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Morris CW, Watkins DS, Shah NR, Pennington T, Hens B, Qi G, Doud EH, Mosley AL, Atwood BK, Baucum AJ. Spinophilin Limits Metabotropic Glutamate Receptor 5 Scaffolding to the Postsynaptic Density and Cell Type Specifically Mediates Excessive Grooming. Biol Psychiatry 2023; 93:976-988. [PMID: 36822932 PMCID: PMC10191892 DOI: 10.1016/j.biopsych.2022.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Grooming dysfunction is a hallmark of the obsessive-compulsive spectrum disorder trichotillomania. Numerous preclinical studies have utilized SAPAP3-deficient mice for understanding the neurobiology of repetitive grooming, suggesting that excessive grooming is caused by increased metabotropic glutamate receptor 5 (mGluR5) activity in striatal direct- and indirect-pathway medium spiny neurons (MSNs). However, the MSN subtype-specific signaling mechanisms that mediate mGluR5-dependent adaptations underlying excessive grooming are not fully understood. Here, we investigated the MSN subtype-specific roles of the striatal signaling hub protein spinophilin in mediating repetitive motor dysfunction associated with mGluR5 function. METHODS Quantitative proteomics and immunoblotting were utilized to identify how spinophilin impacts mGluR5 phosphorylation and protein interaction changes. Plasticity and repetitive motor dysfunction associated with mGluR5 action were measured using our novel conditional spinophilin mouse model in which spinophilin was knocked out from striatal direct-pathway MSNs and/or indirect-pathway MSNs. RESULTS Loss of spinophilin only in indirect-pathway MSNs decreased performance of a novel motor repertoire, but loss of spinophilin in either MSN subtype abrogated striatal plasticity associated with mGluR5 function and prevented excessive grooming caused by SAPAP3 knockout mice or treatment with the mGluR5-specific positive allosteric modulator VU0360172 without impacting locomotion-relevant behavior. Biochemically, we determined that the spinophilin-mGluR5 interaction correlates with grooming behavior and that loss of spinophilin shifts mGluR5 interactions from lipid raft-associated proteins toward postsynaptic density proteins implicated in psychiatric disorders. CONCLUSIONS These results identify spinophilin as a novel striatal signaling hub molecule in MSNs that cell subtype specifically mediates behavioral, functional, and molecular adaptations associated with repetitive motor dysfunction in psychiatric disorders.
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Affiliation(s)
- Cameron W Morris
- Medical Neurosciences Graduate Program, Indiana University School of Medicine, Indianapolis, Indiana
| | - Darryl S Watkins
- Medical Neurosciences Graduate Program, Indiana University School of Medicine, Indianapolis, Indiana
| | - Nikhil R Shah
- Medical Neurosciences Graduate Program, Indiana University School of Medicine, Indianapolis, Indiana; Medical Scientists Training Program, Indiana University School of Medicine, Indianapolis, Indiana
| | - Taylor Pennington
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana
| | - Basant Hens
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Guihong Qi
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana; Center for Proteome Analysis, Indiana University School of Medicine, Indianapolis, Indiana
| | - Emma H Doud
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana; Center for Proteome Analysis, Indiana University School of Medicine, Indianapolis, Indiana; Melvin and Bren Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana; Center for Proteome Analysis, Indiana University School of Medicine, Indianapolis, Indiana; Melvin and Bren Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Brady K Atwood
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Anthony J Baucum
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana; Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana.
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Salek AB, Claeboe ET, Bansal R, Berbari NF, Baucum AJ. Spinophilin-dependent regulation of GluN2B-containing NMDAR-dependent calcium influx, GluN2B surface expression, and cleaved caspase expression. Synapse 2023; 77:e22264. [PMID: 36738175 DOI: 10.1002/syn.22264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/09/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
N-methyl-d-aspartate receptors (NMDARs) are calcium-permeable ion channels that are ubiquitously expressed within the glutamatergic postsynaptic density. Phosphorylation of NMDAR subunits defines receptor conductance and surface localization, two alterations that can modulate overall channel activity. Modulation of NMDAR phosphorylation by kinases and phosphatases regulates the amount of calcium entering the cell and subsequent activation of calcium-dependent processes. The dendritic spine enriched protein, spinophilin, is the major synaptic protein phosphatase 1 (PP1) targeting protein. Depending on the substrate, spinophilin can act as either a PP1 targeting protein, to permit substrate dephosphorylation, or a PP1 inhibitory protein, to enhance substrate phosphorylation. Spinophilin limits NMDAR function in a PP1-dependent manner. Specifically, we have previously shown that spinophilin sequesters PP1 away from the GluN2B subunit of the NMDAR, which results in increased phosphorylation of Ser-1284 on GluN2B. However, how spinophilin modifies NMDAR function is unclear. Herein, we utilize a Neuro2A cell line to detail that Ser-1284 phosphorylation increases calcium influx via GluN2B-containing NMDARs. Moreover, overexpression of spinophilin decreases GluN2B-containing NMDAR activity by decreasing its surface expression, an effect that is independent of Ser-1284 phosphorylation. In hippocampal neurons isolated from spinophilin knockout animals, there is an increase in cleaved caspase-3 levels, a marker of calcium-associated apoptosis, compared with wildtype mice. Taken together, our data demonstrate that spinophilin regulates GluN2B containing NMDAR phosphorylation, channel function, and trafficking and that loss of spinophilin enhances neuronal cleaved caspase-3 expression.
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Affiliation(s)
- Asma B Salek
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Emily T Claeboe
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Anthony J Baucum
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana, USA
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3
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Stickel KC, Mosley AL, Doud EH, Belecky-Adams TL, Baucum AJ. Mechanisms of spinophilin-dependent pancreas dysregulation underlying diabesity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527495. [PMID: 36798361 PMCID: PMC9934546 DOI: 10.1101/2023.02.07.527495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Objective Spinophilin is an F-actin binding and protein phosphatase 1 (PP1) targeting protein that acts as a scaffold of PP1 to its substrates. Spinophilin knockout (Spino-/-) mice have decreased fat mass, increased lean mass, and improved glucose tolerance, with no difference in feeding behaviors. While spinophilin is enriched in neurons, its roles in non-neuronal tissues, such as beta cells of the pancreatic islets, are unclear. Methods & Results We have corroborated and expanded upon previous studies to determine that Spino-/- mice have decreased weight gain and improved glucose tolerance in two different models of obesity. Using proteomics and immunoblotting-based approaches we identified multiple putative spinophilin interacting proteins isolated from intact pancreas and observed increased interactions of spinophilin with exocrine, ribosomal, and cytoskeletal protein classes that mediate peptide hormone production, processing, and/or release in Leprdb/db and/or high fat-fed (HFF) models of obesity. Moreover, loss of spinophilin specifically in pancreatic beta cells improved glucose tolerance without impacting body weight. Conclusion Our data further support a role for spinophilin in mediating pathophysiological changes in body weight and whole-body metabolism associated with obesity and provide the first evidence that spinophilin mediates obesity-dependent pancreatic dysfunction that leads to deficits in glucose homeostasis or diabesity.
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Affiliation(s)
- Kaitlyn C. Stickel
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Amber L. Mosley
- Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, USA
- Center for Proteome Analysis, Indiana University, Indianapolis, IN, USA
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine (IUSM), Indiana University, Indianapolis, IN, USA
| | - Emma H. Doud
- Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, USA
- Center for Proteome Analysis, Indiana University, Indianapolis, IN, USA
| | - Teri L. Belecky-Adams
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Anthony J. Baucum
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
- Department of Pharmacology and Toxicology, Indiana University, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, USA
- Center for Diabetes and Metabolic Diseases Indiana University School of Medicine, Indianapolis, IN, USA
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Detering NT, Schüning T, Hensel N, Claus P. The phospho-landscape of the survival of motoneuron protein (SMN) protein: relevance for spinal muscular atrophy (SMA). Cell Mol Life Sci 2022; 79:497. [PMID: 36006469 PMCID: PMC11071818 DOI: 10.1007/s00018-022-04522-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/27/2022] [Accepted: 08/09/2022] [Indexed: 11/03/2022]
Abstract
Spinal muscular atrophy (SMA) is caused by low levels of the survival of motoneuron (SMN) Protein leading to preferential degeneration of lower motoneurons in the ventral horn of the spinal cord and brain stem. However, the SMN protein is ubiquitously expressed and there is growing evidence of a multisystem phenotype in SMA. Since a loss of SMN function is critical, it is important to decipher the regulatory mechanisms of SMN function starting on the level of the SMN protein itself. Posttranslational modifications (PTMs) of proteins regulate multiple functions and processes, including activity, cellular trafficking, and stability. Several PTM sites have been identified within the SMN sequence. Here, we map the identified SMN PTMs highlighting phosphorylation as a key regulator affecting localization, stability and functions of SMN. Furthermore, we propose SMN phosphorylation as a crucial factor for intracellular interaction and cellular distribution of SMN. We outline the relevance of phosphorylation of the spinal muscular atrophy (SMA) gene product SMN with regard to basic housekeeping functions of SMN impaired in this neurodegenerative disease. Finally, we compare SMA patient mutations with putative and verified phosphorylation sites. Thus, we emphasize the importance of phosphorylation as a cellular modulator in a clinical perspective as a potential additional target for combinatorial SMA treatment strategies.
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Affiliation(s)
- Nora Tula Detering
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Tobias Schüning
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Niko Hensel
- Ottawa Hospital Research Institute (OHRI), Ottawa, Canada
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Peter Claus
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany.
- Center for Systems Neuroscience (ZSN), Hannover, Germany.
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Saggu S, Chen Y, Chen L, Pizarro D, Pati S, Law WJ, McMahon L, Jiao K, Wang Q. A peptide blocking the ADORA1-neurabin interaction is anticonvulsant and inhibits epilepsy in an Alzheimer's model. JCI Insight 2022; 7:155002. [PMID: 35674133 PMCID: PMC9220929 DOI: 10.1172/jci.insight.155002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 04/20/2022] [Indexed: 11/17/2022] Open
Abstract
Epileptic seizures are common sequelae of stroke, acute brain injury, and chronic neurodegenerative diseases, including Alzheimer's disease (AD), and cannot be effectively controlled in approximately 40% of patients, necessitating the development of novel therapeutic agents. Activation of the A1 receptor (A1R) by endogenous adenosine is an intrinsic mechanism to self-terminate seizures and protect neurons from excitotoxicity. However, targeting A1R for neurological disorders has been hindered by side effects associated with its broad expression outside the nervous system. Here we aim to target the neural-specific A1R/neurabin/regulator of G protein signaling 4 (A1R/neurabin/RGS4) complex that dictates A1R signaling strength and response outcome in the brain. We developed a peptide that blocks the A1R-neurabin interaction to enhance A1R activity. Intracerebroventricular or i.n. administration of this peptide shows marked protection against kainate-induced seizures and neuronal death. Furthermore, in an AD mouse model with spontaneous seizures, nasal delivery of this blocking peptide reduces epileptic spike frequency. Significantly, the anticonvulsant and neuroprotective effects of this peptide are achieved through enhanced A1R function in response to endogenous adenosine in the brain, thus, avoiding side effects associated with A1R activation in peripheral tissues and organs. Our study informs potentially new anti-seizure therapy applicable to epilepsy and other neurological illness with comorbid seizures.
