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Li LY, Imai A, Izumi H, Inoue R, Koshidaka Y, Takao K, Mori H, Yoshida T. Differential contribution of canonical and noncanonical NLGN3 pathways to early social development and memory performance. Mol Brain 2024; 17:16. [PMID: 38475840 PMCID: PMC10935922 DOI: 10.1186/s13041-024-01087-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Neuroligin (NLGN) 3 is a postsynaptic cell adhesion protein organizing synapse formation through two different types of transsynaptic interactions, canonical interaction with neurexins (NRXNs) and a recently identified noncanonical interaction with protein tyrosine phosphatase (PTP) δ. Although, NLGN3 gene is known as a risk gene for neurodevelopmental disorders such as autism spectrum disorder (ASD) and intellectual disability (ID), the pathogenic contribution of the canonical NLGN3-NRXN and noncanonical NLGN3-PTPδ pathways to these disorders remains elusive. In this study, we utilized Nlgn3 mutant mice selectively lacking the interaction with either NRXNs or PTPδ and investigated their social and memory performance. Neither Nlgn3 mutants showed any social cognitive deficiency in the social novelty recognition test. However, the Nlgn3 mutant mice lacking the PTPδ pathway exhibited significant decline in the social conditioned place preference (sCPP) at the juvenile stage, suggesting the involvement of the NLGN3-PTPδ pathway in the regulation of social motivation and reward. In terms of learning and memory, disrupting the canonical NRXN pathway attenuated contextual fear conditioning while disrupting the noncanonical NLGN3-PTPδ pathway enhanced it. Furthermore, disruption of the NLGN3-PTPδ pathway negatively affected the remote spatial reference memory in the Barnes maze test. These findings highlight the differential contributions of the canonical NLGN3-NRXN and noncanonical NLGN3-PTPδ synaptogenic pathways to the regulation of higher order brain functions associated with ASD and ID.
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Affiliation(s)
- Lin-Yu Li
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Ayako Imai
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan
| | - Hironori Izumi
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan
| | - Ran Inoue
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan
| | - Yumie Koshidaka
- Division of Experimental Animal Resource and Development, Life Science Research Center, University of Toyama, Toyama, 930-0194, Japan
| | - Keizo Takao
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan
- Division of Experimental Animal Resource and Development, Life Science Research Center, University of Toyama, Toyama, 930-0194, Japan
- Department of Behavioral Physiology, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, 930-0194, Japan.
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Benner O, Cast TP, Minamide LS, Lenninger Z, Bamburg JR, Chanda S. Multiple N-linked glycosylation sites critically modulate the synaptic abundance of neuroligin isoforms. J Biol Chem 2023; 299:105361. [PMID: 37865312 PMCID: PMC10679506 DOI: 10.1016/j.jbc.2023.105361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/23/2023] Open
Abstract
In recent years, elegant glycomic and glycoproteomic approaches have revealed an intricate glycosylation profile of mammalian brain with enormous spatial and temporal diversities. Nevertheless, at a cellular level, it is unclear how these post-translational modifications affect various proteins to influence crucial neuronal properties. Here, we have investigated the impact of N-linked glycosylation on neuroligins (NLGNs), a class of cell-adhesion molecules that play instructive roles in synapse organization. We found that endogenous NLGN proteins are differentially glycosylated across several regions of murine brain in a sex-independent but isoform-dependent manner. In both rodent primary neurons derived from brain sections and human neurons differentiated from stem cells, all NLGN variants were highly enriched with multiple N-glycan subtypes, which cumulatively ensured their efficient trafficking to the cell surface. Removal of these N-glycosylation residues only had a moderate effect on NLGNs' stability or expression levels but particularly enhanced their retention at the endoplasmic reticulum. As a result, the glycosylation-deficient NLGNs exhibited considerable impairments in their dendritic distribution and postsynaptic accumulation, which in turn, virtually eliminated their ability to recruit presynaptic terminals and significantly reduced NLGN overexpression-induced assemblies of both glutamatergic and GABAergic synapse structures. Therefore, our results highlight an essential mechanistic contribution of N-linked glycosylations in facilitating the appropriate secretory transport of a major synaptic cell-adhesion molecule and promoting its cellular function in neurons.
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Affiliation(s)
- Orion Benner
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Thomas P Cast
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Laurie S Minamide
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA
| | - Zephyr Lenninger
- Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA
| | - James R Bamburg
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA; Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA; Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Soham Chanda
- Biochemistry & Molecular Biology, Colorado State University, Fort Collins, USA; Molecular, Cellular & Integrated Neurosciences, Colorado State University, Fort Collins, Colorado, USA; Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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de Jong-Bolm D, Sadeghi M, Bogaciu CA, Bao G, Klaehn G, Hoff M, Mittelmeier L, Basmanav FB, Opazo F, Noé F, Rizzoli SO. Protein nanobarcodes enable single-step multiplexed fluorescence imaging. PLoS Biol 2023; 21:e3002427. [PMID: 38079451 PMCID: PMC10735187 DOI: 10.1371/journal.pbio.3002427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/21/2023] [Accepted: 11/13/2023] [Indexed: 12/23/2023] Open
Abstract
Multiplexed cellular imaging typically relies on the sequential application of detection probes, as antibodies or DNA barcodes, which is complex and time-consuming. To address this, we developed here protein nanobarcodes, composed of combinations of epitopes recognized by specific sets of nanobodies. The nanobarcodes are read in a single imaging step, relying on nanobodies conjugated to distinct fluorophores, which enables a precise analysis of large numbers of protein combinations. Fluorescence images from nanobarcodes were used as input images for a deep neural network, which was able to identify proteins with high precision. We thus present an efficient and straightforward protein identification method, which is applicable to relatively complex biological assays. We demonstrate this by a multicell competition assay, in which we successfully used our nanobarcoded proteins together with neurexin and neuroligin isoforms, thereby testing the preferred binding combinations of multiple isoforms, in parallel.
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Affiliation(s)
- Daniëlle de Jong-Bolm
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
| | - Mohsen Sadeghi
- Department of Mathematics and Computer Science, Free University of Berlin, Berlin, Germany
| | - Cristian A. Bogaciu
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
| | - Guobin Bao
- Institute of Pharmacology and Toxicology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Gabriele Klaehn
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
| | - Merle Hoff
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
| | - Lucas Mittelmeier
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
| | - F. Buket Basmanav
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
- Campus Laboratory for Advanced Imaging, Microscopy and Spectroscopy, University of Göttingen, Göttingen, Germany
| | - Felipe Opazo
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), University of Göttingen Medical Center, Göttingen, Germany
- NanoTag Biotechnologies GmbH, Göttingen, Germany
| | - Frank Noé
- Department of Mathematics and Computer Science, Free University of Berlin, Berlin, Germany
- Department of Physics, Free University of Technology, Berlin, Germany
- Department of Chemistry, Rice University, Houston, Texas, United States of America
- Microsoft Research AI4Science, Berlin, Germany
| | - Silvio O. Rizzoli
- Department of Neuro- and Sensory physiology, University of Göttingen Medical Center, Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Göttingen, Germany
- NanoTag Biotechnologies GmbH, Göttingen, Germany
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Hale WD, Südhof TC, Huganir RL. Engineered adhesion molecules drive synapse organization. Proc Natl Acad Sci U S A 2023; 120:e2215905120. [PMID: 36638214 PMCID: PMC9934208 DOI: 10.1073/pnas.2215905120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/04/2022] [Indexed: 01/15/2023] Open
Abstract
In multicellular organisms, cell-adhesion molecules connect cells into tissues and mediate intercellular signaling between these cells. In vertebrate brains, synaptic cell-adhesion molecules (SAMs) guide the formation, specification, and plasticity of synapses. Some SAMs, when overexpressed in cultured neurons or in heterologous cells co-cultured with neurons, drive formation of synaptic specializations onto the overexpressing cells. However, genetic deletion of the same SAMs from neurons often has no effect on synapse numbers, but frequently severely impairs synaptic transmission, suggesting that most SAMs control the function and plasticity of synapses (i.e., organize synapses) instead of driving their initial establishment (i.e., make synapses). Since few SAMs were identified that mediate initial synapse formation, it is difficult to develop methods that enable experimental control of synaptic connections by targeted expression of these SAMs. To overcome this difficulty, we engineered novel SAMs from bacterial proteins with no eukaryotic homologues that drive synapse formation. We named these engineered adhesion proteins "Barnoligin" and "Starexin" because they were assembled from parts of Barnase and Neuroligin-1 or of Barstar and Neurexin3β, respectively. Barnoligin and Starexin robustly induce the formation of synaptic specializations in a specific and directional manner in cultured neurons. Synapse formation by Barnoligin and Starexin requires both their extracellular Barnase- and Barstar-derived interaction domains and their Neuroligin- and Neurexin-derived intracellular signaling domains. Our findings support a model of synapse formation whereby trans-synaptic interactions by SAMs drive synapse organization via adhesive interactions that activate signaling cascades.
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Affiliation(s)
- W. Dylan Hale
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Richard L. Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
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5
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Cortés E, Pak JS, Özkan E. Structure and evolution of neuronal wiring receptors and ligands. Dev Dyn 2023; 252:27-60. [PMID: 35727136 PMCID: PMC10084454 DOI: 10.1002/dvdy.512] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 01/04/2023] Open
Abstract
One of the fundamental properties of a neuronal circuit is the map of its connections. The cellular and developmental processes that allow for the growth of axons and dendrites, selection of synaptic targets, and formation of functional synapses use neuronal surface receptors and their interactions with other surface receptors, secreted ligands, and matrix molecules. Spatiotemporal regulation of the expression of these receptors and cues allows for specificity in the developmental pathways that wire stereotyped circuits. The families of molecules controlling axon guidance and synapse formation are generally conserved across animals, with some important exceptions, which have consequences for neuronal connectivity. Here, we summarize the distribution of such molecules across multiple taxa, with a focus on model organisms, evolutionary processes that led to the multitude of such molecules, and functional consequences for the diversification or loss of these receptors.
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Affiliation(s)
- Elena Cortés
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
| | - Joseph S Pak
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
| | - Engin Özkan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
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Uchigashima M, Hayashi Y, Futai K. Regulation of Presynaptic Release Machinery by Cell Adhesion Molecules. ADVANCES IN NEUROBIOLOGY 2023; 33:333-356. [PMID: 37615873 DOI: 10.1007/978-3-031-34229-5_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
The synapse is a highly specialized asymmetric structure that transmits and stores information in the brain. The size of pre- and postsynaptic structures and function is well coordinated at the individual synapse level. For example, large postsynaptic dendritic spines have a larger postsynaptic density with higher α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) number on their surface, while juxtaposing presynaptic terminals have a larger active zone and higher release probability. This indicates that pre- and postsynaptic domains bidirectionally communicate to coordinate assembly of specific molecules on both sides of the synaptic cleft. Cell adhesion molecules (CAMs) that localize at synapses form transsynaptic protein interactions across the synaptic cleft and play important roles in synapse formation and regulation. The extracellular domain of CAMs is essential for specific synapse formation and function. In contrast, the intracellular domain is necessary for binding with synaptic molecules and signal transduction. Therefore, CAMs play an essential role on synapse function and structure. In fact, ample evidence indicates that transsynaptic CAMs instruct and modulate functions at presynaptic sites. This chapter focuses on transsynaptic protein interactions that regulate presynaptic functions emphasizing the role of neuronal CAMs and the intracellular mechanism of their regulation.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Cellular Neuropathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Yasunori Hayashi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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Boxer EE, Aoto J. Neurexins and their ligands at inhibitory synapses. Front Synaptic Neurosci 2022; 14:1087238. [PMID: 36618530 PMCID: PMC9812575 DOI: 10.3389/fnsyn.2022.1087238] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Since the discovery of neurexins (Nrxns) as essential and evolutionarily conserved synaptic adhesion molecules, focus has largely centered on their functional contributions to glutamatergic synapses. Recently, significant advances to our understanding of neurexin function at GABAergic synapses have revealed that neurexins can play pleiotropic roles in regulating inhibitory synapse maintenance and function in a brain-region and synapse-specific manner. GABAergic neurons are incredibly diverse, exhibiting distinct synaptic properties, sites of innervation, neuromodulation, and plasticity. Different classes of GABAergic neurons often express distinct repertoires of Nrxn isoforms that exhibit differential alternative exon usage. Further, Nrxn ligands can be differentially expressed and can display synapse-specific localization patterns, which may contribute to the formation of a complex trans-synaptic molecular code that establishes the properties of inhibitory synapse function and properties of local circuitry. In this review, we will discuss how Nrxns and their ligands sculpt synaptic inhibition in a brain-region, cell-type and synapse-specific manner.
