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Wang J, Zhu H, Tian R, Zhang Q, Zhang H, Hu J, Wang S. Physiological and pathological effects of phase separation in the central nervous system. J Mol Med (Berl) 2024; 102:599-615. [PMID: 38441598 PMCID: PMC11055734 DOI: 10.1007/s00109-024-02435-7] [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: 05/01/2023] [Revised: 02/14/2024] [Accepted: 02/20/2024] [Indexed: 04/28/2024]
Abstract
Phase separation, also known as biomolecule condensate, participates in physiological processes such as transcriptional regulation, signal transduction, gene expression, and DNA damage repair by creating a membrane-free compartment. Phase separation is primarily caused by the interaction of multivalent non-covalent bonds between proteins and/or nucleic acids. The strength of molecular multivalent interaction can be modified by component concentration, the potential of hydrogen, posttranslational modification, and other factors. Notably, phase separation occurs frequently in the cytoplasm of mitochondria, the nucleus, and synapses. Phase separation in vivo is dynamic or stable in the normal physiological state, while abnormal phase separation will lead to the formation of biomolecule condensates, speeding up the disease progression. To provide candidate suggestions for the clinical treatment of nervous system diseases, this review, based on existing studies, carefully and systematically represents the physiological roles of phase separation in the central nervous system and its pathological mechanism in neurodegenerative diseases.
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Affiliation(s)
- Jiaxin Wang
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People's Republic of China
- School of Medicine, Xiamen University, Xiamen, Fujian, 361000, People's Republic of China
| | - Hongrui Zhu
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People's Republic of China.
- Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, China.
| | - Ruijia Tian
- School of Medicine, Xiamen University, Xiamen, Fujian, 361000, People's Republic of China
| | - Qian Zhang
- School of Medicine, Xiamen University, Xiamen, Fujian, 361000, People's Republic of China
| | - Haoliang Zhang
- School of Medicine, Xiamen University, Xiamen, Fujian, 361000, People's Republic of China
| | - Jin Hu
- School of Medicine, Xiamen University, Xiamen, Fujian, 361000, People's Republic of China
| | - Sheng Wang
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People's Republic of China.
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2
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Núñez-Carpintero I, Rigau M, Bosio M, O'Connor E, Spendiff S, Azuma Y, Topf A, Thompson R, 't Hoen PAC, Chamova T, Tournev I, Guergueltcheva V, Laurie S, Beltran S, Capella-Gutiérrez S, Cirillo D, Lochmüller H, Valencia A. Rare disease research workflow using multilayer networks elucidates the molecular determinants of severity in Congenital Myasthenic Syndromes. Nat Commun 2024; 15:1227. [PMID: 38418480 PMCID: PMC10902324 DOI: 10.1038/s41467-024-45099-0] [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: 12/21/2022] [Accepted: 01/15/2024] [Indexed: 03/01/2024] Open
Abstract
Exploring the molecular basis of disease severity in rare disease scenarios is a challenging task provided the limitations on data availability. Causative genes have been described for Congenital Myasthenic Syndromes (CMS), a group of diverse minority neuromuscular junction (NMJ) disorders; yet a molecular explanation for the phenotypic severity differences remains unclear. Here, we present a workflow to explore the functional relationships between CMS causal genes and altered genes from each patient, based on multilayer network community detection analysis of complementary biomedical information provided by relevant data sources, namely protein-protein interactions, pathways and metabolomics. Our results show that CMS severity can be ascribed to the personalized impairment of extracellular matrix components and postsynaptic modulators of acetylcholine receptor (AChR) clustering. This work showcases how coupling multilayer network analysis with personalized -omics information provides molecular explanations to the varying severity of rare diseases; paving the way for sorting out similar cases in other rare diseases.
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Affiliation(s)
- Iker Núñez-Carpintero
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain
| | - Maria Rigau
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Mattia Bosio
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain
- Coordination Unit Spanish National Bioinformatics Institute (INB/ELIXIR-ES), Barcelona Supercomputing Center, Barcelona, Spain
| | - Emily O'Connor
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Sally Spendiff
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Yoshiteru Azuma
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Pediatrics, Aichi Medical University, Nagakute, Japan
| | - Ana Topf
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Rachel Thompson
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Peter A C 't Hoen
- Center for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Teodora Chamova
- Department of Neurology, Expert Centre for Hereditary Neurologic and Metabolic Disorders, Alexandrovska University Hospital, Medical University-Sofia, Sofia, Bulgaria
| | - Ivailo Tournev
- Department of Neurology, Expert Centre for Hereditary Neurologic and Metabolic Disorders, Alexandrovska University Hospital, Medical University-Sofia, Sofia, Bulgaria
- Department of Cognitive Science and Psychology, New Bulgarian University, Sofia, 1618, Bulgaria
| | - Velina Guergueltcheva
- Clinic of Neurology, University Hospital Sofiamed, Sofia University St. Kliment Ohridski, Sofia, Bulgaria
| | - Steven Laurie
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Sergi Beltran
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Spain
| | - Salvador Capella-Gutiérrez
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain
- Coordination Unit Spanish National Bioinformatics Institute (INB/ELIXIR-ES), Barcelona Supercomputing Center, Barcelona, Spain
| | - Davide Cirillo
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain.
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada
- Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Alfonso Valencia
- Barcelona Supercomputing Center (BSC), Plaça Eusebi Güell, 1-3, 08034, Barcelona, Spain
- Coordination Unit Spanish National Bioinformatics Institute (INB/ELIXIR-ES), Barcelona Supercomputing Center, Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
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3
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Paul MS, Michener SL, Pan H, Chan H, Pfliger JM, Rosenfeld JA, Lerma VC, Tran A, Longley MA, Lewis RA, Weisz-Hubshman M, Bekheirnia MR, Bekheirnia N, Massingham L, Zech M, Wagner M, Engels H, Cremer K, Mangold E, Peters S, Trautmann J, Mester JL, Guillen Sacoto MJ, Person R, McDonnell PP, Cohen SR, Lusk L, Cohen ASA, Le Pichon JB, Pastinen T, Zhou D, Engleman K, Racine C, Faivre L, Moutton S, Denommé-Pichon AS, Koh HY, Poduri A, Bolton J, Knopp C, Julia Suh DS, Maier A, Toosi MB, Karimiani EG, Maroofian R, Schaefer GB, Ramakumaran V, Vasudevan P, Prasad C, Osmond M, Schuhmann S, Vasileiou G, Russ-Hall S, Scheffer IE, Carvill GL, Mefford H, Bacino CA, Lee BH, Chao HT. A syndromic neurodevelopmental disorder caused by rare variants in PPFIA3. Am J Hum Genet 2024; 111:96-118. [PMID: 38181735 PMCID: PMC10806447 DOI: 10.1016/j.ajhg.2023.12.004] [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: 04/06/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 01/07/2024] Open
Abstract
PPFIA3 encodes the protein-tyrosine phosphatase, receptor-type, F-polypeptide-interacting-protein-alpha-3 (PPFIA3), which is a member of the LAR-protein-tyrosine phosphatase-interacting-protein (liprin) family involved in synapse formation and function, synaptic vesicle transport, and presynaptic active zone assembly. The protein structure and function are evolutionarily well conserved, but human diseases related to PPFIA3 dysfunction are not yet reported in OMIM. Here, we report 20 individuals with rare PPFIA3 variants (19 heterozygous and 1 compound heterozygous) presenting with developmental delay, intellectual disability, hypotonia, dysmorphisms, microcephaly or macrocephaly, autistic features, and epilepsy with reduced penetrance. Seventeen unique PPFIA3 variants were detected in 18 families. To determine the pathogenicity of PPFIA3 variants in vivo, we generated transgenic fruit flies producing either human wild-type (WT) PPFIA3 or five missense variants using GAL4-UAS targeted gene expression systems. In the fly overexpression assays, we found that the PPFIA3 variants in the region encoding the N-terminal coiled-coil domain exhibited stronger phenotypes compared to those affecting the C-terminal region. In the loss-of-function fly assay, we show that the homozygous loss of fly Liprin-α leads to embryonic lethality. This lethality is partially rescued by the expression of human PPFIA3 WT, suggesting human PPFIA3 function is partially conserved in the fly. However, two of the tested variants failed to rescue the lethality at the larval stage and one variant failed to rescue lethality at the adult stage. Altogether, the human and fruit fly data reveal that the rare PPFIA3 variants are dominant-negative loss-of-function alleles that perturb multiple developmental processes and synapse formation.
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Affiliation(s)
- Maimuna S Paul
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Sydney L Michener
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA
| | - Hongling Pan
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Hiuling Chan
- Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA; Augustana College, Rock Island, IL, USA; Summer Undergraduate Research Training (SMART) Program, Baylor College of Medicine, Houston, TX, USA
| | - Jessica M Pfliger
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Graduate Program in Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Vanesa C Lerma
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Department of Psychology, University of Houston, Houston, TX, USA
| | - Alyssa Tran
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Megan A Longley
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Richard A Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Monika Weisz-Hubshman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Mir Reza Bekheirnia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Renal Genetics Clinic, Baylor College of Medicine, Houston, TX, USA
| | - Nasim Bekheirnia
- Renal Genetics Clinic, Baylor College of Medicine, Houston, TX, USA
| | - Lauren Massingham
- Rhode Island Hospital and Hasbro Children's Hospital, Providence, RI, USA
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University, Munich, Germany; Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - Matias Wagner
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany; Institute of Human Genetics, School of Medicine, Technical University, Munich, Germany; Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Hartmut Engels
- Institute of Human Genetics, School of Medicine, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Kirsten Cremer
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Elisabeth Mangold
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Sophia Peters
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | - Jessica Trautmann
- Division of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Dr. von Hauner Children's Hospital, Munich, Germany
| | | | | | | | - Pamela P McDonnell
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stacey R Cohen
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Laina Lusk
- Epilepsy NeuroGenetics Initiative (ENGIN), Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ana S A Cohen
- Children's Mercy Kansas City, Genomic Medicine Center, The University of Missouri-Kansas City (UMKC), School of Medicine, Kansas City, MO, USA
| | | | - Tomi Pastinen
- Children's Mercy Kansas City, Genomic Medicine Center, The University of Missouri-Kansas City (UMKC), School of Medicine, Kansas City, MO, USA; Children's Mercy Research Institute, Kansas City, MO, USA
| | - Dihong Zhou
- Children's Mercy Hospital, Kansas City, MO, USA
| | | | - Caroline Racine
- University Hospital, Dijon, France; INSERM UMR1231 GAD "Génétique des Anomalies Du Développement," FHU-TRANSLAD, University of Burgundy, Dijon, France; Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France
| | - Laurence Faivre
- Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France; Department of Genetics and Reference Center for Development Disorders and Intellectual Disabilities, FHU-TRANSLAD and GIMI Institute, Dijon Bourgogne University Hospital, Dijon, France
| | - Sébastien Moutton
- Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France; Department of Genetics and Reference Center for Development Disorders and Intellectual Disabilities, FHU-TRANSLAD and GIMI Institute, Dijon Bourgogne University Hospital, Dijon, France
| | - Anne-Sophie Denommé-Pichon
- University Hospital, Dijon, France; INSERM UMR1231 GAD "Génétique des Anomalies Du Développement," FHU-TRANSLAD, University of Burgundy, Dijon, France; Functional Unit for Diagnostic Innovation in Rare Diseases, FHU-TRANSLAD, Dijon Bourgogne, France
| | - Hyun Yong Koh
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Jeffrey Bolton
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Cordula Knopp
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH, Aachen University, Aachen, Germany
| | - Dong Sun Julia Suh
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH, Aachen University, Aachen, Germany
| | - Andrea Maier
- Medical Treatment Center for Adults with Intellectual Disabilities and/or Severe Multiple Disabilities (MZEB), RWTH Aachen University Hospital, Aachen, Germany
| | - Mehran Beiraghi Toosi
- Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran; Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, UK
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | | | | | - Pradeep Vasudevan
- LNR Genomics Medicine, University Hospitals of Leicester, Leicester, UK
| | - Chitra Prasad
- London Health Sciences Centre, and Division of Medical Genetics, Department of Pediatrics, Western University, London, ON, Canada
| | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, ON, Canada
| | - Sarah Schuhmann
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Georgia Vasileiou
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Sophie Russ-Hall
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, VIC, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, VIC, Australia; Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, VIC, Melbourne, Australia
| | - Gemma L Carvill
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Heather Mefford
- Center for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Carlos A Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Brendan H Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Hsiao-Tuan Chao
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX, USA.
