51
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Emerging Roles for 3' UTRs in Neurons. Int J Mol Sci 2020; 21:ijms21103413. [PMID: 32408514 PMCID: PMC7279237 DOI: 10.3390/ijms21103413] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/06/2020] [Accepted: 05/09/2020] [Indexed: 12/14/2022] Open
Abstract
The 3′ untranslated regions (3′ UTRs) of mRNAs serve as hubs for post-transcriptional control as the targets of microRNAs (miRNAs) and RNA-binding proteins (RBPs). Sequences in 3′ UTRs confer alterations in mRNA stability, direct mRNA localization to subcellular regions, and impart translational control. Thousands of mRNAs are localized to subcellular compartments in neurons—including axons, dendrites, and synapses—where they are thought to undergo local translation. Despite an established role for 3′ UTR sequences in imparting mRNA localization in neurons, the specific RNA sequences and structural features at play remain poorly understood. The nervous system selectively expresses longer 3′ UTR isoforms via alternative polyadenylation (APA). The regulation of APA in neurons and the neuronal functions of longer 3′ UTR mRNA isoforms are starting to be uncovered. Surprising roles for 3′ UTRs are emerging beyond the regulation of protein synthesis and include roles as RBP delivery scaffolds and regulators of alternative splicing. Evidence is also emerging that 3′ UTRs can be cleaved, leading to stable, isolated 3′ UTR fragments which are of unknown function. Mutations in 3′ UTRs are implicated in several neurological disorders—more studies are needed to uncover how these mutations impact gene regulation and what is their relationship to disease severity.
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52
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Alvarez-Castelao B, Tom Dieck S, Fusco CM, Donlin-Asp P, Perez JD, Schuman EM. The switch-like expression of heme-regulated kinase 1 mediates neuronal proteostasis following proteasome inhibition. eLife 2020; 9:52714. [PMID: 32329716 PMCID: PMC7224698 DOI: 10.7554/elife.52714] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/20/2020] [Indexed: 12/20/2022] Open
Abstract
We examined the feedback between the major protein degradation pathway, the ubiquitin-proteasome system (UPS), and protein synthesis in rat and mouse neurons. When protein degradation was inhibited, we observed a coordinate dramatic reduction in nascent protein synthesis in neuronal cell bodies and dendrites. The mechanism for translation inhibition involved the phosphorylation of eIF2α, surprisingly mediated by eIF2α kinase 1, or heme-regulated kinase inhibitor (HRI). Under basal conditions, neuronal expression of HRI is barely detectable. Following proteasome inhibition, HRI protein levels increase owing to stabilization of HRI and enhanced translation, likely via the increased availability of tRNAs for its rare codons. Once expressed, HRI is constitutively active in neurons because endogenous heme levels are so low; HRI activity results in eIF2α phosphorylation and the resulting inhibition of translation. These data demonstrate a novel role for neuronal HRI that senses and responds to compromised function of the proteasome to restore proteostasis.
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Affiliation(s)
| | | | - Claudia M Fusco
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Paul Donlin-Asp
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Julio D Perez
- 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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53
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Biever A, Glock C, Tushev G, Ciirdaeva E, Dalmay T, Langer JD, Schuman EM. Monosomes actively translate synaptic mRNAs in neuronal processes. Science 2020; 367:367/6477/eaay4991. [PMID: 32001627 DOI: 10.1126/science.aay4991] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/29/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022]
Abstract
To accommodate their complex morphology, neurons localize messenger RNAs (mRNAs) and ribosomes near synapses to produce proteins locally. However, a relative paucity of polysomes (considered the active sites of translation) detected in electron micrographs of neuronal processes has suggested a limited capacity for local protein synthesis. In this study, we used polysome profiling together with ribosome footprinting of microdissected rodent synaptic regions to reveal a surprisingly high number of dendritic and/or axonal transcripts preferentially associated with monosomes (single ribosomes). Furthermore, the neuronal monosomes were in the process of active protein synthesis. Most mRNAs showed a similar translational status in the cell bodies and neurites, but some transcripts exhibited differential ribosome occupancy in the compartments. Monosome-preferring transcripts often encoded high-abundance synaptic proteins. Thus, monosome translation contributes to the local neuronal proteome.
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Affiliation(s)
- Anne Biever
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Caspar Glock
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Georgi Tushev
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | | | - Tamas Dalmay
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, Germany.,Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany.
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54
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Dörrbaum AR, Alvarez-Castelao B, Nassim-Assir B, Langer JD, Schuman EM. Proteome dynamics during homeostatic scaling in cultured neurons. eLife 2020; 9:e52939. [PMID: 32238265 PMCID: PMC7117909 DOI: 10.7554/elife.52939] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/22/2020] [Indexed: 12/11/2022] Open
Abstract
Protein turnover, the net result of protein synthesis and degradation, enables cells to remodel their proteomes in response to internal and external cues. Previously, we analyzed protein turnover rates in cultured brain cells under basal neuronal activity and found that protein turnover is influenced by subcellular localization, protein function, complex association, cell type of origin, and by the cellular environment (Dörrbaum et al., 2018). Here, we advanced our experimental approach to quantify changes in protein synthesis and degradation, as well as the resulting changes in protein turnover or abundance in rat primary hippocampal cultures during homeostatic scaling. Our data demonstrate that a large fraction of the neuronal proteome shows changes in protein synthesis and/or degradation during homeostatic up- and down-scaling. More than half of the quantified synaptic proteins were regulated, including pre- as well as postsynaptic proteins with diverse molecular functions.
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Affiliation(s)
- Aline Ricarda Dörrbaum
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Goethe University Frankfurt, Faculty of Biological Sciences, Frankfurt, Germany
| | | | | | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany
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55
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Westerich KJ, Chandrasekaran KS, Gross-Thebing T, Kueck N, Raz E, Rentmeister A. Bioorthogonal mRNA labeling at the poly(A) tail for imaging localization and dynamics in live zebrafish embryos. Chem Sci 2020; 11:3089-3095. [PMID: 33623655 PMCID: PMC7879197 DOI: 10.1039/c9sc05981d] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/21/2020] [Indexed: 12/14/2022] Open
Abstract
Live imaging of mRNA in cells and organisms is important for understanding the dynamic aspects underlying its function.
Live imaging of mRNA in cells and organisms is important for understanding the dynamic aspects underlying its function. Ideally, labeling of mRNA should not alter its structure or function, nor affect the biological system. However, most methods applied in vivo make use of genetically encoded tags and reporters that significantly enhance the size of the mRNA of interest. Alternately, we utilize the 3′ poly(A) tail as a non-coding repetitive hallmark to covalently label mRNAs via bioorthogonal chemistry with different fluorophores from a wide range of spectra without significantly changing the size. We demonstrate that the labeled mRNAs can be visualized in cells and zebrafish embryos, and that they are efficiently translated. Importantly, the labeled mRNAs acquired the proper subcellular localization in developing zebrafish embryos and their dynamics could be tracked in vivo.
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Affiliation(s)
- Kim J Westerich
- Institute of Cell Biology Center for Molecular Biology of Inflammation , University of Münster , D-48149 Münster , Germany .
| | - Karthik S Chandrasekaran
- Institut für Biochemie , Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Str. 2 , 48149 Münster , Germany .
| | - Theresa Gross-Thebing
- Institute of Cell Biology Center for Molecular Biology of Inflammation , University of Münster , D-48149 Münster , Germany .
| | - Nadine Kueck
- Institut für Biochemie , Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Str. 2 , 48149 Münster , Germany .
| | - Erez Raz
- Cells in Motion Interfaculty Centre (CiMIC) , Waldeyerstraße 15 , D-48149 Münster , Germany.,Institute of Cell Biology Center for Molecular Biology of Inflammation , University of Münster , D-48149 Münster , Germany .
| | - Andrea Rentmeister
- Cells in Motion Interfaculty Centre (CiMIC) , Waldeyerstraße 15 , D-48149 Münster , Germany.,Institut für Biochemie , Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Str. 2 , 48149 Münster , Germany .
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56
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Quantification of mRNA translation in live cells using single-molecule imaging. Nat Protoc 2020; 15:1371-1398. [PMID: 32076351 DOI: 10.1038/s41596-019-0284-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/13/2019] [Indexed: 11/09/2022]
Abstract
mRNA translation is a key step in gene expression. Proper regulation of translation efficiency ensures correct protein expression levels in the cell, which is essential to cell function. Different methods used to study translational control in the cell rely on population-based assays that do not provide information about translational heterogeneity between cells or between mRNAs of the same gene within a cell, and generally provide only a snapshot of translation. To study translational heterogeneity and measure translation dynamics, we have developed microscopy-based methods that enable visualization of translation of single mRNAs in live cells. These methods consist of a set of genetic tools, an imaging-based approach and sophisticated computational tools. Using the translation imaging method, one can investigate many new aspects of translation in single living cells, such as translation start-site selection, 3'-UTR (untranslated region) translation and translation-coupled mRNA decay. Here, we describe in detail how to perform such experiments, including reporter design, cell line generation, image acquisition and analysis. This protocol also provides a detailed description of the image analysis pipeline and computational modeling that will enable non-experts to correctly interpret fluorescence measurements. The protocol takes 2-4 d to complete (after cell lines expressing all required transgenes have been generated).
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57
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Optogenetic control of mRNA localization and translation in live cells. Nat Cell Biol 2020; 22:341-352. [PMID: 32066905 DOI: 10.1038/s41556-020-0468-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/13/2020] [Indexed: 02/06/2023]
Abstract
Despite efforts to visualize the spatio-temporal dynamics of single messenger RNAs, the ability to precisely control their function has lagged. This study presents an optogenetic approach for manipulating the localization and translation of specific mRNAs by trapping them in clusters. This clustering greatly amplified reporter signals, enabling endogenous RNA-protein interactions to be clearly visualized in single cells. Functionally, this sequestration reduced the ability of mRNAs to access ribosomes, markedly attenuating protein synthesis. A spatio-temporally resolved analysis indicated that sequestration of endogenous β-actin mRNA attenuated cell motility through the regulation of focal-adhesion dynamics. These results suggest a mechanism highlighting the indispensable role of newly synthesized β-actin protein for efficient cell migration. This platform may be broadly applicable for use in investigating the spatio-temporal activities of specific mRNAs in various biological processes.