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Affiliation(s)
| | - Jason Aoto
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Denver, CO, United States
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Neurexin-β Mediates the Synaptogenic Activity of Amyloid Precursor Protein. J Neurosci 2022; 42:8936-8947. [PMID: 36261284 PMCID: PMC9732828 DOI: 10.1523/jneurosci.0511-21.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 09/13/2022] [Accepted: 10/12/2022] [Indexed: 01/05/2023] Open
Abstract
In addition to its role in Alzheimer's disease, amyloid precursor protein (APP) has physiological roles in synapse development and function. APP induces presynaptic differentiation when presented to axons, but the mechanism is unknown. Here we show that APP binds neurexin to mediate this synaptogenic activity. APP specifically binds β not α neurexins modulated by splice site 4. Binding to neurexin heparan sulfate glycan and LNS protein domains is required for high-affinity interaction and for full-length APP to recruit axonal neurexin. The synaptogenic activity of APP is abolished by triple knockdown of neurexins in hippocampal neurons pooled from male and female rats. Based on these and previous results, our model is that a dendritic-axonal trans dimer of full-length APP binds to axonal neurexin-β to promote synaptic differentiation and function. Furthermore, soluble sAPPs also bind neurexin-β and inhibit its interaction with neuroligin-1, raising the possibility that disruption of neurexin function by altered levels of full-length APP and its cleavage products may contribute to early synaptic deficits in Alzheimer's disease.SIGNIFICANCE STATEMENT The prevailing model for the basis of Alzheimer's disease is the amyloid cascade triggered by altered cleavage of amyloid precursor protein (APP). APP also has physiological roles at the synapse, but the molecular basis for its synaptic functions is not well understood. Here, we show that APP binds the presynaptic organizing protein neurexin-β and that neurexin is essential for the synaptogenic activity of APP. Furthermore, soluble APP forms generated by APP cleavage also bind neurexin-β and can block interaction with transmembrane synaptogenic ligands of neurexin. These findings reveal a role for neurexin-APP interaction in synapse development and raise the possibility that disruptions of neurexin function may contribute to synaptic and cognitive deficits in the critical early stage of Alzheimer's disease.
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Liu X, Hua F, Yang D, Lin Y, Zhang L, Ying J, Sheng H, Wang X. Roles of neuroligins in central nervous system development: focus on glial neuroligins and neuron neuroligins. Lab Invest 2022; 20:418. [PMID: 36088343 PMCID: PMC9463862 DOI: 10.1186/s12967-022-03625-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/01/2022] [Indexed: 11/10/2022]
Abstract
Neuroligins are postsynaptic cell adhesion molecules that are relevant to many neurodevelopmental disorders. They are differentially enriched at the postsynapse and interact with their presynaptic ligands, neurexins, whose differential binding to neuroligins has been shown to regulate synaptogenesis, transmission, and other synaptic properties. The proper functioning of functional networks in the brain depends on the proper connection between neuronal synapses. Impaired synaptogenesis or synaptic transmission results in synaptic dysfunction, and these synaptic pathologies are the basis for many neurodevelopmental disorders. Deletions or mutations in the neuroligins genes have been found in patients with both autism and schizophrenia. It is because of the important role of neuroligins in synaptic connectivity and synaptic dysfunction that studies on neuroligins in the past have mainly focused on their expression in neurons. As studies on the expression of genes specific to various cells of the central nervous system deepened, neuroligins were found to be expressed in non-neuronal cells as well. In the central nervous system, glial cells are the most representative non-neuronal cells, which can also express neuroligins in large amounts, especially astrocytes and oligodendrocytes, and they are involved in the regulation of synaptic function, as are neuronal neuroligins. This review examines the mechanisms of neuron neuroligins and non-neuronal neuroligins in the central nervous system and also discusses the important role of neuroligins in the development of the central nervous system and neurodevelopmental disorders from the perspective of neuronal neuroligins and glial neuroligins.
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Nozawa K, Sogabe T, Hayashi A, Motohashi J, Miura E, Arai I, Yuzaki M. In vivo nanoscopic landscape of neurexin ligands underlying anterograde synapse specification. Neuron 2022; 110:3168-3185.e8. [PMID: 36007521 DOI: 10.1016/j.neuron.2022.07.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 05/04/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022]
Abstract
Excitatory synapses are formed and matured by the cooperative actions of synaptic organizers, such as neurexins (Nrxns), neuroligins (Nlgns), LRRTMs, and Cbln1. Recent super-resolution nanoscopy developments have revealed that many synaptic organizers, as well as glutamate receptors and glutamate release machinery, exist as nanoclusters within synapses. However, it is unclear how such nanodomains interact with each other to organize excitatory synapses in vivo. By applying X10 expansion microscopy to epitope tag knockin mice, we found that Cbln1, Nlgn1, and LRRTM1, which share Nrxn as a common presynaptic receptor, form overlapping or separate nanodomains depending on Nrxn with or without a sequence encoded by splice site 4. The size and position of glutamate receptor nanodomains of GluD1, NMDA, and AMPA receptors were regulated by Cbln1, Nlgn1, and LRRTM1 nanodomains, respectively. These findings indicate that Nrxns anterogradely regulate the postsynaptic nanoscopic architecture of glutamate receptors through competition and coordination of Nrxn ligands.
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Affiliation(s)
- Kazuya Nozawa
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Taku Sogabe
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Ayumi Hayashi
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Junko Motohashi
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Eriko Miura
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Itaru Arai
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan.
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11
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Boxer EE, Seng C, Lukacsovich D, Kim J, Schwartz S, Kennedy MJ, Földy C, Aoto J. Neurexin-3 defines synapse- and sex-dependent diversity of GABAergic inhibition in ventral subiculum. Cell Rep 2021; 37:110098. [PMID: 34879268 PMCID: PMC8763380 DOI: 10.1016/j.celrep.2021.110098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/09/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022] Open
Abstract
Ventral subiculum (vSUB) is integral to the regulation of stress and reward; however, the intrinsic connectivity and synaptic properties of the inhibitory local circuit are poorly understood. Neurexin-3 (Nrxn3) is highly expressed in hippocampal inhibitory neurons, but its function at inhibitory synapses has remained elusive. Using slice electrophysiology, imaging, and single-cell RNA sequencing, we identify multiple roles for Nrxn3 at GABAergic parvalbumin (PV) interneuron synapses made onto vSUB regular-spiking (RS) and burst-spiking (BS) principal neurons. Surprisingly, we find that intrinsic connectivity of vSUB and synaptic function of Nrxn3 in vSUB are sexually dimorphic. We reveal that PVs make preferential contact with RS neurons in male mice, but BS neurons in female mice. Furthermore, we determine that despite comparable Nrxn3 isoform expression in male and female PV neurons, Nrxn3 knockout impairs synapse density, postsynaptic strength, and inhibitory postsynaptic current (IPSC) amplitude at PV-RS synapses in males, but enhances presynaptic release and IPSC amplitude in females.
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Affiliation(s)
- Emma E Boxer
- University of Colorado Anschutz, Department of Pharmacology, Aurora, CO 80045, USA; Neuroscience Graduate Program, University of Colorado Anschutz, Aurora, CO 80045, USA
| | - Charlotte Seng
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - JungMin Kim
- University of Colorado Anschutz, Department of Pharmacology, Aurora, CO 80045, USA; Neuroscience Graduate Program, University of Colorado Anschutz, Aurora, CO 80045, USA
| | - Samantha Schwartz
- University of Colorado Anschutz, Department of Pharmacology, Aurora, CO 80045, USA
| | - Matthew J Kennedy
- University of Colorado Anschutz, Department of Pharmacology, Aurora, CO 80045, USA
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - Jason Aoto
- University of Colorado Anschutz, Department of Pharmacology, Aurora, CO 80045, USA.
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12
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Uchigashima M, Cheung A, Futai K. Neuroligin-3: A Circuit-Specific Synapse Organizer That Shapes Normal Function and Autism Spectrum Disorder-Associated Dysfunction. Front Mol Neurosci 2021; 14:749164. [PMID: 34690695 PMCID: PMC8526735 DOI: 10.3389/fnmol.2021.749164] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/06/2021] [Indexed: 01/02/2023] Open
Abstract
Chemical synapses provide a vital foundation for neuron-neuron communication and overall brain function. By tethering closely apposed molecular machinery for presynaptic neurotransmitter release and postsynaptic signal transduction, circuit- and context- specific synaptic properties can drive neuronal computations for animal behavior. Trans-synaptic signaling via synaptic cell adhesion molecules (CAMs) serves as a promising mechanism to generate the molecular diversity of chemical synapses. Neuroligins (Nlgns) were discovered as postsynaptic CAMs that can bind to presynaptic CAMs like Neurexins (Nrxns) at the synaptic cleft. Among the four (Nlgn1-4) or five (Nlgn1-3, Nlgn4X, and Nlgn4Y) isoforms in rodents or humans, respectively, Nlgn3 has a heterogeneous expression and function at particular subsets of chemical synapses and strong association with non-syndromic autism spectrum disorder (ASD). Several lines of evidence have suggested that the unique expression and function of Nlgn3 protein underlie circuit-specific dysfunction characteristic of non-syndromic ASD caused by the disruption of Nlgn3 gene. Furthermore, recent studies have uncovered the molecular mechanism underlying input cell-dependent expression of Nlgn3 protein at hippocampal inhibitory synapses, in which trans-synaptic signaling of specific alternatively spliced isoforms of Nlgn3 and Nrxn plays a critical role. In this review article, we overview the molecular, anatomical, and physiological knowledge about Nlgn3, focusing on the circuit-specific function of mammalian Nlgn3 and its underlying molecular mechanism. This will provide not only new insight into specific Nlgn3-mediated trans-synaptic interactions as molecular codes for synapse specification but also a better understanding of the pathophysiological basis for non-syndromic ASD associated with functional impairment in Nlgn3 gene.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Cellular Neuropathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Amy Cheung
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, United States
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, United States
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13
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Blockus H, Rolotti SV, Szoboszlay M, Peze-Heidsieck E, Ming T, Schroeder A, Apostolo N, Vennekens KM, Katsamba PS, Bahna F, Mannepalli S, Ahlsen G, Honig B, Shapiro L, de Wit J, Losonczy A, Polleux F. Synaptogenic activity of the axon guidance molecule Robo2 underlies hippocampal circuit function. Cell Rep 2021; 37:109828. [PMID: 34686348 PMCID: PMC8605498 DOI: 10.1016/j.celrep.2021.109828] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 07/06/2021] [Accepted: 09/22/2021] [Indexed: 01/03/2023] Open
Abstract
Synaptic connectivity within adult circuits exhibits a remarkable degree of cellular and subcellular specificity. We report that the axon guidance receptor Robo2 plays a role in establishing synaptic specificity in hippocampal CA1. In vivo, Robo2 is present and required postsynaptically in CA1 pyramidal neurons (PNs) for the formation of excitatory (E) but not inhibitory (I) synapses, specifically in proximal but not distal dendritic compartments. In vitro approaches show that the synaptogenic activity of Robo2 involves a trans-synaptic interaction with presynaptic Neurexins, as well as binding to its canonical extracellular ligand Slit. In vivo 2-photon Ca2+ imaging of CA1 PNs during spatial navigation in awake behaving mice shows that preventing Robo2-dependent excitatory synapse formation cell autonomously during development alters place cell properties of adult CA1 PNs. Our results identify a trans-synaptic complex linking the establishment of synaptic specificity to circuit function.