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Wu S, Fan J, Tang F, Chen L, Zhang X, Xiao D, Li X. The role of RIM in neurotransmitter release: promotion of synaptic vesicle docking, priming, and fusion. Front Neurosci 2023; 17:1123561. [PMID: 37179554 PMCID: PMC10169678 DOI: 10.3389/fnins.2023.1123561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/06/2023] [Indexed: 05/15/2023] Open
Abstract
There are many special sites at the end of a synapse called active zones (AZs). Synaptic vesicles (SVs) fuse with presynaptic membranes at these sites, and this fusion is an important step in neurotransmitter release. The cytomatrix in the active zone (CAZ) is made up of proteins such as the regulating synaptic membrane exocytosis protein (RIM), RIM-binding proteins (RIM-BPs), ELKS/CAST, Bassoon/Piccolo, Liprin-α, and Munc13-1. RIM is a scaffold protein that interacts with CAZ proteins and presynaptic functional components to affect the docking, priming, and fusion of SVs. RIM is believed to play an important role in regulating the release of neurotransmitters (NTs). In addition, abnormal expression of RIM has been detected in many diseases, such as retinal diseases, Asperger's syndrome (AS), and degenerative scoliosis. Therefore, we believe that studying the molecular structure of RIM and its role in neurotransmitter release will help to clarify the molecular mechanism of neurotransmitter release and identify targets for the diagnosis and treatment of the aforementioned diseases.
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Affiliation(s)
- Shanshan Wu
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Jiali Fan
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Fajuan Tang
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Lin Chen
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Xiaoyan Zhang
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Dongqiong Xiao
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
| | - Xihong Li
- Emergency Department, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China
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5
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Paul MS, Michener SL, Pan H, Pfliger JM, Rosenfeld JA, Lerma VC, Tran A, Longley MA, Lewis RA, Weisz-Hubshman M, Bekheirnia MR, Bekheirnia N, Massingham L, Zech M, Wagner M, Engels H, Cremer K, Mangold E, Peters S, Trautmann J, Mester JL, Guillen Sacoto MJ, Person R, McDonnell PP, Cohen SR, Lusk L, Cohen ASA, Pichon JBL, Pastinen T, Zhou D, Engleman K, Racine C, Faivre L, Moutton S, Pichon ASD, Schuhmann S, Vasileiou G, Russ-Hall S, Scheffer IE, Carvill GL, Mefford H, Network UD, Bacino CA, Lee BH, Chao HT. Rare variants in PPFIA3 cause delayed development, intellectual disability, autism, and epilepsy. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.27.23287689. [PMID: 37034625 PMCID: PMC10081396 DOI: 10.1101/2023.03.27.23287689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
PPFIA3 encodes the Protein-Tyrosine Phosphatase, Receptor-Type, F Polypeptide-Interacting Protein Alpha-3 (PPFIA3), which is a member of the LAR protein-tyrosine phosphatase-interacting protein (liprin) family involved in synaptic vesicle transport and presynaptic active zone assembly. The protein structure and function are well conserved in both invertebrates and vertebrates, but human diseases related to PPFIA3 dysfunction are not yet known. Here, we report 14 individuals with rare mono-allelic PPFIA3 variants presenting with features including developmental delay, intellectual disability, hypotonia, autism, and epilepsy. To determine the pathogenicity of PPFIA3 variants in vivo , we generated transgenic fruit flies expressing either human PPFIA3 wildtype (WT) or variant protein using GAL4-UAS targeted gene expression systems. Ubiquitous expression with Actin-GAL4 showed that the PPFIA3 variants had variable penetrance of pupal lethality, eclosion defects, and anatomical leg defects. Neuronal expression with elav-GAL4 showed that the PPFIA3 variants had seizure-like behaviors, motor defects, and bouton loss at the 3 rd instar larval neuromuscular junction (NMJ). Altogether, in the fly overexpression assays, we found that the PPFIA3 variants in the N-terminal coiled coil domain exhibited stronger phenotypes compared to those in the C-terminal region. In the loss-of-function fly assay, we show that the homozygous loss of fly Liprin- α leads to embryonic lethality. This lethality is partially rescued by the expression of human PPFIA3 WT, suggesting human PPFIA3 protein function is partially conserved in the fly. However, the PPFIA3 variants failed to rescue lethality. Altogether, the human and fruit fly data reveal that the rare PPFIA3 variants are dominant negative loss-of-function alleles that perturb multiple developmental processes and synapse formation.
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6
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Waqas A, Liaqat R, Shaheen S, Khan AZ, Habib AH, Binothman N, Aljadani M, Zehri Z, Shaheen S, Alkathiri A, Naz R, Umair M, Abbas S. A novel homozygous truncating variant in PPFIBP1 further delineates PPFIBP1-associated neurodevelopmental disorder. Int J Dev Neurosci 2022; 83:191-200. [PMID: 36527195 DOI: 10.1002/jdn.10247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/21/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Neurodevelopmental disorders (NDDs) are classified as a group of disorders affecting function and development of the brain and having wide clinical variability. Herein, we describe two affected individuals segregating a recessive NDD. The affected individuals exhibited phenotypes such as global developmental delay (GDD), intellectual disability (ID), microcephaly and speech delay. Whole-exome sequencing (WES) followed by bidirectional Sanger sequencing techniques identified a homozygous nonsense variant (c.466C > T; p.Gln156*) in the PPFIBP1 gene (NM_003622.4) that segregated with the disease phenotype. Further, to elucidate the effect of the variant on protein structure, 3D protein modelling was performed for the mutant and normal protein that suggested substantial reduction of the mutant protein. Our data support the evidence that PPFIBP1 has a pivotal role in neurodevelopment in humans, and loss-of-function variants cause clinically variable neurodevelopmental phenotypes.
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Affiliation(s)
- Ahmed Waqas
- Department Zoology, Division of Science and Technology, University of Education, Lahore, Punjab, Pakistan
| | - Romana Liaqat
- Institute of Chemical Science, Gomal University, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan
| | - Sidrah Shaheen
- Department of Higher Education, Government Girls degree College No. 1, Mansehra, Khyber Pakhtunkhwa, Pakistan
| | - Ali Zaman Khan
- Department of Surgery, Surgical Ward 'A', Khyber Teaching Hospital, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Alaa Hamed Habib
- Department of Physiology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Najat Binothman
- Department of Chemistry, College of Sciences and Arts, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Majidah Aljadani
- Department of Chemistry, College of Sciences and Arts, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Zamrud Zehri
- Shaheed Nawab Ghous Bakhsh Raisani Memorial Hospital, Mastung, Balochistan, Pakistan
| | - Shabnam Shaheen
- Department of Higher Education, Government Girls Degree College, Lakki Marwat, Khyber Pakhtunkhwa, Pakistan
| | - Afnan Alkathiri
- Medical Genetics, Laboratory Medicine Department, Faculty of Applied Medical Sciences, Albaha University, Albaha, Saudi Arabia
| | - Rubina Naz
- Institute of Chemical Science, Gomal University, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Umair
- Department of Life Sciences, School of Science, University of Management and Technology, Lahore, Punjab, Pakistan
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGH), Riyadh, Saudi Arabia
| | - Safdar Abbas
- Department of Biological Science, Dartmouth College, Hanover, NH, USA
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7
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Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications. Am J Hum Genet 2022; 109:1421-1435. [PMID: 35830857 PMCID: PMC9388382 DOI: 10.1016/j.ajhg.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/13/2022] [Indexed: 02/06/2023] Open
Abstract
PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.
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8
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Losada-Pérez M, Hernández García-Moreno M, García-Ricote I, Casas-Tintó S. Synaptic components are required for glioblastoma progression in Drosophila. PLoS Genet 2022; 18:e1010329. [PMID: 35877760 PMCID: PMC9352205 DOI: 10.1371/journal.pgen.1010329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 08/04/2022] [Accepted: 07/06/2022] [Indexed: 11/18/2022] Open
Abstract
Glioblastoma (GB) is the most aggressive, lethal and frequent primary brain tumor. It originates from glial cells and is characterized by rapid expansion through infiltration. GB cells interact with the microenvironment and healthy surrounding tissues, mostly neurons and vessels. GB cells project tumor microtubes (TMs) contact with neurons, and exchange signaling molecules related to Wingless/WNT, JNK, Insulin or Neuroligin-3 pathways. This cell to cell communication promotes GB expansion and neurodegeneration. Moreover, healthy neurons form glutamatergic functional synapses with GB cells which facilitate GB expansion and premature death in mouse GB xerograph models. Targeting signaling and synaptic components of GB progression may become a suitable strategy against glioblastoma. In a Drosophila GB model, we have determined the post-synaptic nature of GB cells with respect to neurons, and the contribution of post-synaptic genes expressed in GB cells to tumor progression. In addition, we document the presence of intratumoral synapses between GB cells, and the functional contribution of pre-synaptic genes to GB calcium dependent activity and expansion. Finally, we explore the relevance of synaptic genes in GB cells to the lifespan reduction caused by GB advance. Our results indicate that both presynaptic and postsynaptic proteins play a role in GB progression and lethality. Glioblastoma (GB) is the most frequent and aggressive type of brain tumor. It is originated from glial cells that expand and proliferate very fast in the brain. GB cells infiltrate and establish cell to cell communication with healthy neurons. Currently there is no effective treatment for GB and these tumors result incurable with an average survival of 16 months after diagnosis. Here we used a Drosophila melanogaster model to search for genetic suppressors of GB progression. The results show that genes involved in the formation of synapses are required for glial cell number increase, expansion of tumoral volume and premature death. Among these synaptic genes we found that post-synaptic genes that contribute to Neuron-GB interaction which validate previous findings in human GB. Moreover, we found electro dense structures between GB cells that are compatible with synapses and that expression of pre-synaptic genes, including brp, Lip-α and syt 1, is required for GB progression and aggressiveness. These results suggest a contribution of synapses between GB cells to disease progression, named as intratumoral synapses.