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Affiliation(s)
- Shalini Saggu
- Departments of Cell, Developmental and Integrative Biology
| | - Yunjia Chen
- Departments of Cell, Developmental and Integrative Biology
| | - Liping Chen
- Departments of Cell, Developmental and Integrative Biology
| | | | | | - Wen Jing Law
- Departments of Cell, Developmental and Integrative Biology
| | - Lori McMahon
- Departments of Cell, Developmental and Integrative Biology
| | - Kai Jiao
- Department of Genetics, University of Alabama at Birmingham, Alabama, USA
| | - Qin Wang
- Departments of Cell, Developmental and Integrative Biology
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Mengr A, Hrubá L, Exnerová A, Holubová M, Popelová A, Železná B, Kuneš J, Maletínská L. Palmitoylated prolactin-releasing peptide reduced Aβ plaques and microgliosis in the cerebellum: APP/PS1 mice study. Curr Alzheimer Res 2021; 18:607-622. [PMID: 34551697 DOI: 10.2174/1567205018666210922110652] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/20/2021] [Accepted: 08/21/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND Prolactin-releasing peptide (PrRP) is a potential drug for the treatment of obesity and associated type 2 diabetes mellitus (T2DM) due to its strong anorexigenic and antidiabetic properties. In our recent study, the lipidized PrRP analog palm11-PrRP31 was proven to exert beneficial effects in APP/PS1 mice, a model of Alzheimer´s disease (AD)-like amyloid-β (Aβ) pathology, reducing the Aβ plaque load, microgliosis and astrocytosis in the hippocampus and cortex. OBJECTIVE In this study, we focused on the neuroprotective and anti-inflammatory effects of palm11-PrRP31 and its possible impact on synaptogenesis in the cerebellum of APP/PS1 mice, because others have suggested that cerebellar Aβ plaques contribute to cognitive deficits in AD. METHODS APP/PS1 mice were treated subcutaneously with palm11-PrRP31 for 2 months, then immunoblotting and immunohistochemistry were used to quantify pathological markers connected to AD, compared to control mice. RESULTS In the cerebella of 8 months old APP/PS1 mice, we found widespread Aβ plaques surrounded by activated microglia detected by ionized calcium-binding adapter molecule (Iba1), but no increase in astrocytic marker glial fibrillary acidic protein (GFAP) compared to controls. Interestingly, no difference in both presynaptic markers syntaxin1A and postsynaptic marker spinophilin was registered between APP/PS1 and control mice. Palm11-PrRP31 treatment significantly reduced the Aβ plaque load and microgliosis in the cerebellum. Furthermore, palm11-PrRP31 increased synaptogenesis and attenuated neuroinflammation and apoptosis in the hippocampus of APP/PS1 mice. CONCLUSION These results suggest palm11-PrRP31 is a promising agent for the treatment of neurodegenerative disorders.
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Affiliation(s)
- Anna Mengr
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Lucie Hrubá
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Aneta Exnerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Martina Holubová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Andrea Popelová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Blanka Železná
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Jaroslav Kuneš
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
| | - Lenka Maletínská
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6. Czech Republic
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Verdugo-Sivianes EM, Carnero A. Role of the Holoenzyme PP1-SPN in the Dephosphorylation of the RB Family of Tumor Suppressors During Cell Cycle. Cancers (Basel) 2021; 13:cancers13092226. [PMID: 34066428 PMCID: PMC8124259 DOI: 10.3390/cancers13092226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Cell cycle progression is highly regulated by modulating the phosphorylation status of retinoblastoma (RB) family proteins. This process is controlled by a balance in the action of kinases, such as the complexes formed by cyclin-dependent kinases (CDKs) and cyclins, and phosphatases, mainly the protein phosphatase 1 (PP1). However, while the phosphorylation of the RB family has been largely studied, its dephosphorylation is less known. Recently, the PP1-Spinophilin (SPN) holoenzyme has been described as the main phosphatase responsible for the dephosphorylation of RB proteins during the G0/G1 transition and at the end of G1. Here, we describe the regulation of the phosphorylation status of RB family proteins, giving importance not only to their inactivation by phosphorylation but also to their dephosphorylation to restore the cell cycle. Abstract Cell cycle progression is highly regulated by modulating the phosphorylation status of the retinoblastoma protein (pRB) and the other two members of the RB family, p107 and p130. This process is controlled by a balance in the action of kinases, such as the complexes formed by cyclin-dependent kinases (CDKs) and cyclins, and phosphatases, mainly the protein phosphatase 1 (PP1). However, while the phosphorylation of the RB family has been largely studied, its dephosphorylation is less known. Phosphatases are holoenzymes formed by a catalytic subunit and a regulatory protein with substrate specificity. Recently, the PP1-Spinophilin (SPN) holoenzyme has been described as the main phosphatase responsible for the dephosphorylation of RB proteins during the G0/G1 transition and at the end of G1. Moreover, SPN has been described as a tumor suppressor dependent on PP1 in lung and breast tumors, where it promotes tumorigenesis by increasing the cancer stem cell pool. Therefore, a connection between the cell cycle and stem cell biology has also been proposed via SPN/PP1/RB proteins.
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Affiliation(s)
- Eva M. Verdugo-Sivianes
- Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Avda. Manuel Siurot s/n, 41013 Seville, Spain;
- CIBERONC, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Amancio Carnero
- Instituto de Biomedicina de Sevilla, IBIS, Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Avda. Manuel Siurot s/n, 41013 Seville, Spain;
- CIBERONC, Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-955-92-31-11
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Regulation of Synaptic Transmission and Plasticity by Protein Phosphatase 1. J Neurosci 2021; 41:3040-3050. [PMID: 33827970 DOI: 10.1523/jneurosci.2026-20.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/22/2023] Open
Abstract
Protein phosphatases, by counteracting protein kinases, regulate the reversible phosphorylation of many substrates involved in synaptic plasticity, a cellular model for learning and memory. A prominent phosphatase regulating synaptic plasticity and neurologic disorders is the serine/threonine protein phosphatase 1 (PP1). PP1 has three isoforms (α, β, and γ, encoded by three different genes), which are regulated by a vast number of interacting subunits that define their enzymatic substrate specificity. In this review, we discuss evidence showing that PP1 regulates synaptic transmission and plasticity, as well as presenting novel models of PP1 regulation suggested by recent experimental evidence. We also outline the required targeting of PP1 by neurabin and spinophilin to achieve substrate specificity at the synapse to regulate AMPAR and NMDAR function. We then highlight the role of inhibitor-2 in regulating PP1 function in plasticity, including its positive regulation of PP1 function in vivo in memory formation. We also discuss the distinct function of the three PP1 isoforms in synaptic plasticity and brain function, as well as briefly discuss the role of inhibitory phosphorylation of PP1, which has received recent emphasis in the regulation of PP1 activity in neurons.
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Hwang S, Lee PCW, Shin DM, Hong JH. Modulated Start-Up Mode of Cancer Cell Migration Through Spinophilin-Tubular Networks. Front Cell Dev Biol 2021; 9:652791. [PMID: 33768098 PMCID: PMC7985070 DOI: 10.3389/fcell.2021.652791] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 11/26/2022] Open
Abstract
Spinophilin (SPL) is a multifunctional actin-binding scaffolding protein. Although increased research on SPL in cancer biology has revealed a tumor suppressive role, its modulation in cancer biology, and oncological relevance remains elusive. Thus, we determined the role of SPL in the modulation of the junctional network and cellular migration in A549 lung cancer cell line. Knockdown of SPL promoted cancer cell invasion in agarose spot and scratch wound assays. Attenuation of SPL expression also enhanced invadopodia, as revealed by enhanced vinculin spots, and enhanced sodium bicarbonate cotransporter NBC activity without enhancing membranous expression of NBCn1. Disruption of the tubular structure with nocodazole treatment revealed enhanced SPL expression and reduced NBC activity and A549 migration. SPL-mediated junctional modulation and tubular stability affected bicarbonate transporter activity in A549 cells. The junctional modulatory function of SPL in start-up migration, such as remodeling of tight junctions, enhanced invadopodia, and increased NBC activity, revealed here would support fundamental research and the development of an initial target against lung cancer cell migration.
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Affiliation(s)
- Soyoung Hwang
- Department of Physiology, College of Medicine, Gachon University, Incheon, South Korea
| | - Peter Chang-Whan Lee
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| | - Dong Min Shin
- Department of Oral Biology, Yonsei University College of Dentistry, Seoul, South Korea
| | - Jeong Hee Hong
- Department of Physiology, College of Medicine, Gachon University, Incheon, South Korea.,Department of Health Sciences and Technology, GAIHST, Lee Gil Ya Cancer and Diabetes Institute, Incheon, South Korea
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Platholi J, Hemmings HC. Modulation of dendritic spines by protein phosphatase-1. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2020; 90:117-144. [PMID: 33706930 DOI: 10.1016/bs.apha.2020.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Protein phosphatase-1 (PP-1), a highly conserved multifunctional serine/threonine phosphatase, is enriched in dendritic spines where it plays a major role in modulating excitatory synaptic activity. In addition to established functions in spine maturation and development, multi-subunit holoenzyme forms of PP-1 modulate higher-order cognitive functions such learning and memory. Mechanisms involved in regulating PP-1 activity and localization in spines include interactions with neurabin and spinophilin, structurally related synaptic scaffolding proteins associated with the actin cytoskeleton. Since PP-1 is a critical element in synaptic development, signaling, and plasticity, alterations in PP-1 signaling in dendritic spines are implicated in various neurological and psychiatric disorders. The effects of PP-1 depend on its isoform-specific association with regulatory proteins and activation of downstream signaling pathways. Here we review the role of PP-1 and its binding proteins neurabin and spinophilin in both developing and established dendritic spines, as well as some of the disorders that result from its dysregulation.
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Affiliation(s)
- Jimcy Platholi
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States; Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, United States
| | - Hugh C Hemmings
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States; Department of Pharmacology, Weill Cornell Medicine, New York, NY, United States.
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11
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Zhang Y, Song L, Dong H, Kim DS, Sun Z, Boger H, Wang Q, Wang H. Spinophilin-deficient mice are protected from diet-induced obesity and insulin resistance. Am J Physiol Endocrinol Metab 2020; 319:E354-E362. [PMID: 32603260 PMCID: PMC7473908 DOI: 10.1152/ajpendo.00114.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/27/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023]
Abstract
Browning of white adipose tissue (WAT) has been shown to reduce obesity and obesity-related complications, suggesting that factors that promote WAT browning may have applications in the development of therapeutic strategies for treating obesity. Here, we show that ablation of spinophilin (SPL), a ubiquitously expressed, multidomain scaffolding protein, increases metabolism and improves energy balance. Male and female SPL knockout (KO) and wild-type (WT) littermate controls were fed a chow diet or a high-fat diet (HFD). Body weight, hepatic steatosis, glucose and insulin tolerance, physical activity, and expression of browning genes in adipose tissues were measured and compared. Male SPL knockout (KO) mice fed a chow diet were significantly leaner, had lower body weights, and exhibited better glucose tolerance and insulin sensitivity than wild-type (WT) littermate controls. When fed an HFD, SPL KO mice were protected from increased body fat, weight gain, hepatic steatosis, hyperinsulinemia, and insulin resistance. Physical activity of SPL KO mice was markedly increased compared with WT controls. Furthermore, expression of the brown adipocyte marker, uncoupling protein-1 (UCP-1), and the mitochondrial activity markers, cd137 and c-idea, were significantly increased in visceral WAT (vWAT) of SPL KO mice, suggesting that SPL knockout protected the mice from HFD-induced obesity and its metabolic complications, at least in part, by promoting the browning of white adipocytes in vWAT. Our data identify a critical role of SPL in regulating glucose homeostasis, obesity, and adipocyte browning. These results suggest SPL may serve as a drug target for obesity and diabetes.