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Affiliation(s)
- Heike Blockus
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Sebi V Rolotti
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Miklos Szoboszlay
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Eugénie Peze-Heidsieck
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Tiffany Ming
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Anna Schroeder
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Nuno Apostolo
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Kristel M Vennekens
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Phinikoula S Katsamba
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Fabiana Bahna
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Seetha Mannepalli
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Goran Ahlsen
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Barry Honig
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Joris de Wit
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
| | - Franck Polleux
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
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14
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Distinct Expression of SLM2 Underlies Splicing-Dependent Trans-Synaptic Signaling of Neurexin Across GABAergic Neuron Subtypes. Neurochem Res 2021; 47:2591-2601. [PMID: 34196888 DOI: 10.1007/s11064-021-03384-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/25/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
The mammalian brain contains multiple types of neuronal cells with complex assemblies and distinct structural and functional properties encoded by divergent gene programs. There is increasing evidence that alternative splicing (AS) plays fundamental roles in transcriptomic diversity and specifying synaptic properties of each neuronal cell type. However, the mechanisms underlying AS regulation and whether it controls synapse formation across GABAergic interneurons have not been fully elucidated. Here we show the differential expression levels of Sam68-like molecule 2 (SLM2), a major splicing regulator of neurexin (NRX), in GABAergic neuronal subtypes and its contribution to GABAergic synapse specification. Cortical SLM2 is strongly expressed not only in excitatory neurons but also in a subpopulation of GABAergic interneurons, especially in VIP-positive neurons that are originated from late-born caudal ganglionic eminence (GE)- derived cells. Using artificial synapse formation assay, we found that GE containing cortices form a strong synapse with LRRTM2, a trans-synaptic receptor of the alternatively spliced segment 4 (AS4)(-) of NRX. SLM2 knock-down reduced the NRX AS4(-) isoform expression and hence weaken LRRTM2-induced synapse formation. The addition of NRX AS4(-) was sufficient to rescue the synaptic formation by LRRTM2 in SLM2 knock-down neurons. Thus, our findings suggest a novel function of SLM2 in modifying network formation of a specific population of GABAergic interneurons and contribute to a better understanding of the roles AS plays in regulating synapse specificity and neuronal molecular diversity.
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15
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Klatt O, Repetto D, Brockhaus J, Reissner C, El Khallouqi A, Rohlmann A, Heine M, Missler M. Endogenous β-neurexins on axons and within synapses show regulated dynamic behavior. Cell Rep 2021; 35:109266. [PMID: 34133920 DOI: 10.1016/j.celrep.2021.109266] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/21/2020] [Accepted: 05/26/2021] [Indexed: 11/25/2022] Open
Abstract
Neurexins are key organizer molecules that regulate synaptic function and are implicated in autism and schizophrenia. β-neurexins interact with numerous cell adhesion and receptor molecules, but their neuronal localization remains elusive. Using single-molecule tracking and high-resolution microscopy to detect neurexin1β and neurexin3β in primary hippocampal neurons from knockin mice, we demonstrate that endogenous β-neurexins are present in fewer than half of excitatory and inhibitory synapses. Moreover, we observe a large extrasynaptic pool of β-neurexins on axons and show that axonal β-neurexins diffuse with higher surface mobility than those transiently confined within synapses. Stimulation of neuronal activity further increases the mobility of synaptic and axonal β-neurexins, whereas inhibition causes the opposite. Blocking ectodomain cleavage by metalloproteases also reduces β-neurexin mobility and enhances glutamate release. These findings suggest that the surface mobility of endogenous β-neurexins inside and outside of synapses is dynamically regulated and linked to neuronal activity.
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Affiliation(s)
- Oliver Klatt
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany; Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Daniele Repetto
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Johannes Brockhaus
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Carsten Reissner
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Abderazzaq El Khallouqi
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Martin Heine
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany.
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany.
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16
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Sticco MJ, Peña Palomino PA, Lukacsovich D, Thompson BL, Földy C, Ressl S, Martinelli DC. C1QL3 promotes cell-cell adhesion by mediating complex formation between ADGRB3/BAI3 and neuronal pentraxins. FASEB J 2021; 35:e21194. [PMID: 33337553 DOI: 10.1096/fj.202000351rr] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 11/11/2022]
Abstract
Synapses are the fundamental structural unit by which neurons communicate. An orchestra of proteins regulates diverse synaptic functions, including synapse formation, maintenance, and elimination-synapse homeostasis. Some proteins of the larger C1q super-family are synaptic organizers involved in crucial neuronal processes in various brain regions. C1Q-like (C1QL) proteins bind to the adhesion G protein-coupled receptor B3 (ADGRB3) and act at synapses in a subset of circuits. To investigate the hypothesis that the secreted C1QL proteins mediate tripartite trans-synaptic adhesion complexes, we conducted an in vivo interactome study and identified new binding candidates. We demonstrate that C1QL3 mediates a novel cell-cell adhesion complex involving ADGRB3 and two neuronal pentraxins, NPTX1 and NPTXR. Analysis of single-cell RNA-Seq data from the cerebral cortex shows that C1ql3, Nptx1, and Nptxr are highly co-expressed in the same excitatory neurons. Thus, our results suggest the possibility that in vivo the three co-expressed proteins are presynaptically secreted and form a complex capable of binding to postsynaptically localized ADGRB3, thereby creating a novel trans-synaptic adhesion complex. Identifying new binding partners for C1QL proteins and deciphering their underlying molecular principles will accelerate our understanding of their role in synapse organization.
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Affiliation(s)
- Matthew J Sticco
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Perla A Peña Palomino
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich, Switzerland
| | - Brianna L Thompson
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, Zürich, Switzerland
| | - Susanne Ressl
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - David C Martinelli
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,The Connecticut Institute for the Brain and Cognitive Sciences (IBACS), Storrs, CT, USA
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17
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Aerobic Exercise Induces Alternative Splicing of Neurexins in Frontal Cortex. J Funct Morphol Kinesiol 2021; 6:jfmk6020048. [PMID: 34072692 PMCID: PMC8261640 DOI: 10.3390/jfmk6020048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/02/2022] Open
Abstract
Aerobic exercise (AE) is known to produce beneficial effects on brain health by improving plasticity, connectivity, and cognitive functions, but the underlying molecular mechanisms are still limited. Neurexins (Nrxns) are a family of presynaptic cell adhesion molecules that are important in synapsis formation and maturation. In vertebrates, three-neurexin genes (NRXN1, NRXN2, and NRXN3) have been identified, each encoding for α and β neurexins, from two independent promoters. Moreover, each Nrxns gene (1-3) has several alternative exons and produces many splice variants that bind to a large variety of postsynaptic ligands, playing a role in trans-synaptic specification, strength, and plasticity. In this study, we investigated the impact of a continuous progressive (CP) AE program on alternative splicing (AS) of Nrxns on two brain regions: frontal cortex (FC) and hippocampus. We showed that exercise promoted Nrxns1-3 AS at splice site 4 (SS4) both in α and β isoforms, inducing a switch from exon-excluded isoforms (SS4-) to exon-included isoforms (SS4+) in FC but not in hippocampus. Additionally, we showed that the same AE program enhanced the expression level of other genes correlated with synaptic function and plasticity only in FC. Altogether, our findings demonstrated the positive effect of CP AE on FC in inducing molecular changes underlying synaptic plasticity and suggested that FC is possibly a more sensitive structure than hippocampus to show molecular changes.
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18
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Yoshida T, Yamagata A, Imai A, Kim J, Izumi H, Nakashima S, Shiroshima T, Maeda A, Iwasawa-Okamoto S, Azechi K, Osaka F, Saitoh T, Maenaka K, Shimada T, Fukata Y, Fukata M, Matsumoto J, Nishijo H, Takao K, Tanaka S, Okabe S, Tabuchi K, Uemura T, Mishina M, Mori H, Fukai S. Canonical versus non-canonical transsynaptic signaling of neuroligin 3 tunes development of sociality in mice. Nat Commun 2021; 12:1848. [PMID: 33758193 PMCID: PMC7988105 DOI: 10.1038/s41467-021-22059-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 02/25/2021] [Indexed: 12/31/2022] Open
Abstract
Neuroligin 3 (NLGN3) and neurexins (NRXNs) constitute a canonical transsynaptic cell-adhesion pair, which has been implicated in autism. In autism spectrum disorder (ASD) development of sociality can be impaired. However, the molecular mechanism underlying NLGN3-mediated social development is unclear. Here, we identify non-canonical interactions between NLGN3 and protein tyrosine phosphatase δ (PTPδ) splice variants, competing with NRXN binding. NLGN3-PTPδ complex structure revealed a splicing-dependent interaction mode and competition mechanism between PTPδ and NRXNs. Mice carrying a NLGN3 mutation that selectively impairs NLGN3-NRXN interaction show increased sociability, whereas mice where the NLGN3-PTPδ interaction is impaired exhibit impaired social behavior and enhanced motor learning, with imbalance in excitatory/inhibitory synaptic protein expressions, as reported in the Nlgn3 R451C autism model. At neuronal level, the autism-related Nlgn3 R451C mutation causes selective impairment in the non-canonical pathway. Our findings suggest that canonical and non-canonical NLGN3 pathways compete and regulate the development of sociality.
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Affiliation(s)
- Tomoyuki Yoshida
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan. .,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan. .,JST PRESTO, Saitama, Japan.
| | | | - Ayako Imai
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Juhyon Kim
- Division of Bio-Information Engineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Hironori Izumi
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Shogo Nakashima
- Department of System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Tomoko Shiroshima
- Department of Anatomy, Kitasato University School of Medicine, Kanagawa, Japan
| | - Asami Maeda
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shiho Iwasawa-Okamoto
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Kenji Azechi
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Fumina Osaka
- Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Takashi Saitoh
- Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Katsumi Maenaka
- Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.,Laboratory of Biomolecular Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Takashi Shimada
- SHIMADZU Bioscience Research Partnership, Innovation Center, Shimadzu Scientific Instruments, Bothell, WA, USA
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Aichi, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Aichi, Japan
| | - Jumpei Matsumoto
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.,Department of System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Hisao Nishijo
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.,Department of System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Keizo Takao
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.,Life Science Research Center, University of Toyama, Toyama, Japan
| | - Shinji Tanaka
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Katsuhiko Tabuchi
- JST PRESTO, Saitama, Japan.,Department of Molecular and Cellular Physiology, Institute of Medicine, Academic Assembly, Shinshu University, Nagano, Japan.,Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, Japan
| | - Takeshi Uemura
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, Japan.,Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu University, Nagano, Japan
| | - Masayoshi Mishina
- Brain Science Laboratory, Research Organization of Science and Technology, Ritsumeikan University, Shiga, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan.,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Shuya Fukai
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan.
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19
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Abstract
The function of neuronal circuits relies on the properties of individual neuronal cells and their synapses. We propose that a substantial degree of synapse formation and function is instructed by molecular codes resulting from transcriptional programmes. Recent studies on the Neurexin protein family and its ligands provide fundamental insight into how synapses are assembled and remodelled, how synaptic properties are specified and how single gene mutations associated with neurodevelopmental and psychiatric disorders might modify the operation of neuronal circuits and behaviour. In this Review, we first summarize insights into Neurexin function obtained from various model organisms. We then discuss the mechanisms and logic of the cell type-specific regulation of Neurexin isoforms, in particular at the level of alternative mRNA splicing. Finally, we propose a conceptual framework for how combinations of synaptic protein isoforms act as 'senders' and 'readers' to instruct synapse formation and the acquisition of cell type-specific and synapse-specific functional properties.
