1
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Su M, Xuan E, Sun X, Pan G, Li D, Zheng H, Zhang YW, Li Y. Synaptic adhesion molecule protocadherin-γC5 mediates β-amyloid-induced neuronal hyperactivity and cognitive deficits in Alzheimer's disease. J Neurochem 2024; 168:1060-1079. [PMID: 38308496 DOI: 10.1111/jnc.16066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 02/04/2024]
Abstract
Neuronal hyperactivity induced by β-amyloid (Aβ) is an early pathological feature in Alzheimer's disease (AD) and contributes to cognitive decline in AD progression. However, the underlying mechanisms are still unclear. Here, we revealed that Aβ increased the expression level of synaptic adhesion molecule protocadherin-γC5 (Pcdh-γC5) in a Ca2+-dependent manner, associated with aberrant elevation of synapses in both Aβ-treated neurons in vitro and the cortex of APP/PS1 mice in vivo. By using Pcdhgc5 gene knockout mice, we demonstrated the critical function of Pcdh-γC5 in regulating neuronal synapse formation, synaptic transmission, and cognition. To further investigate the role of Pcdh-γC5 in AD pathogenesis, the aberrantly enhanced expression of Pcdh-γC5 in the brain of APP/PS1 mice was knocked down by shRNA. Downregulation of Pcdh-γC5 efficiently rescued neuronal hyperactivity and impaired cognition in APP/PS1 mice. Our findings revealed the pathophysiological role of Pcdh-γC5 in mediating Aβ-induced neuronal hyperactivity and cognitive deficits in AD and identified a novel mechanism underlying AD pathogenesis.
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Affiliation(s)
- Min Su
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Erying Xuan
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Xiangyi Sun
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Gaojie Pan
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Dandan Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, Fujian, China
- Shenzhen Research Institute of Xiamen University, Shenzhen, Guangdong, China
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2
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Verpoort B, de Wit J. Cell Adhesion Molecule Signaling at the Synapse: Beyond the Scaffold. Cold Spring Harb Perspect Biol 2024; 16:a041501. [PMID: 38316556 PMCID: PMC11065171 DOI: 10.1101/cshperspect.a041501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Synapses are specialized intercellular junctions connecting pre- and postsynaptic neurons into functional neural circuits. Synaptic cell adhesion molecules (CAMs) constitute key players in synapse development that engage in homo- or heterophilic interactions across the synaptic cleft. Decades of research have identified numerous synaptic CAMs, mapped their trans-synaptic interactions, and determined their role in orchestrating synaptic connectivity. However, surprisingly little is known about the molecular mechanisms that translate trans-synaptic adhesion into the assembly of pre- and postsynaptic compartments. Here, we provide an overview of the intracellular signaling pathways that are engaged by synaptic CAMs and highlight outstanding issues to be addressed in future work.
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Affiliation(s)
- Ben Verpoort
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
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3
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Zhu YJ, Deng CY, Fan L, Wang YQ, Zhou H, Xu HT. Combinatorial expression of γ-protocadherins regulates synaptic connectivity in the mouse neocortex. eLife 2024; 12:RP89532. [PMID: 38470230 DOI: 10.7554/elife.89532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024] Open
Abstract
In the process of synaptic formation, neurons must not only adhere to specific principles when selecting synaptic partners but also possess mechanisms to avoid undesirable connections. Yet, the strategies employed to prevent unwarranted associations have remained largely unknown. In our study, we have identified the pivotal role of combinatorial clustered protocadherin gamma (γ-PCDH) expression in orchestrating synaptic connectivity in the mouse neocortex. Through 5' end single-cell sequencing, we unveiled the intricate combinatorial expression patterns of γ-PCDH variable isoforms within neocortical neurons. Furthermore, our whole-cell patch-clamp recordings demonstrated that as the similarity in this combinatorial pattern among neurons increased, their synaptic connectivity decreased. Our findings elucidate a sophisticated molecular mechanism governing the construction of neural networks in the mouse neocortex.
