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Tahraoui-Bories J, Mérien A, González-Barriga A, Lainé J, Leteur C, Polvèche H, Carteron A, De Lamotte JD, Nicoleau C, Polentes J, Jarrige M, Gomes-Pereira M, Ventre E, Poydenot P, Furling D, Schaeffer L, Legay C, Martinat C. MBNL-dependent impaired development within the neuromuscular system in myotonic dystrophy type 1. Neuropathol Appl Neurobiol 2023; 49:e12876. [PMID: 36575942 PMCID: PMC10107781 DOI: 10.1111/nan.12876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/27/2022] [Accepted: 12/12/2022] [Indexed: 12/29/2022]
Abstract
AIMS Myotonic dystrophy type I (DM1) is one of the most frequent muscular dystrophies in adults. Although DM1 has long been considered mainly a muscle disorder, growing evidence suggests the involvement of peripheral nerves in the pathogenicity of DM1 raising the question of whether motoneurons (MNs) actively contribute to neuromuscular defects in DM1. METHODS By using micropatterned 96-well plates as a coculture platform, we generated a functional neuromuscular model combining DM1 and muscleblind protein (MBNL) knock-out human-induced pluripotent stem cells-derived MNs and human healthy skeletal muscle cells. RESULTS This approach led to the identification of presynaptic defects which affect the formation or stability of the neuromuscular junction at an early developmental stage. These neuropathological defects could be reproduced by the loss of RNA-binding MBNL proteins, whose loss of function in vivo is associated with muscular defects associated with DM1. These experiments indicate that the functional defects associated with MNs can be directly attributed to MBNL family proteins. Comparative transcriptomic analyses also revealed specific neuronal-related processes regulated by these proteins that are commonly misregulated in DM1. CONCLUSIONS Beyond the application to DM1, our approach to generating a robust and reliable human neuromuscular system should facilitate disease modelling studies and drug screening assays.
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Affiliation(s)
| | - Antoine Mérien
- INSERM/UEVE UMR 861, Université Paris Saclay, I-STEM, Corbeil-Essonnes, France
| | - Anchel González-Barriga
- INSERM, Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, Paris, France
| | - Jeanne Lainé
- INSERM, Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, Paris, France
| | | | | | | | | | | | | | | | - Mário Gomes-Pereira
- INSERM, Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, Paris, France
| | | | | | - Denis Furling
- INSERM, Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, Paris, France
| | - Laurent Schaeffer
- INMG, INSERM U1217, CNRS UMR5310, Université Lyon 1, Université de Lyon, Hospices Civils de Lyon, Lyon, France
| | - Claire Legay
- CNRS, SPINN-Saint-Pères Paris Institute for the Neurosciences, Université Paris Cité, Paris, France
| | - Cécile Martinat
- INSERM/UEVE UMR 861, Université Paris Saclay, I-STEM, Corbeil-Essonnes, France
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2
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Huang TT, Smith R, Bacos K, Song DY, Faull RM, Waldvogel HJ, Li JY. No symphony without bassoon and piccolo: changes in synaptic active zone proteins in Huntington's disease. Acta Neuropathol Commun 2020; 8:77. [PMID: 32493491 PMCID: PMC7268643 DOI: 10.1186/s40478-020-00949-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/19/2020] [Indexed: 11/10/2022] Open
Abstract
Prominent features of HD neuropathology are the intranuclear and cytoplasmic inclusions of huntingtin and striatal and cortical neuronal cell death. Recently, synaptic defects have been reported on HD-related studies, including impairment of neurotransmitter release and alterations of synaptic components. However, the definite characteristics of synapse dysfunction and the underlying mechanisms remain largely unknown. We studied the gene expression levels and patterns of a number of proteins forming the cytoskeletal matrix of the presynaptic active zones in HD transgenic mice (R6/1), in hippocampal neuronal cultures overexpressing mutant huntingtin and in postmortem brain tissues of HD patients. To investigate the interactions between huntingtin and active proteins, we performed confocal microscopic imaging and immunoprecipitation in mouse and HEK 293 cell line models. The mRNA and protein levels of Bassoon were reduced in mouse and cell culture models of HD and in brain tissues of patients with HD. Moreover, a striking re-distribution of a complex of proteins including Bassoon, Piccolo and Munc 13-1 from the cytoplasm and synapses into intranuclear huntingtin aggregates with loss of active zone proteins and dendritic spines. This re-localization was age-dependent and coincided with the formation of huntingtin aggregates. Using co-immunoprecipitation, we demonstrated that huntingtin interacts with Bassoon, and that this interaction is likely mediated by a third linking protein. Three structural proteins involved in neurotransmitter release in the presynaptic active zones of neurons are altered in expression and that the proteins are redistributed from their normal functional site into mutant huntingtin aggregates.