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Affiliation(s)
| | | | | | - Sergio Casas-Tintó
- Instituto Cajal-CSIC, Madrid, Spain
- IIER-Instituto de Salud CarlosIII, Majadahonda, Spain
- * E-mail:
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9
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Duhart JC, Mosca TJ. Genetic regulation of central synapse formation and organization in Drosophila melanogaster. Genetics 2022; 221:6597078. [PMID: 35652253 DOI: 10.1093/genetics/iyac078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/29/2022] [Indexed: 01/04/2023] Open
Abstract
A goal of modern neuroscience involves understanding how connections in the brain form and function. Such a knowledge is essential to inform how defects in the exquisite complexity of nervous system growth influence neurological disease. Studies of the nervous system in the fruit fly Drosophila melanogaster enabled the discovery of a wealth of molecular and genetic mechanisms underlying development of synapses-the specialized cell-to-cell connections that comprise the essential substrate for information flow and processing in the nervous system. For years, the major driver of knowledge was the neuromuscular junction due to its ease of examination. Analogous studies in the central nervous system lagged due to a lack of genetic accessibility of specific neuron classes, synaptic labels compatible with cell-type-specific access, and high resolution, quantitative imaging strategies. However, understanding how central synapses form remains a prerequisite to understanding brain development. In the last decade, a host of new tools and techniques extended genetic studies of synapse organization into central circuits to enhance our understanding of synapse formation, organization, and maturation. In this review, we consider the current state-of-the-field. We first discuss the tools, technologies, and strategies developed to visualize and quantify synapses in vivo in genetically identifiable neurons of the Drosophila central nervous system. Second, we explore how these tools enabled a clearer understanding of synaptic development and organization in the fly brain and the underlying molecular mechanisms of synapse formation. These studies establish the fly as a powerful in vivo genetic model that offers novel insights into neural development.
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Affiliation(s)
- Juan Carlos Duhart
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Timothy J Mosca
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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10
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Liprins in oncogenic signaling and cancer cell adhesion. Oncogene 2021; 40:6406-6416. [PMID: 34654889 PMCID: PMC8602034 DOI: 10.1038/s41388-021-02048-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/21/2021] [Accepted: 09/28/2021] [Indexed: 12/30/2022]
Abstract
Liprins are a multifunctional family of scaffold proteins, identified by their involvement in several important neuronal functions related to signaling and organization of synaptic structures. More recently, the knowledge on the liprin family has expanded from neuronal functions to processes relevant to cancer progression, including cell adhesion, cell motility, cancer cell invasion, and signaling. These proteins consist of regions, which by prediction are intrinsically disordered, and may be involved in the assembly of supramolecular structures relevant for their functions. This review summarizes the current understanding of the functions of liprins in different cellular processes, with special emphasis on liprins in tumor progression. The available data indicate that liprins may be potential biomarkers for cancer progression and may have therapeutic importance.
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11
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Oh KH, Krout MD, Richmond JE, Kim H. UNC-2 CaV2 Channel Localization at Presynaptic Active Zones Depends on UNC-10/RIM and SYD-2/Liprin-α in Caenorhabditis elegans. J Neurosci 2021; 41:4782-4794. [PMID: 33975919 PMCID: PMC8260173 DOI: 10.1523/jneurosci.0076-21.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/07/2021] [Accepted: 04/29/2021] [Indexed: 12/20/2022] Open
Abstract
Presynaptic active zone proteins couple calcium influx with synaptic vesicle exocytosis. However, the control of presynaptic calcium channel localization by active zone proteins is not completely understood. In a Caenorhabditis elegans (C. elegans) forward genetic screen, we find that UNC-10/RIM (Rab3-interacting molecule) and SYD-2/Liprin-α regulate presynaptic localization of UNC-2, the CaV2 channel ortholog. We further quantitatively analyzed live animals using endogenously GFP-tagged UNC-2 and active zone components. Consistent with the interaction between RIM and CaV2 in mammals, the intensity and number of UNC-2 channel puncta at presynaptic terminals were greatly reduced in unc-10 mutant animals. To understand how SYD-2 regulates presynaptic UNC-2 channel localization, we analyzed presynaptic localization of endogenous SYD-2, UNC-10, RIMB-1/RIM-BP (RIM binding protein), and ELKS-1. Our analysis revealed that although SYD-2 is the most critical for active zone assembly, loss of SYD-2 function does not completely abolish presynaptic localization of UNC-10, RIMB-1, and ELKS-1, suggesting an existence of SYD-2-independent active zone assembly. UNC-2 localization analysis in double and triple mutants of active zone components show that SYD-2 promotes UNC-2 localization by partially controlling UNC-10 localization, and ELKS-1 and RIMB-1 also contribute to UNC-2 channel localization. In addition, we find that core active zone proteins are unequal in their abundance. Although the abundance of UNC-10 at the active zone is comparable to UNC-2, SYD-2 and ELKS-1 are twice more and RIMB-1 four times more abundant than UNC-2. Together our data show that UNC-10, SYD-2, RIMB-1, and ELKS-1 control presynaptic UNC-2 channel localization in redundant yet distinct manners.SIGNIFICANCE STATEMENT Precise control of neurotransmission is dependent on the tight coupling of the calcium influx through voltage-gated calcium channels (VGCCs) to the exocytosis machinery at the presynaptic active zones. However, how these VGCCs are tethered to the active zone is incompletely understood. To understand the mechanism of presynaptic VGCC localization, we performed a C. elegans forward genetic screen and quantitatively analyzed endogenous active zones and presynaptic VGCCs. In addition to RIM, our study finds that SYD-2/Liprin-α is critical for presynaptic localization of VGCCs. Yet, the loss of SYD-2, a core active zone scaffolding protein, does not completely abolish the presynaptic localization of the VGCC, showing that the active zone is a resilient structure assembled by redundant mechanisms.
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Affiliation(s)
- Kelly H Oh
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064
| | - Mia D Krout
- Department of Biological Science, University of Illinois at Chicago, Chicago, Illinois 60607
| | - Janet E Richmond
- Department of Biological Science, University of Illinois at Chicago, Chicago, Illinois 60607
| | - Hongkyun Kim
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064
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12
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Xie X, Liang M, Yu C, Wei Z. Liprin-α-Mediated Assemblies and Their Roles in Synapse Formation. Front Cell Dev Biol 2021; 9:653381. [PMID: 33869211 PMCID: PMC8044993 DOI: 10.3389/fcell.2021.653381] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 02/25/2021] [Indexed: 01/20/2023] Open
Abstract
Brain's functions, such as memory and learning, rely on synapses that are highly specialized cellular junctions connecting neurons. Functional synapses orchestrate the assembly of ion channels, receptors, enzymes, and scaffold proteins in both pre- and post-synapse. Liprin-α proteins are master scaffolds in synapses and coordinate various synaptic proteins to assemble large protein complexes. The functions of liprin-αs in synapse formation have been largely uncovered by genetic studies in diverse model systems. Recently, emerging structural and biochemical studies on liprin-α proteins and their binding partners begin to unveil the molecular basis of the synaptic assembly. This review summarizes the recent structural findings on liprin-αs, proposes the assembly mechanism of liprin-α-mediated complexes, and discusses the liprin-α-organized assemblies in the regulation of synapse formation and function.
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Affiliation(s)
- Xingqiao Xie
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
| | - Mingfu Liang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Cong Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, China
| | - Zhiyi Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
- Brain Research Center, Southern University of Science and Technology, Shenzhen, China
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13
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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: 12] [Impact Index Per Article: 3.0] [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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14
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Chou VT, Johnson SA, Van Vactor D. Synapse development and maturation at the drosophila neuromuscular junction. Neural Dev 2020; 15:11. [PMID: 32741370 PMCID: PMC7397595 DOI: 10.1186/s13064-020-00147-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
Synapses are the sites of neuron-to-neuron communication and form the basis of the neural circuits that underlie all animal cognition and behavior. Chemical synapses are specialized asymmetric junctions between a presynaptic neuron and a postsynaptic target that form through a series of diverse cellular and subcellular events under the control of complex signaling networks. Once established, the synapse facilitates neurotransmission by mediating the organization and fusion of synaptic vesicles and must also retain the ability to undergo plastic changes. In recent years, synaptic genes have been implicated in a wide array of neurodevelopmental disorders; the individual and societal burdens imposed by these disorders, as well as the lack of effective therapies, motivates continued work on fundamental synapse biology. The properties and functions of the nervous system are remarkably conserved across animal phyla, and many insights into the synapses of the vertebrate central nervous system have been derived from studies of invertebrate models. A prominent model synapse is the Drosophila melanogaster larval neuromuscular junction, which bears striking similarities to the glutamatergic synapses of the vertebrate brain and spine; further advantages include the simplicity and experimental versatility of the fly, as well as its century-long history as a model organism. Here, we survey findings on the major events in synaptogenesis, including target specification, morphogenesis, and the assembly and maturation of synaptic specializations, with a emphasis on work conducted at the Drosophila neuromuscular junction.
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Affiliation(s)
- Vivian T Chou
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Seth A Johnson
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
| | - David Van Vactor
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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15
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Paskus JD, Herring BE, Roche KW. Kalirin and Trio: RhoGEFs in Synaptic Transmission, Plasticity, and Complex Brain Disorders. Trends Neurosci 2020; 43:505-518. [PMID: 32513570 DOI: 10.1016/j.tins.2020.05.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/15/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023]
Abstract
Changes in the actin cytoskeleton are a primary mechanism mediating the morphological and functional plasticity that underlies learning and memory. The synaptic Ras homologous (Rho) guanine nucleotide exchange factors (GEFs) Kalirin and Trio have emerged as central regulators of actin dynamics at the synapse. The increased attention surrounding Kalirin and Trio stems from the growing evidence for their roles in the etiology of a wide range of neurodevelopmental and neurodegenerative disorders. In this Review, we discuss recent findings revealing the unique and diverse functions of these paralog proteins in neurodevelopment, excitatory synaptic transmission, and plasticity. We additionally survey the growing literature implicating these proteins in various neurological disorders.
