1
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Ramesh N, Escher M, Turrel O, Lützkendorf J, Matkovic T, Liu F, Sigrist SJ. An antagonism between Spinophilin and Syd-1 operates upstream of memory-promoting presynaptic long-term plasticity. eLife 2023; 12:e86084. [PMID: 37767892 PMCID: PMC10588984 DOI: 10.7554/elife.86084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
We still face fundamental gaps in understanding how molecular plastic changes of synapses intersect with circuit operation to define behavioral states. Here, we show that an antagonism between two conserved regulatory proteins, Spinophilin (Spn) and Syd-1, controls presynaptic long-term plasticity and the maintenance of olfactory memories in Drosophila. While Spn mutants could not trigger nanoscopic active zone remodeling under homeostatic challenge and failed to stably potentiate neurotransmitter release, concomitant reduction of Syd-1 rescued all these deficits. The Spn/Syd-1 antagonism converged on active zone close F-actin, and genetic or acute pharmacological depolymerization of F-actin rescued the Spn deficits by allowing access to synaptic vesicle release sites. Within the intrinsic mushroom body neurons, the Spn/Syd-1 antagonism specifically controlled olfactory memory stabilization but not initial learning. Thus, this evolutionarily conserved protein complex controls behaviorally relevant presynaptic long-term plasticity, also observed in the mammalian brain but still enigmatic concerning its molecular mechanisms and behavioral relevance.
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Affiliation(s)
- Niraja Ramesh
- Institute for Biology/Genetics, Freie Universität BerlinBerlinGermany
| | - Marc Escher
- Institute for Biology/Genetics, Freie Universität BerlinBerlinGermany
| | - Oriane Turrel
- Institute for Biology/Genetics, Freie Universität BerlinBerlinGermany
| | | | - Tanja Matkovic
- Institute for Biology/Genetics, Freie Universität BerlinBerlinGermany
| | - Fan Liu
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität BerlinBerlinGermany
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2
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Dirnberger B, Korona D, Popovic R, Deery MJ, Barber H, Russell S, Lilley KS. Enrichment of Membrane Proteins for Downstream Analysis Using Styrene Maleic Acid Lipid Particles (SMALPs) Extraction. Bio Protoc 2023; 13:e4728. [PMID: 37575399 PMCID: PMC10415199 DOI: 10.21769/bioprotoc.4728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/17/2023] [Accepted: 05/08/2023] [Indexed: 08/15/2023] Open
Abstract
Integral membrane proteins are an important class of cellular proteins. These take part in key cellular processes such as signaling transducing receptors to transporters, many operating within the plasma membrane. More than half of the FDA-approved protein-targeting drugs operate via interaction with proteins that contain at least one membrane-spanning region, yet the characterization and study of their native interactions with therapeutic agents remains a significant challenge. This challenge is due in part to such proteins often being present in small quantities within a cell. Effective solubilization of membrane proteins is also problematic, with the detergents typically employed in solubilizing membranes leading to a loss of functional activity and key interacting partners. In recent years, alternative methods to extract membrane proteins within their native lipid environment have been investigated, with the aim of producing functional nanodiscs, maintaining protein-protein and protein-lipid interactions. A promising approach involves extracting membrane proteins in the form of styrene maleic acid lipid particles (SMALPs) that allow the retention of their native conformation. This extraction method offers many advantages for further protein analysis and allows the study of the protein interactions with other molecules, such as drugs. Here, we describe a protocol for efficient SMALP extraction of functionally active membrane protein complexes within nanodiscs. We showcase the method on the isolation of a low copy number plasma membrane receptor complex, the nicotinic acetylcholine receptor (nAChR), from adult Drosophila melanogaster heads. We demonstrate that these nanodiscs can be used to study native receptor-ligand interactions. This protocol can be applied across many biological scenarios to extract the native conformations of low copy number integral membrane proteins.
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Affiliation(s)
- Benedict Dirnberger
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Dagmara Korona
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Rebeka Popovic
- MRC Toxicology Unit, Gleeson Building, University of Cambridge, Cambridge, United Kingdom
| | - Michael J. Deery
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Helen Barber
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Steven Russell
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Kathryn S. Lilley
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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3
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Ghelani T, Escher M, Thomas U, Esch K, Lützkendorf J, Depner H, Maglione M, Parutto P, Gratz S, Matkovic-Rachid T, Ryglewski S, Walter AM, Holcman D, O‘Connor Giles K, Heine M, Sigrist SJ. Interactive nanocluster compaction of the ELKS scaffold and Cacophony Ca 2+ channels drives sustained active zone potentiation. SCIENCE ADVANCES 2023; 9:eade7804. [PMID: 36800417 PMCID: PMC9937578 DOI: 10.1126/sciadv.ade7804] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 01/17/2023] [Indexed: 06/01/2023]
Abstract
At presynaptic active zones (AZs), conserved scaffold protein architectures control synaptic vesicle (SV) release by defining the nanoscale distribution and density of voltage-gated Ca2+ channels (VGCCs). While AZs can potentiate SV release in the minutes range, we lack an understanding of how AZ scaffold components and VGCCs engage into potentiation. We here establish dynamic, intravital single-molecule imaging of endogenously tagged proteins at Drosophila AZs undergoing presynaptic homeostatic potentiation. During potentiation, the numbers of α1 VGCC subunit Cacophony (Cac) increased per AZ, while their mobility decreased and nanoscale distribution compacted. These dynamic Cac changes depended on the interaction between Cac channel's intracellular carboxyl terminus and the membrane-close amino-terminal region of the ELKS-family protein Bruchpilot, whose distribution compacted drastically. The Cac-ELKS/Bruchpilot interaction was also needed for sustained AZ potentiation. Our single-molecule analysis illustrates how the AZ scaffold couples to VGCC nanoscale distribution and dynamics to establish a state of sustained potentiation.
