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Zhang W, Wang X, Yu M, Li JA, Meng H. The c-Jun N-terminal kinase signaling pathway in epilepsy: activation, regulation, and therapeutics. J Recept Signal Transduct Res 2019; 38:492-498. [PMID: 31038026 DOI: 10.1080/10799893.2019.1590410] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epilepsy affects approximately 50-70 million people worldwide and 30-40% of patients do not benefit from medication. Therefore, it is necessary to identify novel targets for epileptic treatments. c-Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase (MAPK) family that activates diverse substrates, such as transcriptional factors, adaptor proteins, and signaling proteins, and has a wide variety of functions in both physiological and pathological conditions. The excessive activation of JNK is found not only in the acute phase of epilepsy, but also in the chronic phase, which potentiates it as a promising target in epilepsy control. In this review, we discuss the activation of the JNK pathway in epilepsy and its role in neuronal death, astrocyte activation, and mossy fiber sprouting (MFS) based on recent updates. Finally, we briefly introduce the current agents that target JNK signaling to control epilepsy.
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Affiliation(s)
- Wuqiong Zhang
- a Department of Neurology and Neuroscience center , The First Hospital of Jilin University , Changchun , P. R. China
| | - Xue Wang
- a Department of Neurology and Neuroscience center , The First Hospital of Jilin University , Changchun , P. R. China
| | - Miaomiao Yu
- a Department of Neurology and Neuroscience center , The First Hospital of Jilin University , Changchun , P. R. China
| | - Jia-Ai Li
- a Department of Neurology and Neuroscience center , The First Hospital of Jilin University , Changchun , P. R. China
| | - Hongmei Meng
- a Department of Neurology and Neuroscience center , The First Hospital of Jilin University , Changchun , P. R. China
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2
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Zhang L, Zhang P, Wang G, Zhang H, Zhang Y, Yu Y, Zhang M, Xiao J, Crespo P, Hell JW, Lin L, Huganir RL, Zhu JJ. Ras and Rap Signal Bidirectional Synaptic Plasticity via Distinct Subcellular Microdomains. Neuron 2018; 98:783-800.e4. [PMID: 29706584 PMCID: PMC6192044 DOI: 10.1016/j.neuron.2018.03.049] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/12/2018] [Accepted: 03/27/2018] [Indexed: 11/16/2022]
Abstract
How signaling molecules achieve signal diversity and specificity is a long-standing cell biology question. Here we report the development of a targeted delivery method that permits specific expression of homologous Ras-family small GTPases (i.e., Ras, Rap2, and Rap1) in different subcellular microdomains, including the endoplasmic reticulum, lipid rafts, bulk membrane, lysosomes, and Golgi complex, in rodent hippocampal CA1 neurons. The microdomain-targeted delivery, combined with multicolor fluorescence protein tagging and high-resolution dual-quintuple simultaneous patch-clamp recordings, allows systematic analysis of microdomain-specific signaling. The analysis shows that Ras signals long-term potentiation via endoplasmic reticulum PI3K and lipid raft ERK, whereas Rap2 and Rap1 signal depotentiation and long-term depression via bulk membrane JNK and lysosome p38MAPK, respectively. These results establish an effective subcellular microdomain-specific targeted delivery method and unveil subcellular microdomain-specific signaling as the mechanism for homologous Ras and Rap to achieve signal diversity and specificity to control multiple forms of synaptic plasticity.
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Affiliation(s)
- Lei Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Peng Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Guangfu Wang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Huaye Zhang
- Department of Microbiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Yajun Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yilin Yu
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mingxu Zhang
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Jian Xiao
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabriaand CIBERONC, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Cantabria, Santander 39011, Spain
| | - Johannes W Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Li Lin
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China.
