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Poobalasingam T, Bianco F, Oozeer F, Gordon-Weeks PR. The drebrin/EB3 pathway regulates cytoskeletal dynamics to drive neuritogenesis in embryonic cortical neurons. J Neurochem 2021; 160:185-202. [PMID: 34478582 DOI: 10.1111/jnc.15502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/12/2021] [Accepted: 08/22/2021] [Indexed: 02/01/2023]
Abstract
Co-ordinating the dynamic behaviour of actin filaments (F-actin) and microtubules in filopodia is an important underlying process in neuritogenesis, but the molecular pathways involved are ill-defined. The drebrin/end-binding protein 3 (EB3) pathway is a candidate pathway for linking F-actin to microtubules in filopodia. Drebrin binds F-actin and, simultaneously, the microtubule-binding protein EB3 when bound to microtubule plus-ends. We assessed the effect on neuritogenesis of gain- or loss-of-function of proteins in the drebrin/EB3 pathway in rat embryonic cortical neurons in culture. Loss-of-function of drebrin by gene editing or pharmacological inhibition of drebrin binding to F-actin reduced the number of dynamic microtubules in the cell periphery and simultaneously delayed the initiation of neuritogenesis, whereas over-expression of drebrin induced supernumerary neurites. Similarly, loss of EB3 inhibited neuritogenesis, whereas loss of end-binding protein 1 (EB1), a related protein that does not bind to drebrin, did not affect neuritogenesis. Over-expression of EB3, but not EB1, induced supernumerary neurites. We discovered that EB3 is more proximally located at dynamic microtubule plus-ends than EB1 in growth cone filopodia allowing for continuous microtubule elongation as the drebrin/EB3 pathway zippers microtubules to F-actin in filopodia. Finally, we showed that preventing the entry of dynamic microtubules into filopodia using a pharmacological inhibitor of microtubule dynamics is associated with a loss of EB3, but not EB1, from microtubule plus-ends and a concurrent attenuation of neuritogenesis. Collectively, these findings support the idea that neuritogenesis depends on microtubule/F-actin zippering in filopodia orchestrated by the drebrin/EB3 pathway.
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Affiliation(s)
- Thanushiyan Poobalasingam
- William Harvey Research Institute, Charter House Square, Queen Mary University of London, London, UK
| | - Francesca Bianco
- Department of Psychology & School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK
| | - Fazal Oozeer
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Phillip R Gordon-Weeks
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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2
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Bertling E, Blaesse P, Seja P, Kremneva E, Gateva G, Virtanen MA, Summanen M, Spoljaric I, Uvarov P, Blaesse M, Paavilainen VO, Vutskits L, Kaila K, Hotulainen P, Ruusuvuori E. Carbonic anhydrase seven bundles filamentous actin and regulates dendritic spine morphology and density. EMBO Rep 2021; 22:e50145. [PMID: 33719157 PMCID: PMC8025036 DOI: 10.15252/embr.202050145] [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: 02/03/2020] [Revised: 01/14/2021] [Accepted: 01/28/2021] [Indexed: 01/02/2023] Open
Abstract
Intracellular pH is a potent modulator of neuronal functions. By catalyzing (de)hydration of CO2 , intracellular carbonic anhydrase (CAi ) isoforms CA2 and CA7 contribute to neuronal pH buffering and dynamics. The presence of two highly active isoforms in neurons suggests that they may serve isozyme-specific functions unrelated to CO2 -(de)hydration. Here, we show that CA7, unlike CA2, binds to filamentous actin, and its overexpression induces formation of thick actin bundles and membrane protrusions in fibroblasts. In CA7-overexpressing neurons, CA7 is enriched in dendritic spines, which leads to aberrant spine morphology. We identified amino acids unique to CA7 that are required for direct actin interactions, promoting actin filament bundling and spine targeting. Disruption of CA7 expression in neocortical neurons leads to higher spine density due to increased proportion of small spines. Thus, our work demonstrates highly distinct subcellular expression patterns of CA7 and CA2, and a novel, structural role of CA7.
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Affiliation(s)
- Enni Bertling
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Peter Blaesse
- Institute of Physiology IWestfälische Wilhelms‐Universität MünsterMünsterGermany
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Patricia Seja
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Mari A Virtanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Milla Summanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Inkeri Spoljaric
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pavel Uvarov
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Laszlo Vutskits
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Kai Kaila
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pirta Hotulainen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Eva Ruusuvuori
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
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3
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Effects of neuronal drebrin on actin dynamics. Biochem Soc Trans 2021; 49:685-692. [PMID: 33739391 DOI: 10.1042/bst20200577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/14/2021] [Accepted: 02/23/2021] [Indexed: 11/17/2022]
Abstract
Drebrin is a key regulator of actin cytoskeleton in neuronal cells which is critical for synaptic plasticity, neuritogenesis, and neuronal migration. It is also known to orchestrate a cross-talk between actin and microtubules. Decreased level of drebrin is a hallmark of multiple neurodegenerative disorders such as Alzheimer's disease. Despite its established importance in health and disease, we still have a lot to learn about drebrin's interactome and its effects on cytoskeletal dynamics. This review aims to summarize the recently reported novel effects of drebrin on actin and its regulators. Here I will also reflect on the most recent progress made in understanding of the role of drebrin isoforms and posttranslational modifications on its functionality.
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Drebrin in Neuronal Migration and Axonal Growth. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:141-155. [PMID: 28865019 DOI: 10.1007/978-4-431-56550-5_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
During development, production of neurons from neural stem cells, migration of neurons from their birthplace to their final location, and extension of neurites, axons, and dendrites are important for the formation of functional neuronal circuits. The actin cytoskeleton has major roles in the morphological development of neurons. In this chapter, we focused on the distribution and function of the actin-binding protein, drebrin, to elucidate the importance of drebrin-bound F-actin in neurons during early developmental stages of neurons in embryonic, postnatal, and adult brains. There are three major isoforms of drebrin in the chicken brain (E1, E2, and A) and two major isoforms in the mammalian brain (E and A). Among these drebrin isoforms, drebrin E1 and E2 in chicken and drebrin E in the mammalian brain are involved in these neuronal stages. In migrating neurons of the developing and adult brain, drebrin is localized at the base of filopodia of leading processes, to regulate neuronal migration. In axonal growth cones, drebrin is localized in the transitional zone to regulate axonal growth by inhibiting actomyosin interactions and mediating the interactions between F-actin and microtubules. For axonal collateral branching, drebrin is localized at axonal actin patches and the base of filopodia, to accelerate the transition from actin patches to filopodia and stabilize the filopodia.
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Drebrin Regulation of Calcium Signaling in Immune Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [PMID: 28865026 DOI: 10.1007/978-4-431-56550-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Store-operated Ca2+ channels are plasma membrane channels that are activated by depletion of intracellular Ca2+ stores, resulting in an increase in intracellular Ca2+; however, little is known about their regulation. Our work has shown that the immunosuppressant compound BTP2, which blocks Ca2+ influx into cells, interacts with the actin-reorganizing protein, drebrin. Here we review the role of drebrin in the regulation of calcium signaling, with a focus on immune cells.
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Localization of Drebrin: Light Microscopy Study. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [PMID: 28865017 DOI: 10.1007/978-4-431-56550-5_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Developmental changes in the expression and localization of drebrin has been mainly analyzed in chick embryo and young rat by various anti-drebrin polyclonal and monoclonal antibodies. Immunoblot analysis demonstrated that the adult drebrin isoform (drebrin A) is restricted to neural tissues, while the embryonic drebrin isoforms (drebrin E1 and E2 in chicken and drebrin E in mammals) are found in a wide variety of tissues. In the developing brain, drebrin E (including chicken drebrin E2) is expressed in newly generated neurons. During neuronal migration, drebrin E is distributed ubiquitously within the neurons. Once drebrin A is expressed in the developing neuron, drebrin E is no longer present within the cell soma and accumulates in the growth cone of growing processes, resulting in the cessation of neuronal migration. The limited subcellular localization of drebrin A, which is possibly regulated by a drebrin A-specific mechanism, is likely to affect the localization of drebrin E. In the adult brain, drebrin is mainly localized in dendritic spines, but in some nuclei, drebrin can be detected in neuronal somata as well as dendritic spines. The fact that the developmental changes in drebrin expression highly correlate in time with the sensitive period of visual cortical plasticity in kittens suggests that synaptic plasticity depends on drebrin.
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Biochemistry of Drebrin and Its Binding to Actin Filaments. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:37-47. [DOI: 10.1007/978-4-431-56550-5_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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Majoul IV, Ernesti JS, Butkevich EV, Duden R. Drebrins and Connexins: A Biomedical Perspective. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:225-247. [DOI: 10.1007/978-4-431-56550-5_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Tai LM, Balu D, Avila-Munoz E, Abdullah L, Thomas R, Collins N, Valencia-Olvera AC, LaDu MJ. EFAD transgenic mice as a human APOE relevant preclinical model of Alzheimer's disease. J Lipid Res 2017; 58:1733-1755. [PMID: 28389477 PMCID: PMC5580905 DOI: 10.1194/jlr.r076315] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/06/2017] [Indexed: 01/12/2023] Open
Abstract
Identified in 1993, APOE4 is the greatest genetic risk factor for sporadic Alzheimer's disease (AD), increasing risk up to 15-fold compared with APOE3, with APOE2 decreasing AD risk. However, the functional effects of APOE4 on AD pathology remain unclear and, in some cases, controversial. In vivo progress to understand how the human (h)-APOE genotypes affect AD pathology has been limited by the lack of a tractable familial AD-transgenic (FAD-Tg) mouse model expressing h-APOE rather than mouse (m)-APOE. The disparity between m- and h-apoE is relevant for virtually every AD-relevant pathway, including amyloid-β (Aβ) deposition and clearance, neuroinflammation, tau pathology, neural plasticity and cerebrovascular deficits. EFAD mice were designed as a temporally useful preclinical FAD-Tg-mouse model expressing the h-APOE genotypes for identifying mechanisms underlying APOE-modulated symptoms of AD pathology. From their first description in 2012, EFAD mice have enabled critical basic and therapeutic research. Here we review insights gleaned from the EFAD mice and summarize future directions.
