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Malone TJ, Wu J, Zhang Y, Licznerski P, Chen R, Nahiyan S, Pedram M, Jonas EA, Kaczmarek LK. Neuronal potassium channel activity triggers initiation of mRNA translation through binding of translation regulators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.07.579306. [PMID: 38370631 PMCID: PMC10871293 DOI: 10.1101/2024.02.07.579306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Neuronal activity stimulates mRNA translation crucial for learning and development. While FMRP (Fragile X Mental Retardation Protein) and CYFIP1 (Cytoplasmic FMR1 Interacting Protein 1) regulate translation, the mechanism linking translation to neuronal activity is not understood. We now find that translation is stimulated when FMRP and CYFIP1 translocate to the potassium channel Slack (KCNT1, Slo2.2). When Slack is activated, both factors are released from eIF4E (Eukaryotic Initiation Factor 4E), where they normally inhibit translation initiation. A constitutively active Slack mutation and pharmacological stimulation of the wild-type channel both increase binding of FMRP and CYFIP1 to the channel, enhancing the translation of a reporter for β-actin mRNA in cell lines and the synthesis of β-actin in neuronal dendrites. Slack activity-dependent translation is abolished when both FMRP and CYFIP1 expression are suppressed. The effects of Slack mutations on activity-dependent translation may explain the severe intellectual disability produced by these mutations in humans. HIGHLIGHTS Activation of Slack channels triggers translocation of the FMRP/CYFIP1 complexSlack channel activation regulates translation initiation of a β-actin reporter constructA Slack gain-of-function mutation increases translation of β-actin reporter construct and endogenous cortical β-actinFMRP and CYFIP1 are required for Slack activity-dependent translation. IN BRIEF Malone et al . show that the activation of Slack channels triggers translocation of the FMRP/CYFIP1 complex from the translation initiation factor eIF4E to the channel. This translocation releases eIF4E and stimulates mRNA translation of a reporter for β-actin and cortical β-actin mRNA, elucidating the mechanism that connects neuronal activity with translational regulation.
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2
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Temi S, Rudyk C, Armstrong J, Landrigan JA, Dedek C, Salmaso N, Hildebrand ME. Differential expression of GluN2 NMDA receptor subunits in the dorsal horn of male and female rats. Channels (Austin) 2021; 15:179-192. [PMID: 33509021 PMCID: PMC7849732 DOI: 10.1080/19336950.2020.1871205] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/01/2020] [Accepted: 12/29/2020] [Indexed: 02/02/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are excitatory ionotropic glutamate receptors expressed throughout the CNS, including in the spinal dorsal horn. The GluN2 subtypes of NMDAR subunit, which include GluN2A, GluN2B, and GluN2D in the dorsal horn, confer NMDARs with structural and functional variability, enabling heterogeneity in synaptic transmission and plasticity. Despite essential roles for NMDARs in physiological and pathological pain processing, the distribution and function of these specific GluN2 isoforms across dorsal horn laminae remain poorly understood. Surprisingly, there is a complete lack of knowledge of GluN2 expression in female rodents. We, therefore, investigated the relative expression of specific GluN2 variants in the dorsal horn of lumbar (L4/L5) spinal cord from both male and female rats. In order to detect synaptic GluN2 isoforms, we used pepsin antigen-retrieval to unmask these highly cross-linked protein complexes. We found that GluN2B and GluN2D are preferentially localized to the pain-processing superficial regions of the dorsal horn in males, while only GluN2B is predominantly localized to the superficial dorsal horn of female rats. The GluN2A subunit is diffusely localized to neuropil throughout the dorsal horn of both males and females, while GluN2B and GluN2D immunolabelling are found both in the neuropil and on the soma of dorsal horn neurons. Finally, we identified an unexpected enhanced expression of GluN2B in the medial division of the superficial dorsal horn, but in males only. These sex-specific localization patterns of GluN2-NMDAR subunits across dorsal horn laminae have significant implications for the understanding of divergent spinal mechanisms of pain processing.
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Affiliation(s)
- Santa Temi
- Department of Neuroscience, Carleton University, Ottawa, Canada
| | | | | | | | - Chris Dedek
- Department of Neuroscience, Carleton University, Ottawa, Canada
| | | | - Michael E. Hildebrand
- Department of Neuroscience, Carleton University, Ottawa, Canada
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
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3
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Yong XLH, Zhang L, Yang L, Chen X, Tan JZA, Yu X, Chandra M, Livingstone E, Widagdo J, Vieira MM, Roche KW, Lynch JW, Keramidas A, Collins BM, Anggono V. Regulation of NMDA receptor trafficking and gating by activity-dependent CaMKIIα phosphorylation of the GluN2A subunit. Cell Rep 2021; 36:109338. [PMID: 34233182 PMCID: PMC8313361 DOI: 10.1016/j.celrep.2021.109338] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/19/2021] [Accepted: 06/11/2021] [Indexed: 01/23/2023] Open
Abstract
NMDA receptor (NMDAR)-dependent Ca2+ influx underpins multiple forms of synaptic plasticity. Most synaptic NMDAR currents in the adult forebrain are mediated by GluN2A-containing receptors, which are rapidly inserted into synapses during long-term potentiation (LTP); however, the underlying molecular mechanisms remain poorly understood. In this study, we show that GluN2A is phosphorylated at Ser-1459 by Ca2+/calmodulin-dependent kinase IIα (CaMKIIα) in response to glycine stimulation that mimics LTP in primary neurons. Phosphorylation of Ser-1459 promotes GluN2A interaction with the sorting nexin 27 (SNX27)-retromer complex, thereby enhancing the endosomal recycling of NMDARs. Loss of SNX27 or CaMKIIα function blocks the glycine-induced increase in GluN2A-NMDARs on the neuronal membrane. Interestingly, mutations of Ser-1459, including the rare S1459G human epilepsy variant, prolong the decay times of NMDAR-mediated synaptic currents in heterosynapses by increasing the duration of channel opening. These findings not only identify a critical role of Ser-1459 phosphorylation in regulating the function of NMDARs, but they also explain how the S1459G variant dysregulates NMDAR function.
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Affiliation(s)
- Xuan Ling Hilary Yong
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Lingrui Zhang
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liming Yang
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiumin Chen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jing Zhi Anson Tan
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiaojun Yu
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mintu Chandra
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Emma Livingstone
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Marta M Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joseph W Lynch
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Angelo Keramidas
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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4
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UPF2 leads to degradation of dendritically targeted mRNAs to regulate synaptic plasticity and cognitive function. Mol Psychiatry 2020; 25:3360-3379. [PMID: 31636381 PMCID: PMC7566522 DOI: 10.1038/s41380-019-0547-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 12/21/2022]
Abstract
Synaptic plasticity requires a tight control of mRNA levels in dendrites. RNA translation and degradation pathways have been recently linked to neurodevelopmental and neuropsychiatric diseases, suggesting a role for RNA regulation in synaptic plasticity and cognition. While the local translation of specific mRNAs has been implicated in synaptic plasticity, the tightly controlled mechanisms that regulate local quantity of specific mRNAs remain poorly understood. Despite being the only RNA regulatory pathway that is associated with multiple mental illnesses, the nonsense-mediated mRNA decay (NMD) pathway presents an unexplored regulatory mechanism for synaptic function and plasticity. Here, we show that neuron-specific disruption of UPF2, an NMD component, in adulthood attenuates learning, memory, spine density, synaptic plasticity (L-LTP), and potentiates perseverative/repetitive behavior in mice. We report that the NMD pathway operates within dendrites to regulate Glutamate Receptor 1 (GLUR1) surface levels. Specifically, UPF2 modulates the internalization of GLUR1 and promotes its local synthesis in dendrites. We identified neuronal Prkag3 mRNA as a mechanistic substrate for NMD that contributes to the UPF2-mediated regulation of GLUR1 by limiting total GLUR1 levels. These data establish that UPF2 regulates synaptic plasticity, cognition, and local protein synthesis in dendrites, providing fundamental insight into the neuron-specific function of NMD within the brain.
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5
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Mansur F, Alarcon JM, Stackpole EE, Wang R, Richter JD. Noncanonical cytoplasmic poly(A) polymerases regulate RNA levels, alternative RNA processing, and synaptic plasticity but not hippocampal-dependent behaviours. RNA Biol 2020; 18:962-971. [PMID: 32954964 DOI: 10.1080/15476286.2020.1824061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Noncanonical poly(A) polymerases are frequently tethered to mRNA 3' untranslated regions and regulate poly(A) tail length and resulting translation. In the brain, one such poly(A) polymerase is Gld2, which is anchored to mRNA by the RNA-binding protein CPEB1 to control local translation at postsynaptic regions. Depletion of CPEB1 or Gld2 from the mouse hippocampus results in a deficit in long-term potentiation (LTP), but only depletion of CPEB1 alters animal behaviour. To test whether a related enzyme, Gld4, compensates for the lack of Gld2, we separately or simultaneously depleted both proteins from hippocampal area CA1 and again found little change in animal behaviour, but observed a deficit in LTP as well as an increase in long-term depression (LTD), two forms of protein synthesis-dependent synaptic plasticity. RNA-seq data from Gld2, Gld4, and Gld2/Gld4-depleted hippocampus show widespread changes in steady state RNA levels, alternative splicing, and alternative poly(A) site selection. Many of the RNAs subject to these alterations encode proteins that mediate synaptic function, suggesting a molecular foundation for impaired synaptic plasticity.
