collapse
|
20
|
Suzuki K, Chikamatsu Y, Takahashi K. Requirement of protein phosphatase 2A for recruitment of IQGAP1 to Rac-bound beta1 integrin. J Cell Physiol 2005; 203:487-92. [PMID: 15521075 DOI: 10.1002/jcp.20249] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Serine/threonine protein phosphatase (PP) 2A is thought to dephosphorylate phosphorylated beta1 integrin to link with actin filaments (F-actin). However, whether PP2A participates in the regulation of F-actin assembly to which beta1 integrin is anchored is unclear. We report here that the core enzyme of PP2A (PP2A-AC), consisting of the regulatory subunit A (PP2A-A) and the catalytic subunit C (PP2A-C), forms a complex with beta1 integrin, a small GTPase Rac, and its effector IQGAP1 in non-malignant human mammary epithelial (HME) cells. Treatment of HME cells with okadaic acid (OA), an inhibitor of PP2A, caused cell rounding, reduction in F-actin assembly that links with beta1 integrin, and dissociation of IQGAP1-bound PP2A-AC from Rac-beta1 integrin. The dissociation of IQGAP1-PP2A-AC was accompanied by loss of F-actin gelating activity of Rac-beta1 integrin. In breast cancer MCF-7 cells, which possess PP2A-C but lack PP2A-A, IQGAP1 was not associated with Rac-beta1 integrin but with PP2A-C, with no distinct F-actin assembly that linked to Rac-beta1 integrin even before treatment with OA. We therefore propose that PP2A, especially PP2A-A, functions to maintain F-actin assembly to which beta1 integrin is anchored by recruitment of IQGAP1 to Rac-beta1 integrin.
Collapse
Affiliation(s)
- Katsuo Suzuki
- Department of Biochemistry, Kanagawa Cancer Center Research Institute, Yokohama, Japan
| | | | | |
Collapse
|
21
|
Park SJ, Suetsugu S, Takenawa T. Interaction of HSP90 to N-WASP leads to activation and protection from proteasome-dependent degradation. EMBO J 2005; 24:1557-70. [PMID: 15791211 PMCID: PMC1142563 DOI: 10.1038/sj.emboj.7600586] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Accepted: 01/26/2005] [Indexed: 11/09/2022] Open
Abstract
Neural Wiskott-Aldrich syndrome protein (N-WASP) regulates reorganization of the actin cytoskeleton through activation of the Arp2/3 complex. Here, we show that heat shock protein 90 (HSP90) regulates N-WASP-induced actin polymerization in cooperation with phosphorylation of N-WASP. HSP90 binds directly to N-WASP, but binding alone does not affect the rate of N-WASP/Arp2/3 complex-induced in vitro actin polymerization. An Src family tyrosine kinase, v-Src, phosphorylates and activates N-WASP. HSP90 increases the phosphorylation of N-WASP by v-Src, leading to enhanced N-WASP-dependent actin polymerization. In addition, HSP90 protects phosphorylated and activated N-WASP from proteasome-dependent degradation, resulting in amplification of N-WASP-dependent actin polymerization. Association between HSP90 and N-WASP is increased in proportion to activation of N-WASP by phosphorylation. HSP90 is colocalized and associated with active N-WASP at podosomes in 3Y1/v-Src cells and at growing neurites in PC12 cells, whose actin structures are clearly inhibited by blocking the binding of HSP90 to N-WASP. These findings suggest that HSP90 induces efficient activation of N-WASP downstream of phosphorylation signal by Src family kinases and is critical for N-WASP-dependent podosome formation and neurite extension.
