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Nowacka A, Getz AM, Bessa-Neto D, Choquet D. Activity-dependent diffusion trapping of AMPA receptors as a key step for expression of early LTP. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230220. [PMID: 38853553 PMCID: PMC11343219 DOI: 10.1098/rstb.2023.0220] [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: 02/24/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 06/11/2024] Open
Abstract
This review focuses on the activity-dependent diffusion trapping of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) as a crucial mechanism for the expression of early long-term potentiation (LTP), a process central to learning and memory. Despite decades of research, the precise mechanisms by which LTP induction leads to an increase in AMPAR responses at synapses have been elusive. We review the different hypotheses that have been put forward to explain the increased AMPAR responsiveness during LTP. We discuss the dynamic nature of AMPAR complexes, including their constant turnover and activity-dependent modifications that affect their synaptic accumulation. We highlight a hypothesis suggesting that AMPARs are diffusively trapped at synapses through activity-dependent interactions with protein-based binding slots in the post-synaptic density (PSD), offering a potential explanation for the increased synaptic strength during LTP. Furthermore, we outline the challenges still to be addressed before we fully understand the functional roles and molecular mechanisms of AMPAR dynamic nanoscale organization in LTP. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Agata Nowacka
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, BordeauxF-33000, France
| | - Angela M. Getz
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, BordeauxF-33000, France
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, BordeauxF-33000, France
| | - Diogo Bessa-Neto
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, BordeauxF-33000, France
| | - Daniel Choquet
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, BordeauxF-33000, France
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, BordeauxF-33000, France
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2
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Gogou C, Beugelink JW, Frias CP, Kresik L, Jaroszynska N, Drescher U, Janssen BJC, Hindges R, Meijer DH. Alternative splicing controls teneurin-3 compact dimer formation for neuronal recognition. Nat Commun 2024; 15:3648. [PMID: 38684645 PMCID: PMC11058771 DOI: 10.1038/s41467-024-47763-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 04/11/2024] [Indexed: 05/02/2024] Open
Abstract
Neuronal network formation is facilitated by recognition between synaptic cell adhesion molecules at the cell surface. Alternative splicing of cell adhesion molecules provides additional specificity in forming neuronal connections. For the teneurin family of cell adhesion molecules, alternative splicing of the EGF-repeats and NHL domain controls synaptic protein-protein interactions. Here we present cryo-EM structures of the compact dimeric ectodomain of two teneurin-3 isoforms that harbour the splice insert in the EGF-repeats. This dimer is stabilised by an EGF8-ABD contact between subunits. Cryo-EM reconstructions of all four splice variants, together with SAXS and negative stain EM, reveal compacted dimers for each, with variant-specific dimeric arrangements. This results in specific trans-cellular interactions, as tested in cell clustering and stripe assays. The compact conformations provide a structural basis for teneurin homo- and heterophilic interactions. Altogether, our findings demonstrate how alternative splicing results in rearrangements of the dimeric subunits, influencing neuronal recognition and likely circuit wiring.
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Affiliation(s)
- Christos Gogou
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, van der Maasweg 9, Delft, the Netherlands
| | - J Wouter Beugelink
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht, the Netherlands
| | - Cátia P Frias
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, van der Maasweg 9, Delft, the Netherlands
| | - Leanid Kresik
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, van der Maasweg 9, Delft, the Netherlands
| | - Natalia Jaroszynska
- Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
| | - Uwe Drescher
- Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Bert J C Janssen
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Universiteitsweg 99, Utrecht, the Netherlands
| | - Robert Hindges
- Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Dimphna H Meijer
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, van der Maasweg 9, Delft, the Netherlands.
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3
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Matsui Y, Imai A, Izumi H, Yasumura M, Makino T, Shimizu T, Sato M, Mori H, Yoshida T. Cancer-associated point mutations within the extracellular domain of PTPRD affect protein stability and HSPG interaction. FASEB J 2024; 38:e23609. [PMID: 38593345 DOI: 10.1096/fj.202302279rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 03/12/2024] [Accepted: 03/29/2024] [Indexed: 04/11/2024]
Abstract
PTPRD, a well-established tumor suppressor gene, encodes the protein tyrosine phosphatase-type D. This protein consists of three immunoglobulin-like (Ig) domains, four to eight fibronectin type 3 (FN) domains, a single transmembrane segment, and two cytoplasmic tandem tyrosine phosphatase domains. PTPRD is known to harbor various cancer-associated point mutations. While it is assumed that PTPRD regulates cellular functions as a tumor suppressor through the tyrosine phosphatase activity in the intracellular region, the function of its extracellular domain (ECD) in cancer is not well understood. In this study, we systematically examined the impact of 92 cancer-associated point mutations within the ECD. We found that 69.6% (64 out of 92) of these mutations suppressed total protein expression and/or plasma membrane localization. Notably, almost all mutations (20 out of 21) within the region between the last FN domain and transmembrane segment affected protein expression and/or localization, highlighting the importance of this region for protein stability. We further found that some mutations within the Ig domains adjacent to the glycosaminoglycan-binding pocket enhanced PTPRD's binding ability to heparan sulfate proteoglycans (HSPGs). This interaction is proposed to suppress phosphatase activity. Our findings therefore suggest that HSPG-mediated attenuation of phosphatase activity may be involved in tumorigenic processes through PTPRD dysregulation.
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Affiliation(s)
- Yu Matsui
- Department of Dermatology, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Ayako Imai
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Hironori Izumi
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Misato Yasumura
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
- Division of Developmental Neuroscience, United Graduate School of Child Development (UGSCD), Osaka University, Osaka, Japan
| | - Teruhiko Makino
- Department of Dermatology, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Tadamichi Shimizu
- Department of Dermatology, Faculty of Medicine, University of Toyama, Toyama, Japan
| | - Makoto Sato
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
- Division of Developmental Neuroscience, United Graduate School of Child Development (UGSCD), Osaka University, Osaka, 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
| | - 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
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4
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Han KA, Yoon TH, Kim J, Lee J, Lee JY, Jang G, Um JW, Kim JK, Ko J. Specification of neural circuit architecture shaped by context-dependent patterned LAR-RPTP microexons. Nat Commun 2024; 15:1624. [PMID: 38388459 PMCID: PMC10883964 DOI: 10.1038/s41467-024-45695-0] [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: 07/13/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
LAR-RPTPs are evolutionarily conserved presynaptic cell-adhesion molecules that orchestrate multifarious synaptic adhesion pathways. Extensive alternative splicing of LAR-RPTP mRNAs may produce innumerable LAR-RPTP isoforms that act as regulatory "codes" for determining the identity and strength of specific synapse signaling. However, no direct evidence for this hypothesis exists. Here, using targeted RNA sequencing, we detected LAR-RPTP mRNAs in diverse cell types across adult male mouse brain areas. We found pronounced cell-type-specific patterns of two microexons, meA and meB, in Ptprd mRNAs. Moreover, diverse neural circuits targeting the same neuronal populations were dictated by the expression of different Ptprd variants with distinct inclusion patterns of microexons. Furthermore, conditional ablation of Ptprd meA+ variants at presynaptic loci of distinct hippocampal circuits impaired distinct modes of synaptic transmission and objection-location memory. Activity-triggered alterations of the presynaptic Ptprd meA code in subicular neurons mediates NMDA receptor-mediated postsynaptic responses in CA1 neurons and objection-location memory. Our data provide the evidence of cell-type- and/or circuit-specific expression patterns in vivo and physiological functions of LAR-RPTP microexons that are dynamically regulated.
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Affiliation(s)
- Kyung Ah Han
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Taek-Han Yoon
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jinhu Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jusung Lee
- Department of New Biology, DGIST, Daegu, 42988, Korea
| | - Ju Yeon Lee
- Korea Basic Science Institute, Research Center for Bioconvergence Analysis, Cheongju, 28119, Korea
| | - Gyubin Jang
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Jong Kyoung Kim
- Department of New Biology, DGIST, Daegu, 42988, Korea
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea.
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea.
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5
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Gu YH, Wang J, Lu WC, Cheng Y, Tao R, Zhang SJ, Xu T, Zhai KW, Luo SX, Xin WJ. POU2F1/DNMT3a Pathway Participates in Neuropathic Pain by Hypermethylation-Mediated LRFN4 Downregulation Following Oxaliplatin Treatment. Neurochem Res 2023; 48:3652-3664. [PMID: 37592110 DOI: 10.1007/s11064-023-04011-w] [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: 06/07/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/19/2023]
Abstract
Evidence demonstrates that DNA methylation is associated with the occurrence and development of various neurological diseases. However, the potential target genes undergoing DNA methylation, as well as their involvement in the chemotherapy drug oxaliplatin-induced neuropathic pain, are still unclear. Here, Lrfn4, which showed hypermethylation in the promoter regions, was screened from the SRA methylation database (PRJNA587622) following oxaliplatin treatment. MeDIP and qPCR assays identified that oxaliplatin treatment increased the methylation in Lrfn4 promoter region and decreased the expression of LRFN4 in the spinal dorsal horn. The assays with gain and loss of LRFN4 function demonstrated that LRFN4 downregulation in spinal dorsal horn contributed to the oxaliplatin-induced mechanical allodynia and cold hyperalgesia. Moreover, oxaliplatin treatment increased the DNA methyltransferases DNMT3a expression and the interaction between DNMT3a and Lrfn4 promoter, while inhibition of DNMT3a prevented the downregulation of LRFN4a induced by oxaliplatin. We also observed that the transcriptional factor POU2F1 can bind to the predicted sites in DNMT3a promoter region, oxaliplatin treatment upregulated the expression of transcriptional factor POU2F1 in dorsal horn neurons. Intrathecal injection of POU2F1 siRNA prevented the DNMT3a upregulation and the LRFN4 downregulation induced by oxaliplatin. Additionally, intrathecal injection of DNMT3a siRNA or POU2F1 siRNA alleviated the mechanical allodynia induced by oxaliplatin. These findings suggested that transcription factor POU2F1 upregulated the expression of DNMT3a, which subsequently decreased LRFN4 expression through hypermethylation modification in spinal dorsal horn, thereby mediating neuropathic pain following oxaliplatin treatment.
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Affiliation(s)
- Yan-Hui Gu
- Department of General Surgery, Cancer Hospital of Zhengzhou University, 127 Dongming Rd, Zhengzhou, China
- Guangdong Province Key Laboratory of Brain Function and Disease and Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Jing Wang
- Guangdong Province Key Laboratory of Brain Function and Disease and Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510120, China
- Department of Pain Management, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Wei-Cheng Lu
- State Key Laboratory of Oncology in Southern China, Department of Anesthesiology, Collaborative Innovation for Cancer Medicine, Sun Yat- sen University Cancer Center, Guangzhou, China
| | - Yong Cheng
- Department of General Surgery, Cancer Hospital of Zhengzhou University, 127 Dongming Rd, Zhengzhou, China
| | - Rong Tao
- Department of Pain Management, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Shi-Jia Zhang
- Department of General Surgery, Cancer Hospital of Zhengzhou University, 127 Dongming Rd, Zhengzhou, China
| | - Ting Xu
- Guangdong Province Key Laboratory of Brain Function and Disease and Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Ke-Wei Zhai
- Department of General Surgery, Cancer Hospital of Zhengzhou University, 127 Dongming Rd, Zhengzhou, China
| | - Su-Xia Luo
- Department of General Surgery, Cancer Hospital of Zhengzhou University, 127 Dongming Rd, Zhengzhou, China.
| | - Wen-Jun Xin
- Guangdong Province Key Laboratory of Brain Function and Disease and Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510120, China.