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China; School of Medicine, Ningbo University, Ningbo 315010, China; Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, the Netherlands
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Abstract
The c-Jun N-terminal kinase (JNK) signal transduction pathway is implicated in learning and memory. Here, we examined the role of JNK activation mediated by the JNK-interacting protein 1 (JIP1) scaffold protein. We compared male wild-type mice with a mouse model harboring a point mutation in the Jip1 gene that selectively blocks JIP1-mediated JNK activation. These male mutant mice exhibited increased NMDAR currents, increased NMDAR-mediated gene expression, and a lower threshold for induction of hippocampal long-term potentiation. The JIP1 mutant mice also displayed improved hippocampus-dependent spatial memory and enhanced associative fear conditioning. These results were confirmed using a second JIP1 mutant mouse model that suppresses JNK activity. Together, these observations establish that JIP1-mediated JNK activation contributes to the regulation of hippocampus-dependent, NMDAR-mediated synaptic plasticity and learning.SIGNIFICANCE STATEMENT The results of this study demonstrate that c-Jun N-terminal kinase (JNK) activation induced by the JNK-interacting protein 1 (JIP1) scaffold protein negatively regulates the threshold for induction of long-term synaptic plasticity through the NMDA-type glutamate receptor. This change in plasticity threshold influences learning. Indeed, mice with defects in JIP1-mediated JNK activation display enhanced memory in hippocampus-dependent tasks, such as contextual fear conditioning and Morris water maze, indicating that JIP1-JNK constrains spatial memory. This study identifies JIP1-mediated JNK activation as a novel molecular pathway that negatively regulates NMDAR-dependent synaptic plasticity and memory.
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Sodero AO, Rodriguez-Silva M, Salio C, Sassoè-Pognetto M, Chambers JW. Sab is differentially expressed in the brain and affects neuronal activity. Brain Res 2017; 1670:76-85. [PMID: 28606781 DOI: 10.1016/j.brainres.2017.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/01/2017] [Accepted: 06/03/2017] [Indexed: 01/27/2023]
Abstract
Sab (SH3 binding protein 5 or SH3BP5) is a mitochondrial scaffold protein involved in signaling associated with mitochondrial dysfunction and apoptosis; furthermore, Sab is a crucial signaling platform for neurodegenerative disease. To determine how this signaling nexus could have a significant effect on disease, we examined the regional abundance of Sab in the brain and sub-neuronal distribution, and we monitored the effect of Sab-mediated signaling on neuronal activity. We found that Sab is widely expressed in the adult mouse brain with increased abundance in hippocampus, ventral midbrain, and cerebellum. Sab was found in purified synaptosomes and in cultures of hippocampal neurons and astrocytes. Confocal and electron microscopy of mouse hippocampal sections confirmed the mitochondrial localization of Sab in the soma, dendrites, and axons. Given the localization and sub-neuronal distribution of Sab, we postulated that Sab-mediated signaling could affect neuronal function, so we measured the impact of inhibiting Sab-mediated events on the spontaneous activity in cultured hippocampal neurons. Treatment with a Sab-inhibitory peptide (Tat-SabKIM1), but not a scrambled control peptide, decreased the firing frequency and spike amplitudes. Our results demonstrate that brain-specific Sab-mediated signaling plays a role in neuronal activity through the manipulation of mitochondrial physiology by interacting kinases.
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Affiliation(s)
- Alejandro O Sodero
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States
| | - Monica Rodriguez-Silva
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Italy
| | | | - Jeremy W Chambers
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States; Department of Neuroscience, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States; Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, United States.
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Evidence of Presynaptic Localization and Function of the c-Jun N-Terminal Kinase. Neural Plast 2017; 2017:6468356. [PMID: 28367336 PMCID: PMC5359460 DOI: 10.1155/2017/6468356] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/28/2016] [Accepted: 12/15/2016] [Indexed: 12/17/2022] Open
Abstract
The c-Jun N-terminal kinase (JNK) is part of a stress signalling pathway strongly activated by NMDA-stimulation and involved in synaptic plasticity. Many studies have been focused on the post-synaptic mechanism of JNK action, and less is known about JNK presynaptic localization and its physiological role at this site. Here we examined whether JNK is present at the presynaptic site and its activity after presynaptic NMDA receptors stimulation. By using N-SIM Structured Super Resolution Microscopy as well as biochemical approaches, we demonstrated that presynaptic fractions contained significant amount of JNK protein and its activated form. By means of modelling design, we found that JNK, via the JBD domain, acts as a physiological effector on T-SNARE proteins; then using biochemical approaches we demonstrated the interaction between Syntaxin-1-JNK, Syntaxin-2-JNK, and Snap25-JNK. In addition, taking advance of the specific JNK inhibitor peptide, D-JNKI1, we defined JNK action on the SNARE complex formation. Finally, electrophysiological recordings confirmed the role of JNK in the presynaptic modulation of vesicle release. These data suggest that JNK-dependent phosphorylation of T-SNARE proteins may have an important functional role in synaptic plasticity.