Collapse
Affiliation(s)
- Sun Joo Park
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- CREST, Japan Science and Technology Corporation (JST), Shirokanedai, Minato-ku, Tokyo, Japan
| | - Shiro Suetsugu
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- CREST, Japan Science and Technology Corporation (JST), Shirokanedai, Minato-ku, Tokyo, Japan
| | - Tadaomi Takenawa
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- CREST, Japan Science and Technology Corporation (JST), Shirokanedai, Minato-ku, Tokyo, Japan
- Department of Biochemistry, Institute of Medical Sciences, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. Tel.: +81 3 5449 5510; Fax: +81 3 5449 5417; E-mail:
| |
Collapse
|
22
|
Kato M, Takenawa T. WICH, a member of WASP-interacting protein family, cross-links actin filaments. Biochem Biophys Res Commun 2005; 328:1058-66. [PMID: 15707985 DOI: 10.1016/j.bbrc.2005.01.058] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2004] [Indexed: 10/25/2022]
Abstract
In yeast, Verprolin plays an important role in rearrangement of the actin cytoskeleton. There are three mammalian homologues of Verprolin, WIP, CR16, and WICH, and all of them bind actin and Wiskott-Aldrich syndrome protein (WASP) and/or neural-WASP. Here, we describe a novel function of WICH. In vitro co-sedimentation analysis revealed that WICH not only binds to actin filaments but also cross-links them. Fluorescence and electron microscopy detected that this cross-linking results in straight bundled actin filaments. Overexpression of WICH alone in cultured fibroblast caused the formation of thick actin fibers. This ability of WICH depended on its own actin cross-linking activity. Importantly, the actin cross-linking activity of WICH was modified through a direct association with N-WASP. Taken together, these data suggest that WICH induces a bundled form of actin filament with actin cross-linking activity and the association with N-WASP suppresses that activity. WICH thus appears to be a novel actin bundling protein.
Collapse
Affiliation(s)
- Masayoshi Kato
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Mianato-ku, Tokyo 108-8639, Japan
| | | |
Collapse
|
23
|
Nakajima E, Suzuki K, Takahashi K. Mitotic dissociation of IQGAP1 from Rac-bound beta1-integrin is mediated by protein phosphatase 2A. Biochem Biophys Res Commun 2005; 326:249-53. [PMID: 15567178 DOI: 10.1016/j.bbrc.2004.11.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Indexed: 11/19/2022]
Abstract
Assembly of F-actin that links with beta1-integrin during the G1 phase of cell cycle is released from beta1-integrin and disrupted at mitosis. However, it remains unclear how F-actin assembly to which beta1-integrin anchors is cell cycle-dependently regulated. We show that beta1-integrin was co-immunoprecipitated and co-localized with a small GTPase Rac and its effector IQGAP1, along with PP2A-AC, in HME cells during G1. When the cells were accumulated to G2/M, the co-immunoprecipitation or co-localization of IQGAP1 and PP2A-AC with beta1-integrin was lost, leaving Rac bound to beta1-integrin. The dissociated IQGAP1 was co-immunoprecipitated with the concomitantly dissociated PP2A-A and -C, indicating the complex formation among the proteins in G2/M cells. Falling ball viscometric assays revealed that only IQGAP1-bound beta1-integrin-Rac in G1 cells exhibited an enhanced F-actin cross-linking activity. The results suggest that the mitotic loss of F-actin assembly to which beta1-integrin anchors is due to PP2A-mediated dissociation of IQGAP1 from Rac-bound beta1-integrin.
Collapse
Affiliation(s)
- Eri Nakajima
- Department of Biochemistry, Kanagawa Cancer Center Research Institute, 1-1-2 Nakao, Asahi-ku, Yokohama 241-0815, Japan
| | | | | |
Collapse
|
24
|
Rodal AA, Sokolova O, Robins DB, Daugherty KM, Hippenmeyer S, Riezman H, Grigorieff N, Goode BL. Conformational changes in the Arp2/3 complex leading to actin nucleation. Nat Struct Mol Biol 2004; 12:26-31. [PMID: 15592479 DOI: 10.1038/nsmb870] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Accepted: 10/22/2004] [Indexed: 11/08/2022]
Abstract
The two actin-related subunits of the Arp2/3 complex, Arp2 and Arp3, are proposed to form a pseudo actin dimer that nucleates actin polymerization. However, in the crystal structure of the inactive complex, they are too far apart to form such a nucleus. Here, we show using EM that yeast and bovine Arp2/3 complexes exist in a distribution among open, intermediate and closed conformations. The crystal structure docks well into the open conformation. The activator WASp binds at the cleft between Arp2 and Arp3, and all WASp-bound complexes are closed. The inhibitor coronin binds near the p35 subunit, and all coronin-bound complexes are open. Activating and loss-of-function mutations in the p35 subunit skew conformational distribution in opposite directions, closed and open, respectively. We conclude that WASp stabilizes p35-dependent closure of the complex, holding Arp2 and Arp3 closer together to nucleate an actin filament.