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Affiliation(s)
- Yi-Jun Zhu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Cai-Yun Deng
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Liu Fan
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Ya-Qian Wang
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Hui Zhou
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Hua-Tai Xu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
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4
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Hanes CM, Mah KM, Steffen DM, Marcucci CG, Fuller LC, Burgess RW, Garrett AM, Weiner JA. A C-terminal motif containing a PKC phosphorylation site regulates γ-Protocadherin-mediated dendrite arborization in the cerebral cortex in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577214. [PMID: 38328061 PMCID: PMC10849722 DOI: 10.1101/2024.01.25.577214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The Pcdhg gene cluster encodes 22 γ-Protocadherin (γ-Pcdh) cell adhesion molecules that critically regulate multiple aspects of neural development, including neuronal survival, dendritic and axonal arborization, and synapse formation and maturation. Each γ-Pcdh isoform has unique protein domains-a homophilically-interacting extracellular domain and a juxtamembrane cytoplasmic domain-as well as a C-terminal cytoplasmic domain shared by all isoforms. The extent to which isoform-specific vs. shared domains regulate distinct γ-Pcdh functions remains incompletely understood. Our previous in vitro studies identified PKC phosphorylation of a serine residue within a shared C-terminal motif as a mechanism through which γ-Pcdh promotion of dendrite arborization via MARCKS is abrogated. Here, we used CRISPR/Cas9 genome editing to generate two new mouse lines expressing only non-phosphorylatable γ-Pcdhs, due either to a serine-to-alanine mutation (PcdhgS/A) or to a 15-amino acid C-terminal deletion resulting from insertion of an early stop codon (PcdhgCTD). Both lines are viable and fertile, and the density and maturation of dendritic spines remains unchanged in both PcdhgS/A and PcdhgCTD cortex. Dendrite arborization of cortical pyramidal neurons, however, is significantly increased in both lines, as are levels of active MARCKS. Intriguingly, despite having significantly reduced levels of γ-Pcdh proteins, the PcdhgCTD mutation yields the strongest phenotype, with even heterozygous mutants exhibiting increased arborization. The present study confirms that phosphorylation of a shared C-terminal motif is a key γ-Pcdh negative regulation point, and contributes to a converging understanding of γ-Pcdh family function in which distinct roles are played by both individual isoforms and discrete protein domains.
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Affiliation(s)
- Camille M. Hanes
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | - Kar Men Mah
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | - David M. Steffen
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | - Charles G. Marcucci
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | - Leah C. Fuller
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | | | - Andrew M. Garrett
- Department of Pharmacology and Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University, Detroit, MI 48202
| | - Joshua A. Weiner
- Department of Biology, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
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5
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Connor SA, Siddiqui TJ. Synapse organizers as molecular codes for synaptic plasticity. Trends Neurosci 2023; 46:971-985. [PMID: 37652840 DOI: 10.1016/j.tins.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/13/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Synapse organizing proteins are multifaceted molecules that coordinate the complex processes of brain development and plasticity at the level of individual synapses. Their importance is demonstrated by the major brain disorders that emerge when their function is compromised. The mechanisms whereby the various families of organizers govern synapses are diverse, but converge on the structure, function, and plasticity of synapses. Therefore, synapse organizers regulate how synapses adapt to ongoing activity, a process central for determining the developmental trajectory of the brain and critical to all forms of cognition. Here, we explore how synapse organizers set the conditions for synaptic plasticity and the associated molecular events, which eventually link to behavioral features of neurodevelopmental and neuropsychiatric disorders. We also propose central questions on how synapse organizers influence network function through integrating nanoscale and circuit-level organization of the brain.
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Affiliation(s)
- Steven A Connor
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Tabrez J Siddiqui
- PrairieNeuro Research Centre, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, MB R3E 0Z3, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; The Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada; Program in Biomedical Engineering, University of Manitoba, Winnipeg, MB, Canada.