- Zhongshan Medical School, Sun Yat-sen University, Zhongshan Rd. 2, Guangzhou, China.
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6
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Connor SA, Siddiqui TJ. Synapse organizers as molecular codes for synaptic plasticity. Trends Neurosci 2023; 46:971-985. [PMID: 37652840 DOI: 10.1016/j.tins.2023.08.001] [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: 05/21/2023] [Revised: 07/13/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Synapse organizing proteins are multifaceted molecules that coordinate the complex processes of brain development and plasticity at the level of individual synapses. Their importance is demonstrated by the major brain disorders that emerge when their function is compromised. The mechanisms whereby the various families of organizers govern synapses are diverse, but converge on the structure, function, and plasticity of synapses. Therefore, synapse organizers regulate how synapses adapt to ongoing activity, a process central for determining the developmental trajectory of the brain and critical to all forms of cognition. Here, we explore how synapse organizers set the conditions for synaptic plasticity and the associated molecular events, which eventually link to behavioral features of neurodevelopmental and neuropsychiatric disorders. We also propose central questions on how synapse organizers influence network function through integrating nanoscale and circuit-level organization of the brain.
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Affiliation(s)
- Steven A Connor
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Tabrez J Siddiqui
- PrairieNeuro Research Centre, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, MB R3E 0Z3, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; The Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada; Program in Biomedical Engineering, University of Manitoba, Winnipeg, MB, Canada.
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7
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Sclip A, Südhof TC. Combinatorial expression of neurexins and LAR-type phosphotyrosine phosphatase receptors instructs assembly of a cerebellar circuit. Nat Commun 2023; 14:4976. [PMID: 37591863 PMCID: PMC10435579 DOI: 10.1038/s41467-023-40526-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023] Open
Abstract
Synaptic adhesion molecules (SAMs) shape the structural and functional properties of synapses and thereby control the information processing power of neural circuits. SAMs are broadly expressed in the brain, suggesting that they may instruct synapse formation and specification via a combinatorial logic. Here, we generate sextuple conditional knockout mice targeting all members of the two major families of presynaptic SAMs, Neurexins and leukocyte common antigen-related-type receptor phospho-tyrosine phosphatases (LAR-PTPRs), which together account for the majority of known trans-synaptic complexes. Using synapses formed by cerebellar Purkinje cells onto deep cerebellar nuclei as a model system, we confirm that Neurexins and LAR-PTPRs themselves are not essential for synapse assembly. The combinatorial deletion of both neurexins and LAR-PTPRs, however, decreases Purkinje-cell synapses on deep cerebellar nuclei, the major output pathway of cerebellar circuits. Consistent with this finding, combined but not separate deletions of neurexins and LAR-PTPRs impair motor behaviors. Thus, Neurexins and LAR-PTPRs are together required for the assembly of a functional cerebellar circuit.
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Affiliation(s)
- Alessandra Sclip
- Department of Cellular and Molecular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Thomas C Südhof
- Department of Cellular and Molecular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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8
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Karki S, Kajander T. Crystallization and low-resolution structure solution of the SALM3-PTPσ synaptic adhesion complex. Acta Crystallogr F Struct Biol Commun 2022; 78:39-44. [PMID: 34981774 PMCID: PMC8725006 DOI: 10.1107/s2053230x21012905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/03/2021] [Indexed: 01/03/2023] Open
Abstract
Synaptic adhesion molecules are major organizers of the neuronal network and play a crucial role in the regulation of synapse development and maintenance in the brain. Synaptic adhesion-like molecules (SALMs) and leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-PTPs) are adhesion protein families with established synaptic function. Dysfunction of several synaptic adhesion molecules has been linked to cognitive disorders such as autism spectrum disorders and schizophrenia. A recent study of the binding and complex structure of SALM3 and PTPσ using small-angle X-ray scattering revealed a 2:2 complex similar to that observed for the interaction of human SALM5 and PTPδ. However, the molecular structure of the SALM3-PTPσ complex remains to be determined beyond the small-angle X-ray scattering model. Here, the expression, purification, crystallization and initial 6.5 Å resolution structure of the mouse SALM3-PTPσ complex are reported, which further verifies the formation of a 2:2 trans-heterotetrameric complex similar to the crystal structure of human SALM5-PTPδ and validates the architecture of the previously reported small-angle scattering-based solution structure of the SALM3-PTPσ complex. Details of the protein expression and purification, crystal optimization trials, and the initial structure solution and data analysis are provided.
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Affiliation(s)
- Sudeep Karki
- Institute of Biotechnology, Helsinki Institute of Life Sciences, University of Helsinki, Viikinkaari 1, 00014 Helsinki, Finland
| | - Tommi Kajander
- Institute of Biotechnology, Helsinki Institute of Life Sciences, University of Helsinki, Viikinkaari 1, 00014 Helsinki, Finland,Correspondence e-mail:
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9
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Cornejo F, Cortés BI, Findlay GM, Cancino GI. LAR Receptor Tyrosine Phosphatase Family in Healthy and Diseased Brain. Front Cell Dev Biol 2021; 9:659951. [PMID: 34966732 PMCID: PMC8711739 DOI: 10.3389/fcell.2021.659951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 11/17/2021] [Indexed: 11/23/2022] Open
Abstract
Protein phosphatases are major regulators of signal transduction and they are involved in key cellular mechanisms such as proliferation, differentiation, and cell survival. Here we focus on one class of protein phosphatases, the type IIA Receptor-type Protein Tyrosine Phosphatases (RPTPs), or LAR-RPTP subfamily. In the last decade, LAR-RPTPs have been demonstrated to have great importance in neurobiology, from neurodevelopment to brain disorders. In vertebrates, the LAR-RPTP subfamily is composed of three members: PTPRF (LAR), PTPRD (PTPδ) and PTPRS (PTPσ), and all participate in several brain functions. In this review we describe the structure and proteolytic processing of the LAR-RPTP subfamily, their alternative splicing and enzymatic regulation. Also, we review the role of the LAR-RPTP subfamily in neural function such as dendrite and axon growth and guidance, synapse formation and differentiation, their participation in synaptic activity, and in brain development, discussing controversial findings and commenting on the most recent studies in the field. Finally, we discuss the clinical outcomes of LAR-RPTP mutations, which are associated with several brain disorders.
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Affiliation(s)
- Francisca Cornejo
- Center for Integrative Biology, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Bastián I Cortés
- Center for Integrative Biology, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Greg M Findlay
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Gonzalo I Cancino
- Center for Integrative Biology, Facultad de Ciencias, Universidad Mayor, Santiago, Chile.,Escuela de Biotecnología, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
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10
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Lie E, Yeo Y, Lee EJ, Shin W, Kim K, Han KA, Yang E, Choi TY, Bae M, Lee S, Um SM, Choi SY, Kim H, Ko J, Kim E. SALM4 negatively regulates NMDA receptor function and fear memory consolidation. Commun Biol 2021; 4:1138. [PMID: 34588597 PMCID: PMC8481232 DOI: 10.1038/s42003-021-02656-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 09/09/2021] [Indexed: 02/08/2023] Open
Abstract
Many synaptic adhesion molecules positively regulate synapse development and function, but relatively little is known about negative regulation. SALM4/Lrfn3 (synaptic adhesion-like molecule 4/leucine rich repeat and fibronectin type III domain containing 3) inhibits synapse development by suppressing other SALM family proteins, but whether SALM4 also inhibits synaptic function and specific behaviors remains unclear. Here we show that SALM4-knockout (Lrfn3-/-) male mice display enhanced contextual fear memory consolidation (7-day post-training) but not acquisition or 1-day retention, and exhibit normal cued fear, spatial, and object-recognition memory. The Lrfn3-/- hippocampus show increased currents of GluN2B-containing N-methyl-D-aspartate (NMDA) receptors (GluN2B-NMDARs), but not α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors (AMPARs), which requires the presynaptic receptor tyrosine phosphatase PTPσ. Chronic treatment of Lrfn3-/- mice with fluoxetine, a selective serotonin reuptake inhibitor used to treat excessive fear memory that directly inhibits GluN2B-NMDARs, normalizes NMDAR function and contextual fear memory consolidation in Lrfn3-/- mice, although the GluN2B-specific NMDAR antagonist ifenprodil was not sufficient to reverse the enhanced fear memory consolidation. These results suggest that SALM4 suppresses excessive GluN2B-NMDAR (not AMPAR) function and fear memory consolidation (not acquisition).
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Affiliation(s)
- Eunkyung Lie
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea ,grid.255168.d0000 0001 0671 5021Department of Chemistry, Dongguk University, Seoul, 04620 Korea
| | - Yeji Yeo
- grid.37172.300000 0001 2292 0500Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141 Korea
| | - Eun-Jae Lee
- grid.267370.70000 0004 0533 4667Department of Neurology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, 05505 Korea
| | - Wangyong Shin
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Kyungdeok Kim
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Kyung Ah Han
- grid.417736.00000 0004 0438 6721Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988 Korea
| | - Esther Yang
- grid.222754.40000 0001 0840 2678Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841 Korea
| | - Tae-Yong Choi
- grid.31501.360000 0004 0470 5905Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080 Korea
| | - Mihyun Bae
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Suho Lee
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Seung Min Um
- grid.37172.300000 0001 2292 0500Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141 Korea
| | - Se-Young Choi
- grid.31501.360000 0004 0470 5905Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080 Korea
| | - Hyun Kim
- grid.222754.40000 0001 0840 2678Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841 Korea
| | - Jaewon Ko
- grid.417736.00000 0004 0438 6721Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988 Korea
| | - Eunjoon Kim
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea ,grid.267370.70000 0004 0533 4667Department of Neurology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, 05505 Korea
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11
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Lesnikova A, Casarotto P, Moliner R, Fred SM, Biojone C, Castrén E. Perineuronal Net Receptor PTPσ Regulates Retention of Memories. Front Synaptic Neurosci 2021; 13:672475. [PMID: 34366821 PMCID: PMC8339997 DOI: 10.3389/fnsyn.2021.672475] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/25/2021] [Indexed: 12/29/2022] Open
Abstract
Perineuronal nets (PNNs) have an important physiological role in the retention of learning by restricting cognitive flexibility. Their deposition peaks after developmental periods of intensive learning, usually in late childhood, and they help in long-term preservation of newly acquired skills and information. Modulation of PNN function by various techniques enhances plasticity and regulates the retention of memories, which may be beneficial when memory persistence entails negative symptoms such as post-traumatic stress disorder (PTSD). In this study, we investigated the role of PTPσ [receptor-type tyrosine-protein phosphatase S, a phosphatase that is activated by binding of chondroitin sulfate proteoglycans (CSPGs) from PNNs] in retention of memories using Novel Object Recognition and Fear Conditioning models. We observed that mice haploinsufficient for PTPRS gene (PTPσ+/–), although having improved short-term object recognition memory, display impaired long-term memory in both Novel Object Recognition and Fear Conditioning paradigm, as compared to WT littermates. However, PTPσ+/– mice did not show any differences in behavioral tests that do not heavily rely on cognitive flexibility, such as Elevated Plus Maze, Open Field, Marble Burying, and Forced Swimming Test. Since PTPσ has been shown to interact with and dephosphorylate TRKB, we investigated activation of this receptor and its downstream pathways in limbic areas known to be associated with memory. We found that phosphorylation of TRKB and PLCγ are increased in the hippocampus, prefrontal cortex, and amygdaloid complex of PTPσ+/– mice, but other TRKB-mediated signaling pathways are not affected. Our data suggest that PTPσ downregulation promotes TRKB phosphorylation in different brain areas, improves short-term memory performance but disrupts long-term memory retention in the tested animal models. Inhibition of PTPσ or disruption of PNN-PTPσ-TRKB complex might be a potential target for disorders where negative modulation of the acquired memories can be beneficial.
