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Huang M, Lu L, Lin C, Zheng Y, Pan X, Wang S, Chen S, Zhang Y, Liu C, Ge G, Zeng YA, Chen J. LRP12 is an endogenous transmembrane inactivator of α4 integrins. Cell Rep 2023; 42:112667. [PMID: 37330909 DOI: 10.1016/j.celrep.2023.112667] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 04/26/2023] [Accepted: 06/02/2023] [Indexed: 06/20/2023] Open
Abstract
Dynamic regulation of integrin activation and inactivation is critical for precisely controlled cell adhesion and migration in physiological and pathological processes. The molecular basis for integrin activation has been intensively studied; however, the understanding of integrin inactivation is still limited. Here, we identify LRP12 as an endogenous transmembrane inhibitor for α4 integrin activation. The LRP12 cytoplasmic domain directly binds to the integrin α4 cytoplasmic tail and inhibits talin binding to the β subunit, thus keeping integrin inactive. In migrating cells, LRP12-α4 interaction induces nascent adhesion (NA) turnover at the leading-edge protrusion. Knockdown of LRP12 leads to increased NAs and enhanced cell migration. Consistently, LRP12-deficient T cells show an enhanced homing capability in mice and lead to aggravated chronic colitis in a T cell-transfer colitis model. Altogether, LRP12 is a transmembrane inactivator for integrins that inhibits α4 integrin activation and controls cell migration by maintaining balanced NA dynamics.
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Affiliation(s)
- MengWen Huang
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Ling Lu
- Department of Pathology, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai 200072, China
| | - ChangDong Lin
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai 200092, China; Frontier Science Center for Stem Cell Research, Tongji University, Shanghai 200092, China
| | - YaJuan Zheng
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - XingChao Pan
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - ShiHui Wang
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - ShiYang Chen
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - YouHua Zhang
- Department of Pathology, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai 200072, China
| | - ChunYe Liu
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - GaoXiang Ge
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yi Arial Zeng
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - JianFeng Chen
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
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2
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Lovett BM, Hill KE, Randolph EM, Wang L, Schwarzbauer JE. Nucleation of fibronectin fibril assembly requires binding between heparin and the 13th type III module of fibronectin. J Biol Chem 2023; 299:104622. [PMID: 36933809 PMCID: PMC10124947 DOI: 10.1016/j.jbc.2023.104622] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023] Open
Abstract
Fibronectin (FN), a critical component of the extracellular matrix, is assembled into fibrils through a cell-mediated process. Heparan sulfate (HS) binds to the III13 module of FN, and fibroblasts lacking this glycosaminoglycan exhibit reduced FN fibril assembly. To determine if HS depends on III13 to control FN assembly, we deleted both III13 alleles in NIH 3T3 cells using the CRISPR-Cas9 system. ΔIII13 cells assembled fewer FN matrix fibrils and less DOC-insoluble FN matrix than wildtype cells. Little if any mutant FN matrix was assembled when purified ΔIII13 FN was provided to Chinese hamster ovary (CHO) cells, showing that lack of III13 caused the deficiency in assembly by ΔIII13 cells. Addition of heparin promoted the assembly of wildtype FN by CHO cells, but it had no effect on the assembly of ΔIII13 FN. Furthermore, heparin binding stabilized the folded conformation of III13 and prevented it from self-associating with increasing temperature suggesting that stabilization by HS/heparin binding might regulate interactions between III13 and other FN modules. This effect would be particularly important at matrix assembly sites where our data show that ΔIII13 cells require both exogenous wildtype FN and heparin in the culture medium to maximize assembly site formation. Our results show that heparin-promoted growth of fibril nucleation sites is dependent on III13. We conclude that HS/heparin binds to III13 to promote and control the nucleation and development of FN fibrils.
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Affiliation(s)
- Benjamin M Lovett
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Katherine E Hill
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Ellie M Randolph
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Luqiong Wang
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Jean E Schwarzbauer
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
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Li W, Wen L, Rathod B, Gingras AC, Ley K, Lee HS. Kindlin2 enables EphB/ephrinB bi-directional signaling to support vascular development. Life Sci Alliance 2023; 6:e202201800. [PMID: 36574991 PMCID: PMC9795039 DOI: 10.26508/lsa.202201800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/28/2022] Open
Abstract
Direct contact between cells expressing either ephrin ligands or Eph receptor tyrosine kinase produces diverse developmental responses. Transmembrane ephrinB ligands play active roles in transducing bi-directional signals downstream of EphB/ephrinB interaction. However, it has not been well understood how ephrinB relays transcellular signals to neighboring cells and what intracellular effectors are involved. Here, we report that kindlin2 can mediate bi-directional ephrinB signaling through binding to a highly conserved NIYY motif in the ephrinB2 cytoplasmic tail. We show this interaction is important for EphB/ephrinB-mediated integrin activation in mammalian cells and for blood vessel morphogenesis during zebrafish development. A mixed two-cell population study revealed that kindlin2 (in ephrinB2-expressing cells) modulates transcellular EphB4 activation by promoting ephrinB2 clustering. This mechanism is also operative for EphB2/ephrinB1, suggesting that kindlin2-mediated regulation is conserved for EphB/ephrinB signaling pathways. Together, these findings show that kindlin2 enables EphB4/ephrinB2 bi-directional signal transmission.
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Affiliation(s)
- Wenqing Li
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Lai Wen
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Bhavisha Rathod
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Klaus Ley
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Ho-Sup Lee
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
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Song G, Meng F, Luo B. The β
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integrin EGF domains support a constitutive extended conformation, and the cytoplasmic domain impairs outside‐in signaling. J Cell Physiol 2022; 237:4251-4261. [DOI: 10.1002/jcp.30871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/28/2022] [Accepted: 08/27/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Guannan Song
- Department of Biological Sciences Louisiana State University Baton Rouge Louisiana USA
| | - Fei Meng
- Department of Biological Sciences Louisiana State University Baton Rouge Louisiana USA
| | - Bing‐Hao Luo
- Department of Biological Sciences Louisiana State University Baton Rouge Louisiana USA
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Lee HS, Sun H, Lagarrigue F, Kim SHJ, Fox JW, Sherman NE, Gingras AR, Ginsberg MH. Phostensin enables lymphocyte integrin activation and population of peripheral lymphoid organs. J Exp Med 2022; 219:e20211637. [PMID: 35766979 PMCID: PMC9247717 DOI: 10.1084/jem.20211637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 01/17/2022] [Accepted: 03/28/2022] [Indexed: 02/03/2023] Open
Abstract
Rap1 GTPase drives assembly of the Mig-10/RIAM/Lamellipodin (MRL protein)-integrin-talin (MIT) complex that enables integrin-dependent lymphocyte functions. Here we used tandem affinity tag-based proteomics to isolate and analyze the MIT complex and reveal that Phostensin (Ptsn), a regulatory subunit of protein phosphatase 1, is a component of the complex. Ptsn mediates dephosphorylation of Rap1, thereby preserving the activity and membrane localization of Rap1 to stabilize the MIT complex. CRISPR/Cas9-induced deletion of PPP1R18, which encodes Ptsn, markedly suppresses integrin activation in Jurkat human T cells. We generated apparently healthy Ppp1r18-/- mice that manifest lymphocytosis and reduced population of peripheral lymphoid tissues ascribable, in part, to defective activation of integrins αLβ2 and α4β7. Ppp1r18-/- T cells exhibit reduced capacity to induce colitis in a murine adoptive transfer model. Thus, Ptsn enables lymphocyte integrin-mediated functions by dephosphorylating Rap1 to stabilize the MIT complex. As a consequence, loss of Ptsn ameliorates T cell-mediated colitis.
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Affiliation(s)
- Ho-Sup Lee
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Hao Sun
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Frédéric Lagarrigue
- Department of Medicine, University of California, San Diego, La Jolla, CA
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, Centre National de la Recherche Scientifique, Université Paul Sabatier, Toulouse, France
| | - Sarah Hyun Ji Kim
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jay W. Fox
- School of Medicine, University of Virginia, Charlottesville, VA
| | | | | | - Mark H. Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA
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6
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Castroflorio E, Pérez Berná AJ, López-Márquez A, Badosa C, Loza-Alvarez P, Roldán M, Jiménez-Mallebrera C. The Capillary Morphogenesis Gene 2 Triggers the Intracellular Hallmarks of Collagen VI-Related Muscular Dystrophy. Int J Mol Sci 2022; 23:ijms23147651. [PMID: 35886995 PMCID: PMC9322809 DOI: 10.3390/ijms23147651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 11/16/2022] Open
Abstract
Collagen VI-related disorders (COL6-RD) represent a severe form of congenital disease for which there is no treatment. Dominant-negative pathogenic variants in the genes encoding α chains of collagen VI are the main cause of COL6-RD. Here we report that patient-derived fibroblasts carrying a common single nucleotide variant mutation are unable to build the extracellular collagen VI network. This correlates with the intracellular accumulation of endosomes and lysosomes triggered by the increased phosphorylation of the collagen VI receptor CMG2. Notably, using a CRISPR-Cas9 gene-editing tool to silence the dominant-negative mutation in patients’ cells, we rescued the normal extracellular collagen VI network, CMG2 phosphorylation levels, and the accumulation of endosomes and lysosomes. Our findings reveal an unanticipated role of CMG2 in regulating endosomal and lysosomal homeostasis and suggest that mutated collagen VI dysregulates the intracellular environment in fibroblasts in collagen VI-related muscular dystrophy.
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Affiliation(s)
- Enrico Castroflorio
- ICFO-The Institute of Photonic Sciences, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain;
- Correspondence: (E.C.); (C.J.-M.)
| | | | - Arístides López-Márquez
- Laboratorio de Investigación Aplicada en Enfermedades Neuromusculares, Unidad de Patología Neuromuscular, Servicio de Neuropediatría, Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain; (A.L.-M.); (C.B.)
- Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain;
- Centro de Investigaciones Biomédicas en Red de Enfermedades Rara (CIBERER), 28029 Madrid, Spain
| | - Carmen Badosa
- Laboratorio de Investigación Aplicada en Enfermedades Neuromusculares, Unidad de Patología Neuromuscular, Servicio de Neuropediatría, Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain; (A.L.-M.); (C.B.)
- Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain;
| | - Pablo Loza-Alvarez
- ICFO-The Institute of Photonic Sciences, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain;
| | - Mónica Roldán
- Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain;
- Unitat de Microscòpia Confocal i Imatge Cellular, Servei de Medicina Genètica i Molecular, Institut Pediàtric de Malaties Rares (IPER), Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
| | - Cecilia Jiménez-Mallebrera
- Laboratorio de Investigación Aplicada en Enfermedades Neuromusculares, Unidad de Patología Neuromuscular, Servicio de Neuropediatría, Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain; (A.L.-M.); (C.B.)
