1
|
Differential functions of WAVE regulatory complex subunits in the regulation of actin-driven processes. Eur J Cell Biol 2017; 96:715-727. [PMID: 28889942 DOI: 10.1016/j.ejcb.2017.08.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/23/2017] [Accepted: 08/25/2017] [Indexed: 11/22/2022] Open
Abstract
The WAVE regulatory complex (WRC) links upstream Rho-family GTPase signaling to the activation of the ARP2/3 complex in different organisms. WRC-induced and ARP2/3 complex-mediated actin nucleation beneath the plasma membrane is critical for actin assembly in the leading edge to drive efficient cell migration. The WRC is a stable heteropentamer composed of SCAR/WAVE, Abi, Nap, Pir and the small polypeptide Brk1/Hspc300. Functional interference with individual subunits of the complex frequently results in diminished amounts of the remaining polypeptides of the WRC complex, implying the complex to act as molecular entity. However, Abi was also found to associate with mammalian N-WASP, formins, Eps8/SOS1 or VASP, indicating additional functions of individual WRC subunits in eukaryotic cells. To address this issue systematically, we inactivated all WRC subunits, either alone or in combination with VASP in Dictyostelium cells and quantified the protein content of the remaining subunits in respective WRC knockouts. The individual mutants displayed highly differential phenotypes concerning various parameters, including cell morphology, motility, cytokinesis or multicellular development, corroborating the view of additional roles for individual subunits, beyond their established function in WRC-mediated Arp2/3 complex activation. Finally, our data uncover the interaction of the actin polymerase VASP with WRC-embedded Abi to mediate VASP accumulation in cell protrusions, driving efficient cell migration.
Collapse
|
2
|
Havrylenko S, Noguera P, Abou-Ghali M, Manzi J, Faqir F, Lamora A, Guérin C, Blanchoin L, Plastino J. WAVE binds Ena/VASP for enhanced Arp2/3 complex-based actin assembly. Mol Biol Cell 2014; 26:55-65. [PMID: 25355952 PMCID: PMC4279229 DOI: 10.1091/mbc.e14-07-1200] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A dual in vitro/in vivo approach is used to show that WAVE directly binds Ena/VASP, coordinating its activity with that of the Arp2/3 complex for enhanced actin assembly. The WAVE complex is the main activator of the Arp2/3 complex for actin filament nucleation and assembly in the lamellipodia of moving cells. Other important players in lamellipodial protrusion are Ena/VASP proteins, which enhance actin filament elongation. Here we examine the molecular coordination between the nucleating activity of the Arp2/3 complex and the elongating activity of Ena/VASP proteins for the formation of actin networks. Using an in vitro bead motility assay, we show that WAVE directly binds VASP, resulting in an increase in Arp2/3 complex–based actin assembly. We show that this interaction is important in vivo as well, for the formation of lamellipodia during the ventral enclosure event of Caenorhabditis elegans embryogenesis. Ena/VASP's ability to bind F-actin and profilin-complexed G-actin are important for its effect, whereas Ena/VASP tetramerization is not necessary. Our data are consistent with the idea that binding of Ena/VASP to WAVE potentiates Arp2/3 complex activity and lamellipodial actin assembly.