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Affiliation(s)
| | - Plinio Casarotto
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Rafael Moliner
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Senem Merve Fred
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Caroline Biojone
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Eero Castrén
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
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12
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Type IIa RPTPs and Glycans: Roles in Axon Regeneration and Synaptogenesis. Int J Mol Sci 2021; 22:ijms22115524. [PMID: 34073798 PMCID: PMC8197235 DOI: 10.3390/ijms22115524] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 02/06/2023] Open
Abstract
Type IIa receptor tyrosine phosphatases (RPTPs) play pivotal roles in neuronal network formation. It is emerging that the interactions of RPTPs with glycans, i.e., chondroitin sulfate (CS) and heparan sulfate (HS), are critical for their functions. We highlight here the significance of these interactions in axon regeneration and synaptogenesis. For example, PTPσ, a member of type IIa RPTPs, on axon terminals is monomerized and activated by the extracellular CS deposited in neural injuries, dephosphorylates cortactin, disrupts autophagy flux, and consequently inhibits axon regeneration. In contrast, HS induces PTPσ oligomerization, suppresses PTPσ phosphatase activity, and promotes axon regeneration. PTPσ also serves as an organizer of excitatory synapses. PTPσ and neurexin bind one another on presynapses and further bind to postsynaptic leucine-rich repeat transmembrane protein 4 (LRRTM4). Neurexin is now known as a heparan sulfate proteoglycan (HSPG), and its HS is essential for the binding between these three molecules. Another HSPG, glypican 4, binds to presynaptic PTPσ and postsynaptic LRRTM4 in an HS-dependent manner. Type IIa RPTPs are also involved in the formation of excitatory and inhibitory synapses by heterophilic binding to a variety of postsynaptic partners. We also discuss the important issue of possible mechanisms coordinating axon extension and synapse formation.
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13
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Wojtowicz WM, Vielmetter J, Fernandes RA, Siepe DH, Eastman CL, Chisholm GB, Cox S, Klock H, Anderson PW, Rue SM, Miller JJ, Glaser SM, Bragstad ML, Vance J, Lam AW, Lesley SA, Zinn K, Garcia KC. A Human IgSF Cell-Surface Interactome Reveals a Complex Network of Protein-Protein Interactions. Cell 2021; 182:1027-1043.e17. [PMID: 32822567 PMCID: PMC7440162 DOI: 10.1016/j.cell.2020.07.025] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/19/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022]
Abstract
Cell-surface protein-protein interactions (PPIs) mediate cell-cell communication, recognition, and responses. We executed an interactome screen of 564 human cell-surface and secreted proteins, most of which are immunoglobulin superfamily (IgSF) proteins, using a high-throughput, automated ELISA-based screening platform employing a pooled-protein strategy to test all 318,096 PPI combinations. Screen results, augmented by phylogenetic homology analysis, revealed ∼380 previously unreported PPIs. We validated a subset using surface plasmon resonance and cell binding assays. Observed PPIs reveal a large and complex network of interactions both within and across biological systems. We identified new PPIs for receptors with well-characterized ligands and binding partners for “orphan” receptors. New PPIs include proteins expressed on multiple cell types and involved in diverse processes including immune and nervous system development and function, differentiation/proliferation, metabolism, vascularization, and reproduction. These PPIs provide a resource for further biological investigation into their functional relevance and may offer new therapeutic drug targets. Human IgSF interactome reveals complex network of cell-surface protein interactions Phylogenetic homology analysis predicts protein-protein interactions ∼380 previously unknown protein-protein interactions identified Deorphanization of receptors and new binding partners for well-studied receptors
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Affiliation(s)
- Woj M Wojtowicz
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Jost Vielmetter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ricardo A Fernandes
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Dirk H Siepe
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Catharine L Eastman
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gregory B Chisholm
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sarah Cox
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Heath Klock
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Paul W Anderson
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Sarah M Rue
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Jessica J Miller
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Scott M Glaser
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Melisa L Bragstad
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Julie Vance
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Annie W Lam
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Scott A Lesley
- The Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Kai Zinn
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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14
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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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15
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Kim HY, Um JW, Ko J. Proper synaptic adhesion signaling in the control of neural circuit architecture and brain function. Prog Neurobiol 2021; 200:101983. [PMID: 33422662 DOI: 10.1016/j.pneurobio.2020.101983] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022]
Abstract
Trans-synaptic cell-adhesion molecules are critical for governing various stages of synapse development and specifying neural circuit properties via the formation of multifarious signaling pathways. Recent studies have pinpointed the putative roles of trans-synaptic cell-adhesion molecules in mediating various cognitive functions. Here, we review the literature on the roles of a diverse group of central synaptic organizers, including neurexins (Nrxns), leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs), and their associated binding proteins, in regulating properties of specific type of synapses and neural circuits. In addition, we highlight the findings that aberrant synaptic adhesion signaling leads to alterations in the structures, transmission, and plasticity of specific synapses across diverse brain areas. These results seem to suggest that proper trans-synaptic signaling pathways by Nrxns, LAR-RPTPs, and their interacting network is likely to constitute central molecular complexes that form the basis for cognitive functions, and that these complexes are heterogeneously and complexly disrupted in many neuropsychiatric and neurodevelopmental disorders.
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Affiliation(s)
- Hee Young Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea; Core Protein Resources Center, DGIST, Daegu, 42988, South Korea.
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea.
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16
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Fukai S, Yoshida T. Roles of type IIa receptor protein tyrosine phosphatases as synaptic organizers. FEBS J 2020; 288:6913-6926. [PMID: 33301645 DOI: 10.1111/febs.15666] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/26/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022]
Abstract
Neurons establish circuits for brain functions such as cognition, emotion, learning, and memory. Their connections are mediated by synapses, which are specialized cell-cell adhesions responsible for neuronal signal transmission. During neurodevelopment, synapse formation is triggered by interactions of cell adhesion molecules termed synaptic organizers or synapse organizers. Type IIa receptor protein tyrosine phosphatases (IIa RPTPs; also known as leukocyte common antigen-related receptor tyrosine phosphatases or LAR-RPTPs) play important roles in axon guidance and neurite extension, and also serve as presynaptic organizers. IIa RPTPs transsynaptically interact with multiple sets of postsynaptic organizers, mostly in a splicing-dependent fashion. Here, we review and update research progress on IIa RPTPs, particularly regarding their functional roles in vivo demonstrated using conditional knockout approach and structural insights into their extracellular and intracellular molecular interactions revealed by crystallography and other biophysical techniques. Future directions in the research field of IIa RPTPs are also discussed, including recent findings of the molecular assembly mechanism underlying the formation of synapse-specific nanostructures essential for synaptic functions.
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Affiliation(s)
- Shuya Fukai
- Department of Chemistry, Graduate School of Science, Kyoto University, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
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17
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Yang X. Chondroitin sulfate proteoglycans: key modulators of neuronal plasticity, long-term memory, neurodegenerative, and psychiatric disorders. Rev Neurosci 2020; 31:555-568. [PMID: 32126020 DOI: 10.1515/revneuro-2019-0117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 01/02/2020] [Indexed: 12/19/2022]
Abstract
The chondroitin sulfate proteoglycans (CSPGs) are large groups of heterogenous proteoglycans that are mainly expressed by reactive astrocytes in the central nervous system (CNS). They share similar core proteins and are post-transcriptionally modified by chondroitin sulfate glycosaminoglycans. CSPGs are the major components of the perineuronal nets (PNN) that regulate the opening and closure of the critical period. Mounting reports have documented the crucial roles of CSPGs in restricting neuronal plasticity, axonal growth, and pathfinding during development as well as axonal regeneration after CNS injury. Moreover, CSPGs and PNNs modulate long-term memory, which impairments frequently happened in several neurodegenerative and psychiatric disorders. This review will shortly introduce the expression patterns of CSPGs during development and after injury, the PNNs constitutions, the roles of CSPGs and PNNs in axonal regrowth, discuss the most recently identified roles of CSPGs and PNNs in mediating long-term memory and their correlation with brain disorders, and finally, propose a short perspective of future investigations. Hopefully, further explorations may validate the therapeutic potentials of PNNs and CSPGs.
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Affiliation(s)
- Xin Yang
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, P.R. China
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18
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Karki S, Shkumatov AV, Bae S, Kim H, Ko J, Kajander T. Structural basis of SALM3 dimerization and synaptic adhesion complex formation with PTPσ. Sci Rep 2020; 10:11557. [PMID: 32665594 PMCID: PMC7360590 DOI: 10.1038/s41598-020-68502-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/26/2020] [Indexed: 01/18/2023] Open
Abstract
Synaptic adhesion molecules play an important role in the formation, maintenance and refinement of neuronal connectivity. Recently, several leucine rich repeat (LRR) domain containing neuronal adhesion molecules have been characterized including netrin G-ligands, SLITRKs and the synaptic adhesion-like molecules (SALMs). Dysregulation of these adhesion molecules have been genetically and functionally linked to various neurological disorders. Here we investigated the molecular structure and mechanism of ligand interactions for the postsynaptic SALM3 adhesion protein with its presynaptic ligand, receptor protein tyrosine phosphatase σ (PTPσ). We solved the crystal structure of the dimerized LRR domain of SALM3, revealing the conserved structural features and mechanism of dimerization. Furthermore, we determined the complex structure of SALM3 with PTPσ using small angle X-ray scattering, revealing a 2:2 complex similar to that observed for SALM5. Solution studies unraveled additional flexibility for the complex structure, but validated the uniform mode of action for SALM3 and SALM5 to promote synapse formation. The relevance of the key interface residues was further confirmed by mutational analysis with cellular binding assays and artificial synapse formation assays. Collectively, our results suggest that SALM3 dimerization is a pre-requisite for the SALM3-PTPσ complex to exert synaptogenic activity.
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Affiliation(s)
- Sudeep Karki
- Institute of Biotechnology, University of Helsinki, Viikinkaari 1, PO Box 65, 00014, Helsinki, Finland
| | - Alexander V Shkumatov
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050, Brussels, Belgium.,VIB-VUB Center for Structural Biology, 1050, Brussels, Belgium
| | - Sungwon Bae
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Hyeonho Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Tommi Kajander
- Institute of Biotechnology, University of Helsinki, Viikinkaari 1, PO Box 65, 00014, Helsinki, Finland.