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Affiliation(s)
- Tina Ghelani
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
- Molecular and Theoretical Neuroscience Leibniz-Forschungs Institut für Molekulare Pharmakologie (FMP) im CharitéCrossOver (CCO) Charité–University Medicine Berlin Charité Campus Mitte, Charité Platz, 110117 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany
| | - Marc Escher
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Ulrich Thomas
- Department of Cellular Neurobiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - Klara Esch
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Janine Lützkendorf
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Harald Depner
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Marta Maglione
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany
- Institute for Chemistry and Biochemistry, SupraFAB, Freie Universität Berlin, Altensteinstr. 23a, 14195 Berlin, Germany
| | - Pierre Parutto
- Group of Applied Mathematics and Computational Biology, IBENS, Ecole Normale Superieure, Paris, France
- Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, Cambridge CB2 0AH, UK
- Churchill College, University of Cambridge, Cambridge CB3 0DS, UK
| | - Scott Gratz
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Tanja Matkovic-Rachid
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Stefanie Ryglewski
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alexander M. Walter
- Molecular and Theoretical Neuroscience Leibniz-Forschungs Institut für Molekulare Pharmakologie (FMP) im CharitéCrossOver (CCO) Charité–University Medicine Berlin Charité Campus Mitte, Charité Platz, 110117 Berlin, Germany
- Department of Neuroscience, University of Copenhagen, Copenhagen 2200, Denmark
| | - David Holcman
- Group of Applied Mathematics and Computational Biology, IBENS, Ecole Normale Superieure, Paris, France
- Churchill College, University of Cambridge, Cambridge CB3 0DS, UK
| | - Kate O‘Connor Giles
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Martin Heine
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118 Magdeburg, Germany
| | - Stephan J. Sigrist
- Institute for Biology and Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany
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4
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Korona D, Dirnberger B, Giachello CNG, Queiroz RML, Popovic R, Müller KH, Minde DP, Deery MJ, Johnson G, Firth LC, Earley FG, Russell S, Lilley KS. Drosophila nicotinic acetylcholine receptor subunits and their native interactions with insecticidal peptide toxins. eLife 2022; 11:74322. [PMID: 35575460 PMCID: PMC9110030 DOI: 10.7554/elife.74322] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 04/19/2022] [Indexed: 12/14/2022] Open
Abstract
Drosophila nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that represent a target for insecticides. Peptide neurotoxins are known to block nAChRs by binding to their target subunits, however, a better understanding of this mechanism is needed for effective insecticide design. To facilitate the analysis of nAChRs we used a CRISPR/Cas9 strategy to generate null alleles for all ten nAChR subunit genes in a common genetic background. We studied interactions of nAChR subunits with peptide neurotoxins by larval injections and styrene maleic acid lipid particles (SMALPs) pull-down assays. For the null alleles, we determined the effects of α-Bungarotoxin (α-Btx) and ω-Hexatoxin-Hv1a (Hv1a) administration, identifying potential receptor subunits implicated in the binding of these toxins. We employed pull-down assays to confirm α-Btx interactions with the Drosophila α5 (Dα5), Dα6, Dα7 subunits. Finally, we report the localisation of fluorescent tagged endogenous Dα6 during Drosophila CNS development. Taken together, this study elucidates native Drosophila nAChR subunit interactions with insecticidal peptide toxins and provides a resource for the in vivo analysis of insect nAChRs.