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Affiliation(s)
- Jeremiah D Paskus
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, USA.
| | - Bruce E Herring
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, USA.
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16
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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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17
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Xie X, Luo L, Liang M, Zhang W, Zhang T, Yu C, Wei Z. Structural basis of liprin-α-promoted LAR-RPTP clustering for modulation of phosphatase activity. Nat Commun 2020; 11:169. [PMID: 31924785 PMCID: PMC6954185 DOI: 10.1038/s41467-019-13949-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/10/2019] [Indexed: 02/08/2023] Open
Abstract
Leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) are cell adhesion molecules involved in mediating neuronal development. The binding of LAR-RPTPs to extracellular ligands induces local clustering of LAR-RPTPs to regulate axon growth and synaptogenesis. LAR-RPTPs interact with synaptic liprin-α proteins via the two cytoplasmic phosphatase domains, D1 and D2. Here we solve the crystal structure of LAR_D1D2 in complex with the SAM repeats of liprin-α3, uncovering a conserved two-site binding mode. Cellular analysis shows that liprin-αs robustly promote clustering of LAR in cells by both the liprin-α/LAR interaction and the oligomerization of liprin-α. Structural analysis reveals a unique homophilic interaction of LAR via the catalytically active D1 domains. Disruption of the D1/D1 interaction diminishes the liprin-α-promoted LAR clustering and increases tyrosine dephosphorylation, demonstrating that the phosphatase activity of LAR is negatively regulated by forming clusters. Additionally, we find that the binding of LAR to liprin-α allosterically regulates the liprin-α/liprin-β interaction. Leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) mediate guided axon growth and synapse formation and liprin-α proteins are their intracellular binding partners. Here the authors present the crystal structure of the phosphatase domains from the LAR-RPTP family member LAR bound to the SAM repeats of liprin-α3 and show that liprin-α binding enhances LAR cluster formation and reduces LAR phosphatase activity in cells.
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Affiliation(s)
- Xingqiao Xie
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.,Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Ling Luo
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Mingfu Liang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Wenchao Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Ting Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.,Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Cong Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.,Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, 518055, China
| | - Zhiyi Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China. .,Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
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18
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Flora P, Wong-Deyrup SW, Martin ET, Palumbo RJ, Nasrallah M, Oligney A, Blatt P, Patel D, Fuchs G, Rangan P. Sequential Regulation of Maternal mRNAs through a Conserved cis-Acting Element in Their 3' UTRs. Cell Rep 2019; 25:3828-3843.e9. [PMID: 30590052 PMCID: PMC6328254 DOI: 10.1016/j.celrep.2018.12.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/28/2018] [Accepted: 11/30/2018] [Indexed: 12/31/2022] Open
Abstract
Maternal mRNAs synthesized during oogenesis initiate the development of future generations. Some maternal mRNAs are either somatic or germline determinants and must be translationally repressed until embryogenesis. However, the translational repressors themselves are temporally regulated. We used polar granule component (pgc), a Drosophila maternal mRNA, to ask how maternal transcripts are repressed while the regulatory landscape is shifting. pgc, a germline determinant, is translationally regulated throughout oogenesis. We find that different conserved RNA-binding proteins bind a 10-nt sequence in the 3′ UTR of pgc mRNA to continuously repress translation at different stages of oogenesis. Pumilio binds to this sequence in undifferentiated and early-differentiating oocytes to block Pgc translation. After differentiation, Bruno levels increase, allowing Bruno to bind the same sequence and take over translational repression of pgc mRNA. We have identified a class of maternal mRNAs that are regulated similarly, including zelda, the activator of the zygotic genome. Flora et al. show that pgc, a germline determinant, is translationally regulated throughout oogenesis. Different conserved RBPs bind a 10-nt sequence in the 3′ UTR to continuously repress translation throughout oogenesis. This mode of regulation applies to a class of maternal mRNAs, including zelda, the activator of the zygotic genome.
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Affiliation(s)
- Pooja Flora
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Siu Wah Wong-Deyrup
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Elliot Todd Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Ryan J Palumbo
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Mohamad Nasrallah
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Andrew Oligney
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Patrick Blatt
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Dhruv Patel
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Gabriele Fuchs
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222, USA.
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19
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Williams-Simon PA, Posey C, Mitchell S, Ng'oma E, Mrkvicka JA, Zars T, King EG. Multiple genetic loci affect place learning and memory performance in Drosophila melanogaster. GENES, BRAIN, AND BEHAVIOR 2019; 18:e12581. [PMID: 31095869 PMCID: PMC6718298 DOI: 10.1111/gbb.12581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/25/2022]
Abstract
Learning and memory are critical functions for all animals, giving individuals the ability to respond to changes in their environment. Within populations, individuals vary, however the mechanisms underlying this variation in performance are largely unknown. Thus, it remains to be determined what genetic factors cause an individual to have high learning ability and what factors determine how well an individual will remember what they have learned. To genetically dissect learning and memory performance, we used the Drosophila synthetic population resource (DSPR), a multiparent mapping resource in the model system Drosophila melanogaster, consisting of a large set of recombinant inbred lines (RILs) that naturally vary in these and other traits. Fruit flies can be trained in a "heat box" to learn to remain on one side of a chamber (place learning) and can remember this (place memory) over short timescales. Using this paradigm, we measured place learning and memory for ~49 000 individual flies from over 700 DSPR RILs. We identified 16 different loci across the genome that significantly affect place learning and/or memory performance, with 5 of these loci affecting both traits. To identify transcriptomic differences associated with performance, we performed RNA-Seq on pooled samples of seven high performing and seven low performing RILs for both learning and memory and identified hundreds of genes with differences in expression in the two sets. Integrating our transcriptomic results with the mapping results allowed us to identify nine promising candidate genes, advancing our understanding of the genetic basis underlying natural variation in learning and memory performance.
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Affiliation(s)
| | - Christopher Posey
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Samuel Mitchell
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Enoch Ng'oma
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - James A Mrkvicka
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Troy Zars
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
| | - Elizabeth G King
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
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20
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Özel MN, Kulkarni A, Hasan A, Brummer J, Moldenhauer M, Daumann IM, Wolfenberg H, Dercksen VJ, Kiral FR, Weiser M, Prohaska S, von Kleist M, Hiesinger PR. Serial Synapse Formation through Filopodial Competition for Synaptic Seeding Factors. Dev Cell 2019; 50:447-461.e8. [PMID: 31353313 DOI: 10.1016/j.devcel.2019.06.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/15/2019] [Accepted: 06/21/2019] [Indexed: 11/15/2022]
Abstract
Following axon pathfinding, growth cones transition from stochastic filopodial exploration to the formation of a limited number of synapses. How the interplay of filopodia and synapse assembly ensures robust connectivity in the brain has remained a challenging problem. Here, we developed a new 4D analysis method for filopodial dynamics and a data-driven computational model of synapse formation for R7 photoreceptor axons in developing Drosophila brains. Our live data support a "serial synapse formation" model, where at any time point only 1-2 "synaptogenic" filopodia suppress the synaptic competence of other filopodia through competition for synaptic seeding factors. Loss of the synaptic seeding factors Syd-1 and Liprin-α leads to a loss of this suppression, filopodial destabilization, and reduced synapse formation. The failure to form synapses can cause the destabilization and secondary retraction of axon terminals. Our model provides a filopodial "winner-takes-all" mechanism that ensures the formation of an appropriate number of synapses.
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Affiliation(s)
- M Neset Özel
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany; Neuroscience Graduate Program, UT Southwestern Medical Center Dallas, Dallas, TX 75390, USA
| | - Abhishek Kulkarni
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Amr Hasan
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Josephine Brummer
- Department of Visual Data Analysis, Zuse Institute Berlin, 14195 Berlin, Germany
| | - Marian Moldenhauer
- Computational Medicine and Numerical Mathematics, Zuse Institute Berlin, 14195 Berlin, Germany; Department of Mathematics and Informatics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ilsa-Maria Daumann
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Heike Wolfenberg
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Vincent J Dercksen
- Department of Visual Data Analysis, Zuse Institute Berlin, 14195 Berlin, Germany
| | - F Ridvan Kiral
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Martin Weiser
- Computational Medicine and Numerical Mathematics, Zuse Institute Berlin, 14195 Berlin, Germany
| | - Steffen Prohaska
- Department of Visual Data Analysis, Zuse Institute Berlin, 14195 Berlin, Germany
| | - Max von Kleist
- Department of Mathematics and Informatics, Freie Universität Berlin, 14195 Berlin, Germany.
| | - P Robin Hiesinger
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany.
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21
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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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22
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Han KA, Um JW, Ko J. Intracellular protein complexes involved in synapse assembly in presynaptic neurons. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 116:347-373. [PMID: 31036296 DOI: 10.1016/bs.apcsb.2018.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The presynaptic active zone, composed of evolutionarily conserved protein complexes, is a specialized area that serves to orchestrate precise and efficient neurotransmitter release by organizing various presynaptic proteins involved in mediating docking and priming of synaptic vesicles, recruiting voltage-gated calcium channels, and modulating presynaptic nerve terminals with aligned postsynaptic structures. Among membrane proteins localized to active zone, presynaptic neurexins and LAR-RPTPs (leukocyte common antigen-related receptor tyrosine phosphatase) have emerged as hubs that orchestrate both shared and distinct extracellular synaptic adhesion pathways. In this chapter, we discuss intracellular signaling cascades involved in recruiting various intracellular proteins at both excitatory and inhibitory synaptic sites. In particular, we highlight recent studies on key active zone proteins that physically and functionally link these cascades with neurexins and LAR-RPTPs in both vertebrate and invertebrate model systems. These studies allow us to build a general, universal view of how presynaptic active zones operate together with postsynaptic structures in neural circuits.
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Affiliation(s)
- Kyung Ah Han
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea.