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3
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Hagiwara A, Sugiyama N, Ohtsuka T. Impaired experience-dependent maternal care in presynaptic active zone protein CAST-deficient dams. Sci Rep 2020; 10:5238. [PMID: 32251313 PMCID: PMC7090055 DOI: 10.1038/s41598-020-62072-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 03/09/2020] [Indexed: 11/24/2022] Open
Abstract
Although sociological studies affirm the importance of parental care in the survival of offspring, maltreatment—including child neglect—remains prevalent in many countries. While child neglect is well known to affect child development, the causes of maternal neglect are poorly understood. Here, we found that female mice with a deletion mutation of CAST (a presynaptic release-machinery protein) showed significantly reduced weaning rate when primiparous and a recovered rate when multiparous. Indeed, when nurturing, primiparous and nulliparous CAST knock out (KO) mice exhibited less crouching time than control mice and moved greater distances. Contrary to expectations, plasma oxytocin (OXT) was not significantly reduced in CAST KO mice even though terminals of magnocellular neurons in the posterior pituitary expressed CAST. We further found that compared with control mice, CAST KO mice drank significantly less water when nurturing and had a greater preference for sucrose during pregnancy. We suggest that deficiency in presynaptic release-machinery protein impairs the facilitation of some maternal behaviours, which can be compensated for by experience and learning.
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Affiliation(s)
- Akari Hagiwara
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Naoko Sugiyama
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Toshihisa Ohtsuka
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
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4
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Moser T, Grabner CP, Schmitz F. Sensory Processing at Ribbon Synapses in the Retina and the Cochlea. Physiol Rev 2020; 100:103-144. [DOI: 10.1152/physrev.00026.2018] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In recent years, sensory neuroscientists have made major efforts to dissect the structure and function of ribbon synapses which process sensory information in the eye and ear. This review aims to summarize our current understanding of two key aspects of ribbon synapses: 1) their mechanisms of exocytosis and endocytosis and 2) their molecular anatomy and physiology. Our comparison of ribbon synapses in the cochlea and the retina reveals convergent signaling mechanisms, as well as divergent strategies in different sensory systems.