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58
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Gharami K, Biswas SC. Glutamate treatment mimics LTP- and LTD-like biochemical activity in viable synaptosome preparation. Neurochem Int 2020; 134:104655. [PMID: 31899196 DOI: 10.1016/j.neuint.2019.104655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/05/2019] [Accepted: 12/29/2019] [Indexed: 01/28/2023]
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are considered to be the cellular mechanisms behind the increase or decrease of synaptic strength respectively. Electrophysiologically induced LTP/LTD is associated with the activation of glutamate receptors in the synaptic terminals resulting in the initiation of biochemical processes in the postsynaptic terminals and thus propagation of synaptic activity. Isolated nerve endings i.e. synaptosome preparation was used to study here, the biochemical phenotypes of LTP and LTD, and glutamate treatment in varying concentration for different time was used to induce those biochemical phenomena. Treatment with 200 μM glutamate showed increased GluA1 phosphorylation at serine 831 and activation of CaMKIIα by phosphorylation at threonine 286 like LTP, whereas 100 μM glutamate treatment showed decrease in GluA1 phosphorylation level at both pGluA1(S831) and pGluA1(S845), and activation of GSK3β by de-phosphorylating pGSK3β at serine 9 like LTD. The 200 μM glutamate treatment was associated with an increase in the local translation of Arc, BDNF, CaMKIIα and Homer1, whereas 100 μM glutamate treatments resulted in decrease in the level of the said synaptic proteins and the effect was blocked by the proteasomal inhibitor, Lactasystin. Both, the local translation and local degradation was sensitive to the Ca2+ chellator, Bapta-AM, indicating that both the phenomena were dependent on the rise in intra-synaptosomal Ca2+, like LTP and LTD. Overall the results of the present study suggest that synaptosomal preparations can be a viable alternative to study mechanisms underlying the biochemical activities of LTP/LTD in short term.
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Affiliation(s)
- Kusumika Gharami
- Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
| | - Subhas C Biswas
- Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
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59
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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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60
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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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61
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Hafner AS, Donlin-Asp PG, Leitch B, Herzog E, Schuman EM. Local protein synthesis is a ubiquitous feature of neuronal pre- and postsynaptic compartments. Science 2019; 364:364/6441/eaau3644. [PMID: 31097639 DOI: 10.1126/science.aau3644] [Citation(s) in RCA: 224] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 01/16/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
There is ample evidence for localization of messenger RNAs (mRNAs) and protein synthesis in neuronal dendrites; however, demonstrations of these processes in presynaptic terminals are limited. We used expansion microscopy to resolve pre- and postsynaptic compartments in rodent neurons. Most presynaptic terminals in the hippocampus and forebrain contained mRNA and ribosomes. We sorted fluorescently labeled mouse brain synaptosomes and then sequenced hundreds of mRNA species present within excitatory boutons. After brief metabolic labeling, >30% of all presynaptic terminals exhibited a signal, providing evidence for ongoing protein synthesis. We tested different classic plasticity paradigms and observed distinct patterns of rapid pre- and/or postsynaptic translation. Thus, presynaptic terminals are translationally competent, and local protein synthesis is differentially recruited to drive compartment-specific phenotypes that underlie different forms of plasticity.
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Affiliation(s)
| | | | - Beulah Leitch
- Department of Anatomy, School of Biomedical Sciences and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Etienne Herzog
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, UMR 5297, F-33000, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, F-33000, Bordeaux, France
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany.
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62
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Armijo-Weingart L, Ketschek A, Sainath R, Pacheco A, Smith GM, Gallo G. Neurotrophins induce fission of mitochondria along embryonic sensory axons. eLife 2019; 8:e49494. [PMID: 31789589 PMCID: PMC6887118 DOI: 10.7554/elife.49494] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/26/2019] [Indexed: 12/30/2022] Open
Abstract
Neurotrophins are growth factors that have a multitude of roles in the nervous system. We report that neurotrophins induce the fission of mitochondria along embryonic chick sensory axons driven by combined PI3K and Mek-Erk signaling. Following an initial burst of fission, a new steady state of neurotrophin-dependent mitochondria length is established. Mek-Erk controls the activity of the fission mediator Drp1 GTPase, while PI3K may contribute to the actin-dependent aspect of fission. Drp1-mediated fission is required for nerve growth factor (NGF)-induced collateral branching in vitro and expression of dominant negative Drp1 impairs the branching of axons in the developing spinal cord in vivo. Fission is also required for NGF-induced mitochondria-dependent intra-axonal translation of the actin regulatory protein cortactin, a previously determined component of NGF-induced branching. Collectively, these observations unveil a novel biological function of neurotrophins; the regulation of mitochondrial fission and steady state mitochondrial length and density in axons.
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Affiliation(s)
- Lorena Armijo-Weingart
- Department of Anatomy and Cell Biology, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
| | - Andrea Ketschek
- Department of Anatomy and Cell Biology, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
| | - Rajiv Sainath
- Department of Anatomy and Cell Biology, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
| | - Almudena Pacheco
- Department of Anatomy and Cell Biology, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
| | - George M Smith
- Department of Neuroscience, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
| | - Gianluca Gallo
- Department of Anatomy and Cell Biology, Shriner Hospitals Pediatric Research CenterTemple University Lewis Katz School of MedicinePhiladelphiaUnited States
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63
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Anhäuser L, Hüwel S, Zobel T, Rentmeister A. Multiple covalent fluorescence labeling of eukaryotic mRNA at the poly(A) tail enhances translation and can be performed in living cells. Nucleic Acids Res 2019; 47:e42. [PMID: 30726958 PMCID: PMC6468298 DOI: 10.1093/nar/gkz084] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/24/2019] [Accepted: 01/31/2019] [Indexed: 12/22/2022] Open
Abstract
Post-transcriptional regulation of gene expression occurs by multiple mechanisms, including subcellular localization of mRNA and alteration of the poly(A) tail length. These mechanisms play crucial roles in the dynamics of cell polarization and embryonic development. Furthermore, mRNAs are emerging therapeutics and chemical alterations to increase their translational efficiency are highly sought after. We show that yeast poly(A) polymerase can be used to install multiple azido-modified adenosine nucleotides to luciferase and eGFP-mRNAs. These mRNAs can be efficiently reacted in a bioorthogonal click reaction with fluorescent reporters without degradation and without sequence alterations in their coding or untranslated regions. Importantly, the modifications in the poly(A) tail impact positively on the translational efficiency of reporter-mRNAs in vitro and in cells. Therefore, covalent fluorescent labeling at the poly(A) tail presents a new way to increase the amount of reporter protein from exogenous mRNA and to label genetically unaltered and translationally active mRNAs.
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Affiliation(s)
- Lea Anhäuser
- Institute of Biochemistry, University of Münster, Wilhelm-Klemm-Straße 2, 48149 Münster, Germany
| | - Sabine Hüwel
- Institute of Biochemistry, University of Münster, Wilhelm-Klemm-Straße 2, 48149 Münster, Germany
| | - Thomas Zobel
- Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany
| | - Andrea Rentmeister
- Institute of Biochemistry, University of Münster, Wilhelm-Klemm-Straße 2, 48149 Münster, Germany.,Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, Germany
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64
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Pacheco A, Merianda TT, Twiss JL, Gallo G. Mechanism and role of the intra-axonal Calreticulin translation in response to axonal injury. Exp Neurol 2019; 323:113072. [PMID: 31669485 DOI: 10.1016/j.expneurol.2019.113072] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/17/2019] [Accepted: 09/27/2019] [Indexed: 12/12/2022]
Abstract
Following injury, sensory axons locally translate mRNAs that encode proteins needed for the response to injury, locally and through retrograde signaling, and for regeneration. In this study, we addressed the mechanism and role of axotomy-induced intra-axonal translation of the ER chaperone Calreticulin. In vivo peripheral nerve injury increased Calreticulin levels in sensory axons. Using an in vitro model system of sensory neurons amenable to mechanistic dissection we provide evidence that axotomy induces local translation of Calreticulin through PERK (protein kinase RNA-like endoplasmic reticulum kinase) mediated phosphorylation of eIF2α by a mechanism that requires both 5' and 3'UTRs (untranslated regions) elements in Calreticulin mRNA. ShRNA mediated depletion of Calreticulin or inhibition of PERK signaling increased axon retraction following axotomy. In contrast, expression of axonally targeted, but not somatically restricted, Calreticulin mRNA decreased retraction and promoted axon regeneration following axotomy in vitro. Collectively, these data indicate that the intra-axonal translation of Calreticulin in response to axotomy serves to minimize the ensuing retraction, and overexpression of axonally targeted Calreticulin mRNA promotes axon regeneration.
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Affiliation(s)
- Almudena Pacheco
- Temple University School of Medicine, Shriners Pediatric Research Center, Department of Anatomy and Cell Biology, 3500 North Broad St, Philadelphia, PA 19140, United States of America.
| | - Tanuja T Merianda
- Drexel University, Department of Biology, Philadelphia, PA 19104, United States of America
| | - Jeffery L Twiss
- University of South Carolina, Department of Biological Sciences, Columbia 29208, SC, United States of America.
| | - Gianluca Gallo
- Temple University School of Medicine, Shriners Pediatric Research Center, Department of Anatomy and Cell Biology, 3500 North Broad St, Philadelphia, PA 19140, United States of America.
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65
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Of Molecules and Mechanisms. J Neurosci 2019; 40:81-88. [PMID: 31630114 DOI: 10.1523/jneurosci.0743-19.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/25/2019] [Accepted: 08/31/2019] [Indexed: 11/21/2022] Open
Abstract
Without question, molecular biology drives modern neuroscience. The past 50 years has been nothing short of revolutionary as key findings have moved the field from correlation toward causation. Most obvious are the discoveries and strategies that have been used to build tools for visualizing circuits, measuring activity, and regulating behavior. Less flashy, but arguably as important are the myriad investigations uncovering the actions of single molecules, macromolecular structures, and integrated machines that serve as the basis for constructing cellular and signaling pathways identified in wide-scale gene or RNA studies and for feeding data into informational networks used in systems biology. This review follows the pathways that were opened in neuroscience by major discoveries and set the stage for the next 50 years.
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66
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Sossin WS, Costa-Mattioli M. Translational Control in the Brain in Health and Disease. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032912. [PMID: 30082469 DOI: 10.1101/cshperspect.a032912] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Translational control in neurons is crucially required for long-lasting changes in synaptic function and memory storage. The importance of protein synthesis control to brain processes is underscored by the large number of neurological disorders in which translation rates are perturbed, such as autism and neurodegenerative disorders. Here we review the general principles of neuronal translation, focusing on the particular relevance of several key regulators of nervous system translation, including eukaryotic initiation factor 2α (eIF2α), the mechanistic (or mammalian) target of rapamycin complex 1 (mTORC1), and the eukaryotic elongation factor 2 (eEF2). These pathways regulate the overall rate of protein synthesis in neurons and have selective effects on the translation of specific messenger RNAs (mRNAs). The importance of these general and specific translational control mechanisms is considered in the normal functioning of the nervous system, particularly during synaptic plasticity underlying memory, and in the context of neurological disorders.
