1
|
Drisaldi B, Colnaghi L, Levine A, Huang Y, Snyder AM, Metzger DJ, Theis M, Kandel DB, Kandel ER, Fioriti L. Cytoplasmic Polyadenylation Element Binding Proteins CPEB1 and CPEB3 Regulate the Translation of FosB and Are Required for Maintaining Addiction-Like Behaviors Induced by Cocaine. Front Cell Neurosci 2020; 14:207. [PMID: 32742260 PMCID: PMC7365288 DOI: 10.3389/fncel.2020.00207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/11/2020] [Indexed: 11/13/2022] Open
Abstract
A recurrent and devastating feature of addiction to a drug of abuse is its persistence, which is mediated by maladaptive long-term memories of the highly pleasurable experience initially associated with the consumption of the drug. We have recently found that members of the CPEB family of proteins (Cytoplasmic Polyadenylation Element-Binding Proteins) are involved in the maintenance of spatial memory. However, their possible role in the maintenance of memories that sustain addictive behavior has yet to be explored. Little is known about any of the mechanisms for maintaining memories for addictive behavior. To address the mechanisms whereby addictive behavior is maintained over time, we utilized a conditional transgenic mouse model expressing a dominant-negative version of CPEB1 that abolishes the activity in the forebrain of two of the four CPEB isoforms (CPEB1 and CPEB3). We found that, following cocaine administration, these dominant-negative (DN) CPEB mice showed a significant decrease, when compared to wild type (WT) mice, in both locomotor sensitizations and conditioned place preference (CPP), two indices of addictive behavior. Supporting these behavioral results, we also found a difference between WT and DN-CPEB1-3 mice in the cocaine-induced synaptic depression in the core of the Nucleus Accumbens (NAc). Finally, we found that (1) CPEB is reduced in transgenic mice following cocaine injections and that (2) FosB, known for its contribution to establishing the addictive phenotype, when its expression in the striatum is increased by drug administration, is a novel target of CPEBs molecules. Thus, our study highlights how CPEB1 and CPEB3 act on target mRNAs to build the neuroadaptative implicit memory responses that lead to the development of the cocaine addictive phenotypes in mammals.
Collapse
Affiliation(s)
- Bettina Drisaldi
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Luca Colnaghi
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Amir Levine
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - YanYou Huang
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Anna M Snyder
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Daniel J Metzger
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Martin Theis
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Denise B Kandel
- Mailman School of Public Health, Columbia University, New York, NY, United States.,Department of Epidemiology of Substance Abuse, New York State Psychiatric Institute, New York, NY, United States
| | - Eric R Kandel
- Department of Neuroscience, Columbia University, New York, NY, United States.,Kavli Institute for Brain Science, Columbia University, New York, NY, United States.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States.,Howard Hughes Medical Institute, Chevy Chase, MD, United States
| | - Luana Fioriti
- Department of Neuroscience, Columbia University, New York, NY, United States.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States.,Dulbecco Telethon Institute, Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| |
Collapse
|
2
|
Fabbro A, Bencivenni M, Piasentier E, Sforza S, Stecchini ML, Lippe G. Proteolytic resistance of actin but not of myosin heavy chain during processing of Italian PDO (protected designation of origin) dry-cured hams. Eur Food Res Technol 2015. [DOI: 10.1007/s00217-015-2594-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
3
|
Lemieux MG, Janzen D, Hwang R, Roldan J, Jarchum I, Knecht DA. Visualization of the actin cytoskeleton: different F-actin-binding probes tell different stories. Cytoskeleton (Hoboken) 2013; 71:157-69. [PMID: 24347465 DOI: 10.1002/cm.21160] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/31/2013] [Accepted: 12/10/2013] [Indexed: 02/06/2023]
Abstract
The actin cytoskeleton is necessary for cell viability and plays crucial roles in cell motility, endocytosis, growth, and cytokinesis. Hence visualization of dynamic changes in F-actin distribution in vivo is of central importance in cell biology. This has been accomplished by the development of fluorescent protein fusions to actin itself or to various actin-binding proteins, actin cross-linking proteins, and their respective actin-binding domains (ABDs). Although these protein fusions have been shown to bind to F-actin in vivo, we show that the fluorescent protein used for visualization changes the subset of F-actin labeled by an F-actin ABD probe. Further, different amino acid linkers between the fluorescent protein and ABD induced a similar change in localization. Although different linkers and fluorescent proteins can alter the subset of actin bound by a particular ABD, in most cases, the fusion protein did not label all of a cell's F-actin all of the time. Even LimEΔcoil and GFP-actin, which have been used extensively for cytoskeletal visualization, were highly variable in the subsets of actin that they labeled. Lifeact, conversely, clearly labeled cortical F-actin as well as F-actin in the anterior pseudopods of motile cells and in macropinocytotic cups. We conclude that Lifeact most accurately labels F-actin and is the best currently available probe for visualization of dynamic changes in F-actin networks.
Collapse
Affiliation(s)
- Michael G Lemieux
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, 06269
| | | | | | | | | | | |
Collapse
|
4
|
Gallo G. Mechanisms underlying the initiation and dynamics of neuronal filopodia: from neurite formation to synaptogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 301:95-156. [PMID: 23317818 DOI: 10.1016/b978-0-12-407704-1.00003-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Filopodia are finger-like cellular protrusions found throughout the metazoan kingdom and perform fundamental cellular functions during development and cell migration. Neurons exhibit a wide variety of extremely complex morphologies. In the nervous system, filopodia underlie many major morphogenetic events. Filopodia have roles spanning the initiation and guidance of neuronal processes, axons and dendrites to the formation of synaptic connections. This chapter addresses the mechanisms of the formation and dynamics of neuronal filopodia. Some of the major lessons learned from the study of neuronal filopodia are (1) there are multiple mechanisms that can regulate filopodia in a context-dependent manner, (2) that filopodia are specialized subcellular domains, (3) that filopodia exhibit dynamic membrane recycling which also controls aspects of filopodial dynamics, (4) that neuronal filopodia contain machinery for the orchestration of the actin and microtubule cytoskeleton, and (5) localized protein synthesis contributes to neuronal filopodial dynamics.
Collapse
Affiliation(s)
- Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair and Rehabilitation, Department of Anatomy and Cell Biology, Temple University, Philadelphia, PA, USA.
| |
Collapse
|
5
|
Sörensen PM, Iacob RE, Fritzsche M, Engen JR, Brieher WM, Charras G, Eggert US. The natural product cucurbitacin E inhibits depolymerization of actin filaments. ACS Chem Biol 2012; 7:1502-8. [PMID: 22724897 DOI: 10.1021/cb300254s] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Although small molecule actin modulators have been widely used as research tools, only one cell-permeable small molecule inhibitor of actin depolymerization (jasplakinolide) is commercially available. We report that the natural product cucurbitacin E inhibits actin depolymerization and show that its mechanism of action is different from jasplakinolide. In assays using pure fluorescently labeled actin, cucurbitacin E specifically affects depolymerization without affecting polymerization. It inhibits actin depolymerization at substoichiometric concentrations up to 1:6 cucurbitacin E:actin. Cucurbitacin E specifically binds to filamentous actin (F-actin) forming a covalent bond at residue Cys257, but not to monomeric actin (G-actin). On the basis of its compatibility with phalloidin staining, we show that cucurbitacin E occupies a different binding site on actin filaments. Using loss of fluorescence after localized photoactivation, we found that cucurbitacin E inhibits actin depolymerization in live cells. Cucurbitacin E is a widely available plant-derived natural product, making it a useful tool to study actin dynamics in cells and actin-based processes such as cytokinesis.