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19
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Ray TA, Cochran K, Kozlowski C, Wang J, Alexander G, Cady MA, Spencer WJ, Ruzycki PA, Clark BS, Laeremans A, He MX, Wang X, Park E, Hao Y, Iannaccone A, Hu G, Fedrigo O, Skiba NP, Arshavsky VY, Kay JN. Comprehensive identification of mRNA isoforms reveals the diversity of neural cell-surface molecules with roles in retinal development and disease. Nat Commun 2020; 11:3328. [PMID: 32620864 PMCID: PMC7335077 DOI: 10.1038/s41467-020-17009-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 05/30/2020] [Indexed: 02/08/2023] Open
Abstract
Genes encoding cell-surface proteins control nervous system development and are implicated in neurological disorders. These genes produce alternative mRNA isoforms which remain poorly characterized, impeding understanding of how disease-associated mutations cause pathology. Here we introduce a strategy to define complete portfolios of full-length isoforms encoded by individual genes. Applying this approach to neural cell-surface molecules, we identify thousands of unannotated isoforms expressed in retina and brain. By mass spectrometry we confirm expression of newly-discovered proteins on the cell surface in vivo. Remarkably, we discover that the major isoform of a retinal degeneration gene, CRB1, was previously overlooked. This CRB1 isoform is the only one expressed by photoreceptors, the affected cells in CRB1 disease. Using mouse mutants, we identify a function for this isoform at photoreceptor-glial junctions and demonstrate that loss of this isoform accelerates photoreceptor death. Therefore, our isoform identification strategy enables discovery of new gene functions relevant to disease.
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Affiliation(s)
- Thomas A Ray
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kelly Cochran
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Chris Kozlowski
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Jingjing Wang
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Graham Alexander
- Center for Genomic and Computational Biology, Duke University, Durham, NC, 27710, USA
| | | | | | - Philip A Ruzycki
- John F. Hardesty, M.D. Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, 63110, USA
| | - Brian S Clark
- John F. Hardesty, M.D. Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, 63110, USA
- Department of Developmental Biology, Washington University, St. Louis, MO, 63110, USA
| | | | - Ming-Xiao He
- Advanced Cell Diagnostics, Newark, CA, 94560, USA
| | | | - Emily Park
- Advanced Cell Diagnostics, Newark, CA, 94560, USA
| | - Ying Hao
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Alessandro Iannaccone
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Gary Hu
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Olivier Fedrigo
- Center for Genomic and Computational Biology, Duke University, Durham, NC, 27710, USA
- The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Nikolai P Skiba
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Jeremy N Kay
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA.
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20
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Han KA, Lee HY, Lim D, Shin J, Yoon TH, Liu X, Um JW, Choi SY, Ko J. Receptor protein tyrosine phosphatase delta is not essential for synapse maintenance or transmission at hippocampal synapses. Mol Brain 2020; 13:94. [PMID: 32552840 PMCID: PMC7301452 DOI: 10.1186/s13041-020-00629-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/29/2020] [Indexed: 12/26/2022] Open
Abstract
Members of the leukocyte common antigen-related receptor protein tyrosine phosphatase (LAR-RPTP) family, comprising PTPσ, PTPδ and LAR, are key hubs for presynaptic assembly and differentiation in vertebrate neurons. However, roles of individual LAR-RPTP members have not been investigated using member-specific conditional knockout mice. Here, we show that loss of PTPδ had no overt effect on synapse development in mouse cultured hippocampal neurons. Moreover, loss of PTPδ in presynaptic CA1 hippocampal neurons did not influence neurotransmitter release in subicular pyramidal neurons, suggesting that PTPδ is not critical for presynaptic function in vivo. Our results demonstrate that PTPδ is not essential for synapse maintenance or transmission, at least in the mouse hippocampus, and underscore the importance of using sophisticated genetic approaches to confirm the roles of synaptic proteins.
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Affiliation(s)
- Kyung Ah Han
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea.,Core Protein Resources Center, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea
| | - Hee-Yoon Lee
- Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080, South Korea
| | - Dongseok Lim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea
| | - Jungsu Shin
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea
| | - Taek Han Yoon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea
| | - Xinran Liu
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea.,Core Protein Resources Center, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea
| | - Se-Young Choi
- Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080, South Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988, South Korea.
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21
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Microexons: at the nexus of nervous system development, behaviour and autism spectrum disorder. Curr Opin Genet Dev 2020; 65:22-33. [PMID: 32535349 DOI: 10.1016/j.gde.2020.03.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 03/30/2020] [Indexed: 12/19/2022]
Abstract
The discovery and characterization of a network of highly conserved neuronal microexons has provided fundamental new insight into mechanisms underlying nervous system development and function, as well as an important basis for pathway convergence in autism spectrum disorder. In the past few years, considerable progress has been made in comprehensively determining the repertoires of factors that control neuronal microexons. These results have illuminated molecular mechanisms that activate the splicing of microexons, including those that control gene expression programs critical for neurogenesis, as well as synaptic protein translation and neuronal activity. Remarkably, individual disruption of specific microexons in these pathways results in autism-like phenotypes and cognitive impairment in mice. This review discusses these findings and their implications for delivering new therapeutic strategies for neurological disorders.
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22
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Han KA, Lee HY, Lim D, Shin J, Yoon TH, Lee C, Rhee JS, Liu X, Um JW, Choi SY, Ko J. PTPσ Controls Presynaptic Organization of Neurotransmitter Release Machinery at Excitatory Synapses. iScience 2020; 23:101203. [PMID: 32516721 PMCID: PMC7284068 DOI: 10.1016/j.isci.2020.101203] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/04/2020] [Accepted: 05/22/2020] [Indexed: 12/16/2022] Open
Abstract
Leukocyte common antigen-related receptor tyrosine phosphatases (LAR-RPTPs) are evolutionarily conserved presynaptic organizers. The synaptic role of vertebrate LAR-RPTPs in vivo, however, remains unclear. In the current study, we analyzed the synaptic role of PTPσ using newly generated, single conditional knockout (cKO) mice targeting PTPσ. We found that the number of synapses was reduced in PTPσ cKO cultured neurons in association with impaired excitatory synaptic transmission, abnormal vesicle localization, and abnormal synaptic ultrastructure. Strikingly, loss of presynaptic PTPσ reduced neurotransmitter release prominently at excitatory synapses, concomitant with drastic reductions in excitatory innervations onto postsynaptic target areas in vivo. Furthermore, loss of presynaptic PTPσ in hippocampal CA1 pyramidal neurons had no impact on postsynaptic glutamate receptor responses in subicular pyramidal neurons. Postsynaptic PTPσ deletion had no effect on excitatory synaptic strength. Taken together, these results demonstrate that PTPσ is a bona fide presynaptic adhesion molecule that controls neurotransmitter release and excitatory inputs. Conditional PTPσ KO produces specifically impaired presynaptic functions Presynaptic PTPσ regulates glutamate release efficiency Presynaptic PTPσ does not transsynaptically regulate postsynaptic receptor responses
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Affiliation(s)
- Kyung Ah Han
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea; Core Protein Resources Center, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea
| | - Hee-Yoon Lee
- Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul 03080, Korea
| | - Dongseok Lim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea
| | - Jungsu Shin
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea
| | - Taek Han Yoon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea
| | - Chooungku Lee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen 37075, Germany
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen 37075, Germany
| | - Xinran Liu
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea; Core Protein Resources Center, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea
| | - Se-Young Choi
- Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul 03080, Korea.
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, Korea.
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23
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Park H, Choi Y, Jung H, Kim S, Lee S, Han H, Kweon H, Kang S, Sim WS, Koopmans F, Yang E, Kim H, Smit AB, Bae YC, Kim E. Splice-dependent trans-synaptic PTPδ-IL1RAPL1 interaction regulates synapse formation and non-REM sleep. EMBO J 2020; 39:e104150. [PMID: 32347567 PMCID: PMC7265247 DOI: 10.15252/embj.2019104150] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 12/12/2022] Open
Abstract
Alternative splicing regulates trans‐synaptic adhesions and synapse development, but supporting in vivo evidence is limited. PTPδ, a receptor tyrosine phosphatase adhering to multiple synaptic adhesion molecules, is associated with various neuropsychiatric disorders; however, its in vivo functions remain unclear. Here, we show that PTPδ is mainly present at excitatory presynaptic sites by endogenous PTPδ tagging. Global PTPδ deletion in mice leads to input‐specific decreases in excitatory synapse development and strength. This involves tyrosine dephosphorylation and synaptic loss of IL1RAPL1, a postsynaptic partner of PTPδ requiring the PTPδ‐meA splice insert for binding. Importantly, PTPδ‐mutant mice lacking the PTPδ‐meA insert, and thus lacking the PTPδ interaction with IL1RAPL1 but not other postsynaptic partners, recapitulate biochemical and synaptic phenotypes of global PTPδ‐mutant mice. Behaviorally, both global and meA‐specific PTPδ‐mutant mice display abnormal sleep behavior and non‐REM rhythms. Therefore, alternative splicing in PTPδ regulates excitatory synapse development and sleep by modulating a specific trans‐synaptic adhesion.
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Affiliation(s)
- Haram Park
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Yeonsoo Choi
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hwajin Jung
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Seoyeong Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hyemin Han
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Hanseul Kweon
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Suwon Kang
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Woong Seob Sim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Frank Koopmans
- Department of Functional Genomics, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands.,Department of Molecular and Cellular Neurobiology, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands
| | - Esther Yang
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, CNCR, VU University and UMC Amsterdam, Amsterdam, The Netherlands
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea.,Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
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24
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Rodemer W, Zhang G, Sinitsa I, Hu J, Jin LQ, Li S, Selzer ME. PTPσ Knockdown in Lampreys Impairs Reticulospinal Axon Regeneration and Neuronal Survival After Spinal Cord Injury. Front Cell Neurosci 2020; 14:61. [PMID: 32265663 PMCID: PMC7096546 DOI: 10.3389/fncel.2020.00061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/02/2020] [Indexed: 01/10/2023] Open
Abstract
Traumatic spinal cord injury (SCI) results in persistent functional deficits due to the lack of axon regeneration within the mammalian CNS. After SCI, chondroitin sulfate proteoglycans (CSPGs) inhibit axon regrowth via putative interactions with the LAR-family protein tyrosine phosphatases, PTPσ and LAR, localized on the injured axon tips. Unlike mammals, the sea lamprey, Petromyzon marinus, robustly recovers locomotion after complete spinal cord transection (TX). Behavioral recovery is accompanied by heterogeneous yet predictable anatomical regeneration of the lamprey's reticulospinal (RS) system. The identified RS neurons can be categorized as "good" or "bad" regenerators based on the likelihood that their axons will regenerate. Those neurons that fail to regenerate their axons undergo a delayed form of caspase-mediated cell death. Previously, this lab reported that lamprey PTPσ mRNA is selectively expressed in "bad regenerator" RS neurons, preceding SCI-induced caspase activation. Consequently, we hypothesized that PTPσ deletion would reduce retrograde cell death and promote axon regeneration. Using antisense morpholino oligomers (MOs), we knocked down PTPσ expression after TX and assessed the effects on axon regeneration, caspase activation, intracellular signaling, and behavioral recovery. Unexpectedly, PTPσ knockdown significantly impaired RS axon regeneration at 10 weeks post-TX, primarily due to reduced long-term neuron survival. Interestingly, cell loss was not preceded by an increase in caspase or p53 activation. Behavioral recovery was largely unaffected, although PTPσ knockdowns showed mild deficits in the recovery of swimming distance and latency to immobility during open field swim assays. Although the mechanism underlying the cell death following TX and PTPσ knockdown remains unknown, this study suggests that PTPσ is not a net negative regulator of long tract axon regeneration in lampreys.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Guixin Zhang
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Isabelle Sinitsa
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- College of Science and Technology, Temple University, Philadelphia, PA, United States
| | - Jianli Hu
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Li-qing Jin
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Michael E. Selzer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
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25
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Kim K, Shin W, Kang M, Lee S, Kim D, Kang R, Jung Y, Cho Y, Yang E, Kim H, Bae YC, Kim E. Presynaptic PTPσ regulates postsynaptic NMDA receptor function through direct adhesion-independent mechanisms. eLife 2020; 9:54224. [PMID: 32142410 PMCID: PMC7069723 DOI: 10.7554/elife.54224] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Synaptic adhesion molecules regulate synapse development and function. However, whether and how presynaptic adhesion molecules regulate postsynaptic NMDAR function remains largely unclear. Presynaptic LAR family receptor tyrosine phosphatases (LAR-RPTPs) regulate synapse development through mechanisms that include trans-synaptic adhesion; however, whether they regulate postsynaptic receptor functions remains unknown. Here we report that presynaptic PTPσ, a LAR-RPTP, enhances postsynaptic NMDA receptor (NMDAR) currents and NMDAR-dependent synaptic plasticity in the hippocampus. This regulation does not involve trans-synaptic adhesions of PTPσ, suggesting that the cytoplasmic domains of PTPσ, known to have tyrosine phosphatase activity and mediate protein-protein interactions, are important. In line with this, phosphotyrosine levels of presynaptic proteins, including neurexin-1, are strongly increased in PTPσ-mutant mice. Behaviorally, PTPσ-dependent NMDAR regulation is important for social and reward-related novelty recognition. These results suggest that presynaptic PTPσ regulates postsynaptic NMDAR function through trans-synaptic and direct adhesion-independent mechanisms and novelty recognition in social and reward contexts.