Collapse
Affiliation(s)
- Svitlana Havrylenko
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - Philippe Noguera
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - Majdouline Abou-Ghali
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - John Manzi
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - Fahima Faqir
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - Audrey Lamora
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| | - Christophe Guérin
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherches en Technologies et Sciences pour le Vivant, CNRS/CEA/INRA/UJF, Grenoble 38054, France
| | - Laurent Blanchoin
- Laboratoire de Physiologie Cellulaire et Végétale, Institut de Recherches en Technologies et Sciences pour le Vivant, CNRS/CEA/INRA/UJF, Grenoble 38054, France
| | - Julie Plastino
- Institut Curie, Centre de Recherche Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168 Université Pierre et Marie Curie, Paris F-75248, France
| |
Collapse
|
3
|
Chen XJ, Squarr AJ, Stephan R, Chen B, Higgins TE, Barry DJ, Martin MC, Rosen MK, Bogdan S, Way M. Ena/VASP proteins cooperate with the WAVE complex to regulate the actin cytoskeleton. Dev Cell 2014; 30:569-84. [PMID: 25203209 PMCID: PMC4165403 DOI: 10.1016/j.devcel.2014.08.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 07/21/2014] [Accepted: 08/01/2014] [Indexed: 01/25/2023]
Abstract
Ena/VASP proteins and the WAVE regulatory complex (WRC) regulate cell motility by virtue of their ability to independently promote actin polymerization. We demonstrate that Ena/VASP and the WRC control actin polymerization in a cooperative manner through the interaction of the Ena/VASP EVH1 domain with an extended proline rich motif in Abi. This interaction increases cell migration and enables VASP to cooperatively enhance WRC stimulation of Arp2/3 complex-mediated actin assembly in vitro in the presence of Rac. Loss of this interaction in Drosophila macrophages results in defects in lamellipodia formation, cell spreading, and redistribution of Ena to the tips of filopodia-like extensions. Rescue experiments of abi mutants also reveals a physiological requirement for the Abi:Ena interaction in photoreceptor axon targeting and oogenesis. Our data demonstrate that the activities of Ena/VASP and the WRC are intimately linked to ensure optimal control of actin polymerization during cell migration and development.
Collapse
Affiliation(s)
- Xing Judy Chen
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Anna Julia Squarr
- Institute of Neurobiology, University of Muenster, Badestrasse 9, 48149 Muenster, Germany
| | - Raiko Stephan
- Institute of Neurobiology, University of Muenster, Badestrasse 9, 48149 Muenster, Germany
| | - Baoyu Chen
- Howard Hughes Medical Institute and Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Theresa E Higgins
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - David J Barry
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Morag C Martin
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Michael K Rosen
- Howard Hughes Medical Institute and Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sven Bogdan
- Institute of Neurobiology, University of Muenster, Badestrasse 9, 48149 Muenster, Germany.
| | - Michael Way
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
| |
Collapse
|
4
|
Yip C, García A. Exploring the potential of platelet proteomics in children. Proteomics Clin Appl 2014; 8:807-12. [PMID: 25090967 DOI: 10.1002/prca.201400048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/04/2014] [Accepted: 07/31/2014] [Indexed: 01/04/2023]
Abstract
Proteomics is a rapidly evolving ''post-genomic'' science utilizing advanced technologies in protein separation, identification, quantitation and heavily relying on bioinformatics. Proteomic research in pediatrics is important and most of the successes thus far are seen in research that utilize samples that require less invasive procedures and focus on prevailing childhood diseases such as acute lymphoblastic leukaemia and neuroblastoma. Recent advances in proteomics are helping to elucidate platelet processes that are relevant to bleeding and clotting disorders, as well as other important roles of platelets such as in angiogenesis and inflammation. Nevertheless, most of platelet proteome data obtained to date are derived from the adult population and the potential of platelet proteomic application in children has not yet been explored. As it happens in all research fields, there are additional challenges in studying children such as procuring sufficient biological samples and access to less common disease cohorts as compared to in adults. Furthermore, many of the prevalent platelet-mediated diseases in adults, such as coronary heart disease and atherosclerotic lesions, are believed to have origins during childhood. Hence, platelet proteomic research in children may reveal some important information on how platelet plays a role in the pathogenesis of disease. In this article, we refer to the current knowledge from platelet proteomic research strategies in adults and address the specific concerns in the study of pediatric samples.