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6
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Darwish M, Ito M, Iijima Y, Takase A, Ayukawa N, Suzuki S, Tanaka M, Komori K, Kaida D, Iijima T. Neuronal SAM68 differentially regulates alternative last exon splicing and ensures proper synapse development and function. J Biol Chem 2023; 299:105168. [PMID: 37595869 PMCID: PMC10562862 DOI: 10.1016/j.jbc.2023.105168] [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: 07/02/2023] [Revised: 07/30/2023] [Accepted: 08/07/2023] [Indexed: 08/20/2023] Open
Abstract
Alternative splicing in the 3'UTR of mammalian genes plays a crucial role in diverse biological processes, including cell differentiation and development. SAM68 is a key splicing regulator that controls the diversity of 3'UTR isoforms through alternative last exon (ALE) selection. However, the tissue/cell type-specific mechanisms underlying the splicing control at the 3' end and its functional significance remain unclear. Here, we show that SAM68 regulates ALE splicing in a dose-dependent manner and the neuronal splicing is differentially regulated depending on the characteristics of the target transcript. Specifically, we found that SAM68 regulates interleukin-1 receptor-associated protein splicing through the interaction with U1 small nuclear ribonucleoprotein. In contrast, the ALE splicing of protocadherin-15 (Pcdh15), a gene implicated in several neuropsychiatric disorders, is independent of U1 small nuclear ribonucleoprotein but modulated by the calcium/calmodulin-dependent protein kinase signaling pathway. We found that the aberrant ALE selection of Pcdh15 led to a conversion from a membrane-bound to a soluble isoform and consequently disrupted its localization into excitatory and inhibitory synapses. Notably, the neuronal expression of the soluble form of PCDH15 preferentially affected the number of inhibitory synapses. Moreover, the soluble form of PCDH15 interacted physically with α-neurexins and further disrupted neuroligin-2-induced inhibitory synapses in artificial synapse formation assays. Our findings provide novel insights into the role of neuron-specific alternative 3'UTR isoform selections in synapse development.
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Affiliation(s)
- Mohamed Darwish
- Division of Basic Medical Science and Molecular Medicine, Department of Molecular Life Science, School of Medicine, Tokai University, Kanagawa, Japan; Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Masatoshi Ito
- The Support Center for Medical Research and Education, Tokai University, Kanagawa, Japan
| | - Yoko Iijima
- Division of Basic Medical Science and Molecular Medicine, Department of Molecular Life Science, School of Medicine, Tokai University, Kanagawa, Japan; Tokai University Institute of Innovative Science and Technology, Isehara, Kanagawa, Japan
| | - Akinori Takase
- The Support Center for Medical Research and Education, Tokai University, Kanagawa, Japan
| | - Noriko Ayukawa
- Tokai University Institute of Innovative Science and Technology, Isehara, Kanagawa, Japan
| | - Satoko Suzuki
- Tokai University Institute of Innovative Science and Technology, Isehara, Kanagawa, Japan
| | - Masami Tanaka
- Tokai University Institute of Innovative Science and Technology, Isehara, Kanagawa, Japan
| | - Kanae Komori
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Daisuke Kaida
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takatoshi Iijima
- Division of Basic Medical Science and Molecular Medicine, Department of Molecular Life Science, School of Medicine, Tokai University, Kanagawa, Japan; Tokai University Institute of Innovative Science and Technology, Isehara, Kanagawa, Japan.
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7
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Hoshino N, Kanadome T, Takasugi T, Itoh M, Kaneko R, Inoue YU, Inoue T, Hirabayashi T, Watanabe M, Matsuda T, Nagai T, Tarusawa E, Yagi T. Visualization of trans homophilic interaction of clustered protocadherin in neurons. Proc Natl Acad Sci U S A 2023; 120:e2301003120. [PMID: 37695902 PMCID: PMC10515168 DOI: 10.1073/pnas.2301003120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/20/2023] [Indexed: 09/13/2023] Open
Abstract
Clustered protocadherin (Pcdh) functions as a cell recognition molecule through the homophilic interaction in the central nervous system. However, its interactions have not yet been visualized in neurons. We previously reported PcdhγB2-Förster resonance energy transfer (FRET) probes to be applicable only to cell lines. Herein, we designed γB2-FRET probes by fusing FRET donor and acceptor fluorescent proteins to a single γB2 molecule and succeeded in visualizing γB2 homophilic interaction in cultured hippocampal neurons. The γB2-FRET probe localized in the soma and neurites, and FRET signals, which were observed at contact sites between neurites, eliminated by ethylene glycol tetraacetic acid (EGTA) addition. Live imaging revealed that the FRET-negative γB2 signals rapidly moved along neurites and soma, whereas the FRET-positive signals remained in place. We observed that the γB2 proteins at synapses rarely interact homophilically. The γB2-FRET probe might allow us to elucidate the function of the homophilic interaction and the cell recognition mechanism.