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Affiliation(s)
- Fernanda Mansur
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Juan Marcos Alarcon
- Department of Pathology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA
| | - Emily E Stackpole
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ruijia Wang
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Joel D Richter
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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6
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Liudkovska V, Dziembowski A. Functions and mechanisms of RNA tailing by metazoan terminal nucleotidyltransferases. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1622. [PMID: 33145994 PMCID: PMC7988573 DOI: 10.1002/wrna.1622] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/28/2022]
Abstract
Termini often determine the fate of RNA molecules. In recent years, 3' ends of almost all classes of RNA species have been shown to acquire nontemplated nucleotides that are added by terminal nucleotidyltransferases (TENTs). The best-described role of 3' tailing is the bulk polyadenylation of messenger RNAs in the cell nucleus that is catalyzed by canonical poly(A) polymerases (PAPs). However, many other enzymes that add adenosines, uridines, or even more complex combinations of nucleotides have recently been described. This review focuses on metazoan TENTs, which are either noncanonical PAPs or terminal uridylyltransferases with varying processivity. These enzymes regulate RNA stability and RNA functions and are crucial in early development, gamete production, and somatic tissues. TENTs regulate gene expression at the posttranscriptional level, participate in the maturation of many transcripts, and protect cells against viral invasion and the transposition of repetitive sequences. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Processing > 3' End Processing RNA Turnover and Surveillance > Regulation of RNA Stability.
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Affiliation(s)
- Vladyslava Liudkovska
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Andrzej Dziembowski
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
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7
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A tale of non-canonical tails: gene regulation by post-transcriptional RNA tailing. Nat Rev Mol Cell Biol 2020; 21:542-556. [PMID: 32483315 DOI: 10.1038/s41580-020-0246-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2020] [Indexed: 01/06/2023]
Abstract
RNA tailing, or the addition of non-templated nucleotides to the 3' end of RNA, is the most frequent and conserved type of RNA modification. The addition of tails and their composition reflect RNA maturation stages and have important roles in determining the fate of the modified RNAs. Apart from canonical poly(A) polymerases, which add poly(A) tails to mRNAs in a transcription-coupled manner, a family of terminal nucleotidyltransferases (TENTs), including terminal uridylyltransferases (TUTs), modify RNAs post-transcriptionally to control RNA stability and activity. The human genome encodes 11 different TENTs with distinct substrate specificity, intracellular localization and tissue distribution. In this Review, we discuss recent advances in our understanding of non-canonical RNA tails, with a focus on the functions of human TENTs, which include uridylation, mixed tailing and post-transcriptional polyadenylation of mRNAs, microRNAs and other types of non-coding RNA.
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8
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Ueberham U, Arendt T. Genomic Indexing by Somatic Gene Recombination of mRNA/ncRNA - Does It Play a Role in Genomic Mosaicism, Memory Formation, and Alzheimer's Disease? Front Genet 2020; 11:370. [PMID: 32411177 PMCID: PMC7200996 DOI: 10.3389/fgene.2020.00370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022] Open
Abstract
Recent evidence indicates that genomic individuality of neurons, characterized by DNA-content variation, is a common if not universal phenomenon in the human brain that occurs naturally but can also show aberrancies that have been linked to the pathomechanism of Alzheimer’s disease and related neurodegenerative disorders. Etiologically, this genomic mosaic has been suggested to arise from defects of cell cycle regulation that may occur either during brain development or in the mature brain after terminal differentiation of neurons. Here, we aim to draw attention towards another mechanism that can give rise to genomic individuality of neurons, with far-reaching consequences. This mechanism has its origin in the transcriptome rather than in replication defects of the genome, i.e., somatic gene recombination of RNA. We continue to develop the concept that somatic gene recombination of RNA provides a physiological process that, through integration of intronless mRNA/ncRNA into the genome, allows a particular functional state at the level of the individual neuron to be indexed. By insertion of defined RNAs in a somatic recombination process, the presence of specific mRNA transcripts within a definite temporal context can be “frozen” and can serve as an index that can be recalled at any later point in time. This allows information related to a specific neuronal state of differentiation and/or activity relevant to a memory trace to be fixed. We suggest that this process is used throughout the lifetime of each neuron and might have both advantageous and deleterious consequences.
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Affiliation(s)
- Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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9
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Synaptic GluN2A-Containing NMDA Receptors: From Physiology to Pathological Synaptic Plasticity. Int J Mol Sci 2020; 21:ijms21041538. [PMID: 32102377 PMCID: PMC7073220 DOI: 10.3390/ijms21041538] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/20/2020] [Accepted: 02/21/2020] [Indexed: 12/16/2022] Open
Abstract
N-Methyl-d-Aspartate Receptors (NMDARs) are ionotropic glutamate-gated receptors. NMDARs are tetramers composed by several homologous subunits of GluN1-, GluN2-, or GluN3-type, leading to the existence in the central nervous system of a high variety of receptor subtypes with different pharmacological and signaling properties. NMDAR subunit composition is strictly regulated during development and by activity-dependent synaptic plasticity. Given the differences between GluN2 regulatory subunits of NMDAR in several functions, here we will focus on the synaptic pool of NMDARs containing the GluN2A subunit, addressing its role in both physiology and pathological synaptic plasticity as well as the contribution in these events of different types of GluN2A-interacting proteins.
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10
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Roy R, Shiina N, Wang DO. More dynamic, more quantitative, unexpectedly intricate: Advanced understanding on synaptic RNA localization in learning and memory. Neurobiol Learn Mem 2019; 168:107149. [PMID: 31881355 DOI: 10.1016/j.nlm.2019.107149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/25/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023]
Abstract
Synaptic signaling exhibits great diversity, complexity, and plasticity which necessitates maintenance and rapid modification of a local proteome. One solution neurons actively exploit to meet such demands is the strategic deposition of mRNAs encoding proteins for both basal and experience-driven activities into ribonucleoprotein complexes at the synapse. Transcripts localized in this manner can be rapidly accessed for translation in response to a diverse range of stimuli in a temporal- and spatially-restricted manner. Here we review recent findings on localized RNAs and RNA binding proteins in the context of learning and memory, as revealed by cutting-edge in-vitro and in-vivo technologies capable of yielding quantitative and dynamic information. The new technologies include proteomic and transcriptomic analyses, high-resolution multiplexed RNA imaging, single-molecule RNA tracking in living neurons, animal models and human neuron cell models. Among many recent advances in the field, RNA chemical modification has emerged as one of the new regulatory layers of gene expression at synapse that is complex and yet largely unexplored. These exciting new discoveries have enhanced our understanding of the modulation mechanisms of synaptic gene expression and their roles in cognition.
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Affiliation(s)
- Rohini Roy
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, SOKENDAI, Okazaki, Japan; Exploratory Research Center on Life and Living Systems, Okazaki, Japan.
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Liaoning, China; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan; The Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research (K-CONNEX), Kyoto University, Kyoto, Japan.
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11
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Lee JH, Kang M, Park S, Perez-Flores MC, Zhang XD, Wang W, Gratton MA, Chiamvimonvat N, Yamoah EN. The local translation of KNa in dendritic projections of auditory neurons and the roles of KNa in the transition from hidden to overt hearing loss. Aging (Albany NY) 2019; 11:11541-11564. [PMID: 31812952 PMCID: PMC6932877 DOI: 10.18632/aging.102553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023]
Abstract
Local and privileged expression of dendritic proteins allows segregation of distinct functions in a single neuron but may represent one of the underlying mechanisms for early and insidious presentation of sensory neuropathy. Tangible characteristics of early hearing loss (HL) are defined in correlation with nascent hidden hearing loss (HHL) in humans and animal models. Despite the plethora of causes of HL, only two prevailing mechanisms for HHL have been identified, and in both cases, common structural deficits are implicated in inner hair cell synapses, and demyelination of the auditory nerve (AN). We uncovered that Na+-activated K+ (KNa) mRNA and channel proteins are distinctly and locally expressed in dendritic projections of primary ANs and genetic deletion of KNa channels (Kcnt1 and Kcnt2) results in the loss of proper AN synaptic function, characterized as HHL, without structural synaptic alterations. We further demonstrate that the local functional synaptic alterations transition from HHL to increased hearing-threshold, which entails changes in global Ca2+ homeostasis, activation of caspases 3/9, impaired regulation of inositol triphosphate receptor 1 (IP3R1), and apoptosis-mediated neurodegeneration. Thus, the present study demonstrates how local synaptic dysfunction results in an apparent latent pathological phenotype (HHL) and, if undetected, can lead to overt HL. It also highlights, for the first time, that HHL can precede structural synaptic dysfunction and AN demyelination. The stepwise cellular mechanisms from HHL to canonical HL are revealed, providing a platform for intervention to prevent lasting and irreversible age-related hearing loss (ARHL).