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Affiliation(s)
- Wayne S Sossin
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A-2B4, Canada
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, Texas 77030
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67
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How mRNA Localization and Protein Synthesis Sites Influence Dendritic Protein Distribution and Dynamics. Neuron 2019; 103:1109-1122.e7. [PMID: 31350097 DOI: 10.1016/j.neuron.2019.06.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 02/21/2019] [Accepted: 06/22/2019] [Indexed: 01/23/2023]
Abstract
Proteins drive the function of neuronal synapses. The synapses are distributed throughout the dendritic arbor, often hundreds of micrometers away from the soma. It is still unclear how somatic and dendritic sources of proteins shape protein distribution and respectively contribute to local protein changes during synaptic plasticity. Here, we present a unique computational framework describing for a given protein species the dendritic distribution of the mRNA and the corresponding protein in a dendrite. Using CaMKIIα as a test case, our model reveals the key role active transport plays in the maintenance of dendritic mRNA and protein levels and predicts the short and long timescales of protein dynamics. Our model reveals the fundamental role of mRNA localization and dendritic mRNA translation in synaptic maintenance and plasticity in distal compartments. We developed a web application for neuroscientists to explore the dynamics of the mRNA or protein of interest.
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68
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A genetically encodable cell-type-specific protein synthesis inhibitor. Nat Methods 2019; 16:699-702. [DOI: 10.1038/s41592-019-0468-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/21/2019] [Indexed: 11/08/2022]
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69
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Local translation in neurons: visualization and function. Nat Struct Mol Biol 2019; 26:557-566. [PMID: 31270476 DOI: 10.1038/s41594-019-0263-5] [Citation(s) in RCA: 288] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/30/2019] [Indexed: 01/01/2023]
Abstract
Neurons are among the most compartmentalized and interactive of all cell types. Like all cells, neurons use proteins as the main sensors and effectors. The modification of the proteome in axons and dendrites is used to guide the formation of synaptic connections and to store information. In this Review, we discuss the data indicating that an important source of protein for dendrites, axons and their associated elements is provided by the local synthesis of proteins. We review the data indicating the presence of the machinery required for protein synthesis, the direct visualization and demonstration of protein synthesis, and the established functional roles for local translation for many different neuronal functions. Finally, we consider the open questions and future directions in this field.
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70
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Böger C, Hafner AS, Schlichthärle T, Strauss MT, Malkusch S, Endesfelder U, Jungmann R, Schuman EM, Heilemann M. Super-resolution imaging and estimation of protein copy numbers at single synapses with DNA-point accumulation for imaging in nanoscale topography. NEUROPHOTONICS 2019; 6:035008. [PMID: 31637284 PMCID: PMC6795074 DOI: 10.1117/1.nph.6.3.035008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/31/2019] [Indexed: 05/25/2023]
Abstract
In the brain, the strength of each individual synapse is defined by the complement of proteins present or the "local proteome." Activity-dependent changes in synaptic strength are the result of changes in this local proteome and posttranslational protein modifications. Although most synaptic proteins have been identified, we still know little about protein copy numbers in individual synapses and variations between synapses. We use DNA-point accumulation for imaging in nanoscale topography as a single-molecule super-resolution imaging technique to visualize and quantify protein copy numbers in single synapses. The imaging technique provides near-molecular spatial resolution, is unaffected by photobleaching, enables imaging of large field of views, and provides quantitative molecular information. We demonstrate these benefits by accessing copy numbers of surface AMPA-type receptors at single synapses of rat hippocampal neurons along dendritic segments.
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Affiliation(s)
- Carolin Böger
- Goethe University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | | | - Thomas Schlichthärle
- Ludwig Maximilian University, Center for Nanoscience, Faculty of Physics, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maximilian T. Strauss
- Ludwig Maximilian University, Center for Nanoscience, Faculty of Physics, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sebastian Malkusch
- Goethe University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | | | - Ralf Jungmann
- Ludwig Maximilian University, Center for Nanoscience, Faculty of Physics, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | - Mike Heilemann
- Goethe University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
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71
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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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72
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Zhang F, Kang Y, Wang M, Li Y, Xu T, Yang W, Song H, Wu H, Shu Q, Jin P. Fragile X mental retardation protein modulates the stability of its m6A-marked messenger RNA targets. Hum Mol Genet 2019; 27:3936-3950. [PMID: 30107516 DOI: 10.1093/hmg/ddy292] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/07/2018] [Indexed: 12/12/2022] Open
Abstract
N6-methyladenosine (m6A) is the most prevalent internal modification of mammalian messenger RNAs (mRNAs) and long non-coding RNAs. The biological functions of this reversible RNA modification can be interpreted by cytoplasmic and nuclear 'm6A reader' proteins to fine-tune gene expression, such as mRNA degradation and translation initiation. Here we profiled transcriptome-wide m6A sites in adult mouse cerebral cortex, underscoring that m6A is a widespread epitranscriptomic modification in brain. Interestingly, the mRNA targets of fragile X mental retardation protein (FMRP), a selective RNA-binding protein, are enriched for m6A marks. Loss of functional FMRP leads to Fragile X syndrome (FXS), the most common inherited form of intellectual disability. Transcriptome-wide gene expression profiling identified 2035 genes differentially expressed in the absence of FMRP in cortex, and 92.5% of 174 downregulated FMRP targets are marked by m6A. Biochemical analyses indicate that FMRP binds to the m6A sites of its mRNA targets and interacts with m6A reader YTHDF2 in an RNA-independent manner. FMRP maintains the stability of its mRNA targets while YTHDF2 promotes the degradation of these mRNAs. These data together suggest that FMRP regulates the stability of its m6A-marked mRNA targets through YTHDF2, which could potentially contribute to the molecular pathogenesis of FXS.
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Affiliation(s)
- Feiran Zhang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Yunhee Kang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Mengli Wang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Tianlei Xu
- Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Wei Yang
- Department of Neurology, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Hongjun Song
- Department of Neuroscience, Mahoney Institute for Neurosciences, Institute for Regenerative Medicine and The Epigenetics Institute, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Qiang Shu
- The Children's Hospital and Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
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73
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Fluorescence Imaging Methods to Investigate Translation in Single Cells. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032722. [PMID: 30082468 DOI: 10.1101/cshperspect.a032722] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Translation is the fundamental biological process that converts the genetic information in messenger RNAs (mRNAs) into functional proteins. Translation regulation allows cells to control when, where, and how many proteins are synthesized. Much of what we know about translation comes from ensemble approaches that measure the average of many cells. The cellular and molecular heterogeneity in the regulation of translation remains largely elusive. Fluorescence microscopy allows interrogation of biological problems with single-molecule, single-cell sensitivity. In recent years, improved design of reagents and microscopy tools has led to improved spatial and temporal resolution of translation imaging. It is now possible to track global translation in specific subcellular compartments and follow the translation dynamics of single transcripts. Highlighted here is the recent progress in translation imaging with emphasis on in vivo translation dynamics. These tools will be invaluable to the study of translation regulation.
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74
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Li Q, Wu X, Na X, Ge B, Wu Q, Guo X, Ntim M, Zhang Y, Sun Y, Yang J, Xiao Z, Zhao J, Li S. Impaired Cognitive Function and Altered Hippocampal Synaptic Plasticity in Mice Lacking Dermatan Sulfotransferase Chst14/D4st1. Front Mol Neurosci 2019; 12:26. [PMID: 30853887 PMCID: PMC6396735 DOI: 10.3389/fnmol.2019.00026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 01/21/2019] [Indexed: 12/23/2022] Open
Abstract
Chondroitin sulfate (CS) and dermatan sulfate (DS) proteoglycans (PGs) are major extracellular matrix (ECM) components of the central nervous system (CNS). A large body of evidence has shown that CSPGs/DSPGs play critical roles in neuronal growth, axon guidance, and plasticity in the developing and mature CNS. It has been proposed that these PGs exert their function through specific interaction of CS/DS chains with its binding partners in a manner that depends on the sulfation patterns of CS/DS. It has been reported that dermatan 4-O-sulfotransferase-1 (Chst14/D4st1) specific for DS, but not chondroitin 4-O-sulfotransferase-1 (Chst11/C4st1) specific for CS, regulates proliferation and neurogenesis of neural stem cells (NSCs), indicating that CS and DS play distinct roles in the self-renewal and differentiation of NSCs. However, it remains unknown whether specific sulfation profiles of DS has any effect on CNS plasticity. In the present study, Chst14/D4st1-deficient (Chst14−/−) mice was employed to investigate the involvement of DS in synaptic plasticity. First, behavior study using Morris Water Maze (MWM) showed that the spatial learning and memory of Chst14−/− mice was impaired when compared to their wild type (WT) littermates. Corroborating the behavior result, long-term potentiation (LTP) at the hippocampal CA3-CA1 connection was reduced in Chst14−/− mice compared to the WT mice. Finally, the protein levels of N-Methyl-D-aspartate (NMDA) receptor, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, postsynaptic density 95 (PSD95), growth associated protein 43 (GAP-43), synaptophysin (SYN) and N-ethylmaleimide sensitive factor (NSF) which are important in synaptic plasticity were examined and Chst14/D4st1 deficiency was shown to significantly reduce the expression of these proteins in the hippocampus. Further studies revealed that Akt/mammalian target rapamycin (mTOR) pathway proteins, including protein kinase B (p-Akt), p-mTOR and p-S6, were significantly lower in Chst14−/− mice, which might contribute to the decreased protein expression. Together, this study reveals that specific sulfation of DS is critical in synaptic plasticity of the hippocampus and learning and memory, which might be associated with the changes in the expression of glutamate receptors and other synaptic proteins though Akt/mTOR pathway.