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Affiliation(s)
- Leon M Tai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Deebika Balu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Evangelina Avila-Munoz
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | | | - Riya Thomas
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Nicole Collins
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | | | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612.
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Shirao T, Hanamura K, Koganezawa N, Ishizuka Y, Yamazaki H, Sekino Y. The role of drebrin in neurons. J Neurochem 2017; 141:819-834. [PMID: 28199019 DOI: 10.1111/jnc.13988] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 12/27/2016] [Accepted: 01/11/2017] [Indexed: 01/13/2023]
Abstract
Drebrin is an actin-binding protein that changes the helical pitch of actin filaments (F-actin), and drebrin-decorated F-actin shows slow treadmilling and decreased rate of depolymerization. Moreover, the characteristic morphology of drebrin-decorated F-actin enables it to respond differently to the same signals from other actin cytoskeletons. Drebrin consists of two major isoforms, drebrin E and drebrin A. In the developing brain, drebrin E appears in migrating neurons and accumulates in the growth cones of axons and dendrites. Drebrin E-decorated F-actin links lamellipodium F-actin to microtubules in the growth cones. Then drebrin A appears at nascent synapses and drebrin A-decorated F-actin facilitates postsynaptic molecular assembly. In the adult brain, drebrin A-decorated F-actin is concentrated in the central region of dendritic spines. During long-term potentiation initiation, NMDA receptor-mediated Ca2+ influx induces the transient exodus of drebrin A-decorated F-actin via myosin II ATPase activation. Because of the unique physical characteristics of drebrin A-decorated F-actin, this exodus likely contributes to the facilitation of F-actin polymerization and spine enlargement. Additionally, drebrin reaccumulation in dendritic spines is observed after the exodus. In our drebrin exodus model of structure-based synaptic plasticity, reestablishment of drebrin A-decorated F-actin is necessary to keep the enlarged spine size during long-term potentiation maintenance. In this review, we introduce the genetic and biochemical properties of drebrin and the roles of drebrin in early stage of brain development, synaptic formation and synaptic plasticity. Further, we discuss the pathological relevance of drebrin loss in Alzheimer's disease. This article is part of the mini review series "60th Anniversary of the Japanese Society for Neurochemistry".
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Affiliation(s)
- Tomoaki Shirao
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Kenji Hanamura
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Noriko Koganezawa
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yuta Ishizuka
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Hiroyuki Yamazaki
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yuko Sekino
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.,Division of Pharmacology, National Institute of Health Sciences, Tokyo, Japan
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11
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12
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The Role of Drebrin in Cancer Cell Invasion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:375-389. [DOI: 10.1007/978-4-431-56550-5_23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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13
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Kojima N. Molecular Cloning of Drebrin: Progress and Perspectives. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:25-36. [DOI: 10.1007/978-4-431-56550-5_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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15
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The role of the drebrin/EB3/Cdk5 pathway in dendritic spine plasticity, implications for Alzheimer's disease. Brain Res Bull 2016; 126:293-299. [PMID: 27365229 DOI: 10.1016/j.brainresbull.2016.06.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 06/23/2016] [Accepted: 06/25/2016] [Indexed: 11/21/2022]
Abstract
The drebrin/EB3/Cdk5 intracellular signalling pathway couples actin filaments to dynamic microtubules in cellular settings where cells are changing shape. The pathway has been most intensively studied in neuronal development, particularly neuritogenesis and neuronal migration, and in synaptic plasticity at dendritic spines in mature neurons. Drebrin is an actin filament side-binding and bundling protein that stabilises actin filaments. The end-binding (EB) proteins are microtubule plus-end tracking proteins (+TIPs) that localise to the growing plus-ends of dynamic microtubules and regulate their behavior and the binding of other +TIP proteins. EB3 binds specifically to drebrin when drebrin is bound to actin filaments, for example at the base of a growth cone filopodium, and EB3 is located at the plus-end of a growing microtubule inserting into the filopodium. This interaction therefore forms the basis for coupling dynamic microtubules to actin filaments in growth cones of developing neurons. Appropriate responses to growth cone guidance cues depend on actin filament/microtubule co-ordination in the growth cone, although the role of the drebrin/EB3/Cdk5 pathway in this context has not been directly tested. A similar cytoskeleton coupling pathway operates in dendritic spines in mature neurons where the activity-dependent insertion of dynamic microtubules into dendritic spines is facilitated by drebrin binding to EB3. Microtubule insertion into dendritic spines drives spine maturation during long-term potentiation and therefore has a role in synaptic plasticity and memory formation. In Alzheimer's disease and related chronic neurodegenerative diseases, there is an early and dramatic loss of drebrin from dendritic spines that precedes synapse loss and neurodegeneration and might contribute to a failure of synaptic plasticity and hence to cognitive decline.
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Connexin43 Forms Supramolecular Complexes through Non-Overlapping Binding Sites for Drebrin, Tubulin, and ZO-1. PLoS One 2016; 11:e0157073. [PMID: 27280719 PMCID: PMC4900556 DOI: 10.1371/journal.pone.0157073] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 05/24/2016] [Indexed: 02/06/2023] Open
Abstract
Gap junctions are membrane specialization domains identified in most tissue types where cells abut each other. The connexin channels found in these membrane domains are conduits for direct cell-to-cell transfer of ions and molecules. Connexin43 (Cx43) is the most ubiquitous connexin, with critical roles in heart, skin, and brain. Several studies described the interaction between Cx43 and the cytoskeleton involving the actin binding proteins Zonula occludens (ZO-1) and drebrin, as well as with tubulin. However, a direct interaction has not been identified between drebrin and Cx43. In this study, co-IP and NMR experiments were used to demonstrate that the Cx43-CT directly interacts with the highly conserved N-terminus region of drebrin. Three Cx43-CT areas were found to be involved in drebrin binding, with residues 264–275 being critical for the interaction. Mimicking Src phosphorylation within this region (Y265) significantly disrupted the interaction between the Cx43-CT and drebrin. Immunofluorescence showed colocalization of Cx43, drebrin, and F-actin in astrocytes and Vero cells membrane, indicating that Cx43 forms a submembrane protein complex with cytoskeletal and scaffolding proteins. The co-IP data suggest that Cx43 indirectly interacts with F-actin through drebrin. Along with the known interaction of the Cx43-CT with ZO-1 and tubulin, the data presented here for drebrin indicate non-overlapping and separated binding sites for all three proteins for which simultaneous binding could be important in regulating cytoskeleton rearrangements, especially for neuronal migration during brain development.
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Law M, Lee Y, Morales JL, Ning G, Huang W, Pabon J, Kannan AK, Jeong AR, Wood A, Carter C, Mohinta S, Song J, August A. Cutting Edge: Drebrin-Regulated Actin Dynamics Regulate IgE-Dependent Mast Cell Activation and Allergic Responses. THE JOURNAL OF IMMUNOLOGY 2015; 195:426-30. [PMID: 26056254 DOI: 10.4049/jimmunol.1401442] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 05/15/2015] [Indexed: 11/19/2022]
Abstract
Mast cells play critical roles in allergic responses. Calcium signaling controls the function of these cells, and a role for actin in regulating calcium influx into cells has been suggested. We have previously identified the actin reorganizing protein Drebrin as a target of the immunosuppressant 3,5-bistrifluoromethyl pyrazole, which inhibits calcium influx into cells. In this study, we show that Drebrin(-/-) mice exhibit reduced IgE-mediated histamine release and passive systemic anaphylaxis, and Drebrin(-/-) mast cells also exhibit defects in FcεRI-mediated degranulation. Drebrin(-/-) mast cells exhibit defects in actin cytoskeleton organization and calcium responses downstream of the FcεRI, and agents that relieve actin reorganization rescue mast cell FcεRI-induced degranulation. Our results indicate that Drebrin regulates the actin cytoskeleton and calcium responses in mast cells, thus regulating mast cell function in vivo.