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23
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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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24
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Liprin-α3 controls vesicle docking and exocytosis at the active zone of hippocampal synapses. Proc Natl Acad Sci U S A 2018; 115:2234-2239. [PMID: 29439199 DOI: 10.1073/pnas.1719012115] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The presynaptic active zone provides sites for vesicle docking and release at central nervous synapses and is essential for speed and accuracy of synaptic transmission. Liprin-α binds to several active zone proteins, and loss-of-function studies in invertebrates established important roles for Liprin-α in neurodevelopment and active zone assembly. However, Liprin-α localization and functions in vertebrates have remained unclear. We used stimulated emission depletion superresolution microscopy to systematically determine the localization of Liprin-α2 and Liprin-α3, the two predominant Liprin-α proteins in the vertebrate brain, relative to other active-zone proteins. Both proteins were widely distributed in hippocampal nerve terminals, and Liprin-α3, but not Liprin-α2, had a prominent component that colocalized with the active-zone proteins Bassoon, RIM, Munc13, RIM-BP, and ELKS. To assess Liprin-α3 functions, we generated Liprin-α3-KO mice by using CRISPR/Cas9 gene editing. We found reduced synaptic vesicle tethering and docking in hippocampal neurons of Liprin-α3-KO mice, and synaptic vesicle exocytosis was impaired. Liprin-α3 KO also led to mild alterations in active zone structure, accompanied by translocation of Liprin-α2 to active zones. These findings establish important roles for Liprin-α3 in active-zone assembly and function, and suggest that interplay between various Liprin-α proteins controls their active-zone localization.
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25
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Astigarraga S, Douthit J, Tarnogorska D, Creamer MS, Mano O, Clark DA, Meinertzhagen IA, Treisman JE. Drosophila Sidekick is required in developing photoreceptors to enable visual motion detection. Development 2018; 145:dev.158246. [PMID: 29361567 DOI: 10.1242/dev.158246] [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: 08/07/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022]
Abstract
The assembly of functional neuronal circuits requires growth cones to extend in defined directions and recognize the correct synaptic partners. Homophilic adhesion between vertebrate Sidekick proteins promotes synapse formation between retinal neurons involved in visual motion detection. We show here that Drosophila Sidekick accumulates in specific synaptic layers of the developing motion detection circuit and is necessary for normal optomotor behavior. Sidekick is required in photoreceptors, but not in their target lamina neurons, to promote the alignment of lamina neurons into columns and subsequent sorting of photoreceptor axons into synaptic modules based on their precise spatial orientation. Sidekick is also localized to the dendrites of the direction-selective T4 and T5 cells, and is expressed in some of their presynaptic partners. In contrast to its vertebrate homologs, Sidekick is not essential for T4 and T5 to direct their dendrites to the appropriate layers or to receive synaptic contacts. These results illustrate a conserved requirement for Sidekick proteins in establishing visual motion detection circuits that is achieved through distinct cellular mechanisms in Drosophila and vertebrates.
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Affiliation(s)
- Sergio Astigarraga
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Jessica Douthit
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Dorota Tarnogorska
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - Matthew S Creamer
- Interdepartmental Neuroscience Program, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Omer Mano
- Department of Molecular, Cellular and Developmental Biology, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Damon A Clark
- Interdepartmental Neuroscience Program, Yale University, Kline Biology Tower Room 224, 219 Whitney Avenue, New Haven, CT 06511, USA
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - Jessica E Treisman
- Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
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26
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Brown LN, Xing Y, Noble KV, Barth JL, Panganiban CH, Smythe NM, Bridges MC, Zhu J, Lang H. Macrophage-Mediated Glial Cell Elimination in the Postnatal Mouse Cochlea. Front Mol Neurosci 2017; 10:407. [PMID: 29375297 PMCID: PMC5770652 DOI: 10.3389/fnmol.2017.00407] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/23/2017] [Indexed: 12/20/2022] Open
Abstract
Hearing relies on the transmission of auditory information from sensory hair cells (HCs) to the brain through the auditory nerve. This relay of information requires HCs to be innervated by spiral ganglion neurons (SGNs) in an exclusive manner and SGNs to be ensheathed by myelinating and non-myelinating glial cells. In the developing auditory nerve, mistargeted SGN axons are retracted or pruned and excessive cells are cleared in a process referred to as nerve refinement. Whether auditory glial cells are eliminated during auditory nerve refinement is unknown. Using early postnatal mice of either sex, we show that glial cell numbers decrease after the first postnatal week, corresponding temporally with nerve refinement in the developing auditory nerve. Additionally, expression of immune-related genes was upregulated and macrophage numbers increase in a manner coinciding with the reduction of glial cell numbers. Transient depletion of macrophages during early auditory nerve development, using transgenic CD11bDTR/EGFP mice, resulted in the appearance of excessive glial cells. Macrophage depletion caused abnormalities in myelin formation and transient edema of the stria vascularis. Macrophage-depleted mice also showed auditory function impairment that partially recovered in adulthood. These findings demonstrate that macrophages contribute to the regulation of glial cell number during postnatal development of the cochlea and that glial cells play a critical role in hearing onset and auditory nerve maturation.
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Affiliation(s)
- LaShardai N. Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Yazhi Xing
- Department of Otorhinolaryngology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China
| | - Kenyaria V. Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Jeremy L. Barth
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Clarisse H. Panganiban
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Nancy M. Smythe
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Mary C. Bridges
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Juhong Zhu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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27
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Flora P, Schowalter S, Wong-Deyrup S, DeGennaro M, Nasrallah MA, Rangan P. Transient transcriptional silencing alters the cell cycle to promote germline stem cell differentiation in Drosophila. Dev Biol 2017; 434:84-95. [PMID: 29198563 PMCID: PMC5830152 DOI: 10.1016/j.ydbio.2017.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/18/2017] [Accepted: 11/27/2017] [Indexed: 12/31/2022]
Abstract
Transcriptional silencing is a conserved process used by embryonic germ cells to repress somatic fate and maintain totipotency and immortality. In Drosophila, this transcriptional silencing is mediated by polar granule component (pgc). Here, we show that in the adult ovary, pgc is required for timely germline stem cell (GSC) differentiation. Pgc is expressed transiently in the immediate GSC daughter (pre-cystoblast), where it mediates a pulse of transcriptional silencing. This transcriptional silencing mediated by pgc indirectly promotes the accumulation of Cyclin B (CycB) and cell cycle progression into late-G2 phase, when the differentiation factor bag of marbles (bam) is expressed. Pgc mediated accumulation of CycB is also required for heterochromatin deposition, which protects the germ line genome against selfish DNA elements. Our results suggest that transient transcriptional silencing in the pre-cystoblast “re-programs” it away from self-renewal and toward the gamete differentiation program.
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Affiliation(s)
- Pooja Flora
- Department of Biological Sciences/The RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Sean Schowalter
- Department of Biological Sciences/The RNA Institute, University at Albany SUNY, Albany, NY 12222, USA; Boston University School of Medicine, 815 Albany Street, MA 02119, USA
| | - SiuWah Wong-Deyrup
- Department of Biological Sciences/The RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Matthew DeGennaro
- Biomolecular Sciences Institute, Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
| | - Mohamad Ali Nasrallah
- Department of Biological Sciences/The RNA Institute, University at Albany SUNY, Albany, NY 12222, USA; University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Prashanth Rangan
- Department of Biological Sciences/The RNA Institute, University at Albany SUNY, Albany, NY 12222, USA.
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28
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Plazaola-Sasieta H, Fernández-Pineda A, Zhu Q, Morey M. Untangling the wiring of the Drosophila visual system: developmental principles and molecular strategies. J Neurogenet 2017; 31:231-249. [DOI: 10.1080/01677063.2017.1391249] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Haritz Plazaola-Sasieta
- Department of Genetics, Microbiology and Statistics; School of Biology and Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Alejandra Fernández-Pineda
- Department of Genetics, Microbiology and Statistics; School of Biology and Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Qi Zhu
- Department of Genetics, Microbiology and Statistics; School of Biology and Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Marta Morey
- Department of Genetics, Microbiology and Statistics; School of Biology and Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
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29
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Zappulo A, van den Bruck D, Ciolli Mattioli C, Franke V, Imami K, McShane E, Moreno-Estelles M, Calviello L, Filipchyk A, Peguero-Sanchez E, Müller T, Woehler A, Birchmeier C, Merino E, Rajewsky N, Ohler U, Mazzoni EO, Selbach M, Akalin A, Chekulaeva M. RNA localization is a key determinant of neurite-enriched proteome. Nat Commun 2017; 8:583. [PMID: 28928394 PMCID: PMC5605627 DOI: 10.1038/s41467-017-00690-6] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 07/19/2017] [Indexed: 11/09/2022] Open
Abstract
Protein subcellular localization is fundamental to the establishment of the body axis, cell migration, synaptic plasticity, and a vast range of other biological processes. Protein localization occurs through three mechanisms: protein transport, mRNA localization, and local translation. However, the relative contribution of each process to neuronal polarity remains unknown. Using neurons differentiated from mouse embryonic stem cells, we analyze protein and RNA expression and translation rates in isolated cell bodies and neurites genome-wide. We quantify 7323 proteins and the entire transcriptome, and identify hundreds of neurite-localized proteins and locally translated mRNAs. Our results demonstrate that mRNA localization is the primary mechanism for protein localization in neurites that may account for half of the neurite-localized proteome. Moreover, we identify multiple neurite-targeted non-coding RNAs and RNA-binding proteins with potential regulatory roles. These results provide further insight into the mechanisms underlying the establishment of neuronal polarity. Subcellular localization of RNAs and proteins is important for polarized cells such as neurons. Here the authors differentiate mouse embryonic stem cells into neurons, and analyze the local transcriptome, proteome, and translated transcriptome in their cell bodies and neurites, providing a unique resource for future studies on neuronal polarity.
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Affiliation(s)
- Alessandra Zappulo
- Non-coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - David van den Bruck
- Non-coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Camilla Ciolli Mattioli
- Non-coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Vedran Franke
- BIMSB Bioinformatics Platform, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Koshi Imami
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Erik McShane
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | | | - Lorenzo Calviello
- Computational Regulatory Genomics, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Andrei Filipchyk
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Esteban Peguero-Sanchez
- Non-coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany.,Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Cuernavaca, Morelos, CP, 62210, Mexico
| | - Thomas Müller
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Andrew Woehler
- BIMSB Light Microscopy Platform, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Carmen Birchmeier
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Enrique Merino
- Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAM, Av. Universidad 2001, Cuernavaca, Morelos, CP, 62210, Mexico
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Uwe Ohler
- Computational Regulatory Genomics, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Esteban O Mazzoni
- Department of Biology, New York University, New York, NY, 10003-6688, USA
| | - Matthias Selbach
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Altuna Akalin
- BIMSB Bioinformatics Platform, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Marina Chekulaeva
- Non-coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany.