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20
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Uchigashima M, Konno K, Demchak E, Cheung A, Watanabe T, Keener DG, Abe M, Le T, Sakimura K, Sasaoka T, Uemura T, Imamura Kawasawa Y, Watanabe M, Futai K. Specific Neuroligin3-αNeurexin1 signaling regulates GABAergic synaptic function in mouse hippocampus. eLife 2020; 9:e59545. [PMID: 33355091 PMCID: PMC7758064 DOI: 10.7554/elife.59545] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 12/08/2020] [Indexed: 12/11/2022] Open
Abstract
Synapse formation and regulation require signaling interactions between pre- and postsynaptic proteins, notably cell adhesion molecules (CAMs). It has been proposed that the functions of neuroligins (Nlgns), postsynaptic CAMs, rely on the formation of trans-synaptic complexes with neurexins (Nrxns), presynaptic CAMs. Nlgn3 is a unique Nlgn isoform that localizes at both excitatory and inhibitory synapses. However, Nlgn3 function mediated via Nrxn interactions is unknown. Here we demonstrate that Nlgn3 localizes at postsynaptic sites apposing vesicular glutamate transporter 3-expressing (VGT3+) inhibitory terminals and regulates VGT3+ inhibitory interneuron-mediated synaptic transmission in mouse organotypic slice cultures. Gene expression analysis of interneurons revealed that the αNrxn1+AS4 splice isoform is highly expressed in VGT3+ interneurons as compared with other interneurons. Most importantly, postsynaptic Nlgn3 requires presynaptic αNrxn1+AS4 expressed in VGT3+ interneurons to regulate inhibitory synaptic transmission. Our results indicate that specific Nlgn-Nrxn signaling generates distinct functional properties at synapses.
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Affiliation(s)
- Motokazu Uchigashima
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
- Department of Cellular Neuropathology, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Kohtarou Konno
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Emily Demchak
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Takuya Watanabe
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - David G Keener
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Timmy Le
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Toshikuni Sasaoka
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata UniversityNiigataJapan
| | - Takeshi Uemura
- Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu UniversityNaganoJapan
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu UniversityNaganoJapan
| | - Yuka Imamura Kawasawa
- Department of Biochemistry and Molecular Biology and Institute for Personalized Medicine, Pennsylvania State University College of MedicineHersheyUnited States
- Department of Pharmacology Pennsylvania State University College of MedicineHersheyUnited States
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido UniversitySapporoJapan
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical SchoolWorcesterUnited States
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21
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Comoletti D, Trobiani L, Chatonnet A, Bourne Y, Marchot P. Comparative mapping of selected structural determinants on the extracellular domains of cholinesterase-like cell-adhesion molecules. Neuropharmacology 2020; 184:108381. [PMID: 33166544 DOI: 10.1016/j.neuropharm.2020.108381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/10/2020] [Accepted: 10/29/2020] [Indexed: 11/18/2022]
Abstract
Cell adhesion generally involves formation of homophilic or heterophilic protein complexes between two cells to form transcellular junctions. Neural cell-adhesion members of the α/β-hydrolase fold superfamily of proteins use their extracellular or soluble cholinesterase-like domain to bind cognate partners across cell membranes, as illustrated by the neuroligins. These cell-adhesion molecules currently comprise the synaptic organizers neuroligins found in all animal phyla, along with three proteins found only in invertebrates: the guidance molecule neurotactin, the glia-specific gliotactin, and the basement membrane protein glutactin. Although these proteins share a cholinesterase-like fold, they lack one or more residues composing the catalytic triad responsible for the enzymatic activity of the cholinesterases. Conversely, they are found in various subcellular localisations and display specific disulfide bonding and N-glycosylation patterns, along with individual surface determinants possibly associated with recognition and binding of protein partners. Formation of non-covalent dimers typical of the cholinesterases is documented for mammalian neuroligins, yet whether invertebrate neuroligins and their neurotactin, gliotactin and glutactin relatives also form dimers in physiological conditions is unknown. Here we provide a brief overview of the localization, function, evolution, and conserved versus individual structural determinants of these cholinesterase-like cell-adhesion proteins. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Davide Comoletti
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand; Child Health Institute of New Jersey, New Brunswick, NJ 08901, USA; Department of Neuroscience and Cell Biology Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Laura Trobiani
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Arnaud Chatonnet
- Lab 'Dynamique Musculaire et Métabolisme', Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE) / Université Montpellier, Montpellier, France
| | - Yves Bourne
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France
| | - Pascale Marchot
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France.
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22
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Trobiani L, Meringolo M, Diamanti T, Bourne Y, Marchot P, Martella G, Dini L, Pisani A, De Jaco A, Bonsi P. The neuroligins and the synaptic pathway in Autism Spectrum Disorder. Neurosci Biobehav Rev 2020; 119:37-51. [PMID: 32991906 DOI: 10.1016/j.neubiorev.2020.09.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 12/13/2022]
Abstract
The genetics underlying autism spectrum disorder (ASD) is complex and heterogeneous, and de novo variants are found in genes converging in functional biological processes. Neuronal communication, including trans-synaptic signaling involving two families of cell-adhesion proteins, the presynaptic neurexins and the postsynaptic neuroligins, is one of the most recurrently affected pathways in ASD. Given the role of these proteins in determining synaptic function, abnormal synaptic plasticity and failure to establish proper synaptic contacts might represent mechanisms underlying risk of ASD. More than 30 mutations have been found in the neuroligin genes. Most of the resulting residue substitutions map in the extracellular, cholinesterase-like domain of the protein, and impair protein folding and trafficking. Conversely, the stalk and intracellular domains are less affected. Accordingly, several genetic animal models of ASD have been generated, showing behavioral and synaptic alterations. The aim of this review is to discuss the current knowledge on ASD-linked mutations in the neuroligin proteins and their effect on synaptic function, in various brain areas and circuits.
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Affiliation(s)
- Laura Trobiani
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Maria Meringolo
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Tamara Diamanti
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Yves Bourne
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Pascale Marchot
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Giuseppina Martella
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Luciana Dini
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Antonio Pisani
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Antonella De Jaco
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
| | - Paola Bonsi
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy.
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23
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Oku S, Feng H, Connor S, Toledo A, Zhang P, Zhang Y, Thoumine O, Zhang C, Craig AM. Alternative splicing at neuroligin site A regulates glycan interaction and synaptogenic activity. eLife 2020; 9:58668. [PMID: 32915137 PMCID: PMC7486126 DOI: 10.7554/elife.58668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/31/2020] [Indexed: 01/18/2023] Open
Abstract
Post-transcriptional mechanisms regulating cell surface synaptic organizing complexes that control the properties of connections in brain circuits are poorly understood. Alternative splicing regulates the prototypical synaptic organizing complex, neuroligin-neurexin. In contrast to the well-studied neuroligin splice site B, little is known about splice site A. We discovered that inclusion of the positively charged A1 insert in mouse neuroligin-1 increases its binding to heparan sulphate, a modification on neurexin. The A1 insert increases neurexin recruitment, presynaptic differentiation, and synaptic transmission mediated by neuroligin-1. We propose that the A1 insert could be a target for alleviating the consequences of deleterious NLGN1/3 mutations, supported by assays with the autism-linked neuroligin-1-P89L mutant. An enrichment of neuroligin-1 A1 in GABAergic neuron types suggests a role in synchrony of cortical circuits. Altogether, these data reveal an unusual mode by which neuroligin splicing controls synapse development through protein-glycan interaction and identify it as a potential therapeutic target.
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Affiliation(s)
- Shinichiro Oku
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Huijuan Feng
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Steven Connor
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada.,Department of Biology, York University, Toronto, Canada
| | - Andrea Toledo
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Peng Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Yue Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Chaolin Zhang
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
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24
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Modeling a Neurexin-3α Human Mutation in Mouse Neurons Identifies a Novel Role in the Regulation of Transsynaptic Signaling and Neurotransmitter Release at Excitatory Synapses. J Neurosci 2019; 39:9065-9082. [PMID: 31578233 DOI: 10.1523/jneurosci.1261-19.2019] [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: 05/30/2019] [Revised: 09/13/2019] [Accepted: 09/22/2019] [Indexed: 12/27/2022] Open
Abstract
Presynaptic α-neurexins are highly expressed and more frequently linked to neuropsychiatric and neurodevelopmental disorders than β-neurexins. However, how extracellular sequences specific to α-neurexins enable synaptic transmission is poorly understood. We identified a mutation in an extracellular region of neurexin-3α (A687T), located in a region conserved among α-neurexins and throughout vertebrate evolution, in a patient diagnosed with profound intellectual disability and epilepsy. We systematically interrogated this mutation using a knockdown-replacement approach, and discovered that the A687T mutation enhanced presynaptic morphology and increased two critical presynaptic parameters: (1) presynaptic release probability, and (2) the size of the readily releasable pool exclusively at excitatory synapses in mixed sex primary mouse hippocampal cultures. Introduction of the mutation in vivo and subsequent analysis in ex vivo brain slices made from male and female mice revealed a significant increase in excitatory presynaptic neurotransmission that occluded presynaptic but not postsynaptic LTP. Mechanistically, neurexin-3αA687T enhanced binding to LRRTM2 without altering binding to postsynaptic neuroligin-1. Thus, neurexin-3αA687T unexpectedly produced the first neurexin presynaptic gain-of-function phenotype and revealed unanticipated novel insights into how α-neurexin extracellular sequences govern both transsynaptic adhesion and presynaptic neurotransmitter release.SIGNIFICANCE STATEMENT Despite decades of scientific scrutiny, how precise α-neurexin extracellular sequences control synapse function remains enigmatic. One largely unpursued avenue to identify the role of precise extracellular sequences is the interrogation of naturally occurring missense mutations. Here, we identified a neurexin-3α missense mutation in a compound heterozygous patient diagnosed with profound intellectual disability and epilepsy and systematically interrogated this mutation. Using in vitro and in vivo molecular replacement, electrophysiology, electron microscopy, and structure-function analyses, we reveal a novel role for neurexin-3α, unanticipated based on α-neurexin knock-out models, in controlling presynaptic morphology and neurotransmitter release at excitatory synapses. Our findings represent the first neurexin gain-of-function phenotype and provide new fundamentally important insight into the synaptic biology of α-neurexins.
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25
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Neurexins - versatile molecular platforms in the synaptic cleft. Curr Opin Struct Biol 2019; 54:112-121. [PMID: 30831539 DOI: 10.1016/j.sbi.2019.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 01/05/2023]
Abstract
Neurexins constitute a large family of synaptic organizers. Their extracellular domains protrude into the synaptic cleft where they can form transsynaptic bridges with different partners. A unique constellation of structural elements within their ectodomains enables neurexins to create molecular platforms within the synaptic cleft that permit a large portfolio of partners to be recruited, assembled and their interactions to be dynamically regulated. Neurexins and their partners are implicated in neuropsychiatric diseases including autism spectrum disorder and schizophrenia. Detailed understanding of the mechanisms that underlie neurexin interactions may in future guide the design of tools to manipulate synaptic connections and their function, in particular those involved in the pathogenesis of neuropsychiatric disease.