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Affiliation(s)
- Dagmara Korona
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Benedict Dirnberger
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom.,Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.,Syngenta, Jealott's Hill International Research Centre, Bracknell, United Kingdom
| | - Carlo N G Giachello
- Syngenta, Jealott's Hill International Research Centre, Bracknell, United Kingdom
| | - Rayner M L Queiroz
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Rebeka Popovic
- MRC Toxicology Unit, Gleeson Building, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
| | - Karin H Müller
- Cambridge Advanced Imaging Centre, Department of Physiology, Development and Neuroscience/Anatomy Building, University of Cambridge, Cambridge, United Kingdom
| | - David-Paul Minde
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Michael J Deery
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Glynnis Johnson
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Lucy C Firth
- Syngenta, Jealott's Hill International Research Centre, Bracknell, United Kingdom
| | - Fergus G Earley
- Syngenta, Jealott's Hill International Research Centre, Bracknell, United Kingdom
| | - Steven Russell
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Kathryn S Lilley
- Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
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5
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Petzoldt AG, Götz TWB, Driller JH, Lützkendorf J, Reddy-Alla S, Matkovic-Rachid T, Liu S, Knoche E, Mertel S, Ugorets V, Lehmann M, Ramesh N, Beuschel CB, Kuropka B, Freund C, Stelzl U, Loll B, Liu F, Wahl MC, Sigrist SJ. RIM-binding protein couples synaptic vesicle recruitment to release sites. J Cell Biol 2021; 219:151735. [PMID: 32369542 PMCID: PMC7337501 DOI: 10.1083/jcb.201902059] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 02/03/2020] [Accepted: 04/07/2020] [Indexed: 11/24/2022] Open
Abstract
At presynaptic active zones, arrays of large conserved scaffold proteins mediate fast and temporally precise release of synaptic vesicles (SVs). SV release sites could be identified by clusters of Munc13, which allow SVs to dock in defined nanoscale relation to Ca2+ channels. We here show in Drosophila that RIM-binding protein (RIM-BP) connects release sites physically and functionally to the ELKS family Bruchpilot (BRP)-based scaffold engaged in SV recruitment. The RIM-BP N-terminal domain, while dispensable for SV release site organization, was crucial for proper nanoscale patterning of the BRP scaffold and needed for SV recruitment of SVs under strong stimulation. Structural analysis further showed that the RIM-BP fibronectin domains form a “hinge” in the protein center, while the C-terminal SH3 domain tandem binds RIM, Munc13, and Ca2+ channels release machinery collectively. RIM-BPs’ conserved domain architecture seemingly provides a relay to guide SVs from membrane far scaffolds into membrane close release sites.
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Affiliation(s)
- Astrid G Petzoldt
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Torsten W B Götz
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Jan Heiner Driller
- Freie Universität Berlin, Institute of Chemistry and Biochemistry/Structural Biochemistry Berlin, Berlin, Germany
| | - Janine Lützkendorf
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Suneel Reddy-Alla
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | | | - Sunbin Liu
- Freie Universität Berlin, Institute of Chemistry and Biochemistry/Structural Biochemistry Berlin, Berlin, Germany
| | - Elena Knoche
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Sara Mertel
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Vladimir Ugorets
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V., Campus Berlin-Buch, Berlin, Germany
| | - Niraja Ramesh
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | | | - Benno Kuropka
- Universität Berlin, Institute for Chemistry and Biochemistry, Berlin, Germany
| | - Christian Freund
- Universität Berlin, Institute for Chemistry and Biochemistry, Berlin, Germany
| | - Ulrich Stelzl
- Institut für Pharmazeutische Wissenschaften, Graz, Austria
| | - Bernhard Loll
- Freie Universität Berlin, Institute of Chemistry and Biochemistry/Structural Biochemistry Berlin, Berlin, Germany
| | - Fan Liu
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V., Campus Berlin-Buch, Berlin, Germany
| | - Markus C Wahl
- Freie Universität Berlin, Institute of Chemistry and Biochemistry/Structural Biochemistry Berlin, Berlin, Germany.,Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany.,NeuroCure, Charité, Berlin, Germany
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6
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Chi H, Sun L, Shiu RH, Han R, Hsieh CP, Wei TM, Lo CC, Chang HY, Sang TK. Cleavage of human tau at Asp421 inhibits hyperphosphorylated tau induced pathology in a Drosophila model. Sci Rep 2020; 10:13482. [PMID: 32778728 PMCID: PMC7417559 DOI: 10.1038/s41598-020-70423-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 07/29/2020] [Indexed: 11/09/2022] Open
Abstract
Hyperphosphorylated and truncated tau variants are enriched in neuropathological aggregates in diseases known as tauopathies. However, whether the interaction of these posttranslational modifications affects tau toxicity as a whole remains unresolved. By expressing human tau with disease-related Ser/Thr residues to simulate hyperphosphorylation, we show that despite severe neurodegeneration in full-length tau, with the truncation at Asp421, the toxicity is ameliorated. Cytological and biochemical analyses reveal that hyperphosphorylated full-length tau distributes in the soma, the axon, and the axonal terminal without evident distinction, whereas the Asp421-truncated version is mostly restricted from the axonal terminal. This discrepancy is correlated with the fact that fly expressing hyperphosphorylated full-length tau, but not Asp421-cleaved one, develops axonopathy lesions, including axonal spheroids and aberrant actin accumulations. The reduced presence of hyperphosphorylated tau in the axonal terminal is corroborated with the observation that flies expressing Asp421-truncated variants showed less motor deficit, suggesting synaptic function is preserved. The Asp421 cleavage of tau is a proteolytic product commonly found in the neurofibrillary tangles. Our finding suggests the coordination of different posttranslational modifications on tau may have an unexpected impact on the protein subcellular localization and cytotoxicity, which may be valuable when considering tau for therapeutic purposes.