Collapse
Affiliation(s)
- Pia M. Sörensen
- Dana-Farber Cancer Institute and Department of Biological Chemistry
and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States
| | - Roxana E. Iacob
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, United
States
| | - Marco Fritzsche
- London Centre for
Nanotechnology and Department of Physics and Astronomy, University College London, London, U.K
| | - John R. Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, United
States
| | - William M. Brieher
- Department of Cell and Developmental
Biology, University of Illinois, Urbana−Champaign,
Illinois, United States
| | - Guillaume Charras
- London Centre for Nanotechnology and Department of Cell and Developmental
Biology, University College London, London,
U.K
| | - Ulrike S. Eggert
- Dana-Farber Cancer Institute and Department of Biological Chemistry
and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States
- Department of Chemistry and Randall Division of Cell and Molecular Biophysics King’s College London, London, U.K
| |
Collapse
|
6
|
Broderick MJF, Bobkov A, Winder SJ. Utrophin ABD binds to F-actin in an open conformation. FEBS Open Bio 2012; 2:6-11. [PMID: 23650574 PMCID: PMC3642092 DOI: 10.1016/j.fob.2012.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 01/18/2012] [Indexed: 11/20/2022] Open
Abstract
Structural analyses of actin binding regions comprising tandem calponin homology domains alone and when bound to F-actin have revealed a number of different conformations with calponin homology domains in ‘open’ and ‘closed’ positions. In an attempt to resolve these issues we have examined the properties of the utrophin actin binding domain in open and closed conformations in order to verify the conformation when bound to F-actin. Locking the actin binding domain in a closed conformation using engineered cysteine residues in each calponin homology domain reduced the affinity for F-actin without affecting the stoichiometry furthermore differential scanning calorimetry experiments revealed a reduction in melting temperature on binding to actin. The data suggest the amino-terminal utrophin actin binding domain is in an open conformation in solution and when bound to F-actin.
Collapse
Key Words
- ABD, actin binding domain
- Actin binding domain
- CD, circular dichroism
- CH, calponin homology
- Calponin homology domain
- DSC, differential scanning calorimetry
- Differential scanning calorimetry
- Dystrophin
- EM, electron microscopy
- F-actin, filamentous actin
- NTCB, 2-nitro-5-thiocyanobenzoic acid
- SDS-PAGE, sodium dodecyl sulphate poly-acrylamide electrophoresis
- Spectrin
- Tm, melting temperature
- UTR261, utrophin residues 1-261
- α-Actinin
Collapse
Affiliation(s)
- Mike J F Broderick
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK ; IBLS, University of Glasgow, Glasgow G12 8QQ, UK
| | | | | |
Collapse
|
7
|
Paternoster L, Standl M, Chen CM, Ramasamy A, Bønnelykke K, Duijts L, Ferreira MA, Alves AC, Thyssen JP, Albrecht E, Baurecht H, Feenstra B, Sleiman PMA, Hysi P, Warrington NM, Curjuric I, Myhre R, Curtin JA, Groen-Blokhuis MM, Kerkhof M, Sääf A, Franke A, Ellinghaus D, Fölster-Holst R, Dermitzakis E, Montgomery SB, Prokisch H, Heim K, Hartikainen AL, Pouta A, Pekkanen J, Blakemore AIF, Buxton JL, Kaakinen M, Duffy DL, Madden PA, Heath AC, Montgomery GW, Thompson PJ, Matheson MC, Le Souëf P, Pourcain BS, Smith GD, Henderson J, Kemp JP, Timpson NJ, Deloukas P, Ring SM, Wichmann HE, Müller-Nurasyid M, Novak N, Klopp N, Rodríguez E, McArdle W, Linneberg A, Menné T, Nohr EA, Hofman A, Uitterlinden AG, van Duijn CM, Rivadeneira F, de Jongste JC, van der Valk RJP, Wjst M, Jogi R, Geller F, Boyd HA, Murray JC, Kim C, Mentch F, March M, Mangino M, Spector TD, Bataille V, Pennell CE, Holt PG, Sly P, Tiesler CMT, Thiering E, Illig T, Imboden M, Nystad W, Simpson A, Hottenga JJ, Postma D, Koppelman GH, Smit HA, Söderhäll C, Chawes B, Kreiner-Møller E, Bisgaard H, Melén E, Boomsma DI, Custovic A, Jacobsson B, Probst-Hensch NM, Palmer LJ, Glass D, Hakonarson H, Melbye M, Jarvis DL, Jaddoe VWV, Gieger C, Strachan DP, Martin NG, Jarvelin MR, Heinrich J, Evans DM, Weidinger S. Meta-analysis of genome-wide association studies identifies three new risk loci for atopic dermatitis. Nat Genet 2011; 44:187-92. [PMID: 22197932 PMCID: PMC3272375 DOI: 10.1038/ng.1017] [Citation(s) in RCA: 256] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 11/01/2011] [Indexed: 02/07/2023]
Abstract
Atopic dermatitis (AD) is a commonly occurring chronic skin disease with high heritability. Apart from filaggrin (FLG), the genes influencing atopic dermatitis are largely unknown. We conducted a genome-wide association meta-analysis of 5,606 affected individuals and 20,565 controls from 16 population-based cohorts and then examined the ten most strongly associated new susceptibility loci in an additional 5,419 affected individuals and 19,833 controls from 14 studies. Three SNPs reached genome-wide significance in the discovery and replication cohorts combined, including rs479844 upstream of OVOL1 (odds ratio (OR) = 0.88, P = 1.1 × 10(-13)) and rs2164983 near ACTL9 (OR = 1.16, P = 7.1 × 10(-9)), both of which are near genes that have been implicated in epidermal proliferation and differentiation, as well as rs2897442 in KIF3A within the cytokine cluster at 5q31.1 (OR = 1.11, P = 3.8 × 10(-8)). We also replicated association with the FLG locus and with two recently identified association signals at 11q13.5 (rs7927894; P = 0.008) and 20q13.33 (rs6010620; P = 0.002). Our results underline the importance of both epidermal barrier function and immune dysregulation in atopic dermatitis pathogenesis.
