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Han TH, Vicidomini R, Ramos CI, Mayer M, Serpe M. Neto proteins differentially modulate the gating properties of Drosophila NMJ glutamate receptors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590603. [PMID: 38903091 PMCID: PMC11188076 DOI: 10.1101/2024.04.22.590603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The formation of functional synapses requires co-assembly of ion channels with their accessory proteins which controls where, when, and how neurotransmitter receptors function. The auxiliary protein Neto modulates the function of kainate-type glutamate receptors in vertebrates as well as at the Drosophila neuromuscular junction (NMJ), a glutamatergic synapse widely used for genetic studies on synapse development. We previously reported that Neto is essential for the synaptic recruitment and function of glutamate receptors. Here, using outside-out patch-clamp recordings and fast ligand application, we examine for the first time the biophysical properties of recombinant Drosophila NMJ receptors expressed in HEK293T cells and compare them with native receptor complexes of genetically controlled composition. The two Neto isoforms, Neto-α and Neto-β, differentially modulate the gating properties of NMJ receptors. Surprisingly, we found that deactivation is extremely fast and that the decay of synaptic currents resembles the rate of iGluR desensitization. The functional analyses of recombinant iGluRs that we report here should greatly facilitate the interpretation of compound in vivo phenotypes of mutant animals.
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Affiliation(s)
- Tae Hee Han
- Section on Cellular Communication, Eunice Kennedy Shiver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA
| | - Rosario Vicidomini
- Section on Cellular Communication, Eunice Kennedy Shiver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA
| | - Cathy Isaura Ramos
- Section on Cellular Communication, Eunice Kennedy Shiver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA
- current address: The Institute of Functional Genomics of Lyon, 69007 Lyon, France
| | - Mark Mayer
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
| | - Mihaela Serpe
- Section on Cellular Communication, Eunice Kennedy Shiver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA
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2
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Smith IR, Hendricks EL, Latcheva NK, Marenda DR, Liebl FLW. The CHD Protein Kismet Restricts the Synaptic Localization of Cell Adhesion Molecules at the Drosophila Neuromuscular Junction. Int J Mol Sci 2024; 25:3074. [PMID: 38474321 PMCID: PMC10931923 DOI: 10.3390/ijms25053074] [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: 01/21/2024] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
The appropriate expression and localization of cell surface cell adhesion molecules must be tightly regulated for optimal synaptic growth and function. How neuronal plasma membrane proteins, including cell adhesion molecules, cycle between early endosomes and the plasma membrane is poorly understood. Here we show that the Drosophila homolog of the chromatin remodeling enzymes CHD7 and CHD8, Kismet, represses the synaptic levels of several cell adhesion molecules. Neuroligins 1 and 3 and the integrins αPS2 and βPS are increased at kismet mutant synapses but Kismet only directly regulates transcription of neuroligin 2. Kismet may therefore regulate synaptic CAMs indirectly by activating transcription of gene products that promote intracellular vesicle trafficking including endophilin B (endoB) and/or rab11. Knock down of EndoB in all tissues or neurons increases synaptic FasII while knock down of EndoB in kis mutants does not produce an additive increase in FasII. In contrast, neuronal expression of Rab11, which is deficient in kis mutants, leads to a further increase in synaptic FasII in kis mutants. These data support the hypothesis that Kis influences the synaptic localization of FasII by promoting intracellular vesicle trafficking through the early endosome.
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Affiliation(s)
- Ireland R. Smith
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
| | - Emily L. Hendricks
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
| | - Nina K. Latcheva
- Department of Biology, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA (D.R.M.)
- Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19104, USA
- Neurogenetics Program, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Daniel R. Marenda
- Department of Biology, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA (D.R.M.)
- Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19104, USA
- Division of Biological Infrastructure, National Science Foundation, Alexandria, VA 22314, USA
| | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62025, USA
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3
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Shpak M, Ghanavi HR, Lange JD, Pool JE, Stensmyr MC. Genomes from historical Drosophila melanogaster specimens illuminate adaptive and demographic changes across more than 200 years of evolution. PLoS Biol 2023; 21:e3002333. [PMID: 37824452 PMCID: PMC10569592 DOI: 10.1371/journal.pbio.3002333] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 09/11/2023] [Indexed: 10/14/2023] Open
Abstract
The ability to perform genomic sequencing on long-dead organisms is opening new frontiers in evolutionary research. These opportunities are especially notable in the case of museum collections, from which countless documented specimens may now be suitable for genomic analysis-if data of sufficient quality can be obtained. Here, we report 25 newly sequenced genomes from museum specimens of the model organism Drosophila melanogaster, including the oldest extant specimens of this species. By comparing historical samples ranging from the early 1800s to 1933 against modern-day genomes, we document evolution across thousands of generations, including time periods that encompass the species' initial occupation of northern Europe and an era of rapidly increasing human activity. We also find that the Lund, Sweden population underwent local genetic differentiation during the early 1800s to 1933 interval (potentially due to drift in a small population) but then became more similar to other European populations thereafter (potentially due to increased migration). Within each century-scale time period, our temporal sampling allows us to document compelling candidates for recent natural selection. In some cases, we gain insights regarding previously implicated selection candidates, such as ChKov1, for which our inferred timing of selection favors the hypothesis of antiviral resistance over insecticide resistance. Other candidates are novel, such as the circadian-related gene Ahcy, which yields a selection signal that rivals that of the DDT resistance gene Cyp6g1. These insights deepen our understanding of recent evolution in a model system, and highlight the potential of future museomic studies.
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Affiliation(s)
- Max Shpak
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | | | - Jeremy D. Lange
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - John E. Pool
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Marcus C. Stensmyr
- Department of Biology, Lund University, Lund, Scania, Sweden
- Max Planck Center on Next Generation Insect Chemical Ecology, Lund, Sweden
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4
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Sahota VK, Stone A, Woodling NS, Spiers JG, Steinert JR, Partridge L, Augustin H. Plum modulates Myoglianin and regulates synaptic function in D. melanogaster. Open Biol 2023; 13:230171. [PMID: 37699519 PMCID: PMC10497343 DOI: 10.1098/rsob.230171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023] Open
Abstract
Alterations in the neuromuscular system underlie several neuromuscular diseases and play critical roles in the development of sarcopenia, the age-related loss of muscle mass and function. Mammalian Myostatin (MST) and GDF11, members of the TGF-β superfamily of growth factors, are powerful regulators of muscle size in both model organisms and humans. Myoglianin (MYO), the Drosophila homologue of MST and GDF11, is a strong inhibitor of synaptic function and structure at the neuromuscular junction in flies. Here, we identified Plum, a transmembrane cell surface protein, as a modulator of MYO function in the larval neuromuscular system. Reduction of Plum in the larval body-wall muscles abolishes the previously demonstrated positive effect of attenuated MYO signalling on both muscle size and neuromuscular junction structure and function. In addition, downregulation of Plum on its own results in decreased synaptic strength and body weight, classifying Plum as a (novel) regulator of neuromuscular function and body (muscle) size. These findings offer new insights into possible regulatory mechanisms behind ageing- and disease-related neuromuscular dysfunctions in humans and identify potential targets for therapeutic interventions.