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Affiliation(s)
- Natsumi Hoshino
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Takashi Kanadome
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama332-0012, Japan
| | - Tomomi Takasugi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Mizuho Itoh
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Ryosuke Kaneko
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Yukiko U. Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo187-8501, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo187-8501, Japan
| | - Takahiro Hirabayashi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
- Clinical Medicine Research Laboratory, Shonan University of Medical Sciences, Yokohama244-0806, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido060-8638, Japan
| | - Tomoki Matsuda
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
| | - Takeharu Nagai
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
| | - Etsuko Tarusawa
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
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8
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Ptashnik A, LaMassa N, Mambetalieva A, Schnall E, Bucaro M, Phillips GR. Ubiquitination of the protocadherin-γA3 variable cytoplasmic domain modulates cell-cell interaction. Front Cell Dev Biol 2023; 11:1261048. [PMID: 37791076 PMCID: PMC10544333 DOI: 10.3389/fcell.2023.1261048] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023] Open
Abstract
The family of ∼60 clustered protocadherins (Pcdhs) are cell adhesion molecules encoded by a genomic locus that regulates expression of distinct combinations of isoforms in individual neurons resulting in what is thought to be a neural surface "barcode" which mediates same-cell interactions of dendrites, as well as interactions with other cells in the environment. Pcdh mediated same-cell dendrite interactions were shown to result in avoidance while interactions between different cells through Pcdhs, such as between neurons and astrocytes, appear to be stable. The cell biological mechanism of the consequences of Pcdh based adhesion is not well understood although various signaling pathways have been recently uncovered. A still unidentified cytoplasmic regulatory mechanism might contribute to a "switch" between avoidance and adhesion. We have proposed that endocytosis and intracellular trafficking could be part of such a switch. Here we use "stub" constructs consisting of the proximal cytoplasmic domain (lacking the constant carboxy-terminal domain spliced to all Pcdh-γs) of one Pcdh, Pcdh-γA3, to study trafficking. We found that the stub construct traffics primarily to Rab7 positive endosomes very similarly to the full length molecule and deletion of a substantial portion of the carboxy-terminus of the stub eliminates this trafficking. The intact stub was found to be ubiquitinated while the deletion was not and this ubiquitination was found to be at non-lysine sites. Further deletion mapping of the residues required for ubiquitination identified potential serine phosphorylation sites, conserved among Pcdh-γAs, that can reduce ubiquitination when pseudophosphorylated and increase surface expression. These results suggest Pcdh-γA ubiquitination can influence surface expression which may modulate adhesive activity during neural development.
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Affiliation(s)
- Albert Ptashnik
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
| | - Nicole LaMassa
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
| | - Aliya Mambetalieva
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Emily Schnall
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Mike Bucaro
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Greg R. Phillips
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
- Center for Developmental Neuroscience, College of Staten Island, City University of New York, New York, NY, United States
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9
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Kanadome T, Hoshino N, Nagai T, Yagi T, Matsuda T. Visualization of trans-interactions of a protocadherin-α between processes originating from single neurons. iScience 2023; 26:107238. [PMID: 37534169 PMCID: PMC10392085 DOI: 10.1016/j.isci.2023.107238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/15/2023] [Accepted: 06/26/2023] [Indexed: 08/04/2023] Open
Abstract
Clustered protocadherin (Pcdh), a cell adhesion protein, is involved in the self-recognition and non-self-discrimination of neurons by conferring diversity on the cell surface. Although the roles of Pcdh in neurons have been elucidated, it has been challenging to visualize its adhesion activity in neurons, which is a molecular function of Pcdh. Here, we present fluorescent indicators, named IPADs, which visualize the interaction of protocadherin-α4 isoform (α4). IPADs successfully visualize not only homophilic α4 trans-interactions, but also combinatorial homophilic interactions between cells. The reversible nature of IPADs overcomes a drawback of the split-GFP technique and allows for monitoring the dissociation of α4 trans-interactions. Specially designed IPADs for self-recognition are able to monitor the formation and disruption of α4 trans-interactions between processes originating from the same neurons. We expect that IPADs will be useful tools for obtaining spatiotemporal information on Pcdh interactions in neuronal self-recognition and non-self-discrimination processes.