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Affiliation(s)
- Kyungdeok Kim
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea
| | - Wangyong Shin
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Muwon Kang
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Ryeonghwa Kang
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea
| | - Yewon Jung
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea
| | - Yisul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Esther Yang
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Eunjoon Kim
- Department of Biological Sciences, KAIST, Daejeon, Republic of Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Republic of Korea
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26
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Structural insights into selective interaction between type IIa receptor protein tyrosine phosphatases and Liprin-α. Nat Commun 2020; 11:649. [PMID: 32005855 PMCID: PMC6994669 DOI: 10.1038/s41467-020-14516-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 01/15/2020] [Indexed: 01/07/2023] Open
Abstract
Synapse formation is induced by transsynaptic interaction of neuronal cell-adhesion molecules termed synaptic organizers. Type IIa receptor protein tyrosine phosphatases (IIa RPTPs) function as presynaptic organizers. The cytoplasmic domain of IIa RPTPs consists of two phosphatase domains, and the membrane-distal one (D2) is essential for synapse formation. Liprin-α, which is an active zone protein critical for synapse formation, interacts with D2 via its C-terminal domain composed of three tandem sterile alpha motifs (tSAM). Structural mechanisms of this critical interaction for synapse formation remain elusive. Here, we report the crystal structure of the complex between mouse PTPδ D2 and Liprin-α3 tSAM at 1.91 Å resolution. PTPδ D2 interacts with the N-terminal helix and the first and second SAMs (SAM1 and SAM2, respectively) of Liprin-α3. Structure-based mutational analyses in vitro and in cellulo demonstrate that the interactions with Liprin-α SAM1 and SAM2 are essential for the binding and synaptogenic activity.
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27
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Sclip A, Südhof TC. LAR receptor phospho-tyrosine phosphatases regulate NMDA-receptor responses. eLife 2020; 9:53406. [PMID: 31985401 PMCID: PMC6984820 DOI: 10.7554/elife.53406] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 01/08/2020] [Indexed: 12/24/2022] Open
Abstract
LAR-type receptor phosphotyrosine-phosphatases (LAR-RPTPs) are presynaptic adhesion molecules that interact trans-synaptically with multitudinous postsynaptic adhesion molecules, including SliTrks, SALMs, and TrkC. Via these interactions, LAR-RPTPs are thought to function as synaptogenic wiring molecules that promote neural circuit formation by mediating the establishment of synapses. To test the synaptogenic functions of LAR-RPTPs, we conditionally deleted the genes encoding all three LAR-RPTPs, singly or in combination, in mice before synapse formation. Strikingly, deletion of LAR-RPTPs had no effect on synaptic connectivity in cultured neurons or in vivo, but impaired NMDA-receptor-mediated responses. Deletion of LAR-RPTPs decreased NMDA-receptor-mediated responses by a trans-synaptic mechanism. In cultured neurons, deletion of all LAR-RPTPs led to a reduction in synaptic NMDA-receptor EPSCs, without changing the subunit composition or the protein levels of NMDA-receptors. In vivo, deletion of all LAR-RPTPs in the hippocampus at birth also did not alter synaptic connectivity as measured via AMPA-receptor-mediated synaptic responses at Schaffer-collateral synapses monitored in juvenile mice, but again decreased NMDA-receptor mediated synaptic transmission. Thus, LAR-RPTPs are not essential for synapse formation, but control synapse properties by regulating postsynaptic NMDA-receptors via a trans-synaptic mechanism that likely involves binding to one or multiple postsynaptic ligands.
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Affiliation(s)
- Alessandra Sclip
- Department of Cellular and Molecular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, United States
| | - Thomas C Südhof
- Department of Cellular and Molecular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, United States
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28
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Brouwer M, Farzana F, Koopmans F, Chen N, Brunner JW, Oldani S, Li KW, van Weering JR, Smit AB, Toonen RF, Verhage M. SALM1 controls synapse development by promoting F-actin/PIP2-dependent Neurexin clustering. EMBO J 2019; 38:e101289. [PMID: 31368584 PMCID: PMC6717895 DOI: 10.15252/embj.2018101289] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 06/20/2019] [Accepted: 06/25/2019] [Indexed: 11/17/2022] Open
Abstract
Synapse development requires spatiotemporally regulated recruitment of synaptic proteins. In this study, we describe a novel presynaptic mechanism of cis‐regulated oligomerization of adhesion molecules that controls synaptogenesis. We identified synaptic adhesion‐like molecule 1 (SALM1) as a constituent of the proposed presynaptic Munc18/CASK/Mint1/Lin7b organizer complex. SALM1 preferentially localized to presynaptic compartments of excitatory hippocampal neurons. SALM1 depletion in excitatory hippocampal primary neurons impaired Neurexin1β‐ and Neuroligin1‐mediated excitatory synaptogenesis and reduced synaptic vesicle clustering, synaptic transmission, and synaptic vesicle release. SALM1 promoted Neurexin1β clustering in an F‐actin‐ and PIP2‐dependent manner. Two basic residues in SALM1's juxtamembrane polybasic domain are essential for this clustering. Together, these data show that SALM1 is a presynaptic organizer of synapse development by promoting F‐actin/PIP2‐dependent clustering of Neurexin.
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Affiliation(s)
- Marinka Brouwer
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Fatima Farzana
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Frank Koopmans
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands.,Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Ning Chen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands.,Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Jessie W Brunner
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Silvia Oldani
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Jan Rt van Weering
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, Amsterdam, The Netherlands
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29
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Lee H, Shin W, Kim K, Lee S, Lee EJ, Kim J, Kweon H, Lee E, Park H, Kang M, Yang E, Kim H, Kim E. NGL-3 in the regulation of brain development, Akt/GSK3b signaling, long-term depression, and locomotive and cognitive behaviors. PLoS Biol 2019; 17:e2005326. [PMID: 31166939 PMCID: PMC6550391 DOI: 10.1371/journal.pbio.2005326] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/13/2019] [Indexed: 01/04/2023] Open
Abstract
Netrin-G ligand-3 (NGL-3) is a postsynaptic adhesion molecule known to directly interact with the excitatory postsynaptic scaffolding protein postsynaptic density-95 (PSD-95) and trans-synaptically with leukocyte common antigen-related (LAR) family receptor tyrosine phosphatases to regulate presynaptic differentiation. Although NGL-3 has been implicated in the regulation of excitatory synapse development by in vitro studies, whether it regulates synapse development or function, or any other features of brain development and function, is not known. Here, we report that mice lacking NGL-3 (Ngl3−/− mice) show markedly suppressed normal brain development and postnatal survival and growth. A change of the genetic background of mice from pure to hybrid minimized these developmental effects but modestly suppressed N-methyl-D-aspartate (NMDA) receptor (NMDAR)-mediated synaptic transmission in the hippocampus without affecting synapse development, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor (AMPAR)-mediated basal transmission, and presynaptic release. Intriguingly, long-term depression (LTD) was near-completely abolished in Ngl3−/− mice, and the Akt/glycogen synthase kinase 3β (GSK3β) signaling pathway, known to suppress LTD, was abnormally enhanced. In addition, pharmacological inhibition of Akt, but not activation of NMDARs, normalized the suppressed LTD in Ngl3−/− mice, suggesting that Akt hyperactivity suppresses LTD. Ngl3−/− mice displayed several behavioral abnormalities, including hyperactivity, anxiolytic-like behavior, impaired spatial memory, and enhanced seizure susceptibility. Among them, the hyperactivity was rapidly improved by pharmacological NMDAR activation. These results suggest that NGL-3 regulates brain development, Akt/GSK3β signaling, LTD, and locomotive and cognitive behaviors.
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Affiliation(s)
- Hyejin Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Wangyong Shin
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Kyungdeok Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Suho Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Eun-Jae Lee
- Department of Neurology, Asan Medical Center University of Ulsan, College of Medicine, Seoul, South Korea
| | - Jihye Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Hanseul Kweon
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Eunee Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Muwon Kang
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
| | - Esther Yang
- Department of Anatomy, College of Medicine, Korea University, Seoul, Korea
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University, Seoul, Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Korea
- * E-mail:
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30
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Bomkamp C, Padmanabhan N, Karimi B, Ge Y, Chao JT, Loewen CJR, Siddiqui TJ, Craig AM. Mechanisms of PTPσ-Mediated Presynaptic Differentiation. Front Synaptic Neurosci 2019; 11:17. [PMID: 31191292 PMCID: PMC6540616 DOI: 10.3389/fnsyn.2019.00017] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/06/2019] [Indexed: 11/13/2022] Open
Abstract
Formation of synapses between neurons depends in part on binding between axonal and dendritic cell surface synaptic organizing proteins, which recruit components of the developing presynaptic and postsynaptic specializations. One of these presynaptic organizing molecules is protein tyrosine phosphatase σ (PTPσ). Although the protein domains involved in adhesion between PTPσ and its postsynaptic binding partners are known, the mechanisms by which it signals into the presynaptic neuron to recruit synaptic vesicles and other necessary components for regulated transmitter release are not well understood. One attractive candidate to mediate this function is liprin-α, a scaffolding protein with well-established roles at the synapse. We systematically mutated residues of the PTPσ intracellular region (ICR) and used the yeast dihydrofolate reductase (DHFR) protein complementation assay to screen for disrupted interactions between these mutant forms of PTPσ and its various binding partners. Using a molecular replacement strategy, we show that disrupting the interaction between PTPσ and liprin-α, but not between PTPσ and itself or another binding partner, caskin, abolishes presynaptic differentiation. Furthermore, phosphatase activity of PTPσ and binding to extracellular heparan sulfate (HS) proteoglycans are dispensable for presynaptic induction. Previous reports have suggested that binding between PTPσ and liprin-α is mediated by the PTPσ membrane-distal phosphatase-like domain. However, we provide evidence here that both of the PTPσ phosphatase-like domains mediate binding to liprin-α and are required for PTPσ-mediated presynaptic differentiation. These findings further our understanding of the mechanistic basis by which PTPσ acts as a presynaptic organizer.