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Affiliation(s)
- Virender K. Sahota
- Department of Biological Sciences, Centre for Biomedical Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Aelfwin Stone
- Faculty of Medicine & Health Sciences, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Nathaniel S. Woodling
- Department of Biological Sciences, Centre for Biomedical Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Jereme G. Spiers
- Faculty of Medicine & Health Sciences, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Joern R. Steinert
- Faculty of Medicine & Health Sciences, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Linda Partridge
- Institute of Healthy Ageing, and GEE, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, Cologne 50931, Germany
| | - Hrvoje Augustin
- Department of Biological Sciences, Centre for Biomedical Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- Institute of Healthy Ageing, and GEE, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, Cologne 50931, Germany
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5
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Vicidomini R, Serpe M. Local BMP signaling: A sensor for synaptic activity that balances synapse growth and function. Curr Top Dev Biol 2022; 150:211-254. [PMID: 35817503 PMCID: PMC11102767 DOI: 10.1016/bs.ctdb.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Synapse development is coordinated by intercellular communication between the pre- and postsynaptic compartments, and by neuronal activity itself. In flies as in vertebrates, neuronal activity induces input-specific changes in the synaptic strength so that the entire circuit maintains stable function in the face of many challenges, including changes in synapse number and strength. But how do neurons sense synapse activity? In several studies carried out using the Drosophila neuromuscular junction (NMJ), we demonstrated that local BMP signaling provides an exquisite sensor for synapse activity. Here we review the main features of this exquisite sensor and discuss its functioning beyond monitoring the synapse activity but rather as a key controller that operates in coordination with other BMP signaling pathways to balance synapse growth, maturation and function.
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Affiliation(s)
- Rosario Vicidomini
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shiver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Mihaela Serpe
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shiver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States.
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6
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Zhao K, Hong H, Zhao L, Huang S, Gao Y, Metwally E, Jiang Y, Sigrist SJ, Zhang YQ. Postsynaptic cAMP signalling regulates the antagonistic balance of Drosophila glutamate receptor subtypes. Development 2020; 147:226061. [PMID: 33234716 PMCID: PMC7758632 DOI: 10.1242/dev.191874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/13/2020] [Indexed: 12/19/2022]
Abstract
The balance among different subtypes of glutamate receptors (GluRs) is crucial for synaptic function and plasticity at excitatory synapses. However, the mechanisms balancing synaptic GluR subtypes remain unclear. Herein, we show that the two subtypes of GluRs (A and B) expressed at Drosophila neuromuscular junction synapses mutually antagonize each other in terms of their relative synaptic levels and affect subsynaptic localization of each other, as shown by super-resolution microscopy. Upon temperature shift-induced neuromuscular junction plasticity, GluR subtype A increased but subtype B decreased with a timecourse of hours. Inhibition of the activity of GluR subtype A led to imbalance of GluR subtypes towards more GluRIIA. To gain a better understanding of the signalling pathways underlying the balance of GluR subtypes, we performed an RNA interference screen of candidate genes and found that postsynaptic-specific knockdown of dunce, which encodes cAMP phosphodiesterase, increased levels of GluR subtype A but decreased subtype B. Furthermore, bidirectional alterations of postsynaptic cAMP signalling resulted in the same antagonistic regulation of the two GluR subtypes. Our findings thus identify a direct role of postsynaptic cAMP signalling in control of the plasticity-related balance of GluRs. Summary: The antagonistic balance of GluR subtypes, which is associated with synaptic plasticity, is regulated by cAMP signalling in postsynaptic muscles of Drosophila NMJ synapses.