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Affiliation(s)
- Takashi Kanadome
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
- Department of Biomolecular Science and Engineering, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Japan
| | - Natsumi Hoshino
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Takeharu Nagai
- Department of Biomolecular Science and Engineering, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Tomoki Matsuda
- Department of Biomolecular Science and Engineering, SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Japan
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10
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Jin J, Ralls S, Wu E, Wolf G, Sun MA, Springer DA, Cosby RL, Senft AD, Macfarlan TS. CTCF barrier breaking by ZFP661 promotes protocadherin diversity in mammalian brains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539838. [PMID: 39185186 PMCID: PMC11343191 DOI: 10.1101/2023.05.08.539838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Mammalian brains are larger and more densely packed with neurons than reptiles, but the genetic mechanisms underlying the increased connection complexity amongst neurons are unclear. The expression diversity of clustered protocadherins (Pcdhs), which is controlled by CTCF and cohesin, is crucial for proper dendritic arborization and cortical connectivity in vertebrates. Here, we identify a highly-conserved and mammalian-restricted protein, ZFP661, that binds antagonistically at CTCF barriers at the Pcdh locus, preventing CTCF from trapping cohesin. ZFP661 balances the usage of Pcdh isoforms and increases Pcdh expression diversity. Loss of Zfp661 causes cortical dendritic arborization defects and autism-like social deficits in mice. Our study reveals both a novel mechanism that regulates the trapping of cohesin by CTCF and a mammalian adaptation that promoted Pcdh expression diversity to accompany the expanded mammalian brain.
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Affiliation(s)
- Jinpu Jin
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sherry Ralls
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elaine Wu
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gernot Wolf
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ming-An Sun
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Danielle A. Springer
- The National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Rachel L. Cosby
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anna D. Senft
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Todd S. Macfarlan
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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11
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Steffen DM, Hanes CM, Mah KM, Valiño Ramos P, Bosch PJ, Hinz DC, Radley JJ, Burgess RW, Garrett AM, Weiner JA. A Unique Role for Protocadherin γC3 in Promoting Dendrite Arborization through an Axin1-Dependent Mechanism. J Neurosci 2023; 43:918-935. [PMID: 36604170 PMCID: PMC9908324 DOI: 10.1523/jneurosci.0729-22.2022] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/30/2022] [Accepted: 12/24/2022] [Indexed: 01/06/2023] Open
Abstract
The establishment of a functional cerebral cortex depends on the proper execution of multiple developmental steps, culminating in dendritic and axonal outgrowth and the formation and maturation of synaptic connections. Dysregulation of these processes can result in improper neuronal connectivity, including that associated with various neurodevelopmental disorders. The γ-Protocadherins (γ-Pcdhs), a family of 22 distinct cell adhesion molecules that share a C-terminal cytoplasmic domain, are involved in multiple aspects of neurodevelopment including neuronal survival, dendrite arborization, and synapse development. The extent to which individual γ-Pcdh family members play unique versus common roles remains unclear. We demonstrated previously that the γ-Pcdh-C3 isoform (γC3), via its unique "variable" cytoplasmic domain (VCD), interacts in cultured cells with Axin1, a Wnt-pathway scaffold protein that regulates the differentiation and morphology of neurons. Here, we confirm that γC3 and Axin1 interact in the cortex in vivo and show that both male and female mice specifically lacking γC3 exhibit disrupted Axin1 localization to synaptic fractions, without obvious changes in dendritic spine density or morphology. However, both male and female γC3 knock-out mice exhibit severely decreased dendritic complexity of cortical pyramidal neurons that is not observed in mouse lines lacking several other γ-Pcdh isoforms. Combining knock-out with rescue constructs in cultured cortical neurons pooled from both male and female mice, we show that γC3 promotes dendritic arborization through an Axin1-dependent mechanism mediated through its VCD. Together, these data identify a novel mechanism through which γC3 uniquely regulates the formation of cortical circuitry.SIGNIFICANCE STATEMENT The complexity of a neuron's dendritic arbor is critical for its function. We showed previously that the γ-Protocadherin (γ-Pcdh) family of 22 cell adhesion molecules promotes arborization during development; it remained unclear whether individual family members played unique roles. Here, we show that one γ-Pcdh isoform, γC3, interacts in the brain with Axin1, a scaffolding protein known to influence dendrite development. A CRISPR/Cas9-generated mutant mouse line lacking γC3 (but not lines lacking other γ-Pcdhs) exhibits severely reduced dendritic complexity of cerebral cortex neurons. Using cultured γC3 knock-out neurons and a variety of rescue constructs, we confirm that the γC3 cytoplasmic domain promotes arborization through an Axin1-dependent mechanism. Thus, γ-Pcdh isoforms are not interchangeable, but rather can play unique neurodevelopmental roles.