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Affiliation(s)
- Jeong Han Lee
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Mincheol Kang
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Seojin Park
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Maria C Perez-Flores
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Xiao-Dong Zhang
- Department of Internal Medicine, Division of Cardiology, University of California Davis, Davis, CA 95616, USA
| | - Wenying Wang
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Michael Anne Gratton
- Department of Otolaryngology, Head and Neck Surgery, Washington University St. Louis, St. Louis, MO 63110, USA
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, Division of Cardiology, University of California Davis, Davis, CA 95616, USA
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
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12
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Afonso P, De Luca P, Carvalho RS, Cortes L, Pinheiro P, Oliveiros B, Almeida RD, Mele M, Duarte CB. BDNF increases synaptic NMDA receptor abundance by enhancing the local translation of Pyk2 in cultured hippocampal neurons. Sci Signal 2019; 12:12/586/eaav3577. [PMID: 31213568 DOI: 10.1126/scisignal.aav3577] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of brain-derived neurotrophic factor (BDNF) in long-term synaptic potentiation (LTP) are thought to underlie learning and memory formation and are partly mediated by local protein synthesis. Here, we investigated the mechanisms that mediate BDNF-induced alterations in the synaptic proteome that are coupled to synaptic strengthening. BDNF induced the synaptic accumulation of GluN2B-containing NMDA receptors (NMDARs) and increased the amplitude of NMDAR-mediated miniature excitatory postsynaptic currents (mEPSCs) in cultured rat hippocampal neurons by a mechanism requiring activation of the protein tyrosine kinase Pyk2 and dependent on cellular protein synthesis. Single-particle tracking using quantum dot imaging revealed that the increase in the abundance of synaptic NMDAR currents correlated with their enhanced stability in the synaptic compartment. Furthermore, BDNF increased the local synthesis of Pyk2 at the synapse, and the observed increase in Pyk2 protein abundance along dendrites of cultured hippocampal neurons was mediated by a mechanism dependent on the ribonucleoprotein hnRNP K, which bound to Pyk2 mRNA and dissociated from it upon BDNF application. Knocking down hnRNP K reduced the BDNF-induced synaptic synthesis of Pyk2 protein, whereas its overexpression enhanced it. Together, these findings indicate that hnRNP K mediates the synaptic distribution of Pyk2 synthesis, and hence the synaptic incorporation of GluN2B-containing NMDARs, induced by BDNF, which may affect LTP and synaptic plasticity.
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Affiliation(s)
- Pedro Afonso
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Pasqualino De Luca
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra (IIIUC), 3030-790 Coimbra, Portugal
| | - Rafael S Carvalho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Luísa Cortes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra (IIIUC), 3030-790 Coimbra, Portugal
| | - Paulo Pinheiro
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra (IIIUC), 3030-790 Coimbra, Portugal
| | - Barbara Oliveiros
- Laboratory of Biostatistics and Medical Informatics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ramiro D Almeida
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Health Sciences Program, Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Miranda Mele
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra (IIIUC), 3030-790 Coimbra, Portugal
| | - Carlos B Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal. .,Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
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13
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Aparisi Rey A, Karaulanov E, Sharopov S, Arab K, Schäfer A, Gierl M, Guggenhuber S, Brandes C, Pennella L, Gruhn WH, Jelinek R, Maul C, Conrad A, Kilb W, Luhmann HJ, Niehrs C, Lutz B. Gadd45α modulates aversive learning through post-transcriptional regulation of memory-related mRNAs. EMBO Rep 2019; 20:embr.201846022. [PMID: 30948457 PMCID: PMC6549022 DOI: 10.15252/embr.201846022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 02/22/2019] [Accepted: 03/07/2019] [Indexed: 01/25/2023] Open
Abstract
Learning is essential for survival and is controlled by complex molecular mechanisms including regulation of newly synthesized mRNAs that are required to modify synaptic functions. Despite the well‐known role of RNA‐binding proteins (RBPs) in mRNA functionality, their detailed regulation during memory consolidation is poorly understood. This study focuses on the brain function of the RBP Gadd45α (growth arrest and DNA damage‐inducible protein 45 alpha, encoded by the Gadd45a gene). Here, we find that hippocampal memory and long‐term potentiation are strongly impaired in Gadd45a‐deficient mice, a phenotype accompanied by reduced levels of memory‐related mRNAs. The majority of the Gadd45α‐regulated transcripts show unusually long 3′ untranslated regions (3′UTRs) that are destabilized in Gadd45a‐deficient mice via a transcription‐independent mechanism, leading to reduced levels of the corresponding proteins in synaptosomes. Moreover, Gadd45α can bind specifically to these memory‐related mRNAs. Our study reveals a new function for extended 3′UTRs in memory consolidation and identifies Gadd45α as a novel regulator of mRNA stability.
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Affiliation(s)
- Alejandro Aparisi Rey
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Salim Sharopov
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | | | | | - Stephan Guggenhuber
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Caroline Brandes
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Luigi Pennella
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Ruth Jelinek
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christina Maul
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Andrea Conrad
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christof Niehrs
- Institute of Molecular Biology, Mainz, Germany .,Division of Molecular Embryology, DKFZ-ZMBH Alliance, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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14
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Warkocki Z, Liudkovska V, Gewartowska O, Mroczek S, Dziembowski A. Terminal nucleotidyl transferases (TENTs) in mammalian RNA metabolism. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2018.0162. [PMID: 30397099 PMCID: PMC6232586 DOI: 10.1098/rstb.2018.0162] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2018] [Indexed: 12/15/2022] Open
Abstract
In eukaryotes, almost all RNA species are processed at their 3′ ends and most mRNAs are polyadenylated in the nucleus by canonical poly(A) polymerases. In recent years, several terminal nucleotidyl transferases (TENTs) including non-canonical poly(A) polymerases (ncPAPs) and terminal uridyl transferases (TUTases) have been discovered. In contrast to canonical polymerases, TENTs' functions are more diverse; some, especially TUTases, induce RNA decay while others, such as cytoplasmic ncPAPs, activate translationally dormant deadenylated mRNAs. The mammalian genome encodes 11 different TENTs. This review summarizes the current knowledge about the functions and mechanisms of action of these enzymes. This article is part of the theme issue ‘5′ and 3′ modifications controlling RNA degradation’.
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Affiliation(s)
- Zbigniew Warkocki
- Department of RNA Metabolism, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznan, Poland
| | - Vladyslava Liudkovska
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Olga Gewartowska
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Seweryn Mroczek
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland.,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Andrzej Dziembowski
- Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland .,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland
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15
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Ravanidis S, Kattan FG, Doxakis E. Unraveling the Pathways to Neuronal Homeostasis and Disease: Mechanistic Insights into the Role of RNA-Binding Proteins and Associated Factors. Int J Mol Sci 2018; 19:ijms19082280. [PMID: 30081499 PMCID: PMC6121432 DOI: 10.3390/ijms19082280] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/13/2022] Open
Abstract
The timing, dosage and location of gene expression are fundamental determinants of brain architectural complexity. In neurons, this is, primarily, achieved by specific sets of trans-acting RNA-binding proteins (RBPs) and their associated factors that bind to specific cis elements throughout the RNA sequence to regulate splicing, polyadenylation, stability, transport and localized translation at both axons and dendrites. Not surprisingly, misregulation of RBP expression or disruption of its function due to mutations or sequestration into nuclear or cytoplasmic inclusions have been linked to the pathogenesis of several neuropsychiatric and neurodegenerative disorders such as fragile-X syndrome, autism spectrum disorders, spinal muscular atrophy, amyotrophic lateral sclerosis and frontotemporal dementia. This review discusses the roles of Pumilio, Staufen, IGF2BP, FMRP, Sam68, CPEB, NOVA, ELAVL, SMN, TDP43, FUS, TAF15, and TIA1/TIAR in RNA metabolism by analyzing their specific molecular and cellular function, the neurological symptoms associated with their perturbation, and their axodendritic transport/localization along with their target mRNAs as part of larger macromolecular complexes termed ribonucleoprotein (RNP) granules.
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Affiliation(s)
- Stylianos Ravanidis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Fedon-Giasin Kattan
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
| | - Epaminondas Doxakis
- Basic Sciences Division I, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece.
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16
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Tushev G, Glock C, Heumüller M, Biever A, Jovanovic M, Schuman EM. Alternative 3' UTRs Modify the Localization, Regulatory Potential, Stability, and Plasticity of mRNAs in Neuronal Compartments. Neuron 2018; 98:495-511.e6. [PMID: 29656876 DOI: 10.1016/j.neuron.2018.03.030] [Citation(s) in RCA: 224] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 01/20/2018] [Accepted: 03/16/2018] [Indexed: 02/07/2023]
Abstract
Neurons localize mRNAs near synapses where their translation can be regulated by synaptic demand and activity. Differences in the 3' UTRs of mRNAs can change their localization, stability, and translational regulation. Using 3' end RNA sequencing of microdissected rat brain slices, we discovered a huge diversity in mRNA 3' UTRs, with many transcripts showing enrichment for a particular 3' UTR isoform in either somata or the neuropil. The 3' UTR isoforms of localized transcripts are significantly longer than the 3' UTRs of non-localized transcripts and often code for proteins associated with axons, dendrites, and synapses. Surprisingly, long 3' UTRs add not only new, but also duplicate regulatory elements. The neuropil-enriched 3' UTR isoforms have significantly longer half-lives than somata-enriched isoforms. Finally, the 3' UTR isoforms can be significantly altered by enhanced activity. Most of the 3' UTR plasticity is transcription dependent, but intriguing examples of changes that are consistent with altered stability, trafficking between compartments, or local "remodeling" remain.
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Affiliation(s)
- Georgi Tushev
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Caspar Glock
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | | | - Anne Biever
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Marko Jovanovic
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany.