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Affiliation(s)
- Kai Zhao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huilin Hong
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lu Zhao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Sheng Huang
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, 14195 Berlin, Germany
| | - Ying Gao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Elsayed Metwally
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuqiang Jiang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, 14195 Berlin, Germany.,NeuroCure, Charite, Chariteplatz 1, 10117 Berlin, Germany
| | - Yong Q Zhang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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7
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Kang HY, Kim HJ, Kim K, Oh SI, Yoon S, Kim J, Park S, Cheon Y, Her S, Lee M, Lu B, Lee S. Actin-microtubule crosslinker Pod-1 tunes PAR-1 signaling to control synaptic development and tau-mediated synaptic toxicity. Neurobiol Aging 2020; 90:93-98. [PMID: 32169355 DOI: 10.1016/j.neurobiolaging.2020.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 01/30/2020] [Accepted: 02/08/2020] [Indexed: 10/25/2022]
Abstract
Partitioning-defective 1 (PAR-1), a conserved cell polarity regulator, plays an important role in synaptic development, and its mutation affects the formation of synaptic boutons and localization of postsynaptic density protein Discs large (Dlg) at the neuromuscular junction (NMJ) in Drosophila. Drosophila PAR-1 and its human homolog, Microtubule affinity-regulating kinases (MARK), are also known to be implicated in Alzheimer's disease (AD) by controlling tau-mediated Aβ toxicity. However, the molecular mechanisms of PAR-1 function remain incompletely understood. Here we identified Pod-1, an actin-microtubule crosslinker, which functionally and physically interacts with PAR-1 in Drosophila. Pod-1 prominently co-localizes with PAR-1 in the postsynaptic region and regulates PAR-1 activity at the NMJ. Synaptic defects, including the reduction of boutons and delocalization of Dlg caused by PAR-1 overexpression, were rescued by Pod-1 knockdown. Conversely, the reduction of synaptic boutons in PAR-1 overexpressed NMJ was synergistically enhanced by the overexpression of Pod-1. Furthermore, Pod-1 increases the PAR-1 dependent S262 phosphorylation of tau, which is known to contribute to tau-mediated Aβ toxicity. In line with the change of tau phosphorylation, Pod-1 knockdown rescued tau-mediated synaptic toxicity at the NMJ. Our results suggest that Pod-1 may act as a modulator of PAR-1 in synaptic development and tau-mediated toxicity.
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Affiliation(s)
- Ha-Young Kang
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea
| | - Hyung-Jun Kim
- Dementia Research Group, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Kiyoung Kim
- Department of Medical Biotechnology, Soonchunhyang University, Asan, South Korea
| | - Seung-Il Oh
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea
| | - Sunggyu Yoon
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea; Department of Life Science, College of Natural Science, Hanyang University, Seoul, South Korea
| | - Jaekwang Kim
- Dementia Research Group, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Sangwoo Park
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea
| | - Yeongmi Cheon
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea
| | - Song Her
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea
| | - Mihye Lee
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan, South Korea.
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Seongsoo Lee
- Gwangju Center, Korea Basic Science Institute (KBSI), Gwangju, South Korea.
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8
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Bellosta P, Soldano A. Dissecting the Genetics of Autism Spectrum Disorders: A Drosophila Perspective. Front Physiol 2019; 10:987. [PMID: 31481894 PMCID: PMC6709880 DOI: 10.3389/fphys.2019.00987] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 07/18/2019] [Indexed: 01/10/2023] Open
Abstract
Autism Spectrum Disorder (ASD) is a complex group of multi-factorial developmental disorders that leads to communication and behavioral defects. Genetic alterations have been identified in around 20% of ASD patients and the use of genetic models, such as Drosophila melanogaster, has been of paramount importance in deciphering the significance of these alterations. In fact, many of the ASD associated genes, such as FMR1, Neurexin, Neuroligins and SHANK encode for proteins that have conserved functions in neurons and during synapse development, both in humans and in the fruit fly. Drosophila is a prominent model in neuroscience due to the conserved genetic networks that control neurodevelopmental processes and to the ease of manipulating its genetics. In the present review we will describe recent advances in the field of ASD with a particular focus on the characterization of genes where the use of Drosophila has been fundamental to better understand their function.
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Affiliation(s)
- Paola Bellosta
- Laboratory of Metabolism of Cell Growth and Neuronal Survival, Department of Cellular, Computational and Integrative Biology (CIBio), University of Trento, Trento, Italy.,Department of Medicine, New York University Langone Medical Center, New York, NY, United States
| | - Alessia Soldano
- Laboratory of Translational Genomics, Department of Cellular, Computational and Integrative Biology (CIBio), University of Trento, Trento, Italy
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9
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Tian Y, Zhang ZC, Han J. Drosophila Studies on Autism Spectrum Disorders. Neurosci Bull 2017; 33:737-746. [PMID: 28795356 DOI: 10.1007/s12264-017-0166-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/23/2017] [Indexed: 02/07/2023] Open
Abstract
In the past decade, numerous genes associated with autism spectrum disorders (ASDs) have been identified. These genes encode key regulators of synaptogenesis, synaptic function, and synaptic plasticity. Drosophila is a prominent model system for ASD studies to define novel genes linked to ASDs and decipher their molecular roles in synaptogenesis, synaptic function, synaptic plasticity, and neural circuit assembly and consolidation. Here, we review Drosophila studies on ASD genes that regulate synaptogenesis, synaptic function, and synaptic plasticity through modulating chromatin remodeling, transcription, protein synthesis and degradation, cytoskeleton dynamics, and synaptic scaffolding.