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30
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Bernadzki KM, Gawor M, Pęziński M, Mazurek P, Niewiadomski P, Rędowicz MJ, Prószyński TJ. Liprin-α-1 is a novel component of the murine neuromuscular junction and is involved in the organization of the postsynaptic machinery. Sci Rep 2017; 7:9116. [PMID: 28831123 PMCID: PMC5567263 DOI: 10.1038/s41598-017-09590-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/25/2017] [Indexed: 01/26/2023] Open
Abstract
Neuromuscular junctions (NMJs) are specialized synapses that connect motor neurons to skeletal muscle fibers and orchestrate proper signal transmission from the nervous system to muscles. The efficient formation and maintenance of the postsynaptic machinery that contains acetylcholine receptors (AChR) are indispensable for proper NMJ function. Abnormalities in the organization of synaptic components often cause severe neuromuscular disorders, such as muscular dystrophy. The dystrophin-associated glycoprotein complex (DGC) was shown to play an important role in NMJ development. We recently identified liprin-α-1 as a novel binding partner for one of the cytoplasmic DGC components, α-dystrobrevin-1. In the present study, we performed a detailed analysis of localization and function of liprin-α-1 at the murine NMJ. We showed that liprin-α-1 localizes to both pre- and postsynaptic compartments at the NMJ, and its synaptic enrichment depends on the presence of the nerve. Using cultured muscle cells, we found that liprin-α-1 plays an important role in AChR clustering and the organization of cortical microtubules. Our studies provide novel insights into the function of liprin-α-1 at vertebrate neuromuscular synapses.
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Affiliation(s)
- Krzysztof M Bernadzki
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Marta Gawor
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Marcin Pęziński
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Paula Mazurek
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Paweł Niewiadomski
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Maria J Rędowicz
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Tomasz J Prószyński
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland.
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31
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Torres VI, Inestrosa NC. Vertebrate Presynaptic Active Zone Assembly: a Role Accomplished by Diverse Molecular and Cellular Mechanisms. Mol Neurobiol 2017; 55:4513-4528. [PMID: 28685386 DOI: 10.1007/s12035-017-0661-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/14/2017] [Indexed: 01/22/2023]
Abstract
Among all the biological systems in vertebrates, the central nervous system (CNS) is the most complex, and its function depends on specialized contacts among neurons called synapses. The assembly and organization of synapses must be exquisitely regulated for a normal brain function and network activity. There has been a tremendous effort in recent decades to understand the molecular and cellular mechanisms participating in the formation of new synapses and their organization, maintenance, and regulation. At the vertebrate presynapses, proteins such as Piccolo, Bassoon, RIM, RIM-BPs, CAST/ELKS, liprin-α, and Munc13 are constant residents and participate in multiple and dynamic interactions with other regulatory proteins, which define network activity and normal brain function. Here, we review the function of these active zone (AZ) proteins and diverse factors involved in AZ assembly and maintenance, with an emphasis on axonal trafficking of precursor vesicles, protein homo- and hetero-oligomeric interactions as a mechanism of AZ trapping and stabilization, and the role of F-actin in presynaptic assembly and its modulation by Wnt signaling.
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Affiliation(s)
- Viviana I Torres
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Center for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia. .,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile.
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32
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Kolodkin AL, Hiesinger PR. Wiring visual systems: common and divergent mechanisms and principles. Curr Opin Neurobiol 2017; 42:128-135. [PMID: 28064004 PMCID: PMC5316370 DOI: 10.1016/j.conb.2016.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 10/20/2022]
Abstract
The study of visual systems has a rich history, leading to the discovery and understanding of basic principles underlying the elaboration of neuronal connectivity. Recent work in model organisms such as fly, fish and mouse has yielded a wealth of new insights into visual system wiring. Here, we consider how axonal and dendritic patterning in columns and laminae influence synaptic partner selection in these model organisms. We highlight similarities and differences among disparate visual systems with the goal of identifying common and divergent principles for visual system wiring.
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Affiliation(s)
- Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience and Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - P Robin Hiesinger
- Division of Neurobiology of the Institute for Biology, Free University Berlin, Germany.
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33
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m6A modulates neuronal functions and sex determination in Drosophila. Nature 2016; 540:242-247. [DOI: 10.1038/nature20568] [Citation(s) in RCA: 324] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 10/21/2016] [Indexed: 12/28/2022]
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34
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Mana G, Clapero F, Panieri E, Panero V, Böttcher RT, Tseng HY, Saltarin F, Astanina E, Wolanska KI, Morgan MR, Humphries MJ, Santoro MM, Serini G, Valdembri D. PPFIA1 drives active α5β1 integrin recycling and controls fibronectin fibrillogenesis and vascular morphogenesis. Nat Commun 2016; 7:13546. [PMID: 27876801 PMCID: PMC5122980 DOI: 10.1038/ncomms13546] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 10/13/2016] [Indexed: 01/16/2023] Open
Abstract
Basolateral polymerization of cellular fibronectin (FN) into a meshwork drives endothelial cell (EC) polarity and vascular remodelling. However, mechanisms coordinating α5β1 integrin-mediated extracellular FN endocytosis and exocytosis of newly synthesized FN remain elusive. Here we show that, on Rab21-elicited internalization, FN-bound/active α5β1 is recycled to the EC surface. We identify a pathway, comprising the regulators of post-Golgi carrier formation PI4KB and AP-1A, the small GTPase Rab11B, the surface tyrosine phosphatase receptor PTPRF and its adaptor PPFIA1, which we propose acts as a funnel combining FN secretion and recycling of active α5β1 integrin from the trans-Golgi network (TGN) to the EC surface, thus allowing FN fibrillogenesis. In this framework, PPFIA1 interacts with active α5β1 integrin and localizes close to EC adhesions where post-Golgi carriers are targeted. We show that PPFIA1 is required for FN polymerization-dependent vascular morphogenesis, both in vitro and in the developing zebrafish embryo.
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Affiliation(s)
- Giulia Mana
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
| | - Fabiana Clapero
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
| | - Emiliano Panieri
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Valentina Panero
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Ralph T. Böttcher
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Hui-Yuan Tseng
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Federico Saltarin
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
| | - Elena Astanina
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Vascular Oncology, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
| | - Katarzyna I. Wolanska
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Mark R. Morgan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Martin J. Humphries
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine & Health, University of Manchester, Manchester M13 9PT, UK
| | - Massimo M. Santoro
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
- Laboratory of Endothelial Molecular Biology, Vesalius Research Center, VIB, Leuven B-3000, Belgium
| | - Guido Serini
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
| | - Donatella Valdembri
- Department of Oncology, University of Torino School of Medicine, Candiolo, Torino 10060, Italy
- Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute—Fondazione del Piemonte per l'Oncologia (FPO), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Candiolo, Torino 10060, Italy
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35
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Budayeva HG, Cristea IM. Human Sirtuin 2 Localization, Transient Interactions, and Impact on the Proteome Point to Its Role in Intracellular Trafficking. Mol Cell Proteomics 2016; 15:3107-3125. [PMID: 27503897 DOI: 10.1074/mcp.m116.061333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Indexed: 11/06/2022] Open
Abstract
Human sirtuin 2 (SIRT2) is an NAD+-dependent deacetylase that primarily functions in the cytoplasm, where it can regulate α-tubulin acetylation levels. SIRT2 is linked to cancer progression, neurodegeneration, and infection with bacteria or viruses. However, the current knowledge about its interactions and the means through which it exerts its functions has remained limited. Here, we aimed to gain a better understanding of its cellular functions by characterizing SIRT2 subcellular localization, the identity and relative stability of its protein interactions, and its impact on the proteome of primary human fibroblasts. To assess the relative stability of SIRT2 interactions, we used immunoaffinity purification in conjunction with both label-free and metabolic labeling quantitative mass spectrometry. In addition to the expected associations with cytoskeleton proteins, including its known substrate TUBA1A, our results reveal that SIRT2 specifically interacts with proteins functioning in membrane trafficking, secretory processes, and transcriptional regulation. By quantifying their relative stability, we found most interactions to be transient, indicating a dynamic SIRT2 environment. We discover that SIRT2 localizes to the ER-Golgi intermediate compartment (ERGIC), and that this recruitment requires an intact ER-Golgi trafficking pathway. Further expanding these findings, we used microscopy and interaction assays to establish the interaction and coregulation of SIRT2 with liprin-β1 scaffolding protein (PPFiBP1), a protein with roles in focal adhesions disassembly. As SIRT2 functions may be accomplished via interactions, enzymatic activity, and transcriptional regulation, we next assessed the impact of SIRT2 levels on the cellular proteome. SIRT2 knockdown led to changes in the levels of proteins functioning in membrane trafficking, including some of its interaction partners. Altogether, our study expands the knowledge of SIRT2 cytoplasmic functions to define a previously unrecognized involvement in intracellular trafficking pathways, which may contribute to its roles in cellular homeostasis and human diseases.