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Affiliation(s)
- Claire Bomkamp
- Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Nirmala Padmanabhan
- Health Sciences Centre, Kleysen Institute for Advanced Medicine, University of Manitoba, Winnipeg, MB, Canada.,Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,The Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, MB, Canada
| | - Benyamin Karimi
- Health Sciences Centre, Kleysen Institute for Advanced Medicine, University of Manitoba, Winnipeg, MB, Canada.,Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,The Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, MB, Canada
| | - Yuan Ge
- Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Jesse T Chao
- Department of Cellular and Physiological Sciences, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Christopher J R Loewen
- Department of Cellular and Physiological Sciences, Faculty of Medicine, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Tabrez J Siddiqui
- Health Sciences Centre, Kleysen Institute for Advanced Medicine, University of Manitoba, Winnipeg, MB, Canada.,Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,The Children's Hospital Research Institute of Manitoba (CHRIM), Winnipeg, MB, Canada
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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31
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Chen P, Ijomone OM, Lee KH, Aschner M. Caenorhabditis elegans and its applicability to studies on restless legs syndrome. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2019; 84:147-174. [PMID: 31229169 DOI: 10.1016/bs.apha.2018.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Restless legs syndrome (RLS) is a common neurological disorder in the United States. This disorder is characterized by an irresistible urge to move the legs, although the symptoms vary in a wide range. The pathobiology of RLS has been linked to iron (Fe) deficiency and dopaminergic (DAergic) dysfunction. Several genetic factors have been reported to increase the risk of RLS. Caenorhabditis elegans (C. elegans) is a well-established animal model with a fully sequenced genome, which is highly conserved with mammals. Given the detailed knowledge of its genomic architecture, ease of genetic manipulation and conserved biosynthetic and metabolic pathways, as well as its small size, ease of maintenance, speedy generation time and large brood size, C. elegans provides numerous advantages in studying RLS-associated gene-environment interactions. Here we will review current knowledge about RLS symptoms, pathology and treatments, and discuss the application of C. elegans in RLS study, including the worm homologous genes and methods that could be performed to advance the pathophysiology RLS.
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Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Omamuyovwi Meashack Ijomone
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States; Department of Human Anatomy, Federal University of Technology, Akure, Nigeria
| | - Kun He Lee
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
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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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33
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Liu H. Synaptic organizers: synaptic adhesion-like molecules (SALMs). Curr Opin Struct Biol 2019; 54:59-67. [PMID: 30743183 DOI: 10.1016/j.sbi.2019.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/24/2018] [Accepted: 01/06/2019] [Indexed: 12/18/2022]
Abstract
Synaptic adhesion-like molecules (SALMs), also known as leucine-rich repeat and fibronectin III domain-containing proteins (LRFNs), are a family of synaptic adhesion molecules that consist of five members. SALMs exhibit functions in regulating neurite outgrowth and branching, synapse formation, and synapse maturation. Recent clinical studies have shown an association of SALMs with diverse neurological disorders. In this review article, we summarize structural mechanisms of the interaction of SALMs with leukocyte common antigen (LAR) family receptor tyrosine phosphatases (LAR-RPTPs) for synaptic activity, based on recent advances in the structural biology of SALMs.
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Affiliation(s)
- Heli Liu
- State Key Laboratory of Natural and Biomimetic Drugs, 38 Xueyuan Road, Haidian District, Beijing 100191, China; Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, 38 Xueyuan Road, Haidian District, Beijing 100191, China.
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34
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Won SY, Lee P, Kim HM. Synaptic organizer: Slitrks and type IIa receptor protein tyrosine phosphatases. Curr Opin Struct Biol 2019; 54:95-103. [PMID: 30822649 DOI: 10.1016/j.sbi.2019.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 10/27/2022]
Abstract
Slit-like and Trk-like (Slitrk) family members are leucine-rich repeat (LRR)-containing neuronal transmembrane proteins. Slitrks have been highlighted as key synapse organizers at neuronal synapses through interactions with specific members of the presynaptic type IIa receptor protein tyrosine phosphatase (RPTP) family. Recent structural studies on type IIa RPTP/Slitrk1 complexes have unveiled molecular insights into their binding selectivity and have established the role of higher-order receptor clustering in their synaptogenic activity. Here, we will discuss key structural aspects of Slitrk interactions with type IIa RPTP family members, the biological roles of Slitrks in neurons, and our current knowledge of SLITRK mutations in human diseases.
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Affiliation(s)
- Seoung Youn Won
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Pedro Lee
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Ho Min Kim
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; Center for Biomolecular & Cellular Structure, Institute for Basic Science (IBS), Daejeon, Republic of Korea.
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35
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Karki S, Paudel P, Sele C, Shkumatov AV, Kajander T. The structure of SALM5 suggests a dimeric assembly for the presynaptic RPTP ligand recognition. Protein Eng Des Sel 2019; 31:147-157. [PMID: 29897575 DOI: 10.1093/protein/gzy012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/15/2018] [Indexed: 12/28/2022] Open
Abstract
Synaptic adhesion molecules play a crucial role in the regulation of synapse development and maintenance. Recently, several families of leucine-rich repeat (LRR) domain-containing neuronal adhesion molecules have been characterised, including netrin-G ligands, LRRTMs and the synaptic adhesion-like molecule (SALM) family proteins. Most of these are expressed at the excitatory glutamatergic synapses, and dysfunctions of these genes are genetically linked with cognitive disorders, such as autism spectrum disorders and schizophrenia. The SALM family proteins SALM3 and SALM5, similar to SLITRKs, have been shown to bind to the presynaptic receptor protein tyrosine phosphatase (RPTP) family ligands. Here, we present the 3.1 Å crystal structure of the SALM5 LRR-Ig-domain construct and biophysical studies that verify the crystallographic results. We show that SALM1, SALM3 and SALM5 form similar dimeric structures, in which the LRR domains form the dimer interface. Both SALM3 and SALM5 bind to RPTP immunoglobulin domains with micromolar affinity. SALM3 shows a clear preference for the RPTP ligands with the meB splice insert. Our structural studies and sequence conservation analysis suggests a ligand-binding site and mechanism for RPTP binding via the dimeric LRR domain region.
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Affiliation(s)
- Sudeep Karki
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Prodeep Paudel
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Celeste Sele
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Alexander V Shkumatov
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels 1050, Belgium.,VIB-VUB Center for Structural Biology, Brussels 1050, Belgium
| | - Tommi Kajander
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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Anesthesia affects excitatory/inhibitory synapses during the critical synaptogenic period in the hippocampus of young mice: Importance of sex as a biological variable. Neurotoxicology 2019; 70:146-153. [DOI: 10.1016/j.neuro.2018.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/17/2018] [Accepted: 11/27/2018] [Indexed: 11/18/2022]
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Abstract
Synapse formation is mediated by a surprisingly large number and wide variety of genes encoding many different protein classes. One of the families increasingly implicated in synapse wiring is the immunoglobulin superfamily (IgSF). IgSF molecules are by definition any protein containing at least one Ig-like domain, making this family one of the most common protein classes encoded by the genome. Here, we review the emerging roles for IgSF molecules in synapse formation specifically in the vertebrate brain, focusing on examples from three classes of IgSF members: ( a) cell adhesion molecules, ( b) signaling molecules, and ( c) immune molecules expressed in the brain. The critical roles for IgSF members in regulating synapse formation may explain their extensive involvement in neuropsychiatric and neurodevelopmental disorders. Solving the IgSF code for synapse formation may reveal multiple new targets for rescuing IgSF-mediated deficits in synapse formation and, eventually, new treatments for psychiatric disorders caused by altered IgSF-induced synapse wiring.
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Affiliation(s)
- Scott Cameron
- Center for Neuroscience, University of California, Davis, California 95618, USA; ,
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38
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Won SY, Kim HM. Structural Basis for LAR-RPTP-Mediated Synaptogenesis. Mol Cells 2018; 41:622-630. [PMID: 30008201 PMCID: PMC6078854 DOI: 10.14348/molcells.2018.0202] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/10/2018] [Accepted: 06/25/2018] [Indexed: 12/28/2022] Open
Abstract
Leukocyte common antigen-related protein tyrosine phosphatases (LAR-RPTPs) are cellular receptors of heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans that regulate neurite outgrowth and neuronal regeneration. LAR-RPTPs have also received particular attention as the major presynaptic hubs for synapse organization through selective binding to numerous postsynaptic adhesion partners. Recent structural studies on LAR-RPTP-mediated trans-synaptic adhesion complexes have provided significant insight into the molecular basis of their specific interactions, the key codes for their selective binding, as well as the higher-order clustering of LAR-RPTPs necessary for synaptogenic activity. In this review, we summarize the structures of LAR-RPTPs in complex with various postsynaptic adhesion partners and discuss the molecular mechanisms underlying LAR-RPTP-mediated synaptogenesis.
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Affiliation(s)
- Seoung Youn Won
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Ho Min Kim
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141,
Korea
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39
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Furlanis E, Scheiffele P. Regulation of Neuronal Differentiation, Function, and Plasticity by Alternative Splicing. Annu Rev Cell Dev Biol 2018; 34:451-469. [PMID: 30028642 DOI: 10.1146/annurev-cellbio-100617-062826] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Posttranscriptional mechanisms provide powerful means to expand the coding power of genomes. In nervous systems, alternative splicing has emerged as a fundamental mechanism not only for the diversification of protein isoforms but also for the spatiotemporal control of transcripts. Thus, alternative splicing programs play instructive roles in the development of neuronal cell type-specific properties, neuronal growth, self-recognition, synapse specification, and neuronal network function. Here we discuss the most recent genome-wide efforts on mapping RNA codes and RNA-binding proteins for neuronal alternative splicing regulation. We illustrate how alternative splicing shapes key steps of neuronal development, neuronal maturation, and synaptic properties. Finally, we highlight efforts to dissect the spatiotemporal dynamics of alternative splicing and their potential contribution to neuronal plasticity and the mature nervous system.
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40
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PTPσ Drives Excitatory Presynaptic Assembly via Various Extracellular and Intracellular Mechanisms. J Neurosci 2018; 38:6700-6721. [PMID: 29934346 DOI: 10.1523/jneurosci.0672-18.2018] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/22/2018] [Accepted: 06/14/2018] [Indexed: 11/21/2022] Open
Abstract
Leukocyte common antigen-receptor protein tyrosine phosphatases (LAR-RPTPs) are hub proteins that organize excitatory and inhibitory synapse development through binding to various extracellular ligands. Here, we report that knockdown (KD) of the LAR-RPTP family member PTPσ reduced excitatory synapse number and transmission in cultured rat hippocampal neurons, whereas KD of PTPδ produced comparable decreases at inhibitory synapses, in both cases without altering expression levels of interacting proteins. An extensive series of rescue experiments revealed that extracellular interactions of PTPσ with Slitrks are important for excitatory synapse development. These experiments further showed that the intracellular D2 domain of PTPσ is required for induction of heterologous synapse formation by Slitrk1 or TrkC, suggesting that interaction of LAR-RPTPs with distinct intracellular presynaptic proteins, drives presynaptic machinery assembly. Consistent with this, double-KD of liprin-α2 and -α3 or KD of PTPσ substrates (N-cadherin and p250RhoGAP) in neurons inhibited Slitrk6-induced, PTPσ-mediated heterologous synapse formation activity. We propose a synaptogenesis model in presynaptic neurons involving LAR-RPTP-organized retrograde signaling cascades, in which both extracellular and intracellular mechanisms are critical in orchestrating distinct synapse types.SIGNIFICANCE STATEMENT In this study, we sought to test the unproven hypothesis that PTPσ and PTPδ are required for excitatory and inhibitory synapse formation/transmission, respectively, in cultured hippocampal neurons, using knockdown-based loss-of-function analyses. We further performed extensive structure-function analyses, focusing on PTPσ-mediated actions, to address the mechanisms of presynaptic assembly at excitatory synaptic sites. Using interdisciplinary approaches, we systematically applied a varied set of PTPσ deletion variants, point mutants, and splice variants to demonstrate that both extracellular and intracellular mechanisms are involved in organizing presynaptic assembly. Strikingly, extracellular interactions of PTPσ with heparan sulfates and Slitrks, intracellular interactions of PTPσ with liprin-α and its associated proteins through the D2 domain, as well as distinct substrates are all critical.