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Affiliation(s)
- Yao Tian
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Zi Chao Zhang
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China
| | - Junhai Han
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, 210096, China.
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10
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Shank Modulates Postsynaptic Wnt Signaling to Regulate Synaptic Development. J Neurosci 2017; 36:5820-32. [PMID: 27225771 DOI: 10.1523/jneurosci.4279-15.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 04/25/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Prosap/Shank scaffolding proteins regulate the formation, organization, and plasticity of excitatory synapses. Mutations in SHANK family genes are implicated in autism spectrum disorder and other neuropsychiatric conditions. However, the molecular mechanisms underlying Shank function are not fully understood, and no study to date has examined the consequences of complete loss of all Shank proteins in vivo Here we characterize the single Drosophila Prosap/Shank family homolog. Shank is enriched at the postsynaptic membrane of glutamatergic neuromuscular junctions and controls multiple parameters of synapse biology in a dose-dependent manner. Both loss and overexpression of Shank result in defects in synaptic bouton number and maturation. We find that Shank regulates a noncanonical Wnt signaling pathway in the postsynaptic cell by modulating the internalization of the Wnt receptor Fz2. This study identifies Shank as a key component of synaptic Wnt signaling, defining a novel mechanism for how Shank contributes to synapse maturation during neuronal development. SIGNIFICANCE STATEMENT Haploinsufficiency for SHANK3 is one of the most prevalent monogenic causes of autism spectrum disorder, making it imperative to understand how the Shank family regulates neurodevelopment and synapse function. We created the first animal model lacking all Shank proteins and used the Drosophila neuromuscular junction, a model glutamatergic synapse, to characterize the role of Shank at synapses. We identified a novel function of Shank in synapse maturation via regulation of Wnt signaling in the postsynaptic cell.
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11
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Abstract
Drosophila melanogaster originated in tropical Africa before expanding into strikingly different temperate climates in Eurasia and beyond. Here, we find elevated cold tolerance in three distinct geographic regions: beyond the well-studied non-African case, we show that populations from the highlands of Ethiopia and South Africa have significantly increased cold tolerance as well. We observe greater cold tolerance in outbred versus inbred flies, but only in populations with higher inversion frequencies. Each cold-adapted population shows lower inversion frequencies than a closely-related warm-adapted population, suggesting that inversion frequencies may decrease with altitude in addition to latitude. Using the FST-based "Population Branch Excess" statistic (PBE), we found only limited evidence for parallel genetic differentiation at the scale of ∼4 kb windows, specifically between Ethiopian and South African cold-adapted populations. And yet, when we looked for single nucleotide polymorphisms (SNPs) with codirectional frequency change in two or three cold-adapted populations, strong genomic enrichments were observed from all comparisons. These findings could reflect an important role for selection on standing genetic variation leading to "soft sweeps". One SNP showed sufficient codirectional frequency change in all cold-adapted populations to achieve experiment-wide significance: an intronic variant in the synaptic gene Prosap. Another codirectional outlier SNP, at senseless-2, had a strong association with our cold trait measurements, but in the opposite direction as predicted. More generally, proteins involved in neurotransmission were enriched as potential targets of parallel adaptation. The ability to study cold tolerance evolution in a parallel framework will enhance this classic study system for climate adaptation.