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Affiliation(s)
- Mankit Law
- Center for Molecular Immunology and Infectious Disease and Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16801; Immunology and Infectious Diseases Graduate Program, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16801; Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - YongChan Lee
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - J Luis Morales
- Center for Molecular Immunology and Infectious Disease and Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16801
| | - Gang Ning
- Microscopy and Cytometry Facility, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16801
| | - Weishan Huang
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Jonathan Pabon
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Arun K Kannan
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Ah-Reum Jeong
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Amie Wood
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Chavez Carter
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Sonia Mohinta
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Jihong Song
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
| | - Avery August
- Center for Molecular Immunology and Infectious Disease and Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16801; Immunology and Infectious Diseases Graduate Program, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16801; Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853; and
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Sonego M, Oberoi M, Stoddart J, Gajendra S, Hendricusdottir R, Oozeer F, Worth DC, Hobbs C, Eickholt BJ, Gordon-Weeks PR, Doherty P, Lalli G. Drebrin regulates neuroblast migration in the postnatal mammalian brain. PLoS One 2015; 10:e0126478. [PMID: 25945928 PMCID: PMC4422745 DOI: 10.1371/journal.pone.0126478] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 04/02/2015] [Indexed: 01/13/2023] Open
Abstract
After birth, stem cells in the subventricular zone (SVZ) generate neuroblasts that migrate along the rostral migratory stream (RMS) to become interneurons in the olfactory bulb (OB). This migration is crucial for the proper integration of newborn neurons in a pre-existing synaptic network and is believed to play a key role in infant human brain development. Many regulators of neuroblast migration have been identified; however, still very little is known about the intracellular molecular mechanisms controlling this process. Here, we have investigated the function of drebrin, an actin-binding protein highly expressed in the RMS of the postnatal mammalian brain. Neuroblast migration was monitored both in culture and in brain slices obtained from electroporated mice by time-lapse spinning disk confocal microscopy. Depletion of drebrin using distinct RNAi approaches in early postnatal mice affects neuroblast morphology and impairs neuroblast migration and orientation in vitro and in vivo. Overexpression of drebrin also impairs migration along the RMS and affects the distribution of neuroblasts at their final destination, the OB. Drebrin phosphorylation on Ser142 by Cyclin-dependent kinase 5 (Cdk5) has been recently shown to regulate F-actin-microtubule coupling in neuronal growth cones. We also investigated the functional significance of this phosphorylation in RMS neuroblasts using in vivo postnatal electroporation of phosphomimetic (S142D) or non-phosphorylatable (S142A) drebrin in the SVZ of mouse pups. Preventing or mimicking phosphorylation of S142 in vivo caused similar effects on neuroblast dynamics, leading to aberrant neuroblast branching. We conclude that drebrin is necessary for efficient migration of SVZ-derived neuroblasts and propose that regulated phosphorylation of drebrin on S142 maintains leading process stability for polarized migration along the RMS, thus ensuring proper neurogenesis.
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Affiliation(s)
- Martina Sonego
- Wolfson Centre for Age-Related Diseases, King’s College London, London, United Kingdom
| | - Michelle Oberoi
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, California, United States of America
| | - Jake Stoddart
- Wolfson Centre for Age-Related Diseases, King’s College London, London, United Kingdom
| | - Sangeetha Gajendra
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Rita Hendricusdottir
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Fazal Oozeer
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Daniel C. Worth
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Carl Hobbs
- Wolfson Centre for Age-Related Diseases, King’s College London, London, United Kingdom
| | - Britta J. Eickholt
- Cluster of Excellence NeuroCure and Institute of Biochemistry, Charité —Universitätsmedizin Berlin, Berlin, Germany
| | | | - Patrick Doherty
- Wolfson Centre for Age-Related Diseases, King’s College London, London, United Kingdom
| | - Giovanna Lalli
- Wolfson Centre for Age-Related Diseases, King’s College London, London, United Kingdom
- * E-mail:
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19
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Jung G, Kim EJ, Cicvaric A, Sase S, Gröger M, Höger H, Sialana FJ, Berger J, Monje FJ, Lubec G. Drebrin depletion alters neurotransmitter receptor levels in protein complexes, dendritic spine morphogenesis and memory-related synaptic plasticity in the mouse hippocampus. J Neurochem 2015; 134:327-39. [DOI: 10.1111/jnc.13119] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/16/2015] [Accepted: 03/27/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Gangsoo Jung
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Eun-Jung Kim
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Ana Cicvaric
- Department of Neurophysiology and Neuropharmacology; Center for Physiology and Pharmacology; Medical University of Vienna; Vienna Austria
| | - Sunetra Sase
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
| | - Marion Gröger
- Core Facility Imaging; Medical University of Vienna; Vienna Austria
| | - Harald Höger
- Core Unit of Biomedical Research; Division of Laboratory Animal Science and Genetics; Medical University of Vienna; Himberg Austria
| | | | - Johannes Berger
- Department of Pathobiology of the Nervous System; Center for Brain Research; Medical University of Vienna; Vienna Austria
| | - Francisco J. Monje
- Department of Neurophysiology and Neuropharmacology; Center for Physiology and Pharmacology; Medical University of Vienna; Vienna Austria
| | - Gert Lubec
- Department of Pediatrics; Medical University of Vienna; Vienna Austria
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20
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Li MW, Xiao X, Mruk DD, Lam YL, Lee WM, Lui WY, Bonanomi M, Silvestrini B, Cheng CY. Actin-binding protein drebrin E is involved in junction dynamics during spermatogenesis. SPERMATOGENESIS 2014; 1:123-136. [PMID: 22319661 DOI: 10.4161/spmg.1.2.16393] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The actin-based cytoskeleton plays a critical role in the seminiferous epithelium during spermatogenesis by conferring cell shape, adhesion, structural support and cell polarity to both Sertoli and developing germ cells, which are essential for spermatogonial stem cell renewal, maintenance of the stem cell niche, cell cycle progression, mitosis, meiosis, spermiogenesis and spermiation. However, few functional studies are found in the literature, which explore the functional significance of actin dynamics in these events. This by and large is due to a lack of information on the proteins that regulate actin dynamics. Herein, we report drebrin E is an integrated component of the apical ectoplasmic specialization (apical ES) and the basal ES at the blood-testis barrier (BTB) in the seminiferous epithelium of the adult rat testis. Using immunohistochemistry and dual-labeled immunofluorescence analysis, drebrin E was found to display a stage-specific localization at the apical ES, as well as at the basal ES at the BTB during the seminiferous epithelial cycle of spermatogenesis. Drebrin E was first detected in stage V tubules at the basal ES with the highest expression at the BTB at stages V and VI, but it diminished considerably by stages VII and VIII and was almost non-detectable until stage IV. At the apical ES, drebrin E was also first detected at stage V, surrounding the entire head of the elongating spermatid, but by stage VI its localization had "shifted" to localize most intensely and almost exclusively to the concave side of the spermatid head. In stage VII tubules, drebrin E co-localized with actin, as well as with two other actin regulatory proteins Eps8 (epidermal growth factor receptor pathway substrate 8, an actin capping and bundling protein) and Arp3 (actin-related protein 3, a component of the Arp2/3 complex known to regulate actin nucleation and branching). The localization of drebrin E at the apical ES was compromised following treatment of rats with adjudin, which is known to exert its destructive effects primarily at the apical ES by inducing premature loss of elongating/elongated spermatids from the epithelium, mimicking "spermiation." Instead of being restricted to the concave side of spermatid heads, drebrin E was found to be mis-localized in the seminiferous epithelium of adjudin-treated rats; it was also present on the convex side of elongating spermatids, but these cells were mis-oriented so that their heads no longer pointed toward the basement membrane. The expression of drebrin E by Sertoli cells was also found to be modulated by TGFβ3 and TNFα. Since Arp3, but not Eps8, was found to bind drebrin E; and cytokines were also shown to affect the cellular distribution of drebrin E and enhance the interaction between drebrin E and Arp3, these findings illustrate that cytokines may regulate BTB dynamics during the epithelial cycle by recruiting drebrin E and Arp3 to the BTB microenvironment to induce changes in the configuration of actin filament bundles at the basal ES. In summary, these findings illustrate drebrin E is working in concert with Arp3 to regulate actin filament bundles at both the apical and the basal ES in the testis, conferring adhesion and cell polarity at both sites during spermatogenesis.
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Affiliation(s)
- Michelle Wm Li
- Center for Biomedical Research; The Population Council; New York, NY USA
| | - Xiang Xiao
- Center for Biomedical Research; The Population Council; New York, NY USA
| | - Dolores D Mruk
- Center for Biomedical Research; The Population Council; New York, NY USA
| | - Yee-Ling Lam
- Center for Biomedical Research; The Population Council; New York, NY USA
| | - Will M Lee
- School of Biological Sciences; The University of Hong Kong; Hong Kong, China
| | - Wing-Yee Lui
- School of Biological Sciences; The University of Hong Kong; Hong Kong, China
| | | | | | - C Yan Cheng
- Center for Biomedical Research; The Population Council; New York, NY USA
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21
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Cheng CY, Mruk DD. Actin binding proteins and spermiogenesis: Some unexpected findings. SPERMATOGENESIS 2014; 1:99-104. [PMID: 22319657 DOI: 10.4161/spmg.1.2.16913] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/05/2011] [Accepted: 06/07/2011] [Indexed: 12/18/2022]
Abstract
Drebrin E, an actin-binding protein lacking intrinsic activity in the regulation of actin dynamics (e.g., polymerization, capping, nucleation, branching, cross-linking, bundling and severing), is known to recruit actin regulatory proteins to a specific cellular site. Herein, we critically evaluate recent findings in the field which illustrate that drebrin E works together with two other actin-binding proteins, namely Arp3 (actin-related protein 3, a component of the Arp2/3 complex that simultaneously controls actin nucleation for polymerization and branching of actin filaments) and Eps8 (epidermal growth factor receptor pathway substrate 8 that controls capping of the barbed ends of actin filaments, as well as actin filament bundling) to regulate the homeostasis of F-actin filament bundles at the ectoplasmic specialization (ES), a testis-specific atypical adherens junction (AJ) in the seminiferous epithelium. This is mediated by the strict temporal and spatial expression of these three actin-binding proteins at the apical and basal ES at the Sertoli cell-spermatid (step 8-19) and Sertoli-Sertoli cell interface, respectively, during the seminiferous epithelial cycle of spermatogenesis. In this Commentary, we put forth a possible model by which drebrin E may be acting as a platform upon which proteins (e.g., Arp3) that are needed to alter the conformation of actin filament bundles at the ES can be recruited to the site, thus facilitating changes in cell shape and cell position in the epithelium during spermiogenesis and spermiation. In short, drebrin E may be acting as a "logistic" distribution center to manage different regulatory proteins at the apical ES, thereby regulating the dynamics of actin filament bundles and modulating the plasticity of the apical ES. This would allow adhesion to be altered continuously throughout the epithelial cycle to accommodate spermatid movement in the seminiferous epithelium during spermiogenesis and spermiation. We also describe a hypothetical model, upon which functional studies can be designed in the future.