- Institut de Recerca Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain;
- Centro de Investigaciones Biomédicas en Red de Enfermedades Rara (CIBERER), 28029 Madrid, Spain
- Department of Genetics, University of Barcelona, 08028 Barcelona, Spain
- Correspondence: (E.C.); (C.J.-M.)
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Singam NSV, AlAdili B, Amraotkar AR, Coulter AR, Singh A, Kulkarni S, Mitra R, Daham ON, Smith AE, DeFilippis AP. In-vivo platelet activation and aggregation during and after acute atherothrombotic myocardial infarction in patients with and without Type-2 diabetes mellitus treated with ticagrelor. Vascul Pharmacol 2022; 145:107000. [PMID: 35623547 DOI: 10.1016/j.vph.2022.107000] [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: 01/05/2022] [Revised: 03/30/2022] [Accepted: 05/20/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Patients with type-2 diabetes are twice as likely to suffer from acute myocardial infarction (AMI) and have a higher incidence of recurrent events than their non-diabetic counterparts. Ticagrelor is a platelet inhibitor known to reduce major adverse cardiovascular events (MACE) in AMI patients. This study measures the level and change in platelet activation and aggregation at the time of and following an AMI in patients with and without diabetes treated with ticagrelor. MATERIALS/METHODS P2Y12 receptor inhibitor naïve patients presenting with AMI were prospectively enrolled. Blood collection occurred before coronary angiography (baseline: T0), 2, 4, 24, 48 h after baseline, and at a three-month follow-up. Ticagrelor was administered within five minutes of T0. We assessed platelet activation via measurements of surface P-selectin and platelet activated glycoprotein IIb/IIIa-1 (PAC-1) and assessed platelet aggregation via monocyte, lymphocyte, and granulocyte aggregates. We hypothesize that platelet activation and aggregation will be proportionally impacted to the same degree by ticagrelor, regardless of diabetes status. RESULTS Ninety-seven patients were prospectively enrolled (diabetes, N = 33; no diabetes, N = 64). No difference was observed in the expression of P-selectin and PAC-1 at any given point between diabetes and non-diabetes groups (p > 0.05). No difference was observed in the percentage of platelet bound to leukocytes at any measured timepoint between patients with and without diabetes (p > 0.05). Platelet leukocyte aggregation was suppressed during the acute phase compared to quiescence equally among both groups. DISCUSSION Ticagrelor demonstrated similar in-vivo effects on platelet activation and aggregation regardless of diabetes status in patients presenting with AMI.
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Affiliation(s)
- Narayana Sarma V Singam
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Bahjat AlAdili
- Department of Medicine, University of Louisville, Louisville, KY, United States of America
| | - Alok R Amraotkar
- Division of Cardiovascular Medicine, University of Louisville, Louisville, KY, United States of America
| | - Amanda R Coulter
- Division of Cardiovascular Medicine, University of Louisville, Louisville, KY, United States of America
| | - Ayesha Singh
- Division of Cardiovascular Medicine, University of Louisville, Louisville, KY, United States of America
| | - Siddhesh Kulkarni
- Division of Bioinformatics and Biostatistics, University of Louisville, United States of America
| | - Riten Mitra
- Division of Bioinformatics and Biostatistics, University of Louisville, United States of America
| | - Omar Noori Daham
- Division of Cardiovascular Medicine, University of Louisville, Louisville, KY, United States of America
| | - Allison E Smith
- Division of Cardiovascular Medicine, University of Louisville, Louisville, KY, United States of America
| | - Andrew P DeFilippis
- Division of Cardiovascular Medicine, Vanderbilt University, Nashville, KY, United States of America
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Wang Z, Zhu J. Structural determinants of the integrin transmembrane domain required for bidirectional signal transmission across the cell membrane. J Biol Chem 2021; 297:101318. [PMID: 34678312 PMCID: PMC8569584 DOI: 10.1016/j.jbc.2021.101318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/12/2021] [Accepted: 10/18/2021] [Indexed: 11/26/2022] Open
Abstract
Studying the tight activity regulation of platelet-specific integrin αIIbβ3 is foundational and paramount to our understanding of integrin structure and activation. αIIbβ3 is essential for the aggregation and adhesion function of platelets in hemostasis and thrombosis. Structural and mutagenesis studies have previously revealed the critical role of αIIbβ3 transmembrane (TM) association in maintaining the inactive state. Gain-of-function TM mutations were identified and shown to destabilize the TM association leading to integrin activation. Studies using isolated TM peptides have suggested an altered membrane embedding of the β3 TM α-helix coupled with αIIbβ3 activation. However, controversies remain as to whether and how the TM α-helices change their topologies in the context of full-length integrin in native cell membrane. In this study, we utilized proline scanning mutagenesis and cysteine scanning accessibility assays to analyze the structure and function correlation of the αIIbβ3 TM domain. Our identification of loss-of-function proline mutations in the TM domain suggests the requirement of a continuous TM α-helical structure in transmitting activation signals bidirectionally across the cell membrane, characterized by the inside-out activation for ligand binding and the outside-in signaling for cell spreading. Similar results were found for αLβ2 and α5β1 TM domains, suggesting a generalizable mechanism. We also detected a topology change of β3 TM α-helix within the cell membrane, but only under conditions of cell adhesion and the absence of αIIb association. Our data demonstrate the importance of studying the structure and function of the integrin TM domain in the native cell membrane.
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Affiliation(s)
- Zhengli Wang
- Blood Research Institute, Versiti, Milwaukee, Wisconsin, USA
| | - Jieqing Zhu
- Blood Research Institute, Versiti, Milwaukee, Wisconsin, USA; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Narasimhan BN, Horrocks MS, Malmström J. Hydrogels with Tunable Physical Cues and Their Emerging Roles in Studies of Cellular Mechanotransduction. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Badri Narayanan Narasimhan
- Department of Chemical and Materials Engineering University of Auckland Private Bag 92019 Auckland 1142 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology Victoria University of Wellington PO Box 600 Wellington 6140 New Zealand
| | - Matthew S. Horrocks
- Department of Chemical and Materials Engineering University of Auckland Private Bag 92019 Auckland 1142 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology Victoria University of Wellington PO Box 600 Wellington 6140 New Zealand
| | - Jenny Malmström
- Department of Chemical and Materials Engineering University of Auckland Private Bag 92019 Auckland 1142 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology Victoria University of Wellington PO Box 600 Wellington 6140 New Zealand
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Sun G, Guillon E, Holley SA. Integrin intra-heterodimer affinity inversely correlates with integrin activatability. Cell Rep 2021; 35:109230. [PMID: 34107244 PMCID: PMC8227800 DOI: 10.1016/j.celrep.2021.109230] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/13/2021] [Accepted: 05/17/2021] [Indexed: 11/21/2022] Open
Abstract
Integrins are heterodimeric cell surface receptors composed of an α and β subunit that mediate cell adhesion to extracellular matrix proteins such as fibronectin. We previously studied integrin α5β1 activation during zebrafish somitogenesis, and in the present study, we characterize the integrin αV fibronectin receptors. Integrins are activated via a conformational change, and we perform single-molecule biophysical measurements of both integrin activation via fluorescence resonance energy transfer (FRET)-fluorescence lifetime imaging microscopy (FLIM) and integrin intra-heterodimer stability via fluorescence cross-correlation spectroscopy (FCCS) in living embryos. We find that integrin heterodimers that exhibit robust cell surface expression, including αVβ3, αVβ5, and αVβ6, are never activated in this in vivo context, even in the presence of fibronectin matrix. In contrast, activatable integrins, such as integrin αVβ1, and alleles of αVβ3, αVβ5, αVβ6 that are biased to the active conformation exhibit poor cell surface expression and have a higher intra-heterodimer dissociation constant (KD). These observations suggest that a weak integrin intra-heterodimer affinity decreases integrin cell surface stability and increases integrin activatability.
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Affiliation(s)
- Guangyu Sun
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06520, USA
| | - Emilie Guillon
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06520, USA
| | - Scott A Holley
- Department of Molecular, Cellular and Developmental Biology, Yale University, 260 Whitney Avenue, New Haven, CT 06520, USA.
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11
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Liao Z, Gingras AR, Lagarrigue F, Ginsberg MH, Shattil SJ. Optogenetics-based localization of talin to the plasma membrane promotes activation of β3 integrins. J Biol Chem 2021; 296:100675. [PMID: 33865854 PMCID: PMC8131925 DOI: 10.1016/j.jbc.2021.100675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/01/2021] [Accepted: 04/14/2021] [Indexed: 11/30/2022] Open
Abstract
Interaction of talin with the cytoplasmic tails of integrin β triggers integrin activation, leading to an increase of integrin affinity/avidity for extracellular ligands. In talin KO mice, loss of talin interaction with platelet integrin αIIbβ3 causes a severe hemostatic defect, and loss of talin interaction with endothelial cell integrin αVβ3 affects angiogenesis. In normal cells, talin is autoinhibited and localized in the cytoplasm. Here, we used an optogenetic platform to assess whether recruitment of full-length talin to the plasma membrane was sufficient to induce integrin activation. A dimerization module (Arabidopsis cryptochrome 2 fused to the N terminus of talin; N-terminal of cryptochrome-interacting basic helix-loop-helix domain ended with a CAAX box protein [C: cysteine; A: aliphatic amino acid; X: any C-terminal amino acid]) responsive to 450 nm (blue) light was inserted into Chinese hamster ovary cells and endothelial cells also expressing αIIbβ3 or αVβ3, respectively. Thus, exposure of the cells to blue light caused a rapid and reversible recruitment of Arabidopsis cryptochrome 2-talin to the N-terminal of cryptochrome-interacting basic helix-loop-helix domain ended with a CAAX box protein [C: cysteine; A: aliphatic amino acid; X: any C-terminal amino acid]-decorated plasma membrane. This resulted in β3 integrin activation in both cell types, as well as increasing migration of the endothelial cells. However, membrane recruitment of talin was not sufficient for integrin activation, as membrane-associated Ras-related protein 1 (Rap1)-GTP was also required. Moreover, talin mutations that interfered with its direct binding to Rap1 abrogated β3 integrin activation. Altogether, these results define a role for the plasma membrane recruitment of talin in β3 integrin activation, and they suggest a nuanced sequence of events thereafter involving Rap1-GTP.
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Affiliation(s)
- Zhongji Liao
- Department of Medicine, University of California, San Diego, La Jolla, California, USA.
| | - Alexandre R Gingras
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Frederic Lagarrigue
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Sanford J Shattil
- Department of Medicine, University of California, San Diego, La Jolla, California, USA.