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Affiliation(s)
- David M Steffen
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
| | - Camille M Hanes
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
| | - Kar Men Mah
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
| | - Paula Valiño Ramos
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
| | - Peter J Bosch
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
| | - Dalton C Hinz
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Psychological and Brain Sciences, Program in Neuroscience, Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242
| | - Jason J Radley
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Psychological and Brain Sciences, Program in Neuroscience, Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242
| | | | - Andrew M Garrett
- Department of Pharmacology and Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University, Detroit, Michigan 48202
| | - Joshua A Weiner
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, Iowa 52242
- Department of Biology, The University of Iowa, Iowa City, Iowa 52242
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12
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Pohl TT, Hörnberg H. Neuroligins in neurodevelopmental conditions: how mouse models of de novo mutations can help us link synaptic function to social behavior. Neuronal Signal 2022; 6:NS20210030. [PMID: 35601025 PMCID: PMC9093077 DOI: 10.1042/ns20210030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 04/08/2022] [Accepted: 04/20/2022] [Indexed: 11/19/2022] Open
Abstract
Neurodevelopmental conditions (or neurodevelopmental disorders, NDDs) are highly heterogeneous with overlapping characteristics and shared genetic etiology. The large symptom variability and etiological heterogeneity have made it challenging to understand the biological mechanisms underpinning NDDs. To accommodate this individual variability, one approach is to move away from diagnostic criteria and focus on distinct dimensions with relevance to multiple NDDs. This domain approach is well suited to preclinical research, where genetically modified animal models can be used to link genetic variability to neurobiological mechanisms and behavioral traits. Genetic factors associated with NDDs can be grouped functionally into common biological pathways, with one prominent functional group being genes associated with the synapse. These include the neuroligins (Nlgns), a family of postsynaptic transmembrane proteins that are key modulators of synaptic function. Here, we review how research using Nlgn mouse models has provided insight into how synaptic proteins contribute to behavioral traits associated with NDDs. We focus on how mutations in different Nlgns affect social behaviors, as differences in social interaction and communication are a common feature of most NDDs. Importantly, mice carrying distinct mutations in Nlgns share some neurobiological and behavioral phenotypes with other synaptic gene mutations. Comparing the functional implications of mutations in multiple synaptic proteins is a first step towards identifying convergent neurobiological pathways in multiple brain regions and circuits.