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26
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Uchigashima M, Cheung A, Suh J, Watanabe M, Futai K. Differential expression of neurexin genes in the mouse brain. J Comp Neurol 2019; 527:1940-1965. [PMID: 30761534 DOI: 10.1002/cne.24664] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/04/2019] [Accepted: 02/01/2019] [Indexed: 01/22/2023]
Abstract
Synapses, highly specialized membrane junctions between neurons, connect presynaptic neurotransmitter release sites and postsynaptic ligand-gated channels. Neurexins (Nrxns), a family of presynaptic adhesion molecules, have been characterized as major regulators of synapse development and function. Via their extracellular domains, Nrxns bind to different postsynaptic proteins, generating highly diverse functional readouts through their postsynaptic binding partners. Not surprisingly given these versatile protein interactions, mutations and deletions of Nrxn genes have been identified in patients with autism spectrum disorders, intellectual disabilities, and schizophrenia. Therefore, elucidating the expression profiles of Nrxns in the brain is of high significance. Here, using chromogenic and fluorescent in situ hybridization, we characterize the expression patterns of Nrxn isoforms throughout the brain. We found that each Nrxn isoform displays a unique expression profile in a region-, cell type-, and sensory system-specific manner. Interestingly, we also found that αNrxn1 and αNrxn2 mRNAs are expressed in non-neuronal cells, including astrocytes and oligodendrocytes. Lastly, we found diverse expression patterns of genes that encode Nrxn binding proteins, such as Neuroligins (Nlgns), Leucine-rich repeat transmembrane neuronal protein (Lrrtms) and Latrophilins (Adgrls), suggesting that Nrxn proteins can mediate numerous combinations of trans-synaptic interactions. Together, our anatomical profiling of Nrxn gene expression reflects the diverse roles of Nrxn molecules.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts.,Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Amy Cheung
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Julie Suh
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
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27
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Yamagata A, Fukai S. Structural insights into leucine-rich repeat-containing synaptic cleft molecules. Curr Opin Struct Biol 2019; 54:68-77. [PMID: 30784960 DOI: 10.1016/j.sbi.2019.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 11/28/2018] [Accepted: 01/07/2019] [Indexed: 02/04/2023]
Abstract
Synapses are cell adhesion structures specialized for signal transmission between neurons. At the synapse, presynaptic and postsynaptic terminals of neurons are functionally connected but spatially separated and form a cleft. Membrane receptor-like cell adhesion molecules and secreted proteins in the synaptic cleft (synaptic cleft molecules) can mediate structural and functional linkages between the presynaptic and postsynaptic terminals for neural development or activity. A leucine-rich repeat (LRR) has been known as a typical structural motif for protein-protein interactions and plays important roles in intermolecular interactions mediated by synaptic cleft molecules. In this review, we summarize structural insights into LRR-containing synaptic cleft molecules from recent structural studies and discuss how they are linked to their downstream events.
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Affiliation(s)
- Atsushi Yamagata
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan; Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo 113-0032, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan.
| | - Shuya Fukai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan; Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo 113-0032, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan.
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28
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Yamagata A, Goto-Ito S, Sato Y, Shiroshima T, Maeda A, Watanabe M, Saitoh T, Maenaka K, Terada T, Yoshida T, Uemura T, Fukai S. Structural insights into modulation and selectivity of transsynaptic neurexin-LRRTM interaction. Nat Commun 2018; 9:3964. [PMID: 30262834 PMCID: PMC6160412 DOI: 10.1038/s41467-018-06333-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
Leucine-rich repeat transmembrane neuronal proteins (LRRTMs) function as postsynaptic organizers that induce excitatory synapses. Neurexins (Nrxns) and heparan sulfate proteoglycans have been identified as presynaptic ligands for LRRTMs. Specifically, LRRTM1 and LRRTM2 bind to the Nrxn splice variant lacking an insert at the splice site 4 (S4). Here, we report the crystal structure of the Nrxn1β–LRRTM2 complex at 3.4 Å resolution. The Nrxn1β–LRRTM2 interface involves Ca2+-mediated interactions and overlaps with the Nrxn–neuroligin interface. Together with structure-based mutational analyses at the molecular and cellular levels, the present structural analysis unveils the mechanism of selective binding between Nrxn and LRRTM1/2 and its modulation by the S4 insertion of Nrxn. Leucine-rich repeat transmembrane neuronal proteins (LRRTMs) function as postsynaptic organizers that induce excitatory synapses. Here authors solve the crystal structure of LRRTM2 in complex with its ligand Nrxn1β and shed light on how selective binding of ligands to LRRTM1/2 is achieved.
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Affiliation(s)
- Atsushi Yamagata
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,CREST, JST, Saitama, 332-0012, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan
| | - Sakurako Goto-Ito
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,CREST, JST, Saitama, 332-0012, Japan
| | - Yusuke Sato
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,CREST, JST, Saitama, 332-0012, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan
| | - Tomoko Shiroshima
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,CREST, JST, Saitama, 332-0012, Japan
| | - Asami Maeda
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,CREST, JST, Saitama, 332-0012, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Faculty of Medicine, Sapporo, 060-8638, Japan
| | - Takashi Saitoh
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Hokkaido University of Science, Sapporo, 006-8585, Japan
| | - Katsumi Maenaka
- Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, 060-0812, Japan.,Laboratory of Biomolecular Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, 060-0812, Japan
| | - Tohru Terada
- Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan.,PRESTO, JST, Saitama, 332-0012, Japan
| | - Takeshi Uemura
- CREST, JST, Saitama, 332-0012, Japan. .,Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu University, Nagano, 390-8621, Japan. .,Department of Biological Sciences for Intractable Neurological Diseases, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan.
| | - Shuya Fukai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan. .,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan. .,CREST, JST, Saitama, 332-0012, Japan. .,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan.
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29
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Cbln1 and Cbln4 Are Structurally Similar but Differ in GluD2 Binding Interactions. Cell Rep 2018; 20:2328-2340. [PMID: 28877468 DOI: 10.1016/j.celrep.2017.08.031] [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: 11/28/2016] [Revised: 07/06/2017] [Accepted: 08/07/2017] [Indexed: 11/23/2022] Open
Abstract
Unlike cerebellin 1 (Cbln1), which bridges neurexin (Nrxn) receptors and δ-type glutamate receptors in a trans-synaptic triad, Cbln4 was reported to have no or weak binding for the receptors despite sharing ∼70% sequence identity with Cbln1. Here, we report crystal structures of the homotrimers of the C1q domain of Cbln1 and Cbln4 at 2.2 and 2.3 Å resolution, respectively. Comparison of the structures suggests that the difference between Cbln1 and Cbln4 in GluD2 binding might be because of their sequence and structural divergence in loop CD. Surprisingly, we show that Cbln4 binds to Nrxn1β and forms a stable complex with the laminin, nectin, sex-hormone binding globulin (LNS) domain of Nrxn1β. Furthermore, the negative-stain electron microscopy reconstruction of hexameric full-length Cbln1 at 13 Å resolution and that of the Cbln4/Nrxn1β complex at 19 Å resolution suggest that Nrxn1β binds to the N-terminal region of Cbln4, probably through strand β10 of the S4 insert.
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30
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Neuroligin-induced presynaptic differentiation through SLM2-mediated splicing modifications of neurexin in cerebellar cultures. Biochem Biophys Res Commun 2017; 493:1030-1036. [PMID: 28939043 DOI: 10.1016/j.bbrc.2017.09.097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 09/18/2017] [Indexed: 11/21/2022]
Abstract
Neurexins (NRXs) and neuroligins (NLs) play important roles in synapse specification. The alternatively spliced segment 4 (AS4) of NRX genes (Nrxn) is a critical element in selective trans-synaptic interactions. However, the role of splicing of NRXs and NLs in synapse specification is not fully understood. To investigate the exact role of splice-dependent NRX-NL interaction in the specification of glutamatergic and gamma-aminobutyric acid (GABA)-ergic synapses in the cerebellum, we evaluated the synaptogenic receptor activity of NL1/2/3 isoforms in a neuron-fibroblast co-culture system, in which the Nrxn AS4 segments are manipulated using SLM2, a selective and dominant regulator of AS4 splicing. We show that ectopic SLM2 expression (SLM2 E/E) causes marked skipping of exon 20 of AS4 in cerebellar neuron culture. Whereas NLs can induce VAMP2+ presynaptic contacts from mainly glutamatergic neurons in both uninfected (control) and SLM2 E/E co-cultures, they induce VGAT+ GABAergic contacts in the control culture, but not properly in the SLM2 E/E culture. Furthermore, Nrxn3 is responsible for the NL-induced assembly of GABAergic synapses in co-culture. Importantly, lentivirus-based expression of Nrxn3 containing exon 20 restores the reduced NL-induced GABAergic contacts in the SLM2 E/E co-culture. Therefore, our findings may provide further insights into NRX-NL mediated synapse specification.
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31
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Elegheert J, Cvetkovska V, Clayton AJ, Heroven C, Vennekens KM, Smukowski SN, Regan MC, Jia W, Smith AC, Furukawa H, Savas JN, de Wit J, Begbie J, Craig AM, Aricescu AR. Structural Mechanism for Modulation of Synaptic Neuroligin-Neurexin Signaling by MDGA Proteins. Neuron 2017; 95:896-913.e10. [PMID: 28817804 PMCID: PMC5563082 DOI: 10.1016/j.neuron.2017.07.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 06/22/2017] [Accepted: 07/28/2017] [Indexed: 01/30/2023]
Abstract
Neuroligin-neurexin (NL-NRX) complexes are fundamental synaptic organizers in the central nervous system. An accurate spatial and temporal control of NL-NRX signaling is crucial to balance excitatory and inhibitory neurotransmission, and perturbations are linked with neurodevelopmental and psychiatric disorders. MDGA proteins bind NLs and control their function and interaction with NRXs via unknown mechanisms. Here, we report crystal structures of MDGA1, the NL1-MDGA1 complex, and a spliced NL1 isoform. Two large, multi-domain MDGA molecules fold into rigid triangular structures, cradling a dimeric NL to prevent NRX binding. Structural analyses guided the discovery of a broad, splicing-modulated interaction network between MDGA and NL family members and helped rationalize the impact of autism-linked mutations. We demonstrate that expression levels largely determine whether MDGAs act selectively or suppress the synapse organizing function of multiple NLs. These results illustrate a potentially brain-wide regulatory mechanism for NL-NRX signaling modulation. The MDGA1 extracellular region has an unusual triangular multi-domain arrangement The NL1-MDGA1 complex structure reveals how MDGA proteins block neurexin binding MDGA1 and MDGA2 bind all NL isoforms, a process fine-tuned by alternative splicing MDGA1 and MDGA2 suppress NL synaptogenic activity in a concentration-dependent manner
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Affiliation(s)
- Jonathan Elegheert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
| | - Vedrana Cvetkovska
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Amber J Clayton
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Christina Heroven
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Kristel M Vennekens
- VIB Center for Brain and Disease Research, Herestraat 49, B-3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Samuel N Smukowski
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Michael C Regan
- Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Wanyi Jia
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Alexandra C Smith
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Hiro Furukawa
- Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Jeffrey N Savas
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Joris de Wit
- VIB Center for Brain and Disease Research, Herestraat 49, B-3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Jo Begbie
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK.
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32
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Kim JA, Kim D, Won SY, Han KA, Park D, Cho E, Yun N, An HJ, Um JW, Kim E, Lee JO, Ko J, Kim HM. Structural Insights into Modulation of Neurexin-Neuroligin Trans-synaptic Adhesion by MDGA1/Neuroligin-2 Complex. Neuron 2017. [PMID: 28641111 DOI: 10.1016/j.neuron.2017.05.034] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Membrane-associated mucin domain-containing glycosylphosphatidylinositol anchor proteins (MDGAs) bind directly to neuroligin-1 (NL1) and neuroligin-2 (NL2), thereby respectively regulating excitatory and inhibitory synapse development. However, the mechanisms by which MDGAs modulate NL activity to specify development of the two synapse types remain unclear. Here, we determined the crystal structures of human NL2/MDGA1 Ig1-3 complex, revealing their stable 2:2 arrangement with three interaction interfaces. Cell-based assays using structure-guided, site-directed MDGA1 mutants showed that all three contact patches were required for the MDGA's negative regulation of NL2-mediated synaptogenic activity. Furthermore, MDGA1 competed with neurexins for NL2 via its Ig1 domain. The binding affinities of both MDGA1 and MDGA2 for NL1 and NL2 were similar, consistent with the structural prediction of similar binding interfaces. However, MDGA1 selectively associated with NL2, but not NL1, in vivo. These findings collectively provide structural insights into the mechanism by which MDGAs negatively modulate synapse development governed by NLs/neurexins.