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Affiliation(s)
- Qifa Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Xuefei Wu
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Xueyan Na
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Biying Ge
- National-Local Joint Engineering Research Center for Drug-Research and Development (R & D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Qiong Wu
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Xuewen Guo
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Michael Ntim
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Yue Zhang
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Yiping Sun
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
| | - Jinyi Yang
- Department of Urology, Dalian Friendship Hospital, Dalian, China
| | - Zhicheng Xiao
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Jie Zhao
- National-Local Joint Engineering Research Center for Drug-Research and Development (R & D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Shao Li
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, Dalian Medical University, Dalian, China
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75
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Middleton SA, Eberwine J, Kim J. Comprehensive catalog of dendritically localized mRNA isoforms from sub-cellular sequencing of single mouse neurons. BMC Biol 2019; 17:5. [PMID: 30678683 PMCID: PMC6344992 DOI: 10.1186/s12915-019-0630-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023] Open
Abstract
Background RNA localization involves cis-motifs that are recognized by RNA-binding proteins (RBP), which then mediate localization to specific sub-cellular compartments. RNA localization is critical for many different cell functions, e.g., in neuronal dendrites, localization is a critical step for long-lasting synaptic potentiation. However, there is little consensus regarding which RNAs are localized and the role of alternative isoforms in localization. A comprehensive catalog of localized RNA can help dissect RBP/RNA interactions and localization motifs. Here, we utilize a single cell sub-cellular RNA sequencing approach to profile differentially localized RNAs from individual cells across multiple single cells to help identify a consistent set of localized RNA in mouse neurons. Results Using independent RNA sequencing from soma and dendrites of the same neuron, we deeply profiled the sub-cellular transcriptomes to assess the extent and variability of dendritic RNA localization in individual hippocampal neurons, including an assessment of differential localization of alternative 3′UTR isoforms. We identified 2225 dendritic RNAs, including 298 cases of 3′UTR isoform-specific localization. We extensively analyzed the localized RNAs for potential localization motifs, finding that B1 and B2 SINE elements are up to 5.7 times more abundant in localized RNA 3′UTRs than non-localized, and also functionally characterized the localized RNAs using protein structure analysis. Conclusion We integrate our list of localized RNAs with the literature to provide a comprehensive list of known dendritically localized RNAs as a resource. This catalog of transcripts, including differentially localized isoforms and computationally hypothesized localization motifs, will help investigators further dissect the genome-scale mechanism of RNA localization. Electronic supplementary material The online version of this article (10.1186/s12915-019-0630-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sarah A Middleton
- Graduate Program in Genomics and Computational Biology, Biomedical Graduate Studies, University of Pennsylvania, 160 BRB II/III - 421 Curie Blvd, Philadelphia, PA, 19104-6064, USA.,Present Address: Computational Biology, Target Sciences, GlaxoSmithKline R&D, 1250 S. Collegeville Road, Collegeville, PA, 19426, USA
| | - James Eberwine
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, 829 BRB II/III, 421 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Junhyong Kim
- Graduate Program in Genomics and Computational Biology, Biomedical Graduate Studies, University of Pennsylvania, 160 BRB II/III - 421 Curie Blvd, Philadelphia, PA, 19104-6064, USA. .,Department of Biology, University of Pennsylvania, 415 S. University Ave, Philadelphia, PA, 19104, USA.
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76
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Garcez Palha I, Anselme I, Schneider-Maunoury S, Giudicelli F. An in vivo translation-reporter system for the study of protein synthesis in zebrafish embryos. Biol Open 2018; 7:bio.039362. [PMID: 30404898 PMCID: PMC6310896 DOI: 10.1242/bio.039362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Control of gene expression at the translation level is increasingly regarded as a key feature in many biological processes. Simple, inexpensive and reliable procedures to visualize sites of protein production are required to allow observation of the spatiotemporal patterns of mRNA translation at subcellular resolution. We present a method, named SPoT (for Subcellular Patterns of Translation), developed upon the original TimeStamp technique (
Lin et al., 2008), consisting in the expression of a fluorescent protein fused to a tagged, self-cleavable protease domain. The addition of a cell-permeable protease inhibitor instantly stabilizes newly produced tagged protein allowing us to distinguish recently synthesized proteins from pre-existing ones. After a brief protease inhibitor treatment, the ratio of tagged versus non-tagged forms is highest at sites where proteins are the most recent, i.e. sites of synthesis. Therefore, by comparing tagged and non-tagged proteins it is possible to spotlight sites of translation. By specifically expressing the SPoT cassette in neurons of transgenic zebrafish embryos, we reveal sites of neuronal protein synthesis in diverse cellular compartments during early development. Summary: We describe a transgene-based method, SPoT, that reveals subcellular sites of protein synthesis in neurons of wholemount zebrafish embryos.
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Affiliation(s)
- Inês Garcez Palha
- Sorbonne Université, CNRS UMR7622, Inserm U1156, Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du développement (LBD), F-75005 Paris, France
| | - Isabelle Anselme
- Sorbonne Université, CNRS UMR7622, Inserm U1156, Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du développement (LBD), F-75005 Paris, France
| | - Sylvie Schneider-Maunoury
- Sorbonne Université, CNRS UMR7622, Inserm U1156, Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du développement (LBD), F-75005 Paris, France
| | - François Giudicelli
- Sorbonne Université, CNRS UMR7622, Inserm U1156, Institut de Biologie Paris-Seine (IBPS), Laboratoire de Biologie du développement (LBD), F-75005 Paris, France
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77
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Elamri I, Heumüller M, Herzig L, Stirnal E, Wachtveitl J, Schuman EM, Schwalbe H. A New Photocaged Puromycin for an Efficient Labeling of Newly Translated Proteins in Living Neurons. Chembiochem 2018; 19:2458-2464. [DOI: 10.1002/cbic.201800408] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/11/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Isam Elamri
- Center for Biomolecular Magnetic ResonanceInstitute of Organic Chemistry and Chemical BiologyGoethe-University Frankfurt am Main Max-von-Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Maximilian Heumüller
- Department of Synaptic Plasticity, MPI for Brain ResearchGoethe-University Frankfurt am Main Max-von-Laue-Strasse 4 60438 Frankfurt am Mail Germany
| | - Lisa‐M. Herzig
- Institute of Physical and Theoretical ChemistryGoethe-University Frankfurt am Main Max-von-Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Elke Stirnal
- Center for Biomolecular Magnetic ResonanceInstitute of Organic Chemistry and Chemical BiologyGoethe-University Frankfurt am Main Max-von-Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical ChemistryGoethe-University Frankfurt am Main Max-von-Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Erin M. Schuman
- Department of Synaptic Plasticity, MPI for Brain ResearchGoethe-University Frankfurt am Main Max-von-Laue-Strasse 4 60438 Frankfurt am Mail Germany
| | - Harald Schwalbe
- Center for Biomolecular Magnetic ResonanceInstitute of Organic Chemistry and Chemical BiologyGoethe-University Frankfurt am Main Max-von-Laue-Strasse 7 60438 Frankfurt am Main Germany
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78
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Sahoo PK, Lee SJ, Jaiswal PB, Alber S, Kar AN, Miller-Randolph S, Taylor EE, Smith T, Singh B, Ho TSY, Urisman A, Chand S, Pena EA, Burlingame AL, Woolf CJ, Fainzilber M, English AW, Twiss JL. Axonal G3BP1 stress granule protein limits axonal mRNA translation and nerve regeneration. Nat Commun 2018; 9:3358. [PMID: 30135423 PMCID: PMC6105716 DOI: 10.1038/s41467-018-05647-x] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/12/2018] [Indexed: 12/17/2022] Open
Abstract
Critical functions of intra-axonally synthesized proteins are thought to depend on regulated recruitment of mRNA from storage depots in axons. Here we show that axotomy of mammalian neurons induces translation of stored axonal mRNAs via regulation of the stress granule protein G3BP1, to support regeneration of peripheral nerves. G3BP1 aggregates within peripheral nerve axons in stress granule-like structures that decrease during regeneration, with a commensurate increase in phosphorylated G3BP1. Colocalization of G3BP1 with axonal mRNAs is also correlated with the growth state of the neuron. Disrupting G3BP functions by overexpressing a dominant-negative protein activates intra-axonal mRNA translation, increases axon growth in cultured neurons, disassembles axonal stress granule-like structures, and accelerates rat nerve regeneration in vivo. G3BP1 is RasGAP SH3 domain binding protein 1 that interacts with 48S pre-initiation complex when translation is stalled. Here, Twiss and colleagues show that neuronal G3BP1 can negatively regulate axonal mRNA translation, and inhibit axonal regeneration after injury.
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Affiliation(s)
- Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA
| | - Seung Joon Lee
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA
| | - Poonam B Jaiswal
- Department of Cell Biology, Emory University College of Medicine, Atlanta, 30322, GA, USA
| | - Stefanie Alber
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA
| | | | - Elizabeth E Taylor
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA
| | - Terika Smith
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA
| | - Bhagat Singh
- FM Kirby Neurobiology Center and Boston Children's Hospital and Harvard Medical School, Boston, 02115, MA, USA
| | - Tammy Szu-Yu Ho
- FM Kirby Neurobiology Center and Boston Children's Hospital and Harvard Medical School, Boston, 02115, MA, USA
| | - Anatoly Urisman
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, 94158, CA, USA
| | - Shreya Chand
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, 94158, CA, USA
| | - Edsel A Pena
- Department of Statistics, University of South Carolina, Columbia, 29208, SC, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, 94158, CA, USA
| | - Clifford J Woolf
- FM Kirby Neurobiology Center and Boston Children's Hospital and Harvard Medical School, Boston, 02115, MA, USA
| | - Mike Fainzilber
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Arthur W English
- Department of Cell Biology, Emory University College of Medicine, Atlanta, 30322, GA, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, 29208, SC, USA.
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79
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Dörrbaum AR, Kochen L, Langer JD, Schuman EM. Local and global influences on protein turnover in neurons and glia. eLife 2018; 7:34202. [PMID: 29914620 PMCID: PMC6008053 DOI: 10.7554/elife.34202] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 05/19/2018] [Indexed: 12/31/2022] Open
Abstract
Regulation of protein turnover allows cells to react to their environment and maintain homeostasis. Proteins can show different turnover rates in different tissue, but little is known about protein turnover in different brain cell types. We used dynamic SILAC to determine half-lives of over 5100 proteins in rat primary hippocampal cultures as well as in neuron-enriched and glia-enriched cultures ranging from <1 to >20 days. In contrast to synaptic proteins, membrane proteins were relatively shorter-lived and mitochondrial proteins were longer-lived compared to the population. Half-lives also correlate with protein functions and the dynamics of the complexes they are incorporated in. Proteins in glia possessed shorter half-lives than the same proteins in neurons. The presence of glia sped up or slowed down the turnover of neuronal proteins. Our results demonstrate that both the cell-type of origin as well as the nature of the extracellular environment have potent influences on protein turnover.