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Affiliation(s)
- Yong Zhang
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
- College of Life Sciences, Qingdao Agricultural University, Qingdao, People's Republic of China
| | - Lili Song
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
| | - Huansheng Dong
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
- College of Life Sciences, Qingdao Agricultural University, Qingdao, People's Republic of China
| | - Do-Sung Kim
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
| | - Zhen Sun
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
| | - Heather Boger
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina
| | - Qin Wang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham
| | - Hongjun Wang
- Department of Surgery, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
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12
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Salek AB, Edler MC, McBride JP, Baucum AJ. Spinophilin regulates phosphorylation and interactions of the GluN2B subunit of the N-methyl-d-aspartate receptor. J Neurochem 2019; 151:185-203. [PMID: 31325175 DOI: 10.1111/jnc.14831] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/21/2019] [Accepted: 07/13/2019] [Indexed: 12/20/2022]
Abstract
N-methyl-d-Aspartate receptors (NMDARs) are abundant postsynaptic proteins that are critical for normal synaptic communication. NMDAR channel function is regulated by multiple properties, including phosphorylation. Inhibition of protein phosphatase 1 (PP1) in hippocampal neurons increases NMDAR activity, an effect abrogated by loss of spinophilin, the major PP1-targeting protein in the postsynaptic density. However, how spinophilin regulates PP1-dependent NMDAR function is unclear. We hypothesize that spinophilin regulates PP1 binding to the NMDAR to alter NMDAR phosphorylation. Our data demonstrate that spinophilin interacts with the GluN2B subunit of the NMDAR. In human embryonic kidney 293 FT cells, activation and/or overexpression of protein kinase A increased the association between spinophilin and the GluN2B subunit of the NMDAR. Functionally, we found that spinophilin overexpression decreased PP1 binding to the GluN2B subunit of the NMDAR and attenuated the PP1-dependent dephosphorylation of GluN2B at Ser-1284. Moreover, in P28 hippocampal lysates isolated from spinophilin KO compared to WT mice, there was increased binding of GluN2B to PP1, decreased phosphorylation of GluN2B at Ser-1284, and altered GluN2B protein interactions with postsynaptic density-enriched proteins. Together, our data demonstrate that spinophilin decreases PP1 binding to GluN2B and concomitantly enhances the phosphorylation of GluN2B at Ser-1284. The putative consequences of these spinophilin-dependent alterations in GluN2B phosphorylation and interactions on synaptic GluN2B localization and function are discussed. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Asma B Salek
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA
| | - Michael C Edler
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jonathon P McBride
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA
| | - Anthony J Baucum
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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13
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Areal LB, Hamilton A, Martins-Silva C, Pires RGW, Ferguson SSG. Neuronal scaffolding protein spinophilin is integral for cocaine-induced behavioral sensitization and ERK1/2 activation. Mol Brain 2019; 12:15. [PMID: 30803445 PMCID: PMC6388481 DOI: 10.1186/s13041-019-0434-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/04/2019] [Indexed: 01/23/2023] Open
Abstract
Spinophilin is a scaffolding protein enriched in dendritic spines with integral roles in the regulation of spine density and morphology, and the modulation of synaptic plasticity. The ability of spinophilin to alter synaptic strength appears to involve its scaffolding of key synaptic proteins, including the important structural element F-actin, AMPA/NMDA modulator protein phosphatase 1, and neuromodulatory G-protein coupled receptors, including dopamine receptor D2 and metabotropic glutamate receptor 5. Additionally, spinophilin is highly expressed in the striatum, a brain region that is fundamentally involved in reward-processing and locomotor activity which receives both glutamatergic and dopaminergic inputs. Therefore, we aimed to investigate the role of spinophilin in behavioral responses to cocaine, evaluating wild-type and spinophilin knockout mice followed by the examination of underlying molecular alterations. Although acute locomotor response was not affected, deletion of spinophilin blocked the development and expression of behavioral sensitization to cocaine while maintaining normal conditioned place preference. This behavioral alteration in spinophilin knockout mice was accompanied by attenuated c-Fos and ∆FosB expression following cocaine administration and blunted cocaine-induced phosphorylation of ERK1/2 in the striatum, with no change in other relevant signaling molecules. Therefore, we suggest spinophilin fulfills an essential role in cocaine-induced behavioral sensitization, likely via ERK1/2 phosphorylation and induction of c-Fos and ∆FosB in the striatum, a mechanism that may underlie specific processes in cocaine addiction.
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Affiliation(s)
- Lorena Bianchine Areal
- Department of Cellular and Molecular Medicine and University of Ottawa Brain and Mind Institute, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.,Graduate Program in Neuroscience, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | - Alison Hamilton
- Department of Cellular and Molecular Medicine and University of Ottawa Brain and Mind Institute, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada
| | - Cristina Martins-Silva
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito, Santo, Vitoria, ES, 29043-910, Brazil
| | - Rita Gomes Wanderley Pires
- Graduate Program in Neuroscience, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.,Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito, Santo, Vitoria, ES, 29043-910, Brazil
| | - Stephen S G Ferguson
- Department of Cellular and Molecular Medicine and University of Ottawa Brain and Mind Institute, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
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14
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Watkins DS, True JD, Mosley AL, Baucum AJ. Proteomic Analysis of the Spinophilin Interactome in Rodent Striatum Following Psychostimulant Sensitization. Proteomes 2018; 6:proteomes6040053. [PMID: 30562941 PMCID: PMC6313900 DOI: 10.3390/proteomes6040053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/10/2018] [Accepted: 12/13/2018] [Indexed: 12/13/2022] Open
Abstract
Glutamatergic projections from the cortex and dopaminergic projections from the substantia nigra or ventral tegmental area synapse on dendritic spines of specific GABAergic medium spiny neurons (MSNs) in the striatum. Direct pathway MSNs (dMSNs) are positively coupled to protein kinase A (PKA) signaling and activation of these neurons enhance specific motor programs whereas indirect pathway MSNs (iMSNs) are negatively coupled to PKA and inhibit competing motor programs. An imbalance in the activity of these two programs is observed following increased dopamine signaling associated with exposure to psychostimulant drugs of abuse. Alterations in MSN signaling are mediated by changes in MSN protein post-translational modifications, including phosphorylation. Whereas direct changes in specific kinases, such as PKA, regulate different effects observed in the two MSN populations, alterations in the specific activity of serine/threonine phosphatases, such as protein phosphatase 1 (PP1) are less well known. This lack of knowledge is due, in part, to unknown, cell-specific changes in PP1 targeting proteins. Spinophilin is the major PP1-targeting protein in striatal postsynaptic densities. Using proteomics and immunoblotting approaches along with a novel transgenic mouse expressing hemagglutainin (HA)-tagged spinophilin in dMSNs and iMSNs, we have uncovered cell-specific regulation of the spinophilin interactome following a sensitizing regimen of amphetamine. These data suggest regulation of spinophilin interactions in specific MSN cell types and may give novel insight into putative cell-specific, phosphatase-dependent signaling pathways associated with psychostimulants.
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Affiliation(s)
- Darryl S Watkins
- Stark Neurosciences Research Institute, Indiana University School of Medicine Medical Neuroscience Graduate Program, Indianapolis, IN 46278, USA.
| | - Jason D True
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46278, USA.
- Department of Biology, Ball State University, Muncie, IN 47306, USA.
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46278, USA.
| | - Anthony J Baucum
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA.
- Stark Neurosciences Research Institute Indianapolis, Indianapolis, IN 46202, USA.
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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15
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Edler MC, Salek AB, Watkins DS, Kaur H, Morris CW, Yamamoto BK, Baucum AJ. Mechanisms Regulating the Association of Protein Phosphatase 1 with Spinophilin and Neurabin. ACS Chem Neurosci 2018; 9:2701-2712. [PMID: 29786422 DOI: 10.1021/acschemneuro.8b00144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Protein phosphorylation is a key mediator of signal transduction, allowing for dynamic regulation of substrate activity. Whereas protein kinases obtain substrate specificity by targeting specific amino acid sequences, serine/threonine phosphatase catalytic subunits are much more promiscuous in their ability to dephosphorylate substrates. To obtain substrate specificity, serine/threonine phosphatases utilize targeting proteins to regulate phosphatase subcellular localization and catalytic activity. Spinophilin and its homologue neurabin are two of the most abundant dendritic spine-localized protein phosphatase 1 (PP1) targeting proteins. The association between spinophilin and PP1 is increased in the striatum of animal models of Parkinson's disease (PD). However, mechanisms that regulate the association of spinophilin and neurabin with PP1 are unclear. Here, we report that the association between spinophilin and PP1α or PP1γ1 was increased by CDK5 expression and activation in a heterologous cell system. This increased association is at least partially due to phosphorylation of PP1. Conversely, CDK5 expression and activation decreased the association of PP1 with neurabin. As with dopamine depletion, methamphetamine (METH) abuse causes persistent alterations in dopamine signaling which influence striatal medium spiny neuron function and biochemistry. Moreover, both METH toxicity and dopamine depletion are associated with deficits in motor control and motor learning. Pathologically, we observed a decreased association of spinophilin with PP1 in rat striatum evaluated one month following a binge METH paradigm. Behaviorally, we found that loss of spinophilin recapitulates rotarod pathology previously observed in dopamine-depleted and METH-treated animals. Together, these data have implications in multiple disease states associated with altered dopamine signaling such as PD and psychostimulant drug abuse and delineate a novel mechanism by which PP1 interactions with spinophilin and neurabin may be differentially regulated.
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16
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Leslie SN, Nairn AC. cAMP regulation of protein phosphatases PP1 and PP2A in brain. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:64-73. [PMID: 30401536 DOI: 10.1016/j.bbamcr.2018.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 09/13/2018] [Indexed: 12/21/2022]
Abstract
Normal functioning of the brain is dependent upon a complex web of communication between numerous cell types. Within neuronal networks, the faithful transmission of information between neurons relies on an equally complex organization of inter- and intra-cellular signaling systems that act to modulate protein activity. In particular, post-translational modifications (PTMs) are responsible for regulating protein activity in response to neurochemical signaling. The key second messenger, cyclic adenosine 3',5'-monophosphate (cAMP), regulates one of the most ubiquitous and influential PTMs, phosphorylation. While cAMP is canonically viewed as regulating the addition of phosphate groups through its activation of cAMP-dependent protein kinases, it plays an equally critical role in regulating removal of phosphate through indirect control of protein phosphatase activity. This dichotomy of regulation by cAMP places it as one of the key regulators of protein activity in response to neuronal signal transduction throughout the brain. In this review we focus on the role of cAMP in regulation of the serine/threonine phosphatases protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) and the relevance of control of PP1 and PP2A to regulation of brain function and behavior.
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Affiliation(s)
- Shannon N Leslie
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States of America
| | - Angus C Nairn
- Department of Psychiatry, Yale University, New Haven, CT, United States of America
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17
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Ferreira M, Beullens M, Bollen M, Van Eynde A. Functions and therapeutic potential of protein phosphatase 1: Insights from mouse genetics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:16-30. [PMID: 30056088 PMCID: PMC7114192 DOI: 10.1016/j.bbamcr.2018.07.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/16/2018] [Accepted: 07/19/2018] [Indexed: 02/07/2023]
Abstract
Protein phosphatase 1 (PP1) catalyzes more than half of all phosphoserine/threonine dephosphorylation reactions in mammalian cells. In vivo PP1 does not exist as a free catalytic subunit but is always associated with at least one regulatory PP1-interacting protein (PIP) to generate a large set of distinct holoenzymes. Each PP1 complex controls the dephosphorylation of only a small subset of PP1 substrates. We screened the literature for genetically engineered mouse models and identified models for all PP1 isoforms and 104 PIPs. PP1 itself and at least 49 PIPs were connected to human disease-associated phenotypes. Additionally, phenotypes related to 17 PIPs were clearly linked to altered PP1 function, while such information was lacking for 32 other PIPs. We propose structural reverse genetics, which combines structural characterization of proteins with mouse genetics, to identify new PP1-related therapeutic targets. The available mouse models confirm the pleiotropic action of PP1 in health and diseases. Four protein phosphatases 1 (PP1) isoforms and >200 PP1-interacting proteins (PIPs) Genetically engineered mice of 49 PIPs display human disease-associated phenotypes. The use of structural reverse genetics to identify the PP1-dependent phenotypes Various interaction sites in PP1:PIP complexes suit for therapeutic targeting.
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Affiliation(s)
- Mónica Ferreira
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
| | - Monique Beullens
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, B-3000 Leuven, Belgium.