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Affiliation(s)
- Hanna G Budayeva
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Ileana M Cristea
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
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36
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Pinto MJ, Almeida RD. Puzzling out presynaptic differentiation. J Neurochem 2016; 139:921-942. [PMID: 27315450 DOI: 10.1111/jnc.13702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/27/2016] [Accepted: 06/10/2016] [Indexed: 12/24/2022]
Abstract
Proper brain function in the nervous system relies on the accurate establishment of synaptic contacts during development. Countless synapses populate the adult brain in an orderly fashion. In each synapse, a presynaptic terminal loaded with neurotransmitters-containing synaptic vesicles is perfectly aligned to an array of receptors in the postsynaptic membrane. Presynaptic differentiation, which encompasses the events underlying assembly of new presynaptic units, has seen notable advances in recent years. It is now consensual that as a growing axon encounters the receptive dendrites of its partner, presynaptic assembly will be triggered and specified by multiple postsynaptically-derived factors including soluble molecules and cell adhesion complexes. Presynaptic material that reaches these distant sites by axonal transport in the form of pre-assembled packets will be retained and clustered, ultimately giving rise to a presynaptic bouton. This review focuses on the cellular and molecular aspects of presynaptic differentiation in the central nervous system, with a particular emphasis on the identity of the instructive factors and the intracellular processes used by neuronal cells to assemble functional presynaptic terminals. We provide a detailed description of the mechanisms leading to the formation of new presynaptic terminals. In brief, soma-derived packets of pre-assembled material are trafficked to distant axonal sites. Synaptogenic factors from dendritic or glial provenance activate downstream intra-axonal mediators to trigger clustering of passing material and their correct organization into a new presynaptic bouton. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Maria J Pinto
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ramiro D Almeida
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,School of Allied Health Technologies, Polytechnic Institute of Oporto, Vila Nova de Gaia, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
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37
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Kulkarni A, Ertekin D, Lee CH, Hummel T. Birth order dependent growth cone segregation determines synaptic layer identity in the Drosophila visual system. eLife 2016; 5:e13715. [PMID: 26987017 PMCID: PMC4846375 DOI: 10.7554/elife.13715] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/16/2016] [Indexed: 12/13/2022] Open
Abstract
The precise recognition of appropriate synaptic partner neurons is a critical step during neural circuit assembly. However, little is known about the developmental context in which recognition specificity is important to establish synaptic contacts. We show that in the Drosophila visual system, sequential segregation of photoreceptor afferents, reflecting their birth order, lead to differential positioning of their growth cones in the early target region. By combining loss- and gain-of-function analyses we demonstrate that relative differences in the expression of the transcription factor Sequoia regulate R cell growth cone segregation. This initial growth cone positioning is consolidated via cell-adhesion molecule Capricious in R8 axons. Further, we show that the initial growth cone positioning determines synaptic layer selection through proximity-based axon-target interactions. Taken together, we demonstrate that birth order dependent pre-patterning of afferent growth cones is an essential pre-requisite for the identification of synaptic partner neurons during visual map formation in Drosophila. DOI:http://dx.doi.org/10.7554/eLife.13715.001 A nervous system requires a precise network of connections between cells called neurons to work properly. Within the brain, the fiber-like connections between pairs of neurons are not running crisscross like a pile of spaghetti. Instead, connected partner neurons are organized into distinct layers and columns. Many questions remain about how these partner neurons find each other and how the layers of fiber-like connections form. To answer these questions, scientists often study the part of the fruit fly nervous system that controls the insect’s vision. This brain-like structure is simple and can be easily manipulated with genetic engineering. Fruit fly studies have helped identify some molecules that play a role in helping partner cells find one another and connect. These studies have also shown that the timing of brain cell development appears to play a role. But the role that layer formation plays in the process is still a mystery. Now, Kulkarni et al. show that the birthdate of neurons in the fruit fly visual system helps organize them into layers. These neurons are generated early in the development of the fly. Shortly after birth, a molecular clock under the control of a protein called Sequoia starts within each newly generated neuron. The Sequoia protein is a transcription factor and controls the activity of many genes, and the molecular clock provides the growing neuron fibers with information about where and when to look for its partner neurons. By manipulating the amount and time that Sequoia is produced in the fly visual system, Kulkarni et al. show that this clock helps arrange the growing cells into layers. Cells with similar birthdates connect and are arranged into layers. How much and when Sequoia is produced dictates where each new layer begins. The next steps for the research will be to learn more about how the clock works and identify any intermediaries between the clock and cell growth patterns. DOI:http://dx.doi.org/10.7554/eLife.13715.002
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Affiliation(s)
| | - Deniz Ertekin
- Department of Neurobiology, University of Vienna, Vienna, Austria
| | - Chi-Hon Lee
- Section on Neuronal Connectivity, Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, United States
| | - Thomas Hummel
- Department of Neurobiology, University of Vienna, Vienna, Austria
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38
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Brenig J, de Boor S, Knyphausen P, Kuhlmann N, Wroblowski S, Baldus L, Scislowski L, Artz O, Trauschies P, Baumann U, Neundorf I, Lammers M. Structural and Biochemical Basis for the Inhibitory Effect of Liprin-α3 on Mouse Diaphanous 1 (mDia1) Function. J Biol Chem 2015; 290:14314-27. [PMID: 25911102 DOI: 10.1074/jbc.m114.621946] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Indexed: 11/06/2022] Open
Abstract
Diaphanous-related formins are eukaryotic actin nucleation factors regulated by an autoinhibitory interaction between the N-terminal RhoGTPase-binding domain (mDiaN) and the C-terminal Diaphanous-autoregulatory domain (DAD). Although the activation of formins by Rho proteins is well characterized, its inactivation is only marginally understood. Recently, liprin-α3 was shown to interact with mDia1. Overexpression of liprin-α3 resulted in a reduction of the cellular actin filament content. The molecular mechanisms of how liprin-α3 exerts this effect and counteracts mDia1 activation by RhoA are unknown. Here, we functionally and structurally define a minimal liprin-α3 core region, sufficient to recapitulate the liprin-α3 determined mDia1-respective cellular functions. We show that liprin-α3 alters the interaction kinetics and thermodynamics of mDiaN with RhoA·GTP and DAD. RhoA displaces liprin-α3 allosterically, whereas DAD competes with liprin-α3 for a highly overlapping binding site on mDiaN. Liprin-α3 regulates actin polymerization by lowering the regulatory potency of RhoA and DAD on mDiaN. We present a model of a mechanistically unexplored and new aspect of mDiaN regulation by liprin-α3.
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Affiliation(s)
- Julian Brenig
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Susanne de Boor
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Philipp Knyphausen
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Nora Kuhlmann
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Sarah Wroblowski
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Linda Baldus
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Lukas Scislowski
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Oliver Artz
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Philip Trauschies
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
| | - Ulrich Baumann
- the Institute for Biochemistry, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany
| | - Ines Neundorf
- the Institute for Biochemistry, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany
| | - Michael Lammers
- From the Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), Joseph-Stelzmann-Strasse 26, University of Cologne, 50931 Cologne, Germany and
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39
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Astro V, de Curtis I. Plasma membrane-associated platforms: Dynamic scaffolds that organize membrane-associated events. Sci Signal 2015; 8:re1. [DOI: 10.1126/scisignal.aaa3312] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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40
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Zong W, Liu S, Wang X, Zhang J, Zhang T, Liu Z, Wang D, Zhang A, Zhu M, Gao J. Trio gene is required for mouse learning ability. Brain Res 2015; 1608:82-90. [PMID: 25727174 DOI: 10.1016/j.brainres.2015.02.040] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 02/03/2015] [Accepted: 02/15/2015] [Indexed: 01/08/2023]
Abstract
Trio is a guanine nucleotide exchange factor with multiple guanine nucleotide exchange factor domains. Trio regulates cytoskeleton dynamics and actin remodeling and is involved in cell migration and axonal guidance in neuronal development. The null allele of the Trio gene led to embryonic lethality, and Trio null embryos displayed aberrant organization in several regions of the brain at E18.5, including hippocampus. Nestin-Trio-/- mice, in which the Trio gene was deleted specifically in the neuronal system by the Nestin-Cre system, displayed severe phenotypes, including low survival rate, ataxia and multiple developmental defects of the cerebellum. All Nestin-Trio-/- mice died before reaching adulthood, which hinders research on Trio gene function in adult mice. Thus, we generated EMX1-Trio-/- mice by crossing Trio-floxed mice with EMX1-Cre mice in which Cre is expressed in the brain cortex and hippocampus. EMX1-Trio-/- mice can survive to adulthood. Trio gene deletion results in smaller brains, an abnormal hippocampus and disordered granule cells in the dentate gyrus (DG) and cornu ammonis (CA). Behavior tests showed that Trio deletion interfered with the hippocampal-dependent spatial learning in the mice, suggesting that Trio plays critical roles in the learning ability of adult mice. We conclude that the Trio gene regulates the neuronal development of the hippocampus and that it affects the intelligence of adult mice.
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Affiliation(s)
- Wen Zong
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Shuoyang Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Xiaotong Wang
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jian Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Tingting Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Ziyi Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Dongdong Wang
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Aizhen Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Minsheng Zhu
- Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing210061, China.
| | - Jiangang Gao
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China.
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41
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Sakamoto S, Narumiya S, Ishizaki T. A new role of multi scaffold protein Liprin-α: Liprin-α suppresses Rho-mDia mediated stress fiber formation. BIOARCHITECTURE 2014; 2:43-49. [PMID: 22754629 PMCID: PMC3383721 DOI: 10.4161/bioa.20442] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Regulation of the actin cytoskeleton is crucial for cell morphology and migration. One of the key molecules that regulates actin remodeling is the small GTPase Rho. Rho shuttles between the inactive GDP-bound form and the active GTP-bound form, and works as a molecular switch in actin remodeling in response to both extra- and intra-cellular stimuli. Mammalian homolog of Diaphanous (mDia) is one of the Rho effectors and produces unbranched actin filaments. While Rho GTPases activate mDia, the mechanisms of how the activity of mDia is downregulated in cells remains largely unknown. In our recent paper, we identified Liprin-α as an mDia interacting protein and found that Liprin-α negatively regulates the activity of mDia in the cell by displacing it from the plasma membrane through binding to the DID-DD region of mDia. Here, we review these findings and discuss how Liprin-α regulates the Rho-mDia pathway and how the mDia-Liprin-α complex functions in vivo.
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Affiliation(s)
- Satoko Sakamoto
- Department of Pharmacology; Kyoto University Graduate School of Medicine; Kyoto, Japan
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42
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Chua JJE. Macromolecular complexes at active zones: integrated nano-machineries for neurotransmitter release. Cell Mol Life Sci 2014; 71:3903-16. [PMID: 24912984 PMCID: PMC11113288 DOI: 10.1007/s00018-014-1657-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 02/06/2023]
Abstract
The release of neurotransmitters from synaptic vesicles exocytosing at presynaptic nerve terminals is a critical event in the initiation of synaptic transmission. This event occurs at specialized sites known as active zones. The task of faithfully executing various steps in the process is undertaken by careful orchestration of overlapping sets of molecular nano-machineries upon a core macromolecular scaffold situated at active zones. However, their composition remains incompletely elucidated. This review provides an overview of the role of the active zone in mediating neurotransmitter release and summarizes the recent progress using neuroproteomic approaches to decipher their composition. Key proteins of these nano-machineries are highlighted.
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Affiliation(s)
- John Jia En Chua
- Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany,
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43
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A comparison of midline and tracheal gene regulation during Drosophila development. PLoS One 2014; 9:e85518. [PMID: 24465586 PMCID: PMC3896416 DOI: 10.1371/journal.pone.0085518] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 11/28/2013] [Indexed: 11/19/2022] Open
Abstract
Within the Drosophila embryo, two related bHLH-PAS proteins, Single-minded and Trachealess, control development of the central nervous system midline and the trachea, respectively. These two proteins are bHLH-PAS transcription factors and independently form heterodimers with another bHLH-PAS protein, Tango. During early embryogenesis, expression of Single-minded is restricted to the midline and Trachealess to the trachea and salivary glands, whereas Tango is ubiquitously expressed. Both Single-minded/Tango and Trachealess/Tango heterodimers bind to the same DNA sequence, called the CNS midline element (CME) within cis-regulatory sequences of downstream target genes. While Single-minded/Tango and Trachealess/Tango activate some of the same genes in their respective tissues during embryogenesis, they also activate a number of different genes restricted to only certain tissues. The goal of this research is to understand how these two related heterodimers bind different enhancers to activate different genes, thereby regulating the development of functionally diverse tissues. Existing data indicates that Single-minded and Trachealess may bind to different co-factors restricted to various tissues, causing them to interact with the CME only within certain sequence contexts. This would lead to the activation of different target genes in different cell types. To understand how the context surrounding the CME is recognized by different bHLH-PAS heterodimers and their co-factors, we identified and analyzed novel enhancers that drive midline and/or tracheal expression and compared them to previously characterized enhancers. In addition, we tested expression of synthetic reporter genes containing the CME flanked by different sequences. Taken together, these experiments identify elements overrepresented within midline and tracheal enhancers and suggest that sequences immediately surrounding a CME help dictate whether a gene is expressed in the midline or trachea.