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Sheng Y, Zhang L, Su SC, Tsai LH, Julius Zhu J. Cdk5 is a New Rapid Synaptic Homeostasis Regulator Capable of Initiating the Early Alzheimer-Like Pathology. Cereb Cortex 2016; 26:2937-51. [PMID: 26088971 PMCID: PMC4898661 DOI: 10.1093/cercor/bhv032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cyclin-dependent kinase 5 (Cdk5) is a serine/threonine kinase implicated in synaptic plasticity, behavior, and cognition, yet its synaptic function remains poorly understood. Here, we report that physiological Cdk5 signaling in rat hippocampal CA1 neurons regulates homeostatic synaptic transmission using an unexpectedly rapid mechanism that is different from all known slow homeostatic regulators, such as beta amyloid (Aβ) and activity-regulated cytoskeleton-associated protein (Arc, aka Arg3.1). Interestingly, overproduction of the potent Cdk5 activator p25 reduces synapse density, and dynamically regulates synaptic size by suppressing or enhancing Aβ/Arc production. Moreover, chronic overproduction of p25, seen in Alzheimer's patients, induces initially concurrent reduction in synapse density and increase in synaptic size characteristic of the early Alzheimer-like pathology, and later persistent synapse elimination in intact brains. These results identify Cdk5 as the regulator of a novel rapid form of homeostasis at central synapses and p25 as the first molecule capable of initiating the early Alzheimer's synaptic pathology.
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Affiliation(s)
- Yanghui Sheng
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- Undergraduate Class of 2011, Yuanpei Honors College, Peking University, Beijing100871, China
- Current address: Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Lei Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Susan C. Su
- Picower Institute for Learning and Memory and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory and Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - J. Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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Sen A, Hongpaisan J, Wang D, Nelson TJ, Alkon DL. Protein Kinase Cϵ (PKCϵ) Promotes Synaptogenesis through Membrane Accumulation of the Postsynaptic Density Protein PSD-95. J Biol Chem 2016; 291:16462-76. [PMID: 27330081 DOI: 10.1074/jbc.m116.730440] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Indexed: 11/06/2022] Open
Abstract
Protein kinase Cϵ (PKCϵ) promotes synaptic maturation and synaptogenesis via activation of synaptic growth factors such as BDNF, NGF, and IGF. However, many of the detailed mechanisms by which PKCϵ induces synaptogenesis are not fully understood. Accumulation of PSD-95 to the postsynaptic density (PSD) is known to lead to synaptic maturation and strengthening of excitatory synapses. Here we investigated the relationship between PKCϵ and PSD-95. We show that the PKCϵ activators dicyclopropanated linoleic acid methyl ester and bryostatin 1 induce phosphorylation of PSD-95 at the serine 295 residue, increase the levels of PSD-95, and enhance its membrane localization. Elimination of the serine 295 residue in PSD-95 abolished PKCϵ-induced membrane accumulation. Knockdown of either PKCϵ or JNK1 prevented PKCϵ activator-mediated membrane accumulation of PSD-95. PKCϵ directly phosphorylated PSD-95 and JNK1 in vitro Inhibiting PKCϵ, JNK, or calcium/calmodulin-dependent kinase II activity prevented the effects of PKCϵ activators on PSD-95 phosphorylation. Increase in membrane accumulation of PKCϵ and phosphorylated PSD-95 (p-PSD-95(S295)) coincided with an increased number of synapses and increased amplitudes of excitatory post-synaptic potentials (EPSPs) in adult rat hippocampal slices. Knockdown of PKCϵ also reduced the synthesis of PSD-95 and the presynaptic protein synaptophysin by 30 and 44%, respectively. Prolonged activation of PKCϵ increased synapse number by 2-fold, increased presynaptic vesicle density, and greatly increased PSD-95 clustering. These results indicate that PKCϵ promotes synaptogenesis by activating PSD-95 phosphorylation directly through JNK1 and calcium/calmodulin-dependent kinase II and also by inducing expression of PSD-95 and synaptophysin.