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12
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Kadry YA, Maisuria EM, Huet-Calderwood C, Calderwood DA. Differences in self-association between kindlin-2 and kindlin-3 are associated with differential integrin binding. J Biol Chem 2020; 295:11161-11173. [PMID: 32546480 DOI: 10.1074/jbc.ra120.013618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/03/2020] [Indexed: 12/15/2022] Open
Abstract
The integrin family of transmembrane adhesion receptors coordinates complex signaling networks that control the ability of cells to sense and communicate with the extracellular environment. Kindlin proteins are a central cytoplasmic component of these networks, directly binding integrin cytoplasmic domains and mediating interactions with cytoskeletal and signaling proteins. The physiological importance of kindlins is well established, but how the scaffolding functions of kindlins are regulated at the molecular level is still unclear. Here, using a combination of GFP nanotrap association assays, pulldown and integrin-binding assays, and live-cell imaging, we demonstrate that full-length kindlins can oligomerize (self-associate) in mammalian cells, and we propose that this self-association inhibits integrin binding and kindlin localization to focal adhesions. We show that both kindlin-2 and kindlin-3 can self-associate and that kindlin-3 self-association is more robust. Using chimeric mapping, we demonstrate that the F2PH and F3 subdomains are important for kindlin self-association. Through comparative sequence analysis of kindlin-2 and kindlin-3, we identify kindlin-3 point mutations that decrease self-association and enhance integrin binding, affording mutant kindlin-3 the ability to localize to focal adhesions. Our results support the notion that kindlin self-association negatively regulates integrin binding.
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Affiliation(s)
- Yasmin A Kadry
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA
| | - Eesha M Maisuria
- Department of Molecular Biophysics and Biochemistry, Yale College, Yale University, New Haven, Connecticut, USA
| | | | - David A Calderwood
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA .,Department of Cell Biology, Yale University, New Haven, Connecticut, USA
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13
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Vega ME, Kastberger B, Wehrle-Haller B, Schwarzbauer JE. Stimulation of Fibronectin Matrix Assembly by Lysine Acetylation. Cells 2020; 9:cells9030655. [PMID: 32182705 PMCID: PMC7140634 DOI: 10.3390/cells9030655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 12/31/2022] Open
Abstract
Diabetic nephropathy, a devastating consequence of diabetes mellitus, is characterized by the accumulation of extracellular matrix (ECM) that disrupts the kidney's filtration apparatus. Elevated glucose levels increase the deposition of a fibronectin (FN) matrix by mesangial cells, the primary matrix-producing cells of the kidney, and also increase acetyl-CoA leading to higher levels of lysine acetylation. Here, we investigated the connection between acetylation and the ECM and show that treatment of mesangial cells with deacetylase inhibitors increases both acetylation and FN matrix assembly compared to untreated cells. The matrix effects were linked to lysine 794 (K794) in the β1 integrin cytoplasmic domain based on studies of cells expressing acetylated (K794Q) and non-acetylated (K794R) mimetics. β1(K794Q) cells assembled significantly more FN matrix than wildtype β1 cells, while the non-acetylated β1(K794R) form was inactive. We show that mutation of K794 affects FN assembly by stimulating integrin-FN binding activity and cell contractility. Wildtype and β1(K794Q) cells but not β1(K794R) cells further increased their FN matrix when stimulated with deacetylase inhibitors indicating that increased acetylation on other proteins is required for maximum FN assembly. Thus, lysine acetylation provides a mechanism for glucose-induced fibrosis by up-regulation of FN matrix assembly.
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Affiliation(s)
- Maria E. Vega
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA;
| | - Birgit Kastberger
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, 1 Rue Michel-Servet, CMU, 1211 Geneva 4, Switzerland; (B.K.); (B.W.-H.)
| | - Bernhard Wehrle-Haller
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, 1 Rue Michel-Servet, CMU, 1211 Geneva 4, Switzerland; (B.K.); (B.W.-H.)
| | - Jean E. Schwarzbauer
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA;
- Correspondence: ; Tel.: +609-258-2893; Fax: +609-258-1035
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14
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Extracellular matrix-cell interactions: Focus on therapeutic applications. Cell Signal 2019; 66:109487. [PMID: 31778739 DOI: 10.1016/j.cellsig.2019.109487] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 02/06/2023]
Abstract
Extracellular matrix (ECM) macromolecules together with a multitude of different molecules residing in the extracellular space play a vital role in the regulation of cellular phenotype and behavior. This is achieved via constant reciprocal interactions between the molecules of the ECM and the cells. The ECM-cell interactions are mediated via cell surface receptors either directly or indirectly with co-operative molecules. The ECM is also under perpetual remodeling process influencing cell-signaling pathways on its part. The fragmentation of ECM macromolecules provides even further complexity for the intricate environment of the cells. However, as long as the interactions between the ECM and the cells are in balance, the health of the body is retained. Alternatively, any dysregulation in these interactions can lead to pathological processes and finally to various diseases. Thus, therapeutic applications that are based on retaining normal ECM-cell interactions are highly rationale. Moreover, in the light of the current knowledge, also concurrent multi-targeting of the complex ECM-cell interactions is required for potent pharmacotherapies to be developed in the future.
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15
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Penke LR, Peters-Golden M. Molecular determinants of mesenchymal cell activation in fibroproliferative diseases. Cell Mol Life Sci 2019; 76:4179-4201. [PMID: 31563998 PMCID: PMC6858579 DOI: 10.1007/s00018-019-03212-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/01/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023]
Abstract
Uncontrolled scarring, or fibrosis, can interfere with the normal function of virtually all tissues of the body, ultimately leading to organ failure and death. Fibrotic diseases represent a major cause of death in industrialized countries. Unfortunately, no curative treatments for these conditions are yet available, highlighting the critical need for a better fundamental understanding of molecular mechanisms that may be therapeutically tractable. The ultimate indispensable effector cells responsible for deposition of extracellular matrix proteins that comprise scars are mesenchymal cells, namely fibroblasts and myofibroblasts. In this review, we focus on the biology of these cells and the molecular mechanisms that regulate their pertinent functions. We discuss key pro-fibrotic mediators, signaling pathways, and transcription factors that dictate their activation and persistence. Because of their possible clinical and therapeutic relevance, we also consider potential brakes on mesenchymal cell activation and cellular processes that may facilitate myofibroblast clearance from fibrotic tissue-topics that have in general been understudied.
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Affiliation(s)
- Loka R Penke
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109-5642, USA
| | - Marc Peters-Golden
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109-5642, USA.
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16
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Erusappan P, Alam J, Lu N, Zeltz C, Gullberg D. Integrin α11 cytoplasmic tail is required for FAK activation to initiate 3D cell invasion and ERK-mediated cell proliferation. Sci Rep 2019; 9:15283. [PMID: 31653900 PMCID: PMC6814791 DOI: 10.1038/s41598-019-51689-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 09/10/2019] [Indexed: 12/31/2022] Open
Abstract
Integrin α11β1 is a collagen-binding integrin, which is receiving increasing attention in the context of wound healing and fibrosis. Although α11β1 integrin displays similar collagen specificity to α2β1 integrin, both integrins have distinct in vivo functions. In this context, the contribution of α11 subunit cytoplasmic tail interactions to diverse molecular signals and biological functions is largely unknown. In the current study, we have deleted the α11 cytoplasmic tail and studied the effect of this deletion on α11 integrin function. Compared to wild-type cells, C2C12 cells expressing tail-less α11 attached normally to collagen I, but formed fewer focal contacts. α11-tail-less cells furthermore displayed a reduced capacity to invade and reorganize a 3D collagen matrix and to proliferate. Analysis of cell signaling showed that FAK and ERK phosphorylation was reduced in cells expressing tail-less α11. Inhibition of ERK and FAK activation decreased α11-mediated cell proliferation, whereas α11-mediated cell invasion was FAK-dependent and occurred independently of ERK signaling. In summary, our data demonstrate that the integrin α11 cytoplasmic tail plays a central role in α11 integrin-specific functions, including FAK-dependent ERK activation to promote cell proliferation.
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Affiliation(s)
- Pugazendhi Erusappan
- Department of Biomedicine and Center of Cancer Biomarkers, University of Bergen, Jonas Lies vei 91, N-5009, Bergen, Norway.,Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, 0450, Oslo, Norway
| | - Jahedul Alam
- Department of Biomedicine and Center of Cancer Biomarkers, University of Bergen, Jonas Lies vei 91, N-5009, Bergen, Norway
| | - Ning Lu
- Department of Biomedicine and Center of Cancer Biomarkers, University of Bergen, Jonas Lies vei 91, N-5009, Bergen, Norway
| | - Cédric Zeltz
- Department of Biomedicine and Center of Cancer Biomarkers, University of Bergen, Jonas Lies vei 91, N-5009, Bergen, Norway.,Princess Margaret Cancer Center, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Donald Gullberg
- Department of Biomedicine and Center of Cancer Biomarkers, University of Bergen, Jonas Lies vei 91, N-5009, Bergen, Norway.
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17
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Novel compounds of hybrid structure pyridazinone–coumarin as potent inhibitors of platelet aggregation. Future Med Chem 2019; 11:2051-2062. [DOI: 10.4155/fmc-2018-0373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aim: The current limitations of antiplatelet therapy promote the search for new antithrombotic agents. Here we describe novel platelet aggregation inhibitors that combine pyridazinone and coumarin scaffolds in their structure. Results: The target compounds were synthesized in good yield from maleic anhydride, following a multistep strategy. The in vitro studies demonstrated significant antiplatelet activity in many of these compounds, with IC50 values in the low micromolar range, revealing that the activity was affected by the substitution pattern of the two selected cores. Additional studies point out their effect as inhibitors of glycoprotein (Gp) IIb/IIIa activation. Conclusion: This novel hybrid structure can be considered a good prototype for the development of potent platelet aggregation inhibitors.
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18
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Gingras AR, Lagarrigue F, Cuevas MN, Valadez AJ, Zorovich M, McLaughlin W, Lopez-Ramirez MA, Seban N, Ley K, Kiosses WB, Ginsberg MH. Rap1 binding and a lipid-dependent helix in talin F1 domain promote integrin activation in tandem. J Cell Biol 2019; 218:1799-1809. [PMID: 30988001 PMCID: PMC6548133 DOI: 10.1083/jcb.201810061] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/11/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023] Open
Abstract
Rap1 GTPases bind effectors, such as RIAM, to enable talin1 to induce integrin activation. In addition, Rap1 binds directly to the talin1 F0 domain (F0); however, this interaction makes a limited contribution to integrin activation in CHO cells or platelets. Here, we show that talin1 F1 domain (F1) contains a previously undetected Rap1-binding site of similar affinity to that in F0. A structure-guided point mutant (R118E) in F1, which blocks Rap1 binding, abolishes the capacity of Rap1 to potentiate talin1-induced integrin activation. The capacity of F1 to mediate Rap1-dependent integrin activation depends on a unique loop in F1 that has a propensity to form a helix upon binding to membrane lipids. Basic membrane-facing residues of this helix are critical, as charge-reversal mutations led to dramatic suppression of talin1-dependent activation. Thus, a novel Rap1-binding site and a transient lipid-dependent helix in F1 work in tandem to enable a direct Rap1-talin1 interaction to cause integrin activation.