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Affiliation(s)
- Hao Chi
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Lee Sun
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Ren-Huei Shiu
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Rui Han
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chien-Ping Hsieh
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Tzu-Min Wei
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chung-Chuan Lo
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Brain Research Center, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Hui-Yun Chang
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Department of Medical Science, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Tzu-Kang Sang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan. .,Brain Research Center, National Tsing Hua University, Hsinchu, 30013, Taiwan. .,Department of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan.
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7
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Huang S, Piao C, Beuschel CB, Götz T, Sigrist SJ. Presynaptic Active Zone Plasticity Encodes Sleep Need in Drosophila. Curr Biol 2020; 30:1077-1091.e5. [PMID: 32142702 DOI: 10.1016/j.cub.2020.01.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 09/26/2019] [Accepted: 01/07/2020] [Indexed: 01/04/2023]
Abstract
Sleep is universal across species and essential for quality of life and health, as evidenced by the consequences of sleep loss. Sleep might homeostatically normalize synaptic gains made over wake states in order to reset information processing and storage and support learning, and sleep-associated synaptic (ultra)structural changes have been demonstrated recently. However, causal relationships between the molecular and (ultra)structural status of synapses, sleep homeostatic regulation, and learning processes have yet to be established. We show here that the status of the presynaptic active zone can directly control sleep in Drosophila. Short sleep mutants showed a brain-wide upregulation of core presynaptic scaffold proteins and release factors. Increasing the gene copy number of ELKS-family scaffold master organizer Bruchpilot (BRP) not only mimicked changes in the active zone scaffold and release proteins but importantly provoked sleep in a dosage-dependent manner, qualitatively and quantitatively reminiscent of sleep deprivation effects. Conversely, reducing the brp copy number decreased sleep in short sleep mutant backgrounds, suggesting a specific role of the active zone plasticity in homeostatic sleep regulation. Finally, elimination of BRP specifically in the sleep-promoting R2 neurons of 4xBRP animals partially restored sleep patterns and rescued learning deficits. Our results suggest that the presynaptic active zone plasticity driven by BRP operates as a sleep homeostatic actuator that also restricts periods of effective learning.
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Affiliation(s)
- Sheng Huang
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany
| | - Chengji Piao
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Christine B Beuschel
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Torsten Götz
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany.
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8
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Kanellopoulos AK, Mariano V, Spinazzi M, Woo YJ, McLean C, Pech U, Li KW, Armstrong JD, Giangrande A, Callaerts P, Smit AB, Abrahams BS, Fiala A, Achsel T, Bagni C. Aralar Sequesters GABA into Hyperactive Mitochondria, Causing Social Behavior Deficits. Cell 2020; 180:1178-1197.e20. [DOI: 10.1016/j.cell.2020.02.044] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/01/2020] [Accepted: 02/18/2020] [Indexed: 12/21/2022]
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9
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Driller JH, Lützkendorf J, Depner H, Siebert M, Kuropka B, Weise C, Piao C, Petzoldt AG, Lehmann M, Stelzl U, Zahedi R, Sickmann A, Freund C, Sigrist SJ, Wahl MC. Phosphorylation of the Bruchpilot N-terminus in Drosophila unlocks axonal transport of active zone building blocks. J Cell Sci 2019; 132:jcs.225151. [PMID: 30745339 DOI: 10.1242/jcs.225151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/24/2019] [Indexed: 01/31/2023] Open
Abstract
Protein scaffolds at presynaptic active zone membranes control information transfer at synapses. For scaffold biogenesis and maintenance, scaffold components must be safely transported along axons. A spectrum of kinases has been suggested to control transport of scaffold components, but direct kinase-substrate relationships and operational principles steering phosphorylation-dependent active zone protein transport are presently unknown. Here, we show that extensive phosphorylation of a 150-residue unstructured region at the N-terminus of the highly elongated Bruchpilot (BRP) active zone protein is crucial for ordered active zone precursor transport in Drosophila Point mutations that block SRPK79D kinase-mediated phosphorylation of the BRP N-terminus interfered with axonal transport, leading to BRP-positive axonal aggregates that also contain additional active zone scaffold proteins. Axonal aggregates formed only in the presence of non-phosphorylatable BRP isoforms containing the SRPK79D-targeted N-terminal stretch. We assume that specific active zone proteins are pre-assembled in transport packages and are thus co-transported as functional scaffold building blocks. Our results suggest that transient post-translational modification of a discrete unstructured domain of the master scaffold component BRP blocks oligomerization of these building blocks during their long-range transport.