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Affiliation(s)
- Aline R Dörrbaum
- Max Planck Institute for Brain Research, Frankfurt, Germany.,Faculty of Biological Sciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Lisa Kochen
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, Germany.,Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany
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80
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de Paula Martins R, Glaser V, Aguiar AS, de Paula Ferreira PM, Ghisoni K, da Luz Scheffer D, Lanfumey L, Raisman-Vozari R, Corti O, De Paul AL, da Silva RA, Latini A. De novo tetrahydrobiopterin biosynthesis is impaired in the inflammed striatum of parkin (-/-) mice. Cell Biol Int 2018; 42:725-733. [PMID: 29624777 DOI: 10.1002/cbin.10969] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 03/31/2018] [Indexed: 11/09/2022]
Abstract
Parkinson's disease (PD), the second-most prevalent neurodegenerative disease, is primarily characterized by neurodegeneration in the substantia nigra pars compacta, resulting in motor impairment. Loss-of-function mutations in parkin are the major cause of the early onset familial form of the disease. Although rodents deficient in parkin (parkin(-/-) ) have some dopaminergic system dysfunction associated with central oxidative stress and energy metabolism deficiencies, these animals only display nigrostriatal pathway degeneration under inflammatory conditions. This study investigated the impact of the inflammatory stimulus induced by lypopolisaccharide (LPS) on tetrahydrobiopterin (BH4) synthesizing enzymes (de novo and salvage pathways), since this cofactor is essential for dopamine synthesis. The mitochondrial content and architecture was investigated in the striatum of LPS-exposed parkin(-/-) mice. As expected, the LPS (0.33 mg/kg; i.p.) challenge compromised spontaneous locomotion and social interaction with juvenile parkin(-/-) and WT mice. Moreover, the genotype impacted the kinetics of the investigation of the juvenile. The inflammatory scenario did not induce apparent changes in mitochondrial ultrastructure; however, it increased the quantity of mitochondria, which were of smaller size, and provoked the perinuclear distribution of the organelle. Furthermore, the BH4 de novo biosynthetic pathway failed to be up-regulated in the LPS challenge, a well-known stimulus for its activation. The LPS treatment increased sepiapterin reductase (SPR) expression, suggesting compensation by the salvage pathway. This might indicate that dopamine synthesis is compromised in parkin(-/-) mice under inflammatory conditions. Finally, this scenario impaired the striatal expression of the transcription factor BDNF, possibly favoring cell death.
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Affiliation(s)
- Roberta de Paula Martins
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Viviane Glaser
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Aderbal S Aguiar
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Priscila Maximiliano de Paula Ferreira
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Karina Ghisoni
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Débora da Luz Scheffer
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Laurence Lanfumey
- INSERM UMR 894, Centre de Psychiatrie et Neurosciences, Paris, France
| | - Rita Raisman-Vozari
- Institut de Cerveau et de la Moelle Epinière, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Olga Corti
- Institut de Cerveau et de la Moelle Epinière, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Ana Lucia De Paul
- Centro de Microscopia Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Rodrigo Augusto da Silva
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Faculdade de Odontologia, Área de Pesquisa em Epigenética, Universidade Paulista, São Paulo, Brazil
| | - Alexandra Latini
- Laboratório de Bioenergética e Estresse Oxidativo-LABOX, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
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81
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Stefanik MT, Sakas C, Lee D, Wolf ME. Ionotropic and metabotropic glutamate receptors regulate protein translation in co-cultured nucleus accumbens and prefrontal cortex neurons. Neuropharmacology 2018; 140:62-75. [PMID: 30077883 DOI: 10.1016/j.neuropharm.2018.05.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 05/15/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023]
Abstract
The regulation of protein translation by glutamate receptors and its role in plasticity have been extensively studied in the hippocampus. In contrast, very little is known about glutamatergic regulation of translation in nucleus accumbens (NAc) medium spiny neurons (MSN), despite their critical role in addiction-related plasticity and recent evidence that protein translation contributes to this plasticity. We used a co-culture system, containing NAc MSNs and prefrontal cortex (PFC) neurons, and fluorescent non-canonical amino acid tagging (FUNCAT) to visualize newly synthesized proteins in neuronal processes of NAc MSNs and PFC pyramidal neurons. First, we verified that the FUNCAT signal reflects new protein translation. Next, we examined the regulation of translation by group I metabotropic glutamate receptors (mGluRs) and ionotropic glutamate receptors by incubating co-cultures with agonists or antagonists during the 2-h period of non-canonical amino acid labeling. In NAc MSNs, basal translation was modestly reduced by blocking Ca2+-permeable AMPARs whereas blocking all AMPARs or suppressing constitutive mGluR5 signaling enhanced translation. Activating group I mGluRs with dihydroxyphenylglycine increased translation in an mGluR1-dependent manner in NAc MSNs and PFC pyramidal neurons. Disinhibiting excitatory transmission with bicuculline also increased translation. In MSNs, this was reversed by antagonists of mGluR1, mGluR5, AMPARs or NMDARs. In PFC neurons, AMPAR or NMDAR antagonists blocked bicuculline-stimulated translation. Our study, the first to examine glutamatergic regulation of translation in MSNs, demonstrates regulatory mechanisms specific to MSNs that depend on the level of neuronal activation. This sets the stage for understanding how translation may be altered in addiction.
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Affiliation(s)
- Michael T Stefanik
- Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Courtney Sakas
- Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Dennis Lee
- Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Marina E Wolf
- Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA.
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82
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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: 225] [Impact Index Per Article: 37.5] [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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83
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Banerjee A, Ifrim MF, Valdez AN, Raj N, Bassell GJ. Aberrant RNA translation in fragile X syndrome: From FMRP mechanisms to emerging therapeutic strategies. Brain Res 2018; 1693:24-36. [PMID: 29653083 PMCID: PMC7377270 DOI: 10.1016/j.brainres.2018.04.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/30/2018] [Accepted: 04/06/2018] [Indexed: 02/07/2023]
Abstract
Research in the past decades has unfolded the multifaceted role of Fragile X mental retardation protein (FMRP) and how its absence contributes to the pathophysiology of Fragile X syndrome (FXS). Excess signaling through group 1 metabotropic glutamate receptors is commonly observed in mouse models of FXS, which in part is attributed to dysregulated translation and downstream signaling. Considering the wide spectrum of cellular and physiologic functions that loss of FMRP can affect in general, it may be advantageous to pursue disease mechanism based treatments that directly target translational components or signaling factors that regulate protein synthesis. Various FMRP targets upstream and downstream of the translational machinery are therefore being investigated to further our understanding of the molecular mechanism of RNA and protein synthesis dysregulation in FXS as well as test their potential role as therapeutic interventions to alleviate FXS associated symptoms. In this review, we will broadly discuss recent advancements made towards understanding the role of FMRP in translation regulation, new pre-clinical animal models with FMRP targets located at different levels of the translational and signal transduction pathways for therapeutic intervention as well as future use of stem cells to model FXS associated phenotypes.
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Affiliation(s)
- Anwesha Banerjee
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Marius F Ifrim
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Arielle N Valdez
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nisha Raj
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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84
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Ortiz R, Georgieva MV, Gutiérrez S, Pedraza N, Fernández-Moya SM, Gallego C. Recruitment of Staufen2 Enhances Dendritic Localization of an Intron-Containing CaMKIIα mRNA. Cell Rep 2018; 20:13-20. [PMID: 28683307 DOI: 10.1016/j.celrep.2017.06.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/30/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023] Open
Abstract
Regulation of mRNA localization is a conserved cellular process observed in many types of cells and organisms. Asymmetrical mRNA distribution plays a particularly important role in the nervous system, where local translation of localized mRNA represents a key mechanism in synaptic plasticity. CaMKIIα is a very abundant mRNA detected in neurites, consistent with its crucial role at glutamatergic synapses. Here, we report the presence of CaMKIIα mRNA isoforms that contain intron i16 in dendrites, RNA granules, and synaptoneurosomes from primary neurons and brain. This subpopulation of unspliced mRNA preferentially localizes to distal dendrites in a synaptic-activity-dependent manner. Staufen2, a well-established marker of RNA transport in dendrites, interacts with intron i16 sequences and enhances its distal dendritic localization, pointing to the existence of intron-mediated mechanisms in the molecular pathways that modulate dendritic transport and localization of synaptic mRNAs.
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Affiliation(s)
- Raúl Ortiz
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Maya V Georgieva
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Sara Gutiérrez
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain
| | - Neus Pedraza
- Institut de Recerca Biomèdica de Lleida (IRBLleida), Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, 25198 Lleida, Catalonia, Spain
| | - Sandra M Fernández-Moya
- Biomedical Center, Division of Anatomy and Cell Biology, Ludwig Maximilians University, 82152 Planegg-Martinsried, Germany
| | - Carme Gallego
- Molecular Biology Institute of Barcelona (IBMB-CSIC), 08028 Barcelona, Catalonia, Spain.
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85
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Schanzenbächer CT, Langer JD, Schuman EM. Time- and polarity-dependent proteomic changes associated with homeostatic scaling at central synapses. eLife 2018; 7:33322. [PMID: 29447110 PMCID: PMC5814146 DOI: 10.7554/elife.33322] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/27/2018] [Indexed: 12/12/2022] Open
Abstract
In homeostatic scaling at central synapses, the depth and breadth of cellular mechanisms that detect the offset from the set-point, detect the duration of the offset and implement a cellular response are not well understood. To understand the time-dependent scaling dynamics we treated cultured rat hippocampal cells with either TTX or bicucculline for 2 hr to induce the process of up- or down-scaling, respectively. During the activity manipulation we metabolically labeled newly synthesized proteins using BONCAT. We identified 168 newly synthesized proteins that exhibited significant changes in expression. To obtain a temporal trajectory of the response, we compared the proteins synthesized within 2 hr or 24 hr of the activity manipulation. Surprisingly, there was little overlap in the significantly regulated newly synthesized proteins identified in the early- and integrated late response datasets. There was, however, overlap in the functional categories that are modulated early and late. These data indicate that within protein function groups, different proteomic choices can be made to effect early and late homeostatic responses that detect the duration and polarity of the activity manipulation. The brain can store information by changing the strength of connections between neurons, also known as synapses. When two neurons at a synapse are active at the same time, the synapse becomes stronger. This enables the first neuron to activate the second more easily. But it also means that the two neurons will now be active at the same time more often, which will tend to make the synapse even stronger. If this process continues unchecked, the synapse will keep getting stronger until no further changes in strength are possible. This will make it harder for the brain to form new memories. To prevent this from happening, the brain responds to prolonged changes in the activity of neurons by adjusting the strength of synapses in the opposite direction. If neurons are too active for an extended period of time, the brain reduces the strength of synapses. If neurons show too little activity, the brain increases the strength of synapses. This process is known as homeostatic scaling, and the brain achieves it by adjusting the number and/or type of proteins present at synapses. Schanzenbächer et al. now reveal the changes in synaptic proteins that occur in response to a two-hour increase or decrease in neuronal activity. These changes can be tracked in the laboratory by growing cells in a petri dish in the presence of modified amino acids, the building blocks of proteins. Any new proteins the cells produce will contain the modified amino acids, making them easy to spot. Schanzenbächer et al. applied this technique to neurons obtained from the rat hippocampus, a region of the brain involved in learning and memory. Bathing the neurons for two hours in chemicals that either enhanced or reduced their activity, triggered changes in more than 150 proteins. Schanzenbächer et al. compared these results to those of a previous experiment in which neuronal activity had been manipulated for 24 hours. Each set of conditions produced a characteristic profile of protein activity. The profiles indicated whether the activity in neurons had increased or decreased, and whether the changes had lasted for two hours or 24 hours. These findings may provide insights into disease states in which there is too much or too little brain activity.