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Affiliation(s)
| | | | - Monica N Cuevas
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Andrew J Valadez
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Marcus Zorovich
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wilma McLaughlin
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | | | - Nicolas Seban
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, CA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA
| | - William B Kiosses
- Microscopy Core Facility, La Jolla Institute for Immunology, La Jolla, CA
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA
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19
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20
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Kadry YA, Huet-Calderwood C, Simon B, Calderwood DA. Kindlin-2 interacts with a highly conserved surface of ILK to regulate focal adhesion localization and cell spreading. J Cell Sci 2018; 131:jcs.221184. [PMID: 30254023 DOI: 10.1242/jcs.221184] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/17/2018] [Indexed: 12/27/2022] Open
Abstract
The integrin-associated adaptor proteins integrin-linked kinase (ILK) and kindlin-2 play central roles in integrin signaling and control of cell morphology. A direct ILK-kindlin-2 interaction is conserved across species and involves the F2PH subdomain of kindlin-2 and the pseudokinase domain (pKD) of ILK. However, complete understanding of the ILK-kindlin-2 interaction and its role in integrin-mediated signaling has been impeded by difficulties identifying the binding site for kindlin-2 on ILK. We used conservation-guided mapping to dissect the interaction between ILK and kindlin-2 and identified a previously unknown binding site for kindlin-2 on the C-lobe of the pKD of ILK. Mutations at this site inhibit binding to kindlin-2 while maintaining structural integrity of the pKD. Importantly, kindlin-binding-defective ILK mutants exhibit impaired focal adhesion localization and fail to fully rescue the spreading defects seen in ILK knockdown cells. Furthermore, kindlin-2 mutants with impaired ILK binding are also unable to fully support cell spreading. Thus, the interaction between ILK and kindlin-2 is critical for cell spreading and focal adhesion localization, representing a key signaling axis downstream of integrins.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Yasmin A Kadry
- From the Department of Pharmacology, Yale University, New Haven CT 06510, USA
| | | | - Bertrand Simon
- From the Department of Pharmacology, Yale University, New Haven CT 06510, USA
| | - David A Calderwood
- From the Department of Pharmacology, Yale University, New Haven CT 06510, USA .,Department of Cell Biology, Yale University, New Haven CT 06510, USA
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21
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Role of Extracellular Matrix in Development and Cancer Progression. Int J Mol Sci 2018; 19:ijms19103028. [PMID: 30287763 PMCID: PMC6213383 DOI: 10.3390/ijms19103028] [Citation(s) in RCA: 623] [Impact Index Per Article: 103.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 02/07/2023] Open
Abstract
The immense diversity of extracellular matrix (ECM) proteins confers distinct biochemical and biophysical properties that influence cell phenotype. The ECM is highly dynamic as it is constantly deposited, remodelled, and degraded during development until maturity to maintain tissue homeostasis. The ECM’s composition and organization are spatiotemporally regulated to control cell behaviour and differentiation, but dysregulation of ECM dynamics leads to the development of diseases such as cancer. The chemical cues presented by the ECM have been appreciated as key drivers for both development and cancer progression. However, the mechanical forces present due to the ECM have been largely ignored but recently recognized to play critical roles in disease progression and malignant cell behaviour. Here, we review the ways in which biophysical forces of the microenvironment influence biochemical regulation and cell phenotype during key stages of human development and cancer progression.
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22
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Lagarrigue F, Gingras AR, Paul DS, Valadez AJ, Cuevas MN, Sun H, Lopez-Ramirez MA, Goult BT, Shattil SJ, Bergmeier W, Ginsberg MH. Rap1 binding to the talin 1 F0 domain makes a minimal contribution to murine platelet GPIIb-IIIa activation. Blood Adv 2018; 2:2358-2368. [PMID: 30242097 PMCID: PMC6156890 DOI: 10.1182/bloodadvances.2018020487] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/11/2018] [Indexed: 01/08/2023] Open
Abstract
Activation of platelet glycoprotein IIb-IIIa (GPIIb-IIIa; integrin αIIbβ3) leads to high-affinity fibrinogen binding and platelet aggregation during hemostasis. Whereas GTP-bound Rap1 GTPase promotes talin 1 binding to the β3 cytoplasmic domain to activate platelet GPIIb-IIIa, the Rap1 effector that regulates talin association with β3 in platelets is unknown. Rap1 binding to the talin 1 F0 subdomain was proposed to forge the talin 1-Rap1 link in platelets. Here, we report a talin 1 point mutant (R35E) that significantly reduces Rap1 affinity without a significant effect on its structure or expression. Talin 1 head domain (THD) (R35E) was of similar potency to wild-type THD in activating αIIbβ3 in Chinese hamster ovary cells. Coexpression with activated Rap1b increased activation, and coexpression with Rap1GAP1 reduced activation caused by transfection of wild-type THD or THD(R35E). Furthermore, platelets from Tln1R35E/R35E mice showed similar GPIIb-IIIa activation to those from wild-type littermates in response to multiple agonists. Tln1R35E/R35E platelets exhibited slightly reduced platelet aggregation in response to low doses of agonists; however, there was not a significant hemostatic defect, as judged by tail bleeding times. Thus, the Rap1-talin 1 F0 interaction has little effect on platelet GPIIb-IIIa activation and hemostasis and cannot account for the dramatic effects of loss of Rap1 activity on these platelet functions.
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Affiliation(s)
| | | | - David S Paul
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Andrew J Valadez
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Monica N Cuevas
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Hao Sun
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | | | - Benjamin T Goult
- School of Biosciences, University of Kent, Kent, United Kingdom; and
| | - Sanford J Shattil
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wolfgang Bergmeier
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA
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23
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Jahan F, Madhavan S, Rolova T, Viazmina L, Grönholm M, Gahmberg CG. Phosphorylation of the α-chain in the integrin LFA-1 enables β2-chain phosphorylation and α-actinin binding required for cell adhesion. J Biol Chem 2018; 293:12318-12330. [PMID: 29903913 DOI: 10.1074/jbc.ra118.004318] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 06/11/2018] [Indexed: 11/06/2022] Open
Abstract
The integrin leukocyte function-associated antigen-1 (LFA-1) plays a pivotal role in leukocyte adhesion and migration, but the mechanism(s) by which this integrin is regulated has remained incompletely understood. LFA-1 integrin activity requires phosphorylation of its β2-chain and interactions of its cytoplasmic tail with various cellular proteins. The α-chain is constitutively phosphorylated and necessary for cellular adhesion, but how the α-chain regulates adhesion has remained enigmatic. We now show that substitution of the α-chain phosphorylation site (S1140A) in T cells inhibits the phosphorylation of the functionally important Thr-758 in the β2-chain, binding of α-actinin and 14-3-3 protein, and expression of an integrin-activating epitope after treatment with the stromal cell-derived factor-1α. The presence of this substitution resulted in a loss of cell adhesion and directional cell migration. Moreover, LFA-1 activation through the T-cell receptor in cells expressing the S1140A LFA-1 variant resulted in less Thr-758 phosphorylation, α-actinin and talin binding, and cell adhesion. The finding that the LFA-1 α-chain regulates adhesion through the β-chain via specific phosphorylation at Ser-1140 in the α-chain has not been previously reported and emphasizes that both chains are involved in the regulation of LFA-1 integrin activity.
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Affiliation(s)
- Farhana Jahan
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
| | - Sudarrshan Madhavan
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
| | - Taisia Rolova
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
| | - Larisa Viazmina
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
| | - Mikaela Grönholm
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
| | - Carl G Gahmberg
- From the Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Program, University of Helsinki, Helsinki 00014 UH, Finland
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24
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Affiliation(s)
- Andrew L. Frelinger
- Center for Platelet Research Studies, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA, USA
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25
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Pagani G, Gohlke H. On the contributing role of the transmembrane domain for subunit-specific sensitivity of integrin activation. Sci Rep 2018; 8:5733. [PMID: 29636500 PMCID: PMC5893634 DOI: 10.1038/s41598-018-23778-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/20/2018] [Indexed: 12/20/2022] Open
Abstract
Integrins are α/β heterodimeric transmembrane adhesion receptors. Evidence exists that their transmembrane domain (TMD) separates upon activation. Subunit-specific differences in activation sensitivity of integrins were reported. However, whether sequence variations in the TMD lead to differential TMD association has remained elusive. Here, we show by molecular dynamics simulations and association free energy calculations on TMDs of integrin αIIbβ3, αvβ3, and α5β1 that αIIbβ3 TMD is most stably associated; this difference is related to interaction differences across the TMDs. The order of TMD association stability is paralleled by the basal activity of these integrins, which suggests that TMD differences can have a decisive effect on integrin conformational free energies. We also identified a specific order of clasp disintegration upon TMD dissociation, which suggests that the closed state of integrins may comprise several microstates. Our results provide unprecedented insights into a possibly contributing role of TMD towards subunit-specific sensitivity of integrin activation.
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Affiliation(s)
- Giulia Pagani
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany.
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC) & Institute for Complex Systems - Structural Biochemistry (ICS 6), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
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26
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Thinn AMM, Wang Z, Zhu J. The membrane-distal regions of integrin α cytoplasmic domains contribute differently to integrin inside-out activation. Sci Rep 2018; 8:5067. [PMID: 29568062 PMCID: PMC5864728 DOI: 10.1038/s41598-018-23444-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/13/2018] [Indexed: 12/20/2022] Open
Abstract
Functioning as signal receivers and transmitters, the integrin α/β cytoplasmic tails (CT) are pivotal in integrin activation and signaling. 18 α integrin subunits share a conserved membrane-proximal region but have a highly diverse membrane-distal (MD) region at their CTs. Recent studies demonstrated that the presence of α CTMD region is essential for talin-induced integrin inside-out activation. However, it remains unknown whether the non-conserved α CTMD regions differently regulate the inside-out activation of integrin. Using αIIbβ3, αLβ2, and α5β1 as model integrins and by replacing their α CTMD regions with those of α subunits that pair with β3, β2, and β1 subunits, we analyzed the function of CTMD regions of 17 α subunits in talin-mediated integrin activation. We found that the α CTMD regions play two roles on integrin, which are activation-supportive and activation-regulatory. The regulatory but not the supportive function depends on the sequence identity of α CTMD region. A membrane-proximal tyrosine residue present in the CTMD regions of a subset of α integrins was identified to negatively regulate integrin inside-out activation. Our study provides a useful resource for investigating the function of α integrin CTMD regions.