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17
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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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18
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NMDA Receptor Subunits Change after Synaptic Plasticity Induction and Learning and Memory Acquisition. Neural Plast 2018; 2018:5093048. [PMID: 29706992 PMCID: PMC5863338 DOI: 10.1155/2018/5093048] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/17/2017] [Accepted: 01/04/2018] [Indexed: 01/16/2023] Open
Abstract
NMDA ionotropic glutamate receptors (NMDARs) are crucial in activity-dependent synaptic changes and in learning and memory. NMDARs are composed of two GluN1 essential subunits and two regulatory subunits which define their pharmacological and physiological profile. In CNS structures involved in cognitive functions as the hippocampus and prefrontal cortex, GluN2A and GluN2B are major regulatory subunits; their expression is dynamic and tightly regulated, but little is known about specific changes after plasticity induction or memory acquisition. Data strongly suggest that following appropriate stimulation, there is a rapid increase in surface GluN2A-NMDAR at the postsynapses, attributed to lateral receptor mobilization from adjacent locations. Whenever synaptic plasticity is induced or memory is consolidated, more GluN2A-NMDARs are assembled likely using GluN2A from a local translation and GluN1 from local ER. Later on, NMDARs are mobilized from other pools, and there are de novo syntheses at the neuron soma. Changes in GluN1 or NMDAR levels induced by synaptic plasticity and by spatial memory formation seem to occur in different waves of NMDAR transport/expression/degradation, with a net increase at the postsynaptic side and a rise in expression at both the spine and neuronal soma. This review aims to put together that information and the proposed hypotheses.
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19
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Swanger SA, Vance KM, Acker TM, Zimmerman SS, DiRaddo JO, Myers SJ, Bundgaard C, Mosley CA, Summer SL, Menaldino DS, Jensen HS, Liotta DC, Traynelis SF. A Novel Negative Allosteric Modulator Selective for GluN2C/2D-Containing NMDA Receptors Inhibits Synaptic Transmission in Hippocampal Interneurons. ACS Chem Neurosci 2018; 9:306-319. [PMID: 29043770 PMCID: PMC5924706 DOI: 10.1021/acschemneuro.7b00329] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
N-Methyl-d-aspartate receptors (NMDARs) are ionotropic glutamate receptors that mediate excitatory synaptic transmission and have been implicated in numerous neurological disorders. NMDARs typically comprise two GluN1 and two GluN2 subunits. The four GluN2 subtypes (GluN2A-GluN2D) have distinct functional properties and gene expression patterns, which contribute to diverse functional roles for NMDARs in the brain. Here, we present a series of GluN2C/2D-selective negative allosteric modulators built around a N-aryl benzamide (NAB) core. The prototypical compound, NAB-14, is >800-fold selective for recombinant GluN2C/GluN2D over GluN2A/GluN2B in Xenopus oocytes and has an IC50 value of 580 nM at recombinant GluN2D-containing receptors expressed in mammalian cells. NAB-14 inhibits triheteromeric (GluN1/GluN2A/GluN2C) NMDARs with modestly reduced potency and efficacy compared to diheteromeric (GluN1/GluN2C/GluN2C) receptors. Site-directed mutagenesis suggests that structural determinants for NAB-14 inhibition reside in the GluN2D M1 transmembrane helix. NAB-14 inhibits GluN2D-mediated synaptic currents in rat subthalamic neurons and mouse hippocampal interneurons, but has no effect on synaptic transmission in hippocampal pyramidal neurons, which do not express GluN2C or GluN2D. This series possesses some druglike physical properties and modest brain permeability in rat and mouse. Altogether, this work identifies a new series of negative allosteric modulators that are valuable tools for studying GluN2C- and GluN2D-containing NMDAR function in brain circuits, and suggests that the series has the potential to be developed into therapies for selectively modulating brain circuits involving the GluN2C and GluN2D subunits.
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Affiliation(s)
- Sharon A. Swanger
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
| | - Katie M. Vance
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
| | | | | | - John O. DiRaddo
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
- Department of Chemistry, Emory University, Atlanta, GA 30322
| | - Scott J. Myers
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
| | | | - Cara A. Mosley
- Department of Chemistry, Emory University, Atlanta, GA 30322
| | | | | | - Henrik S. Jensen
- H. Lundbeck A/S, Molecular Screening, Ottiliavej 9, DK-2500 Valby, Denmark
| | | | - Stephen F. Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
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20
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Pacheco A, Aguayo FI, Aliaga E, Muñoz M, García-Rojo G, Olave FA, Parra-Fiedler NA, García-Pérez A, Tejos-Bravo M, Rojas PS, Parra CS, Fiedler JL. Chronic Stress Triggers Expression of Immediate Early Genes and Differentially Affects the Expression of AMPA and NMDA Subunits in Dorsal and Ventral Hippocampus of Rats. Front Mol Neurosci 2017; 10:244. [PMID: 28848384 PMCID: PMC5554379 DOI: 10.3389/fnmol.2017.00244] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 07/20/2017] [Indexed: 12/12/2022] Open
Abstract
Previous studies in rats have demonstrated that chronic restraint stress triggers anhedonia, depressive-like behaviors, anxiety and a reduction in dendritic spine density in hippocampal neurons. In this study, we compared the effect of repeated stress on the expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor subunits in dorsal and ventral hippocampus (VH). Adult male Sprague-Dawley rats were randomly divided into control and stressed groups, and were daily restrained in their motion (2.5 h/day) during 14 days. We found that chronic stress promotes an increase in c-Fos mRNA levels in both hippocampal areas, although it was observed a reduction in the immunoreactivity at pyramidal cell layer. Furthermore, Arc mRNAs levels were increased in both dorsal and VH, accompanied by an increase in Arc immunoreactivity in dendritic hippocampal layers. Furthermore, stress triggered a reduction in PSD-95 and NR1 protein levels in whole extract of dorsal and VH. Moreover, a reduction in NR2A/NR2B ratio was observed only in dorsal pole. In synaptosomal fractions, we detected a rise in NR1 in dorsal hippocampus (DH). By indirect immunofluorescence we found that NR1 subunits rise, especially in neuropil areas of dorsal, but not VH. In relation to AMPA receptor (AMPAR) subunits, chronic stress did not trigger any change, either in dorsal or ventral hippocampal areas. These data suggest that DH is more sensitive than VH to chronic stress exposure, mainly altering the expression of NMDA receptor (NMDAR) subunits, and probably favors changes in the configuration of this receptor that may influence the function of this area.
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Affiliation(s)
- Anibal Pacheco
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Felipe I Aguayo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Esteban Aliaga
- Department of Kinesiology, Faculty of Health Sciences, Universidad Católica del MauleTalca, Chile
| | - Mauricio Muñoz
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Gonzalo García-Rojo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Felipe A Olave
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Nicolas A Parra-Fiedler
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Alexandra García-Pérez
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Macarena Tejos-Bravo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Paulina S Rojas
- Faculty of Medicine, School of Pharmacy, Universidad Andres BelloSantiago, Chile
| | - Claudio S Parra
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
| | - Jenny L Fiedler
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de ChileIndependencia, Chile
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21
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Fragile X Mental Retardation Protein Is Required to Maintain Visual Conditioning-Induced Behavioral Plasticity by Limiting Local Protein Synthesis. J Neurosci 2017; 36:7325-39. [PMID: 27383604 DOI: 10.1523/jneurosci.4282-15.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 05/28/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Fragile X mental retardation protein (FMRP) is thought to regulate neuronal plasticity by limiting dendritic protein synthesis, but direct demonstration of a requirement for FMRP control of local protein synthesis during behavioral plasticity is lacking. Here we tested whether FMRP knockdown in Xenopus optic tectum affects local protein synthesis in vivo and whether FMRP knockdown affects protein synthesis-dependent visual avoidance behavioral plasticity. We tagged newly synthesized proteins by incorporation of the noncanonical amino acid azidohomoalanine and visualized them with fluorescent noncanonical amino acid tagging (FUNCAT). Visual conditioning and FMRP knockdown produce similar increases in FUNCAT in tectal neuropil. Induction of visual conditioning-dependent behavioral plasticity occurs normally in FMRP knockdown animals, but plasticity degrades over 24 h. These results indicate that FMRP affects visual conditioning-induced local protein synthesis and is required to maintain the visual conditioning-induced behavioral plasticity. SIGNIFICANCE STATEMENT Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Exaggerated dendritic protein synthesis resulting from loss of fragile X mental retardation protein (FMRP) is thought to underlie cognitive deficits in FXS, but no direct evidence has demonstrated that FMRP-regulated dendritic protein synthesis affects behavioral plasticity in intact animals. Xenopus tadpoles exhibit a visual avoidance behavior that improves with visual conditioning in a protein synthesis-dependent manner. We showed that FMRP knockdown and visual conditioning dramatically increase protein synthesis in neuronal processes. Furthermore, induction of visual conditioning-dependent behavioral plasticity occurs normally after FMRP knockdown, but performance rapidly deteriorated in the absence of FMRP. These studies show that FMRP negatively regulates local protein synthesis and is required to maintain visual conditioning-induced behavioral plasticity in vivo.
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22
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Prieto GA, Cotman CW. Cytokines and cytokine networks target neurons to modulate long-term potentiation. Cytokine Growth Factor Rev 2017; 34:27-33. [PMID: 28377062 PMCID: PMC5491344 DOI: 10.1016/j.cytogfr.2017.03.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/28/2017] [Indexed: 12/20/2022]
Abstract
Cytokines play crucial roles in the communication between brain cells including neurons and glia, as well as in the brain-periphery interactions. In the brain, cytokines modulate long-term potentiation (LTP), a cellular correlate of memory. Whether cytokines regulate LTP by direct effects on neurons or by indirect mechanisms mediated by non-neuronal cells is poorly understood. Elucidating neuron-specific effects of cytokines has been challenging because most brain cells express cytokine receptors. Moreover, cytokines commonly increase the expression of multiple cytokines in their target cells, thus increasing the complexity of brain cytokine networks even after single-cytokine challenges. Here, we review evidence on both direct and indirect-mediated modulation of LTP by cytokines. We also describe novel approaches based on neuron- and synaptosome-enriched systems to identify cytokines able to directly modulate LTP, by targeting neurons and synapses. These approaches can test multiple samples in parallel, thus allowing the study of multiple cytokines simultaneously. Hence, a cytokine networks perspective coupled with neuron-specific analysis may contribute to delineation of maps of the modulation of LTP by cytokines.