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Affiliation(s)
- Christoph T Schanzenbächer
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany.,Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany.,Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
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86
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Mathur C, Johnson KR, Tong BA, Miranda P, Srikumar D, Basilio D, Latorre R, Bezanilla F, Holmgren M. Demonstration of ion channel synthesis by isolated squid giant axon provides functional evidence for localized axonal membrane protein translation. Sci Rep 2018; 8:2207. [PMID: 29396520 PMCID: PMC5797086 DOI: 10.1038/s41598-018-20684-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/18/2018] [Indexed: 12/18/2022] Open
Abstract
Local translation of membrane proteins in neuronal subcellular domains like soma, dendrites and axon termini is well-documented. In this study, we isolated the electrical signaling unit of an axon by dissecting giant axons from mature squids (Dosidicus gigas). Axoplasm extracted from these axons was found to contain ribosomal RNAs, ~8000 messenger RNA species, many encoding the translation machinery, membrane proteins, translocon and signal recognition particle (SRP) subunits, endomembrane-associated proteins, and unprecedented proportions of SRP RNA (~68% identical to human homolog). While these components support endoplasmic reticulum-dependent protein synthesis, functional assessment of a newly synthesized membrane protein in axolemma of an isolated axon is technically challenging. Ion channels are ideal proteins for this purpose because their functional dynamics can be directly evaluated by applying voltage clamp across the axon membrane. We delivered in vitro transcribed RNA encoding native or Drosophila voltage-activated Shaker KV channel into excised squid giant axons. We found that total K+ currents increased in both cases; with added inactivation kinetics on those axons injected with RNA encoding the Shaker channel. These results provide unambiguous evidence that isolated axons can exhibit de novo synthesis, assembly and membrane incorporation of fully functional oligomeric membrane proteins.
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Affiliation(s)
- Chhavi Mathur
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Brian A Tong
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Pablo Miranda
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Deepa Srikumar
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Daniel Basilio
- Facultad de Ciencias, Universidad de Chile, Santiago, 7750000, Chile
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, 2366103, Chile.
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Gordon Center for Integrative Sciences, Chicago, Illinois, 60637, USA.
| | - Miguel Holmgren
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892, USA.
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87
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Nakayama K, Ohashi R, Shinoda Y, Yamazaki M, Abe M, Fujikawa A, Shigenobu S, Futatsugi A, Noda M, Mikoshiba K, Furuichi T, Sakimura K, Shiina N. RNG105/caprin1, an RNA granule protein for dendritic mRNA localization, is essential for long-term memory formation. eLife 2017; 6. [PMID: 29157358 PMCID: PMC5697933 DOI: 10.7554/elife.29677] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/22/2017] [Indexed: 12/18/2022] Open
Abstract
Local regulation of synaptic efficacy is thought to be important for proper networking of neurons and memory formation. Dysregulation of global translation influences long-term memory in mice, but the relevance of the regulation specific for local translation by RNA granules remains elusive. Here, we demonstrate roles of RNG105/caprin1 in long-term memory formation. RNG105 deletion in mice impaired synaptic strength and structural plasticity in hippocampal neurons. Furthermore, RNG105-deficient mice displayed unprecedentedly severe defects in long-term memory formation in spatial and contextual learning tasks. Genome-wide profiling of mRNA distribution in the hippocampus revealed an underlying mechanism: RNG105 deficiency impaired the asymmetric somato-dendritic localization of mRNAs. Particularly, RNG105 deficiency reduced the dendritic localization of mRNAs encoding regulators of AMPAR surface expression, which was consistent with attenuated homeostatic AMPAR scaling in dendrites and reduced synaptic strength. Thus, RNG105 has an essential role, as a key regulator of dendritic mRNA localization, in long-term memory formation. Messages pass from one nerve cell to the next across gaps called synapses. The first neuron releases chemical signals from the end of its long, thin nerve fiber. The second receives the message at receptors on branching structures known as dendrites. Each connection has a corresponding bump called a dendritic spine. As animals learn, these can grow larger, strengthening the connection. This is the basis of how memories form. To strengthen a synapse, the cell must transport the materials to the dendritic spine. The cell makes copies of the genetic instructions to strengthen the synapse in the form of messenger RNA (often shortened to mRNA). But, this happens in the body of the cell, a long way from the dendrites themselves. The mRNA travels from the cell body to the dendrites in collections of molecules referred to as ‘RNA granules’. One of the key components of the RNA granule system is a protein called RNG105/caprin1. Now, Nakayama, Ohashi et al. have engineered mice to delete the gene for RNG105/caprin1, revealing its effect on memory. Mice lacking RNG105/caprin1 struggled to make long-term memories. Unlike their normal counterparts, these mutant mice did not become accustomed to new environments or objects. They also found it more challenging to learn the position of a hidden platform in a water-based maze. Lastly, over time, the mutant mice forgot to be fearful of a dark chamber where they had received a small electric shock. Memories form in a part of the brain called the hippocampus and the dendritic spines in this region were smaller in mice lacking RNG105/caprin1. Furthermore, when the nerve cells from this part of the brain were grown in Petri dishes, they did not respond normally to stimulation. The dendritic spines of normal cells increased in size, but those on the cells lacking RNG105/caprin1 got smaller compared to normal cells. A closer look revealed that the distribution of mRNA in brain cells from mice lacking RNG105/caprin1 differed from that of normal mice. Some pieces of genetic information failed to make it from the cell body to the dendrites. This included mRNA involved in making regulators of a component of dendritic spines called the AMPA receptor. The AMPA receptor detects the chemical messenger, glutamate, and is crucial for memory formation. These findings further our understanding of long-term memory and open the way for future research into human disease. Mutations in RNA granule components, including RNG105/caprin1, have links to conditions such as amyotrophic lateral sclerosis (ALS) and autism spectrum disorder (ASD). Further investigation could reveal new targets for drug treatment.
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Affiliation(s)
- Kei Nakayama
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Okazaki Institute for Integrative Bioscience, Okazaki, Japan
| | - Rie Ohashi
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan
| | - Yo Shinoda
- Department of Applied Biological Science, Tokyo University of Science, Noda, Japan.,School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Akihiro Fujikawa
- Division of Molecular Neurobiology, National Institute for Basic Biology, Okazaki, Japan
| | - Shuji Shigenobu
- Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Akira Futatsugi
- Department of Basic Medical Science, Kobe City College of Nursing, Hyogo, Japan
| | - Masaharu Noda
- Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Division of Molecular Neurobiology, National Institute for Basic Biology, Okazaki, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Brain Science Institute, Wako, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Tokyo University of Science, Noda, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Nobuyuki Shiina
- Laboratory of Neuronal Cell Biology, National Institute for Basic Biology, Okazaki, Japan.,Department of Basic Biology, SOKENDAI, Okazaki, Japan.,Okazaki Institute for Integrative Bioscience, Okazaki, Japan
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88
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Gobbo F, Marchetti L, Jacob A, Pinto B, Binini N, Pecoraro Bisogni F, Alia C, Luin S, Caleo M, Fellin T, Cancedda L, Cattaneo A. Activity-dependent expression of Channelrhodopsin at neuronal synapses. Nat Commun 2017; 8:1629. [PMID: 29158498 PMCID: PMC5696361 DOI: 10.1038/s41467-017-01699-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 10/06/2017] [Indexed: 12/14/2022] Open
Abstract
Increasing evidence points to the importance of dendritic spines in the formation and allocation of memories, and alterations of spine number and physiology are associated to memory and cognitive disorders. Modifications of the activity of subsets of synapses are believed to be crucial for memory establishment. However, the development of a method to directly test this hypothesis, by selectively controlling the activity of potentiated spines, is currently lagging. Here we introduce a hybrid RNA/protein approach to regulate the expression of a light-sensitive membrane channel at activated synapses, enabling selective tagging of potentiated spines following the encoding of a novel context in the hippocampus. This approach can be used to map potentiated synapses in the brain and will make it possible to re-activate the neuron only at previously activated synapses, extending current neuron-tagging technologies in the investigation of memory processes.
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Affiliation(s)
- Francesco Gobbo
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy.,NEST, Scuola Normale Superiore, piazza San Silvestro 12, 56127, Pisa, Italy
| | - Laura Marchetti
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy.,NEST, Scuola Normale Superiore, piazza San Silvestro 12, 56127, Pisa, Italy.,Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, piazza San Silvestro 12, 56127, Pisa, Italy
| | - Ajesh Jacob
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy
| | - Bruno Pinto
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy.,Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
| | - Noemi Binini
- Optical Approaches to Brain Function Laboratory, Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genova, Italy
| | - Federico Pecoraro Bisogni
- Optical Approaches to Brain Function Laboratory, Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genova, Italy
| | - Claudia Alia
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy.,Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, via Moruzzi 1, 56124, Pisa, Italy
| | - Stefano Luin
- NEST, Scuola Normale Superiore, piazza San Silvestro 12, 56127, Pisa, Italy
| | - Matteo Caleo
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, via Moruzzi 1, 56124, Pisa, Italy
| | - Tommaso Fellin
- Optical Approaches to Brain Function Laboratory, Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genova, Italy
| | - Laura Cancedda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy.,Dulbecco Telethon Institute, via Varese 16b, 00185, Rome, Italy
| | - Antonino Cattaneo
- Bio@SNS, Scuola Normale Superiore, piazza dei Cavalieri 7, 56126, Pisa, Italy.