Collapse
Affiliation(s)
- Avital A Rodal
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Stradal TEB, Rottner K, Disanza A, Confalonieri S, Innocenti M, Scita G. Regulation of actin dynamics by WASP and WAVE family proteins. Trends Cell Biol 2004; 14:303-11. [PMID: 15183187 DOI: 10.1016/j.tcb.2004.04.007] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Theresia E B Stradal
- German Research Centre for Biotechnology, Department of Cell Biology, Mascheroder Weg 1, D-38124 Braunschweig, Germany
| | | | | | | | | | | |
Collapse
|
26
|
Suetsugu S, Takenawa T. Translocation of N-WASP by nuclear localization and export signals into the nucleus modulates expression of HSP90. J Biol Chem 2003; 278:42515-23. [PMID: 12871950 DOI: 10.1074/jbc.m302177200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-WASP regulates the actin cytoskeleton through activation of the Arp2/3 complex. N-WASP localizes at the cell periphery, where it controls actin polymerization downstream of signal molecules such as adapter proteins, Cdc42, Src family kinases, and phosphoinositides. N-WASP also localizes in the nucleus; however, the role of N-WASP in the nucleus is unclear. Here, we show that localization of N-WASP is controlled through phosphorylation by Src family kinases in which phosphorylated N-WASP is exported from the nucleus in a nuclear export signal (NES) and leptomycin B-dependent manner. N-WASP had nuclear localization signal (NLS) at its basic region and NES close to the phosphorylation site by Src family kinases, indicating that phosphorylation controls the accessibility to the NES through conformational changes. Increased levels of unphosphorylated N-WASP in the nucleus suppressed expression of HSP90 and transcription from a heat shock element (HSE). N-WASP bound heat shock transcription factor (HSTF) and enhanced the HSTF association with HSE. In addition, nuclear N-WASP was present in the protein complex that associates with HSE, suggesting that N-WASP participates in suppression of HSP90 transcription. Increased levels of unphosphorylated N-WASP also decreased the activities of Src family kinases in cells but not in experiments in vitro with pure N-WASP and Fyn. Because HSP90 is essential for the activities of Src family kinases, these results suggest that localization of N-WASP modulates Src kinase activity by regulating HSP90 expression.
Collapse
Affiliation(s)
- Shiro Suetsugu
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Japan
| | | |
Collapse
|
27
|
Head JA, Jiang D, Li M, Zorn LJ, Schaefer EM, Parsons JT, Weed SA. Cortactin tyrosine phosphorylation requires Rac1 activity and association with the cortical actin cytoskeleton. Mol Biol Cell 2003; 14:3216-29. [PMID: 12925758 PMCID: PMC181562 DOI: 10.1091/mbc.e02-11-0753] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cortactin is an F-actin binding protein that activates actin-related protein 2/3 complex and is localized within lamellipodia. Cortactin is a substrate for Src and other protein tyrosine kinases involved in cell motility, where its phosphorylation on tyrosines 421, 466, and 482 in the carboxy terminus is required for cell movement and metastasis. In spite of the importance of cortactin tyrosine phosphorylation in cell motility, little is known regarding the structural, spatial, or signaling requirements regulating cortactin tyrosine phosphorylation. Herein, we report that phosphorylation of cortactin tyrosine residues in the carboxy terminus requires the aminoterminal domain and Rac1-mediated localization to the cell periphery. Phosphorylation-specific antibodies directed against tyrosine 421 and 466 were produced to study the regulation and localization of tyrosine phosphorylated cortactin. Phosphorylation of cortactin tyrosine 421 and 466 was elevated in response to Src, epidermal growth factor receptor and Rac1 activation, and tyrosine 421 phosphorylated cortactin localized with F-actin in lamellipodia and podosomes. Cortactin tyrosine phosphorylation is progressive, with tyrosine 421 phosphorylation required for phosphorylation of tyrosine 466. These results indicate that cortactin tyrosine phosphorylation requires Rac1-induced cortactin targeting to cortical actin networks, where it is tyrosine phosphorylated in hierarchical manner that is closely coordinated with its ability to regulate actin dynamics.