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Lrfn2-Mutant Mice Display Suppressed Synaptic Plasticity and Inhibitory Synapse Development and Abnormal Social Communication and Startle Response. J Neurosci 2018; 38:5872-5887. [PMID: 29798891 DOI: 10.1523/jneurosci.3321-17.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 05/03/2018] [Accepted: 05/16/2018] [Indexed: 11/21/2022] Open
Abstract
SALM1 (SALM (synaptic adhesion-like molecule), also known as LRFN2 (leucine rich repeat and fibronectin type III domain containing), is a postsynaptic density (PSD)-95-interacting synaptic adhesion molecule implicated in the regulation of NMDA receptor (NMDAR) clustering largely based on in vitro data, although its in vivo functions remain unclear. Here, we found that mice lacking SALM1/LRFN2 (Lrfn2-/- mice) show a normal density of excitatory synapses but altered excitatory synaptic function, including enhanced NMDAR-dependent synaptic transmission but suppressed NMDAR-dependent synaptic plasticity in the hippocampal CA1 region. Unexpectedly, SALM1 expression was detected in both glutamatergic and GABAergic neurons and Lrfn2-/- CA1 pyramidal neurons showed decreases in the density of inhibitory synapses and the frequency of spontaneous inhibitory synaptic transmission. Behaviorally, ultrasonic vocalization was suppressed in Lrfn2-/- pups separated from their mothers and acoustic startle was enhanced, but locomotion, anxiety-like behavior, social interaction, repetitive behaviors, and learning and memory were largely normal in adult male Lrfn2-/- mice. These results suggest that SALM1/LRFN2 regulates excitatory synapse function, inhibitory synapse development, and social communication and startle behaviors in mice.SIGNIFICANCE STATEMENT Synaptic adhesion molecules regulate synapse development and function, which govern neural circuit and brain functions. The SALM/LRFN (synaptic adhesion-like molecule/leucine rich repeat and fibronectin type III domain containing) family of synaptic adhesion proteins consists of five known members for which the in vivo functions are largely unknown. Here, we characterized mice lacking SALM1/LRFN2 (SALM1 KO) known to associate with NMDA receptors (NMDARs) and found that these mice showed altered NMDAR-dependent synaptic transmission and plasticity, as expected, but unexpectedly also exhibited suppressed inhibitory synapse development and synaptic transmission. Behaviorally, SALM1 KO pups showed suppressed ultrasonic vocalization upon separation from their mothers and SALM1 KO adults showed enhanced responses to loud acoustic stimuli. These results suggest that SALM1/LRFN2 regulates excitatory synapse function, inhibitory synapse development, social communication, and acoustic startle behavior.
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42
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Varshney A, Benedetti K, Watters K, Shankar R, Tatarakis D, Coto Villa D, Magallanes K, Agenor V, Wung W, Farah F, Ali N, Le N, Pyle J, Farooqi A, Kieu Z, Bremer M, VanHoven M. The receptor protein tyrosine phosphatase CLR-1 is required for synaptic partner recognition. PLoS Genet 2018; 14:e1007312. [PMID: 29742100 PMCID: PMC5942785 DOI: 10.1371/journal.pgen.1007312] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 03/19/2018] [Indexed: 11/19/2022] Open
Abstract
During neural circuit formation, most axons are guided to complex environments, coming into contact with multiple potential synaptic partners. However, it is critical that they recognize specific neurons with which to form synapses. Here, we utilize the split GFP-based marker Neuroligin-1 GFP Reconstitution Across Synaptic Partners (NLG-1 GRASP) to visualize specific synapses in live animals, and a circuit-specific behavioral assay to probe circuit function. We demonstrate that the receptor protein tyrosine phosphatase (RPTP) clr-1 is necessary for synaptic partner recognition (SPR) between the PHB sensory neurons and the AVA interneurons in C. elegans. Mutations in clr-1/RPTP result in reduced NLG-1 GRASP fluorescence and impaired behavioral output of the PHB circuit. Temperature-shift experiments demonstrate that clr-1/RPTP acts early in development, consistent with a role in SPR. Expression and cell-specific rescue experiments indicate that clr-1/RPTP functions in postsynaptic AVA neurons, and overexpression of clr-1/RPTP in AVA neurons is sufficient to direct additional PHB-AVA synaptogenesis. Genetic analysis reveals that clr-1/RPTP acts in the same pathway as the unc-6/Netrin ligand and the unc-40/DCC receptor, which act in AVA and PHB neurons, respectively. This study defines a new mechanism by which SPR is governed, and demonstrates that these three conserved families of molecules, with roles in neurological disorders and cancer, can act together to regulate communication between cells.
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Affiliation(s)
- Aruna Varshney
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Kelli Benedetti
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Katherine Watters
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Raakhee Shankar
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - David Tatarakis
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Doris Coto Villa
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Khristina Magallanes
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Venia Agenor
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - William Wung
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Fatima Farah
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Nebat Ali
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Nghi Le
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Jacqueline Pyle
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Amber Farooqi
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Zanett Kieu
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
| | - Martina Bremer
- Department of Mathematics and Statistics, San Jose State University, San Jose, CA, United States of America
| | - Miri VanHoven
- Department of Biological Sciences, San Jose State University, San Jose, CA, United States of America
- * E-mail:
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Leucine-rich repeat-containing synaptic adhesion molecules as organizers of synaptic specificity and diversity. Exp Mol Med 2018; 50:1-9. [PMID: 29628503 PMCID: PMC5938020 DOI: 10.1038/s12276-017-0023-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022] Open
Abstract
The brain harbors billions of neurons that form distinct neural circuits with exquisite specificity. Specific patterns of connectivity between distinct neuronal cell types permit the transfer and computation of information. The molecular correlates that give rise to synaptic specificity are incompletely understood. Recent studies indicate that cell-surface molecules are important determinants of cell type identity and suggest that these are essential players in the specification of synaptic connectivity. Leucine-rich repeat (LRR)-containing adhesion molecules in particular have emerged as key organizers of excitatory and inhibitory synapses. Here, we discuss emerging evidence that LRR proteins regulate the assembly of specific connectivity patterns across neural circuits, and contribute to the diverse structural and functional properties of synapses, two key features that are critical for the proper formation and function of neural circuits. Further analysis of synaptic proteins will provide insights into the functioning of neural circuits and associated brain disorders. The brain houses numerous highly specialized neuron types, which transfer and process information via a complex network of synaptic connections. Every neuron develops its own distinctive synapses with specific functions, but exactly how this is achieved is not clear. Joris de Wit and Anna Schroeder at the VIB Center for Brain and Disease Research in Leuven, Belgium, reviewed recent research into the leucine-rich repeat-containing (LRR) proteins, which are thought to be major organizers of synaptic connectivity and key regulators of healthy neural circuit development. Further investigations into the functionality of LRR proteins in the brain will not only improve understanding of neural circuitry but also provide insights into synaptic impairments in brain disorders like schizophrenia.
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44
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Lie E, Li Y, Kim R, Kim E. SALM/Lrfn Family Synaptic Adhesion Molecules. Front Mol Neurosci 2018; 11:105. [PMID: 29674953 PMCID: PMC5895706 DOI: 10.3389/fnmol.2018.00105] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/19/2018] [Indexed: 12/31/2022] Open
Abstract
Synaptic adhesion-like molecules (SALMs) are a family of cell adhesion molecules involved in regulating neuronal and synapse development that have also been implicated in diverse brain dysfunctions, including autism spectrum disorders (ASDs). SALMs, also known as leucine-rich repeat (LRR) and fibronectin III domain-containing (LRFN) proteins, were originally identified as a group of novel adhesion-like molecules that contain LRRs in the extracellular region as well as a PDZ domain-binding tail that couples to PSD-95, an abundant excitatory postsynaptic scaffolding protein. While studies over the last decade have steadily explored the basic properties and synaptic and neuronal functions of SALMs, a number of recent studies have provided novel insights into molecular, structural, functional and clinical aspects of SALMs. Here we summarize these findings and discuss how SALMs act in concert with other synaptic proteins to regulate synapse development and function.
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Affiliation(s)
- Eunkyung Lie
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Yan Li
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Ryunhee Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea.,Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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Structural basis of trans-synaptic interactions between PTPδ and SALMs for inducing synapse formation. Nat Commun 2018; 9:269. [PMID: 29348429 PMCID: PMC5773591 DOI: 10.1038/s41467-017-02417-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 11/29/2017] [Indexed: 01/23/2023] Open
Abstract
Synapse formation is triggered by trans-synaptic interactions of cell adhesion molecules, termed synaptic organizers. Three members of type-II receptor protein tyrosine phosphatases (classified as type-IIa RPTPs; PTPδ, PTPσ and LAR) are known as presynaptic organizers. Synaptic adhesion-like molecules (SALMs) have recently emerged as a family of postsynaptic organizers. Although all five SALM isoforms can bind to the type-IIa RPTPs, only SALM3 and SALM5 reportedly have synaptogenic activities depending on their binding. Here, we report the crystal structures of apo-SALM5, and PTPδ–SALM2 and PTPδ–SALM5 complexes. The leucine-rich repeat (LRR) domains of SALMs interact with the second immunoglobulin-like (Ig) domain of PTPδ, whereas the Ig domains of SALMs interact with both the second and third Ig domains of PTPδ. Unexpectedly, the structures exhibit the LRR-mediated 2:2 complex. Our synaptogenic co-culture assay using site-directed SALM5 mutants demonstrates that presynaptic differentiation induced by PTPδ–SALM5 requires the dimeric property of SALM5. Synaptic organizers are cell adhesion molecules that facilitate synapse formation through trans-synaptic interactions. Here the authors give molecular insights into synaptic differentiation by determining the structures of the synaptic adhesion-like molecules SALM2 and SALM5 bound to the presynaptic organizer PTPδ.