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89
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Kuzniewska B, Chojnacka M, Milek J, Dziembowska M. Preparation of polysomal fractions from mouse brain synaptoneurosomes and analysis of polysomal-bound mRNAs. J Neurosci Methods 2017; 293:226-233. [PMID: 28993203 DOI: 10.1016/j.jneumeth.2017.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/11/2017] [Accepted: 10/05/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND Here we describe a detailed, reliable protocol for isolation of polysomal fractions from mouse brain synaptoneurosomes. This method is an important tool to study local protein synthesis in neurons. NEW METHOD We combined rapid preparation of synaptoneurosomes by filtration with polysome profiling. We provide a detailed protocol highlighting difficulties and critical steps of: i) preparation of synaptoneurosomes; ii) polyribosome fractionation from synaptoneurosomes; iii) extraction of proteins and RNA from sucrose gradient fractions. RESULTS and Comparison with Existing Methods We fractionated polyribosomes from synaptoneurosomes and detected the association of Mmp9, Camk2a and Stx1B mRNA with polysomes in the unstimulated conditions. Synaptic stimulation led to increased levels of Mmp9 and Camk2a mRNA in the heavy polysomal fractions. We compared our protocol with existing methods CONCLUSIONS: We have developed a reliable, effective method to prepare polyribosomal fractions from synaptoneurosomes to study polyribosomal binding of mRNAs as an aspect of synaptic translation in vitro.
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Affiliation(s)
- Bozena Kuzniewska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Magdalena Chojnacka
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland; Laboratory of RNA Biology and Functional Genomics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106 Warsaw, Poland
| | - Jacek Milek
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Magdalena Dziembowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland.
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90
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The Long 3'UTR mRNA of CaMKII Is Essential for Translation-Dependent Plasticity of Spontaneous Release in Drosophila melanogaster. J Neurosci 2017; 37:10554-10566. [PMID: 28954869 DOI: 10.1523/jneurosci.1313-17.2017] [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: 05/09/2017] [Revised: 09/05/2017] [Accepted: 09/19/2017] [Indexed: 12/27/2022] Open
Abstract
A null mutation of the Drosophila calcium/calmodulin-dependent protein kinase II gene (CaMKII) was generated using homologous recombination. Null animals survive to larval and pupal stages due to a large maternal contribution of CaMKII mRNA, which consists of a short 3'-untranslated region (UTR) form lacking regulatory elements that guide local translation. The selective loss of the long 3'UTR mRNA in CaMKII-null larvae allows us to test its role in plasticity. Development and evoked function of the larval neuromuscular junction are surprisingly normal, but the resting rate of miniature excitatory junctional potentials (mEJPs) is significantly lower in CaMKII mutants. Mutants also lack the ability to increase mEJP rate in response to spaced depolarization, a type of activity-dependent plasticity shown to require both transcription and translation. Consistent with this, overexpression of miR-289 in wild-type animals blocks plasticity of spontaneous release. In addition to the defects in regulation of mEJP rate, CaMKII protein is largely lost from synapses in the mutant. All phenotypes are non-sex-specific and rescued by a fosmid containing the entire wild-type CaMKII locus, but only viability and CaMKII localization are rescued by genomic fosmids lacking the long 3'UTR. This suggests that synaptic CaMKII accumulates by two distinct mechanisms: local synthesis requiring the long 3'UTR form of CaMKII mRNA and a process that requires zygotic transcription of CaMKII mRNA. The origin of synaptic CaMKII also dictates its functionality. Locally translated CaMKII has a privileged role in regulation of spontaneous release, which cannot be fulfilled by synaptic CaMKII from the other pool.SIGNIFICANCE STATEMENT As a regulator of synaptic development and plasticity, CaMKII has important roles in both normal and pathological function of the nervous system. CaMKII shows high conservation between Drosophila and humans, underscoring the usefulness of Drosophila in modeling its function. Drosophila CaMKII-null mutants remain viable throughout development, enabling morphological and electrophysiological characterization. Although the structure of the synapse is normal, maternally contributed CaMKII does not localize to synapses. Zygotic production of CaMKII mRNA with a long 3'-untranslated region is necessary for modulating spontaneous neurotransmission in an activity-dependent manner, but not for viability. These data argue that regulation of CaMKII localization and levels by local transcriptional processes is conserved. This is the first demonstration of distinct functions for Drosophila CaMKII mRNA variants.
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91
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Sambandan S, Akbalik G, Kochen L, Rinne J, Kahlstatt J, Glock C, Tushev G, Alvarez-Castelao B, Heckel A, Schuman EM. Activity-dependent spatially localized miRNA maturation in neuronal dendrites. Science 2017; 355:634-637. [PMID: 28183980 DOI: 10.1126/science.aaf8995] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 11/17/2016] [Accepted: 01/05/2017] [Indexed: 12/22/2022]
Abstract
MicroRNAs (miRNAs) regulate gene expression by binding to target messenger RNAs (mRNAs) and preventing their translation. In general, the number of potential mRNA targets in a cell is much greater than the miRNA copy number, complicating high-fidelity miRNA-target interactions. We developed an inducible fluorescent probe to explore whether the maturation of a miRNA could be regulated in space and time in neurons. A precursor miRNA (pre-miRNA) probe exhibited an activity-dependent increase in fluorescence, suggesting the stimulation of miRNA maturation. Single-synapse stimulation resulted in a local maturation of miRNA that was associated with a spatially restricted reduction in the protein synthesis of a target mRNA. Thus, the spatially and temporally regulated maturation of pre-miRNAs can be used to increase the precision and robustness of miRNA-mediated translational repression.
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Affiliation(s)
- Sivakumar Sambandan
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany
| | - Güney Akbalik
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany
| | - Lisa Kochen
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany
| | - Jennifer Rinne
- Institute for Organic Chemistry and Chemical Biology, Goethe University, 60438 Frankfurt, Germany
| | - Josefine Kahlstatt
- Institute for Organic Chemistry and Chemical Biology, Goethe University, 60438 Frankfurt, Germany
| | - Caspar Glock
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany
| | - Georgi Tushev
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany
| | | | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology, Goethe University, 60438 Frankfurt, Germany. .,Cluster of Excellence "Macromolecular Complexes in Action," Goethe University, 60438 Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Max-von-Laue Straße 4, 60438 Frankfurt, Germany. .,Cluster of Excellence "Macromolecular Complexes in Action," Goethe University, 60438 Frankfurt, Germany
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92
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Schaefer N, Rotermund C, Blumrich EM, Lourenco MV, Joshi P, Hegemann RU, Jamwal S, Ali N, García Romero EM, Sharma S, Ghosh S, Sinha JK, Loke H, Jain V, Lepeta K, Salamian A, Sharma M, Golpich M, Nawrotek K, Paidi RK, Shahidzadeh SM, Piermartiri T, Amini E, Pastor V, Wilson Y, Adeniyi PA, Datusalia AK, Vafadari B, Saini V, Suárez-Pozos E, Kushwah N, Fontanet P, Turner AJ. The malleable brain: plasticity of neural circuits and behavior - a review from students to students. J Neurochem 2017. [PMID: 28632905 DOI: 10.1111/jnc.14107] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One of the most intriguing features of the brain is its ability to be malleable, allowing it to adapt continually to changes in the environment. Specific neuronal activity patterns drive long-lasting increases or decreases in the strength of synaptic connections, referred to as long-term potentiation and long-term depression, respectively. Such phenomena have been described in a variety of model organisms, which are used to study molecular, structural, and functional aspects of synaptic plasticity. This review originated from the first International Society for Neurochemistry (ISN) and Journal of Neurochemistry (JNC) Flagship School held in Alpbach, Austria (Sep 2016), and will use its curriculum and discussions as a framework to review some of the current knowledge in the field of synaptic plasticity. First, we describe the role of plasticity during development and the persistent changes of neural circuitry occurring when sensory input is altered during critical developmental stages. We then outline the signaling cascades resulting in the synthesis of new plasticity-related proteins, which ultimately enable sustained changes in synaptic strength. Going beyond the traditional understanding of synaptic plasticity conceptualized by long-term potentiation and long-term depression, we discuss system-wide modifications and recently unveiled homeostatic mechanisms, such as synaptic scaling. Finally, we describe the neural circuits and synaptic plasticity mechanisms driving associative memory and motor learning. Evidence summarized in this review provides a current view of synaptic plasticity in its various forms, offers new insights into the underlying mechanisms and behavioral relevance, and provides directions for future research in the field of synaptic plasticity. Read the Editorial Highlight for this article on page 788. Cover Image for this issue: doi: 10.1111/jnc.13815.