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Kowalski JR, Dube H, Touroutine D, Rush KM, Goodwin PR, Carozza M, Didier Z, Francis MM, Juo P. The Anaphase-Promoting Complex (APC) ubiquitin ligase regulates GABA transmission at the C. elegans neuromuscular junction. Mol Cell Neurosci 2014; 58:62-75. [PMID: 24321454 PMCID: PMC4036811 DOI: 10.1016/j.mcn.2013.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 11/23/2013] [Accepted: 12/02/2013] [Indexed: 01/05/2023] Open
Abstract
Regulation of both excitatory and inhibitory synaptic transmission is critical for proper nervous system function. Aberrant synaptic signaling, including altered excitatory to inhibitory balance, is observed in numerous neurological diseases. The ubiquitin enzyme system controls the abundance of many synaptic proteins and thus plays a key role in regulating synaptic transmission. The Anaphase-Promoting Complex (APC) is a multi-subunit ubiquitin ligase that was originally discovered as a key regulator of protein turnover during the cell cycle. More recently, the APC has been shown to function in postmitotic neurons, where it regulates diverse processes such as synapse development and synaptic transmission at glutamatergic synapses. Here we report that the APC regulates synaptic GABA signaling by acting in motor neurons to control the balance of excitatory (acetylcholine) to inhibitory (GABA) transmission at the Caenorhabditis elegans neuromuscular junction (NMJ). Loss-of-function mutants in multiple APC subunits have increased muscle excitation at the NMJ; this phenotype is rescued by expression of the missing subunit in GABA neurons. Quantitative imaging and electrophysiological analyses indicate that APC mutants have decreased GABA release but normal cholinergic transmission. Consistent with this, APC mutants exhibit convulsions in a seizure assay sensitive to reductions in GABA signaling. Previous studies in other systems showed that the APC can negatively regulate the levels of the active zone protein SYD-2 Liprin-α. Similarly, we found that SYD-2 accumulates in APC mutants at GABAergic presynaptic sites. Finally, we found that the APC subunit EMB-27 CDC16 can localize to presynapses in GABA neurons. Together, our data suggest a model in which the APC acts at GABAergic presynapses to promote GABA release and inhibit muscle excitation. These findings are the first evidence that the APC regulates transmission at inhibitory synapses and have implications for understanding nervous system pathologies, such as epilepsy, that are characterized by misregulated GABA signaling.
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Affiliation(s)
- Jennifer R Kowalski
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Hitesh Dube
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Denis Touroutine
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Kristen M Rush
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Patricia R Goodwin
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Marc Carozza
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Zachary Didier
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Peter Juo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
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Retrograde BMP signaling at the synapse: a permissive signal for synapse maturation and activity-dependent plasticity. J Neurosci 2013; 33:17937-50. [PMID: 24198381 DOI: 10.1523/jneurosci.6075-11.2013] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
At the Drosophila neuromuscular junction (NMJ), the loss of retrograde, trans-synaptic BMP signaling causes motoneuron terminals to have fewer synaptic boutons, whereas increased neuronal activity results in a larger synapse with more boutons. Here, we show that an early and transient BMP signal is necessary and sufficient for NMJ growth as well as for activity-dependent synaptic plasticity. This early critical period was revealed by the temporally controlled suppression of Mad, the SMAD1 transcriptional regulator. Similar results were found by genetic rescue tests involving the BMP4/5/6 ligand Glass bottom boat (Gbb) in muscle, and alternatively the type II BMP receptor Wishful Thinking (Wit) in the motoneuron. These observations support a model where the muscle signals back to the innervating motoneuron's nucleus to activate presynaptic programs necessary for synaptic growth and activity-dependent plasticity. Molecular genetic gain- and loss-of-function studies show that genes involved in NMJ growth and plasticity, including the adenylyl cyclase Rutabaga, the Ig-CAM Fasciclin II, the transcription factor AP-1 (Fos/Jun), and the adhesion protein Neurexin, all depend critically on the canonical BMP pathway for their effects. By contrast, elevated expression of Lar, a receptor protein tyrosine phosphatase found to be necessary for activity-dependent plasticity, rescued the phenotypes associated with the loss of Mad signaling. We also find that synaptic structure and function develop using genetically separable, BMP-dependent mechanisms. Although synaptic growth depended on Lar and the early, transient BMP signal, the maturation of neurotransmitter release was independent of Lar and required later, ongoing BMP signaling.
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Chia PH, Li P, Shen K. Cell biology in neuroscience: cellular and molecular mechanisms underlying presynapse formation. ACTA ACUST UNITED AC 2013; 203:11-22. [PMID: 24127213 PMCID: PMC3798257 DOI: 10.1083/jcb.201307020] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Synapse formation is a highly regulated process that requires the coordination of many cell biological events. Decades of research have identified a long list of molecular components involved in assembling a functioning synapse. Yet how the various steps, from transporting synaptic components to adhering synaptic partners and assembling the synaptic structure, are regulated and precisely executed during development and maintenance is still unclear. With the improvement of imaging and molecular tools, recent work in vertebrate and invertebrate systems has provided important insight into various aspects of presynaptic development, maintenance, and trans-synaptic signals, thereby increasing our understanding of how extrinsic organizers and intracellular mechanisms contribute to presynapse formation.
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Affiliation(s)
- Poh Hui Chia
- Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
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47
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LAR-RPTPs: synaptic adhesion molecules that shape synapse development. Trends Cell Biol 2013; 23:465-75. [DOI: 10.1016/j.tcb.2013.07.004] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/07/2013] [Accepted: 07/08/2013] [Indexed: 12/21/2022]
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48
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Spangler SA, Schmitz SK, Kevenaar JT, de Graaff E, de Wit H, Demmers J, Toonen RF, Hoogenraad CC. Liprin-α2 promotes the presynaptic recruitment and turnover of RIM1/CASK to facilitate synaptic transmission. ACTA ACUST UNITED AC 2013; 201:915-28. [PMID: 23751498 PMCID: PMC3678157 DOI: 10.1083/jcb.201301011] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Liprin-α2 is required for the presynaptic recruitment and turnover of RIM1 and CASK, components of the release machinery, and facilitates synaptic output by regulating synaptic vesicle pool size. The presynaptic active zone mediates synaptic vesicle exocytosis, and modulation of its molecular composition is important for many types of synaptic plasticity. Here, we identify synaptic scaffold protein liprin-α2 as a key organizer in this process. We show that liprin-α2 levels were regulated by synaptic activity and the ubiquitin–proteasome system. Furthermore, liprin-α2 organized presynaptic ultrastructure and controlled synaptic output by regulating synaptic vesicle pool size. The presence of liprin-α2 at presynaptic sites did not depend on other active zone scaffolding proteins but was critical for recruitment of several components of the release machinery, including RIM1 and CASK. Fluorescence recovery after photobleaching showed that depletion of liprin-α2 resulted in reduced turnover of RIM1 and CASK at presynaptic terminals, suggesting that liprin-α2 promotes dynamic scaffolding for molecular complexes that facilitate synaptic vesicle release. Therefore, liprin-α2 plays an important role in maintaining active zone dynamics to modulate synaptic efficacy in response to changes in network activity.
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Affiliation(s)
- Samantha A Spangler
- Department of Neuroscience, Erasmus Medical Center, 3015GE Rotterdam, Netherlands
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49
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Protein tyrosine phosphatases PTPδ, PTPσ, and LAR: presynaptic hubs for synapse organization. Trends Neurosci 2013; 36:522-34. [PMID: 23835198 DOI: 10.1016/j.tins.2013.06.002] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/03/2013] [Accepted: 06/11/2013] [Indexed: 02/04/2023]
Abstract
Synapse development requires differentiation of presynaptic neurotransmitter release sites and postsynaptic receptive apparatus coordinated by synapse organizing proteins. In addition to the well-characterized neurexins, recent studies identified presynaptic type IIa receptor-type protein tyrosine phosphatases (RPTPs) as mediators of presynaptic differentiation and triggers of postsynaptic differentiation, thus extending the roles of RPTPs from axon outgrowth and guidance. Similarly to neurexins, RPTPs exist in multiple isoforms generated by alternative splicing that interact in a splice-selective code with diverse postsynaptic partners. The parallel RPTP and neurexin hub design facilitates synapse self-assembly through cooperation, pairs presynaptic similarity with postsynaptic diversity, and balances excitation with inhibition. Upon mutation of individual genes in neuropsychiatric disorders, imbalance of this synaptic organizing network may contribute to impaired cognitive function.
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50
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Abstract
Genetic analyses in both worm and fly have identified the RhoGAP-like protein Syd-1 as a key positive regulator of presynaptic assembly. In worm, loss of syd-1 can be fully rescued by overexpressing wild-type Liprin-α, suggesting that the primary function of Syd-1 in this process is to recruit Liprin-α. We show that loss of syd-1 from Drosophila R7 photoreceptors causes two morphological defects that occur at distinct developmental time points. First, syd-1 mutant R7 axons often fail to form terminal boutons in their normal M6 target layer. Later, those mutant axons that do contact M6 often project thin extensions beyond it. We find that the earlier defect coincides with a failure to localize synaptic vesicles, suggesting that it reflects a failure in presynaptic assembly. We then analyze the relationship between syd-1 and Liprin-α in R7s. We find that loss of Liprin-α causes a stronger early R7 defect and provide a possible explanation for this disparity: we show that Liprin-α promotes Kinesin-3/Unc-104/Imac-mediated axon transport independently of Syd-1 and that Kinesin-3/Unc-104/Imac is required for normal R7 bouton formation. Unlike loss of syd-1, loss of Liprin-α does not cause late R7 extensions. We show that overexpressing Liprin-α partly rescues the early but not the late syd-1 mutant R7 defect. We therefore conclude that the two defects are caused by distinct molecular mechanisms. We find that Trio overexpression rescues both syd-1 defects and that trio and syd-1 have similar loss- and gain-of-function phenotypes, suggesting that the primary function of Syd-1 in R7s may be to promote Trio activity.
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