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Affiliation(s)
- Aye Myat Myat Thinn
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, 53226, USA
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Zhengli Wang
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, 53226, USA
| | - Jieqing Zhu
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI, 53226, USA.
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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27
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Valdivia M, Vega-Macaya F, Olguín P. Mechanical Control of Myotendinous Junction Formation and Tendon Differentiation during Development. Front Cell Dev Biol 2017; 5:26. [PMID: 28386542 PMCID: PMC5362613 DOI: 10.3389/fcell.2017.00026] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/07/2017] [Indexed: 01/01/2023] Open
Abstract
The development of the musculoskeletal system is a great model to study the interplay between chemical and mechanical inter-tissue signaling in cell adhesion, tissue morphogenesis and differentiation. In both vertebrates and invertebrates (e.g., Drosophila melanogaster) the formation of muscle-tendon interaction generates mechanical forces which are required for myotendinous junction maturation and tissue differentiation. In addition, these forces must be withstood by muscles and tendons in order to prevent detachment from each other, deformation or even losing their integrity. Extracellular matrix remodeling at the myotendinous junction is key to resist mechanical load generated by muscle contraction. Recent evidences in vertebrates indicate that mechanical forces generated during junction formation regulate chemical signaling leading to extracellular matrix remodeling, however, the mechanotransduction mechanisms associated to this response remains elusive. In addition to extracellular matrix remodeling, the ability of Drosophila tendon-cells to bear mechanical load depends on rearrangement of tendon cell cytoskeleton, thus studying the molecular mechanisms involved in this process is critical to understand the contribution of mechanical forces to the development of the musculoskeletal system. Here, we review recent findings regarding the role of chemical and mechanical signaling in myotendinous junction formation and tendon differentiation, and discuss molecular mechanisms of mechanotransduction that may allow tendon cells to withstand mechanical load during development of the musculoskeletal system.
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Affiliation(s)
- Mauricio Valdivia
- Program in Human Genetics, Faculty of Medicine, Institute of Biomedical Sciences, Biomedical Neurosciences Institute, University of Chile Santiago, Chile
| | - Franco Vega-Macaya
- Program in Human Genetics, Faculty of Medicine, Institute of Biomedical Sciences, Biomedical Neurosciences Institute, University of Chile Santiago, Chile
| | - Patricio Olguín
- Program in Human Genetics, Faculty of Medicine, Institute of Biomedical Sciences, Biomedical Neurosciences Institute, University of Chile Santiago, Chile
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Kunschmann T, Puder S, Fischer T, Perez J, Wilharm N, Mierke CT. Integrin-linked kinase regulates cellular mechanics facilitating the motility in 3D extracellular matrices. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:580-593. [PMID: 28011283 DOI: 10.1016/j.bbamcr.2016.12.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/12/2016] [Accepted: 12/19/2016] [Indexed: 12/12/2022]
Abstract
The motility of cells plays an important role for many processes such as wound healing and malignant progression of cancer. The efficiency of cell motility is affected by the microenvironment. The connection between the cell and its microenvironment is facilitated by cell-matrix adhesion receptors and upon their activation focal adhesion proteins such as integrin-linked kinase (ILK) are recruited to sites of focal adhesion formation. In particular, ILK connects cell-matrix receptors to the actomyosin cytoskeleton. However, ILK's role in cell mechanics regulating cellular motility in 3D collagen matrices is still not well understood. We suggest that ILK facilitates 3D motility by regulating cellular mechanical properties such as stiffness and force transmission. Thus, ILK wild-type and knock-out cells are analyzed for their ability to migrate on 2D substrates serving as control and in dense 3D extracellular matrices. Indeed, ILK wild-type cells migrated faster on 2D substrates and migrated more numerous and deeper in 3D matrices. Hence, we analyzed cellular deformability, Young's modulus (stiffness) and adhesion forces. We found that ILK wild-type cells are less deformable (stiffer) and produce higher cell-matrix adhesion forces compared to ILK knock-out cells. Finally, ILK is essential for providing cellular mechanical stiffness regulating 3D motility.
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Affiliation(s)
- Tom Kunschmann
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany
| | - Stefanie Puder
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany
| | - Tony Fischer
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany
| | - Jeremy Perez
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany
| | - Nils Wilharm
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany
| | - Claudia Tanja Mierke
- University of Leipzig, Faculty of Physics and Earth Science, Institute for Experimental Physics I, Biological Physics Division, Linnestrasse 5, 04103 Leipzig, Germany.
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29
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Draheim KM, Huet-Calderwood C, Simon B, Calderwood DA. Nuclear Localization of Integrin Cytoplasmic Domain-associated Protein-1 (ICAP1) Influences β1 Integrin Activation and Recruits Krev/Interaction Trapped-1 (KRIT1) to the Nucleus. J Biol Chem 2016; 292:1884-1898. [PMID: 28003363 DOI: 10.1074/jbc.m116.762393] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/12/2016] [Indexed: 01/15/2023] Open
Abstract
Binding of ICAP1 (integrin cytoplasmic domain-associated protein-1) to the cytoplasmic tails of β1 integrins inhibits integrin activation. ICAP1 also binds to KRIT1 (Krev interaction trapped-1), a protein whose loss of function leads to cerebral cavernous malformation, a cerebrovascular dysplasia occurring in up to 0.5% of the population. We previously showed that KRIT1 functions as a switch for β1 integrin activation by antagonizing ICAP1-mediated inhibition of integrin activation. Here we use overexpression studies, mutagenesis, and flow cytometry to show that ICAP1 contains a functional nuclear localization signal and that nuclear localization impairs the ability of ICAP1 to suppress integrin activation. Moreover, we find that ICAP1 drives the nuclear localization of KRIT1 in a manner dependent upon a direct ICAP1/KRIT1 interaction. Thus, nuclear-cytoplasmic shuttling of ICAP1 influences both integrin activation and KRIT1 localization, presumably impacting nuclear functions of KRIT1.
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Affiliation(s)
- Kyle M Draheim
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Clotilde Huet-Calderwood
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Bertrand Simon
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - David A Calderwood
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520; the Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520.
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30
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Syed A, Arora N, Bunch TA, Smith EA. The role of a conserved membrane proximal cysteine in altering αPS2CβPS integrin diffusion. Phys Biol 2016; 13:066005. [PMID: 27848929 DOI: 10.1088/1478-3975/13/6/066005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cysteine residues (Cys) in the membrane proximal region are common post-translational modification (PTM) sites in transmembrane proteins. Herein, the effects of a highly conserved membrane proximal α-subunit Cys1368 on the diffusion properties of αPS2CβPS integrins are reported. Sequence alignment shows that this cysteine is palmitoylated in human α3 and α6 integrin subunits. Replacing Cys1368 in wild-type integrins with valine (Val1368) putatively blocks a PTM site and alters integrins' ligand binding and diffusion characteristics. Both fluorescence recovery after photobleaching (FRAP) and single particle tracking (SPT) diffusion measurements show Val1368 integrins are more mobile compared to wild-type integrins. Approximately 33% and 8% more Val1368 integrins are mobile as measured by FRAP and SPT, respectively. The mobile Val1368 integrins also exhibit less time-dependent diffusion, as measured by FRAP. Tandem mass spectrometry data suggest that Cys1368 contains a redox or palmitoylation PTM in αPS2CβPS integrins. This membrane proximal Cys may play an important role in the diffusion of other alpha subunits that contain this conserved residue.
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Affiliation(s)
- Aleem Syed
- Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50011, USA
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31
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Bennett JS. Regulation of integrins in platelets. Biopolymers 2016; 104:323-33. [PMID: 26010651 DOI: 10.1002/bip.22679] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 11/08/2022]
Abstract
Blood platelets prevent bleeding after trauma by forming occlusive aggregates at sites of vascular injury. Platelet aggregation is mediated by the integrin heterodimer αIIbβ3 and occurs when platelet agonists generated at the injury site convert αIIbβ3 from its resting to its active conformation. Active αIIbβ3 is then able to bind macromolecular ligands such as fibrinogen that crosslink adjacent platelets into hemostatic aggregates. Platelets circulate in a plasma milieu containing high concentrations of the principal αIIbβ3 ligand fibrinogen. Thus, αIIbβ3 activity is tightly regulated to prevent the spontaneous formation of platelet aggregates. αIIbβ3 activity is regulated at least three levels. First, intramolecular interactions involving motifs located in the membrane-proximal stalk regions, transmembrane domains, and the membrane-proximal cytosolic tails of αIIb and β3 maintain αIIbβ3 in its inactive conformation. Transmembrane domain interactions appear particularly important because disrupting these interactions causes constitutive αIIbβ3 activation. Second, the agonist-stimulated binding of the cytosolic proteins talin and kindlin-3 to the β3 cytosolic tail rapidly causes αIIbβ3 activation by disrupting the intramolecular interactions constraining αIIbβ3 activity. Third, the strength of ligand binding to active αIIbβ3 seems to be allosterically regulated. Thus, αIIbβ3 exists in a minimum of three interconvertible states: an inactive (resting) state that does not interact with ligands and two active ligand binding states that differ in their affinity for fibrinogen and in the mechanical stability of fibrinogen complexes they form.
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Affiliation(s)
- Joel S Bennett
- Hematology-Oncology Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania Philadelphia, 19104, Pennsylvania
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32
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Jaqaman K, Galbraith JA, Davidson MW, Galbraith CG. Changes in single-molecule integrin dynamics linked to local cellular behavior. Mol Biol Cell 2016; 27:1561-9. [PMID: 27009207 PMCID: PMC4865314 DOI: 10.1091/mbc.e16-01-0018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/16/2016] [Indexed: 12/14/2022] Open
Abstract
Single-molecule microscopy has the potential to link repeatable discrete molecular behaviors to changes in cellular behavior. The approach used here finds characteristic changes in integrin density and mobility that are linked to local cellular protrusion. Mutants show that the density changes can be separated from mobility changes. Recent advances in light microscopy permit visualization of the behavior of individual molecules within dense macromolecular ensembles in live cells. It is now conceptually possible to relate the dynamic organization of molecular machinery to cellular function. However, inherent heterogeneities, as well as disparities between spatial and temporal scales, pose substantial challenges in deriving such a relationship. New approaches are required to link discrete single-molecule behavior with continuous cellular-level processes. Here we combined intercalated molecular and cellular imaging with a computational framework to detect reproducible transient changes in the behavior of individual molecules that are linked to cellular behaviors. Applying our approach to integrin transmembrane receptors revealed a spatial density gradient underlying characteristic molecular density increases and mobility decreases, indicating the subsequent onset of local protrusive activity. Integrin mutants further revealed that these density and mobility transients are separable and depend on different binding domains within the integrin cytoplasmic tail. Our approach provides a generalizable paradigm for dissecting dynamic spatiotemporal molecular behaviors linked to local cellular events.