Collapse
Affiliation(s)
- Christina Yip
- Department of Laboratory Medicine, Division of Haematology, National University Hospital, Singapore
| | | |
Collapse
|
5
|
Systems biology of platelet-vessel wall interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 844:85-98. [PMID: 25480638 DOI: 10.1007/978-1-4939-2095-2_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Platelets are small, anucleated cells that participate in primary hemostasis by forming a hemostatic plug at the site of a blood vessel's breach, preventing blood loss. However, hemostatic events can lead to excessive thrombosis, resulting in life-threatening strokes, emboli, or infarction. Development of multi-scale models coupling processes at several scales and running predictive model simulations on powerful computer clusters can help interdisciplinary groups of researchers to suggest and test new patient-specific treatment strategies.
Collapse
|
6
|
Abl-1-bridged tyrosine phosphorylation of VASP by Abelson kinase impairs association of VASP to focal adhesions and regulates leukaemic cell adhesion. Biochem J 2012; 441:889-99. [PMID: 22014333 DOI: 10.1042/bj20110951] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Mena [mammalian Ena (Enabled)]/VASP (vasodilator-stimulated phosphoprotein) proteins are the homologues of Drosophila Ena. In Drosophila, Ena is a substrate of the tyrosine kinase DAbl (Drosophila Abl). However, the link between Abl and the Mena/VASP family is not fully understood in mammals. We previously reported that Abi-1 (Abl interactor 1) promotes phosphorylation of Mena and BCAP (B-cell adaptor for phosphoinositide 3-kinase) by bridging the interaction between c-Abl and the substrate. In the present study we have identified VASP, another member of the Mena/VASP family, as an Abi-1-bridged substrate of Abl. VASP is phosphorylated by Abl when Abi-1 is co-expressed. We also found that VASP interacted with Abi-1 both in vitro and in vivo. VASP was tyrosine-phosphorylated in Bcr-Abl-positive leukaemic cells in an Abi-1-dependent manner. Co-expression of c-Abl and Abi-1 or the phosphomimetic Y39D mutation in VASP resulted in less accumulation of VASP at focal adhesions. VASP Y39D had a reduced affinity to the proline-rich region of zyxin. Interestingly, overexpression of both phosphomimetic and unphosphorylated forms of VASP, but not wild-type VASP, impaired adhesion of K562 cells to fibronectin. These results suggest that the phosphorylation and dephosphorylation cycle of VASP by the Abi-1-bridged mechanism regulates association of VASP with focal adhesions, which may regulate adhesion of Bcr-Abl-transformed leukaemic cells.
Collapse
|
7
|
Abstract
Abstract
Understanding the cellular mechanisms of platelet activation and their pharmacologic modulation is of major interest for basic and clinical research. Here we introduce a comprehensive human platelet repository (PlateletWeb) for systems biologic analysis of platelets in the functional context of integrated networks. Functional, drug, and pathway associations provide a first systemic insight into various aspects of platelet functionality and pharmacologic regulation. Detailed manual curation of recent platelet proteome and transcriptome studies yielded more than 5000 platelet proteins. Integration of protein-protein interactions with kinase-substrate relationships unraveled the platelet signaling network involving more than 70% of all platelet proteins. Analysis of the platelet kinome in the context of the kinase phylogenetic background revealed an over-representation of tyrosine kinase substrates. The extraction and graphical visualization of specific subnetworks allow identification of all major signaling modules involved in activation and inhibition. An in-depth analysis of DOK1 signaling identifies putative signal modulators of the integrin network. Through integration of various information sources and high curation standards, the PlateletWeb knowledge base offers the systems biologic background for the investigation of signal transduction in human platelets (http://plateletweb.bioapps.biozentrum.uni-wuerzburg.de).