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Affiliation(s)
- Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
| | - Chad P. Grabner
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
| | - Frank Schmitz
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
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5
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Buceta I, Elezgarai I, Rico‐Barrio I, Gerrikagoitia I, Puente N, Grandes P. Deletion of the cannabinoid CB
1
receptor impacts on the ultrastructure of the cerebellar parallel fiber‐Purkinje cell synapses. J Comp Neurol 2019; 528:1041-1052. [DOI: 10.1002/cne.24808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/09/2019] [Accepted: 10/31/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Ianire Buceta
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
| | - Izaskun Elezgarai
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
| | - Irantzu Rico‐Barrio
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
| | - Inmaculada Gerrikagoitia
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
| | - Nagore Puente
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
| | - Pedro Grandes
- Department of Neurosciences, Faculty of Medicine and Nursing University of the Basque Country UPV/EHU Leioa Spain
- Achucarro Basque Center for Neuroscience Science Park of the University of the Basque Country UPV/EHU Leioa Spain
- Division of Medical Sciences University of Victoria Victoria British Columbia Canada
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Held RG, Kaeser PS. ELKS active zone proteins as multitasking scaffolds for secretion. Open Biol 2019; 8:rsob.170258. [PMID: 29491150 PMCID: PMC5830537 DOI: 10.1098/rsob.170258] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 02/06/2018] [Indexed: 12/18/2022] Open
Abstract
Synaptic vesicle exocytosis relies on the tethering of release ready vesicles close to voltage-gated Ca2+ channels and specific lipids at the future site of fusion. This enables rapid and efficient neurotransmitter secretion during presynaptic depolarization by an action potential. Extensive research has revealed that this tethering is mediated by an active zone, a protein dense structure that is attached to the presynaptic plasma membrane and opposed to postsynaptic receptors. Although roles of individual active zone proteins in exocytosis are in part understood, the molecular mechanisms that hold the protein scaffold at the active zone together and link it to the presynaptic plasma membrane have remained unknown. This is largely due to redundancy within and across scaffolding protein families at the active zone. Recent studies, however, have uncovered that ELKS proteins, also called ERC, Rab6IP2 or CAST, act as active zone scaffolds redundant with RIMs. This redundancy has led to diverse synaptic phenotypes in studies of ELKS knockout mice, perhaps because different synapses rely to a variable extent on scaffolding redundancy. In this review, we first evaluate the need for presynaptic scaffolding, and we then discuss how the diverse synaptic and non-synaptic functional roles of ELKS support the hypothesis that ELKS provides molecular scaffolding for organizing vesicle traffic at the presynaptic active zone and in other cellular compartments.
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Affiliation(s)
- Richard G Held
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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7
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Hagiwara A, Kitahara Y, Grabner CP, Vogl C, Abe M, Kitta R, Ohta K, Nakamura K, Sakimura K, Moser T, Nishi A, Ohtsuka T. Cytomatrix proteins CAST and ELKS regulate retinal photoreceptor development and maintenance. J Cell Biol 2018; 217:3993-4006. [PMID: 30190286 PMCID: PMC6219712 DOI: 10.1083/jcb.201704076] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/18/2018] [Accepted: 08/03/2018] [Indexed: 01/06/2023] Open
Abstract
The retinal ribbon synapse is important for the processing of visual information. Hagiwara et al. show that the active zone proteins CAST and ELKS perform both redundant and unique functions in photoreceptors to promote the maturation, maintenance, and activity of ribbon synapses. At the presynaptic active zone (AZ), the related cytomatrix proteins CAST and ELKS organize the presynaptic release machinery. While CAST is known to regulate AZ size and neurotransmitter release, the role of ELKS and the integral system of CAST/ELKS together is poorly understood. Here, we show that CAST and ELKS have both redundant and unique roles in coordinating synaptic development, function, and maintenance of retinal photoreceptor ribbon synapses. A CAST/ELKS double knockout (dKO) mouse showed high levels of ectopic synapses and reduced responses to visual stimulation. Ectopic formation was not observed in ELKS conditional KO but progressively increased with age in CAST KO mice with higher rates in the dKO. Presynaptic calcium influx was strongly reduced in rod photoreceptors of CAST KO and dKO mice. Three-dimensional scanning EM reconstructions showed structural abnormalities in rod triads of CAST KO and dKO. Remarkably, AAV-mediated acute ELKS deletion after synapse maturation induced neurodegeneration and loss of ribbon synapses. These results suggest that CAST and ELKS work in concert to promote retinal synapse formation, transmission, and maintenance.