Collapse
Affiliation(s)
- Julie A Head
- Department of Craniofacial Biology and Cancer Center, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
| | | | | | | | | | | | | |
Collapse
|
28
|
Eckley DM, Schroer TA. Interactions between the evolutionarily conserved, actin-related protein, Arp11, actin, and Arp1. Mol Biol Cell 2003; 14:2645-54. [PMID: 12857853 PMCID: PMC165665 DOI: 10.1091/mbc.e03-01-0049] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The dynein activator dynactin is a multiprotein complex with distinct microtubule- and cargo-binding domains. The cargo-binding domain contains a short, actin-like filament of the actin-related protein Arp1, a second actin-related protein, Arp11, and conventional actin. The length of this filament is invariant in dynactin isolated from multiple species and tissues, suggesting that activities that regulate Arp1 polymerization are important for dynactin assembly. Arp11 is present in a protein complex localized at the pointed end of the Arp1 minifilament, whereas actin capping protein (CapZ) is present at the barbed end. Either might cooperate with conventional actin to cap Arp1. We tested the ability of Arp11 to interact with conventional actin and found it could coassemble. Like Arp1, cytosolic Arp11 is found only in dynactin, suggesting that Arp11 and free cytosolic actin do not interact significantly. Recombinant Arp11 and Arp1 were demonstrated to interact by coprecipitation. We developed an in vivo assay for Arp11-Arp1 interaction based on previous observations that Arp1 forms filamentous assemblies when overexpressed in cultured cells. Arp11 significantly decreases the formation of these organized Arp1 assemblies. Finally, this assay was used to confirm the identity of a putative Arp11 homolog in Drosophila melanogaster.
Collapse
Affiliation(s)
- D Mark Eckley
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | |
Collapse
|
29
|
Cory GOC, Cramer R, Blanchoin L, Ridley AJ. Phosphorylation of the WASP-VCA domain increases its affinity for the Arp2/3 complex and enhances actin polymerization by WASP. Mol Cell 2003; 11:1229-39. [PMID: 12769847 DOI: 10.1016/s1097-2765(03)00172-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Wiskott-Aldrich syndrome protein (WASP) and neural (N)-WASP regulate dynamic actin structures through the ability of their VCA domains to bind to and stimulate the actin nucleating activity of the Arp2/3 complex. Here we identify two phosphorylation sites in the VCA domain of WASP at serines 483 and 484. S483 and S484 are substrates for casein kinase 2 in vitro and in vivo. Phosphorylation of these residues increases the affinity of the VCA domain for the Arp2/3 complex 7-fold and is required for efficient in vitro actin polymerization by the full-length WASP molecule. We propose that constitutive VCA domain phosphorylation is required for optimal stimulation of the Arp2/3 complex by WASP.