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18
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Morris CW, Watkins DS, Salek AB, Edler MC, Baucum AJ. The association of spinophilin with disks large-associated protein 3 (SAPAP3) is regulated by metabotropic glutamate receptor (mGluR) 5. Mol Cell Neurosci 2018; 90:60-69. [PMID: 29908232 PMCID: PMC6294707 DOI: 10.1016/j.mcn.2018.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 01/03/2023] Open
Abstract
Spinophilin is the most abundant protein phosphatase 1 targeting protein in the postsynaptic density of dendritic spines. Spinophilin associates with myriad synaptic proteins to regulate normal synaptic communication; however, the full complement of spinophilin interacting proteins and mechanisms regulating spinophilin interactions are unclear. Here we validate an association between spinophilin and the scaffolding protein, disks large-associated protein 3 (SAP90/PSD-95 associated protein 3; SAPAP3). Loss of SAPAP3 leads to obsessive-compulsive disorder (OCD)-like behaviors due to alterations in metabotropic glutamate receptor (mGluR) signaling. Here we report that spinophilin associates with SAPAP3 in the brain and in a heterologous cell system. Moreover, we have found that expression or activation of group I mGluRs along with activation of the mGluR-dependent kinase, protein kinase C β, enhances this interaction. Functionally, global loss of spinophilin attenuates amphetamine-induced hyperlocomotion, a striatal behavior associated with dopamine dysregulation and OCD. Together, these data delineate a novel link between mGluR signaling, spinophilin, and SAPAP3 in striatal pathophysiology.
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Affiliation(s)
- Cameron W Morris
- Undergraduate Neuroscience program, Indiana University-Purdue University Indianapolis, School of Science, USA
| | | | - Asma B Salek
- Department of Biology, Indiana University-Purdue University Indianapolis, School of Science, USA
| | - Michael C Edler
- Department of Biology, Indiana University-Purdue University Indianapolis, School of Science, USA
| | - Anthony J Baucum
- Undergraduate Neuroscience program, Indiana University-Purdue University Indianapolis, School of Science, USA; Department of Biology, Indiana University-Purdue University Indianapolis, School of Science, USA; Stark Neurosciences Research, USA; Department of Pharmacology and Toxicology, Institute Indiana University School of Medicine, USA.
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19
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Wu H, Cottingham C, Chen L, Wang H, Che P, Liu K, Wang Q. Age-dependent differential regulation of anxiety- and depression-related behaviors by neurabin and spinophilin. PLoS One 2017; 12:e0180638. [PMID: 28700667 PMCID: PMC5503268 DOI: 10.1371/journal.pone.0180638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/19/2017] [Indexed: 12/28/2022] Open
Abstract
Affective disorders impact nearly 10% of the adult population in the United States in a given year. Synaptic dysfunction has recently emerged as a key neurobiological mechanism underlying affective disorders such as anxiety and depression. In this study, we investigate the potential role of two synaptic scaffolding proteins, neurabin and spinophilin, in regulating anxiety- and depression-related behaviors at different ages using genetically deficient mice. Loss of the neurabin gene reduces anxiety-like behavior in the elevated zero maze in young adult mice (3-5 months old), but not in middle aged mice (11-13 months old), whereas loss of spinophilin decreases anxiety in middle-aged mice, but not in young adult mice. Neurabin knockout (KO) mice also show reduced immobility in the repeated force swim test (FST) at 3-5 months, but not 11-3 months, of age, compared to age- and strain-matched wild type (WT) controls. Conversely, spinophilin KO mice display a lower level of this behavioral despair than matched WT controls after repeated FST trials at the middle age (11-13 months) but not the young age (3-5 months). Together, these data indicate that, despite their structural similarities and overlapping function in regulating synaptic cytoskeleton, the two homologs neurabin and spinophilin play important yet distinct roles in the regulation of anxiety- and depression-like behaviors in an age-dependent manner. Our studies provide new insights into the complex neurobiology of affective disorders.
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Affiliation(s)
- Huiying Wu
- Ultrasonic Diagnosis Department, The Second Hospital of Jilin University, Changchun, Jilin, China
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Christopher Cottingham
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, United States of America
| | - Liping Chen
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Hongxia Wang
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Pulin Che
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Kexiang Liu
- Department of Cardiovascular Surgery, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Qin Wang
- Departments of Cell, Molecular and Developmental Biology, University of Alabama at Birmingham, Birmingham, AL, United States of America
- * E-mail:
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20
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Mechanisms and Consequences of Dopamine Depletion-Induced Attenuation of the Spinophilin/Neurofilament Medium Interaction. Neural Plast 2017. [PMID: 28634551 PMCID: PMC5467389 DOI: 10.1155/2017/4153076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Signaling changes that occur in the striatum following the loss of dopamine neurons in the Parkinson disease (PD) are poorly understood. While increases in the activity of kinases and decreases in the activity of phosphatases have been observed, the specific consequences of these changes are less well understood. Phosphatases, such as protein phosphatase 1 (PP1), are highly promiscuous and obtain substrate selectivity via targeting proteins. Spinophilin is the major PP1-targeting protein enriched in the postsynaptic density of striatal dendritic spines. Spinophilin association with PP1 is increased concurrent with decreases in PP1 activity in an animal model of PD. Using proteomic-based approaches, we observed dopamine depletion-induced decreases in spinophilin binding to multiple protein classes in the striatum. Specifically, there was a decrease in the association of spinophilin with neurofilament medium (NF-M) in dopamine-depleted striatum. Using a heterologous cell line, we determined that spinophilin binding to NF-M required overexpression of the catalytic subunit of protein kinase A and was decreased by cyclin-dependent protein kinase 5. Functionally, we demonstrate that spinophilin can decrease NF-M phosphorylation. Our data determine mechanisms that regulate, and putative consequences of, pathological changes in the association of spinophilin with NF-M that are observed in animal models of PD.
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21
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Martin B, Wang R, Cong WN, Daimon CM, Wu WW, Ni B, Becker KG, Lehrmann E, Wood WH, Zhang Y, Etienne H, van Gastel J, Azmi A, Janssens J, Maudsley S. Altered learning, memory, and social behavior in type 1 taste receptor subunit 3 knock-out mice are associated with neuronal dysfunction. J Biol Chem 2017; 292:11508-11530. [PMID: 28522608 DOI: 10.1074/jbc.m116.773820] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 05/03/2017] [Indexed: 12/19/2022] Open
Abstract
The type 1 taste receptor member 3 (T1R3) is a G protein-coupled receptor involved in sweet-taste perception. Besides the tongue, the T1R3 receptor is highly expressed in brain areas implicated in cognition, including the hippocampus and cortex. As cognitive decline is often preceded by significant metabolic or endocrinological dysfunctions regulated by the sweet-taste perception system, we hypothesized that a disruption of the sweet-taste perception in the brain could have a key role in the development of cognitive dysfunction. To assess the importance of the sweet-taste receptors in the brain, we conducted transcriptomic and proteomic analyses of cortical and hippocampal tissues isolated from T1R3 knock-out (T1R3KO) mice. The effect of an impaired sweet-taste perception system on cognition functions were examined by analyzing synaptic integrity and performing animal behavior on T1R3KO mice. Although T1R3KO mice did not present a metabolically disrupted phenotype, bioinformatic interpretation of the high-dimensionality data indicated a strong neurodegenerative signature associated with significant alterations in pathways involved in neuritogenesis, dendritic growth, and synaptogenesis. Furthermore, a significantly reduced dendritic spine density was observed in T1R3KO mice together with alterations in learning and memory functions as well as sociability deficits. Taken together our data suggest that the sweet-taste receptor system plays an important neurotrophic role in the extralingual central nervous tissue that underpins synaptic function, memory acquisition, and social behavior.
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Affiliation(s)
- Bronwen Martin
- From the Metabolism Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Rui Wang
- From the Metabolism Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Wei-Na Cong
- From the Metabolism Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Caitlin M Daimon
- From the Metabolism Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Wells W Wu
- From the Metabolism Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Bin Ni
- the Receptor Pharmacology Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Kevin G Becker
- the Gene Expression and Genomics Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Elin Lehrmann
- the Gene Expression and Genomics Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - William H Wood
- the Gene Expression and Genomics Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Yongqing Zhang
- the Gene Expression and Genomics Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224
| | - Harmonie Etienne
- the Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, AN-2610 Antwerp, Belgium, and.,the Department of Biomedical Sciences, University of Antwerp, AN-2610 Antwerp, Belgium
| | - Jaana van Gastel
- the Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, AN-2610 Antwerp, Belgium, and.,the Department of Biomedical Sciences, University of Antwerp, AN-2610 Antwerp, Belgium
| | - Abdelkrim Azmi
- the Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, AN-2610 Antwerp, Belgium, and.,the Department of Biomedical Sciences, University of Antwerp, AN-2610 Antwerp, Belgium
| | - Jonathan Janssens
- the Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, AN-2610 Antwerp, Belgium, and.,the Department of Biomedical Sciences, University of Antwerp, AN-2610 Antwerp, Belgium
| | - Stuart Maudsley
- the Receptor Pharmacology Unit, NIA, National Institutes of Health, Baltimore, Maryland 21224, .,the Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, AN-2610 Antwerp, Belgium, and.,the Department of Biomedical Sciences, University of Antwerp, AN-2610 Antwerp, Belgium
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22
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Di Sebastiano AR, Fahim S, Dunn HA, Walther C, Ribeiro FM, Cregan SP, Angers S, Schmid S, Ferguson SSG. Role of Spinophilin in Group I Metabotropic Glutamate Receptor Endocytosis, Signaling, and Synaptic Plasticity. J Biol Chem 2016; 291:17602-15. [PMID: 27358397 DOI: 10.1074/jbc.m116.722355] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Indexed: 11/06/2022] Open
Abstract
Activation of Group I metabotropic glutamate receptors (mGluRs) activates signaling cascades, resulting in calcium release from intracellular stores, ERK1/2 activation, and long term changes in synaptic activity that are implicated in learning, memory, and neurodegenerative diseases. As such, elucidating the molecular mechanisms underlying Group I mGluR signaling is important for understanding physiological responses initiated by the activation of these receptors. In the current study, we identify the multifunctional scaffolding protein spinophilin as a novel Group I mGluR-interacting protein. We demonstrate that spinophilin interacts with the C-terminal tail and second intracellular loop of Group I mGluRs. Furthermore, we show that interaction of spinophilin with Group I mGluRs attenuates receptor endocytosis and phosphorylation of ERK1/2, an effect that is dependent upon the interaction of spinophilin with the C-terminal PDZ binding motif encoded by Group I mGluRs. Spinophilin knock-out results in enhanced mGluR5 endocytosis as well as increased ERK1/2, AKT, and Ca(2+) signaling in primary cortical neurons. In addition, the loss of spinophilin expression results in impaired mGluR5-stimulated LTD. Our results indicate that spinophilin plays an important role in regulating the activity of Group I mGluRs as well as their influence on synaptic activity.