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Affiliation(s)
- Akari Hagiwara
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yosuke Kitahara
- Department of Pharmacology, Kurume University School of Medicine, Fukuoka, Japan
| | - Chad Paul Grabner
- Institute for Auditory Neuroscience and Inner Ear Lab, University Medical Center Göttingen, Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Christian Vogl
- Institute for Auditory Neuroscience and Inner Ear Lab, University Medical Center Göttingen, Göttingen, Germany
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Ryo Kitta
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Keisuke Ohta
- Department of Anatomy, Kurume University School of Medicine, Fukuoka, Japan
| | - Keiichiro Nakamura
- Department of Anatomy, Kurume University School of Medicine, Fukuoka, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Tobias Moser
- Institute for Auditory Neuroscience and Inner Ear Lab, University Medical Center Göttingen, Göttingen, Germany .,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
| | - Akinori Nishi
- Department of Pharmacology, Kurume University School of Medicine, Fukuoka, Japan
| | - Toshihisa Ohtsuka
- Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
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8
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Pulido C, Marty A. Quantal Fluctuations in Central Mammalian Synapses: Functional Role of Vesicular Docking Sites. Physiol Rev 2017; 97:1403-1430. [DOI: 10.1152/physrev.00032.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 04/28/2017] [Accepted: 04/29/2017] [Indexed: 12/23/2022] Open
Abstract
Quantal fluctuations are an integral part of synaptic signaling. At the frog neuromuscular junction, Bernard Katz proposed that quantal fluctuations originate at “reactive sites” where specific structures of the presynaptic membrane interact with synaptic vesicles. However, the physical nature of reactive sites has remained unclear, both at the frog neuromuscular junction and at central synapses. Many central synapses, called simple synapses, are small structures containing a single presynaptic active zone and a single postsynaptic density of receptors. Several lines of evidence indicate that simple synapses may release several synaptic vesicles in response to a single action potential. However, in some synapses at least, each release event activates a significant fraction of the postsynaptic receptors, giving rise to a sublinear relation between vesicular release and postsynaptic current. Partial receptor saturation as well as synaptic jitter gives to simple synapse signaling the appearance of a binary process. Recent investigations of simple synapses indicate that the number of released vesicles follows binomial statistics, with a maximum reflecting the number of docking sites present in the active zone. These results suggest that at central synapses, vesicular docking sites represent the reactive sites proposed by Katz. The macromolecular architecture and molecular composition of docking sites are presently investigated with novel combinations of techniques. It is proposed that variations in docking site numbers are central in defining intersynaptic variability and that docking site occupancy is a key parameter regulating short-term synaptic plasticity.
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Affiliation(s)
- Camila Pulido
- Laboratory of Brain Physiology, CNRS UMR 8118, Paris Descartes University, Paris, France
| | - Alain Marty
- Laboratory of Brain Physiology, CNRS UMR 8118, Paris Descartes University, Paris, France
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9
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Held RG, Liu C, Kaeser PS. ELKS controls the pool of readily releasable vesicles at excitatory synapses through its N-terminal coiled-coil domains. eLife 2016; 5. [PMID: 27253063 PMCID: PMC4935463 DOI: 10.7554/elife.14862] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 06/01/2016] [Indexed: 12/27/2022] Open
Abstract
In a presynaptic nerve terminal, synaptic strength is determined by the pool of readily releasable vesicles (RRP) and the probability of release (P) of each RRP vesicle. These parameters are controlled at the active zone and vary across synapses, but how such synapse specific control is achieved is not understood. ELKS proteins are enriched at vertebrate active zones and enhance P at inhibitory hippocampal synapses, but ELKS functions at excitatory synapses are not known. Studying conditional knockout mice for ELKS, we find that ELKS enhances the RRP at excitatory synapses without affecting P. Surprisingly, ELKS C-terminal sequences, which interact with RIM, are dispensable for RRP enhancement. Instead, the N-terminal ELKS coiled-coil domains that bind to Liprin-α and Bassoon are necessary to control RRP. Thus, ELKS removal has differential, synapse-specific effects on RRP and P, and our findings establish important roles for ELKS N-terminal domains in synaptic vesicle priming.