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Affiliation(s)
- G Aleph Prieto
- Institute for Memory Impairments and Neurological Disorders, University of California-Irvine, Irvine, CA 92697, USA.
| | - Carl W Cotman
- Institute for Memory Impairments and Neurological Disorders, University of California-Irvine, Irvine, CA 92697, USA
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23
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Chen W, Shieh C, Swanger SA, Tankovic A, Au M, McGuire M, Tagliati M, Graham JM, Madan-Khetarpal S, Traynelis SF, Yuan H, Pierson TM. GRIN1 mutation associated with intellectual disability alters NMDA receptor trafficking and function. J Hum Genet 2017; 62:589-597. [PMID: 28228639 DOI: 10.1038/jhg.2017.19] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/21/2016] [Accepted: 01/09/2017] [Indexed: 02/03/2023]
Abstract
N-methyl-d-aspartate receptors (NMDARs) play important roles in brain development and neurological disease. We report two individuals with similar dominant de novo GRIN1 mutations (c.1858 G>A and c.1858 G>C; both p.G620R). Both individuals presented at birth with developmental delay and hypotonia associated with behavioral abnormalities and stereotypical movements. Recombinant NMDARs containing the mutant GluN1-G620R together with either GluN2A or GluN2B were evaluated for changes in their trafficking to the plasma membrane and their electrophysiological properties. GluN1-G620R/GluN2A complexes showed a mild reduction in trafficking, a ~2-fold decrease in glutamate and glycine potency, a strong decrease in sensitivity to Mg2+ block, and a significant reduction of current responses to a maximal effective concentration of agonists. GluN1-G620R/GluN2B complexes showed significantly reduced delivery of protein to the cell surface associated with similarly altered electrophysiology. These results indicate these individuals may have suffered neurodevelopmental deficits as a result of the decreased presence of GluN1-G620R/GluN2B complexes on the neuronal surface during embryonic brain development and reduced current responses of GluN1-G620R-containing NMDARs after birth. These cases emphasize the importance of comprehensive functional characterization of de novo mutations and illustrates how a combination of several distinct features of NMDAR expression, trafficking and function can be present and influence phenotype.
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Affiliation(s)
- Wenjuan Chen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Christine Shieh
- David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, USA
| | - Sharon A Swanger
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Anel Tankovic
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Margaret Au
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Marianne McGuire
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Michele Tagliati
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - John M Graham
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, USA
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, USA
| | - Tyler Mark Pierson
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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24
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Niu Y, Dai Z, Liu W, Zhang C, Yang Y, Guo Z, Li X, Xu C, Huang X, Wang Y, Shi YS, Liu JJ. Ablation of SNX6 leads to defects in synaptic function of CA1 pyramidal neurons and spatial memory. eLife 2017; 6. [PMID: 28134614 PMCID: PMC5323044 DOI: 10.7554/elife.20991] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 01/28/2017] [Indexed: 11/14/2022] Open
Abstract
SNX6 is a ubiquitously expressed PX-BAR protein that plays important roles in retromer-mediated retrograde vesicular transport from endosomes. Here we report that CNS-specific Snx6 knockout mice exhibit deficits in spatial learning and memory, accompanied with loss of spines from distal dendrites of hippocampal CA1 pyramidal cells. SNX6 interacts with Homer1b/c, a postsynaptic scaffold protein crucial for the synaptic distribution of other postsynaptic density (PSD) proteins and structural integrity of dendritic spines. We show that SNX6 functions independently of retromer to regulate distribution of Homer1b/c in the dendritic shaft. We also find that Homer1b/c translocates from shaft to spines by protein diffusion, which does not require SNX6. Ablation of SNX6 causes reduced distribution of Homer1b/c in distal dendrites, decrease in surface levels of AMPAR and impaired AMPAR-mediated synaptic transmission. These findings reveal a physiological role of SNX6 in CNS excitatory neurons. DOI:http://dx.doi.org/10.7554/eLife.20991.001 Neurons are the building blocks of the nervous system. These cells generally consist of a round portion called the cell body and a long cable-like axon. The cell body bears numerous branches called dendrites, which are in turn covered in spines. Neurons communicate with one another at junctions – or synapses – that typically form between the end of the axon of one cell and a dendritic spine on another. Specialized proteins stabilize the dendritic spines and enable the cells to exchange messages across the synapse. However, it is the cell body – rather than the dendrites – that produces most of these proteins. Structures called molecular motors transport proteins to their destinations within the cell along fixed tracks, similar to how a freight train carries cargo over the rail network. One of the key molecular motors within neurons is called dynein‒dynactin. This in turn interacts with other proteins called adaptors, enabling it to transport specific types of cargo. Niu, Dai, Liu et al. have now examined the role of SNX6, an adaptor protein for the dynein‒dynactin motor. Mice that have been genetically modified to lack SNX6 in their brains have fewer spines on their dendrites compared with normal mice. This was particularly true for dendrites that contain AMPAR, a protein that receives signals sent across synapses. Niu, Dai, Liu et al. showed that SNX6 interacts with another protein called Homer1b/c and is responsible for distributing this protein in dendrites far from the cell body. The Homer1b/c protein helps to stabilize dendritic spines and to regulate the number of AMPAR proteins within them. Mice that lack SNX6 therefore have less Homer1b/c in the dendrites furthest from the cell body, and fewer spines on these dendrites too. These mice also have fewer AMPAR proteins at their synapses than control mice. Mice that lack SNX6 show impaired learning and memory compared to control mice. This is consistent with the fact that changes in the strength of synapses that possess AMPAR proteins are thought to underlie learning and memory. Additional experiments are required to explore these relationships further, and to determine whether SNX6 helps to localize any other proteins that also contribute to changes in the strength of synapses. DOI:http://dx.doi.org/10.7554/eLife.20991.002
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Affiliation(s)
- Yang Niu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Zhonghua Dai
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Wenxue Liu
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China.,MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Model Animal Research Center, Nanjing University, Nanjing, China
| | - Cheng Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yanrui Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Zhenzhen Guo
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyu Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Chenchang Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yun S Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China.,MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Model Animal Research Center, Nanjing University, Nanjing, China
| | - Jia-Jia Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
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25
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Molecular Mechanism of Disease-Associated Mutations in the Pre-M1 Helix of NMDA Receptors and Potential Rescue Pharmacology. PLoS Genet 2017; 13:e1006536. [PMID: 28095420 PMCID: PMC5240934 DOI: 10.1371/journal.pgen.1006536] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/13/2016] [Indexed: 12/31/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs), ligand-gated ionotropic glutamate receptors, play key roles in normal brain development and various neurological disorders. Here we use standing variation data from the human population to assess which protein domains within NMDAR GluN1, GluN2A and GluN2B subunits show the strongest signal for being depleted of missense variants. We find that this includes the GluN2 pre-M1 helix and linker between the agonist-binding domain (ABD) and first transmembrane domain (M1). We then evaluate the functional changes of multiple missense mutations in the NMDAR pre-M1 helix found in children with epilepsy and developmental delay. We find mutant GluN1/GluN2A receptors exhibit prolonged glutamate response time course for channels containing 1 or 2 GluN2A-P552R subunits, and a slow rise time only for receptors with 2 mutant subunits, suggesting rearrangement of one GluN2A pre-M1 helix is sufficient for rapid activation. GluN2A-P552R and analogous mutations in other GluN subunits increased the agonist potency and slowed response time course, suggesting a functionally conserved role for this residue. Although there is no detectable change in surface expression or open probability for GluN2A-P552R, the prolonged response time course for receptors that contained GluN2A-P552R increased charge transfer for synaptic-like activation, which should promote excitotoxic damage. Transfection of cultured neurons with GluN2A-P552R prolonged EPSPs, and triggered pronounced dendritic swelling in addition to excitotoxicity, which were both attenuated by memantine. These data implicate the pre-M1 region in gating, provide insight into how different subunits contribute to gating, and suggest that mutations in the pre-M1 helix can compromise neuronal health. Evaluation of FDA-approved NMDAR inhibitors on the mutant NMDAR-mediated current response and neuronal damage provides a potential clinical path to treat individuals harboring similar mutations in NMDARs.