Collapse
Affiliation(s)
- Lavinia Paternoster
- MRC CAiTE centre, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Marie Standl
- Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Chih-Mei Chen
- Hannover Medical School, Department for Paediatric Pneumology, Allergy and Neonatology, Hannover, Germany
| | - Adaikalavan Ramasamy
- Respiratory Epidemiology and Public Health, Imperial College London, United Kingdom
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, United Kingdom
- Department of Medical and Molecular Genetics, Kings College London, Guy’s Hospital, London, United Kingdom
| | - Klaus Bønnelykke
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood; Health Sciences, University of Copenhagen & Copenhagen University Hospital, Gentofte, Denmark
| | - Liesbeth Duijts
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Division of Respiratory Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Alexessander Couto Alves
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, United Kingdom
| | - Jacob P Thyssen
- National Allergy Research Centre, Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen, Denmark
| | - Eva Albrecht
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Hansjörg Baurecht
- Department of Dermatology and Allergy, Technische Universität München, Munich, Germany
- ZAUM-Center for Allergy and Environment, Helmholtz-Zentrum and Technische Universität, Munich, Germany
- Graduate School of Information Science in Health, Technische Universität München, Munich, Germany
| | - Bjarke Feenstra
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Patrick MA Sleiman
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Pirro Hysi
- Department of Twin Research and Genetic Epidemiology, King’s College London
| | - Nicole M Warrington
- School of Women’s and Infants’ Health, The University of Western Australia, Western Australia, Australia
| | - Ivan Curjuric
- Swiss Tropical and Public Health Institute (SwissTPH), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ronny Myhre
- Norwegian Institute of Public Health, Department of Genes and Environment, Division of Epidemiology, Oslo, Norway
| | - John A Curtin
- The University of Manchester, Manchester Academic Health Science Centre, NIHR Translational Research Facility in Respiratory Medicine, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK
| | | | - Marjan Kerkhof
- Department of Pediatric Pulmonology and Allergology, University Medical Center Groningen, University of Groningen, GRIAC research institute, Groningen, The Netherlands
| | - Annika Sääf
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - David Ellinghaus
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Regina Fölster-Holst
- Department of Dermatology, Allergology, and Venerology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Emmanouil Dermitzakis
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, 1211 Switzerland
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Stephen B Montgomery
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, 1211 Switzerland
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Holger Prokisch
- Institute of Human Genetics, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Katharina Heim
- Institute of Human Genetics, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | | | - Anneli Pouta
- Department of Obstetrics and Gynaecology, University of Oulu
- Department of Children, Young People and Families, National Institute for Health and Welfare, Finland
| | - Juha Pekkanen
- Department of Environmental Health, National Institute for Health and Welfare (THL), Kuopio, Finland
| | | | | | - Marika Kaakinen
- Institute of Health Sciences, University of Oulu, Oulu, Finland Biocenter Oulu, University of Oulu, Oulu, Finland
| | - David L Duffy
- Queensland Institute of Medical Research, Brisbane, Australia
| | - Pamela A Madden
- Washington University School of Medicine, St Louis, United States
| | - Andrew C Heath
- Washington University School of Medicine, St Louis, United States
| | | | - Philip J Thompson
- Lung Institute of Western Australia (WA) and Centre for Asthma, Allergy and Respiratory Research, University of WA, Perth, Australia
| | - Melanie C Matheson
- Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Melbourne, Australia
| | - Peter Le Souëf
- School of Paediatrics and Child Health, Princess Margaret Hospital for Children, Perth, Australia
| | - AAGC collaborators
- Australian Asthma Genetics Consortium, a full list of collaborators is included in the Supplementary Note
| | - Beate St Pourcain
- The School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - George Davey Smith
- MRC CAiTE centre, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - John Henderson
- The School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - John P Kemp
- MRC CAiTE centre, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Nicholas J Timpson
- MRC CAiTE centre, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Panos Deloukas
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Susan M Ring
- The School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - H-Erich Wichmann
- Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Medical Informatics, Biometry and Epidemiology, Chair of Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Klinikum Grosshadern, Munich, Germany
| | - Martina Müller-Nurasyid
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Medical Informatics, Biometry and Epidemiology, Chair of Epidemiology and Chair of Genetic Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Department of Medicine I, University Hospital Grosshadern, Ludwig-Maximilians-Universität, Munich, Germany
| | - Natalija Novak
- Department of Dermatology and Allergy, University of Bonn Medical Center, Bonn, Germany
| | - Norman Klopp
- Unit for Molecular Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Elke Rodríguez
- Department of Dermatology and Allergy, Technische Universität München, Munich, Germany
- ZAUM-Center for Allergy and Environment, Helmholtz-Zentrum and Technische Universität, Munich, Germany
| | - Wendy McArdle
- University of Bristol, ALSPAC Laboratory, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Allan Linneberg
- Research Center for Prevention and Health, Glostrup University Hospital, Denmark
| | - Torkil Menné
- National Allergy Research Centre, Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen, Denmark
| | - Ellen A Nohr
- Institute of Public Health, Aarhus University, Denmark
| | - Albert Hofman
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - André G Uitterlinden
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Fernando Rivadeneira
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Johan C de Jongste
- Department of Pediatrics, Division of Respiratory Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ralf JP van der Valk
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Division of Respiratory Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Matthias Wjst
- Comprehensive Pneumology Center and Institute of Lung Biology and Disease, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Rain Jogi
- Lung Clinic, Tartu University, Tartu, Estonia
| | - Frank Geller
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Heather A Boyd
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | | | - Cecilia Kim
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Frank Mentch
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michael March
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Massimo Mangino
- Department of Twin Research and Genetic Epidemiology, King’s College London
| | - Tim D Spector
- Department of Twin Research and Genetic Epidemiology, King’s College London
| | - Veronique Bataille
- Department of Twin Research and Genetic Epidemiology, King’s College London
| | - Craig E Pennell
- School of Women’s and Infants’ Health, The University of Western Australia, Western Australia, Australia
| | - Patrick G Holt
- Telethon Institute for Child Health Research and Centre for Child Health Research, The University of Western Australia, Western Australia, Australia
| | - Peter Sly
- Queensland Children’s Medical Research Institute; University of Queensland; WHO Collaborating Centre for Research on Children’s Environmental Health, Queensland, Australia
| | - Carla MT Tiesler
- Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
- Division of Metabolic Diseases and Nutritional Medicine, Dr von Hauner Children’s Hospital, Ludwig-Maximilians University Munich, Munich, Germany
| | - Elisabeth Thiering
- Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Thomas Illig
- Unit for Molecular Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Medea Imboden
- Swiss Tropical and Public Health Institute (SwissTPH), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Wenche Nystad
- Norwegian Institute of Public Health, Division of Epidemiology, Oslo, Norway
| | - Angela Simpson
- The University of Manchester, Manchester Academic Health Science Centre, NIHR Translational Research Facility in Respiratory Medicine, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK
| | - Jouke-Jan Hottenga
- Department of Biological Psychology, VU University, Amsterdam, The Netherlands
| | - Dirkje Postma
- Department of Pulmonology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gerard H Koppelman
- Dpt of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children ’s Hospital, GRIAC research institute, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Henriette A Smit
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
| | - Cilla Söderhäll
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Bo Chawes
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood; Health Sciences, University of Copenhagen & Copenhagen University Hospital, Gentofte, Denmark
| | - Eskil Kreiner-Møller
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood; Health Sciences, University of Copenhagen & Copenhagen University Hospital, Gentofte, Denmark
| | - Hans Bisgaard
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood; Health Sciences, University of Copenhagen & Copenhagen University Hospital, Gentofte, Denmark
| | - Erik Melén
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Astrid Lindgren Children’s Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Dorret I Boomsma
- Department of Biological Psychology, VU University, Amsterdam, The Netherlands
| | - Adnan Custovic
- The University of Manchester, Manchester Academic Health Science Centre, NIHR Translational Research Facility in Respiratory Medicine, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK
| | - Bo Jacobsson
- Norwegian Institute of Public Health, Department of Genes and Environment, Division of Epidemiology, Oslo, Norway
- Department of Obstetrics and Gynecology, Sahlgrenska University Hospital, Sahlgrenska Academy, Göteborg University, Sweden
| | - Nicole M Probst-Hensch
- Swiss Tropical and Public Health Institute (SwissTPH), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Lyle J Palmer
- Ontario Institute for Cancer Research, Toronto; University of Toronto, Toronto, Canada
| | - Daniel Glass
- Department of Twin Research and Genetic Epidemiology, King’s College London
| | - Hakon Hakonarson
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatric, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Mads Melbye
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Deborah L Jarvis
- Respiratory Epidemiology and Public Health, Imperial College London, United Kingdom
| | - Vincent WV Jaddoe
- The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Christian Gieger
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - The GOYA consortium
- The Genetics of Overweight Young Adults consortium, list of members in Supplementary Note
| | - David P Strachan
- Division of Population Health Sciences and Education, St George’s, University of London, London, UK
| | | | - Marjo-Riitta Jarvelin
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, United Kingdom
- Institute of Health Sciences, Biocenter, University of Oulu, Finland
- National Institute of Health and Welfare, Finland
| | - Joachim Heinrich
- Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - David M Evans
- MRC CAiTE centre, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Stephan Weidinger
- Department of Dermatology, Allergology, and Venerology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
8
|
Quadri SK. Cross talk between focal adhesion kinase and cadherins: role in regulating endothelial barrier function. Microvasc Res 2011; 83:3-11. [PMID: 21864544 DOI: 10.1016/j.mvr.2011.08.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 07/26/2011] [Accepted: 08/02/2011] [Indexed: 01/11/2023]
Abstract
A layer of endothelial cells attached to their underlying matrices by complex transmembrane structures termed focal adhesion (FA) proteins maintains the barrier property of microvascular endothelium. FAs sense the physical properties of the extracellular matrix (ECM) and organize the cytoskeleton accordingly. The close association of adherens junction (AJ) protein, cadherin, with the cytoskeleton is known to be essential in coordinating the appropriate mechanical properties to cell-cell contacts. Recently, it has become clear that a crosstalk exists between focal adhesion kinase (FAK) and cadherin that regulates signaling at intercellular endothelial junctions. This review discusses recent advances in our understanding of the dynamic regulation of the molecular connections between FAK and the cadherin complex and cadherin-catenin-actin interaction-dependent changes as well as the role of small GTPases in endothelial barrier regulation. This review also discusses how a signaling network regulates a range of cellular processes important for barrier function and diseases.