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Affiliation(s)
- Jung A Kim
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon 34141, Korea
| | | | - Kyung Ah Han
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Dongseok Park
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Eunju Cho
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Nayoung Yun
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, Korea
| | - Hyun Joo An
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, Korea
| | - Ji Won Um
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon 34141, Korea; Department of Biological Sciences, KAIST, Daejeon 34141, Korea
| | - Jie-Oh Lee
- Department of Chemistry, KAIST, Daejeon 34141, Korea
| | - Jaewon Ko
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
| | - Ho Min Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon 34141, Korea; Graduate School of Medical Science & Engineering, KAIST, Daejeon 34141, Korea.
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33
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Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity. Neural Plast 2017; 2017:6526151. [PMID: 28255461 PMCID: PMC5307005 DOI: 10.1155/2017/6526151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/13/2016] [Indexed: 12/13/2022] Open
Abstract
Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, forming trans-complexes spanning the synaptic cleft or cis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.
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34
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Yuzaki M, Aricescu AR. A GluD Coming-Of-Age Story. Trends Neurosci 2017; 40:138-150. [PMID: 28110935 DOI: 10.1016/j.tins.2016.12.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 01/02/2023]
Abstract
The GluD1 and GluD2 receptors form the GluD ionotropic glutamate receptor (iGluR) subfamily. Without known endogenous ligands, they have long been referred to as 'orphan' and remained enigmatic functionally. Recent progress has, however, radically changed this view. Both GluD receptors are expressed in wider brain regions than originally thought. Human genetic studies and analyses of knockout mice have revealed their involvement in multiple neurodevelopmental and psychiatric disorders. The discovery of endogenous ligands, together with structural investigations, has opened the way towards a mechanistic understanding of GluD signaling at central nervous system synapses. These studies have also prompted the hypothesis that all iGluRs, and potentially other neurotransmitter receptors, rely on the cooperative binding of extracellular small-molecule and protein ligands for physiological signaling.
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Affiliation(s)
- Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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35
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Harkin LF, Lindsay SJ, Xu Y, Alzu'bi A, Ferrara A, Gullon EA, James OG, Clowry GJ. Neurexins 1-3 Each Have a Distinct Pattern of Expression in the Early Developing Human Cerebral Cortex. Cereb Cortex 2017; 27:216-232. [PMID: 28013231 PMCID: PMC5654756 DOI: 10.1093/cercor/bhw394] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/16/2016] [Accepted: 12/02/2016] [Indexed: 12/17/2022] Open
Abstract
Neurexins (NRXNs) are presynaptic terminal proteins and candidate neurodevelopmental disorder susceptibility genes; mutations presumably upset synaptic stabilization and function. However, analysis of human cortical tissue samples by RNAseq and quantitative real-time PCR at 8-12 postconceptional weeks, prior to extensive synapse formation, showed expression of all three NRXNs as well as several potential binding partners. However, the levels of expression were not identical; NRXN1 increased with age and NRXN2 levels were consistently higher than for NRXN3. Immunohistochemistry for each NRXN also revealed different expression patterns at this stage of development. NRXN1 and NRXN3 immunoreactivity was generally strongest in the cortical plate and increased in the ventricular zone with age, but was weak in the synaptogenic presubplate (pSP) and marginal zone. On the other hand, NRXN2 colocalized with synaptophysin in neurites of the pSP, but especially with GAP43 and CASK in growing axons of the intermediate zone. Alternative splicing modifies the role of NRXNs and we found evidence by RNAseq for exon skipping at splice site 4 and concomitant expression of KHDBRS proteins which control this splicing. NRXN2 may play a part in early cortical synaptogenesis, but NRXNs could have diverse roles in development including axon guidance, and intercellular communication between proliferating cells and/or migrating neurons.
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Affiliation(s)
- Lauren F Harkin
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
- Present address: School of Healthcare Science, Manchester Metropolitan University, Manchester, M1 5GD, UK
| | - Susan J Lindsay
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
| | - Yaobo Xu
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
- Present address: Wellcome Trust, Sanger Institute, Cambridge, CB10 1SA, UK
| | - Ayman Alzu'bi
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
| | - Alexandra Ferrara
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
| | - Emily A Gullon
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
| | - Owen G James
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Parkway Drive, Newcastle upon Tyne NE1 3BZ, UK
- Present address: MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Gavin J Clowry
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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Elegheert J, Kakegawa W, Clay JE, Shanks NF, Behiels E, Matsuda K, Kohda K, Miura E, Rossmann M, Mitakidis N, Motohashi J, Chang VT, Siebold C, Greger IH, Nakagawa T, Yuzaki M, Aricescu AR. Structural basis for integration of GluD receptors within synaptic organizer complexes. Science 2016; 353:295-9. [PMID: 27418511 PMCID: PMC5291321 DOI: 10.1126/science.aae0104] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 06/17/2016] [Indexed: 12/25/2022]
Abstract
Ionotropic glutamate receptor (iGluR) family members are integrated into supramolecular complexes that modulate their location and function at excitatory synapses. However, a lack of structural information beyond isolated receptors or fragments thereof currently limits the mechanistic understanding of physiological iGluR signaling. Here, we report structural and functional analyses of the prototypical molecular bridge linking postsynaptic iGluR δ2 (GluD2) and presynaptic β-neurexin 1 (β-NRX1) via Cbln1, a C1q-like synaptic organizer. We show how Cbln1 hexamers "anchor" GluD2 amino-terminal domain dimers to monomeric β-NRX1. This arrangement promotes synaptogenesis and is essential for D: -serine-dependent GluD2 signaling in vivo, which underlies long-term depression of cerebellar parallel fiber-Purkinje cell (PF-PC) synapses and motor coordination in developing mice. These results lead to a model where protein and small-molecule ligands synergistically control synaptic iGluR function.
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Affiliation(s)
- Jonathan Elegheert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Jordan E Clay
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Natalie F Shanks
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37232-0615, USA
| | - Ester Behiels
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Keiko Matsuda
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kazuhisa Kohda
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Eriko Miura
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Maxim Rossmann
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Nikolaos Mitakidis
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Junko Motohashi
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Veronica T Chang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37232-0615, USA
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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37
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Lowther C, Speevak M, Armour CM, Goh ES, Graham GE, Li C, Zeesman S, Nowaczyk MJM, Schultz LA, Morra A, Nicolson R, Bikangaga P, Samdup D, Zaazou M, Boyd K, Jung JH, Siu V, Rajguru M, Goobie S, Tarnopolsky MA, Prasad C, Dick PT, Hussain AS, Walinga M, Reijenga RG, Gazzellone M, Lionel AC, Marshall CR, Scherer SW, Stavropoulos DJ, McCready E, Bassett AS. Molecular characterization of NRXN1 deletions from 19,263 clinical microarray cases identifies exons important for neurodevelopmental disease expression. Genet Med 2016; 19:53-61. [PMID: 27195815 PMCID: PMC4980119 DOI: 10.1038/gim.2016.54] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/16/2016] [Indexed: 01/31/2023] Open
Abstract
Purpose The purpose of the current study was to assess the penetrance of NRXN1 deletions. Methods We compared the prevalence and genomic extent of NRXN1 deletions identified among 19,263 clinically referred cases to that of 15,264 controls. The burden of additional clinically relevant CNVs was used as a proxy to estimate the relative penetrance of NRXN1 deletions. Results We identified 41 (0.21%) previously unreported exonic NRXN1 deletions ascertained for developmental delay/intellectual disability, significantly greater than in controls [OR=8.14 (95% CI 2.91–22.72), p< 0.0001)]. Ten (22.7%) of these had a second clinically relevant CNV. Subjects with a deletion near the 3′ end of NRXN1 were significantly more likely to have a second rare CNV than subjects with a 5′ NRXN1 deletion [OR=7.47 (95% CI 2.36–23.61), p=0.0006]. The prevalence of intronic NRXN1 deletions was not statistically different between cases and controls (p=0.618). The majority (63.2%) of intronic NRXN1 deletion cases had a second rare CNV, a two-fold greater prevalence than for exonic NRXN1 deletion cases (p=0.0035). Conclusions The results support the importance of exons near the 5′ end of NRXN1 in the expression of neurodevelopmental disorders. Intronic NRXN1 deletions do not appear to substantially increase the risk for clinical phenotypes.
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Affiliation(s)
- Chelsea Lowther
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Marsha Speevak
- Trillium Health Partners Credit Valley Site, Toronto, Ontario, Canada
| | - Christine M Armour
- Regional Genetics Program, Children's Hospital of Eastern Ontario, Toronto, ON, Canada
| | - Elaine S Goh
- Trillium Health Partners Credit Valley Site, Toronto, Ontario, Canada
| | - Gail E Graham
- Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Chumei Li
- Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada.,McMaster Children's Hospital, Department of Pediatrics and Clinical Genetics Program, Hamilton, Ontario, Canada
| | - Susan Zeesman
- McMaster Children's Hospital, Department of Pediatrics and Clinical Genetics Program, Hamilton, Ontario, Canada
| | - Malgorzata J M Nowaczyk
- McMaster Children's Hospital, Department of Pediatrics and Clinical Genetics Program, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Lee-Anne Schultz
- McMaster Children's Hospital, Department of Pediatrics and Clinical Genetics Program, Hamilton, Ontario, Canada
| | - Antonella Morra
- Trillium Health Partners Credit Valley Site, Toronto, Ontario, Canada
| | - Rob Nicolson
- Department of Psychiatry, Western University, London, Ontario, Canada
| | | | - Dawa Samdup
- Hotel Dieu Hospital, Child Development Centre, Kingston, Ontario, Canada
| | - Mostafa Zaazou
- Trillium Health Partners Credit Valley Site, Toronto, Ontario, Canada
| | - Kerry Boyd
- Department of Psychiatry, McMaster University, Hamilton, Ontario, Canada
| | - Jack H Jung
- London Health Sciences Centre, Children's Hospital of Western Ontario, London, Ontario, Canada
| | - Victoria Siu
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Ontario, Canada
| | | | - Sharan Goobie
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Ontario, Canada
| | - Mark A Tarnopolsky
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Chitra Prasad
- Department of Pediatrics, Schulich School of Medicine and Dentistry, London, Ontario, Canada
| | - Paul T Dick
- Grey Bruce Health Services, Owen Sound, Ontario, Canada
| | - Asmaa S Hussain
- London Health Sciences Centre, Children's Hospital of Western Ontario, London, Ontario, Canada
| | | | | | - Matthew Gazzellone
- The Centre for Applied Genomics, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Anath C Lionel
- The Centre for Applied Genomics, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Christian R Marshall
- The Centre for Applied Genomics, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephen W Scherer
- The Centre for Applied Genomics, the Hospital for Sick Children, Toronto, Ontario, Canada.,McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Dimitri J Stavropoulos
- Cytogenetics Laboratory, Department of Pediatric Laboratory Medicine, the Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elizabeth McCready
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Anne S Bassett
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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38
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Matsuda K, Budisantoso T, Mitakidis N, Sugaya Y, Miura E, Kakegawa W, Yamasaki M, Konno K, Uchigashima M, Abe M, Watanabe I, Kano M, Watanabe M, Sakimura K, Aricescu A, Yuzaki M. Transsynaptic Modulation of Kainate Receptor Functions by C1q-like Proteins. Neuron 2016; 90:752-67. [DOI: 10.1016/j.neuron.2016.04.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/29/2016] [Accepted: 03/30/2016] [Indexed: 12/31/2022]
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Abstract
UNLABELLED Synapses depend on trafficking of key membrane proteins by lateral diffusion from surface populations and by exocytosis from intracellular pools. The cell adhesion molecule neurexin (Nrxn) plays essential roles in synapses, but the dynamics and regulation of its trafficking are unknown. Here, we performed single-particle tracking and live imaging of transfected, epitope-tagged Nrxn variants in cultured rat and mouse wild-type or knock-out neurons. We observed that structurally larger αNrxn molecules are more mobile in the plasma membrane than smaller βNrxns because αNrxns displayed higher diffusion coefficients in extrasynaptic regions and excitatory or inhibitory terminals. We found that well characterized interactions with extracellular binding partners regulate the surface mobility of Nrxns. Binding to neurexophilin-1 (Nxph1) reduced the surface diffusion of αNrxns when both molecules were coexpressed. Conversely, impeding other interactions by insertion of splice sequence #4 or removal of extracellular Ca(2+) augmented the mobility of αNrxns and βNrxns. We also determined that fast axonal transport delivers Nrxns to the neuronal surface because Nrxns comigrate as cargo on synaptic vesicle protein transport vesicles (STVs). Unlike surface mobility, intracellular transport of βNrxn(+) STVs was faster than that of αNrxns, but both depended on the microtubule motor protein KIF1A and neuronal activity regulated the velocity. Large spontaneous fusion of Nrxn(+) STVs occurred simultaneously with synaptophysin on axonal membranes mostly outside of active presynaptic terminals. Surface Nrxns enriched at synaptic terminals where αNrxns and Nxph1/αNrxns recruited GABAAR subunits. Therefore, our results identify regulated dynamic trafficking as an important property of Nrxns that corroborates their function at synapses. SIGNIFICANCE STATEMENT Synapses mediate most functions in our brains and depend on the precise and timely delivery of key molecules throughout life. Neurexins (Nrxns) are essential synaptic cell adhesion molecules that are involved in synaptic transmission and differentiation of synaptic contacts. In addition, Nrxns have been linked to neuropsychiatric diseases such as autism. Because little is known about the dynamic aspects of trafficking of neurexins to synapses, we investigated this important question using single-molecule tracking and time-lapse imaging. We identify distinct differences between major Nrxn variants both in surface mobility and during intracellular transport. Because their dynamic behavior is highly regulated, for example, by different binding activities, these processes have immediate consequences for the function of Nrxns at synapses.