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Affiliation(s)
- C Yan Cheng
- Center for Biomedical Research; The Population Council; New York, NY USA
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22
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Oyanagi M, Kaneko K, Kaneko Y, Sasaki M, Nishida C, Matsuda Y, Mitsui T. Proteomic analysis of Nipponia nippon (ID#162). Anim Sci J 2014; 85:814-32. [PMID: 24961376 DOI: 10.1111/asj.12214] [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: 12/08/2013] [Accepted: 01/28/2014] [Indexed: 11/28/2022]
Abstract
We investigated the proteome of a female Crested Ibis (Nipponia nippon, ID#162) that died on March 10, 2010 at the Sado Japanese Crested Ibis Conservation Center. Protein preparations from the brain, trachea, liver, heart, lung, proventriculus, muscular stomach, small intestine, duodenum, ovary and neck muscle were subjected to in-solution shotgun mass spectrometry (MS)/MS analyses using an LTQ Orbitrap XL mass spectrometer. A search of the National Center for Biotechnology Information Gallus gallus databases revealed 4253 GI (GenInfo Identifier) numbers with the sum of the same 11 tissues examined in the Crested Ibis. To interpret the obtained proteomics data, it was verified in detail with the data obtained from the brain of the Crested Ibis. It has been reported that drebrin A is specifically expressed in adult chicken brain. In the shotgun proteomic analyses of the Crested Ibis, we identified drebrin A as a brain-specific protein. Furthermore, Western blotting analysis of the protein preparations from 10 tissues of the Crested Ibis and 150-day-old hens using anti-drebrin antibodies showed intensive expression of approximately 110 kDa polypeptides of drebrin in both brains. We believe firmly that the present data will contribute to initial and fundamental steps toward understanding the Crested Ibis proteome.
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Affiliation(s)
- Mitsuru Oyanagi
- Genome Research Center, Faculty of Agriculture, Niigata University, Niigata, Japan; Graduate School of Science and Technology, Niigata University, Niigata, Japan; Center for Toki and Ecological Restoration, Niigata University, Niigata, Japan
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23
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Ao X, Liu Y, Qin M, Li C, Chen X, Xiao L, Liu J. Expression of Dbn1 during mouse brain development and neural stem cell differentiation. Biochem Biophys Res Commun 2014; 449:81-7. [PMID: 24814707 DOI: 10.1016/j.bbrc.2014.04.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 04/29/2014] [Indexed: 11/25/2022]
Abstract
Dbn1 is a newly discovered gene in the drebrin gene family of mice. Previous studies have reported that Dbn1 is specifically expressed in the mouse brain suggesting its potential role in brain development. However, a detailed analysis of Dbn1 expression during mouse brain development has not been demonstrated. Here, we describe the expression pattern of Dbn1 and the coexpression of Dbn1 and actin during the development of the mouse brain from embryonic day 14 (E14) to adulthood and during the differentiation of neural stem cells (NSCs), as determined using immunohistochemistry, double-labeling immunofluorescence, and quantitative real-time polymerase chain reaction. During mouse brain development, Dbn1 expression level was high at E14, attenuated postnatally, reached its highest point at postnatal day 7 (P7), and showed a very low level at adulthood. Imaging data showed that Dbn1 was mainly expressed in the hippocampus, ventricular zone, and cortex, where NSCs are densely distributed, and that the intracellular distribution of Dbn1 was predominantly located in the cytoplasm edges and neurites. Moreover, the signal for colocalization of Dbn1 with actin was intense at E14, P0, and P7, but it was weak at adulthood. During NSC differentiation, Dbn1 mRNA expression increased after the onset of differentiation and reached its highest point at 3days, followed by a decrease in expression. The imaging data showed that Dbn1 was increasingly expressed in the extending neurites in accordance with the cell morphological changes that occur during differentiation. Furthermore, obvious colocalization signals of Dbn1 with actin were found in the neurites and dendritic spines. Collectively, these results suggest that Dbn1 may play a key role in mouse brain development and may regulate NSC differentiation by filamentous actin.
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Affiliation(s)
- Xiang Ao
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China; The Battalion 5 of Cadet Brigade, PLA, Third Military Medical University, Chongqing 400038, China
| | - Yunlai Liu
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China
| | - Maolin Qin
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China
| | - Chengren Li
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China
| | - Xingshu Chen
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China
| | - Lan Xiao
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China
| | - Jianjun Liu
- Department of Histology and Embryology, PLA, Third Military Medical University, Chongqing 400038, China.
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24
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Yamazaki H, Kojima N, Kato K, Hirose E, Iwasaki T, Mizui T, Takahashi H, Hanamura K, Roppongi RT, Koibuchi N, Sekino Y, Mori N, Shirao T. Spikar, a novel drebrin-binding protein, regulates the formation and stabilization of dendritic spines. J Neurochem 2013; 128:507-22. [PMID: 24117785 DOI: 10.1111/jnc.12486] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/01/2023]
Abstract
Dendritic spines are small, actin-rich protrusions on dendrites, the development of which is fundamental for the formation of neural circuits. The actin cytoskeleton is central to dendritic spine morphogenesis. Drebrin is an actin-binding protein that is thought to initiate spine formation through a unique drebrin-actin complex at postsynaptic sites. However drebrin overexpression in neurons does not increase the final density of dendritic spines. In this study, we have identified and characterized a novel drebrin-binding protein, spikar. Spikar is localized in cell nuclei and dendritic spines, and accumulation of spikar in dendritic spines directly correlates with spine density. A reporter gene assay demonstrated that spikar acts as a transcriptional co-activator for nuclear receptors. We found that dendritic spine, but not nuclear, localization of spikar requires drebrin. RNA-interference knockdown and overexpression experiments demonstrated that extranuclear spikar regulates dendritic spine density by modulating de novo spine formation and retraction of existing spines. Unlike drebrin, spikar does not affect either the morphology or function of dendritic spines. These findings indicate that drebrin-mediated postsynaptic accumulation of spikar regulates spine density, but is not involved in regulation of spine morphology.
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Affiliation(s)
- Hiroyuki Yamazaki
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
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25
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Worth DC, Daly CN, Geraldo S, Oozeer F, Gordon-Weeks PR. Drebrin contains a cryptic F-actin-bundling activity regulated by Cdk5 phosphorylation. ACTA ACUST UNITED AC 2013; 202:793-806. [PMID: 23979715 PMCID: PMC3760615 DOI: 10.1083/jcb.201303005] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Drebrin activity in F-actin bundling and filopodia induction relies on two adjacent F-actin binding sites and a Cdk5 phosphorylation-regulated intramolecular inhibitory interaction. Drebrin is an actin filament (F-actin)–binding protein with crucial roles in neuritogenesis and synaptic plasticity. Drebrin couples dynamic microtubules to F-actin in growth cone filopodia via binding to the microtubule-binding +TIP protein EB3 and organizes F-actin in dendritic spines. Precisely how drebrin interacts with F-actin and how this is regulated is unknown. We used cellular and in vitro assays with a library of drebrin deletion constructs to map F-actin binding sites. We discovered two domains in the N-terminal half of drebrin—a coiled-coil domain and a helical domain—that independently bound to F-actin and cooperatively bundled F-actin. However, this activity was repressed by an intramolecular interaction relieved by Cdk5 phosphorylation of serine 142 located in the coiled-coil domain. Phospho-mimetic and phospho-dead mutants of serine 142 interfered with neuritogenesis and coupling of microtubules to F-actin in growth cone filopodia. These findings show that drebrin contains a cryptic F-actin–bundling activity regulated by phosphorylation and provide a mechanistic model for microtubule–F-actin coupling.
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Affiliation(s)
- Daniel C Worth
- Medical Research Council MRC Centre for Developmental Neurobiology, King's College London, London SE1 1UL, England, UK
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26
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Ditlev JA, Mayer BJ, Loew LM. There is more than one way to model an elephant. Experiment-driven modeling of the actin cytoskeleton. Biophys J 2013; 104:520-32. [PMID: 23442903 DOI: 10.1016/j.bpj.2012.12.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 12/20/2012] [Accepted: 12/21/2012] [Indexed: 10/27/2022] Open
Abstract
Mathematical modeling has established its value for investigating the interplay of biochemical and mechanical mechanisms underlying actin-based motility. Because of the complex nature of actin dynamics and its regulation, many of these models are phenomenological or conceptual, providing a general understanding of the physics at play. But the wealth of carefully measured kinetic data on the interactions of many of the players in actin biochemistry cries out for the creation of more detailed and accurate models that could permit investigators to dissect interdependent roles of individual molecular components. Moreover, no human mind can assimilate all of the mechanisms underlying complex protein networks; so an additional benefit of a detailed kinetic model is that the numerous binding proteins, signaling mechanisms, and biochemical reactions can be computationally organized in a fully explicit, accessible, visualizable, and reusable structure. In this review, we will focus on how comprehensive and adaptable modeling allows investigators to explain experimental observations and develop testable hypotheses on the intracellular dynamics of the actin cytoskeleton.