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Affiliation(s)
- Andrea R Di Sebastiano
- From the J. Allyn Taylor Centre for Cell Biology, Robarts Research Institute, London, Ontario N6A 3K7, Canada
| | - Sandra Fahim
- From the J. Allyn Taylor Centre for Cell Biology, Robarts Research Institute, London, Ontario N6A 3K7, Canada
| | - Henry A Dunn
- the Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Cornelia Walther
- From the J. Allyn Taylor Centre for Cell Biology, Robarts Research Institute, London, Ontario N6A 3K7, Canada
| | - Fabiola M Ribeiro
- the Departamento de Bioquimica e Imunologia, ICB, Universidade Federa de Minas Gerais, Belo Horizonte 31270-901, Brazil
| | - Sean P Cregan
- From the J. Allyn Taylor Centre for Cell Biology, Robarts Research Institute, London, Ontario N6A 3K7, Canada
| | - Stephane Angers
- the Leslie Dan Faculty of Pharmacy and Department of Pharmacology, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Susanne Schmid
- the Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A 3K7, Canada, and
| | - Stephen S G Ferguson
- the Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A 3K7, Canada, and
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Spinophilin-Targeted Protein Phosphatase-1 Alleviated Inflammatory Pain by Negative Control of MEK/ERK Signaling in Spinal Cord Dorsal Horn of Rats. J Neurosci 2016; 35:13989-4001. [PMID: 26468199 DOI: 10.1523/jneurosci.2293-15.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
UNLABELLED Protein phosphatase-1 (PP1), anchored by regulatory or targeting proteins at excitatory glutamatergic synapses, controls the phosphorylation of postsynaptic substrates and regulates the neurotransmission and plasticity. Here, we found that spinophilin, an actin-binding protein that targets PP1 at postsynaptic density, served as a scaffold for extracellular signal-regulated kinase (ERK) signaling components. Through the C-terminal PDZ domain, spinophilin directly interacted with ERK and its upstream mitogen-activated protein kinase kinase (MEK). PP1, recruited by spinophilin, gained access to and dephosphorylated these kinases, exerting a tonic inhibition of ERK signaling. The removal of PP1 inhibition by disturbing spinophilin/PP1 interaction allowed a restricted activation of MEK/ERK at synapses, which in turn augmented the synaptic transmission specifically mediated by GluN2B subunit-containing N-methyl-d-aspartate subtype of glutamate receptors. We provided evidence that in pain-related spinal cord dorsal horn, the scaffolding function of spinophilin played an important role in the negative control of ERK-dependent and GluN2B-dependent pain sensitization. Expression of wild-type spinophilin produced an effective analgesic action against chronic inflammatory pain induced by complete Freund's adjuvant in rats. SIGNIFICANCE STATEMENT Extracellular signal-regulated kinase (ERK) relays the signals from multiple transmembrane receptors to a wide range of downstream effectors critical for the regulation of neuronal excitability and plasticity. The strength and duration of ERK signaling is spatiotemporally controlled by protein phosphatases. Sustained activation of ERK has been implicated in a variety of pathological processes. The current study revealed that spinophilin, a well characterized protein phosphatase 1 (PP1) synaptic targeting protein, was able to scaffold mitogen-activated protein kinase kinase (MEK) and ERK for dephosphorylation and inactivation by PP1. The loss of PP1 inhibition, as a result of spinophilin/PP1 dissociation, led to aberrant activation of MEK/ERK signaling, which had important implications for the exaggeration of NMDA receptor-dependent nociceptive synaptic transmission in spinal cord dorsal horn.
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Caudal D, Alvarsson A, Björklund A, Svenningsson P. Depressive-like phenotype induced by AAV-mediated overexpression of human α-synuclein in midbrain dopaminergic neurons. Exp Neurol 2015; 273:243-52. [DOI: 10.1016/j.expneurol.2015.09.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 08/18/2015] [Accepted: 09/03/2015] [Indexed: 01/10/2023]
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Muhammad K, Reddy-Alla S, Driller JH, Schreiner D, Rey U, Böhme MA, Hollmann C, Ramesh N, Depner H, Lützkendorf J, Matkovic T, Götz T, Bergeron DD, Schmoranzer J, Goettfert F, Holt M, Wahl MC, Hell SW, Scheiffele P, Walter AM, Loll B, Sigrist SJ. Presynaptic spinophilin tunes neurexin signalling to control active zone architecture and function. Nat Commun 2015; 6:8362. [PMID: 26471740 PMCID: PMC4633989 DOI: 10.1038/ncomms9362] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/13/2015] [Indexed: 11/17/2022] Open
Abstract
Assembly and maturation of synapses at the Drosophila neuromuscular junction
(NMJ) depend on trans-synaptic neurexin/neuroligin signalling, which is promoted by
the scaffolding protein Syd-1 binding to neurexin. Here we report that the scaffold
protein spinophilin binds to the C-terminal portion of neurexin and is needed to
limit neurexin/neuroligin signalling by acting antagonistic to Syd-1. Loss of
presynaptic spinophilin results in the formation of excess, but atypically small
active zones. Neuroligin-1/neurexin-1/Syd-1 levels are increased at
spinophilin mutant NMJs, and removal of single copies of the
neurexin-1, Syd-1 or neuroligin-1 genes suppresses the
spinophilin-active zone phenotype. Evoked transmission is strongly reduced at
spinophilin terminals, owing to a severely reduced release probability at
individual active zones. We conclude that presynaptic spinophilin fine-tunes
neurexin/neuroligin signalling to control active zone number and functionality,
thereby optimizing them for action potential-induced exocytosis. Synaptic assembly depends on trans-synaptic Neurexin/Neuroligin
signalling. Here, Muhammad et al. show that Spinophilin, a pre-synaptic
scaffolding protein, interacts with Neurexin, in competition with Syd-1, to regulate the
formation and function of synaptic active zones at Drosophila neuromuscular
junctions.
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Affiliation(s)
- Karzan Muhammad
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Suneel Reddy-Alla
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Jan H Driller
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Dietmar Schreiner
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, Basel 4056, Switzerland
| | - Ulises Rey
- NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | | | - Niraja Ramesh
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany
| | - Harald Depner
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | - Tanja Matkovic
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Torsten Götz
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | - Jan Schmoranzer
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany.,Leibniz Institut für Molekulare Pharmakologie, Robert-Roessle-Strasse 10, Berlin 13125, Germany
| | - Fabian Goettfert
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Mathew Holt
- VIB Center for the Biology of Disease, Herestraat 49, Leuven 3000, Belgium
| | - Markus C Wahl
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Peter Scheiffele
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, Basel 4056, Switzerland
| | - Alexander M Walter
- NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany.,Leibniz Institut für Molekulare Pharmakologie, Robert-Roessle-Strasse 10, Berlin 13125, Germany
| | - Bernhard Loll
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
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Loss of the tumor suppressor spinophilin (PPP1R9B) increases the cancer stem cell population in breast tumors. Oncogene 2015; 35:2777-88. [DOI: 10.1038/onc.2015.341] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 12/14/2022]
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27
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Banerji J. Asparaginase treatment side-effects may be due to genes with homopolymeric Asn codons (Review-Hypothesis). Int J Mol Med 2015; 36:607-26. [PMID: 26178806 PMCID: PMC4533780 DOI: 10.3892/ijmm.2015.2285] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/15/2015] [Indexed: 12/14/2022] Open
Abstract
The present treatment of childhood T-cell leukemias involves the systemic administration of prokary-otic L-asparaginase (ASNase), which depletes plasma Asparagine (Asn) and inhibits protein synthesis. The mechanism of therapeutic action of ASNase is poorly understood, as are the etiologies of the side-effects incurred by treatment. Protein expression from genes bearing Asn homopolymeric coding regions (N-hCR) may be particularly susceptible to Asn level fluctuation. In mammals, N-hCR are rare, short and conserved. In humans, misfunctions of genes encoding N-hCR are associated with a cluster of disorders that mimic ASNase therapy side-effects which include impaired glycemic control, dislipidemia, pancreatitis, compromised vascular integrity, and neurological dysfunction. This paper proposes that dysregulation of Asn homeostasis, potentially even by ASNase produced by the microbiome, may contribute to several clinically important syndromes by altering expression of N-hCR bearing genes. By altering amino acid abundance and modulating ribosome translocation rates at codon repeats, the microbiomic environment may contribute to genome decoding and to shaping the proteome. We suggest that impaired translation at poly Asn codons elevates diabetes risk and severity.
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Affiliation(s)
- Julian Banerji
- Center for Computational and Integrative Biology, MGH, Simches Research Center, Boston, MA 02114, USA
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28
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Dunn HA, Ferguson SSG. PDZ Protein Regulation of G Protein–Coupled Receptor Trafficking and Signaling Pathways. Mol Pharmacol 2015; 88:624-39. [DOI: 10.1124/mol.115.098509] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
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Varmuza S, Miri K. What does genetics tell us about imprinting and the placenta connection? Cell Mol Life Sci 2015; 72:51-72. [PMID: 25194419 PMCID: PMC11114082 DOI: 10.1007/s00018-014-1714-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 01/07/2023]
Abstract
Genomic imprinting is an epigenetic gene silencing phenomenon that is specific to eutherians in the vertebrate lineage. The acquisition of both placentation and genomic imprinting has spurred interest in the possible evolutionary link for many years. In this review we examine the genetic evidence and find that while many imprinted domains are anchored by genes required for proper placenta development in a parent of origin fashion, an equal number of imprinted genes have no apparent function that depends on imprinting. Examination of recent data from studies of molecular and genetic mechanisms points to a maternal control of the selection and maintenance of imprint marks, reinforcing the importance of the oocyte in the healthy development of the placenta and fetus.
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Affiliation(s)
- Susannah Varmuza
- Department of Cell and Systems Biology, University of Toronto, 611-25 Harbord Street, Toronto, M5S 3G5, Canada,
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30
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Aydin C, Oztan O, Isgor C. Hippocampal Y2 receptor-mediated mossy fiber plasticity is implicated in nicotine abstinence-related social anxiety-like behavior in an outbred rat model of the novelty-seeking phenotype. Pharmacol Biochem Behav 2014; 125:48-54. [PMID: 25158103 DOI: 10.1016/j.pbb.2014.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/12/2014] [Accepted: 08/17/2014] [Indexed: 10/24/2022]
Abstract
Experimentally naïve outbred rats display varying rates of locomotor reactivity in response to the mild stress of a novel environment. Namely, some display high rates (HR) whereas some display low rates (LR) of locomotor reactivity. Previous reports from our laboratory show that HRs, but not LRs, develop locomotor sensitization to a low dose nicotine challenge and exhibit increased social anxiety-like behavior following chronic intermittent nicotine training. Moreover, the hippocampus, specifically hippocampal Y2 receptor (Y2R)-mediated neuropeptide Y signaling is implicated in these nicotine-induced behavioral effects observed in HRs. The present study examines the structural substrates of the expression of locomotor sensitization to a low dose nicotine challenge and associated social anxiety-like behavior following chronic intermittent nicotine exposure during adolescence in the LRHR hippocampi. Our data showed that the expression of locomotor sensitization to the low dose nicotine challenge and the increase in social anxiety-like behavior were accompanied by an increase in mossy fiber terminal field size, as well as an increase in spinophilin mRNA levels in the hippocampus in nicotine pre-trained HRs compared to saline pre-trained controls. Furthermore, a novel, selective Y2R antagonist administered systemically during 1 wk of abstinence reversed the behavioral, molecular and neuromorphological effects observed in nicotine-exposed HRs. These results suggest that nicotine-induced neuroplasticity within the hippocampus may regulate abstinence-related negative affect in HRs, and implicate hippocampal Y2R in vulnerability to the behavioral and neuroplastic effects of nicotine in the novelty-seeking phenotype.