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Affiliation(s)
- John E. Pool
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI
| | | | - Justin B. Lack
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI
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12
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Peng F, Zhao Y, Huang X, Chen C, Sun L, Zhuang L, Xue L. Loss of Polo ameliorates APP-induced Alzheimer's disease-like symptoms in Drosophila. Sci Rep 2015; 5:16816. [PMID: 26597721 PMCID: PMC4657023 DOI: 10.1038/srep16816] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 10/15/2015] [Indexed: 12/13/2022] Open
Abstract
The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer’s disease (AD). Despite extensive studies, little is known about the regulation of APP’s functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis.
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Affiliation(s)
- Fei Peng
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yu Zhao
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xirui Huang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Changyan Chen
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lili Sun
- School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, P.R. China
| | - Luming Zhuang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lei Xue
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
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13
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Sturgeon M, Davis D, Albers A, Beatty D, Austin R, Ferguson M, Tounsel B, Liebl FLW. The Notch ligand E3 ligase, Mind Bomb1, regulates glutamate receptor localization in Drosophila. Mol Cell Neurosci 2015; 70:11-21. [PMID: 26596173 DOI: 10.1016/j.mcn.2015.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 11/09/2015] [Accepted: 11/16/2015] [Indexed: 12/29/2022] Open
Abstract
The postsynaptic density (PSD) is a protein-rich network important for the localization of postsynaptic glutamate receptors (GluRs) and for signaling downstream of these receptors. Although hundreds of PSD proteins have been identified, many are functionally uncharacterized. We conducted a reverse genetic screen for mutations that affected GluR localization using Drosophila genes that encode homologs of mammalian PSD proteins. 42.8% of the mutants analyzed exhibited a significant change in GluR localization at the third instar larval neuromuscular junction (NMJ), a model synapse that expresses homologs of AMPA receptors. We identified the E3 ubiquitin ligase, Mib1, which promotes Notch signaling, as a regulator of synaptic GluR localization. Mib1 positively regulates the localization of the GluR subunits GluRIIA, GluRIIB, and GluRIIC. Mutations in mib1 and ubiquitous expression of Mib1 that lacks its ubiquitin ligase activity result in the loss of synaptic GluRIIA-containing receptors. In contrast, overexpression of Mib1 in all tissues increases postsynaptic levels of GluRIIA. Cellular levels of Mib1 are also important for the structure of the presynaptic motor neuron. While deficient Mib1 signaling leads to overgrowth of the NMJ, ubiquitous overexpression of Mib1 results in a reduction in the number of presynaptic motor neuron boutons and branches. These synaptic changes may be secondary to attenuated glutamate release from the presynaptic motor neuron in mib1 mutants as mib1 mutants exhibit significant reductions in the vesicle-associated protein cysteine string protein and in the frequency of spontaneous neurotransmission.
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Affiliation(s)
- Morgan Sturgeon
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Dustin Davis
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Amanda Albers
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Derek Beatty
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Rik Austin
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Matt Ferguson
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Brittany Tounsel
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States
| | - Faith L W Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026, United States.
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Xing G, Gan G, Chen D, Sun M, Yi J, Lv H, Han J, Xie W. Drosophila neuroligin3 regulates neuromuscular junction development and synaptic differentiation. J Biol Chem 2014; 289:31867-31877. [PMID: 25228693 DOI: 10.1074/jbc.m114.574897] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuroligins (Nlgs) are a family of cell adhesion molecules thought to be important for synapse maturation and function. Mammalian studies have shown that different Nlgs have different roles in synaptic maturation and function. In Drosophila melanogaster, the roles of Drosophila neuroligin1 (DNlg1), neuroligin2, and neuroligin4 have been examined. However, the roles of neuroligin3 (dnlg3) in synaptic development and function have not been determined. In this study, we used the Drosophila neuromuscular junctions (NMJs) as a model system to investigate the in vivo role of dnlg3. We showed that DNlg3 was expressed in both the CNS and NMJs where it was largely restricted to the postsynaptic site. We generated dnlg3 mutants and showed that these mutants exhibited an increased bouton number and reduced bouton size compared with the wild-type (WT) controls. Consistent with alterations in bouton properties, pre- and postsynaptic differentiations were affected in dnlg3 mutants. This included abnormal synaptic vesicle endocytosis, increased postsynaptic density length, and reduced GluRIIA recruitment. In addition to impaired synaptic development and differentiation, we found that synaptic transmission was reduced in dnlg3 mutants. Altogether, our data showed that DNlg3 was required for NMJ development, synaptic differentiation, and function.