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Affiliation(s)
- Jonathon A Ditlev
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, Connecticut, USA
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27
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Shirao T, González-Billault C. Actin filaments and microtubules in dendritic spines. J Neurochem 2013; 126:155-64. [PMID: 23692384 DOI: 10.1111/jnc.12313] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/13/2013] [Accepted: 05/13/2013] [Indexed: 01/26/2023]
Abstract
Dendritic spines are small protrusions emerging from their parent dendrites, and their morphological changes are involved in synaptic plasticity. These tiny structures are composed of thousands of different proteins belonging to several subfamilies such as membrane receptors, scaffold proteins, signal transduction proteins, and cytoskeletal proteins. Actin filaments in dendritic spines consist of double helix of actin protomers decorated with drebrin and ADF/cofilin, and the balance of the two is closely related to the actin dynamics, which may govern morphological and functional synaptic plasticity. During development, the accumulation of drebrin-binding type actin filaments is one of the initial events occurring at the nascent excitatory postsynaptic site, and plays a pivotal role in spine formation as well as small GTPases. It has been recently reported that microtubules transiently appear in dendritic spines in correlation with synaptic activity. Interestingly, it is suggested that microtubule dynamics might couple with actin dynamics. In this review, we will summarize the contribution of both actin filaments and microtubules to the formation and regulation of dendritic spines, and further discuss the role of cytoskeletal deregulation in neurological disorders.
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Affiliation(s)
- Tomoaki Shirao
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan.
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28
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Shirai K, Mizui T, Suzuki Y, Okamoto M, Hanamura K, Yoshida Y, Hino M, Noda SE, Al-jahdari WS, Chakravarti A, Shirao T, Nakano T. X Irradiation Changes Dendritic Spine Morphology and Density through Reduction of Cytoskeletal Proteins in Mature Neurons. Radiat Res 2013; 179:630-6. [DOI: 10.1667/rr3098.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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29
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Roppongi RT, Kojima N, Hanamura K, Yamazaki H, Shirao T. Selective reduction of drebrin and actin in dendritic spines of hippocampal neurons by activation of 5-HT(2A) receptors. Neurosci Lett 2013; 547:76-81. [PMID: 23684573 DOI: 10.1016/j.neulet.2013.04.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 01/10/2023]
Abstract
Abnormal architecture of dendritic spines is associated with neurodevelopmental and neurodegenerative diseases. The 5-HT(2A) receptor is a potential therapeutic target for mental illnesses and it is functionally and genetically associated with many types of psychiatric disorders. It has been reported that 5-HT(2A) receptor activation alters spine architecture. Although actin cytoskeleton has a key role in the regulation of spine architecture, it is not clarified whether 5-HT(2A)+ receptor activation affect the actin cytoskeleton in dendritic spines. In the present study, we examined the effect of 5-HT(2A) receptor activation on the actin cytoskeleton in dendritic spines of mature hippocampal neurons in low-density culture. Immunocytochemical analysis showed that 15 min exposure of 5-HT(2A) receptor agonist (±)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) significantly decreased the cluster densities of drebrin (control, 37.0±6.9 per 100 μm, DOI, 12.5±2.9) and F-actin (control, 18.3±4.9; DOI, 7.7±2.1) at dendritic spines without any detectable changes in the cluster densities of synapsin I and PSD-95. At the same time period DOI exposure did not affect spine architecture (spine density: control, 38.3±5.1 per 100 μm; DOI, 25.6±3.5; spine length: control, 1.99±0.18; DOI, 2.00±0.29; spine width: control, 0.72±0.06; DOI, 0.77±0.11). Thus, it is indicated that decrease of drebrin and F-actin can occur at the dendritic spines without morphological changes. Together our data suggest that 5-HT(2A) receptors activation is involved in the regulation of distribution of cytoskeleton in the dendritic spines.
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Affiliation(s)
- Reiko T Roppongi
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Japan
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30
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Su W, Mruk DD, Cheng CY. Regulation of actin dynamics and protein trafficking during spermatogenesis--insights into a complex process. Crit Rev Biochem Mol Biol 2013; 48:153-72. [PMID: 23339542 DOI: 10.3109/10409238.2012.758084] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the mammalian testis, extensive restructuring takes place across the seminiferous epithelium at the Sertoli-Sertoli and Sertoli-germ cell interface during the epithelial cycle of spermatogenesis, which is important to facilitate changes in the cell shape and morphology of developing germ cells. However, precise communications also take place at the cell junctions to coordinate the discrete events pertinent to spermatogenesis, namely spermatogonial renewal via mitosis, cell cycle progression and meiosis, spermiogenesis and spermiation. It is obvious that these cellular events are intimately related to the underlying actin-based cytoskeleton which is being used by different cell junctions for their attachment. However, little is known on the biology and regulation of this cytoskeleton, in particular its possible involvement in endocytic vesicle-mediated trafficking during spermatogenesis, which in turn affects cell adhesive function and communication at the cell-cell interface. Studies in other epithelia in recent years have shed insightful information on the intimate involvement of actin dynamics and protein trafficking in regulating cell adhesion and communications. The goal of this critical review is to provide an updated assessment of the latest findings in the field on how these complex processes are being regulated during spermatogenesis. We also provide a working model based on the latest findings in the field including our laboratory to provide our thoughts on an apparent complicated subject, which also serves as the framework for investigators in the field. It is obvious that this model will be rapidly updated when more data are available in future years.
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Affiliation(s)
- Wenhui Su
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY 10065, USA
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31
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Abstract
Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite current advances in therapy consisting of surgery followed by chemotherapy and radiation, the overall survival rate still remains poor. Therapeutic failures are partly attributable to the highly infiltrative nature of tumor adjacent to normal brain parenchyma. Recently, evidence is mounting to suggest that actin cytoskeleton dynamics are critical components of the cell invasion process. Drebrin is an actin-binding protein involved in the regulation of actin filament organization, and plays a significant role in cell motility; however, the role of drebrin in glioma cell invasiveness has not yet been fully elucidated. Therefore, this study was aimed to clarify the role of drebrin in glioma cell morphology and cell motility. Here we show that drebrin is expressed in glioma cell lines and in operative specimens of GBM. We demonstrate that stable overexpression of drebrin in U87 cells leads to alterations in cell morphology, and induces increased invasiveness in vitro while knockdown of drebrin in U87 cells by small interfering RNA (siRNA) decreases invasion and migration. In addition, we show that depletion of drebrin by siRNA alters glioma cell morphology in A172 GBM cell line. Our results suggest that drebrin contributes to the maintenance of cell shape, and may play an important role in glioma cell motility.
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32
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Dun XP, Bandeira de Lima T, Allen J, Geraldo S, Gordon-Weeks P, Chilton JK. Drebrin controls neuronal migration through the formation and alignment of the leading process. Mol Cell Neurosci 2012; 49:341-50. [PMID: 22306864 PMCID: PMC3356577 DOI: 10.1016/j.mcn.2012.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 01/16/2012] [Accepted: 01/18/2012] [Indexed: 12/18/2022] Open
Abstract
Formation of a functional nervous system requires neurons to migrate to the correct place within the developing brain. Tangentially migrating neurons are guided by a leading process which extends towards the target and is followed by the cell body. How environmental cues are coupled to specific cytoskeletal changes to produce and guide leading process growth is unknown. One such cytoskeletal modulator is drebrin, an actin-binding protein known to induce protrusions in many cell types and be important for regulating neuronal morphology. Using the migration of oculomotor neurons as a model, we have shown that drebrin is necessary for the generation and guidance of the leading process. In the absence of drebrin, leading processes are not formed and cells fail to migrate although axon growth and pathfinding appear grossly unaffected. Conversely, when levels of drebrin are elevated the leading processes turn away from their target and as a result the motor neuron cell bodies move along abnormal paths within the brain. The aberrant trajectories were highly reproducible suggesting that drebrin is required to interpret specific guidance cues. The axons and growth cones of these neurons display morphological changes, particularly increased branching and filopodial number but despite this they extend along normal developmental pathways. Collectively these results show that drebrin is initially necessary for the formation of a leading process and subsequently for this to respond to navigational signals and grow in the correct direction. Furthermore, we have shown that the actions of drebrin can be segregated within individual motor neurons to direct their migration independently of axon guidance.
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Affiliation(s)
- Xin-peng Dun
- Institute of Biomedical and Clinical Science, Peninsula Medical School, University of Exeter, Research Way, Plymouth PL6 8BU, UK
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33
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VanGuilder HD, Farley JA, Yan H, Van Kirk CA, Mitschelen M, Sonntag WE, Freeman WM. Hippocampal dysregulation of synaptic plasticity-associated proteins with age-related cognitive decline. Neurobiol Dis 2011; 43:201-12. [PMID: 21440628 DOI: 10.1016/j.nbd.2011.03.012] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 03/18/2011] [Indexed: 12/16/2022] Open
Abstract
Age-related cognitive decline occurs without frank neurodegeneration and is the most common cause of memory impairment in aging individuals. With increasing longevity, cognitive deficits, especially in hippocampus-dependent memory processes, are increasing in prevalence. Nevertheless, the neurobiological basis of age-related cognitive decline remains unknown. While concerted efforts have led to the identification of neurobiological changes with aging, few age-related alterations have been definitively correlated to behavioral measures of cognitive decline. In this work, adult (12 months) and aged (28 months) rats were categorized by Morris water maze performance as Adult cognitively Intact, Aged cognitively Intact or Aged cognitively Impaired, and protein expression was examined in hippocampal synaptosome preparations. Previously described differences in synaptic expression of neurotransmission-associated proteins (Dnm1, Hpca, Stx1, Syn1, Syn2, Syp, SNAP25, VAMP2 and 14-3-3 eta, gamma, and zeta) were confirmed between Adult and Aged rats, with no further dysregulation associated with cognitive impairment. Proteins related to synaptic structural stability (MAP2, drebrin, Nogo-A) and activity-dependent signaling (PSD-95, 14-3-3θ, CaMKIIα) were up- and down-regulated, respectively, with cognitive impairment but were not altered with increasing age. Localization of MAP2, PSD-95, and CaMKIIα demonstrated protein expression alterations throughout the hippocampus. The altered expression of activity- and structural stability-associated proteins suggests that impaired synaptic plasticity is a distinct phenomenon that occurs with age-related cognitive decline, and demonstrates that cognitive decline is not simply an exacerbation of the aging phenotype.