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26
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Cercato MC, Vázquez CA, Kornisiuk E, Aguirre AI, Colettis N, Snitcofsky M, Jerusalinsky DA, Baez MV. GluN1 and GluN2A NMDA Receptor Subunits Increase in the Hippocampus during Memory Consolidation in the Rat. Front Behav Neurosci 2017; 10:242. [PMID: 28133447 PMCID: PMC5233710 DOI: 10.3389/fnbeh.2016.00242] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/12/2016] [Indexed: 01/14/2023] Open
Abstract
It is widely accepted that NMDA receptors (NMDAR) are required for learning and memory formation, and for synaptic plasticity induction. We have previously shown that hippocampal GluN1 and GluN2A NMDAR subunits significantly increased following habituation of rats to an open field (OF), while GluN2B remained unchanged. Similar results were obtained after CA1-long-term potentiation (LTP) induction in rat hippocampal slices. Other studies have also shown NMDAR up regulation at earlier and later time points after LTP induction or learning acquisition. In this work, we have studied NMDAR subunits levels in the hippocampus and prefrontal cortex (PFC) after OF habituation and after object recognition (OR), to find out whether rising of NMDAR subunits is a general and structure-specific feature during memory formation. In 1, 2 and 3 month old rats there was an increase in hippocampal GluN1 and GluN2A, but not in GluN2B levels 70 min after OF habituation. This rise overlaps with early phase of memory consolidation, suggesting a putative relationship between them. The increases fell down to control levels 90 min after training. Similar results were obtained in the hippocampus of adult rats 70 min after OR training, without changes in PFC. Following OF test or OR discrimination phase, NMDAR subunits remained unchanged. Hence, rising of hippocampal GluN1 and GluN2A appears to be a general feature after novel “spatial/discrimination” memory acquisition. To start investigating the dynamics and possible mechanisms of these changes, we have studied hippocampal neuron cultures stimulated by KCl to induce plasticity. GluN1 and GluN2A increased both in dendrites and neuronal bodies, reaching a maximum 75 min later and returning to control levels at 90 min. Translation and/or transcription and mobilization differentially contribute to this rise in subunits in bodies and dendrites. Our results showed that the NMDAR subunits increase follows a similar time course both in vitro and in vivo. These changes happen in the hippocampus where a spatial representation of the environment is being formed making possible short term and long term memories (STM and LTM); appear to be structure-specific; are preserved along life; and could be related to synaptic tagging and/or to memory consolidation of new spatial/discrimination information.
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Affiliation(s)
- Magali C Cercato
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Cecilia A Vázquez
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Edgar Kornisiuk
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Alejandra I Aguirre
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Natalia Colettis
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Marina Snitcofsky
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICET Buenos Aires, Argentina
| | - Diana A Jerusalinsky
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICETBuenos Aires, Argentina; Ciclo Básico Común-Universidad de Buenos AiresBuenos Aires, Argentina
| | - María V Baez
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biología Celular y Neurociencia, Universidad de Buenos Aires (UBA)-CONICETBuenos Aires, Argentina; 1UA de Biología Celular, Histología, Embriología y Genética, Departamento de Histología, Facultad de Medicina, Universidad de Buenos AiresBuenos Aires, Argentina
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27
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Swanger SA, Chen W, Wells G, Burger PB, Tankovic A, Bhattacharya S, Strong KL, Hu C, Kusumoto H, Zhang J, Adams DR, Millichap JJ, Petrovski S, Traynelis SF, Yuan H. Mechanistic Insight into NMDA Receptor Dysregulation by Rare Variants in the GluN2A and GluN2B Agonist Binding Domains. Am J Hum Genet 2016; 99:1261-1280. [PMID: 27839871 PMCID: PMC5142120 DOI: 10.1016/j.ajhg.2016.10.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 10/03/2016] [Indexed: 12/30/2022] Open
Abstract
Epilepsy and intellectual disability are associated with rare variants in the GluN2A and GluN2B (encoded by GRIN2A and GRIN2B) subunits of the N-methyl-D-aspartate receptor (NMDAR), a ligand-gated ion channel with essential roles in brain development and function. By assessing genetic variation across GluN2 domains, we determined that the agonist binding domain, transmembrane domain, and the linker regions between these domains were particularly intolerant to functional variation. Notably, the agonist binding domain of GluN2B exhibited significantly more variation intolerance than that of GluN2A. To understand the ramifications of missense variation in the agonist binding domain, we investigated the mechanisms by which 25 rare variants in the GluN2A and GluN2B agonist binding domains dysregulated NMDAR activity. When introduced into recombinant human NMDARs, these rare variants identified in individuals with neurologic disease had complex, and sometimes opposing, consequences on agonist binding, channel gating, receptor biogenesis, and forward trafficking. Our approach combined quantitative assessments of these effects to estimate the overall impact on synaptic and non-synaptic NMDAR function. Interestingly, similar neurologic diseases were associated with both gain- and loss-of-function variants in the same gene. Most rare variants in GluN2A were associated with epilepsy, whereas GluN2B variants were associated with intellectual disability with or without seizures. Finally, discerning the mechanisms underlying NMDAR dysregulation by these rare variants allowed investigations of pharmacologic strategies to correct NMDAR function.
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Affiliation(s)
- Sharon A Swanger
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Wenjuan Chen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gordon Wells
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Pieter B Burger
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Anel Tankovic
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | - Katie L Strong
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Chun Hu
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hirofumi Kusumoto
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jing Zhang
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David R Adams
- Undiagnosed Diseases Network, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - John J Millichap
- Departments of Pediatrics and Neurology, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Slavé Petrovski
- Department of Medicine, The University of Melbourne, Austin Health and Royal Melbourne Hospital, Melbourne, VIC 3050, Australia
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA.
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28
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Mansur F, Ivshina M, Gu W, Schaevitz L, Stackpole E, Gujja S, Edwards YJK, Richter JD. Gld2-catalyzed 3' monoadenylation of miRNAs in the hippocampus has no detectable effect on their stability or on animal behavior. RNA (NEW YORK, N.Y.) 2016; 22:1492-9. [PMID: 27495319 PMCID: PMC5029448 DOI: 10.1261/rna.056937.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/30/2016] [Indexed: 05/20/2023]
Abstract
Gld2, a noncanonical cytoplasmic poly(A) polymerase, interacts with the RNA binding protein CPEB1 to mediate polyadenylation-induced translation in dendrites of cultured hippocampal neurons. Depletion of Gld2 from the hippocampus leads to a deficit in long-term potentiation evoked by theta burst stimulation. At least in mouse liver and human primary fibroblasts, Gld2 also 3' monoadenylates and thereby stabilizes specific miRNAs, which enhance mRNA translational silencing and eventual destruction. These results suggest that Gld2 would be likely to monoadenylate and stabilize miRNAs in the hippocampus, which would produce measurable changes in animal behavior. We now report that using Gld2 knockout mice, there are detectable alterations in specific miRNA monoadenylation in the hippocampus when compared to wild type, but that these modifications produce no detectable effect on miRNA stability. Moreover, we surprisingly find no overt change in animal behavior when comparing Gld2 knockout to wild-type mice. These data indicate that miRNA monoadenylation-mediated stability is cell type-specific and that monoadenylation has no measurable effect on higher cognitive function.
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Affiliation(s)
- Fernanda Mansur
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Maria Ivshina
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Weifeng Gu
- Department of Cell Biology and Neuroscience, University of California at Riverside, Riverside, California 92521, USA
| | - Laura Schaevitz
- Animal Research and Development, Mousera, San Mateo, California 94402, USA
| | - Emily Stackpole
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Sharvari Gujja
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Yvonne J K Edwards
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Joel D Richter
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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29
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Danka Mohammed CP, Rhee H, Phee B, Kim K, Kim H, Lee H, Park JH, Jung JH, Kim JY, Kim H, Park SK, Nam HG, Kim K. miR-204 downregulates EphB2 in aging mouse hippocampal neurons. Aging Cell 2016; 15:380-8. [PMID: 26799631 PMCID: PMC4783348 DOI: 10.1111/acel.12444] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2015] [Indexed: 11/28/2022] Open
Abstract
Hippocampal synaptic function and plasticity deteriorate with age, often resulting in learning and memory deficits. As MicroRNAs (miRNAs) are important regulators of neuronal protein expression, we examined whether miRNAs may contribute to this age‐associated decline in hippocampal function. We first compared the small RNA transcriptome of hippocampal tissues from young and old mice. Among 269 hippocampal miRNAs, 80 were differentially expressed (≥ twofold) among the age groups. We focused on 36 miRNAs upregulated in the old mice compared with those in the young mice. The potential targets of these 36 miRNAs included 11 critical Eph/Ephrin synaptic signaling components. The expression levels of several genes in the Eph/Ephrin pathway, including EphB2, were significantly downregulated in the aged hippocampus. EphB2 is a known regulator of synaptic plasticity in hippocampal neurons, in part by regulating the surface expression of the NMDA receptor NR1 subunit. We found that EphB2 is a direct target of miR‐204 among miRNAs that were upregulated with age. The transfection of primary hippocampal neurons with a miR‐204 mimic suppressed both EphB2 mRNA and protein expression and reduced the surface expression of NR1. Transfection of miR‐204 also decreased the total expression of NR1. miR‐204 induces senescence‐like phenotype in fully matured neurons as evidenced by an increase in p16‐positive cells. We suggest that aging is accompanied by the upregulation of miR‐204 in the hippocampus, which downregulates EphB2 and results in reduced surface and total NR1 expression. This mechanism may contribute to age‐associated decline in hippocampal synaptic plasticity and the related cognitive functions.