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Affiliation(s)
- Jan H Driller
- Laboratory of Structural Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany
| | - Janine Lützkendorf
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany
| | - Harald Depner
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany
| | - Matthias Siebert
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany
| | - Benno Kuropka
- Laboratory of Protein Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, D-14195 Berlin, Germany
| | - Christoph Weise
- Laboratory of Protein Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, D-14195 Berlin, Germany
| | - Chengji Piao
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany
| | - Astrid G Petzoldt
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany.,NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Martin Lehmann
- Cellular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, D-13125 Berlin, Germany
| | - Ulrich Stelzl
- Pharmaceutical Chemistry, Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1/I, A-8010 Graz, Austria
| | - René Zahedi
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, D-44139 Dortmund, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Bunsen-Kirchhoff-Straße 11, D-44139 Dortmund, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, D-14195 Berlin, Germany
| | - Stephan J Sigrist
- Laboratory of Genetics, Institute of Biology, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany .,NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Markus C Wahl
- Laboratory of Structural Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 6, D-14195 Berlin, Germany .,Macromolecular Crystallography, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, D-12489 Berlin, Germany
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10
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ER Lipid Defects in Neuropeptidergic Neurons Impair Sleep Patterns in Parkinson's Disease. Neuron 2018; 98:1155-1169.e6. [PMID: 29887339 DOI: 10.1016/j.neuron.2018.05.022] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/16/2018] [Accepted: 05/14/2018] [Indexed: 01/23/2023]
Abstract
Parkinson's disease patients report disturbed sleep patterns long before motor dysfunction. Here, in parkin and pink1 models, we identify circadian rhythm and sleep pattern defects and map these to specific neuropeptidergic neurons in fly models and in hypothalamic neurons differentiated from patient induced pluripotent stem cells (iPSCs). Parkin and Pink1 control the clearance of mitochondria by protein ubiquitination. Although we do not observe major defects in mitochondria of mutant neuropeptidergic neurons, we do find an excess of endoplasmic reticulum-mitochondrial contacts. These excessive contact sites cause abnormal lipid trafficking that depletes phosphatidylserine from the endoplasmic reticulum (ER) and disrupts the production of neuropeptide-containing vesicles. Feeding mutant animals phosphatidylserine rescues neuropeptidergic vesicle production and acutely restores normal sleep patterns in mutant animals. Hence, sleep patterns and circadian disturbances in Parkinson's disease models are explained by excessive ER-mitochondrial contacts, and blocking their formation or increasing phosphatidylserine levels rescues the defects in vivo.
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11
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McInnes J, Wierda K, Snellinx A, Bounti L, Wang YC, Stancu IC, Apóstolo N, Gevaert K, Dewachter I, Spires-Jones TL, De Strooper B, De Wit J, Zhou L, Verstreken P. Synaptogyrin-3 Mediates Presynaptic Dysfunction Induced by Tau. Neuron 2018; 97:823-835.e8. [DOI: 10.1016/j.neuron.2018.01.022] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 12/07/2017] [Accepted: 01/09/2018] [Indexed: 11/25/2022]
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12
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Singh V, Sharma RK, Athilingam T, Sinha P, Sinha N, Thakur AK. NMR Spectroscopy-based Metabolomics of Drosophila Model of Huntington's Disease Suggests Altered Cell Energetics. J Proteome Res 2017; 16:3863-3872. [PMID: 28871787 DOI: 10.1021/acs.jproteome.7b00491] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder induced by aggregation of the pathological form of Huntingtin protein that has expanded polyglutamine (polyQ) repeats. In the Drosophila model, for instance, expression of transgenes with polyQ repeats induces HD-like pathologies, progressively correlating with the increasing lengths of these repeats. Previous studies on both animal models and clinical samples have revealed metabolite imbalances during HD progression. To further explore the physiological processes linked to metabolite imbalances during HD, we have investigated the 1D 1H NMR spectroscopy-based metabolomics profile of Drosophila HD model. Using multivariate analysis (PCA and PLS-DA) of metabolites obtained from methanolic extracts of fly heads displaying retinal deformations due to polyQ overexpression, we show that the metabolite imbalance during HD is likely to affect cell energetics. Six out of the 35 metabolites analyzed, namely, nicotinamide adenine dinucleotide (NAD), lactate, pyruvate, succinate, sarcosine, and acetoin, displayed segregation with progressive severity of HD. Specifically, HD progression was seen to be associated with reduction in NAD and increase in lactate-to-pyruvate ratio. Furthermore, comparative analysis of fly HD metabolome with those of mouse HD model and HD human patients revealed comparable metabolite imbalances, suggesting altered cellular energy homeostasis. These findings thus raise the possibility of therapeutic interventions for HD via modulation of cellular energetics.
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Affiliation(s)
- Virender Singh
- Biological Science and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
| | - Raj Kumar Sharma
- Centre of Biomedical Research, SGPGIMS Campus , Lucknow 226014, India
| | | | - Pradip Sinha
- Biological Science and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
| | - Neeraj Sinha
- Centre of Biomedical Research, SGPGIMS Campus , Lucknow 226014, India
| | - Ashwani Kumar Thakur
- Biological Science and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
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13
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Pamudurti NR, Bartok O, Jens M, Ashwal-Fluss R, Stottmeister C, Ruhe L, Hanan M, Wyler E, Perez-Hernandez D, Ramberger E, Shenzis S, Samson M, Dittmar G, Landthaler M, Chekulaeva M, Rajewsky N, Kadener S. Translation of CircRNAs. Mol Cell 2017; 66:9-21.e7. [PMID: 28344080 PMCID: PMC5387669 DOI: 10.1016/j.molcel.2017.02.021] [Citation(s) in RCA: 1235] [Impact Index Per Article: 176.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 01/04/2017] [Accepted: 02/21/2017] [Indexed: 12/17/2022]
Abstract
Circular RNAs (circRNAs) are abundant and evolutionarily conserved RNAs of largely unknown function. Here, we show that a subset of circRNAs is translated in vivo. By performing ribosome footprinting from fly heads, we demonstrate that a group of circRNAs is associated with translating ribosomes. Many of these ribo-circRNAs use the start codon of the hosting mRNA, are bound by membrane-associated ribosomes, and have evolutionarily conserved termination codons. In addition, we found that a circRNA generated from the muscleblind locus encodes a protein, which we detected in fly head extracts by mass spectrometry. Next, by performing in vivo and in vitro translation assays, we show that UTRs of ribo-circRNAs (cUTRs) allow cap-independent translation. Moreover, we found that starvation and FOXO likely regulate the translation of a circMbl isoform. Altogether, our study provides strong evidence for translation of circRNAs, revealing the existence of an unexplored layer of gene activity.