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46
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Structural basis of SALM5-induced PTPδ dimerization for synaptic differentiation. Nat Commun 2018; 9:268. [PMID: 29348579 PMCID: PMC5773555 DOI: 10.1038/s41467-017-02414-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/29/2017] [Indexed: 12/29/2022] Open
Abstract
SALM5, a synaptic adhesion molecule implicated in autism, induces presynaptic differentiation through binding to the LAR family receptor protein tyrosine phosphatases (LAR-RPTPs) that have been highlighted as presynaptic hubs for synapse formation. The mechanisms underlying SALM5/LAR-RPTP interaction remain unsolved. Here we report crystal structures of human SALM5 LRR-Ig alone and in complex with human PTPδ Ig1–3 (MeA−). Distinct from other LAR-RPTP ligands, SALM5 mainly exists as a dimer with LRR domains from two protomers packed in an antiparallel fashion. In the 2:2 heterotetrameric SALM5/PTPδ complex, a SALM5 dimer bridges two separate PTPδ molecules. Structure-guided mutations and heterologous synapse formation assays demonstrate that dimerization of SALM5 is prerequisite for its functionality in inducing synaptic differentiation. This study presents a structural template for the SALM family and reveals a mechanism for how a synaptic adhesion molecule directly induces cis-dimerization of LAR-RPTPs into higher-order signaling assembly. Synaptic adhesion molecules mediate synaptic differentiation and formation. Here the authors present the structures of the synaptic adhesion molecule SALM5 alone and in complex with the LAR family receptor protein tyrosine phosphatase (LAR-RPTP) PTPδ, which reveals how SALM5 dimerization facilitates higher-order signaling assembly of LAR-RPTPs.
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Abstract
At each of the brain's vast number of synapses, the presynaptic nerve terminal, synaptic cleft, and postsynaptic specialization form a transcellular unit to enable efficient transmission of information between neurons. While we know much about the molecular machinery within each compartment, we are only beginning to understand how these compartments are structurally registered and functionally integrated with one another. This review will describe the organization of each compartment and then discuss their alignment across pre- and postsynaptic cells at a nanometer scale. We propose that this architecture may allow for precise synaptic information exchange and may be modulated to contribute to the remarkable plasticity of brain function.
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Affiliation(s)
- Thomas Biederer
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Schormair B, Zhao C, Bell S, Tilch E, Salminen AV, Pütz B, Dauvilliers Y, Stefani A, Högl B, Poewe W, Kemlink D, Sonka K, Bachmann CG, Paulus W, Trenkwalder C, Oertel WH, Hornyak M, Teder-Laving M, Metspalu A, Hadjigeorgiou GM, Polo O, Fietze I, Ross OA, Wszolek Z, Butterworth AS, Soranzo N, Ouwehand WH, Roberts DJ, Danesh J, Allen RP, Earley CJ, Ondo WG, Xiong L, Montplaisir J, Gan-Or Z, Perola M, Vodicka P, Dina C, Franke A, Tittmann L, Stewart AFR, Shah SH, Gieger C, Peters A, Rouleau GA, Berger K, Oexle K, Di Angelantonio E, Hinds DA, Müller-Myhsok B, Winkelmann J. Identification of novel risk loci for restless legs syndrome in genome-wide association studies in individuals of European ancestry: a meta-analysis. Lancet Neurol 2017; 16:898-907. [PMID: 29029846 PMCID: PMC5755468 DOI: 10.1016/s1474-4422(17)30327-7] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 02/02/2023]
Abstract
BACKGROUND Restless legs syndrome is a prevalent chronic neurological disorder with potentially severe mental and physical health consequences. Clearer understanding of the underlying pathophysiology is needed to improve treatment options. We did a meta-analysis of genome-wide association studies (GWASs) to identify potential molecular targets. METHODS In the discovery stage, we combined three GWAS datasets (EU-RLS GENE, INTERVAL, and 23andMe) with diagnosis data collected from 2003 to 2017, in face-to-face interviews or via questionnaires, and involving 15 126 cases and 95 725 controls of European ancestry. We identified common variants by fixed-effect inverse-variance meta-analysis. Significant genome-wide signals (p≤5 × 10-8) were tested for replication in an independent GWAS of 30 770 cases and 286 913 controls, followed by a joint analysis of the discovery and replication stages. We did gene annotation, pathway, and gene-set-enrichment analyses and studied the genetic correlations between restless legs syndrome and traits of interest. FINDINGS We identified and replicated 13 new risk loci for restless legs syndrome and confirmed the previously identified six risk loci. MEIS1 was confirmed as the strongest genetic risk factor for restless legs syndrome (odds ratio 1·92, 95% CI 1·85-1·99). Gene prioritisation, enrichment, and genetic correlation analyses showed that identified pathways were related to neurodevelopment and highlighted genes linked to axon guidance (associated with SEMA6D), synapse formation (NTNG1), and neuronal specification (HOXB cluster family and MYT1). INTERPRETATION Identification of new candidate genes and associated pathways will inform future functional research. Advances in understanding of the molecular mechanisms that underlie restless legs syndrome could lead to new treatment options. We focused on common variants; thus, additional studies are needed to dissect the roles of rare and structural variations. FUNDING Deutsche Forschungsgemeinschaft, Helmholtz Zentrum München-Deutsches Forschungszentrum für Gesundheit und Umwelt, National Research Institutions, NHS Blood and Transplant, National Institute for Health Research, British Heart Foundation, European Commission, European Research Council, National Institutes of Health, National Institute of Neurological Disorders and Stroke, NIH Research Cambridge Biomedical Research Centre, and UK Medical Research Council.
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Affiliation(s)
- Barbara Schormair
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Chen Zhao
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Steven Bell
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Erik Tilch
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Aaro V Salminen
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Benno Pütz
- Max Planck Institute of Psychiatry, Munich, Germany
| | - Yves Dauvilliers
- Sleep-Wake Disorders Centre, Department of Neurology, Hôpital Gui-de-Chauliac, INSERM U1061, CHU Montpellier, France
| | - Ambra Stefani
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Birgit Högl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - David Kemlink
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Karel Sonka
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | | | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Centre, Georg August University Göttingen, Göttingen, Germany
| | - Claudia Trenkwalder
- Clinic for Neurosurgery, University Medical Centre, Georg August University Göttingen, Göttingen, Germany; Paracelsus-Elena Hospital, Centre of Parkinsonism and Movement Disorders, Kassel, Germany
| | - Wolfgang H Oertel
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany; Department of Neurology, Philipps University Marburg, Marburg, Germany
| | - Magdolna Hornyak
- Department of Neurology, University of Ulm, Ulm, Germany; Neuropsychiatry Centre Erding/München, Erding, Germany
| | - Maris Teder-Laving
- Estonian Genome Centre, University of Tartu and Estonian Biocentre, Tartu, Estonia
| | - Andres Metspalu
- Estonian Genome Centre, University of Tartu and Estonian Biocentre, Tartu, Estonia
| | - Georgios M Hadjigeorgiou
- Laboratory of Neurogenetics, Department of Neurology, Faculty of Medicine, University of Thessaly, University Hospital of Larissa, Biopolis, Larissa, Greece
| | - Olli Polo
- Unesta Research Centre, Tampere, Finland; Department of Pulmonary Diseases, Tampere University Hospital, Tampere, Finland
| | - Ingo Fietze
- Department of Cardiology and Angiology, Centre of Sleep Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Owen A Ross
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | - Adam S Butterworth
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK; British Heart Foundation Centre of Excellence, Division of Cardiovascular Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Nicole Soranzo
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Department of Human Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Willem H Ouwehand
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; NHS Blood and Transplant, Cambridge, UK; British Heart Foundation Centre of Excellence, Division of Cardiovascular Medicine, Addenbrooke's Hospital, Cambridge, UK; Department of Human Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - David J Roberts
- NHS Blood and Transplant, Oxford, UK; Radcliffe Department of Medicine, BRC Haematology Theme and NHS Blood and Transplant, John Radcliffe Hospital, Headington, Oxford, UK; Department of Haematology and BRC Haematology Theme, Churchill Hospital, Oxford, UK
| | - John Danesh
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK; British Heart Foundation Centre of Excellence, Division of Cardiovascular Medicine, Addenbrooke's Hospital, Cambridge, UK; Department of Human Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Richard P Allen
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Christopher J Earley
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - William G Ondo
- Department of Neurology, Methodist Neurological Institute, Houston, TX, USA
| | - Lan Xiong
- Laboratoire de Neurogénétique, Centre de Recherche, Institut Universitaire en Santé Mentale de Montréal, Montréal, QC, Canada; Département de Psychiatrie, Université de Montréal, Montréal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
| | - Jacques Montplaisir
- Département de Psychiatrie, Université de Montréal, Montréal, QC, Canada; Hôpital du Sacré-Coeur de Montréal, 67120, Center for Advanced Research in Sleep Medicine, Montréal, QC, Canada
| | - Ziv Gan-Or
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada; Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Markus Perola
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland; Institute of Molecular Medicine FIMM, University of Helsinki, Helsinki, Finland
| | - Pavel Vodicka
- Department of Molecular Biology of Cancer, Institute of Experimental Medicine, Academy of Science of Czech Republic, Prague, Czech Republic; Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic
| | - Christian Dina
- Inserm UMR1087, CNRS UMR 6291, Institut du Thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) Nantes, Université de Nantes, France
| | - Andre Franke
- Institute of Clinical Molecular Biology, Kiel University, Kiel, Germany
| | - Lukas Tittmann
- PopGen Biobank and Institute of Epidemiology, Christian Albrechts University Kiel, Kiel, Germany
| | - Alexandre F R Stewart
- John and Jennifer Ruddy Canadian Cardiovascular Genetics Centre, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Svati H Shah
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA; Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA
| | - Christian Gieger
- Institute of Epidemiology II, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany; Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany; German Centre for Diabetes Research (DZD), Neuherberg, Germany
| | - Annette Peters
- Institute of Epidemiology II, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany; German Centre for Diabetes Research (DZD), Neuherberg, Germany; German Centre for Cardiovascular Disease Research (DZHK), Berlin, Germany
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada; Department of Human Genetics, McGill University, Montréal, QC, Canada; Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Klaus Berger
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - Konrad Oexle
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Emanuele Di Angelantonio
- National Institute for Health Research Blood and Transplant Unit in Donor Health and Genomics at the University of Cambridge, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, Strangeways Research Laboratory, University of Cambridge, Cambridge, UK; NHS Blood and Transplant, Cambridge, UK; National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK; British Heart Foundation Centre of Excellence, Division of Cardiovascular Medicine, Addenbrooke's Hospital, Cambridge, UK
| | | | - Bertram Müller-Myhsok
- Max Planck Institute of Psychiatry, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; Institute of Human Genetics, Technische Universität München, Munich, Germany; Neurologische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany.
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Biederer T, Kaeser PS, Blanpied TA. Transcellular Nanoalignment of Synaptic Function. Neuron 2017; 96:680-696. [PMID: 29096080 PMCID: PMC5777221 DOI: 10.1016/j.neuron.2017.10.006] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 12/21/2022]
Abstract
At each of the brain's vast number of synapses, the presynaptic nerve terminal, synaptic cleft, and postsynaptic specialization form a transcellular unit to enable efficient transmission of information between neurons. While we know much about the molecular machinery within each compartment, we are only beginning to understand how these compartments are structurally registered and functionally integrated with one another. This review will describe the organization of each compartment and then discuss their alignment across pre- and postsynaptic cells at a nanometer scale. We propose that this architecture may allow for precise synaptic information exchange and may be modulated to contribute to the remarkable plasticity of brain function.
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Affiliation(s)
- Thomas Biederer
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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50
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Jang S, Lee H, Kim E. Synaptic adhesion molecules and excitatory synaptic transmission. Curr Opin Neurobiol 2017; 45:45-50. [DOI: 10.1016/j.conb.2017.03.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/04/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
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