Collapse
Affiliation(s)
- Sadiqa K Quadri
- Lung Biology Laboratory, Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
| |
Collapse
|
9
|
Vogel S, Wottawa M, Farhat K, Zieseniss A, Schnelle M, Le-Huu S, von Ahlen M, Malz C, Camenisch G, Katschinski DM. Prolyl hydroxylase domain (PHD) 2 affects cell migration and F-actin formation via RhoA/rho-associated kinase-dependent cofilin phosphorylation. J Biol Chem 2010; 285:33756-63. [PMID: 20801873 DOI: 10.1074/jbc.m110.132985] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cells are responding to hypoxia via prolyl-4-hydroxylase domain (PHD) enzymes, which are responsible for oxygen-dependent hydroxylation of the hypoxia-inducible factor (HIF)-1α subunit. To gain further insight into PHD function, we generated knockdown cell models for the PHD2 isoform, which is the main isoform regulating HIF-1α hydroxylation and thus stability in normoxia. Induction of a PHD2 knockdown in tetracycline-inducible HeLa PHD2 knockdown cells resulted in increased F-actin formation as detected by phalloidin staining. A similar effect could be observed in the stably transfected PHD2 knockdown cell clones 1B6 and 3B7. F-actin is at least in part responsible for shaping cell morphology as well as regulating cell migration. Cell migration was impaired significantly as a consequence of PHD2 knockdown in a scratch assay. Mechanistically, PHD2 knockdown resulted in activation of the RhoA (Ras homolog gene family member A)/Rho-associated kinase pathway with subsequent phosphorylation of cofilin. Because cofilin phosphorylation impairs its actin-severing function, this may explain the F-actin phenotype, thereby providing a functional link between PHD2-dependent signaling and cell motility.
Collapse
Affiliation(s)
- Sabine Vogel
- Department of Cardiovascular Physiology, Universitätsmedizin Göttingen, Georg-August University Göttingen, D-37073 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Meng J, Xia W, Tang J, Tang BL, Liang F. Dephosphorylation-dependent inhibitory activity of juxtanodin on filamentous actin disassembly. J Biol Chem 2010; 285:28838-49. [PMID: 20610382 DOI: 10.1074/jbc.m110.117887] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the vertebrate central nervous system, maturation of oligodendrocytes is accompanied by a dramatic transformation of cell morphology. Juxtanodin (JN) is an actin cytoskeleton-related oligodendroglial protein that promotes arborization of cultured oligodendrocytes. We performed in vitro and in culture experiments to further elucidate the biochemical effects, molecular interactions, and activity regulation of JN. Pulldown and co-sedimentation assays confirmed JN binding to filamentous but not globular beta-actin largely through a C-terminal domain of 14 amino acid residues. JN had much lower affinity to F-alpha-actin than to F-beta-actin. Bundling and actin polymerization assays revealed no JN influence on F-beta-actin cross-linking or G-beta-actin polymerization. Sedimentation assay, however, demonstrated that JN slowed the rate of F-beta-actin disassembly induced by dilution with F-actin depolymerization buffer. JN-S278E mutant, a mimic of phosphorylated JN at serine 278, exhibited a much diminished affinity/stabilizing effect on F-beta-actin. Immunoblotting revealed both phosphorylated and dephosphorylated native JN of the brain, with the former migrating slightly slower than the latter and becoming undetectable when brain lysate was subjected to in vitro dephosphorylation prior to being loaded for electrophoresis. In cultured OLN-93 cells, overexpression of JN promoted the formation of actin fibers and inhibited F-actin disassembly induced by latrunculin A. S278E phosphomimetic mutation resulted in loss of JN activity in cultured cells, whereas S278A, T258A, and T258E dephospho-/phosphomimetic mutations did not. These findings establish JN as an actin cytoskeleton-stabilizing protein that may play active roles in oligodendroglial differentiation and myelin formation. Specific phosphorylation of JN might serve as an important mechanism regulating JN functions.
Collapse
Affiliation(s)
- Jun Meng
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | |
Collapse
|
11
|
JIANG QF, CAI SX, YAN XQ. The Effect of Caldesmon Phosphorylation on Metastatic Tumor Cell Mobility*. PROG BIOCHEM BIOPHYS 2010. [DOI: 10.3724/sp.j.1206.2009.00545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
Wang CLA, Coluccio LM. New insights into the regulation of the actin cytoskeleton by tropomyosin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:91-128. [PMID: 20460184 DOI: 10.1016/s1937-6448(10)81003-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The actin cytoskeleton is regulated by a variety of actin-binding proteins including those constituting the tropomyosin family. Tropomyosins are coiled-coil dimers that bind along the length of actin filaments. In muscles, tropomyosin regulates the interaction of actin-containing thin filaments with myosin-containing thick filaments to allow contraction. In nonmuscle cells where multiple tropomyosin isoforms are expressed, tropomyosins participate in a number of cellular events involving the cytoskeleton. This chapter reviews the current state of the literature regarding tropomyosin structure and function and discusses the evidence that tropomyosins play a role in regulating actin assembly.
Collapse
|
13
|
Huang R, Grabarek Z, Wang CLA. Differential effects of caldesmon on the intermediate conformational states of polymerizing actin. J Biol Chem 2009; 285:71-9. [PMID: 19889635 DOI: 10.1074/jbc.m109.065078] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The actin-binding protein caldesmon (CaD) reversibly inhibits smooth muscle contraction. In non-muscle cells, a shorter CaD isoform co-exists with microfilaments in the stress fibers at the quiescent state, but the phosphorylated CaD is found at the leading edge of migrating cells where dynamic actin filament remodeling occurs. We have studied the effect of a C-terminal fragment of CaD (H32K) on the kinetics of the in vitro actin polymerization by monitoring the fluorescence of pyrene-labeled actin. Addition of H32K or its phosphorylated form either attenuated or accelerated the pyrene emission enhancement, depending on whether it was added at the early or the late phase of actin polymerization. However, the CaD fragment had no effect on the yield of sedimentable actin, nor did it affect the actin ATPase activity. Our findings can be explained by a model in which nascent actin filaments undergo a maturation process that involves at least two intermediate conformational states. If present at early stages of actin polymerization, CaD stabilizes one of the intermediate states and blocks the subsequent filament maturation. Addition of CaD at a later phase accelerates F-actin formation. The fact that CaD is capable of inhibiting actin filament maturation provides a novel function for CaD and suggests an active role in the dynamic reorganization of the actin cytoskeleton.