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Affiliation(s)
- Nagarjuna Reddy Pamudurti
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Osnat Bartok
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Marvin Jens
- Systems Biology of Gene Regulatory Elements, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Reut Ashwal-Fluss
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Christin Stottmeister
- Systems Biology of Gene Regulatory Elements, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Larissa Ruhe
- Non Coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Mor Hanan
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Emanuel Wyler
- RNA Biology and Posttranscriptional Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Daniel Perez-Hernandez
- Mass Spectrometry Core Unit, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Evelyn Ramberger
- Mass Spectrometry Core Unit, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Shlomo Shenzis
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Moshe Samson
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gunnar Dittmar
- Mass Spectrometry Core Unit, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Markus Landthaler
- RNA Biology and Posttranscriptional Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Marina Chekulaeva
- Non Coding RNAs and Mechanisms of Cytoplasmic Gene Regulation, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
| | - Sebastian Kadener
- Biological Chemistry Department, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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14
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Muhammad K, Reddy-Alla S, Driller JH, Schreiner D, Rey U, Böhme MA, Hollmann C, Ramesh N, Depner H, Lützkendorf J, Matkovic T, Götz T, Bergeron DD, Schmoranzer J, Goettfert F, Holt M, Wahl MC, Hell SW, Scheiffele P, Walter AM, Loll B, Sigrist SJ. Presynaptic spinophilin tunes neurexin signalling to control active zone architecture and function. Nat Commun 2015; 6:8362. [PMID: 26471740 PMCID: PMC4633989 DOI: 10.1038/ncomms9362] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/13/2015] [Indexed: 11/17/2022] Open
Abstract
Assembly and maturation of synapses at the Drosophila neuromuscular junction
(NMJ) depend on trans-synaptic neurexin/neuroligin signalling, which is promoted by
the scaffolding protein Syd-1 binding to neurexin. Here we report that the scaffold
protein spinophilin binds to the C-terminal portion of neurexin and is needed to
limit neurexin/neuroligin signalling by acting antagonistic to Syd-1. Loss of
presynaptic spinophilin results in the formation of excess, but atypically small
active zones. Neuroligin-1/neurexin-1/Syd-1 levels are increased at
spinophilin mutant NMJs, and removal of single copies of the
neurexin-1, Syd-1 or neuroligin-1 genes suppresses the
spinophilin-active zone phenotype. Evoked transmission is strongly reduced at
spinophilin terminals, owing to a severely reduced release probability at
individual active zones. We conclude that presynaptic spinophilin fine-tunes
neurexin/neuroligin signalling to control active zone number and functionality,
thereby optimizing them for action potential-induced exocytosis. Synaptic assembly depends on trans-synaptic Neurexin/Neuroligin
signalling. Here, Muhammad et al. show that Spinophilin, a pre-synaptic
scaffolding protein, interacts with Neurexin, in competition with Syd-1, to regulate the
formation and function of synaptic active zones at Drosophila neuromuscular
junctions.
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Affiliation(s)
- Karzan Muhammad
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Suneel Reddy-Alla
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Jan H Driller
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Dietmar Schreiner
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, Basel 4056, Switzerland
| | - Ulises Rey
- NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | | | - Niraja Ramesh
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany
| | - Harald Depner
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | - Tanja Matkovic
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | - Torsten Götz
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
| | | | - Jan Schmoranzer
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany.,Leibniz Institut für Molekulare Pharmakologie, Robert-Roessle-Strasse 10, Berlin 13125, Germany
| | - Fabian Goettfert
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Mathew Holt
- VIB Center for the Biology of Disease, Herestraat 49, Leuven 3000, Belgium
| | - Markus C Wahl
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Peter Scheiffele
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, Basel 4056, Switzerland
| | - Alexander M Walter
- NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany.,Leibniz Institut für Molekulare Pharmakologie, Robert-Roessle-Strasse 10, Berlin 13125, Germany
| | - Bernhard Loll
- Freie Universität Berlin, Institut für Chemie und Biochemie /Strukturbiochmie, Takustrasse 6, Berlin D-14195, Germany
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, Berlin 14195, Germany.,NeuroCure, Charité, Charitéplatz 1, Berlin 10117, Germany
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15
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Pazos Obregón F, Papalardo C, Castro S, Guerberoff G, Cantera R. Putative synaptic genes defined from a Drosophila whole body developmental transcriptome by a machine learning approach. BMC Genomics 2015; 16:694. [PMID: 26370122 PMCID: PMC4570697 DOI: 10.1186/s12864-015-1888-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 09/01/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Assembly and function of neuronal synapses require the coordinated expression of a yet undetermined set of genes. Although roughly a thousand genes are expected to be important for this function in Drosophila melanogaster, just a few hundreds of them are known so far. RESULTS In this work we trained three learning algorithms to predict a "synaptic function" for genes of Drosophila using data from a whole-body developmental transcriptome published by others. Using statistical and biological criteria to analyze and combine the predictions, we obtained a gene catalogue that is highly enriched in genes of relevance for Drosophila synapse assembly and function but still not recognized as such. CONCLUSIONS The utility of our approach is that it reduces the number of genes to be tested through hypothesis-driven experimentation.