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Affiliation(s)
- Heather D VanGuilder
- Penn State College of Medicine, Department of Pharmacology, Hershey Center for Applied Research, 500 University Drive, Hershey, PA 17033, USA
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Pérez-Martínez M, Gordón-Alonso M, Cabrero JR, Barrero-Villar M, Rey M, Mittelbrunn M, Lamana A, Morlino G, Calabia C, Yamazaki H, Shirao T, Vázquez J, González-Amaro R, Veiga E, Sánchez-Madrid F. F-actin-binding protein drebrin regulates CXCR4 recruitment to the immune synapse. J Cell Sci 2010; 123:1160-70. [DOI: 10.1242/jcs.064238] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The adaptive immune response depends on the interaction of T cells and antigen-presenting cells at the immune synapse. Formation of the immune synapse and the subsequent T-cell activation are highly dependent on the actin cytoskeleton. In this work, we describe that T cells express drebrin, a neuronal actin-binding protein. Drebrin colocalizes with the chemokine receptor CXCR4 and F-actin at the peripheral supramolecular activation cluster in the immune synapse. Drebrin interacts with the cytoplasmic tail of CXCR4 and both proteins redistribute to the immune synapse with similar kinetics. Drebrin knockdown in T cells impairs the redistribution of CXCR4 and inhibits actin polymerization at the immune synapse as well as IL-2 production. Our data indicate that drebrin exerts an unexpected and relevant functional role in T cells during the generation of the immune response.
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Affiliation(s)
- Manuel Pérez-Martínez
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Mónica Gordón-Alonso
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
- Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain
| | - José Román Cabrero
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Marta Barrero-Villar
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Mercedes Rey
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - María Mittelbrunn
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Amalia Lamana
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Giulia Morlino
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Carmen Calabia
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
| | - Hiroyuki Yamazaki
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Tomoaki Shirao
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Jesús Vázquez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | | | - Esteban Veiga
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
- Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain
| | - Francisco Sánchez-Madrid
- Servicio de Inmunología, Hospital Universitario de la Princesa, Diego de León, 62, 28006, Madrid, Spain
- Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain
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Johnson HW, Schell MJ. Neuronal IP3 3-kinase is an F-actin-bundling protein: role in dendritic targeting and regulation of spine morphology. Mol Biol Cell 2010; 20:5166-80. [PMID: 19846664 DOI: 10.1091/mbc.e09-01-0083] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The actin microstructure in dendritic spines is involved in synaptic plasticity. Inositol trisphosphate 3-kinase A (ITPKA) terminates Ins(1,4,5)P(3) signals emanating from spines and also binds filamentous actin (F-actin) through its amino terminal region (amino acids 1-66, N66). Here we investigated how ITPKA, independent of its kinase activity, regulates dendritic spine F-actin microstructure. We show that the N66 region of the protein mediates F-actin bundling. An N66 fusion protein bundled F-actin in vitro, and the bundling involved N66 dimerization. By mutagenesis we identified a point mutation in a predicted helical region that eliminated both F-actin binding and bundling, rendering the enzyme cytosolic. A fusion protein containing a minimal helical region (amino acids 9-52, N9-52) bound F-actin in vitro and in cells, but had lower affinity. In hippocampal neurons, GFP-tagged N66 expression was highly polarized, with targeting of the enzyme predominantly to spines. By contrast, N9-52-GFP expression occurred in actin-rich structures in dendrites and growth cones. Expression of N66-GFP tripled the length of dendritic protrusions, induced longer dendritic spine necks, and induced polarized actin motility in time-lapse assays. These results suggest that, in addition to its ability to regulate intracellular Ca(2+) via Ins(1,4,5)P(3) metabolism, ITPKA regulates structural plasticity.
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Affiliation(s)
- Hong W Johnson
- Department of Pharmacology, Uniformed Services University, Bethesda, MD 20814, USA
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36
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Saha S, Mundia MM, Zhang F, Demers RW, Korobova F, Svitkina T, Perieteanu AA, Dawson JF, Kashina A. Arginylation regulates intracellular actin polymer level by modulating actin properties and binding of capping and severing proteins. Mol Biol Cell 2010; 21:1350-61. [PMID: 20181827 PMCID: PMC2854093 DOI: 10.1091/mbc.e09-09-0829] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Actin arginylation regulates lamella formation in motile fibroblasts, but the underlying molecular mechanisms are unknown. To understand how arginylation affects the actin cytoskeleton, we investigated the biochemical properties and the structural organization of actin filaments in wild-type and arginyltransferase (Ate1) knockout cells. We found that Ate1 knockout results in a dramatic reduction of the actin polymer levels in vivo accompanied by a corresponding increase in the monomer level. Purified nonarginylated actin has altered polymerization properties, and actin filaments from Ate1 knockout cells show altered interactions with several associated proteins. Ate1 knockout cells have severe impairment of cytoskeletal organization throughout the cell. Thus, arginylation regulates the ability of actin to form filaments in the whole cell rather than preventing the collapse of preformed actin networks at the cell leading edge as proposed in our previous model. This regulation is achieved through interconnected mechanisms that involve actin polymerization per se and through binding of actin-associated proteins.
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Affiliation(s)
- Sougata Saha
- Department of Animal Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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37
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Mercer JC, Qi Q, Mottram LF, Law M, Bruce D, Iyer A, Morales JL, Yamazaki H, Shirao T, Peterson BR, August A. Chemico-genetic identification of drebrin as a regulator of calcium responses. Int J Biochem Cell Biol 2009; 42:337-45. [PMID: 19948240 DOI: 10.1016/j.biocel.2009.11.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 11/09/2009] [Accepted: 11/23/2009] [Indexed: 01/11/2023]
Abstract
Store-operated calcium channels are plasma membrane Ca(2+) channels that are activated by depletion of intracellular Ca(2+) stores, resulting in an increase in intracellular Ca(2+) concentration, which is maintained for prolonged periods in some cell types. Increases in intracellular Ca(2+) concentration serve as signals that activate a number of cellular processes, however, little is known about the regulation of these channels. We have characterized the immuno-suppressant compound BTP, which blocks store-operated channel mediated calcium influx into cells. Using an affinity purification scheme to identify potential targets of BTP, we identified the actin reorganizing protein, drebrin, and demonstrated that loss of drebrin protein expression prevents store-operated channel mediated Ca(2+) entry, similar to BTP treatment. BTP also blocks actin rearrangements induced by drebrin. While actin cytoskeletal reorganization has been implicated in store-operated calcium channel regulation, little is known about actin-binding proteins that are involved in this process, or how actin regulates channel function. The identification of drebrin as a mediator of this process should provide new insight into the interaction between actin rearrangement and store-operated channel mediated calcium influx.
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Affiliation(s)
- Jason C Mercer
- Center for Molecular Immunology & Infectious Disease, Department of Veterinary & Biomedical Science, The Pennsylvania State University, University Park, PA 16802, USA
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Pontrello CG, Ethell IM. Accelerators, Brakes, and Gears of Actin Dynamics in Dendritic Spines. ACTA ACUST UNITED AC 2009; 3:67-86. [PMID: 20463852 DOI: 10.2174/1874082000903020067] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dendritic spines are actin-rich structures that accommodate the postsynaptic sites of most excitatory synapses in the brain. Although dendritic spines form and mature as synaptic connections develop, they remain plastic even in the adult brain, where they can rapidly grow, change, or collapse in response to normal physiological changes in synaptic activity that underlie learning and memory. Pathological stimuli can adversely affect dendritic spine shape and number, and this is seen in neurodegenerative disorders and some forms of mental retardation and autism as well. Many of the molecular signals that control these changes in dendritic spines act through the regulation of filamentous actin (F-actin), some through direct interaction with actin, and others via downstream effectors. For example, cortactin, cofilin, and gelsolin are actin-binding proteins that directly regulate actin dynamics in dendritic spines. Activities of these proteins are precisely regulated by intracellular signaling events that control their phosphorylation state and localization. In this review, we discuss how actin-regulating proteins maintain the balance between F-actin assembly and disassembly that is needed to stabilize mature dendritic spines, and how changes in their activities may lead to rapid remodeling of dendritic spines.