Collapse
Affiliation(s)
- Giles O C Cory
- Ludwig Institute for Cancer Research, Royal Free and University College Medical School Branch, Courtauld Building, 91 Riding House Street, London W1W 7BS, United Kingdom
| | | | | | | |
Collapse
|
30
|
Sawa M, Suetsugu S, Sugimoto A, Miki H, Yamamoto M, Takenawa T. Essential role of the C. elegans Arp2/3 complex in cell migration during ventral enclosure. J Cell Sci 2003; 116:1505-18. [PMID: 12640035 DOI: 10.1242/jcs.00362] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Migration of cells through the reorganization of the actin cytoskeleton is essential for morphogenesis of multicellular animals. In a cell culture system, the actin-related protein (Arp) 2/3 complex functions as a nucleation core for actin polymerization when activated by the members of the WASP (Wiskott-Aldrich syndrome protein) family. However, the regulation of cell motility in vivo remains poorly understood. Here we report that homologues of the mammalian Arp2/3 complex and N-WASP in Caenorhabditis elegans play an important role in hypodermal cell migration during morphogenesis, a process known as ventral enclosure. In the absence of one of any of the C. elegans Arp2/3 complex subunits (ARX-1, ARX-2, ARX-4, ARX-5, ARX-6 or ARX-7) or of N-WASP (WSP-1), hypodermal cell migration led by actin-rich filopodia formation is inhibited during ventral enclosure owing to the reduction of filamentous actin formation. However, there is no effect on differentiation of hypodermal cells and dorsal intercalation. Disruption of the function of ARX-1 and WSP-1 in hypodermal cells also resulted in hypodermal cell arrest during ventral enclosure, suggesting that their function is cell autonomous. WSP-1 protein activated Arp2/3-mediated actin polymerization in vitro. Consistent with these results, the Arp2/3 complex and WSP-1 colocalized at the leading edge of migrating hypodermal cells. The stable localization of WSP-1 was dependent on the presence of Arp2/3 complex, suggesting an interaction between the Arp2/3 complex and WSP-1 in vivo.
Collapse
Affiliation(s)
- Mariko Sawa
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | | | | | | | | | | |
Collapse
|
31
|
Suetsugu S, Takenawa T. Regulation of Cortical Actin Networks in Cell Migration. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 229:245-86. [PMID: 14669958 DOI: 10.1016/s0074-7696(03)29006-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The actin cytoskeleton is a primary determinant of cell shape and motility. Studies on actin regulatory proteins are now coupled with studies of the signal transduction that directs actin cytoskeleton reorganization, and we have gained insights into how external stimuli such as chemoattractants drive changes in actin cytoskeleton. Chemoattractants regulate actin regulatory proteins such as the Arp2/3 complex through WASP family proteins, ADF/cofilin downstream of LIM-kinase, and various other phosphoinositide-dependent or -independent pathways. Through branching of actin filaments, Arp2/3 complex-dependent actin polymerization is suffcient to generate the force necessary for protrusion.
Collapse
Affiliation(s)
- Shiro Suetsugu
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, and CREST, Japan Science and Technology Corporation, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | | |
Collapse
|
32
|
Fujiwara I, Suetsugu S, Uemura S, Takenawa T, Ishiwata S. Visualization and force measurement of branching by Arp2/3 complex and N-WASP in actin filament. Biochem Biophys Res Commun 2002; 293:1550-5. [PMID: 12054693 DOI: 10.1016/s0006-291x(02)00421-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To determine whether the Arp2/3 complex activated by N-WASP (VCA) branches actin filaments at the side (side branching), or at the barbed (B-)end (end branching) of the mother filaments, we have directly observed the branching process of actin filaments and examined single-molecule unbinding under optical microscope. We found that side branching was predominant, though not exclusive. At the initial stage of polymerization, the branching at the B-end occurred and subsequently the side branching started to occur. In either type of branching, the mother and daughter filaments elongated at nearly the same rate (growing type). Independently of the stage of polymerization, branching due to the direct coupling of filaments with an acute angle to the mother filaments (a coupling type) occurred. Phalloidin suppressed the growing type of branching but not the coupling type, implying that actin monomers are required for the former but not the latter. We found, by single molecule measurements using optical tweezers, that the Arp2/3 complex attaches to the side of actin filaments and the N-WASP appears to detach from the actin-Arp2/3 complex at 6-7 pN.
Collapse
Affiliation(s)
- Ikuko Fujiwara
- Department of Physics, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | | | | | | | | |
Collapse
|
33
|
Suetsugu S, Miki H, Takenawa T. Spatial and temporal regulation of actin polymerization for cytoskeleton formation through Arp2/3 complex and WASP/WAVE proteins. CELL MOTILITY AND THE CYTOSKELETON 2002; 51:113-22. [PMID: 11921168 DOI: 10.1002/cm.10020] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shiro Suetsugu
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | | | | |
Collapse
|