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Affiliation(s)
- Richard G Held
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, United States
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10
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Dopamine synapse is a neuroligin-2-mediated contact between dopaminergic presynaptic and GABAergic postsynaptic structures. Proc Natl Acad Sci U S A 2016; 113:4206-11. [PMID: 27035941 DOI: 10.1073/pnas.1514074113] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Midbrain dopamine neurons project densely to the striatum and form so-called dopamine synapses on medium spiny neurons (MSNs), principal neurons in the striatum. Because dopamine receptors are widely expressed away from dopamine synapses, it remains unclear how dopamine synapses are involved in dopaminergic transmission. Here we demonstrate that dopamine synapses are contacts formed between dopaminergic presynaptic and GABAergic postsynaptic structures. The presynaptic structure expressed tyrosine hydroxylase, vesicular monoamine transporter-2, and plasmalemmal dopamine transporter, which are essential for dopamine synthesis, vesicular filling, and recycling, but was below the detection threshold for molecules involving GABA synthesis and vesicular filling or for GABA itself. In contrast, the postsynaptic structure of dopamine synapses expressed GABAergic molecules, including postsynaptic adhesion molecule neuroligin-2, postsynaptic scaffolding molecule gephyrin, and GABAA receptor α1, without any specific clustering of dopamine receptors. Of these, neuroligin-2 promoted presynaptic differentiation in axons of midbrain dopamine neurons and striatal GABAergic neurons in culture. After neuroligin-2 knockdown in the striatum, a significant decrease of dopamine synapses coupled with a reciprocal increase of GABAergic synapses was observed on MSN dendrites. This finding suggests that neuroligin-2 controls striatal synapse formation by giving competitive advantage to heterologous dopamine synapses over conventional GABAergic synapses. Considering that MSN dendrites are preferential targets of dopamine synapses and express high levels of dopamine receptors, dopamine synapse formation may serve to increase the specificity and potency of dopaminergic modulation of striatal outputs by anchoring dopamine release sites to dopamine-sensing targets.
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Abstract
The first synapses transmitting visual information contain an unusual organelle, the ribbon, which is involved in the transport and priming of vesicles to be released at the active zone. The ribbon is one of many design features that allow efficient refilling of the active zone, which in turn enables graded changes in membrane potential to be transmitted using a continuous mode of neurotransmitter release. The ribbon also plays a key role in supplying vesicles for rapid and transient bursts of release that signal fast changes, such as the onset of light. We increasingly understand how the physiological properties of ribbon synapses determine basic transformations of the visual signal and, in particular, how the process of refilling the active zone regulates the gain and adaptive properties of the retinal circuit. The molecular basis of ribbon function is, however, far from clear.
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Affiliation(s)
- Leon Lagnado
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom;
| | - Frank Schmitz
- Department of Neuroanatomy, Institute for Anatomy and Cell Biology, Medical School Saarland University, Homburg/Saar, Germany;
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12
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Uversky VN. The intrinsic disorder alphabet. III. Dual personality of serine. INTRINSICALLY DISORDERED PROTEINS 2015; 3:e1027032. [PMID: 28232888 DOI: 10.1080/21690707.2015.1027032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 02/16/2015] [Accepted: 03/02/2015] [Indexed: 12/23/2022]
Abstract
Proteins are natural polypeptides consisting of 20 major amino acid residues, content and order of which in a given amino acid sequence defines the ability of a related protein to fold into unique functional state or to stay intrinsically disordered. Amino acid sequences code for both foldable (ordered) proteins/domains and for intrinsically disordered proteins (IDPs) and IDP regions (IDPRs), but these sequence codes are dramatically different. This difference starts with a very general property of the corresponding amino acid sequences, namely, their compositions. IDPs/IDPRs are enriched in specific disorder-promoting residues, whereas amino acid sequences of ordered proteins/domains typically contain more order-promoting residues. Therefore, the relative abundances of various amino acids in ordered and disordered proteins can be used to scale amino acids according to their disorder promoting potentials. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and represents serine, which is the third most disorder-promoting residue. Similar to previous publications, this review represents some physico-chemical properties of serine and the roles of this residue in structures and functions of ordered proteins, describes major posttranslational modifications tailored to serine, and finally gives an overview of roles of serine in structure and functions of intrinsically disordered proteins.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer Research Institute; Morsani College of Medicine, University of South Florida; Tampa, FL USA; Biology Department; Faculty of Science, King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia; Institute for Biological Instrumentation, Russian Academy of Sciences; Pushchino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins; Institute of Cytology, Russian Academy of Sciences; St. Petersburg, Russia