Collapse
Affiliation(s)
- Renjian Huang
- Boston Biomedical Research Institute, Watertown, Massachusetts 02472, USA
| | | | | |
Collapse
|
14
|
Huizing M, Helip-Wooley A, Westbroek W, Gunay-Aygun M, Gahl WA. Disorders of lysosome-related organelle biogenesis: clinical and molecular genetics. Annu Rev Genomics Hum Genet 2008; 9:359-86. [PMID: 18544035 DOI: 10.1146/annurev.genom.9.081307.164303] [Citation(s) in RCA: 274] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Lysosome-related organelles (LROs) are a heterogeneous group of vesicles that share various features with lysosomes, but are distinct in function, morphology, and composition. The biogenesis of LROs employs a common machinery, and genetic defects in this machinery can affect all LROs or only an individual LRO, resulting in a variety of clinical features. In this review, we discuss the main components of LRO biogenesis. We also summarize the function, composition, and resident cell types of the major LROs. Finally, we describe the clinical characteristics of the major human LRO disorders.
Collapse
Affiliation(s)
- Marjan Huizing
- Cell Biology of Metabolic Disorders Unit, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | | | | | |
Collapse
|
15
|
Han M, Dong LH, Zheng B, Shi JH, Wen JK, Cheng Y. Smooth muscle 22 alpha maintains the differentiated phenotype of vascular smooth muscle cells by inducing filamentous actin bundling. Life Sci 2008; 84:394-401. [PMID: 19073196 DOI: 10.1016/j.lfs.2008.11.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 11/11/2008] [Accepted: 11/13/2008] [Indexed: 10/21/2022]
Abstract
AIM Smooth muscle 22 alpha (SM22 alpha) is not required for the development and basal homeostatic function of smooth muscle cells (SMCs). However, a recent study demonstrated that SM22 alpha plays a role in inhibiting the phenotypic modulation of vascular SMCs (VSMCs) from contractile to synthetic/proliferative cells. The present study investigated the mechanism underlying the SM22 alpha-mediated maintenance of the contractile phenotype of VSMCs. MAIN METHODS The redifferentiation of synthetic SMCs was induced by serum deprivation for 48-72 h. The expression plasmids containing full-length cDNA of rat SM22 alpha and a vector expressing SM22 alpha antisense transcripts were constructed, respectively. Coimmunoprecipitation, cosedimentation assay and immunofluorescence analyses were used to detect the interaction of SM22 alpha with F-actin. KEY FINDINGS The results revealed that SM22 alpha directly interacted and colocalized with F-actin and thus participated in the organization of the actin cytoskeleton in differentiated VSMCs. SM22 alpha facilitated the assembly of actin filaments into bundles. The blockade of SM22 alpha expression by SM22 alpha antisense RNA led to the thinning and dispersion of actin filaments. Consequently, the ratio of F-actin to globular (G)-actin was reduced, and the cell contractility was lost. SIGNIFICANCE The SM22 alpha-induced F-actin bundling enhances the contractility and mobility of VSMCs, and the activity of SM22 alpha is necessary for maintaining the differentiated phenotype of VSMCs.
Collapse
Affiliation(s)
- Mei Han
- Department of Biochemistry and Molecular Biology, Institute of Basic Medicine, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | | | | | | | | | | |
Collapse
|
16
|
Chen HH, Murchland I, Booker GW. Assignment of the 1H, 13C and 15N resonances of the calponin homology-2 domain of alpha-actinin-4. BIOMOLECULAR NMR ASSIGNMENTS 2008; 2:195-7. [PMID: 19636903 DOI: 10.1007/s12104-008-9119-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 09/08/2008] [Indexed: 05/28/2023]
Abstract
We report the assignment of the 110 amino acid second calponin homology domain of human alpha-actinin-4. The two calponin homology domains of alpha-actinin combine to regulate F-actin binding.
Collapse
Affiliation(s)
- Huang-Hui Chen
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, 5005, Australia
| | | | | |
Collapse
|
17
|
Washington RW, Knecht DA. Actin binding domains direct actin-binding proteins to different cytoskeletal locations. BMC Cell Biol 2008; 9:10. [PMID: 18269770 PMCID: PMC2275727 DOI: 10.1186/1471-2121-9-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Accepted: 02/13/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Filamin (FLN) and non-muscle alpha-actinin are members of a family of F-actin cross-linking proteins that utilize Calponin Homology domains (CH-domain) for actin binding. Although these two proteins have been extensively characterized, little is known about what regulates their binding to F-actin filaments in the cell. RESULTS We have constructed fusion proteins consisting of green fluorescent protein (GFP) with either the entire cross-linking protein or its actin-binding domain (ABD) and examined the localization of these fluorescent proteins in living cells under a variety of conditions. The full-length fusion proteins, but not the ABD's complemented the defects of cells lacking both endogenous proteins indicating that they are functional. The localization patterns of filamin (GFP-FLN) and alpha-actinin (GFP-alphaA) were overlapping but distinct. GFP-FLN localized to the peripheral cell cortex as well as to new pseudopods of unpolarized cells, but was observed to localize to the rear of polarized cells during cAMP and folate chemotaxis. GFP-alphaA was enriched in new pseudopods and at the front of polarized cells, but in all cases was absent from the peripheral cortex. Although both proteins appear to be involved in macropinocytosis, the association time of the GFP-probes with the internalized macropinosome differed. Surprisingly, the localization of the GFP-actin-binding domain fusion proteins precisely reflected that of their respective full length constructs, indicating that the localization of the protein was determined by the actin-binding domain alone. When expressed in a cell line lacking both filamin and alpha-actinin, the probes maintain their distinct localization patterns suggesting that they are not functionally redundant. CONCLUSION These observations strongly suggest that the regulation of the binding of these proteins to actin filaments is built into the actin-binding domains. We suggest that different actin binding domains have different affinities for F-actin filaments in functionally distinct regions of the cytoskeleton.
Collapse
Affiliation(s)
- Raymond W Washington
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
| | | |
Collapse
|
18
|
Wang CLA. Caldesmon and the regulation of cytoskeletal functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 644:250-72. [PMID: 19209827 DOI: 10.1007/978-0-387-85766-4_19] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Caldesmon (CaD) is an extraordinary actin-binding protein, because in addition to actin, it also bindsmyosin, calmodulin and tropomyosin. As a component of the smoothmuscle and nonmuscle contractile apparatus CaD inhibits the actomyosin ATPase activity and its inhibitory action is modulated by both Ca2+ and phosphorylation. The multiplicity of binding partners and diverse biochemical properties suggest CaD is a potent and versatile regulatory protein both in contractility and cell motility. However, after decades ofinvestigation in numerous laboratories, hard evidence is still lacking to unequivocally identify its in vivo functions, although indirect evidence is mounting to support an important role in connection with the actin cytoskeleton. This chapter reviews the highlights of the past findings and summarizes the current views on this protein, with emphasis of its interaction with tropomyosin.
Collapse
Affiliation(s)
- C L Albert Wang
- Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA.
| |
Collapse
|
19
|
Stewman SF, Dinner AR. Lattice model for self-assembly with application to the formation of cytoskeletal-like structures. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:016103. [PMID: 17677529 DOI: 10.1103/physreve.76.016103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 03/08/2007] [Indexed: 05/16/2023]
Abstract
We introduce a stochastic approach for self-assembly in systems far from equilibrium. The building blocks are represented by a lattice of discrete variables (Potts-like spins), and physically meaningful mechanisms are obtained by restricting transitions through spatially local rules based on experimental data. We use the method to study nucleation of filopodia-like bundles in a system consisting of purified actin, fascin, actin-related protein 2/3 , and beads coated with Wiskott-Aldrich syndrome protein. Consistent with previous speculation based on static experimental images, we find that bundles derive from Lambda-precursor-like patterns of spins on the lattice. The ratcheting of the actin network relative to the surface that represents beads plays an important role in determining the number and orientation of bundles due to the fact that branching is the primary means for generating barbed ends pointed in directions that allow rapid filament growth. By enabling the de novo formation of coexisting morphologies without the computational cost of explicit representation of proteins, the approach introduced complements earlier models of cytoskeletal behavior in vitro and in vivo.