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Affiliation(s)
- Chand Parvez Danka Mohammed
- Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 711‐873 Korea
- Department of New Biology DGIST Daegu 711‐873 Korea
- Department of Life Sciences POSTECH Pohang 790‐784 Korea
| | | | - Bong‐Kwan Phee
- Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 711‐873 Korea
| | - Kunhyung Kim
- Department of New Biology DGIST Daegu 711‐873 Korea
| | - Hee‐Jin Kim
- Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 711‐873 Korea
| | - Hyehyeon Lee
- Department of New Biology DGIST Daegu 711‐873 Korea
| | | | | | - Jeong Yeon Kim
- Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 711‐873 Korea
| | - Hyoung‐Chin Kim
- Korea Research Institute of Bioscience and Biotechnology Ochang 363‐883 Korea
| | - Sang Ki Park
- Department of Life Sciences POSTECH Pohang 790‐784 Korea
| | - Hong Gil Nam
- Center for Plant Aging Research Institute for Basic Science (IBS) Daegu 711‐873 Korea
- Department of New Biology DGIST Daegu 711‐873 Korea
| | - Keetae Kim
- Department of New Biology DGIST Daegu 711‐873 Korea
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30
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Hanus C, Ehlers MD. Specialization of biosynthetic membrane trafficking for neuronal form and function. Curr Opin Neurobiol 2016; 39:8-16. [PMID: 27010827 DOI: 10.1016/j.conb.2016.03.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/01/2016] [Accepted: 03/07/2016] [Indexed: 10/24/2022]
Abstract
Neuronal growth and synaptic transmission require the continuous production of adhesion molecules, neurotransmitter receptors, ion-channels, and secreted trophic factors, and thus critically relies on the secretory pathway-the series of intracellular organelles including the endoplasmic reticulum (ER) and the Golgi apparatus (GA), where membrane lipids and proteins are synthesized. Commensurate with the gigantic size of the neuronal membrane and its compartmentalization by thousands of synapses with distinct compositions and activities, the neuronal secretory pathway has evolved to both traffic synaptic components over very long distances, and locally control the composition of specified segments of dendrites. Here we review new insights into the distribution and dynamics of dendritic secretory organelles and their impact on postsynaptic compartments.
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Affiliation(s)
- Cyril Hanus
- Department of Synaptic Plasticity, Max Planck Institute for Brain Research, Frankfurt, Germany.
| | - Michael D Ehlers
- Neuroscience Research Unit, BioTherapeutics, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA.
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31
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The levels of the GluN2A NMDA receptor subunit are modified in both the neonatal and adult rat brain by an early experience involving denial of maternal contact. Neurosci Lett 2015; 612:98-103. [PMID: 26679226 DOI: 10.1016/j.neulet.2015.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/27/2015] [Accepted: 12/04/2015] [Indexed: 11/24/2022]
Abstract
The composition of the N-methyl-d-aspartate receptor receptor in GluN2A/GluN2B subunits is important in determining its characteristics and its role in plasticity, a property of the brain which is known to be critically affected by early experiences. In the present work we employed an early experience model involving either receipt (RER) or denial (DER) of the expected reward of maternal contact within the context of learning by the pups of a T-maze on postnatal days (PND) 10-13. We investigated the effects of the RER and DER early experiences on GluN1, GluN2A and GluN2B levels in the prefrontal cortex (PFC), hippocampus and amygdala of the rat. We show that on PND13 the DER animals had lower GluN2A levels in the PFC. In adulthood DER males had higher GluN2A levels in the hippocampus, both under basal conditions and after exposure to a novel environment. The early experiences did not affect the response to the novelty. After exposure to a novel environment animals of all three groups (DER, RER, Control) responded with an increase in GluN2A levels in the brain areas examined. We did not detect any effects on GluN1 or GluN2B levels. The alterations in GluN2A levels observed in the DER animals could in part be responsible for their behavioral phenotype, described previously, which includes an increased susceptibility for the expression of depressive-like behavior.
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32
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Jain S, Welshhans K. Netrin-1 induces local translation of down syndrome cell adhesion molecule in axonal growth cones. Dev Neurobiol 2015; 76:799-816. [PMID: 26518186 DOI: 10.1002/dneu.22360] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/14/2015] [Accepted: 10/28/2015] [Indexed: 01/16/2023]
Abstract
Down syndrome cell adhesion molecule (DSCAM) plays an important role in many neurodevelopmental processes such as axon guidance, dendrite arborization, and synapse formation. DSCAM is located in the Down syndrome trisomic region of human chromosome 21 and may contribute to the Down syndrome brain phenotype, which includes a reduction in the formation of long-distance connectivity. The local translation of a select group of mRNA transcripts within growth cones is necessary for the formation of appropriate neuronal connectivity. Interestingly, we have found that Dscam mRNA is localized to growth cones of mouse hippocampal neurons, and is dynamically regulated in response to the axon guidance molecule, netrin-1. Furthermore, netrin-1 stimulation results in an increase in locally translated DSCAM protein in growth cones. Deleted in colorectal cancer (DCC), a netrin-1 receptor, is required for the netrin-1-induced increase in Dscam mRNA local translation. We also find that two RNA-binding proteins-fragile X mental retardation protein (FMRP) and cytoplasmic polyadenylation element binding protein (CPEB)-colocalize with Dscam mRNA in growth cones, suggesting their regulation of Dscam mRNA localization and translation. Finally, overexpression of DSCAM in mouse cortical neurons results in a severe stunting of axon outgrowth and branching, suggesting that an increase in DSCAM protein results in a structural change having functional consequences. Taken together, these results suggest that netrin-1-induced local translation of Dscam mRNA during embryonic development may be an important mechanism to regulate axon growth and guidance in the developing nervous system. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 799-816, 2016.
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Affiliation(s)
- Shruti Jain
- Department of Biological Sciences, Kent State University, Kent, Ohio, 44242
| | - Kristy Welshhans
- Department of Biological Sciences, Kent State University, Kent, Ohio, 44242.,School of Biomedical Sciences, Kent State University, Kent, Ohio, 44242
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33
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Zhang XM, Yan XY, Zhang B, Yang Q, Ye M, Cao W, Qiang WB, Zhu LJ, Du YL, Xu XX, Wang JS, Xu F, Lu W, Qiu S, Yang W, Luo JH. Activity-induced synaptic delivery of the GluN2A-containing NMDA receptor is dependent on endoplasmic reticulum chaperone Bip and involved in fear memory. Cell Res 2015; 25:818-36. [PMID: 26088419 DOI: 10.1038/cr.2015.75] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 03/02/2015] [Accepted: 05/04/2015] [Indexed: 11/09/2022] Open
Abstract
The N-methyl-D-aspartate receptor (NMDAR) in adult forebrain is a heterotetramer mainly composed of two GluN1 subunits and two GluN2A and/or GluN2B subunits. The synaptic expression and relative numbers of GluN2A- and GluN2B-containing NMDARs play critical roles in controlling Ca(2+)-dependent signaling and synaptic plasticity. Previous studies have suggested that the synaptic trafficking of NMDAR subtypes is differentially regulated, but the precise molecular mechanism is not yet clear. In this study, we demonstrated that Bip, an endoplasmic reticulum (ER) chaperone, selectively interacted with GluN2A and mediated the neuronal activity-induced assembly and synaptic incorporation of the GluN2A-containing NMDAR from dendritic ER. Furthermore, the GluN2A-specific synaptic trafficking was effectively disrupted by peptides interrupting the interaction between Bip and GluN2A. Interestingly, fear conditioning in mice was disrupted by intraperitoneal injection of the interfering peptide before training. In summary, we have uncovered a novel mechanism for the activity-dependent supply of synaptic GluN2A-containing NMDARs, and demonstrated its relevance to memory formation.
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Affiliation(s)
- Xiao-min Zhang
- 1] Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China [2] Department of Physiology, Kunming Medical University, Kunming, Yunnan 650500, China
| | - Xun-yi Yan
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Bin Zhang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qian Yang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Mao Ye
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wei Cao
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wen-bin Qiang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Li-jun Zhu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yong-lan Du
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Xing-xing Xu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jia-sheng Wang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Fei Xu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wei Lu
- Key Laboratory of Developmental Genes and Human Disease (Ministry of Education of China), Institute of Life Sciences, Southeast University, Nanjing, Jiangsu 211189, China
| | - Shuang Qiu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wei Yang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jian-hong Luo
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
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Buxbaum AR, Yoon YJ, Singer RH, Park HY. Single-molecule insights into mRNA dynamics in neurons. Trends Cell Biol 2015; 25:468-75. [PMID: 26052005 DOI: 10.1016/j.tcb.2015.05.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
Abstract
Targeting of mRNAs to neuronal dendrites and axons plays an integral role in intracellular signaling, development, and synaptic plasticity. Single-molecule imaging of mRNAs in neurons and brain tissue has led to enhanced understanding of mRNA dynamics. Here we discuss aspects of mRNA regulation as revealed by single-molecule detection, which has led to quantitative analyses of mRNA diversity, localization, transport, and translation. These exciting new discoveries propel our understanding of the life of an mRNA in a neuron and how its activity is regulated at the single-molecule level.
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Affiliation(s)
- Adina R Buxbaum
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Young J Yoon
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Hye Yoon Park
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA; Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea.
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Huang WH, Chao HW, Tsai LY, Chung MH, Huang YS. Elevated activation of CaMKIIα in the CPEB3-knockout hippocampus impairs a specific form of NMDAR-dependent synaptic depotentiation. Front Cell Neurosci 2014; 8:367. [PMID: 25404896 PMCID: PMC4217494 DOI: 10.3389/fncel.2014.00367] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/16/2014] [Indexed: 02/05/2023] Open
Abstract
Cytoplasmic polyadenylation element binding protein 3 (CPEB3) is a sequence-specific RNA-binding protein that confines the strength of glutamatergic synapses by translationally downregulating the expression of multiple plasticity-related proteins (PRPs), including the N-methyl-D-aspartate receptor (NMDAR) and the postsynaptic density protein 95 (PSD95). CPEB3 knockout (KO) mice exhibit hippocampus-dependent abnormalities related not only to long-term spatial memory but also to the short-term acquisition and extinction of contextual fear memory. In this study, we identified a specific form of NMDAR-dependent synaptic depotentiation (DPT) that is impaired in the adult CPEB3 KO hippocampus. In parallel, cultured KO neurons also exhibited delayed morphological and biochemical responses under NMDA-induced chemical long-term depression (c-LTD). The c-LTD defects in the KO neurons include elevated activation of calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα), increased Ser831 phosphorylation of GluA1 and slow degradation of PSD95 and GluA1. Because transient pharmacological suppression of CaMKIIα activity during the DPT-initiating phase successfully reversed the LTP in the KO hippocampus, DPT and c-LTD in the two different systems shared common molecular defects due to the absence of CPEB3. Together, our results suggest that CPEB3 deficiency imbalances NMDAR-activated CaMKIIα signaling, which consequently fails to depress synaptic strength under certain stimulation conditions.