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40
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Gao R, Penzes P. Common mechanisms of excitatory and inhibitory imbalance in schizophrenia and autism spectrum disorders. Curr Mol Med 2015; 15:146-67. [PMID: 25732149 DOI: 10.2174/1566524015666150303003028] [Citation(s) in RCA: 327] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 12/20/2014] [Accepted: 01/18/2015] [Indexed: 12/16/2022]
Abstract
Autism Spectrum Disorders (ASD) and Schizophrenia (SCZ) are cognitive disorders with complex genetic architectures but overlapping behavioral phenotypes, which suggests common pathway perturbations. Multiple lines of evidence implicate imbalances in excitatory and inhibitory activity (E/I imbalance) as a shared pathophysiological mechanism. Thus, understanding the molecular underpinnings of E/I imbalance may provide essential insight into the etiology of these disorders and may uncover novel targets for future drug discovery. Here, we review key genetic, physiological, neuropathological, functional, and pathway studies that suggest alterations to excitatory/inhibitory circuits are keys to ASD and SCZ pathogenesis.
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Affiliation(s)
| | - P Penzes
- Department of Physiology, Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, IL 60611, USA.
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41
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Larkin A, Chen MY, Kirszenblat L, Reinhard J, van Swinderen B, Claudianos C. Neurexin-1 regulates sleep and synaptic plasticity in Drosophila melanogaster. Eur J Neurosci 2015. [PMID: 26201245 DOI: 10.1111/ejn.13023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neurexins are cell adhesion molecules that are important for synaptic plasticity and homeostasis, although links to sleep have not yet been investigated. We examined the effects of neurexin-1 perturbation on sleep in Drosophila, showing that neurexin-1 nulls displayed fragmented sleep and altered circadian rhythm. Conversely, the over-expression of neurexin-1 could increase and consolidate night-time sleep. This was not solely due to developmental effects as it could be induced acutely in adulthood, and was coupled with evidence of synaptic growth. The timing of over-expression could differentially impact sleep patterns, with specific night-time effects. These results show that neurexin-1 was dynamically involved in synaptic plasticity and sleep in Drosophila. Neurexin-1 and a number of its binding partners have been repeatedly associated with mental health disorders, including autism spectrum disorders, schizophrenia and Tourette syndrome, all of which are also linked to altered sleep patterns. How and when plasticity-related proteins such as neurexin-1 function during sleep can provide vital information on the interaction between synaptic homeostasis and sleep, paving the way for more informed treatments of human disorders.
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Affiliation(s)
- Aoife Larkin
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Ming-Yu Chen
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Leonie Kirszenblat
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Judith Reinhard
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - Charles Claudianos
- Queensland Brain Institute, The University of Queensland, St Lucia, Qld, 4072, Australia.,School of Psychological Sciences, Faculty of Biomedical and Psychological Sciences, Monash University, Melbourne, Vic., Australia
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Abstract
A fundamental physical interaction exists across the synapse. It is mediated by synaptic adhesion molecules, and is among the earliest and most indispensable of molecular events occurring during synaptogenesis. The regulation of adhesion molecules and their interactions with other synaptic proteins likely affect not only on synapse formation but also on ongoing synaptic function. We review research on one major family of postsynaptic adhesion molecules, neuroligins, which bind to their presynaptic partner neurexin across the synaptic cleft. We move from a structural overview to the broad cellular and synaptic context of neuroligins, intermolecular interactions, and molecular modifications that occur within a synapse. Finally, we examine evidence concerning the physiological functions of neuroligin in a cell and highlight areas requiring further investigation.
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Affiliation(s)
- Michael A Bemben
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD 20892, USA; Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Seth L Shipman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Roger A Nicoll
- Departments of Cellular and Molecular Pharmacology and Physiology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD 20892, USA.
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43
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Proctor DT, Stotz SC, Scott LOM, de la Hoz CLR, Poon KWC, Stys PK, Colicos MA. Axo-glial communication through neurexin-neuroligin signaling regulates myelination and oligodendrocyte differentiation. Glia 2015; 63:2023-2039. [PMID: 26119281 DOI: 10.1002/glia.22875] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 05/25/2015] [Accepted: 06/02/2015] [Indexed: 12/13/2022]
Abstract
Axonal transsynaptic signaling between presynaptic neurexin (NX) and postsynaptic neuroligin (NL) is essential for many properties of synaptic connectivity. Here, we demonstrate the existence of a parallel axo-glial signaling pathway between axonal NX and oligodendritic (OL) NL3. We show that this pathway contributes to the regulation of myelinogenesis, the maintenance of established myelination, and the differentiation state of the OL using in vitro models. We first confirm that NL3 mRNA and protein are expressed in OLs and in OL precursors. We then show that OLs in culture form contacts with non-neuronal cells exogenously expressing NL3's binding partners NX1α or NX1β. Conversely, blocking axo-glial NX-NL3 signaling by saturating NX with exogenous soluble NL protein (NL-ECD) disrupts interactions between OLs and axons in both in vitro and ex vivo assays. Myelination by OLs is tied to their differentiation state, and we find that blocking NX-NL signaling with soluble NL protein also caused OL differentiation to stall at an immature stage. Moreover, in vitro knockdown of NL3 in OLs with siRNAs stalls their development and reduces branching complexity. Interestingly, inclusion of an autism related mutation in the NL blocking protein attenuates these effects; OLs differentiate and the dynamics of OL-axon signaling occur normally as this peptide does not disrupt NX-NL3 axo-glial interactions. Our findings provide evidence not only for a new pathway in axo-glial communication, they also potentially explain the correlation between altered white matter and autism. GLIA 2015;63:2023-2039.
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Affiliation(s)
- Dustin T Proctor
- Department of Physiology & Pharmacology, Faculty of Medicine, and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Stephanie C Stotz
- Department of Physiology & Pharmacology, Faculty of Medicine, and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Lucas O M Scott
- Department of Physiology & Pharmacology, Faculty of Medicine, and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Cristiane L R de la Hoz
- Department of Physiology & Pharmacology, Faculty of Medicine, and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Kelvin W C Poon
- Department of Clinical Neurosciences, Faculty of Medicine and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Peter K Stys
- Department of Clinical Neurosciences, Faculty of Medicine and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Michael A Colicos
- Department of Physiology & Pharmacology, Faculty of Medicine, and the Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
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44
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Li W, Kinch LN, Karplus PA, Grishin NV. ChSeq: A database of chameleon sequences. Protein Sci 2015; 24:1075-86. [PMID: 25970262 DOI: 10.1002/pro.2689] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/15/2015] [Accepted: 04/24/2015] [Indexed: 11/11/2022]
Abstract
Chameleon sequences (ChSeqs) refer to sequence strings of identical amino acids that can adopt different conformations in protein structures. Researchers have detected and studied ChSeqs to understand the interplay between local and global interactions in protein structure formation. The different secondary structures adopted by one ChSeq challenge sequence-based secondary structure predictors. With increasing numbers of available Protein Data Bank structures, we here identify a large set of ChSeqs ranging from 6 to 10 residues in length. The homologous ChSeqs discovered highlight the structural plasticity involved in biological function. When compared with previous studies, the set of unrelated ChSeqs found represents an about 20-fold increase in the number of detected sequences, as well as an increase in the longest ChSeq length from 8 to 10 residues. We applied secondary structure predictors on our ChSeqs and found that methods based on a sequence profile outperformed methods based on a single sequence. For the unrelated ChSeqs, the evolutionary information provided by the sequence profile typically allows successful prediction of the prevailing secondary structure adopted in each protein family. Our dataset will facilitate future studies of ChSeqs, as well as interpretations of the interplay between local and nonlocal interactions. A user-friendly web interface for this ChSeq database is available at prodata.swmed.edu/chseq.