Collapse
Affiliation(s)
- Shannon F Stewman
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | | |
Collapse
|
20
|
Takamoto K, Kamal JKA, Chance MR. Biochemical implications of a three-dimensional model of monomeric actin bound to magnesium-chelated ATP. Structure 2007; 15:39-51. [PMID: 17223531 DOI: 10.1016/j.str.2006.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 11/06/2006] [Accepted: 11/18/2006] [Indexed: 11/19/2022]
Abstract
Actin structure is of intense interest in biology due to its importance in cell function and motility mediated by the spatial and temporal regulation of actin monomer-filament interconversions in a wide range of developmental and disease states. Despite this interest, the structure of many functionally important actin forms has eluded high-resolution analysis. Due to the propensity of actin monomers to assemble into filaments structural analysis of Mg-bound actin monomers has proven difficult, whereas high-resolution structures of actin with a diverse array of ligands that preclude polymerization have been quite successful. In this work, we provide a high-resolution structural model of the Mg-ATP-actin monomer using a combination of computational methods and experimental footprinting data that we have previously published. The key conclusion of this study is that the structure of the nucleotide binding cleft defined by subdomains 2 and 4 is essentially closed, with specific contacts between two subdomains predicted by the data.
Collapse
Affiliation(s)
- Keiji Takamoto
- Case Center for Proteomics, Case Western Reserve University, 10090 Euclid Avenue, Cleveland, OH 44106, USA.
| | | | | |
Collapse
|
21
|
Alafag JII, Moon EK, Hong YC, Chung DI, Kong HH. Molecular and biochemical characterization of a novel actin bundling protein in Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2007; 44:331-41. [PMID: 17170575 PMCID: PMC2559136 DOI: 10.3347/kjp.2006.44.4.331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Actin binding proteins play key roles in cell structure and movement particularly as regulators of the assembly, stability and localization of actin filaments in the cytoplasm. In the present study, a cDNA clone encoding an actin bundling protein named as AhABP was isolated from Acanthamoeba healyi, a causative agent of granulomatous amebic encephalitis. This clone exhibited high similarity with genes of Physarum polycephalum and Dictyostelium discoideum, which encode actin bundling proteins. Domain search analysis revealed the presence of essential conserved regions, i.e., an active actin binding site and 2 putative calcium binding EF-hands. Transfected amoeba cells demonstrated that AhABP is primarily localized in phagocytic cups, peripheral edges, pseudopods, and in cortical cytoplasm where actins are most abundant. Moreover, AhABP after the deletion of essential regions formed ellipsoidal inclusions within transfected cells. High-speed co-sedimentation assays revealed that AhABP directly interacted with actin in the presence of up to 10 microM of calcium. Under the electron microscope, thick parallel bundles were formed by full length AhABP, in contrast to the thin actin bundles formed by constructs with deletion sites. In the light of these results, we conclude that AhABP is a novel actin bundling protein that is importantly associated with actin filaments in the cytoplasm.
Collapse
Affiliation(s)
- Joanna It-Itan Alafag
- Department of Parasitology, Kyungpook National University School of Medicine, Daegu, Korea
| | | | | | | | | |
Collapse
|
22
|
Fiaschi T, Cozzi G, Raugei G, Formigli L, Ramponi G, Chiarugi P. Redox regulation of beta-actin during integrin-mediated cell adhesion. J Biol Chem 2006; 281:22983-91. [PMID: 16757472 DOI: 10.1074/jbc.m603040200] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Redox sensitivity of actin toward an exogenous oxidative stress has recently been reported. We report here the first evidence of in vivo actin redox regulation by a physiological source of reactive oxygen species, specifically those species generated by integrin receptors during cell adhesion. Actin oxidation takes place via the formation of a mixed disulfide between cysteine 374 and glutathione; this modification is essential for spreading and for cytoskeleton organization. Impairment of actin glutathionylation, either through GSH depletion or expression of the C374A redox-insensitive mutant, greatly affects cell spreading and the formation of stress fibers, leading to inhibition of the disassembly of the actinomyosin complex. These data suggest that actin glutathionylation is essential for cell spreading and cytoskeleton organization and that it plays a key role in disassembly of actinomyosin complex during cell adhesion.
Collapse
Affiliation(s)
- Tania Fiaschi
- Department of Biochemical Sciences, Center of Excellence for Scientific Research DENOTHE, Department of Anatomy, University of Florence, Italy
| | | | | | | | | | | |
Collapse
|
23
|
Galkin VE, Orlova A, Fattoum A, Walsh MP, Egelman EH. The CH-domain of calponin does not determine the modes of calponin binding to F-actin. J Mol Biol 2006; 359:478-85. [PMID: 16626733 DOI: 10.1016/j.jmb.2006.03.044] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2006] [Revised: 03/15/2006] [Accepted: 03/20/2006] [Indexed: 11/30/2022]
Abstract
Many actin-binding proteins have been observed to have a modular architecture. One of the most abundant modules is the calponin-homology (CH) domain, found as tandem repeats in proteins that cross-link actin filaments (such as fimbrin, spectrin and alpha-actinin) or link the actin cytoskeleton to intermediate filaments (such as plectin). In proteins such as the eponymous calponin, IQGAP1, and Scp1, a single CH-domain exists, but there has been some controversy over whether this domain binds to actin filaments. A previous three-dimensional reconstruction of the calponin-F-actin complex has led to the conclusion that the visualized portion of calponin bound to actin belongs to its amino-terminal homology (CH) domain. We show, using a calponin fragment lacking the CH-domain, that this domain is not bound to F-actin, and cannot be positioning calponin on F-actin as hypothesized. Further, using classification methods, we show a multiplicity in cooperative modes of binding of calponin to F-actin, similar to what has been observed for other actin-binding proteins such as tropomyosin and cofilin. Our results suggest that the form and function of the structurally conserved CH-domain found in many other actin-binding proteins have diverged. This has broad implications for inferring function from the presence of structurally conserved domains.
Collapse
Affiliation(s)
- Vitold E Galkin
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908-0733, USA
| | | | | | | | | |
Collapse
|
24
|
Abstract
Synapses are highly specialized intercellular junctions that mediate the transmission of information between axons and target cells. A fundamental property of synapses is their ability to modify the efficacy of synaptic communication through various forms of synaptic plasticity. Recent developments in imaging techniques have revealed that synapses exhibit a high degree of morphological plasticity under basal conditions and also in response to neuronal activity that induces alterations in synaptic strength. The underlying molecular basis for this morphological plasticity has attracted much attention, yet its functional significance to the mechanisms of synaptic transmission and synaptic plasticity remains elusive. These morphological changes ultimately require the dynamic actin cytoskeleton, which is the major structural component of synapses. Delineating the physiological roles of the actin cytoskeleton in supporting synaptic transmission and synaptic plasticity, therefore, paves the way for gaining molecular insights into when and how synaptic machineries couple synapse form and function.
Collapse
Affiliation(s)
- Christian Dillon
- MRC Cell Biology Unit and Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
| | | |
Collapse
|
25
|
Kierfeld J, Kühne T, Lipowsky R. Discontinuous unbinding transitions of filament bundles. PHYSICAL REVIEW LETTERS 2005; 95:038102. [PMID: 16090774 DOI: 10.1103/physrevlett.95.038102] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2004] [Indexed: 05/03/2023]
Abstract
Bundles of semiflexible polymers such as actin filaments are studied theoretically. The bundle formation is governed by attractive filament interactions mediated by cross-linking sticker molecules. Using a combination of analytical arguments and Monte Carlo simulations, it is shown that the formation of bundles of parallel filaments requires a threshold concentration of linkers which becomes independent of the filament number for large bundles. The unbinding of bundles happens in a single, discontinuous transition. We discuss the behavior of the bundle thickness at and below the transition. In the bound phase, large bundles tend to segregate into sub-bundles due to slow kinetics. Our results are in qualitative agreement with experiments on F-actin in the presence of the cross-linking protein alpha-actinin.