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Affiliation(s)
- Cigdem Aydin
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States.
| | - Ozge Oztan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Ceylan Isgor
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, United States
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31
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Joffe ME, Grueter CA, Grueter BA. Biological substrates of addiction. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2014; 5:151-171. [PMID: 24999377 PMCID: PMC4078878 DOI: 10.1002/wcs.1273] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/01/2013] [Accepted: 11/25/2013] [Indexed: 12/16/2022]
Abstract
This review is an introduction to addiction, the reward circuitry, and laboratory addiction models. Addiction is a chronic disease hallmarked by a state of compulsive drug seeking that persists despite negative consequences. Most of the advances in addiction research have centered on the canonical and contemporary drugs of abuse; however, addictions to other activities and stimuli also exist. Substances of abuse have the potential to induce long-lasting changes in the brain at the behavioral, circuit, and synaptic levels. Addiction-related behavioral changes involve initiation, escalation, and obsession to drug seeking and much of the current research is focused on mapping these manifestations to specific neural pathways. Drug abuse is well known to recruit components of the mesolimbic dopamine system, including the nucleus accumbens and ventral tegmental area. In addition, altered function of a wide variety of brain regions is tightly associated with specific manifestations of drug abuse. These regions peripheral to the mesolimbic pathway likely play a role in specific observed comorbidities and endophenotypes that can facilitate, or be caused by, substance abuse. Alterations in synaptic structure, function, and connectivity, as well as epigenetic and genetic mechanisms are thought to underlie the pathologies of addiction. In preclinical models, these persistent changes are studied at the levels of molecular pharmacology and biochemistry, ex vivo and in vivo electrophysiology, radiography, and behavior. Coordinating research efforts across these disciplines and examining cell type- and circuit-specific phenomena are crucial components for translating preclinical findings to viable medical interventions that effectively treat addiction and related disorders. WIREs Cogn Sci 2014, 5:151-171. doi: 10.1002/wcs.1273 Conflict of interest: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Max E. Joffe
- Department of Pharmacology, Vanderbilt University School of Medicine
| | - Carrie A. Grueter
- Department of Anesthesiology, Vanderbilt University School of Medicine
| | - Brad A. Grueter
- Department of Anesthesiology, Vanderbilt Brain Institute, Vanderbilt University School of Medicine
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Wass C, Pizzo A, Sauce B, Kawasumi Y, Sturzoiu T, Ree F, Otto T, Matzel LD. Dopamine D1 sensitivity in the prefrontal cortex predicts general cognitive abilities and is modulated by working memory training. Learn Mem 2013; 20:617-27. [PMID: 24129098 PMCID: PMC3799419 DOI: 10.1101/lm.031971.113] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A common source of variance (i.e., “general intelligence”) underlies an individual's performance across diverse tests of cognitive ability, and evidence indicates that the processing efficacy of working memory may serve as one such source of common variance. One component of working memory, selective attention, has been reported to co-vary with general intelligence, and dopamine D1 signaling in prefrontal cortex can modulate attentional abilities. Based on their aggregate performance across five diverse tests of learning, here we characterized the general cognitive ability (GCA) of CD-1 outbred mice. In response to a D1 agonist (SKF82958, 1 mg/kg), we then assessed the relationship between GCA and activation of D1 receptor (D1R)-containing neurons in the prelimbic region of the medial prefrontal cortex, the agranular insular cortex, and the dorsomedial striatum. Increased activation of D1R-containing neurons in the prelimbic cortex (but not the agranular insular cortex or dorsomedial striatum) was observed in animals of high GCA relative to those of low GCA (quantified by c-Fos activation in response to the D1 agonist). However, a Western blot analysis revealed no differences in the density of D1Rs in the prelimbic cortex between animals of high and low GCA. Last, it was observed that working memory training promoted an increase in animals’ GCA and enhanced D1R-mediated neuronal activation in the prelimbic cortex. These results suggest that the sensitivity (but not density) of D1Rs in the prelimbic cortex may both regulate GCA and be a target for working memory training.
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Affiliation(s)
- Christopher Wass
- Department of Psychology, Rutgers University, Piscataway, New Jersey 08854, USA
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33
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Tapocik JD, Luu TV, Mayo CL, Wang BD, Doyle E, Lee AD, Lee NH, Elmer GI. Neuroplasticity, axonal guidance and micro-RNA genes are associated with morphine self-administration behavior. Addict Biol 2013; 18:480-95. [PMID: 22804800 DOI: 10.1111/j.1369-1600.2012.00470.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Neuroadaptations in the ventral striatum (VS) and ventral midbrain (VMB) following chronic opioid administration are thought to contribute to the pathogenesis and persistence of opiate addiction. In order to identify candidate genes involved in these neuroadaptations, we utilized a behavior-genetics strategy designed to associate contingent intravenous drug self-administration with specific patterns of gene expression in inbred mice differentially predisposed to the rewarding effects of morphine. In a Yoked-control paradigm, C57BL/6J mice showed clear morphine-reinforced behavior, whereas DBA/2J mice did not. Moreover, the Yoked-control paradigm revealed the powerful consequences of self-administration versus passive administration at the level of gene expression. Morphine self-administration in the C57BL/6J mice uniquely up- or down-regulated 237 genes in the VS and 131 genes in the VMB. Interestingly, only a handful of the C57BL/6J self-administration genes (<3%) exhibited a similar expression pattern in the DBA/2J mice. Hence, specific sets of genes could be confidently assigned to regional effects of morphine in a contingent- and genotype-dependent manner. Bioinformatics analysis revealed that neuroplasticity, axonal guidance and micro-RNAs (miRNAs) were among the key themes associated with drug self-administration. Noteworthy were the primary miRNA genes H19 and micro-RNA containing gene (Mirg), processed, respectively, to mature miRNAs miR-675 and miR-154, because they are prime candidates to mediate network-like changes in responses to chronic drug administration. These miRNAs have postulated roles in dopaminergic neuron differentiation and mu-opioid receptor regulation. The strategic approach designed to focus on reinforcement-associated genes provides new insight into the role of neuroplasticity pathways and miRNAs in drug addiction.
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Affiliation(s)
| | - Truong V. Luu
- Department of Pharmacology and Physiology; The George Washington University Medical Center; Washington; DC; USA
| | - Cheryl L. Mayo
- Department of Psychiatry; Maryland Psychiatric Research Center; University of Maryland School of Medicine; Baltimore; MD; USA
| | - Bi-Dar Wang
- Department of Pharmacology and Physiology; The George Washington University Medical Center; Washington; DC; USA
| | - Erin Doyle
- Department of Pharmacology and Physiology; The George Washington University Medical Center; Washington; DC; USA
| | - Alec D. Lee
- Department of Pharmacology and Physiology; The George Washington University Medical Center; Washington; DC; USA
| | - Norman H. Lee
- Department of Pharmacology and Physiology; The George Washington University Medical Center; Washington; DC; USA
| | - Greg I. Elmer
- Department of Psychiatry; Maryland Psychiatric Research Center; University of Maryland School of Medicine; Baltimore; MD; USA
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Low expression of the putative tumour suppressor spinophilin is associated with higher proliferative activity and poor prognosis in patients with hepatocellular carcinoma. Br J Cancer 2013; 108:1830-7. [PMID: 23591196 PMCID: PMC3658515 DOI: 10.1038/bjc.2013.165] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Spinophilin, a multifunctional intracellular scaffold protein, is reduced in certain types of cancer and is regarded as a novel putative tumour suppressor protein. However, the role of spinophilin in hepatocellular carcinoma (HCC) has never been explored before. METHODS In this study, we determined for the first time the expression pattern of spinophilin in human HCC by immunohistochemistry and quantitative reverse transcriptase-PCR analysis. In addition, we performed immunohistochemical analysis of p53, p14(ARF) and the proliferation marker Ki-67. Kaplan-Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome. Small interfering RNA (siRNA) was used to silence spinophilin and to explore the effects of reduced spinophilin expression on cellular growth. RESULTS In our study, complete loss of spinophilin immunoreactivity was found in 44 of 104 HCCs (42.3%) and reduced levels were found in an additional 37 (35.6%) cases. After adjusting for other prognostic factors, multivariate Cox regression analysis identified low expression of spinophilin as an independent prognostic factor with respect to disease-free (hazard ratio (HR)=1.8; 95% confidence interval (CI)=1.04-3.40; P=0.043) and cancer-specific survival (HR=2.0; CI=1.1-3.8; P=0.025). Reduced spinophilin expression significantly correlated with higher Ki-67 index in HCC (P=0.014). Reducing spinophilin levels by siRNA induced a higher cellular growth rate and increased cyclin D2 expression in tumour cells (P<0.05). CONCLUSION This is the first study of the expression pattern and distribution of spinophilin in HCC. According to our data, the loss of spinophilin is associated with higher proliferation and might be useful as a prognostic marker in patients with HCC.
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Giza JI, Jung Y, Jeffrey RA, Neugebauer NM, Picciotto MR, Biederer T. The synaptic adhesion molecule SynCAM 1 contributes to cocaine effects on synapse structure and psychostimulant behavior. Neuropsychopharmacology 2013; 38:628-38. [PMID: 23169347 PMCID: PMC3572459 DOI: 10.1038/npp.2012.226] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 10/17/2012] [Accepted: 10/18/2012] [Indexed: 11/09/2022]
Abstract
Drugs of abuse have acute and persistent effects on synapse structure and addiction-related behaviors. Trans-synaptic interactions can control synapse development, and synaptic cell adhesion molecule (SynCAM) proteins (also named nectin-like molecules) are immunoglobulin adhesion proteins that span the synaptic cleft and induce excitatory synapses. Our studies now reveal that the loss of SynCAM 1 in knockout (KO) mice reduces excitatory synapse number in nucleus accumbens (NAc). SynCAM 1 additionally contributes to the structural remodeling of NAc synapses in response to the psychostimulant cocaine. Specifically, we find that cocaine administration increases the density of stubby spines on medium spiny neurons in NAc, and that maintaining this increase requires SynCAM 1. Furthermore, mushroom-type spines on these neurons are structurally more plastic when SynCAM 1 is absent, and challenging drug-withdrawn mice with cocaine shortens these spines in SynCAM 1 KO mice. These effects are correlated with changes on the behavioral level, where SynCAM 1 contributes to the psychostimulant effects of cocaine as measured after acute and repeated administration, and in drug-withdrawn mice. Together, our results provide evidence that the loss of a synapse-organizing adhesion molecule can modulate cocaine effects on spine structures in NAc and increases vulnerability to the behavioral actions of cocaine. SynCAM-dependent pathways may therefore represent novel points of therapeutic intervention after exposure to drugs of abuse.
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Affiliation(s)
- Joanna I Giza
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Yonwoo Jung
- Department of Psychiatry, Yale University Medical School, Yale University, New Haven, CT, USA
| | - Rachel A Jeffrey
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Nichole M Neugebauer
- Department of Psychiatry, Yale University Medical School, Yale University, New Haven, CT, USA
| | - Marina R Picciotto
- Department of Psychiatry, Yale University Medical School, Yale University, New Haven, CT, USA
| | - Thomas Biederer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
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Baucum AJ, Brown AM, Colbran RJ. Differential association of postsynaptic signaling protein complexes in striatum and hippocampus. J Neurochem 2013; 124:490-501. [PMID: 23173822 PMCID: PMC3557548 DOI: 10.1111/jnc.12101] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 11/19/2012] [Accepted: 11/20/2012] [Indexed: 02/03/2023]
Abstract
Distinct physiological stimuli are required for bidirectional synaptic plasticity in striatum and hippocampus, but differences in the underlying signaling mechanisms are poorly understood. We have begun to compare levels and interactions of key excitatory synaptic proteins in whole extracts and subcellular fractions isolated from micro-dissected striatum and hippocampus. Levels of multiple glutamate receptor subunits, calcium/calmodulin-dependent protein kinase II (CaMKII), a highly abundant serine/threonine kinase, and spinophilin, a F-actin and protein phosphatase 1 (PP1) binding protein, were significantly lower in striatal extracts, as well as in synaptic and/or extrasynaptic fractions, compared with similar hippocampal extracts/fractions. However, CaMKII interactions with spinophilin were more robust in striatum compared with hippocampus, and this enhanced association was restricted to the extrasynaptic fraction. NMDAR GluN2B subunits associate with both spinophilin and CaMKII, but spinophilin-GluN2B complexes were enriched in extrasynaptic fractions whereas CaMKII-GluN2B complexes were enriched in synaptic fractions. Notably, the association of GluN2B with both CaMKII and spinophilin was more robust in striatal extrasynaptic fractions compared with hippocampal extrasynaptic fractions. Selective differences in the assembly of synaptic and extrasynaptic signaling complexes may contribute to differential physiological regulation of excitatory transmission in striatum and hippocampus.