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Affiliation(s)
- Abhik Sen
- From the Blanchette Rockefeller Neurosciences Institute, Morgantown, West Virginia 26505
| | - Jarin Hongpaisan
- From the Blanchette Rockefeller Neurosciences Institute, Morgantown, West Virginia 26505
| | - Desheng Wang
- From the Blanchette Rockefeller Neurosciences Institute, Morgantown, West Virginia 26505
| | - Thomas J Nelson
- From the Blanchette Rockefeller Neurosciences Institute, Morgantown, West Virginia 26505
| | - Daniel L Alkon
- From the Blanchette Rockefeller Neurosciences Institute, Morgantown, West Virginia 26505
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Activation of α7 nicotinic acetylcholine receptors protects potentiated synapses from depotentiation during theta pattern stimulation in the hippocampal CA1 region of rats. Neuropharmacology 2016; 105:378-387. [PMID: 26867505 DOI: 10.1016/j.neuropharm.2016.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/24/2016] [Accepted: 02/05/2016] [Indexed: 11/21/2022]
Abstract
Long-term potentiation (LTP) shows memory-like consolidation and thus becomes increasingly resistant to disruption by low-frequency stimulation (LFS). However, it is known that nicotine application during LFS uniquely depotentiates consolidated LTP. Here, we investigated how nicotine contributes to the disruption of stabilized LTP in the hippocampal CA1 region. We found that nicotine-induced depotentiation is not due to masking LTP by inducing long-term depression and requires the activation of GluN2A-containing NMDARs. We further examined whether nicotine-induced depotentiation involves the reversal of LTP mechanisms. LTP causes phosphorylation of Ser-831 on GluA1 subunits of AMPARs that increases the single-channel conductance of AMPARs. This phosphorylation remained unchanged after depotentiation. LTP involves the insertion of new AMPARs into the synapse and the internalization of AMPARs is associated with dephosphorylation of Ser-845 on GluA1 and caspase-3 activity. Nicotine-induced depotentiation occurred without dephosphorylation of the Ser-845 and in the presence of a caspase-3 inhibitor. LTP is also accompanied by increased filamentous actin (F-actin), which controls spine size. Nicotine-induced depotentiation was prevented by jasplakinolide, which stabilizes F-actin, suggesting that nicotine depotentiates consolidated LTP by destabilizing F-actin. α7 nicotinic acetylcholine receptor (nAChR) antagonists mimicked the effect of nicotine and selective removal of hippocampal cholinergic input caused depotentiation in the absence of nicotine, suggesting that nicotine depotentiates consolidated LTP by inducing α7 nAChR desensitization. Our results demonstrate a new role for nicotinic cholinergic systems in protecting potentiated synapses from depotentiation by preventing GluN2A-NMDAR-mediated signaling for actin destabilization.
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10
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Kemp A, Tischmeyer W, Manahan-Vaughan D. Learning-facilitated long-term depression requires activation of the immediate early gene, c-fos, and is transcription dependent. Behav Brain Res 2013; 254:83-91. [DOI: 10.1016/j.bbr.2013.04.036] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/16/2013] [Accepted: 04/22/2013] [Indexed: 12/23/2022]
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Abstract
Neuronal nitric oxide synthase (nNOS) and p38MAPK are strongly implicated in excitotoxicity, a mechanism common to many neurodegenerative conditions, but the intermediary mechanism is unclear. NOS1AP is encoded by a gene recently associated with sudden cardiac death, diabetes-associated complications, and schizophrenia (Arking et al., 2006; Becker et al., 2008; Brzustowicz, 2008; Lehtinen et al., 2008). Here we find it interacts with p38MAPK-activating kinase MKK3. Excitotoxic stimulus induces recruitment of NOS1AP to nNOS in rat cortical neuron culture. Excitotoxic activation of p38MAPK and subsequent neuronal death are reduced by competing with the nNOS:NOS1AP interaction and by knockdown with NOS1AP-targeting siRNAs. We designed a cell-permeable peptide that competes for the unique PDZ domain of nNOS that interacts with NOS1AP. This peptide inhibits NMDA-induced recruitment of NOS1AP to nNOS and in vivo in rat, doubles surviving tissue in a severe model of neonatal hypoxia-ischemia, a major cause of neonatal death and pediatric disability. The highly unusual sequence specificity of the nNOS:NOS1AP interaction and involvement in excitotoxic signaling may provide future opportunities for generation of neuroprotectants with high specificity.