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13
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Laßek M, Weingarten J, Volknandt W. The synaptic proteome. Cell Tissue Res 2014; 359:255-65. [PMID: 25038742 DOI: 10.1007/s00441-014-1943-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/04/2014] [Indexed: 11/29/2022]
Abstract
Synapses are focal hot spots for signal transduction and plasticity in the brain. A synapse comprises an axon terminus, the presynapse, the synaptic cleft containing extracellular matrix proteins as well as adhesion molecules, and the postsynaptic density as target structure for chemical signaling. The proteomes of the presynaptic and postsynaptic active zones control neurotransmitter release and perception. These tasks demand short- and long-term structural and functional dynamics of the synapse mediated by its proteinaceous inventory. This review addresses subcellular fractionation protocols and the related proteomic approaches to the various synaptic subcompartments with an emphasis on the presynaptic active zone (PAZ). Furthermore, it discusses major constituents of the PAZ including the amyloid precursor protein family members. Numerous proteins regulating the rearrangement of the cytoskeleton are indicative of the functional and structural dynamics of the pre- and postsynapse. The identification of protein candidates of the synapse provides the basis for further analyzing the interaction of synaptic proteins with their targets, and the effect of their deletion opens novel insights into the functional role of these proteins in neuronal communication. The knowledge of the molecular interactome is also a prerequisite for understanding numerous neurodegenerative diseases.
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Affiliation(s)
- Melanie Laßek
- Molecular and Cellular Neurobiology, Goethe University, Frankfurt, Germany
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14
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Laßek M, Weingarten J, Volknandt W. The Proteome of the Murine Presynaptic Active Zone. Proteomes 2014; 2:243-257. [PMID: 28250380 PMCID: PMC5302740 DOI: 10.3390/proteomes2020243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/09/2014] [Accepted: 04/21/2014] [Indexed: 01/09/2023] Open
Abstract
The proteome of the presynaptic active zone controls neurotransmitter release and the short- and long-term structural and functional dynamics of the nerve terminal. The proteinaceous inventory of the presynaptic active zone has recently been reported. This review will evaluate the subcellular fractionation protocols and the proteomic approaches employed. A breakthrough for the identification of the proteome of the presynaptic active zone was the successful employment of antibodies directed against a cytosolic epitope of membrane integral synaptic vesicle proteins for the immunopurification of synaptic vesicles docked to the presynaptic plasma membrane. Combining immunopurification and subsequent analytical mass spectrometry, hundreds of proteins, including synaptic vesicle proteins, components of the presynaptic fusion and retrieval machinery, proteins involved in intracellular and extracellular signaling and a large variety of adhesion molecules, were identified. Numerous proteins regulating the rearrangement of the cytoskeleton are indicative of the functional and structural dynamics of the presynapse. This review will critically discuss both the experimental approaches and prominent protein candidates identified. Many proteins have not previously been assigned to the presynaptic release sites and may be directly involved in the short- and long-term structural modulation of the presynaptic compartment. The identification of proteinaceous constituents of the presynaptic active zone provides the basis for further analyzing the interaction of presynaptic proteins with their targets and opens novel insights into the functional role of these proteins in neuronal communication.
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Affiliation(s)
- Melanie Laßek
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
| | - Jens Weingarten
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
| | - Walter Volknandt
- Institute for Cell Biology and Neuroscience, Department Molecular and Cellular Neurobiology, Max von Laue Str. 13, 60438 Frankfurt am Main, Germany.
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