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Affiliation(s)
- Anthony J Baucum
- Department of Molecular Physiology and Biophysics, Vanderbilt Kennedy Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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37
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Jung Y, Mulholland PJ, Wiseman SL, Chandler LJ, Picciotto MR. Constitutive knockout of the membrane cytoskeleton protein beta adducin decreases mushroom spine density in the nucleus accumbens but does not prevent spine remodeling in response to cocaine. Eur J Neurosci 2012; 37:1-9. [PMID: 23106536 DOI: 10.1111/ejn.12037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 09/19/2012] [Accepted: 09/23/2012] [Indexed: 11/27/2022]
Abstract
The adducin family of proteins associates with the actin cytoskeleton in a calcium-dependent manner. Beta adducin (βAdd) is involved in synaptic plasticity in the hippocampus; however, the role of βAdd in synaptic plasticity in other brain areas is unknown. Using diolistic labeling with the lipophilic dye DiI, we found that the density of mature mushroom-shaped spines was significantly decreased in the nucleus accumbens (NAc) in brain slices from βAdd-knockout (KO) mice as compared to their wildtype (WT) siblings. The effect of 10 days of daily cocaine (15 mg/kg) administration on NAc spine number and locomotor behavior was also measured in βAdd WT and KO mice. As expected, there was a significant increase in overall spine density in NAc slices from cocaine-treated WT mice at this time-point; however, there was a greater increase in the density of mushroom spines in βAdd-KO animals following chronic cocaine administration than in WT. In addition, βAdd-KO mice showed elevated locomotor activity in response to cocaine treatment compared to WT siblings. These results indicate that βAdd is required for stabilising mature spines under basal conditions in the NAc, but that lack of this protein does not prevent synaptic remodeling following repeated cocaine administration. In addition, these data are consistent with previous studies suggesting that βAdd may normally be involved in stabilising spines once drug- or experience-dependent remodeling has occurred.
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Affiliation(s)
- Yonwoo Jung
- Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, CT 06508, USA
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Esteves SLC, Korrodi-Gregório L, Cotrim CZ, van Kleeff PJM, Domingues SC, da Cruz e Silva OAB, Fardilha M, da Cruz e Silva EF. Protein phosphatase 1γ isoforms linked interactions in the brain. J Mol Neurosci 2012; 50:179-97. [PMID: 23080069 DOI: 10.1007/s12031-012-9902-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/03/2012] [Indexed: 01/03/2023]
Abstract
Posttranslational protein modifications, in particular reversible protein phosphorylation, are important regulatory mechanisms involved in cellular signaling transduction pathways. Thousands of human proteins are phosphorylatable and the tight regulation of phosphorylation states is crucial for cell maintenance and development. Protein phosphorylation occurs primarily on serine, threonine, and tyrosine residues, through the antagonistic actions of protein kinases and phosphatases. The catalytic subunit of protein phosphatase 1 (PP1), a major Ser/Thr-phosphatase, associates with a large variety of regulatory subunits that define substrate specificity and determine specific cellular pathway responses. PP1 has been shown to bind to different proteins in the brain in order to execute key and differential functions. This work reports the identification of proteins expressed in the human brain that interact with PP1γ1 and PP1γ2 isoforms by the yeast two-hybrid method. An extensive search of PP1-binding motifs was performed for the proteins identified, revealing already known PP1 regulators but also novel interactors. Moreover, our results were integrated with the data of PP1γ interacting proteins from several public web databases, permitting the development of physical maps of the novel interactions. The PP1γ interactome thus obtained allowed for the identification of novel PP1 interacting proteins, supporting novel functions of PP1γ isoforms in the human brain.
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Affiliation(s)
- Sara L C Esteves
- Signal Transduction Laboratory, Centre for Cell Biology, Biology Department, University of Aveiro, 3810-193 Aveiro, Portugal
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Fourla DD, Papakonstantinou MP, Vrana SM, Georgoussi Z. Selective interactions of spinophilin with the C-terminal domains of the δ- and μ-opioid receptors and G proteins differentially modulate opioid receptor signaling. Cell Signal 2012; 24:2315-28. [PMID: 22922354 DOI: 10.1016/j.cellsig.2012.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/31/2012] [Accepted: 08/08/2012] [Indexed: 11/26/2022]
Abstract
Previous studies have shown that the intracellular domains of opioid receptors serve as platforms for the formation of a multi-component signaling complex consisting of various interacting partners (Leontiadis et al., 2009, Cell Signal. 21, 1218-1228; Georganta et al., 2010, Neuropharmacology, 59(3), 139-148). In the present study we demonstrate that spinophilin a dendritic-spine enriched scaffold protein associates with δ- and μ-opioid receptors (δ-ΟR, μ-OR) constitutively in HEK293 an interaction that is altered upon agonist administration and enhanced upon forskolin treatment for both μ-OR and δ-ΟR. Spinophilin association with the opioid receptors is mediated via the third intracellular loop and a conserved region of the C-terminal tails. The portion of spinophilin responsible for interaction with the δ-OR and μ-OR is narrowed to a region encompassing amino acids 151-444. Spinophilin, RGS4, Gα and Gβγ subunits of G proteins form a multi-protein complex using specific regions of spinophilin and a conserved amino acid stretch of the C-terminal tails of both δ-μ-ORs. Expression of spinophilin in HEK293 cells potentiated DPDPE-mediated adenylyl-cyclase inhibition of δ-OR leaving unaffected the levels of cAMP accumulation mediated by the μ-OR. Moreover, measurements of extracellular signal regulated kinase (ERK1,2) phosphorylation indicated that the presence of spinophilin attenuated agonist-driven ERK1,2 phosphorylation mediated upon activation of the δ-OR but not the μ-OR. Collectively, these findings suggest that spinophilin associates with both δ- and μ-ΟR and G protein subunits in HEK293 cells participating in a multimeric signaling complex that displays a differential regulatory role in opioid receptor signaling.
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Affiliation(s)
- Danai-Dionysia Fourla
- Laboratory of Cellular Signalling and Molecular Pharmacology, Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Athens, Greece
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Aguilar-Valles A, Jung S, Poole S, Flores C, Luheshi GN. Leptin and interleukin-6 alter the function of mesolimbic dopamine neurons in a rodent model of prenatal inflammation. Psychoneuroendocrinology 2012; 37:956-69. [PMID: 22133515 DOI: 10.1016/j.psyneuen.2011.11.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 10/07/2011] [Accepted: 11/04/2011] [Indexed: 12/21/2022]
Abstract
Maternal inflammation during critical stages of gestation is thought to underlie the link between prenatal infection and several neurodevelopmental psychiatric disorders in the offspring, including schizophrenia. Increased activity of mesolimbic dopamine (DA) neurons, a hallmark of psychosis, is found in offspring of rodents exposed to a prenatal inflammatory challenge but it is unclear how this effect is elicited. Using an experimental model of localized aseptic inflammation with turpentine oil (TURP) we sought to establish whether circulating interleukin-6 (IL-6) and leptin play a role in the effects of prenatal inflammation on DA neurons. Both mediators are involved in the systemic inflammatory response to immunogens, with IL-6 mediating the early phase, followed by leptin in the late phase of the response. Maternal treatment with TURP at gestational day (GD) 15 enhanced the locomotor response to the DA indirect agonist, amphetamine (AMPH), increased the expression of tyrosine hydroxylase (TH), an enzyme involved in DA synthesis, DA levels and the expression of the post-synaptic protein spinophilin in the nucleus accumbens (NAcc) in the adult offspring. All of these alterations were totally abolished by co-treating the pregnant dams with a neutralizing IL-6 antiserum. Neutralization of maternal leptin prevented the enhanced behavioral sensitization and elevation of DA and spinophilin in the NAcc but spared other changes regulated by IL-6, such as increased NAcc TH levels and acute locomotor response to AMPH. Our results provide novel evidence to suggest that prenatal surges in both maternal circulating IL-6 and leptin contribute to the appearance of sensitized DA function in the adult offspring.
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Affiliation(s)
- Argel Aguilar-Valles
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, 6875 LaSalle Boulevard, Montreal, Quebec, Canada.
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Neurabin scaffolding of adenosine receptor and RGS4 regulates anti-seizure effect of endogenous adenosine. J Neurosci 2012; 32:2683-95. [PMID: 22357852 DOI: 10.1523/jneurosci.4125-11.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Endogenous adenosine is an essential protective agent against neural damage by various insults to the brain. However, the therapeutic potential of adenosine receptor-directed ligands for neuroprotection is offset by side effects in peripheral tissues and organs. An increase in adenosine receptor responsiveness to endogenous adenosine would enhance neuroprotection while avoiding the confounding effects of exogenous ligands. Here we report novel regulation of adenosine-evoked responses by a neural tissue-specific protein, neurabin. Neurabin attenuated adenosine A(1) receptor (A1R) signaling by assembling a complex between the A1R and the regulator of G-protein signaling 4 (RGS4), a protein known to turn off G-protein signaling. Inactivation of the neurabin gene enhanced A1R signaling and promoted the protective effect of adenosine against excitotoxic seizure and neuronal death in mice. Furthermore, administration of a small molecule inhibitor of RGS4 significantly attenuated seizure severity in mice. Notably, the dose of kainate capable of inducing an ∼50% rate of death in wild-type (WT) mice did not affect neurabin-null mice or WT mice cotreated with an RGS4 inhibitor. The enhanced anti-seizure and neuroprotective effect achieved by disruption of the A1R/neurabin/RGS4 complex is elicited by the on-site and on-demand release of endogenous adenosine, and does not require administration of A1R ligands. These data identify neurabin-RGS4 as a novel tissue-selective regulatory mechanism for fine-tuning adenosine receptor function in the nervous system. Moreover, these findings implicate the A1R/neurabin/RGS4 complex as a valid therapeutic target for specifically manipulating the neuroprotective effects of endogenous adenosine.
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Sarrouilhe D, Ladeveze V. [When the curtain goes up on spinophilin's tumor suppressor function]. Med Sci (Paris) 2012; 28:26-8. [PMID: 22289823 DOI: 10.1051/medsci/2012281009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Denis Sarrouilhe
- Institut de Physiologie et Biologie Cellulaires, Pôle Biologie Santé, Université de Poitiers, CNRS UMR 6187, 40, Avenue du Recteur Pineau, Poitiers, 86022, France.
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A newly identified complex of spinophilin and the tyrosine phosphatase, SHP-1, modulates platelet activation by regulating G protein-dependent signaling. Blood 2011; 119:1935-45. [PMID: 22210881 DOI: 10.1182/blood-2011-10-387910] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelets are essential for normal hemostasis, but close regulation is required to avoid the destructive effects of either inappropriate platelet activation or excessive responses to injury. Here, we describe a novel complex comprising the scaffold protein, spinophilin (SPL), and the tyrosine phosphatase, SHP-1, and show that it can modulate platelet activation by sequestering RGS10 and RGS18, 2 members of the regulator of G protein signaling family. We also show that SPL/RGS/SHP1 complexes are present in resting platelets where constitutive phosphorylation of SPL(Y398) creates an atypical binding site for SHP-1. Activation of the SHP-1 occurs on agonist-induced phosphorylation of SHP-1(Y536), triggering dephosphorylation and decay of the SPL/RGS/SHP1 complex. Preventing SHP-1 activation blocks decay of the complex and produces a gain of function. Conversely, deleting spinophilin in mice inhibits platelet activation. It also attenuates the rise in platelet cAMP normally caused by endothelial prostacyclin (PGI(2)). Thus, we propose that the role of the SPL/RGS/SHP1 complex in platelets is time and context dependent. Before injury, the complex helps maintain the quiescence of circulating platelets by maximizing the impact of PGI(2). After injury, the complex gradually releases RGS proteins, limiting platelet activation and providing a mechanism for temporal coordination of pro thrombotic and antithrombotic inputs.