Collapse
Affiliation(s)
- Jan Kierfeld
- Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14424 Potsdam, Germany
| | | | | |
Collapse
|
26
|
Li Z, McNulty DE, Marler KJM, Lim L, Hall C, Annan RS, Sacks DB. IQGAP1 promotes neurite outgrowth in a phosphorylation-dependent manner. J Biol Chem 2005; 280:13871-8. [PMID: 15695813 DOI: 10.1074/jbc.m413482200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In eukaryotic cells IQGAP1 binds to and alters the function of several proteins, including actin, E-cadherin, beta-catenin, Cdc42, and Rac1. Yeast IQGAP1 homologues have an important role in cytoskeletal organization, suggesting that modulation of the cytoskeleton is a fundamental role of IQGAP1. Phosphorylation is a common mechanism by which cells regulate protein function. Here we demonstrate that endogenous IQGAP1 is highly phosphorylated in MCF-7 human breast epithelial cells. Moreover, incubation of cells with phorbol 12-myristate 13-acetate (PMA) stimulated phosphate incorporation into IQGAP1. By using mass spectrometry, Ser-1443 was identified as the major site phosphorylated on IQGAP1 in intact cells treated with PMA. Ser-1441 was also phosphorylated but to a lesser extent. In vitro analysis with purified proteins documented that IQGAP1 is a substrate for protein kinase Cepsilon, which catalyzes phosphorylation on Ser-1443. Consistent with these findings, inhibition of cellular protein kinase C via bisindolymaleimide abrogated Ser-1443 phosphorylation in response to PMA. To elucidate the biological sequelae of phosphorylation, Ser-1441 and Ser-1443 were converted either to alanine, to create a nonphosphorylatable construct, or to glutamic acid and aspartic acid, respectively, to generate a phosphomimetic IQGAP1. Although overexpression of wild type IQGAP1 promoted neurite outgrowth in N1E-115 neuroblastoma cells, the nonphosphorylatable IQGAP1 S1441A/S1443A had no effect. In contrast, the S1441E/S1443D mutation markedly enhanced the ability of IQGAP1 to induce neurite outgrowth. Our data disclose that IQGAP1 is phosphorylated at multiple sites in intact cells and that phosphorylation of IQGAP1 will alter its ability to regulate the cytoskeleton of neuronal cells.
Collapse
Affiliation(s)
- Zhigang Li
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Otey CA, Rachlin A, Moza M, Arneman D, Carpen O. The palladin/myotilin/myopalladin family of actin-associated scaffolds. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 246:31-58. [PMID: 16164966 DOI: 10.1016/s0074-7696(05)46002-7] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The dynamic remodeling of the actin cytoskeleton plays a critical role in cellular morphogenesis and cell motility. Actin-associated scaffolds are key to this process, as they recruit cohorts of actin-binding proteins and associated signaling complexes to subcellular sites where remodeling is required. This review is focused on a recently discovered family of three proteins, myotilin, palladin, and myopalladin, all of which function as scaffolds that regulate actin organization. While myotilin and myopalladin are most abundant in skeletal and cardiac muscle, palladin is ubiquitously expressed in the organs of developing vertebrates. Palladin's function has been investigated primarily in the central nervous system and in tissue culture, where it appears to play a key role in cellular morphogenesis. The three family members each interact with specific molecular partners: all three bind to alpha-actinin; in addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). Since mutations in myotilin result in two forms of muscle disease, an essential role for this family member in organizing the skeletal muscle sarcomere is implied.
Collapse
Affiliation(s)
- Carol A Otey
- Department of Cell and Molecular Physiology and the Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | | | | | | | | |
Collapse
|
28
|
Abstract
Mechanical work in cells is performed by specialized motor proteins that operate in a continuous mechanochemical cycle. Less complex, but still efficient, 'one-shot' motors evolved based on the assembly and disassembly of polymers. We review the mechanisms of pushing and pulling by actin and microtubule filaments and the organizational principles of actin networks. We show how these polymer force generators are used for the propulsion of intracellular pathogens, protrusion of lamellipodia and mitotic movements. We discuss several examples of cellular forces generated by the assembly and disassembly of polymer gels.
Collapse
Affiliation(s)
- Alex Mogilner
- Department of Mathematics, University of California, Davis, CA 95616, USA.
| | | |
Collapse
|
29
|
Redondo PC, Salido GM, Pariente JA, Rosado JA. Dual effect of hydrogen peroxide on store-mediated calcium entry in human platelets. Biochem Pharmacol 2004; 67:1065-76. [PMID: 15006543 DOI: 10.1016/j.bcp.2003.10.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Accepted: 10/29/2003] [Indexed: 11/17/2022]
Abstract
Redox regulation is important for the modulation of cytosolic Ca(2+) concentration. Hence, we have investigated the effect of H(2)O(2) on store-mediated Ca(2+) entry (SMCE). In fura-2-loaded human platelets treatment with H(2)O(2) resulted in a concentration-dependent increase in Ca(2+) release from intracellular stores, while the effect on Ca(2+) entry was biphasic. In addition, 1mM H(2)O(2) reduced SMCE induced by agonists. The inhibitory effect of 1mM H(2)O(2) was prevented by inhibition of actin polymerization with cytochalasin D. Consistent with this, we found that 10microM H(2)O(2) and store depletion by treatment with thapsigargin plus ionomycin induced a similar temporal sequence of actin reorganization, while exposure to 1mM H(2)O(2) shifted the dynamics between polymerization and depolymerization in favor of the former. One millimolar H(2)O(2)-induced polymerization was reduced by treatment with methyl 2,5-dihydroxycinnamate and farnesylthioacetic acid, inhibitors of tyrosine kinases and Ras superfamily proteins, respectively. Finally, exposure to 1mM H(2)O(2) significantly increased store depletion-induced p60(src) activation. We conclude that H(2)O(2) exerted a biphasic effect on SMCE. The inhibitory role of high H(2)O(2) concentrations is mediated by an abnormal actin reorganization pattern involving both Ras- and tyrosine kinases-dependent pathways.
Collapse
Affiliation(s)
- Pedro C Redondo
- Department of Physiology, Faculty of Veterinary Sciences, University of Extremadura, 10071 Cáceres, Spain.
| | | | | | | |
Collapse
|
30
|
Sahasrabuddhe AA, Bajpai VK, Gupta CM. A novel form of actin in Leishmania: molecular characterisation, subcellular localisation and association with subpellicular microtubules. Mol Biochem Parasitol 2004; 134:105-14. [PMID: 14747148 DOI: 10.1016/j.molbiopara.2003.11.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To study the occurrence and subcellular distribution of actin in trypanosomatid parasites, we have cloned and overexpressed Leishmania donovani actin gene in bacteria, purified the protein, and employed the affinity purified rabbit polyclonal anti-recombinant actin antibodies as a probe to study the organisation and subcellular distribution of actin in Leishmania cells. The Leishmania actin did not cross react with antimammalian actin antibodies but was readily recognized by the anti-Leishmania actin antibodies in both the promastigote and amastigote forms of the parasite. About 10(6) copies per cell of this protein (M(r) 42.05 kDa) were present in the Leishmania promastigote. Unlike other eukaryotic actins, the oligomeric forms of Leishmania actin were not stained by phalloidin nor were dissociated by actin filament-disrupting agents, like Latrunculin B and Cytochalasin D. Analysis of the primary structure of this protein revealed that these unusual characteristics may be related to the presence of highly diverged amino acids in the DNase I-binding loop (amino acids 40-50) and the hydrophobic plug (amino acids 262-272) regions of Leishmania actin. The subcellular distribution of actin was studied in the Leishmania promastigotes by employing immunoelectron and immunofluorescence microscopies. This protein was present not only in the flagella, flagellar pocket, nucleus and the kinetoplast but it was also localized on the nuclear, vacuolar and cytoplasmic face of the plasma membranes. Further, the plasma membrane-associated actin was colocalised with subpellicular microtubules, while most of the actin present in the kinetoplast colocalised with the k-DNA network. These results clearly indicate that Leishmania contains a novel form of actin which may structurally and functionally differ from other eukaryotic actins. The functional significance of these observations is discussed.