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Affiliation(s)
- Crystal G Pontrello
- Biomedical Sciences Division and Neuroscience program, University of California Riverside, USA
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39
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Takahashi H, Yamazaki H, Hanamura K, Sekino Y, Shirao T. Activity of the AMPA receptor regulates drebrin stabilization in dendritic spine morphogenesis. J Cell Sci 2009; 122:1211-9. [DOI: 10.1242/jcs.043729] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Spine morphogenesis mainly occurs during development as a morphological shift from filopodia-like thin protrusions to bulbous ones. We have previously reported that synaptic clustering of the actin-binding protein drebrin in dendritic filopodia governs spine morphogenesis and synaptic PSD-95 clustering. Here, we report the activity-dependent cellular mechanisms for spine morphogenesis, in which the activity of AMPA receptors (AMPARs) regulates drebrin clustering in spines by promoting drebrin stabilization. In cultured developing hippocampal neurons, pharmacological blockade of AMPARs, but not of other glutamate receptors, suppressed postsynaptic drebrin clustering without affecting presynaptic clustering of synapsin I (synapsin-1). Conversely, the enhancement of the action of AMPARs promoted drebrin clustering in spines. When we explored drebrin dynamics by photobleaching individual spines, we found that AMPAR activity increased the fraction of stable drebrin without affecting the time constant of drebrin turnover. An increase in the fraction of stable drebrin corresponded with increased drebrin clustering. AMPAR blockade also suppressed normal morphological maturation of spines and synaptic PSD-95 clustering in spines. Together, these data suggest that AMPAR-mediated stabilization of drebrin in spines is an activity-dependent cellular mechanism for spine morphogenesis.
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Affiliation(s)
- Hideto Takahashi
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
- ERCGSM, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Hiroyuki Yamazaki
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Kenji Hanamura
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Yuko Sekino
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
- CREST, JST, Kawaguchi, Saitama, 332-0012, Japan
- Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, 1108-8639, Japan
| | - Tomoaki Shirao
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
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40
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Ivanov A, Esclapez M, Pellegrino C, Shirao T, Ferhat L. Drebrin A regulates dendritic spine plasticity and synaptic function in mature cultured hippocampal neurons. J Cell Sci 2009; 122:524-34. [PMID: 19174472 DOI: 10.1242/jcs.033464] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drebrin A, one of the most abundant neuron-specific F-actin-binding proteins, is found exclusively in dendrites and is particularly concentrated in dendritic spines receiving excitatory inputs. We investigated the role of drebrin A in synaptic transmission and found that overexpression of drebrin A augmented the glutamatergic synaptic transmission, probably through an increase of active synaptic site density. Interestingly, overexpression of drebrin A also affected the frequency, amplitude and kinetics of miniature inhibitory postsynaptic currents (mIPSCs), despite the fact that GABAergic synapse density and transmission efficacy were not modified. Downregulation of drebrin A led to a decrease of both glutamatergic and GABAergic synaptic activity. In heterologous cells, drebrin A reorganized and stabilized F-actin and these effects were mediated by its actin-binding domain. Thus, drebrin A might regulate dendritic spine morphology via regulation of actin cytoskeleton remodeling and dynamics. Our data demonstrate for the first time that drebrin A modulates glutamatergic and GABAergic synaptic activities.
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Affiliation(s)
- Anton Ivanov
- INMED/INSERM U29, Parc Scientifique de Luminy, 13273, Marseille, France
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41
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Lin WH, Webb DJ. Actin and Actin-Binding Proteins: Masters of Dendritic Spine Formation, Morphology, and Function. THE OPEN NEUROSCIENCE JOURNAL 2009; 3:54-66. [PMID: 20717495 PMCID: PMC2921857 DOI: 10.2174/1874082000903020054] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dendritic spines are actin-rich protrusions that comprise the postsynaptic sites of synapses and receive the majority of excitatory synaptic inputs in the central nervous system. These structures are central to cognitive processes, and alterations in their number, size, and morphology are associated with many neurological disorders. Although the actin cytoskeleton is thought to govern spine formation, morphology, and synaptic functions, we are only beginning to understand how modulation of actin reorganization by actin-binding proteins (ABPs) contributes to the function of dendritic spines and synapses. In this review, we discuss what is currently known about the role of ABPs in regulating the formation, morphology, motility, and plasticity of dendritic spines and synapses.
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Affiliation(s)
- Wan-Hsin Lin
- Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Donna J. Webb
- Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37235, USA
- Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee 37235, USA
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42
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Song M, Kojima N, Hanamura K, Sekino Y, Inoue H, Mikuni M, Shirao T. Expression of drebrin E in migrating neuroblasts in adult rat brain: Coincidence between drebrin E disappearance from cell body and cessation of migration. Neuroscience 2008; 152:670-82. [DOI: 10.1016/j.neuroscience.2007.10.068] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 09/16/2007] [Accepted: 02/01/2008] [Indexed: 12/12/2022]
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Sekino Y, Kojima N, Shirao T. Role of actin cytoskeleton in dendritic spine morphogenesis. Neurochem Int 2007; 51:92-104. [PMID: 17590478 DOI: 10.1016/j.neuint.2007.04.029] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 04/25/2007] [Accepted: 04/27/2007] [Indexed: 11/20/2022]
Abstract
Dendritic spines are the postsynaptic receptive regions of most excitatory synapses, and their morphological plasticity play a pivotal role in higher brain functions, such as learning and memory. The dynamics of spine morphology is due to the actin cytoskeleton concentrated highly in spines. Filopodia, which are thin and headless protrusions, are thought to be precursors of dendritic spines. Drebrin, a spine-resident side-binding protein of filamentous actin (F-actin), is responsible for recruiting F-actin and PSD-95 into filopodia, and is suggested to govern spine morphogenesis. Interestingly, some recent studies on neurological disorders accompanied by cognitive deficits suggested that the loss of drebrin from dendritic spines is a common pathognomonic feature of synaptic dysfunction. In this review, to understand the importance of actin-binding proteins in spine morphogenesis, we first outline the well-established knowledge pertaining to the actin cytoskeleton in non-neuronal cells, such as the mechanism of regulation by small GTPases, the equilibrium between globular actin (G-actin) and F-actin, and the distinct roles of various actin-binding proteins. Then, we review the dynamic changes in the localization of drebrin during synaptogenesis and in response to glutamate receptor activation. Because side-binding proteins are located upstream of the regulatory pathway for actin organization via other actin-binding proteins, we discuss the significance of drebrin in the regulatory mechanism of spine morphology through the reorganization of the actin cytoskeleton. In addition, we discuss the possible involvement of an actin-myosin interaction in the morphological plasticity of spines.
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Affiliation(s)
- Yuko Sekino
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
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44
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Majoul I, Shirao T, Sekino Y, Duden R. Many faces of drebrin: from building dendritic spines and stabilizing gap junctions to shaping neurite-like cell processes. Histochem Cell Biol 2007; 127:355-61. [PMID: 17285341 DOI: 10.1007/s00418-007-0273-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2007] [Indexed: 01/03/2023]
Abstract
In this review we consider the multiple functions of developmentally regulated brain protein (drebrin), an actin-binding protein, in the formation of cellular polarity in different cell types. Drebrin has a well-established role in the morphogenesis, patterning and maintenance of dendritic spines in neurons. We have recently shown that drebrin also stabilizes Connexin-43 containing gap junctions at the plasma membrane. The latest literature and our own data suggest that drebrin may be broadly involved in shaping cell processes and in the formation of stabilized plasma membrane domains, an effect that is likely to be of crucial significance for formation of cell polarity in both neuronal and non-neuronal types.
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Affiliation(s)
- Irina Majoul
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK.
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45
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Sekino Y, Tanaka S, Hanamura K, Yamazaki H, Sasagawa Y, Xue Y, Hayashi K, Shirao T. Activation of N-methyl-d-aspartate receptor induces a shift of drebrin distribution: Disappearance from dendritic spines and appearance in dendritic shafts. Mol Cell Neurosci 2006; 31:493-504. [PMID: 16368245 DOI: 10.1016/j.mcn.2005.11.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Revised: 10/27/2005] [Accepted: 11/03/2005] [Indexed: 11/18/2022] Open
Abstract
Drebrin is a major actin-filament-binding protein localized in mature dendritic spines. A recent in vivo immunoelectron microscopic study suggests that drebrin content at each dendritic spine is regulated by some unknown mechanisms. In the present in vitro study, we examined whether glutamate stimulation alters drebrin content in dendritic spines. Glutamate stimulation induced disappearance of drebrin immunostaining from dendritic spines but led to appearance of drebrin immunostaining in dendritic shafts and somata. The glutamate-induced shift of drebrin immunostaining was blocked by an NMDA receptor antagonist. Immunoblot analyses showed that both the total and the cytosolic drebrin remained unchanged and revealed that the drebrin shift was not due to drebrin degradation. These findings indicate that NMDA receptor activation induces a shift in subcellular distribution of drebrin associated with actin filaments, and that the shift might be a molecular basis for actin reorganization accompanied with synaptic plasticity.
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Affiliation(s)
- Yuko Sekino
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
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46
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Mizui T, Takahashi H, Sekino Y, Shirao T. Overexpression of drebrin A in immature neurons induces the accumulation of F-actin and PSD-95 into dendritic filopodia, and the formation of large abnormal protrusions. Mol Cell Neurosci 2005; 30:149-57. [PMID: 16054392 DOI: 10.1016/j.mcn.2005.06.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 06/11/2005] [Accepted: 06/30/2005] [Indexed: 11/28/2022] Open
Abstract
Drebrin A is a neuron-specific F-actin binding protein, and plays a pivotal role in the spine formation. In this study, we expressed drebrin A tagged with green fluorescent protein (GFP-DA) in hippocampal neurons at 7-9 days in vitro when presynaptic terminals are not fully maturated. GFP-DA was accumulated in dendritic protrusions and formed large abnormal structures. Since these structures were similar to filopodia in terms of lack of MAP2 immunostaining, we named them "megapodia" meaning large dendritic filopodia. F-actin and PSD-95 were also accumulated in megapodia, and their amounts were significantly correlated with that of GFP-DA. However, the expression of GFP-DA did not result in the promotion of the morphological change from filopodia into spines. These results demonstrate that drebrin A accumulates spine-resident proteins via protein-protein interaction in filopodia, and suggest that the spine formation requires the concurrence of the increase of drebrin-A expression and the functional presynaptic contact.