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Affiliation(s)
- Wenlin Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
| | - Lisa N Kinch
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
| | - P Andrew Karplus
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, 97331
| | - Nick V Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, 75390-9050
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45
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Schreiner D, Simicevic J, Ahrné E, Schmidt A, Scheiffele P. Quantitative isoform-profiling of highly diversified recognition molecules. eLife 2015; 4:e07794. [PMID: 25985086 PMCID: PMC4489214 DOI: 10.7554/elife.07794] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/14/2015] [Indexed: 12/28/2022] Open
Abstract
Complex biological systems rely on cell surface cues that govern cellular self-recognition and selective interactions with appropriate partners. Molecular diversification of cell surface recognition molecules through DNA recombination and complex alternative splicing has emerged as an important principle for encoding such interactions. However, the lack of tools to specifically detect and quantify receptor protein isoforms is a major impediment to functional studies. We here developed a workflow for targeted mass spectrometry by selected reaction monitoring that permits quantitative assessment of highly diversified protein families. We apply this workflow to dissecting the molecular diversity of the neuronal neurexin receptors and uncover an alternative splicing-dependent recognition code for synaptic ligands. DOI:http://dx.doi.org/10.7554/eLife.07794.001 To create a protein, a gene is first copied to form an RNA molecule that contains regions known as introns and exons. Splicing removes the introns and joins the exons together to form a molecule of ‘messenger RNA’, which is translated into a protein. Over the course of evolution, many groups—or families—of proteins have expanded and diversified their roles. One way in which this can occur is through a process known as alternative splicing, in which different exons can be included or excluded to generate the final messenger RNA. In this way, a single gene can produce a number of different proteins. These closely related proteins are known as isoforms. The brain contains billions of neurons that communicate with one another across connections known as synapses. A family of proteins called neurexins helps neurons to form these synapses. Humans have three neurexin genes, which undergo extensive alternative splicing to produce thousands of protein isoforms. However, it is not known whether all of these isoforms are produced in neurons, as existing experimental techniques were not sensitive enough to easily distinguish one isoform from another. A technique known as ‘selected reaction monitoring’ (or SRM for short) has recently emerged as a promising way to identify proteins. This allows proteins containing specific sequences to be separated out for analysis, in contrast to existing techniques that test randomly selected protein samples, which will result in most isoforms being missed. Schreiner, Simicevic et al. have now developed SRM further and show that this technique can detect the identity and amount of the neurexin isoforms present at synapses, including those that are only produced in very small quantities. Using SRM, Schreiner, Simicevic et al. demonstrate that neurexin isoforms differ in how they interact with synaptic receptors. Thus, alternative splicing of neurexins underlies a ‘recognition code’ at neuronal synapses. In the future, this newly developed SRM method could be used to investigate isoforms in other protein families and tissues, and so may prove valuable for understanding how a wide range of cellular recognition processes work. DOI:http://dx.doi.org/10.7554/eLife.07794.002
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Affiliation(s)
| | | | - Erik Ahrné
- Biozentrum, University of Basel, Basel, Switzerland
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46
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Yamagata A, Yoshida T, Sato Y, Goto-Ito S, Uemura T, Maeda A, Shiroshima T, Iwasawa-Okamoto S, Mori H, Mishina M, Fukai S. Mechanisms of splicing-dependent trans-synaptic adhesion by PTPδ-IL1RAPL1/IL-1RAcP for synaptic differentiation. Nat Commun 2015; 6:6926. [PMID: 25908590 PMCID: PMC4423211 DOI: 10.1038/ncomms7926] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/16/2015] [Indexed: 01/07/2023] Open
Abstract
Synapse formation is triggered through trans-synaptic interaction between pairs of pre- and postsynaptic adhesion molecules, the specificity of which depends on splice inserts known as 'splice-insert signaling codes'. Receptor protein tyrosine phosphatase δ (PTPδ) can bidirectionally induce pre- and postsynaptic differentiation of neurons by trans-synaptically binding to interleukin-1 receptor accessory protein (IL-1RAcP) and IL-1RAcP-like-1 (IL1RAPL1) in a splicing-dependent manner. Here, we report crystal structures of PTPδ in complex with IL1RAPL1 and IL-1RAcP. The first immunoglobulin-like (Ig) domain of IL1RAPL1 directly recognizes the first splice insert, which is critical for binding to IL1RAPL1. The second splice insert functions as an adjustable linker that positions the Ig2 and Ig3 domains of PTPδ for simultaneously interacting with the Ig1 domain of IL1RAPL1 or IL-1RAcP. We further identified the IL1RAPL1-specific interaction, which appears coupled to the first-splice-insert-mediated interaction. Our results thus reveal the decoding mechanism of splice-insert signaling codes for synaptic differentiation induced by trans-synaptic adhesion between PTPδ and IL1RAPL1/IL-1RAcP.
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Affiliation(s)
- Atsushi Yamagata
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan,Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,PRESTO, JST, Saitama 332-0012, Japan,
| | - Yusuke Sato
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Sakurako Goto-Ito
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Takeshi Uemura
- CREST, JST, Saitama 332-0012, Japan,Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Nagano 390-8621, Japan,Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano 390-8621, Japan
| | - Asami Maeda
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoko Shiroshima
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Shiho Iwasawa-Okamoto
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan,PRESTO, JST, Saitama 332-0012, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,Brain Science Laboratory, The Research Organization of Science and Technology, Ritsumeikan University, Shiga 525-8577, Japan
| | - Shuya Fukai
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan,
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47
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Calahorro F, Holden-Dye L, O'Connor V. Analysis of splice variants for the C. elegans orthologue of human neuroligin reveals a developmentally regulated transcript. Gene Expr Patterns 2015; 17:69-78. [PMID: 25726726 DOI: 10.1016/j.gep.2015.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/17/2015] [Accepted: 02/19/2015] [Indexed: 11/20/2022]
Abstract
Neuroligins are synaptic adhesion molecules and important determinants of synaptic function. They are expressed at postsynaptic sites and involved in synaptic organization through key extracellular and intracellular protein interactions. They undergo trans-synaptic interaction with presynaptic neurexins. Distinct neuroligins use differences in their intracellular domains to selectively recruit synaptic scaffolds and this plays an important role in how they encode specialization of synaptic function. Several levels of regulation including gene expression, splicing, protein translation and processing regulate the expression of neuroligin function. We have used in silico and cDNA analyses to investigate the mRNA splicing of the Caenorhabditis elegans orthologue nlg-1. Transcript analysis highlights the potential for gene regulation with respect to both temporal expression and splicing. We found nlg-1 splice variants with all the predicted exons are a minor species relative to major splice variants lacking exons 13 and 14, or 14 alone. These major alternatively spliced variants change the intracellular domain of the gene product NLG-1. Interestingly, exon 14 encodes a cassette with two distinct potential functional domains. One is a polyproline SH3 binding domain and the other has homology to a region encoding the binding site for the scaffolding protein gephyrin in mammalian neuroligins. This suggests differential splicing impacts on NLG-1 competence to recruit intracellular binding partners. This may have developmental relevance as nlg-1 exon 14 containing transcripts are selectively expressed in L2-L3 larvae. These results highlight a developmental regulation of C. elegans nlg-1 that could play a key role in the assembly of synaptic protein complexes during the early stages of nervous system development.
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Affiliation(s)
- Fernando Calahorro
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK.
| | - Lindy Holden-Dye
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
| | - Vincent O'Connor
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton SO17 1BJ, UK
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48
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Abstract
The neurexin family of cell adhesion proteins consists of three members in
vertebrates and has homologs in several invertebrate species. In mammals, each
neurexin gene encodes an α-neurexin in which the extracellular portion is long,
and a β-neurexin in which the extracellular portion is short. As a result of
alternative splicing, both major isoforms can be transcribed in many variants,
contributing to distinct structural domains and variability. Neurexins act
predominantly at the presynaptic terminal in neurons and play essential roles in
neurotransmission and differentiation of synapses. Some of these functions require
the formation of trans-synaptic complexes with postsynaptic proteins such as
neuroligins, LRRTM proteins or cerebellin. In addition, rare mutations and
copy-number variations of human neurexin genes have been linked to autism and
schizophrenia, indicating that impairments of synaptic function sustained by
neurexins and their binding partners may be relevant to the pathomechanism of these
debilitating diseases.
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49
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Um JW, Kim KH, Park BS, Choi Y, Kim D, Kim CY, Kim SJ, Kim M, Ko JS, Lee SG, Choii G, Nam J, Heo WD, Kim E, Lee JO, Ko J, Kim HM. Structural basis for LAR-RPTP/Slitrk complex-mediated synaptic adhesion. Nat Commun 2014; 5:5423. [PMID: 25394468 DOI: 10.1038/ncomms6423] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 09/29/2014] [Indexed: 01/08/2023] Open
Abstract
Synaptic adhesion molecules orchestrate synaptogenesis. The presynaptic leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) regulate synapse development by interacting with postsynaptic Slit- and Trk-like family proteins (Slitrks), which harbour two extracellular leucine-rich repeats (LRR1 and LRR2). Here we identify the minimal regions of the LAR-RPTPs and Slitrks, LAR-RPTPs Ig1-3 and Slitrks LRR1, for their interaction and synaptogenic function. Subsequent crystallographic and structure-guided functional analyses reveal that the splicing inserts in LAR-RPTPs are key molecular determinants for Slitrk binding and synapse formation. Moreover, structural comparison of the two Slitrk1 LRRs reveal that unique properties on the concave surface of Slitrk1 LRR1 render its specific binding to LAR-RPTPs. Finally, we demonstrate that lateral interactions between adjacent trans-synaptic LAR-RPTPs/Slitrks complexes observed in crystal lattices are critical for Slitrk1-induced lateral assembly and synaptogenic activity. Thus, we propose a model in which Slitrks mediate synaptogenic functions through direct binding to LAR-RPTPs and the subsequent lateral assembly of LAR-RPTPs/Slitrks complexes.
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Affiliation(s)
- Ji Won Um
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Kee Hun Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Beom Seok Park
- Department of Biomedical Laboratory Science, College of Health Science, Eulji University, Seongnam 461-713, Korea
| | - Yeonsoo Choi
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Cha Yeon Kim
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Soo Jin Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Minhye Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Ji Seung Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Seong-Gyu Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Gayoung Choii
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Jungyong Nam
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Won Do Heo
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Eunjoon Kim
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Jie-Oh Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jaewon Ko
- 1] Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea [2] Department of Psychiatry, Yonsei University College of Medicine, Seoul 120-751, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
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50
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Reissner C, Stahn J, Breuer D, Klose M, Pohlentz G, Mormann M, Missler M. Dystroglycan binding to α-neurexin competes with neurexophilin-1 and neuroligin in the brain. J Biol Chem 2014; 289:27585-603. [PMID: 25157101 PMCID: PMC4183798 DOI: 10.1074/jbc.m114.595413] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
α-Neurexins (α-Nrxn) are mostly presynaptic cell surface molecules essential for neurotransmission that are linked to neuro-developmental disorders as autism or schizophrenia. Several interaction partners of α-Nrxn are identified that depend on alternative splicing, including neuroligins (Nlgn) and dystroglycan (αDAG). The trans-synaptic complex with Nlgn1 was extensively characterized and shown to partially mediate α-Nrxn function. However, the interactions of α-Nrxn with αDAG, neurexophilins (Nxph1) and Nlgn2, ligands that occur specifically at inhibitory synapses, are incompletely understood. Using site-directed mutagenesis, we demonstrate the exact binding epitopes of αDAG and Nxph1 on Nrxn1α and show that their binding is mutually exclusive. Identification of an unusual cysteine bridge pattern and complex type glycans in Nxph1 ensure binding to the second laminin/neurexin/sex hormone binding (LNS2) domain of Nrxn1α, but this association does not interfere with Nlgn binding at LNS6. αDAG, in contrast, interacts with both LNS2 and LNS6 domains without inserts in splice sites SS#2 or SS#4 mostly via LARGE (like-acetylglucosaminyltransferase)-dependent glycans attached to the mucin region. Unexpectedly, binding of αDAG at LNS2 prevents interaction of Nlgn at LNS6 with or without splice insert in SS#4, presumably by sterically hindering each other in the u-form conformation of α-Nrxn. Thus, expression of αDAG and Nxph1 together with alternative splicing in Nrxn1α may prevent or facilitate formation of distinct trans-synaptic Nrxn·Nlgn complexes, revealing an unanticipated way to contribute to the identity of synaptic subpopulations.
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Affiliation(s)
- Carsten Reissner
- From the Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Vesaliusweg 2-4, 48149 Münster, Germany
| | - Johanna Stahn
- From the Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Vesaliusweg 2-4, 48149 Münster, Germany
| | - Dorothee Breuer
- From the Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Vesaliusweg 2-4, 48149 Münster, Germany
| | - Martin Klose
- From the Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Vesaliusweg 2-4, 48149 Münster, Germany
| | - Gottfried Pohlentz
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University, Robert-Koch Strasse 31, 48149 Münster, Germany, and
| | - Michael Mormann
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University, Robert-Koch Strasse 31, 48149 Münster, Germany, and
| | - Markus Missler
- From the Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Vesaliusweg 2-4, 48149 Münster, Germany, Cluster of Excellence EXC 1003, Cells in Motion, 48149 Münster, Germany
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