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Affiliation(s)
- Khuloud Jaqaman
- Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390-8816
| | - James A Galbraith
- OHSU Center for Spatial Systems Biomedicine and Department of Biomedical Engineering, Portland, OR 97201-5042
| | - Michael W Davidson
- National High Magnet Field Laboratory, Florida State University, Tallahassee, FL 32310
| | - Catherine G Galbraith
- OHSU Center for Spatial Systems Biomedicine and Department of Biomedical Engineering, Portland, OR 97201-5042
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33
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Lu L, Lin C, Yan Z, Wang S, Zhang Y, Wang S, Wang J, Liu C, Chen J. Kindlin-3 Is Essential for the Resting α4β1 Integrin-mediated Firm Cell Adhesion under Shear Flow Conditions. J Biol Chem 2016; 291:10363-71. [PMID: 26994136 DOI: 10.1074/jbc.m116.717694] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 11/06/2022] Open
Abstract
Integrin-mediated rolling and firm cell adhesion are two critical steps in leukocyte trafficking. Integrin α4β1 mediates a mixture of rolling and firm cell adhesion on vascular cell adhesion molecule-1 (VCAM-1) when in its resting state but only supports firm cell adhesion upon activation. The transition from rolling to firm cell adhesion is controlled by integrin activation. Kindlin-3 has been shown to bind to integrin β tails and trigger integrin activation via inside-out signaling. However, the role of kindlin-3 in regulating resting α4β1-mediated cell adhesion is not well characterized. Herein we demonstrate that kindlin-3 was required for the resting α4β1-mediated firm cell adhesion but not rolling adhesion. Knockdown of kindlin-3 significantly decreased the binding of kindlin-3 to β1 and down-regulated the binding affinity of the resting α4β1 to soluble VCAM-1. Notably, it converted the resting α4β1-mediated firm cell adhesion to rolling adhesion on VCAM-1 substrates, increased cell rolling velocity, and impaired the stability of cell adhesion. By contrast, firm cell adhesion mediated by Mn(2+)-activated α4β1 was barely affected by knockdown of kindlin-3. Structurally, lack of kindlin-3 led to a more bent conformation of the resting α4β1. Thus, kindlin-3 plays an important role in maintaining a proper conformation of the resting α4β1 to mediate both rolling and firm cell adhesion. Defective kindlin-3 binding to the resting α4β1 leads to a transition from firm to rolling cell adhesion on VCAM-1, implying its potential role in regulating the transition between integrin-mediated rolling and firm cell adhesion.
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Affiliation(s)
- Ling Lu
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - ChangDong Lin
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - ZhanJun Yan
- The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Shu Wang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - YouHua Zhang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - ShiHui Wang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - JunLei Wang
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - Cui Liu
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
| | - JianFeng Chen
- From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and
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34
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de Guzman RC, Tsuda SM, Ton MTN, Zhang X, Esker AR, Van Dyke ME. Binding Interactions of Keratin-Based Hair Fiber Extract to Gold, Keratin, and BMP-2. PLoS One 2015; 10:e0137233. [PMID: 26317522 PMCID: PMC4552821 DOI: 10.1371/journal.pone.0137233] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/14/2015] [Indexed: 11/22/2022] Open
Abstract
Hair-derived keratin biomaterials composed mostly of reduced keratin proteins (kerateines) have demonstrated their utility as carriers of biologics and drugs for tissue engineering. Electrostatic forces between negatively-charged keratins and biologic macromolecules allow for effective drug retention; attraction to positively-charged growth factors like bone morphogenetic protein 2 (BMP-2) has been used as a strategy for osteoinduction. In this study, the intermolecular surface and bulk interaction properties of kerateines were investigated. Thiol-rich kerateines were chemisorbed onto gold substrates to form an irreversible 2-nm rigid layer for surface plasmon resonance analysis. Kerateine-to-kerateine cohesion was observed in pH-neutral water with an equilibrium dissociation constant (KD) of 1.8 × 10(-4) M, indicating that non-coulombic attractive forces (i.e. hydrophobic and van der Waals) were at work. The association of BMP-2 to kerateine was found to be greater (KD = 1.1 × 10(-7) M), within the range of specific binding. Addition of salts (phosphate-buffered saline; PBS) shortened the Debye length or the electrostatic field influence which weakened the kerateine-BMP-2 binding (KD = 3.2 × 10(-5) M). BMP-2 in bulk kerateine gels provided a limited release in PBS (~ 10% dissociation in 4 weeks), suggesting that electrostatic intermolecular attraction was significant to retain BMP-2 within the keratin matrix. Complete dissociation between kerateine and BMP-2 occurred when the PBS pH was lowered (to 4.5), below the keratin isoelectric point of 5.3. This phenomenon can be attributed to the protonation of keratin at a lower pH, leading to positive-positive repulsion. Therefore, the dynamics of kerateine-BMP-2 binding is highly dependent on pH and salt concentration, as well as on BMP-2 solubility at different pH and molarity. The study findings may contribute to our understanding of the release kinetics of drugs from keratin biomaterials and allow for the development of better, more clinically relevant BMP-2-conjugated systems for bone repair and regeneration.
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Affiliation(s)
- Roche C. de Guzman
- School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Shanel M. Tsuda
- School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Minh-Thi N. Ton
- School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Xiao Zhang
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Alan R. Esker
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Mark E. Van Dyke
- School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
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35
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Integration of actin dynamics and cell adhesion by a three-dimensional, mechanosensitive molecular clutch. Nat Cell Biol 2015; 17:955-63. [PMID: 26121555 DOI: 10.1038/ncb3191] [Citation(s) in RCA: 330] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 05/15/2015] [Indexed: 12/12/2022]
Abstract
During cell migration, the forces generated in the actin cytoskeleton are transmitted across transmembrane receptors to the extracellular matrix or other cells through a series of mechanosensitive, regulable protein-protein interactions termed the molecular clutch. In integrin-based focal adhesions, the proteins forming this linkage are organized into a conserved three-dimensional nano-architecture. Here we discuss how the physical interactions between the actin cytoskeleton and focal-adhesion-associated molecules mediate force transmission from the molecular clutch to the extracellular matrix.
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36
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Cross-Scale Integrin Regulation Organizes ECM and Tissue Topology. Dev Cell 2015; 34:33-44. [PMID: 26096733 DOI: 10.1016/j.devcel.2015.05.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 03/23/2015] [Accepted: 04/29/2015] [Indexed: 11/23/2022]
Abstract
The diverse morphologies of animal tissues are underlain by different configurations of adherent cells and extracellular matrix (ECM). Here, we elucidate a cross-scale mechanism for tissue assembly and ECM remodeling involving Cadherin 2, the ECM protein Fibronectin, and its receptor Integrin α5. Fluorescence cross-correlation spectroscopy within the zebrafish paraxial mesoderm mesenchyme reveals a physical association between Integrin α5 on adjacent cell membranes. This Integrin-Integrin complex correlates with conformationally inactive Integrin. Cadherin 2 stabilizes both the Integrin association and inactive Integrin conformation. Thus, Integrin repression within the adherent mesenchymal interior of the tissue biases Fibronectin fibrillogenesis to the tissue surface lacking cell-cell adhesions. Along nascent somite boundaries, Cadherin 2 levels decrease, becoming anti-correlated with levels of Integrin α5. Simultaneously, Integrin α5 clusters and adopts the active conformation and then commences ECM assembly. This cross-scale regulation of Integrin activation organizes a stereotypic pattern of ECM necessary for vertebrate body elongation and segmentation.
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37
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Liu J, Wang Z, Thinn AMM, Ma YQ, Zhu J. The dual structural roles of the membrane distal region of the α-integrin cytoplasmic tail during integrin inside-out activation. J Cell Sci 2015; 128:1718-31. [PMID: 25749862 DOI: 10.1242/jcs.160663] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 03/02/2015] [Indexed: 12/22/2022] Open
Abstract
Studies on the mechanism of integrin inside-out activation have been focused on the role of β-integrin cytoplasmic tails, which are relatively conserved and bear binding sites for the intracellular activators including talin and kindlin. Cytoplasmic tails for α-integrins share a conserved GFFKR motif at the membrane-proximal region and this forms a specific interface with the β-integrin membrane-proximal region to keep the integrin inactive. The α-integrin membrane-distal regions, after the GFFKR motif, are diverse both in length and sequence and their roles in integrin activation have not been well-defined. In this study, we report that the α-integrin cytoplasmic membrane-distal region contributes to maintaining integrin in the resting state and to integrin inside-out activation. Complete deletion of the α-integrin membrane-distal region diminished talin- and kindlin-mediated integrin ligand binding and conformational change. A proper length and suitable amino acids in α-integrin membrane-distal region was found to be important for integrin inside-out activation. Our data establish an essential role for the α-integrin cytoplasmic membrane-distal region in integrin activation and provide new insights into how talin and kindlin induce the high-affinity integrin conformation that is required for fully functional integrins.
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Affiliation(s)
- Jiafu Liu
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA
| | - Zhengli Wang
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA College of Marine Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China
| | - Aye Myat Myat Thinn
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Yan-Qing Ma
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jieqing Zhu
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226, USA Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Integrin αIIbβ3 transmembrane domain separation mediates bi-directional signaling across the plasma membrane. PLoS One 2015; 10:e0116208. [PMID: 25617834 PMCID: PMC4305291 DOI: 10.1371/journal.pone.0116208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/06/2014] [Indexed: 11/19/2022] Open
Abstract
Integrins play an essential role in hemostasis, thrombosis, and cell migration, and they transmit bidirectional signals. Transmembrane/cytoplasmic domains are hypothesized to associate in the resting integrins; whereas, ligand binding and intracellular activating signals induce transmembrane domain separation. However, how this conformational change affects integrin outside-in signaling and whether the α subunit cytoplasmic domain is important for this signaling remain elusive. Using Chinese Hamster Ovary (CHO) cells that stably expressed different integrin αIIbβ3 constructs, we discovered that an αIIb cytoplasmic domain truncation led to integrin activation but not defective outside-in signaling. In contrast, preventing transmembrane domain separation abolished both inside-out and outside-in signaling regardless of removing the αIIb cytoplasmic tail. Truncation of the αIIb cytoplasmic tail did not obviously affect adhesion-induced outside-in signaling. Our research revealed that transmembrane domain separation is a downstream conformational change after the cytoplasmic domain dissociation in inside-out activation and indispensable for ligand-induced outside-in signaling. The result implicates that the β TM helix rearrangement after dissociation is essential for integrin transmembrane signaling. Furthermore, we discovered that the PI3K/Akt pathway is not essential for cell spreading but spreading-induced Erk1/2 activation is PI3K dependent implicating requirement of the kinase for cell survival in outside-in signaling.