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Affiliation(s)
- Toshiyuki Mizui
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi 371-8511, Japan
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47
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Chew CS, Okamoto CT, Chen X, Thomas R. Drebrin E2 is differentially expressed and phosphorylated in parietal cells in the gastric mucosa. Am J Physiol Gastrointest Liver Physiol 2005; 289:G320-31. [PMID: 15790763 DOI: 10.1152/ajpgi.00002.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Developmentally regulated brain proteins (drebrins) are highly expressed in brain where they may regulate actin filament formation in dendritic spines. Recently, the drebrin E2 isoform was detected in certain epithelial cell types including the gastric parietal cell. In gastric parietal cells, activation of HCl secretion is correlated with actin filament formation and elongation within intracellular canaliculi, which are the sites of acid secretion. The aim of this study was to define the pattern of drebrin expression in gland units in the intact rabbit oxyntic gastric mucosa and to initiate approaches to define the functions of this protein in parietal cells. Drebrin E2 expression was limited entirely or almost entirely to parietal cells and depended upon the localization of parietal cells along the gland axis. Rabbit drebrin E2 was cloned and found to share 86% identity with human drebrin 1a and to possess a number of cross-species conserved protein-protein interaction and phosphorylation consensus sites. Two-dimensional Western blot and phosphoaffinity column analyses confirmed that drebrin is phosphorylated in parietal cells, and several candidate phosphorylation sites were identified by mass spectrometry. Overexpression of epitope-tagged drebrin E2 led to the formation of microspikes and F-actin-rich ring-like structures in cultured parietal cells and suppressed cAMP-dependent acid secretory responses. In Madin-Darby canine kidney cells, coexpression of epitope-tagged drebrin and the Rho family GTPase Cdc42, which induces filopodial extension, produced an additive increase in the length of microspike projections. Coexpression of dominant negative Cdc42 with drebrin E2 did not prevent drebrin-induced microspike formation. These findings suggest that 1) drebrin can induce the formation of F-actin-rich membrane projections by Cdc42-dependent and -independent mechanisms; and that 2) drebrin plays an active role in directing the secretagogue-dependent formation of F-actin-rich filaments on the parietal cell canalicular membrane. Finally, the differential distribution of drebrin in parietal cells along the gland axis suggests that drebrin E2 may be an important marker of parietal cell differentiation and functionality.
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Affiliation(s)
- Catherine S Chew
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Sanders R&E Bldg., Rm. CB 2803, Augusta, GA, USA.
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48
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Aoki C, Sekino Y, Hanamura K, Fujisawa S, Mahadomrongkul V, Ren Y, Shirao T. Drebrin A is a postsynaptic protein that localizes in vivo to the submembranous surface of dendritic sites forming excitatory synapses. J Comp Neurol 2005; 483:383-402. [PMID: 15700273 DOI: 10.1002/cne.20449] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Drebrin A is a neuron-specific, actin binding protein. Evidence to date is from in vitro studies, consistently supporting the involvement of drebrin A in spinogenesis and synaptogenesis. We sought to determine whether drebrin A arrives at the plasma membrane of neurons, in vivo, in time to orchestrate spinogenesis and synaptogenesis. To this end, a new antibody was used to locate drebrin A in relation to electron microscopically imaged synapses during early postnatal days. Western blotting showed that drebrin A emerges at postnatal day (PNd) 6 and becomes progressively more associated with F-actin in the pellet fraction. Light microscopy showed high concentrations of drebrin A in the synaptic layers of the hippocampus and cortex. Electron microscopy revealed that drebrin A in these regions is located exclusively in dendrites both neonatally and in adulthood. In adulthood, nearly all of the synaptic drebrin A is within spines forming asymmetric excitatory synapses, verified by gamma-aminobutyric acid (GABA) negativity. At PNd7, patches of drebrin A immunoreactivity were discretely localized to the submembranous surfaces of dendrites forming slight protrusions-protospines. The drebrin A sites exhibited only thin postsynaptic densities and lacked axonal associations or were contacted by axons that contained only a few vesicles. Yet, because of their immunoreactivity to the NR2B subunit of N-methyl-D-aspartate receptors and immunonegativity of axon terminals to GABA, these could be presumed to be nascent, excitatory synapses. Thus, drebrin A may be involved in organizing the dendritic pool of actin for the formation of spines and of axospinous excitatory synapses during early postnatal periods.
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Affiliation(s)
- Chiye Aoki
- Center for Neural Science, New York University, New York, New York 10003, USA.
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Ethell IM, Pasquale EB. Molecular mechanisms of dendritic spine development and remodeling. Prog Neurobiol 2005; 75:161-205. [PMID: 15882774 DOI: 10.1016/j.pneurobio.2005.02.003] [Citation(s) in RCA: 264] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Revised: 01/28/2005] [Accepted: 02/22/2005] [Indexed: 12/19/2022]
Abstract
Dendritic spines are small protrusions that cover the surface of dendrites and bear the postsynaptic component of excitatory synapses. Having an enlarged head connected to the dendrite by a narrow neck, dendritic spines provide a postsynaptic biochemical compartment that separates the synaptic space from the dendritic shaft and allows each spine to function as a partially independent unit. Spines develop around the time of synaptogenesis and are dynamic structures that continue to undergo remodeling over time. Changes in spine morphology and density influence the properties of neural circuits. Our knowledge of the structure and function of dendritic spines has progressed significantly since their discovery over a century ago, but many uncertainties still remain. For example, several different models have been put forth outlining the sequence of events that lead to the genesis of a spine. Although spines are small and apparently simple organelles with a cytoskeleton mainly composed of actin filaments, regulation of their morphology and physiology appears to be quite sophisticated. A multitude of molecules have been implicated in dendritic spine development and remodeling, suggesting that intricate networks of interconnected signaling pathways converge to regulate actin dynamics in spines. This complexity is not surprising, given the likely importance of dendritic spines in higher brain functions. In this review, we discuss the molecules that are currently known to mediate the exquisite sensitivity of spines to perturbations in their environment and we outline how these molecules interface with each other to mediate cascades of signals flowing from the spine surface to the actin cytoskeleton.
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Affiliation(s)
- Iryna M Ethell
- Division of Biomedical Sciences, University of California Riverside, Riverside, CA 92521, USA
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Kobayashi R, Sekino Y, Shirao T, Tanaka S, Ogura T, Inada K, Saji M. Antisense knockdown of drebrin A, a dendritic spine protein, causes stronger preference, impaired pre-pulse inhibition, and an increased sensitivity to psychostimulant. Neurosci Res 2004; 49:205-17. [PMID: 15140563 DOI: 10.1016/j.neures.2004.02.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Accepted: 02/25/2004] [Indexed: 11/20/2022]
Abstract
Drebrin located in dendritic spines regulates their morphological changes and plays a role in the synaptic plasticity via spine function. Reduced drebrin has been found in the brain of patients with Alzheimer's disease or Down's syndrome. To examine whether the down-regulation of drebrin protein levels causes deficits in higher brain function, such as memory or cognition, we performed antisense-induced knockdown of drebrin A expression in rat brain using an hemagglutinating virus of Japan (HVJ)-liposome gene transfer technique. We investigated the effects of drebrin in vivo knockdown on spatial memory in a water-maze task, sensorimotor gating in a pre-pulse-inhibition test, adaptive behaviors in an open-field test, and sensitivity to psychostimulant in an amphetamine-induced locomotor response. Rats with drebrin A in vivo knockdown displayed a stronger preference for a previous event due to perseverative behavior, impaired pre-pulse inhibition (PPI), increased locomotor activity, anxiety-like behavior, and an increased sensitivity to psychostimulant, suggesting behaviors related to schizophrenia. These findings indicated that decreased drebrin produces deficits in cognitive function but not in spatial memory, probably via hypofunction of dendritic spines.
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MESH Headings
- Adaptation, Psychological/physiology
- Amphetamine/pharmacology
- Analysis of Variance
- Animals
- Animals, Genetically Modified
- Behavior, Animal
- Blotting, Western/methods
- Brain/drug effects
- Brain/metabolism
- Central Nervous System Stimulants/pharmacology
- Gene Transfer, Horizontal
- Genetic Vectors
- Injections, Intraventricular/methods
- Liposomes/metabolism
- Male
- Maze Learning/drug effects
- Maze Learning/physiology
- Motor Activity/drug effects
- Motor Activity/physiology
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Neuropeptides/antagonists & inhibitors
- Neuropeptides/deficiency
- Neuropeptides/genetics
- Oligonucleotides, Antisense/administration & dosage
- Oligonucleotides, Antisense/pharmacology
- Rats
- Rats, Wistar
- Reflex, Startle/physiology
- Sendai virus/genetics
- Time Factors
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Affiliation(s)
- Rika Kobayashi
- Division of Brain Science, Kitasato University Graduate School of Medical Sciences, Sagamihara 228-8555, Japan
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