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Arf6-GEF BRAG1 regulates JNK-mediated synaptic removal of GluA1-containing AMPA receptors: a new mechanism for nonsyndromic X-linked mental disorder. J Neurosci 2012; 32:11716-26. [PMID: 22915114 DOI: 10.1523/jneurosci.1942-12.2012] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activity-dependent modifications of excitatory synapses contribute to synaptic maturation and plasticity, and are critical for learning and memory. Consequently, impairments in synapse formation or synaptic transmission are thought to be responsible for several types of mental disabilities. BRAG1 is a guanine nucleotide exchange factor for the small GTP-binding protein Arf6 that localizes to the postsynaptic density of excitatory synapses. Mutations in BRAG1 have been identified in families with X-linked intellectual disability (XLID). These mutations mapped to either the catalytic domain or an IQ-like motif; however, the pathophysiological basis of these mutations remains unknown. Here, we show that the BRAG1 IQ motif binds apo-calmodulin (CaM), and that calcium-induced CaM release triggers a reversible conformational change in human BRAG1. We demonstrate that BRAG1 activity, stimulated by activation of NMDA-sensitive glutamate receptors, depresses AMPA receptor (AMPA-R)-mediated transmission via JNK-mediated synaptic removal of GluA1-containing AMPA-Rs in rat hippocampal neurons. Importantly, a BRAG1 mutant that fails to activate Arf6 also fails to depress AMPA-R signaling, indicating that Arf6 activity is necessary for this process. Conversely, a mutation in the BRAG1 IQ-like motif that impairs CaM binding results in hyperactivation of Arf6 signaling and constitutive depression of AMPA transmission. Our findings reveal a role for BRAG1 in response to neuronal activity with possible clinical relevance to nonsyndromic XLID.
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Seo J, Hong J, Lee SJ, Choi SY. c-Jun N-terminal phosphorylation is essential for hippocampal synaptic plasticity. Neurosci Lett 2012; 531:14-9. [PMID: 23041047 DOI: 10.1016/j.neulet.2012.09.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 11/30/2022]
Abstract
c-Jun N-terminal kinase (JNK), a member of the MAPK family, is an important regulatory factor of synaptic plasticity as well as neuronal differentiation and cell death. Recently, JNK has been reported to modulate synaptic plasticity by the direct phosphorylation of synaptic proteins. The specific role of c-Jun phosphorylation in JNK mediated synaptic plasticity, however, remains unclear. In this study, we investigated the effects of c-Jun phosphorylation on synaptic structure and function by using c-Jun mutant mice, c-JunAA, in which the active phosphorylation sites at serines 63 and 73 were replaced by alanines. The gross hippocampal anatomy and number of spines on hippocampal pyramidal neurons were normal in c-JunAA mice. Basal synaptic transmission, input-output ratios, and paired-pulse facilitation (PPF) were also no different in c-JunAA compared with wild-type mice. Notably, however, the induction of long-term potentiation (LTP) at hippocampal CA3-CA1 synapses in c-JunAA mice was impaired, whereas induction of long-term depression (LTD) was normal. These data suggest that phosphorylation of the c-Jun N-terminus is required for LTP formation in the hippocampus, and may help to better characterize JNK-mediated modulation of synaptic plasticity.
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Affiliation(s)
- Jinsoo Seo
- Department of Physiology and Dental Research Institute, Seoul National University School of Dentistry, Seoul 110-749, South Korea
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Winchester CL, Ohzeki H, Vouyiouklis DA, Thompson R, Penninger JM, Yamagami K, Norrie JD, Hunter R, Pratt JA, Morris BJ. Converging evidence that sequence variations in the novel candidate gene MAP2K7 (MKK7) are functionally associated with schizophrenia. Hum Mol Genet 2012; 21:4910-21. [DOI: 10.1093/hmg/dds331] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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