Collapse
|
8
|
Abstract
Platelets pose unique challenges to cell biologists due to their lack of nucleus and low levels of messenger RNA. Platelets cannot be cultured in great abundance or manipulated using common recombinant DNA technologies. As a result, platelet research has lagged behind that of nucleated cells. The advent of mass spectrometry and its application to protein biochemistry brought with it great hopes for the platelet community that are now being realized. This technology is ideally suited for identifying low-abundance proteins, protein-protein interactions, and post-translational modifications in complex protein mixtures. Over the past 10 years, proteomics has delivered in many ways, providing platelet biologists with a comprehensive list of proteins expressed in platelets, information on post-translational modifications, protein interactions and sub-cellular localization. Several novel and important platelet membrane proteins, including CLEC-2, CD148, G6b-B, G6f, and Hsp47, have been identified using proteomics-based approaches. New, more sensitive instrumentation and novel approaches are making it increasingly possible to identify ever lower amounts of proteins. In this chapter we highlight some of the major achievements of platelet proteomics to date, discussing challenges and how they were overcome. We also discuss new frontiers and applications of proteomics to platelets and microparticles in health and disease, as we strive to better understand the molecular mechanisms underlying the platelet response to vascular injury.
Collapse
Affiliation(s)
- Yotis Senis
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK.
| | | |
Collapse
|
9
|
Wangorsch G, Butt E, Mark R, Hubertus K, Geiger J, Dandekar T, Dittrich M. Time-resolved in silico modeling of fine-tuned cAMP signaling in platelets: feedback loops, titrated phosphorylations and pharmacological modulation. BMC SYSTEMS BIOLOGY 2011; 5:178. [PMID: 22034949 PMCID: PMC3247139 DOI: 10.1186/1752-0509-5-178] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 10/28/2011] [Indexed: 02/13/2023]
Abstract
Background Hemostasis is a critical and active function of the blood mediated by platelets. Therefore, the prevention of pathological platelet aggregation is of great importance as well as of pharmaceutical and medical interest. Endogenous platelet inhibition is predominantly based on cyclic nucleotides (cAMP, cGMP) elevation and subsequent cyclic nucleotide-dependent protein kinase (PKA, PKG) activation. In turn, platelet phosphodiesterases (PDEs) and protein phosphatases counterbalance their activity. This main inhibitory pathway in human platelets is crucial for countervailing unwanted platelet activation. Consequently, the regulators of cyclic nucleotide signaling are of particular interest to pharmacology and therapeutics of atherothrombosis. Modeling of pharmacodynamics allows understanding this intricate signaling and supports the precise description of these pivotal targets for pharmacological modulation. Results We modeled dynamically concentration-dependent responses of pathway effectors (inhibitors, activators, drug combinations) to cyclic nucleotide signaling as well as to downstream signaling events and verified resulting model predictions by experimental data. Experiments with various cAMP affecting compounds including anti-platelet drugs and their combinations revealed a high fidelity, fine-tuned cAMP signaling in platelets without cross-talk to the cGMP pathway. The model and the data provide evidence for two independent feedback loops: PKA, which is activated by elevated cAMP levels in the platelet, subsequently inhibits adenylyl cyclase (AC) but as well activates PDE3. By multi-experiment fitting, we established a comprehensive dynamic model with one predictive, optimized and validated set of parameters. Different pharmacological conditions (inhibition, activation, drug combinations, permanent and transient perturbations) are successfully tested and simulated, including statistical validation and sensitivity analysis. Downstream cyclic nucleotide signaling events target different phosphorylation sites for cAMP- and cGMP-dependent protein kinases (PKA, PKG) in the vasodilator-stimulated phosphoprotein (VASP). VASP phosphorylation as well as cAMP levels resulting from different drug strengths and combined stimulants were quantitatively modeled. These predictions were again experimentally validated. High sensitivity of the signaling pathway at low concentrations is involved in a fine-tuned balance as well as stable activation of this inhibitory cyclic nucleotide pathway. Conclusions On the basis of experimental data, literature mining and database screening we established a dynamic in silico model of cyclic nucleotide signaling and probed its signaling sensitivity. Thoroughly validated, it successfully predicts drug combination effects on platelet function, including synergism, antagonism and regulatory loops.
Collapse
Affiliation(s)
- Gaby Wangorsch
- Department of Bioinformatics, Biocenter, University of Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|