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Affiliation(s)
- Natascha Schaefer
- Institute for Clinical Neurobiology, Julius-Maximilians-University of Wuerzburg, Würzburg, Germany
| | - Carola Rotermund
- German Center of Neurodegenerative Diseases, University of Tuebingen, Tuebingen, Germany
| | - Eva-Maria Blumrich
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, Bremen, Germany.,Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
| | - Mychael V Lourenco
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pooja Joshi
- Inserm UMR 1141, Robert Debre Hospital, Paris, France
| | - Regina U Hegemann
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Sumit Jamwal
- Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Nilufar Ali
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | | | - Sorabh Sharma
- Neuropharmacology Division, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Shampa Ghosh
- National Institute of Nutrition (NIN), Indian Council of Medical Research (ICMR), Tarnaka, Hyderabad, India
| | - Jitendra K Sinha
- National Institute of Nutrition (NIN), Indian Council of Medical Research (ICMR), Tarnaka, Hyderabad, India
| | - Hannah Loke
- Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Molecular and Translational Science, Monash University, Melbourne, Victoria, Australia
| | - Vishal Jain
- Defence Institute of Physiology and Allied Sciences, Delhi, India
| | - Katarzyna Lepeta
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Ahmad Salamian
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Mahima Sharma
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mojtaba Golpich
- Department of Medicine, University Kebangsaan Malaysia Medical Centre (HUKM), Cheras, Kuala Lumpur, Malaysia
| | - Katarzyna Nawrotek
- Department of Process Thermodynamics, Faculty of Process and Environmental Engineering, Lodz University of Technology, Lodz, Poland
| | - Ramesh K Paidi
- CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sheila M Shahidzadeh
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York, USA
| | - Tetsade Piermartiri
- Programa de Pós-Graduação em Neurociências, Universidade Federal de Santa Catarina (UFSC), Florianópolis, Brazil
| | - Elham Amini
- Department of Medicine, University Kebangsaan Malaysia Medical Centre (HUKM), Cheras, Kuala Lumpur, Malaysia
| | - Veronica Pastor
- Instituto de Biología Celular y Neurociencia Prof. Eduardo De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yvette Wilson
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia
| | - Philip A Adeniyi
- Cell Biology and Neurotoxicity Unit, Department of Anatomy, College of Medicine and Health Sciences, Afe Babalola University, Ado - Ekiti, Ekiti State, Nigeria
| | | | - Benham Vafadari
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Vedangana Saini
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Edna Suárez-Pozos
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Toxicología, México
| | - Neetu Kushwah
- Defence Institute of Physiology and Allied Sciences, Delhi, India
| | - Paula Fontanet
- Division of Molecular and Cellular Neuroscience, Institute of Cellular Biology and Neuroscience (IBCN), CONICET-UBA, School of Medicine, Buenos Aires, Argentina
| | - Anthony J Turner
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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93
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Wong HHW, Lin JQ, Ströhl F, Roque CG, Cioni JM, Cagnetta R, Turner-Bridger B, Laine RF, Harris WA, Kaminski CF, Holt CE. RNA Docking and Local Translation Regulate Site-Specific Axon Remodeling In Vivo. Neuron 2017; 95:852-868.e8. [PMID: 28781168 PMCID: PMC5563073 DOI: 10.1016/j.neuron.2017.07.016] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 06/09/2017] [Accepted: 07/14/2017] [Indexed: 12/03/2022]
Abstract
Nascent proteins can be positioned rapidly at precise subcellular locations by local protein synthesis (LPS) to facilitate localized growth responses. Axon arbor architecture, a major determinant of synaptic connectivity, is shaped by localized growth responses, but it is unknown whether LPS influences these responses in vivo. Using high-resolution live imaging, we examined the spatiotemporal dynamics of RNA and LPS in retinal axons during arborization in vivo. Endogenous RNA tracking reveals that RNA granules dock at sites of branch emergence and invade stabilized branches. Live translation reporter analysis reveals that de novo β-actin hotspots colocalize with docked RNA granules at the bases and tips of new branches. Inhibition of axonal β-actin mRNA translation disrupts arbor dynamics primarily by reducing new branch emergence and leads to impoverished terminal arbors. The results demonstrate a requirement for LPS in building arbor complexity and suggest a key role for pre-synaptic LPS in assembling neural circuits. Tracking endogenous RNA shows that RNA docking predicts axon branch emergence in vivo Axon arbor complexity in vivo depends on local protein synthesis Axonal β-actin synthesis regulates branching by increased branch initiation Live imaging reveals de novo synthesis of β-actin hotspots during branch formation
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Affiliation(s)
- Hovy Ho-Wai Wong
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Julie Qiaojin Lin
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Florian Ströhl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Cláudio Gouveia Roque
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Jean-Michel Cioni
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Roberta Cagnetta
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Benita Turner-Bridger
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Romain F Laine
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - William A Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
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94
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95
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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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96
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Nascent Proteome Remodeling following Homeostatic Scaling at Hippocampal Synapses. Neuron 2017; 92:358-371. [PMID: 27764671 PMCID: PMC5078608 DOI: 10.1016/j.neuron.2016.09.058] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/16/2016] [Accepted: 09/27/2016] [Indexed: 12/16/2022]
Abstract
Homeostatic scaling adjusts the strength of synaptic connections up or down in response to large changes in input. To identify the landscape of proteomic changes that contribute to opposing forms of homeostatic plasticity, we examined the plasticity-induced changes in the newly synthesized proteome. Cultured rat hippocampal neurons underwent homeostatic up-scaling or down-scaling. We used BONCAT (bio-orthogonal non-canonical amino acid tagging) to metabolically label, capture, and identify newly synthesized proteins, detecting and analyzing 5,940 newly synthesized proteins using mass spectrometry and label-free quantitation. Neither up- nor down-scaling produced changes in the number of different proteins translated. Rather, up- and down-scaling elicited opposing translational regulation of several molecular pathways, producing targeted adjustments in the proteome. We discovered ∼300 differentially regulated proteins involved in neurite outgrowth, axon guidance, filopodia assembly, excitatory synapses, and glutamate receptor complexes. We also identified differentially regulated proteins that are associated with multiple diseases, including schizophrenia, epilepsy, and Parkinson's disease.
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97
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Spaulding EL, Burgess RW. Accumulating Evidence for Axonal Translation in Neuronal Homeostasis. Front Neurosci 2017; 11:312. [PMID: 28620277 PMCID: PMC5450000 DOI: 10.3389/fnins.2017.00312] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022] Open
Abstract
The specialized structure of the neuron requires that homeostasis is sustained over the meter or more that may separate a cell body from its axonal terminus. Given this impressive distance and an axonal volume that is many times that of the cell body, how is such a compartment grown during development, re-grown after injury, and maintained throughout adulthood? While early answers to these questions focused on the local environment or the cell soma as supplying the needs of the axon, it is now well-established that the axon has some unique needs that can only be met from within. Decades of research have revealed local translation as an indispensable mechanism of axonal homeostasis during development and regeneration in both invertebrates and vertebrates. In contrast, the extent to which the adult, mammalian axonal proteome is maintained through local translation remains unclear and controversial. This mini-review aims to highlight important experiments that have helped to shape the field of axonal translation, to discuss conceptual arguments and recent evidence that supports local translation as important to the maintenance of adult axons, and to suggest experimental approaches that have the potential to further illuminate the role of axonal translation in neuronal homeostasis.
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Affiliation(s)
- Emily L Spaulding
- The Jackson LaboratoryBar Harbor, ME, United States.,Graduate School of Biomedical Sciences and Engineering, University of MaineOrono, ME, United States
| | - Robert W Burgess
- The Jackson LaboratoryBar Harbor, ME, United States.,Graduate School of Biomedical Sciences and Engineering, University of MaineOrono, ME, United States
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98
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Sudhakaran IP, Ramaswami M. Long-term memory consolidation: The role of RNA-binding proteins with prion-like domains. RNA Biol 2017; 14:568-586. [PMID: 27726526 PMCID: PMC5449092 DOI: 10.1080/15476286.2016.1244588] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/07/2016] [Accepted: 09/29/2016] [Indexed: 12/23/2022] Open
Abstract
Long-term and short-term memories differ primarily in the duration of their retention. At a molecular level, long-term memory (LTM) is distinguished from short-term memory (STM) by its requirement for new gene expression. In addition to transcription (nuclear gene expression) the translation of stored mRNAs is necessary for LTM formation. The mechanisms and functions for temporal and spatial regulation of mRNAs required for LTM is a major contemporary problem, of interest from molecular, cell biological, neurobiological and clinical perspectives. This review discusses primary evidence in support for translational regulatory events involved in LTM and a model in which different phases of translation underlie distinct phases of consolidation of memories. However, it focuses largely on mechanisms of memory persistence and the role of prion-like domains in this defining aspect of long-term memory. We consider primary evidence for the concept that Cytoplasmic Polyadenylation Element Binding (CPEB) protein enables the persistence of formed memories by transforming in prion-like manner from a soluble monomeric state to a self-perpetuating and persistent polymeric translationally active state required for maintaining persistent synaptic plasticity. We further discuss prion-like domains prevalent on several other RNA-binding proteins involved in neuronal translational control underlying LTM. Growing evidence indicates that such RNA regulatory proteins are components of mRNP (RiboNucleoProtein) granules. In these proteins, prion-like domains, being intrinsically disordered, could mediate weak transient interactions that allow the assembly of RNP granules, a source of silenced mRNAs whose translation is necessary for LTM. We consider the structural bases for RNA granules formation as well as functions of disordered domains and discuss how these complicate the interpretation of existing experimental data relevant to general mechanisms by which prion-domain containing RBPs function in synapse specific plasticity underlying LTM.
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Affiliation(s)
- Indulekha P. Sudhakaran
- National Center for Biological Sciences, TIFR, Bangalore, India
- Manipal University, Manipal, India
| | - Mani Ramaswami
- National Center for Biological Sciences, TIFR, Bangalore, India
- School of Genetics and Microbiology and School of Natural Sciences, Smurfit Institute of Genetics and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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99
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Rangaraju V, Tom Dieck S, Schuman EM. Local translation in neuronal compartments: how local is local? EMBO Rep 2017; 18:693-711. [PMID: 28404606 DOI: 10.15252/embr.201744045] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 12/18/2022] Open
Abstract
Efficient neuronal function depends on the continued modulation of the local neuronal proteome. Local protein synthesis plays a central role in tuning the neuronal proteome at specific neuronal regions. Various aspects of translation such as the localization of translational machinery, spatial spread of the newly translated proteins, and their site of action are carried out in specialized neuronal subcompartments to result in a localized functional outcome. In this review, we focus on the various aspects of these local translation compartments such as size, biochemical and organelle composition, structural boundaries, and temporal dynamics. We also discuss the apparent absence of definitive components of translation in these local compartments and the emerging state-of-the-art tools that could help dissecting these conundrums in greater detail in the future.
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Affiliation(s)
- Vidhya Rangaraju
- 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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100
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Li F, Tian X, Zhan X, Wang B, Ding M, Pang H. Clathrin-Dependent Uptake of Paraquat into SH-SY5Y Cells and Its Internalization into Different Subcellular Compartments. Neurotox Res 2017; 32:204-217. [PMID: 28303546 DOI: 10.1007/s12640-017-9722-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 02/19/2017] [Accepted: 03/07/2017] [Indexed: 01/09/2023]
Abstract
The herbicide paraquat (PQ) is an exogenous toxin that allows the selective activation of dopaminergic neurons in the mesencephalon to induce injury and also causes its apoptosis in vitro. However, uptake mechanisms between PQ and neurons remain elusive. To address this issue, we undertook a study of PQ endocytosis in a dopaminergic SH-SY5Y cell line as well as explored the subsequent subcellular location and potential functional analysis of PQ. The PQ was found to bind the SH-SY5Y cell membrane and then became internalized via a clathrin-dependent pathway. PQ was internalized by many subcellular organelles in a time- and dose-dependent manner. Interestingly, the taken up PQ and secretogranin III (SCG3), which became dysregulated with PQ treatment that induced SH-SY5Y apoptosis in our previous study, colocalized in cytoplasmic vesicles. Taken together, our findings indicate that PQ is endocytosed by SH-SY5Y cells and that its multiple, subcellular localizations indicate PQ may potentially be involved in subcellular-level functions. More importantly, PQ distributing preferentially into SCG3-positive vesicles demonstrates its selective targeting which may affect SCG3 and cargoes carried by SCG3-positive vesicles. Therefore, it is reasonable to infer that PQ toxic insults may potentially interfere with neurotransmitter storage and transport associated with secretory granules.
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Affiliation(s)
- Fengrui Li
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.,Department of Forensic Medicine, Baotou Medical University, Baotou, People's Republic of China
| | - Xiaofei Tian
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.,Department of Forensic Medicine, Hebei North University, Zhangjiakou, People's Republic of China
| | - Xiaoni Zhan
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China
| | - Baojie Wang
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China
| | - Mei Ding
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China
| | - Hao Pang
- School of Forensic Medicine, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
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