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Roll, adhere, spread and contract: structural mechanics of platelet function. Eur J Cell Biol 2015; 94:129-38. [PMID: 25655000 DOI: 10.1016/j.ejcb.2015.01.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 12/26/2014] [Accepted: 01/07/2015] [Indexed: 12/31/2022] Open
Abstract
Platelets are involved in life-sustaining processes such as hemostasis, wound healing, atherothrombosis and angiogenesis. Mechanical trauma to blood vessels causes platelet activation resulting in their adherence and clot formation at the damaged site, culminating in clot retraction and tissue repair. Two of the major players underlying this process are the cytoskeleton, i.e., actin and microtubules, and the membrane integrin receptors. Rare congenital bleeding disorders such as Glanzmann thrombasthenia and Bernard-Soulier syndrome are associated with genetic alterations of platelet surface receptors, also affecting the platelet cytoskeletal structure. In this review, we summarize the current knowledge about platelet structure and adhesion, and delve into the mechanical aspects of platelet function. Platelets lack a nucleus, and can thus provide a minimal model of a biological cell. New biophysical tools may help to scrutinize platelets anew and to extend the existing knowledge on cell biology.
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40
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Ellis SJ, Lostchuck E, Goult BT, Bouaouina M, Fairchild MJ, López-Ceballos P, Calderwood DA, Tanentzapf G. The talin head domain reinforces integrin-mediated adhesion by promoting adhesion complex stability and clustering. PLoS Genet 2014; 10:e1004756. [PMID: 25393120 PMCID: PMC4230843 DOI: 10.1371/journal.pgen.1004756] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 09/15/2014] [Indexed: 11/18/2022] Open
Abstract
Talin serves an essential function during integrin-mediated adhesion in linking integrins to actin via the intracellular adhesion complex. In addition, the N-terminal head domain of talin regulates the affinity of integrins for their ECM-ligands, a process known as inside-out activation. We previously showed that in Drosophila, mutating the integrin binding site in the talin head domain resulted in weakened adhesion to the ECM. Intriguingly, subsequent studies showed that canonical inside-out activation of integrin might not take place in flies. Consistent with this, a mutation in talin that specifically blocks its ability to activate mammalian integrins does not significantly impinge on talin function during fly development. Here, we describe results suggesting that the talin head domain reinforces and stabilizes the integrin adhesion complex by promoting integrin clustering distinct from its ability to support inside-out activation. Specifically, we show that an allele of talin containing a mutation that disrupts intramolecular interactions within the talin head attenuates the assembly and reinforcement of the integrin adhesion complex. Importantly, we provide evidence that this mutation blocks integrin clustering in vivo. We propose that the talin head domain is essential for regulating integrin avidity in Drosophila and that this is crucial for integrin-mediated adhesion during animal development. Cells are the building blocks of our bodies. How do cells rearrange to form three-dimensional body plans and maintain specific tissue structures? Specialized adhesion molecules on the cell surface mediate attachment between cells and their surrounding environment to hold tissues together. Our work uses the developing fruit fly embryo to demonstrate how such connections are regulated during tissue growth. Since the genes and molecules involved in this process are highly similar between flies and humans, we can also apply our findings to our understanding of how human tissues form and are maintained. We observe that, in late developing muscles, clusters of cell adhesion molecules concentrate together to create stronger attachments between muscle cells and tendon cells. This strengthening mechanism allows the fruit fly to accommodate increasing amounts of force imposed by larger, more active muscles. We identify specific genetic mutations that disrupt these strengthening mechanisms and lead to severe developmental defects during fly development. Our results illustrate how subtle fine-tuning of the connections between cells and their surrounding environment is important to form and maintain normal tissue structure across the animal kingdom.
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Affiliation(s)
- Stephanie J. Ellis
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Emily Lostchuck
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Benjamin T. Goult
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Mohamed Bouaouina
- Department of Pharmacology, Yale University, New Haven, Connecticut, United States of America
- Carnegie Mellon University Qatar, Education City, Doha, Qatar
| | - Michael J. Fairchild
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Pablo López-Ceballos
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - David A. Calderwood
- Department of Pharmacology, Yale University, New Haven, Connecticut, United States of America
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
- * E-mail:
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41
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Chigaev A, Smagley Y, Haynes MK, Ursu O, Bologa CG, Halip L, Oprea T, Waller A, Carter MB, Zhang Y, Wang W, Buranda T, Sklar LA. FRET detection of lymphocyte function-associated antigen-1 conformational extension. Mol Biol Cell 2014; 26:43-54. [PMID: 25378583 PMCID: PMC4279228 DOI: 10.1091/mbc.e14-06-1050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Lymphocyte function–associated antigen 1 (LFA-1) and its ligands are essential for immune cell interactions. LFA-1 is regulated through conformational changes. The relationship between molecular conformation and function is unclear. Förster resonance energy transfer is used to assess LFA-1 conformation under real-time signaling conditions. Lymphocyte function–associated antigen 1 (LFA-1, CD11a/CD18, αLβ2-integrin) and its ligands are essential for adhesion between T-cells and antigen-presenting cells, formation of the immunological synapse, and other immune cell interactions. LFA-1 function is regulated through conformational changes that include the modulation of ligand binding affinity and molecular extension. However, the relationship between molecular conformation and function is unclear. Here fluorescence resonance energy transfer (FRET) with new LFA-1–specific fluorescent probes showed that triggering of the pathway used for T-cell activation induced rapid unquenching of the FRET signal consistent with extension of the molecule. Analysis of the FRET quenching at rest revealed an unexpected result that can be interpreted as a previously unknown LFA-1 conformation.
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Affiliation(s)
| | | | - Mark K Haynes
- University of New Mexico Center for Molecular Discovery, and
| | - Oleg Ursu
- University of New Mexico Center for Molecular Discovery, and Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Cristian G Bologa
- University of New Mexico Center for Molecular Discovery, and Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Liliana Halip
- Department of Computational Chemistry, Institute of Chemistry, Romanian Academy, Timisoara 300223, Romania
| | - Tudor Oprea
- University of New Mexico Center for Molecular Discovery, and Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Anna Waller
- University of New Mexico Center for Molecular Discovery, and
| | - Mark B Carter
- University of New Mexico Center for Molecular Discovery, and
| | - Yinan Zhang
- Department of Pharmaceutical Science, College of Pharmacy, University of Kentucky, Lexington, KY 40506
| | - Wei Wang
- Department of Chemistry, University of New Mexico, Albuquerque, NM 87131
| | | | - Larry A Sklar
- Department of Pathology and Cancer Center, University of New Mexico Center for Molecular Discovery, and
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Müller MA, Brunie L, Bächer AS, Kessler H, Gottschalk KE, Reuning U. Cytoplasmic salt bridge formation in integrin αvß3 stabilizes its inactive state affecting integrin-mediated cell biological effects. Cell Signal 2014; 26:2493-503. [PMID: 25041847 DOI: 10.1016/j.cellsig.2014.07.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/09/2014] [Indexed: 02/01/2023]
Abstract
Heterodimeric integrin receptors are mediators of cell adhesion, motility, invasion, proliferation, and survival. By this, they are crucially involved in (tumor) cell biological behavior. Integrins trigger signals bidirectionally across cell membranes: by outside-in, following binding of protein ligands of the extracellular matrix, and by inside-out, where proteins are recruited to ß-integrin cytoplasmic tails resulting in conformational changes leading to increased integrin binding affinity and integrin activation. Computational modeling and experimental/mutational approaches imply that associations of integrin transmembrane domains stabilize the low-affinity integrin state. Moreover, a cytoplasmic interchain salt bridge is discussed to contribute to a tight clasp of the α/ß-membrane-proximal regions; however, its existence and physiological relevance for integrin activation are still a controversial issue. In order to further elucidate the functional role of salt bridge formation, we designed mutants of the tumor biologically relevant integrin αvß3 by mutually exchanging the salt bridge forming amino acid residues on each chain (αvR995D and ß3D723R). Following transfection of human ovarian cancer cells with different combinations of wild type and mutated integrin chains, we showed that loss of salt bridge formation strengthened αvß3-mediated adhesion to vitronectin, provoked recruitment of cytoskeletal proteins, such as talin, and induced integrin signaling, ultimately resulting in enhanced cell migration, proliferation, and activation of integrin-related signaling molecules. These data support the notion of a functional relevance of integrin cytoplasmic salt bridge disruption during integrin activation.
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Affiliation(s)
- Martina A Müller
- Clinical Research Unit, Dept. for Obstetrics & Gynecology, Technische Universitaet München, Munich, Germany
| | - Leonora Brunie
- Clinical Research Unit, Dept. for Obstetrics & Gynecology, Technische Universitaet München, Munich, Germany
| | - Anne-Sophie Bächer
- Clinical Research Unit, Dept. for Obstetrics & Gynecology, Technische Universitaet München, Munich, Germany
| | - Horst Kessler
- Institute for Advanced Study and Centre of Integrated Protein Science, Department Chemie, Technische Universitaet München, Garching, Germany; Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Ute Reuning
- Clinical Research Unit, Dept. for Obstetrics & Gynecology, Technische Universitaet München, Munich, Germany.
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43
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Platelet αIIbβ3 activation: filling in the pieces. Blood 2014; 123:3065-7. [PMID: 24832940 DOI: 10.1182/blood-2014-02-557355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this issue of Blood, Kasirer-Friede and colleagues show that the adhesion and degranulation promoter protein (ADAP) promotes αIIbβ3 activation by presenting the cytoplasmic proteins talin and kindlin to the β3 cytoplasmic tail.
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Li A, Guo Q, Kim C, Hu W, Ye F. Integrin αII b tail distal of GFFKR participates in inside-out αII b β3 activation. J Thromb Haemost 2014; 12:1145-55. [PMID: 24837519 PMCID: PMC4107134 DOI: 10.1111/jth.12610] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND Increases in ligand binding to integrins (activation) play critical roles in platelet and leukocyte function. Integrin activation requires talin and kindlin binding to integrin β cytoplasmic tails. Research has focused on the conserved GFFKR motif in integrin αII b tails, integrin β cytoplasmic tails and the binding partners of β tails. However, the roles of αII b tail distal of GFFKR motif are unexplored. OBJECTIVE To investigate the role of αII b tail distal of GFFKR in talin-mediated inside-out integrin signaling. METHODS We used model cell systems to examine the role of αII b tail distal of GFFKR in bidirectional αII b β3 signaling and αII b β3 -talin interactions. RESULTS Deletion of amino acid residues after the GFFKR motif in αII b tail moderately decreased β3 (D723R)-induced activation, abolished talin-induced αII b β3 activation in model cells, and inhibited agonist-induced αII b β3 activation in megakaryocytic cells. Furthermore, residues in αII b tail distal of GFFKR did not affect outside-in αII b β3 signaling or αII b β3 -talin interaction. Addition of non-homologous or non-specific amino acids to the GFFKR motif restored αII b β3 activation in model cells and in megakaryocytic cells. Molecular modeling indicates that β3 -bound talin sterically clashes with the αII b tail in the αII b β3 complexes, potentially disfavoring the α-β interactions that keep αII b β3 inactive. CONCLUSION The αII b tail sequences distal of GFFKR participate in talin-mediated inside-out αII b β3 activation through its steric clashes with β3 -bound talin.