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Affiliation(s)
- Flavio Pazos Obregón
- Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, PC 11600, Montevideo, Uruguay.
| | - Cecilia Papalardo
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Sebastián Castro
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Gustavo Guerberoff
- Instituto de Matemática y Estadística "Prof. Ing. Rafael Laguardia", Facultad de Ingeniería, Universidad de la República, Montevideo, Uruguay.
| | - Rafael Cantera
- Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, PC 11600, Montevideo, Uruguay.
- Zoology Department, Stockholm University, Stockholm, Sweden.
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16
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Siebert M, Böhme MA, Driller JH, Babikir H, Mampell MM, Rey U, Ramesh N, Matkovic T, Holton N, Reddy-Alla S, Göttfert F, Kamin D, Quentin C, Klinedinst S, Andlauer TF, Hell SW, Collins CA, Wahl MC, Loll B, Sigrist SJ. A high affinity RIM-binding protein/Aplip1 interaction prevents the formation of ectopic axonal active zones. eLife 2015; 4. [PMID: 26274777 PMCID: PMC4536467 DOI: 10.7554/elife.06935] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 07/24/2015] [Indexed: 12/17/2022] Open
Abstract
Synaptic vesicles (SVs) fuse at active zones (AZs) covered by a protein scaffold, at Drosophila synapses comprised of ELKS family member Bruchpilot (BRP) and RIM-binding protein (RBP). We here demonstrate axonal co-transport of BRP and RBP using intravital live imaging, with both proteins co-accumulating in axonal aggregates of several transport mutants. RBP, via its C-terminal Src-homology 3 (SH3) domains, binds Aplip1/JIP1, a transport adaptor involved in kinesin-dependent SV transport. We show in atomic detail that RBP C-terminal SH3 domains bind a proline-rich (PxxP) motif of Aplip1/JIP1 with submicromolar affinity. Pointmutating this PxxP motif provoked formation of ectopic AZ-like structures at axonal membranes. Direct interactions between AZ proteins and transport adaptors seem to provide complex avidity and shield synaptic interaction surfaces of pre-assembled scaffold protein transport complexes, thus, favouring physiological synaptic AZ assembly over premature assembly at axonal membranes. DOI:http://dx.doi.org/10.7554/eLife.06935.001 To pass on information, the neurons that make up the nervous system connect at structures known as synapses. Chemical messengers called neurotransmitters are released from one neuron, and travel across the synapse to trigger a response in the neighbouring cell. The formation of new synapses plays an important role in learning and memory, but many aspects of this process are not well understood. In a specific region of the synapse called the active zone, a scaffold of proteins helps to release the neurotransmitters. These proteins are made in the cell body of the neuron, and are then transported to the end of the long, thin axons that protrude from the cell body. This presents a challenge for the cell, because the components of the active zone scaffold must be correctly targeted to the synapse at the end of the axon, ensuring the active zone scaffold assembles only at its proper location. Siebert, Böhme et al. studied how some of the proteins that are found in the active zone scaffold of the fruit fly Drosophila are transported along axons. Labelling the proteins with fluorescent markers allowed their movement to be examined under a microscope in living Drosophila larvae. The results showed that two of the proteins—known as BRP and RBP—are transported along the axons together. Further investigation revealed that a transport adaptor protein called Aplip1, which binds to RBP, is required for this movement. Siebert, Böhme et al. established the structure of the part of RBP where this interaction occurs, and found that mutating this region causes premature active zone scaffold assembly in the axonal part of the neuron. The interaction between RBP and Aplip1 is very strong, and this helps to prevent the scaffold assembling before it has reached the correct part of the neuron. Exactly how the transport adaptor and active zone protein are separated once they reach their final destination (the synapse) remains to be discovered. DOI:http://dx.doi.org/10.7554/eLife.06935.002
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Affiliation(s)
- Matthias Siebert
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Mathias A Böhme
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Jan H Driller
- Institute of Chemistry and Biochemisty/Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Husam Babikir
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Malou M Mampell
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Ulises Rey
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Niraja Ramesh
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Tanja Matkovic
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Nicole Holton
- Institute of Chemistry and Biochemisty/Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Suneel Reddy-Alla
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Fabian Göttfert
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dirk Kamin
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Christine Quentin
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Susan Klinedinst
- Department of Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Till Fm Andlauer
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
| | - Stefan W Hell
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Catherine A Collins
- Department of Molecular Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