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Björk K, Svenningsson P. Modulation of monoamine receptors by adaptor proteins and lipid rafts: role in some effects of centrally acting drugs and therapeutic agents. Annu Rev Pharmacol Toxicol 2011; 51:211-42. [PMID: 20887195 DOI: 10.1146/annurev-pharmtox-010510-100520] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The monoamines and their cognate receptors are widespread in the central nervous system and are vital for normal brain function. Dysfunction in these systems underlies several psychiatric and neurological disease states, and consequently monoamines are targets of a host of pharmacotherapies. This review provides an overview on how monoamine receptors are regulated by adaptor proteins and lipid rafts with emphasis on interactions in nerve cells. Monoamine receptors have prominent intracellular loops that provide binding sites for adaptor proteins. Receptor function is further modulated by cholesterol and submembranous microdomains termed lipid rafts. These interactions determine several facets of G protein-coupled receptor (GPCR) function including trafficking, localization, and signaling. Possible roles of adaptor proteins and lipid rafts in disease states and in mediating actions of drugs and therapeutic agents are also discussed.
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Affiliation(s)
- Karl Björk
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
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45
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Berlanga ML, Price DL, Phung BS, Giuly R, Terada M, Yamada N, Cyr M, Caron MG, Laakso A, Martone ME, Ellisman MH. Multiscale imaging characterization of dopamine transporter knockout mice reveals regional alterations in spine density of medium spiny neurons. Brain Res 2011; 1390:41-9. [PMID: 21439946 DOI: 10.1016/j.brainres.2011.03.044] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 11/26/2022]
Abstract
The dopamine transporter knockout (DAT KO) mouse is a model of chronic hyperdopaminergia used to study a wide range of neuropsychiatric disorders such as schizophrenia, attention deficit hyperactivity disorder (ADHD), drug abuse, depression, and Parkinson's disease (PD). Early studies characterizing this mouse model revealed a subtle, but significant, decrease in the anterior striatal volume of DAT KO mice accompanied by a decrease in neuronal cell body numbers (Cyr et al., 2005). The present studies were conducted to examine medium spiny neuron (MSN) morphology by extending these earlier reports to include multiscale imaging studies using correlated light microscopy (LM) and electron microscopy (EM) techniques. Specifically, we set out to determine if chronic hyperdopaminergia results in quantifiable or qualitative changes in DAT KO mouse MSNs relative to wild-type (WT) littermates. Using Neurolucida Explorer's morphometric analysis, we measured spine density, dendritic length and synapse number at ages that correspond with the previously reported changes in striatal volume and progressive cell loss. Light microscopic analysis using Neurolucida tracings of photoconverted striatal MSNs revealed a highly localized loss of dendritic spines on the proximal portion of the dendrite (30 μm from the soma) in the DAT KO group. Next, thick sections containing MSN dendritic segments located at a distance of 20-60 μm from the cell soma, a region of the dendrite where spine density is reported to be the highest, were analyzed using electron microscope tomography (EMT). Because of the resolution limits of LM, the EM analysis was an extra measure taken to assure that our analysis included nearly all spines. Spine density measurements collected from the EMT data revealed only a modest decrease in the DAT KO group (n=3 mice) compared to age-matched WT controls (n=3 mice), a trend that supports the LM findings. Finally, a synaptic quantification using unbiased stereology did not detect a difference between DAT KO mice (n=6 mice) and WT controls (n=7 mice) at the EM level, supporting the focal nature of the early synaptic loss. These findings suggest that DAT KO mice have MSNs with highly localized spine loss and not an overall morphologically distinct cell shape. The characterization of morphological changes in DAT KO mice may provide information about the neural substrates underlying altered behaviors in these mice, with relevance for human neurological disorders thought to involve altered dopaminergic homeostasis. Results from this study also indicate the difficulty in correlating structural changes across scales, as the results on fine structure revealed thus far are subtle and non-uniform across striatal MSNs. The complexities associated with multiscale studies are driving the development of shared online informatics resources by gaining access to data where it is being analyzed.
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Affiliation(s)
- M L Berlanga
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA 92093-0608, USA.
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Kim SS, Wang H, Li XY, Chen T, Mercaldo V, Descalzi G, Wu LJ, Zhuo M. Neurabin in the anterior cingulate cortex regulates anxiety-like behavior in adult mice. Mol Brain 2011; 4:6. [PMID: 21247477 PMCID: PMC3037880 DOI: 10.1186/1756-6606-4-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 01/19/2011] [Indexed: 12/11/2022] Open
Abstract
Affective disorders, which include anxiety and depression, are highly prevalent and have overwhelming emotional and physical symptoms. Despite human brain imaging studies, which have implicated the prefrontal cortex including the anterior cingulate cortex (ACC), little is known about the ACC in anxiety disorders. Here we show that the ACC does modulate anxiety-like behavior in adult mice, and have identified a protein that is critical for this modulation. Absence of neurabin, a cytoskeletal protein, resulted in reduced anxiety-like behavior and increased depression-like behavior. Selective inhibition of neurabin in the ACC reproduced the anxiety but not the depression phenotype. Furthermore, loss of neurabin increased the presynaptic release of glutamate and cingulate neuronal excitability. These findings reveal novel roles of the ACC in anxiety disorders, and provide a new therapeutic target for the treatment of anxiety disorders.
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Affiliation(s)
- Susan S Kim
- Department of Physiology, Faculty of Medicine, University of Toronto Centre for the Study of Pain, ON, Canada
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Ragusa MJ, Dancheck B, Critton DA, Nairn AC, Page R, Peti W. Spinophilin directs protein phosphatase 1 specificity by blocking substrate binding sites. Nat Struct Mol Biol 2010; 17:459-64. [PMID: 20305656 PMCID: PMC2924587 DOI: 10.1038/nsmb.1786] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 02/08/2010] [Indexed: 01/14/2023]
Abstract
The serine/threonine Protein Phosphatase 1 (PP1) dephosphorylates hundreds of key biological targets. PP1 associates with ≥200 regulatory proteins to form highly specific holoenzymes. These regulatory proteins target PP1 to its point of action within the cell and prime its enzymatic specificity for particular substrates. However, how they direct PP1’s specificity is not understood. Here we show that spinophilin, a neuronal PP1 regulator, is entirely unstructured in its unbound form and binds PP1, through a folding-upon-binding mechanism, in an elongated fashion, blocking one of PP1’s three putative substrate binding sites, without altering its active site. This mode of binding is sufficient for spinophilin to restrict PP1’s activity toward a model substrate in vitro, without affecting its ability to dephosphorylate its neuronal substrate GluR1. Thus, our work provides the molecular basis for the ability of spinophilin to dictate PP1 substrate specificity.
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Affiliation(s)
- Michael J Ragusa
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island, USA
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Baucum AJ, Jalan-Sakrikar N, Jiao Y, Gustin RM, Carmody LC, Tabb DL, Ham AJL, Colbran RJ. Identification and validation of novel spinophilin-associated proteins in rodent striatum using an enhanced ex vivo shotgun proteomics approach. Mol Cell Proteomics 2010; 9:1243-59. [PMID: 20124353 DOI: 10.1074/mcp.m900387-mcp200] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Spinophilin regulates excitatory postsynaptic function and morphology during development by virtue of its interactions with filamentous actin, protein phosphatase 1, and a plethora of additional signaling proteins. To provide insight into the roles of spinophilin in mature brain, we characterized the spinophilin interactome in subcellular fractions solubilized from adult rodent striatum by using a shotgun proteomics approach to identify proteins in spinophilin immune complexes. Initial analyses of samples generated using a mouse spinophilin antibody detected 23 proteins that were not present in an IgG control sample; however, 12 of these proteins were detected in complexes isolated from spinophilin knock-out tissue. A second screen using two different spinophilin antibodies and either knock-out or IgG controls identified a total of 125 proteins. The probability of each protein being specifically associated with spinophilin in each sample was calculated, and proteins were ranked according to a chi(2) analysis of the probabilities from analyses of multiple samples. Spinophilin and the known associated proteins neurabin and multiple isoforms of protein phosphatase 1 were specifically detected. Multiple, novel, spinophilin-associated proteins (myosin Va, calcium/calmodulin-dependent protein kinase II, neurofilament light polypeptide, postsynaptic density 95, alpha-actinin, and densin) were then shown to interact with GST fusion proteins containing fragments of spinophilin. Additional biochemical and transfected cell imaging studies showed that alpha-actinin and densin directly interact with residues 151-300 and 446-817, respectively, of spinophilin. Taken together, we have developed a multi-antibody, shotgun proteomics approach to characterize protein interactomes in native tissues, delineating the importance of knock-out tissue controls and providing novel insights into the nature and function of the spinophilin interactome in mature striatum.
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Affiliation(s)
- Anthony J Baucum
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232-0615, USA.
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Lebel M, Chagniel L, Bureau G, Cyr M. Striatal inhibition of PKA prevents levodopa-induced behavioural and molecular changes in the hemiparkinsonian rat. Neurobiol Dis 2010; 38:59-67. [PMID: 20060905 DOI: 10.1016/j.nbd.2009.12.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 11/19/2009] [Accepted: 12/30/2009] [Indexed: 11/20/2022] Open
Abstract
l-3,4-dihydroxyphenylalanine methyl ester hydrochloride (l-DOPA) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of abnormal involuntary movements (AIMS) known as l-DOPA-induced dyskinesias (LID). The molecular changes underlying LID are not completely understood. Using the 6-hydroxydopamine-lesioned rat model of PD, we showed that l-DOPA elicits profound alterations in the activity of three LID molecular markers, namely DeltaFosB, dopamine, cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), as well as in phosphorylation levels of the cytoskeletal-associated protein tau. These modifications are triggered by protein kinase A (PKA) activation and intermittent stimulation of dopamine receptors as they are totally prevented by intrastriatal injections of Rp-cAMPS, a PKA inhibitor, or by continuous administration of l-DOPA via subcutaneous mini-pump. Importantly, Rp-cAMPS does not modulate the positive effect of l-DOPA on locomotor deficits and significantly attenuates the emergence of AIMS in 6-hydroxydopamine hydrobromide-lesioned rats. Even if decreased PKA signalling in the striatum may represent a clinical challenge, these data provide novel evidence that PKA activation, through modification of striatal signalling and alterations of cytoskeletal constituents, plays a key role in the manifestation of LID.
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Affiliation(s)
- Manon Lebel
- Groupe de recherche en neurosciences, Département de chimie-biologie, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC, Canada G9A 5H7
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50
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Hedges VL, Chakravarty S, Nestler EJ, Meisel RL. Delta FosB overexpression in the nucleus accumbens enhances sexual reward in female Syrian hamsters. GENES BRAIN AND BEHAVIOR 2009; 8:442-9. [PMID: 19566711 DOI: 10.1111/j.1601-183x.2009.00491.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Repeated activation of the mesolimbic dopamine system results in persistent behavioral alterations accompanied by a pattern of neural plasticity in the nucleus accumbens (NAc). As the accumulation of the transcription factor Delta FosB may be an important component of this plasticity, the question addressed in our research is whether Delta FosB is regulated by sexual experience in females. We have shown that female Syrian hamsters, given sexual experience, exhibit several behavioral alterations including increased sexual efficiency with naïve male hamsters, sexual reward and enhanced responsiveness to psychomotor stimulants (e.g. amphetamine). We recently demonstrated that sexual experience increased the levels of Delta FosB in the NAc of female Syrian hamsters. The focus of this study was to explore the functional consequences of this induction by determining if the constitutive overexpression of Delta FosB by adeno-associated virus (AAV) vectors in the NAc could mimic the behavioral effects of sexual experience. Animals with AAV-mediated overexpression of Delta FosB in the NAc showed evidence of sexual reward in a conditioned place preference paradigm under conditions in which control animals receiving an injection of AAV-green fluorescent protein (GFP) into the NAc did not. Sexual behavior tests further showed that males paired with the AAV-Delta FosB females had increased copulatory efficiency as measured by the proportion of mounts that included intromission compared to males mated with the AAV-GFP females. These results support a role for Delta FosB in mediating natural motivated behaviors, in this case female sexual behavior, and provide new insight into the possible endogenous actions of Delta FosB.
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Affiliation(s)
- V L Hedges
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
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