Collapse
Affiliation(s)
- Amogh A Sahasrabuddhe
- Division of Molecular and Structural Biology, Central Drug Research Institute, Lucknow 226 001, India
| | | | | |
Collapse
|
31
|
Abstract
Actin performs structural as well as motor-like functions in eukaryotic cells. Orthologues of actin have also been identified in bacteria, where they perform an essential function during cell growth. Bacterial actins are implicated in the maintenance of rod-shaped cell morphology, and appear to form a cytoskeletal structure, localising as helical filaments underneath the cell membrane. Recently, a plasmid-borne actin orthologue has been shown to perform a mitotic-like function during segregation of a plasmid, and chromosomally encoded actin proteins were found to play an important role in chromosome segregation. Based on the findings that actin filaments are dynamic structures in two bacterial species, we propose that actins perform motor functions rather than a purely structural role in bacteria. We suggest that an intracellular motor exists in bacteria that could be derived from an ancestral actin motor that was present in cells early in evolution.
Collapse
Affiliation(s)
- Peter L Graumann
- Biochemie, Fachbereich Chemie, Philipps-Universität Marburg, Germany.
| | | |
Collapse
|
32
|
Winder SJ, Jess T, Ayscough KR. SCP1 encodes an actin-bundling protein in yeast. Biochem J 2003; 375:287-95. [PMID: 12868959 PMCID: PMC1223692 DOI: 10.1042/bj20030796] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Revised: 07/04/2003] [Accepted: 07/18/2003] [Indexed: 11/17/2022]
Abstract
The association of F-actin (filamentous actin) with a large number of binding proteins is essential for cellular function. Actin-binding proteins control the dynamics of actin filaments, nucleate new filaments and facilitate formation of higher-order structures such as actin bundles. The yeast gene SCP1 encodes a small protein with significant homology to mammalian SM22/transgelin. We have investigated the role of Scp1p in budding yeast to probe the fundamental role of this family of proteins. Here, we demonstrate that Scp1p binds to F-actin and induces the formation of tight F-actin bundles in vitro. Deletion of SCP1 in yeast lacking the actin-bundling protein, fimbrin (Sac6p), exacerbates the disrupted actin phenotype and enhances latrunculin-A sensitivity. Furthermore, Scp1p co-localizes with actin in cortical patches and its localization is lost in the presence of latrunculin-A. Our data support a role for Scp1p in bundling actin filaments and, in concert with Sac6p, acting as a second actin-bundling activity crucial to the stability of the yeast actin cytoskeleton.
Collapse
Affiliation(s)
- Steven J Winder
- Institute of Biomedical and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, UK.
| | | | | |
Collapse
|
33
|
Graceffa P, Dominguez R. Crystal structure of monomeric actin in the ATP state. Structural basis of nucleotide-dependent actin dynamics. J Biol Chem 2003; 278:34172-80. [PMID: 12813032 DOI: 10.1074/jbc.m303689200] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A nucleotide-dependent conformational change regulates actin filament dynamics. Yet, the structural basis of this mechanism remains controversial. The x-ray crystal structure of tetramethylrhodamine-5-maleimide-actin with bound AMPPNP, a non-hydrolyzable ATP analog, was determined to 1.85-A resolution. A comparison of this structure to that of tetramethylrhodamine-5-maleimide-actin with bound ADP, determined previously under similar conditions, reveals how the release of the nucleotide gamma-phosphate sets in motion a sequence of events leading to a conformational change in subdomain 2. The side chain of Ser-14 in the catalytic site rotates upon Pi release, triggering the rearrangement of the loop containing the methylated His-73, referred to as the sensor loop. This in turn causes a transition in the DNase I-binding loop in subdomain 2 from a disordered loop in ATP-actin to an ordered alpha-helix in ADP-actin. Despite this conformational change, the nucleotide cleft remains closed in ADP-actin, similar to ATP-actin. An analysis of the existing structures of members of the actin superfamily suggests that the cleft is open in the nucleotide-free state.
Collapse
Affiliation(s)
- Philip Graceffa
- Boston Biomedical Research Institute, Watertown, Massachusetts 02472, USA
| | | |
Collapse
|
34
|
Goodman A, Goode BL, Matsudaira P, Fink GR. The Saccharomyces cerevisiae calponin/transgelin homolog Scp1 functions with fimbrin to regulate stability and organization of the actin cytoskeleton. Mol Biol Cell 2003; 14:2617-29. [PMID: 12857851 PMCID: PMC165663 DOI: 10.1091/mbc.e03-01-0028] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Revised: 03/07/2003] [Accepted: 03/07/2003] [Indexed: 01/04/2023] Open
Abstract
Calponins and transgelins are members of a conserved family of actin-associated proteins widely expressed from yeast to humans. Although a role for calponin in muscle cells has been described, the biochemical activities and in vivo functions of nonmuscle calponins and transgelins are largely unknown. Herein, we have used genetic and biochemical analyses to characterize the budding yeast member of this family, Scp1, which most closely resembles transgelin and contains one calponin homology (CH) domain. We show that Scp1 is a novel component of yeast cortical actin patches and shares in vivo functions and biochemical activities with Sac6/fimbrin, the one other actin patch component that contains CH domains. Purified Scp1 binds directly to filamentous actin, cross-links actin filaments, and stabilizes filaments against disassembly. Sequences in Scp1 sufficient for actin binding and cross-linking reside in its carboxy terminus, outside the CH domain. Overexpression of SCP1 suppresses sac6Delta defects, and deletion of SCP1 enhances sac6Delta defects. Together, these data show that Scp1 and Sac6/fimbrin cooperate to stabilize and organize the yeast actin cytoskeleton.
Collapse
Affiliation(s)
- Anya Goodman
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | | | | | | |
Collapse
|
35
|
Alaoui-Jamali MA, Qiang H. The interface between ErbB and non-ErbB receptors in tumor invasion: clinical implications and opportunities for target discovery. Drug Resist Updat 2003; 6:95-107. [PMID: 12729807 DOI: 10.1016/s1368-7646(03)00024-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The molecular switches by which malignant cancer cells evolve from a confined to an invasive state are poorly understood, but seem to involve a progressive activation of a signaling network shared by several growth factor receptors and non-receptor molecules. Abnormal expression of ErbB tyrosine kinase receptors, commonly seen in cancer, is an early event in the invasive process, which makes these receptors exciting targets for drug discovery. The past few years have been full of promise for ErbB targeting in the context of receptor overexpression, but also fraught with disappointment as clinical efficacy has often been hampered by potential problems such as the heterogeneity of receptor expression within the same tumor, and the extensive cooperative signaling among ErbB and non-ErbB receptors. Cooperative signaling is a common characteristic of invasive cancer cells, and is believed to dictate the genetic program that controls invasion switches. Molecular studies on the combinatorial signaling involved in tumor invasion are becoming a fertile area for target discovery in cancer. This review discusses how cooperative signaling between ErbB and non-ErbB receptors regulates tumor invasion and hence provides multiple opportunities for drug discovery, and how current therapies and investigational drugs could pave the way to even more potent alternative combinatorial therapeutic approaches for invasive cancers.
Collapse
Affiliation(s)
- Moulay A Alaoui-Jamali
- Department of Medicine, Lady Davis Institute for Medical Research, McGill University, Montreal, Que., Canada.
| | | |
Collapse
|