| | - Markus C Wahl
- Institute of Chemistry and Biochemisty/Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Bernhard Loll
- Institute of Chemistry and Biochemisty/Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Berlin, Germany
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17
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Andlauer TFM, Scholz-Kornehl S, Tian R, Kirchner M, Babikir HA, Depner H, Loll B, Quentin C, Gupta VK, Holt MG, Dipt S, Cressy M, Wahl MC, Fiala A, Selbach M, Schwärzel M, Sigrist SJ. Drep-2 is a novel synaptic protein important for learning and memory. eLife 2014; 3. [PMID: 25392983 PMCID: PMC4229683 DOI: 10.7554/elife.03895] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 10/13/2014] [Indexed: 12/16/2022] Open
Abstract
CIDE-N domains mediate interactions between the DNase Dff40/CAD and its inhibitor Dff45/ICAD. In this study, we report that the CIDE-N protein Drep-2 is a novel synaptic protein important for learning and behavioral adaptation. Drep-2 was found at synapses throughout the Drosophila brain and was strongly enriched at mushroom body input synapses. It was required within Kenyon cells for normal olfactory short- and intermediate-term memory. Drep-2 colocalized with metabotropic glutamate receptors (mGluRs). Chronic pharmacological stimulation of mGluRs compensated for drep-2 learning deficits, and drep-2 and mGluR learning phenotypes behaved non-additively, suggesting that Drep 2 might be involved in effective mGluR signaling. In fact, Drosophila fragile X protein mutants, shown to benefit from attenuation of mGluR signaling, profited from the elimination of drep-2. Thus, Drep-2 is a novel regulatory synaptic factor, probably intersecting with metabotropic signaling and translational regulation. DOI:http://dx.doi.org/10.7554/eLife.03895.001 Synapses are specialized structures that connect nerve cells to one another and allow information to be transmitted between the cells. Synapses are essential for learning and storing memories. Many proteins that regulate how signals are transmitted at synapses have already been studied. In this manner, much has been learned about their function in learning and memory. Cells can commit suicide by a process called apoptosis, also known as programmed cell death. Apoptosis is not only triggered in damaged cells but is also necessary for an organism to develop correctly. In fruit flies, the protein Drep-2 is a member of a family of proteins that degrade the DNA of cells that undergo apoptosis. Andlauer et al. found no evidence that Drep-2 plays a role in apoptosis, but have now found Drep-2 at the synapses of the brain of the fruit fly Drosophila. Drep-2 could be observed in close proximity to another type of protein called metabotropic glutamate receptors. Metabotropic glutamate receptors and their signaling pathways are important for regulating certain changes to the synapses that mediate learning processes. Indeed, Andlauer et al. found that flies that have lost the gene that produces Drep-2 were unable to remember smells when these were paired with a punishment. Stimulating the regulatory glutamate receptors with drugs helped to overcome learning deficits that result from the lack of Drep-2. Alterations in the production of a protein called FMRP cause fragile X syndrome in humans, the most common form of hereditary mental disability originating from a single gene defect. Flies lacking the FMRP protein show learning deficits that are very similar to the ones seen in flies that cannot produce Drep-2. However, Andlauer et al. observed that flies lacking both Drep-2 and FMRP can learn normally. Exactly how Drep-2 works in synapses to help with memory formation remains to be discovered, although there are indications that it boosts the effects of signaling from the glutamate receptors and counteracts FMRP. Further research will be needed to establish whether the mammalian proteins related to Drep-2 perform similar roles in the brains of mammals. DOI:http://dx.doi.org/10.7554/eLife.03895.002
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Affiliation(s)
- Till F M Andlauer
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | | | - Rui Tian
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Marieluise Kirchner
- Department of Cell Signalling and Mass Spectrometry, Max-Delbrück-Centrum für Molekulare Medizin, Berlin-Buch, Germany
| | - Husam A Babikir
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Harald Depner
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Bernhard Loll
- Institute of Chemistry and Biochemisty, Freie Universität Berlin, Berlin, Germany
| | - Christine Quentin
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Varun K Gupta
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Matthew G Holt
- Department Laboratory of Glia Biology, Vlaams Instituut voor Biotechnologie (VIB) Center for the Biology of Disease, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Shubham Dipt
- Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Michael Cressy
- Department of Neuroscience, Cold Spring Harbor Laboratory, Cold Spring Harbor, United States
| | - Markus C Wahl
- Institute of Chemistry and Biochemisty, Freie Universität Berlin, Berlin, Germany
| | - André Fiala
- Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Matthias Selbach
- Department of Cell Signalling and Mass Spectrometry, Max-Delbrück-Centrum für Molekulare Medizin, Berlin-Buch, Germany
| | - Martin Schwärzel
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Stephan J Sigrist
- Genetics, Institute of Biology, Freie Universität Berlin, Berlin, Germany
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