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Affiliation(s)
- Guanglin Xing
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Guangming Gan
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Dandan Chen
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Mingkuan Sun
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Jukang Yi
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Huihui Lv
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Junhai Han
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Wei Xie
- Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing 210096, China.
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Mhatre SD, Satyasi V, Killen M, Paddock BE, Moir RD, Saunders AJ, Marenda DR. Synaptic abnormalities in a Drosophila model of Alzheimer's disease. Dis Model Mech 2014; 7:373-85. [PMID: 24487408 PMCID: PMC3944497 DOI: 10.1242/dmm.012104] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by memory loss and decreased synaptic function. Advances in transgenic animal models of AD have facilitated our understanding of this disorder, and have aided in the development, speed and efficiency of testing potential therapeutics. Recently, we have described the characterization of a novel model of AD in the fruit fly, Drosophila melanogaster, where we expressed the human AD-associated proteins APP and BACE in the central nervous system of the fly. Here we describe synaptic defects in the larval neuromuscular junction (NMJ) in this model. Our results indicate that expression of human APP and BACE at the larval NMJ leads to defective larval locomotion behavior, decreased presynaptic connections, altered mitochondrial localization in presynaptic motor neurons and decreased postsynaptic protein levels. Treating larvae expressing APP and BACE with the γ-secretase inhibitor L-685,458 suppresses the behavioral defects as well as the pre- and postsynaptic defects. We suggest that this model will be useful to assess and model the synaptic dysfunction normally associated with AD, and will also serve as a powerful in vivo tool for rapid testing of potential therapeutics for AD.
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Affiliation(s)
- Siddhita D Mhatre
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
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16
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Kim YJ, Bao H, Bonanno L, Zhang B, Serpe M. Drosophila Neto is essential for clustering glutamate receptors at the neuromuscular junction. Genes Dev 2012; 26:974-87. [PMID: 22499592 DOI: 10.1101/gad.185165.111] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neurotransmitter receptor recruitment at postsynaptic specializations is key in synaptogenesis, since this step confers functionality to the nascent synapse. The Drosophila neuromuscular junction (NMJ) is a glutamatergic synapse, similar in composition and function to mammalian central synapses. Various mechanisms regulating the extent of postsynaptic ionotropic glutamate receptor (iGluR) clustering have been described, but none are known to be essential for the initial localization and clustering of iGluRs at postsynaptic densities (PSDs). We identified and characterized the Drosophila neto (neuropilin and tolloid-like) as an essential gene required for clustering of iGluRs at the NMJ. Neto colocalizes with the iGluRs at the PSDs in puncta juxtaposing the active zones. neto loss-of-function phenotypes parallel the loss-of-function defects described for iGluRs. The defects in neto mutants are effectively rescued by muscle-specific expression of neto transgenes. Neto clustering at the Drosophila NMJ coincides with and is dependent on iGluRs. Our studies reveal that Drosophila Neto is a novel, essential component of the iGluR complexes and is required for iGluR clustering, organization of PSDs, and synapse functionality.
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Affiliation(s)
- Young-Jun Kim
- Program in Cellular Regulation and Metabolism, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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Abstract
Although WNTs have been long thought of as regulators of cell fate, recent studies highlight their involvement in crucial aspects of synaptic development in the nervous system. Particularly compelling are recent studies of the neuromuscular junction in nematodes, insects, fish and mammals. These studies place WNTs as major determinants of synapse differentiation and neurotransmitter receptor clustering.
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