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Affiliation(s)
- Ang Li
- Department of Hepatobiliary Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Qiang Guo
- Department of Hepatobiliary Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Chungho Kim
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Weiming Hu
- Department of Hepatobiliary Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Feng Ye
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093
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45
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Miller CG, Pozzi A, Zent R, Schwarzbauer JE. Effects of high glucose on integrin activity and fibronectin matrix assembly by mesangial cells. Mol Biol Cell 2014; 25:2342-50. [PMID: 24943838 PMCID: PMC4142608 DOI: 10.1091/mbc.e14-03-0800] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Aberrant accumulation of collagen IV defines diabetic nephropathy. It is shown here that high glucose increases fibronectin matrix assembly by activating integrin receptors on kidney cells. Collagen IV accumulation depends on this fibronectin matrix. Targeting fibronectin matrix may be a useful therapy to stem matrix accumulation in the diabetic kidney. The filtration unit of the kidney is the glomerulus, a capillary network supported by mesangial cells and extracellular matrix (ECM). Glomerular function is compromised in diabetic nephropathy (DN) by uncontrolled buildup of ECM, especially type IV collagen, which progressively occludes the capillaries. Increased levels of the ECM protein fibronectin (FN) are also present; however, its role in DN is unknown. Mesangial cells cultured under high glucose conditions provide a model system for studying the effect of elevated glucose on deposition of FN and collagen IV. Imaging of mesangial cell cultures and analysis of detergent-insoluble matrix show that, under high glucose conditions, mesangial cells assembled significantly more FN matrix, independent of FN protein levels. High glucose conditions induced protein kinase C–dependent β1 integrin activation, and FN assembly in normal glucose was increased by stimulation of integrin activity with Mn2+. Collagen IV incorporation into the matrix was also increased under high glucose conditions and colocalized with FN fibrils. An inhibitor of FN matrix assembly prevented collagen IV deposition, demonstrating dependence of collagen IV on FN matrix. We conclude that high glucose induces FN assembly, which contributes to collagen IV accumulation. Enhanced assembly of FN might facilitate dysregulated ECM accumulation in DN.
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Affiliation(s)
- Charles G Miller
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Ambra Pozzi
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232Department of Medicine, Veterans Affairs Medical Center, Nashville, TN 37212
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232Department of Medicine, Veterans Affairs Medical Center, Nashville, TN 37212Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232
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46
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Cheng M, Li J, Negri A, Coller BS. Swing-out of the β3 hybrid domain is required for αIIbβ3 priming and normal cytoskeletal reorganization, but not adhesion to immobilized fibrinogen. PLoS One 2013; 8:e81609. [PMID: 24349096 PMCID: PMC3857192 DOI: 10.1371/journal.pone.0081609] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 10/15/2013] [Indexed: 12/24/2022] Open
Abstract
Structural and functional analyses of integrin αIIbβ3 has implicated swing-out motion of the β3 hybrid domain in αIIbβ3 activation and ligand binding. Using data from targeted molecular dynamics (TMD) simulations, we engineered two disulfide-bonded mutant receptors designed to limit swing-out (XS-O). XS-O mutants cannot bind the high Mr ligand fibrinogen in the presence of an activating mAb or after introducing mutations into the αIIb subunit designed to simulate inside-out signaling. They also have reduced capacity to be “primed” to bind fibrinogen by pretreatment with eptifibatide. They can, however, bind the small RGD venom protein kistrin. Despite their inability to bind soluble fibrinogen, the XS-O mutants can support adhesion to immobilized fibrinogen, although such adhesion does not initiate outside-in signaling leading to normal cytoskeletal reorganization. Collectively, our data further define the biologic role of β3 hybrid domain swing-out in both soluble and immobilized high Mr ligand binding, as well as in priming and outside-in signaling. We also infer that swing-out is likely to be a downstream effect of receptor extension.
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Affiliation(s)
- Ming Cheng
- Allen and Frances Adler Laboratory of Blood and Vascular Biology, The Rockefeller University, New York, New York, United States of America
| | - Jihong Li
- Allen and Frances Adler Laboratory of Blood and Vascular Biology, The Rockefeller University, New York, New York, United States of America
| | - Ana Negri
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Barry S. Coller
- Allen and Frances Adler Laboratory of Blood and Vascular Biology, The Rockefeller University, New York, New York, United States of America
- * E-mail:
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47
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Gkourogianni A, Egot M, Koloka V, Moussis V, Tsikaris V, Panou-Pomonis E, Sakarellos-Daitsiotis M, Bachelot-Loza C, Tsoukatos DC. Palmitoylated peptide, being derived from the carboxyl-terminal sequence of the integrin αIIbcytoplasmic domain, inhibits talin binding to αIIbβ3. Platelets 2013; 25:619-27. [DOI: 10.3109/09537104.2013.850588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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48
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Kalli AC, Campbell ID, Sansom MSP. Conformational changes in talin on binding to anionic phospholipid membranes facilitate signaling by integrin transmembrane helices. PLoS Comput Biol 2013; 9:e1003316. [PMID: 24204243 PMCID: PMC3814715 DOI: 10.1371/journal.pcbi.1003316] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 09/19/2013] [Indexed: 01/01/2023] Open
Abstract
Integrins are heterodimeric (αβ) cell surface receptors that are activated to a high affinity state by the formation of a complex involving the α/β integrin transmembrane helix dimer, the head domain of talin (a cytoplasmic protein that links integrins to actin), and the membrane. The talin head domain contains four sub-domains (F0, F1, F2 and F3) with a long cationic loop inserted in the F1 domain. Here, we model the binding and interactions of the complete talin head domain with a phospholipid bilayer, using multiscale molecular dynamics simulations. The role of the inserted F1 loop, which is missing from the crystal structure of the talin head, PDB:3IVF, is explored. The results show that the talin head domain binds to the membrane predominantly via cationic regions on the F2 and F3 subdomains and the F1 loop. Upon binding, the intact talin head adopts a novel V-shaped conformation which optimizes its interactions with the membrane. Simulations of the complex of talin with the integrin α/β TM helix dimer in a membrane, show how this complex promotes a rearrangement, and eventual dissociation of, the integrin α and β transmembrane helices. A model for the talin-mediated integrin activation is proposed which describes how the mutual interplay of interactions between transmembrane helices, the cytoplasmic talin protein, and the lipid bilayer promotes integrin inside-out activation. Transmission of signals across the cell membrane is an essential process for all living organisms. Integrins are one example of cell surface receptors (αβ) which, uniquely, form a bidirectional signalling pathway across the membrane. Integrins are crucial for many cellular processes and play key roles in pathological defects such as cardiovascular diseases and cancer. They are activated to a high affinity state by the intracellular protein talin in a process known as ‘inside-out activation’. Despite their importance and the existence of functional and structural data, the mechanism by which talin activates integrin remains elusive. In this study we use a multi-scale computational approach, which combines coarse-grained and atomistic molecular dynamics simulations, to suggest how the formation of the complex between the talin head domain, the cell membrane and the integrin moves the integrin equilibrium towards an active state. Our results show that conformational changes within the talin head domains optimize its interactions with the cell membrane. Upon binding to the integrin, talin facilitates rearrangement of the integrin TM region thus promoting integrin activation. This study also provides a demonstration of the strengths of a computational multi-scale approach in studies of membrane interactions and receptor conformational changes and associated proteins that enable transmembrane signaling.
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Affiliation(s)
- Antreas C. Kalli
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Iain D. Campbell
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- * E-mail:
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49
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Surya W, Li Y, Millet O, Diercks T, Torres J. Transmembrane and Juxtamembrane Structure of αL Integrin in Bicelles. PLoS One 2013; 8:e74281. [PMID: 24069290 PMCID: PMC3771934 DOI: 10.1371/journal.pone.0074281] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/30/2013] [Indexed: 12/28/2022] Open
Abstract
The accepted model for the interaction of α and β integrins in the transmembrane (TM) domain is based on the pair αIIbβ3. This involves the so-called outer and inner membrane association clasps (OMC and IMC, respectively). In the α chain, the OMC involves a GxxxG-like motif, whereas in the IMC a conserved juxtamembrane GFFKR motif experiences a backbone reversal that partially fills the void generated by TM separation towards the cytoplasmic half. However, the GFFKR motif of several α integrin cytoplasmic tails in non-bicelle environments has been shown to adopt an α-helical structure that is not membrane-embedded and which was shown to bind a variety of cytoplasmic proteins. Thus it is not known if a membrane-embedded backbone reversal is a conserved structural feature in α integrins. We have studied the system αLβ2 because of its importance in leukocytes, where integrin deactivation is particularly important. Herein we show that the backbone reversal feature is not only present in αIIb but also in αL-TM when reconstituted in bicelles. Additionally, titration with β2 TM showed eight residues clustering along one side of αL-TM, forming a plausible interacting face with β2. The latter orientation is consistent with a previously predicted reported polar interaction between αL Ser-1071 and β2 Thr-686.
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Affiliation(s)
- Wahyu Surya
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yan Li
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Oscar Millet
- Structural Biology Unit, CIC BioGUNE, Derio Vizcaya, Spain
| | - Tammo Diercks
- Structural Biology Unit, CIC BioGUNE, Derio Vizcaya, Spain
| | - Jaume Torres
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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50
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Abstract
Metastasis is a combination of biological events that makes the difference between cancer and other diseases. Metastasis requires flow of erroneous but precisely coordinated basic cellular activities like cell migration-invasion, cell survival-apoptosis, cell proliferation, etc. All of these processes require efficient regulation of cell attachment and detachment, which recruit integrin receptors in this flow of events. World literatures show several aspects of interrelation of integrins and metastasis. Integrin molecules are being used as prime target to battle metastasis. In this review we are collating the observations showing importance of integrin biology in regulation of metastasis and the strategies where integrin receptors are being used as targets to regulate metastasis.
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Affiliation(s)
- Kirat Kumar Ganguly
- Department of Receptor Biology & Tumor Metastasis, Chittaranjan National Cancer Institute, Kolkata, India
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