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Affiliation(s)
- Wen-Hsuan Huang
- Institute of Biomedical Sciences, Academia Sinica Taipei, Taiwan
| | - Hsu-Wen Chao
- Institute of Biomedical Sciences, Academia Sinica Taipei, Taiwan
| | - Li-Yun Tsai
- Institute of Biomedical Sciences, Academia Sinica Taipei, Taiwan
| | - Ming-Hung Chung
- Interdisciplinary Program of Life Sciences, National Tsing Hua University Hsinchu, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica Taipei, Taiwan
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Cercato MC, Colettis N, Snitcofsky M, Aguirre AI, Kornisiuk EE, Baez MV, Jerusalinsky DA. Hippocampal NMDA receptors and the previous experience effect on memory. ACTA ACUST UNITED AC 2014; 108:263-9. [PMID: 25132342 DOI: 10.1016/j.jphysparis.2014.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 06/19/2014] [Accepted: 08/04/2014] [Indexed: 10/24/2022]
Abstract
N-methyl-D-aspartate receptors (NMDAR) are thought to be responsible for switching synaptic activity specific patterns into long-term changes in synaptic function and structure, which would support learning and memory. Hippocampal NMDAR blockade impairs memory consolidation in rodents, while NMDAR stimulation improves it. Adult rats that explored twice an open field (OF) before a weak though overthreshold training in inhibitory avoidance (IA), expressed IA long-term memory in spite of the hippocampal administration of MK-801, which currently leads to amnesia. Those processes would involve different NMDARs. The selective blockade of hippocampal GluN2B-containing NMDAR with ifenprodil after training promoted memory in an IA task when the training was weak, suggesting that this receptor negatively modulates consolidation. In vivo, after 1h of an OF exposure-with habituation to the environment-, there was an increase in GluN1 and GluN2A subunits in the rat hippocampus, without significant changes in GluN2B. Coincidentally, in vitro, in both rat hippocampal slices and neuron cultures there was an increase in GluN2A-NMDARs surface expression at 30min; an increase in GluN1 and GluN2A levels at about 1h after LTP induction was also shown. We hypothesize that those changes in NMDAR composition could be involved in the "anti-amnesic effect" of the previous OF. Along certain time interval, an increase in GluN1 and GluN2A would lead to an increase in synaptic NMDARs, facilitating synaptic plasticity and memory; while then, an increase in GluN2A/GluN2B ratio could protect the synapse and the already established plasticity, perhaps saving the specific trace.
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Affiliation(s)
- Magalí C Cercato
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - Natalia Colettis
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - Marina Snitcofsky
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - Alejandra I Aguirre
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - Edgar E Kornisiuk
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - María V Baez
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
| | - Diana A Jerusalinsky
- Laboratorio de Neuroplasticidad y Neurotoxinas, Instituto de Biologia Celular y Neurociencia (IBCN), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155 3er Piso, Buenos Aires, Argentina.
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Gardiol A, St Johnston D. Staufen targets coracle mRNA to Drosophila neuromuscular junctions and regulates GluRIIA synaptic accumulation and bouton number. Dev Biol 2014; 392:153-67. [PMID: 24951879 PMCID: PMC4111903 DOI: 10.1016/j.ydbio.2014.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 06/08/2014] [Accepted: 06/09/2014] [Indexed: 11/28/2022]
Abstract
The post-synaptic translation of localised mRNAs has been postulated to underlie several forms of plasticity at vertebrate synapses, but the mechanisms that target mRNAs to these postsynaptic sites are not well understood. Here we show that the evolutionary conserved dsRNA binding protein, Staufen, localises to the postsynaptic side of the Drosophila neuromuscular junction (NMJ), where it is required for the localisation of coracle mRNA and protein. Staufen plays a well-characterised role in the localisation of oskar mRNA to the oocyte posterior, where Staufen dsRNA-binding domain 5 is specifically required for its translation. Removal of Staufen dsRNA-binding domain 5, disrupts the postsynaptic accumulation of Coracle protein without affecting the localisation of cora mRNA, suggesting that Staufen similarly regulates Coracle translation. Tropomyosin II, which functions with Staufen in oskar mRNA localisation, is also required for coracle mRNA localisation, suggesting that similar mechanisms target mRNAs to the NMJ and the oocyte posterior. Coracle, the orthologue of vertebrate band 4.1, functions in the anchoring of the glutamate receptor IIA subunit (GluRIIA) at the synapse. Consistent with this, staufen mutant larvae show reduced accumulation of GluRIIA at synapses. The NMJs of staufen mutant larvae have also a reduced number of synaptic boutons. Altogether, this suggests that this novel Staufen-dependent mRNA localisation and local translation pathway may play a role in the developmentally regulated growth of the NMJ.
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Affiliation(s)
- Alejandra Gardiol
- The WellcomeCRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Daniel St Johnston
- The WellcomeCRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom.
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Ivshina M, Lasko P, Richter JD. Cytoplasmic polyadenylation element binding proteins in development, health, and disease. Annu Rev Cell Dev Biol 2014; 30:393-415. [PMID: 25068488 DOI: 10.1146/annurev-cellbio-101011-155831] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The cytoplasmic polyadenylation element binding (CPEB) proteins are sequence-specific mRNA binding proteins that control translation in development, health, and disease. CPEB1, the founding member of this family, has become an important model for illustrating general principles of translational control by cytoplasmic polyadenylation in gametogenesis, cancer etiology, synaptic plasticity, learning, and memory. Although the biological functions of the other members of this protein family in vertebrates are just beginning to emerge, it is already evident that they, too, mediate important processes, such as cancer etiology and higher cognitive function. In Drosophila, the CPEB proteins Orb and Orb2 play key roles in oogenesis and in neuronal function, as do related proteins in Caenorhabditis elegans and Aplysia. We review the biochemical features of the CPEB proteins, discuss their activities in several biological systems, and illustrate how understanding CPEB activity in model organisms has an important impact on neurological disease.
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Affiliation(s)
- Maria Ivshina
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605;
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Follert P, Cremer H, Béclin C. MicroRNAs in brain development and function: a matter of flexibility and stability. Front Mol Neurosci 2014; 7:5. [PMID: 24570654 PMCID: PMC3916726 DOI: 10.3389/fnmol.2014.00005] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/16/2014] [Indexed: 01/27/2023] Open
Abstract
Fine-tuning of gene expression is a fundamental requirement for development and function of cells and organs. This requirement is particularly obvious in the nervous system where originally common stem cell populations generate thousands of different neuronal and glial cell types in a temporally and quantitatively perfectly orchestrated manner. Moreover, after their generation, young neurons have to connect with pre-determined target neurons through the establishment of functional synapses, either in their immediate environment or at distance. Lastly, brain function depends not only on static circuitries, but on plastic changes at the synaptic level allowing both, learning and memory. It appears evident that these processes necessitate flexibility and stability at the same time. These two contrasting features can only be achieved by complex molecular networks, superposed levels of control and tight interactions between regulatory mechanisms. Interactions between microRNAs and their target mRNAs fulfill these requirements. Here we review recent literature dealing with the involvement of microRNAs in multiple aspects of brain development and connectivity.
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Affiliation(s)
- Philipp Follert
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université - Centre National de la Recherche Scientifique Marseille, France
| | - Harold Cremer
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université - Centre National de la Recherche Scientifique Marseille, France
| | - Christophe Béclin
- Institut de Biologie du Développement de Marseille, Aix-Marseille Université - Centre National de la Recherche Scientifique Marseille, France
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Deletion of CPEB3 enhances hippocampus-dependent memory via increasing expressions of PSD95 and NMDA receptors. J Neurosci 2013; 33:17008-22. [PMID: 24155305 DOI: 10.1523/jneurosci.3043-13.2013] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Long-term memory requires activity-dependent synthesis of plasticity-related proteins (PRPs) to strengthen synaptic efficacy and consequently consolidate memory. Cytoplasmic polyadenylation element binding protein (CPEB)3 is a sequence-specific RNA-binding protein that regulates translation of several PRP RNAs in neurons. To understand whether CPEB3 plays a part in learning and memory, we generated CPEB3 knock-out (KO) mice and found that the null mice exhibited enhanced hippocampus-dependent, short-term fear memory in the contextual fear conditioning test and long-term spatial memory in the Morris water maze. The basal synaptic transmission of Schaffer collateral-CA1 neurons was normal but long-term depression evoked by paired-pulse low-frequency stimulation was modestly facilitated in the juvenile KO mice. Molecular and cellular characterizations revealed several molecules in regulating plasticity of glutamatergic synapses are translationally elevated in the CPEB3 KO neurons, including the scaffolding protein PSD95 and the NMDA receptors along with the known CPEB3 target, GluA1. Together, CPEB3 functions as a negative regulator to confine the strength of glutamatergic synapses by downregulating the expression of multiple PRPs and plays a role underlying certain forms of hippocampus-dependent memories.
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