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Affiliation(s)
- Tobias T. Pohl
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Straße 10, Berlin 13125, Germany
| | - Hanna Hörnberg
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Straße 10, Berlin 13125, Germany
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13
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Neel BL, Nisler CR, Walujkar S, Araya-Secchi R, Sotomayor M. Collective mechanical responses of cadherin-based adhesive junctions as predicted by simulations. Biophys J 2022; 121:991-1012. [PMID: 35150618 PMCID: PMC8943820 DOI: 10.1016/j.bpj.2022.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/02/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
Abstract
Cadherin-based adherens junctions and desmosomes help stabilize cell-cell contacts with additional function in mechano-signaling, while clustered protocadherin junctions are responsible for directing neuronal circuits assembly. Structural models for adherens junctions formed by epithelial cadherin (CDH1) proteins indicate that their long, curved ectodomains arrange to form a periodic, two-dimensional lattice stabilized by tip-to-tip trans interactions (across junction) and lateral cis contacts. Less is known about the exact architecture of desmosomes, but desmoglein (DSG) and desmocollin (DSC) cadherin proteins are also thought to form ordered junctions. In contrast, clustered protocadherin (PCDH)-based cell-cell contacts in neuronal tissues are thought to be responsible for self-recognition and avoidance, and structural models for clustered PCDH junctions show a linear arrangement in which their long and straight ectodomains form antiparallel overlapped trans complexes. Here, we report all-atom molecular dynamics simulations testing the mechanics of minimalistic adhesive junctions formed by CDH1, DSG2 coupled to DSC1, and PCDHγB4, with systems encompassing up to 3.7 million atoms. Simulations generally predict a favored shearing pathway for the adherens junction model and a two-phased elastic response to tensile forces for the adhesive adherens junction and the desmosome models. Complexes within these junctions first unbend at low tensile force and then become stiff to unbind without unfolding. However, cis interactions in both the CDH1 and DSG2-DSC1 systems dictate varied mechanical responses of individual dimers within the junctions. Conversely, the clustered protocadherin PCDHγB4 junction lacks a distinct two-phased elastic response. Instead, applied tensile force strains trans interactions directly, as there is little unbending of monomers within the junction. Transient intermediates, influenced by new cis interactions, are observed after the main rupture event. We suggest that these collective, complex mechanical responses mediated by cis contacts facilitate distinct functions in robust cell-cell adhesion for classical cadherins and in self-avoidance signaling for clustered PCDHs.
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Affiliation(s)
- Brandon L Neel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Collin R Nisler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Facultad de Ingenieria y Tecnologia, Universidad San Sebastian, Santiago, Chile
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio.
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14
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Goodman KM, Katsamba PS, Rubinstein R, Ahlsén G, Bahna F, Mannepalli S, Dan H, Sampogna RV, Shapiro L, Honig B. How clustered protocadherin binding specificity is tuned for neuronal self-/nonself-recognition. eLife 2022; 11:e72416. [PMID: 35253643 PMCID: PMC8901172 DOI: 10.7554/elife.72416] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/26/2022] [Indexed: 12/30/2022] Open
Abstract
The stochastic expression of fewer than 60 clustered protocadherin (cPcdh) isoforms provides diverse identities to individual vertebrate neurons and a molecular basis for self-/nonself-discrimination. cPcdhs form chains mediated by alternating cis and trans interactions between apposed membranes, which has been suggested to signal self-recognition. Such a mechanism requires that cPcdh cis dimers form promiscuously to generate diverse recognition units, and that trans interactions have precise specificity so that isoform mismatches terminate chain growth. However, the extent to which cPcdh interactions fulfill these requirements has not been definitively demonstrated. Here, we report biophysical experiments showing that cPcdh cis interactions are promiscuous, but with preferences favoring formation of heterologous cis dimers. Trans homophilic interactions are remarkably precise, with no evidence for heterophilic interactions between different isoforms. A new C-type cPcdh crystal structure and mutagenesis data help to explain these observations. Overall, the interaction characteristics we report for cPcdhs help explain their function in neuronal self-/nonself-discrimination.
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Affiliation(s)
- Kerry Marie Goodman
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Phinikoula S Katsamba
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Rotem Rubinstein
- School of Neurobiology, Biochemistry and Biophysics, Tel Aviv UniversityTel AvivIsrael
- Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - Göran Ahlsén
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Fabiana Bahna
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Seetha Mannepalli
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Hanbin Dan
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
| | - Rosemary V Sampogna
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
| | - Lawrence Shapiro
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
- Department of Biochemistry and Molecular Biophysics, Columbia UniversityNew YorkUnited States
| | - Barry Honig
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
- Department of Biochemistry and Molecular Biophysics, Columbia UniversityNew YorkUnited States
- Department of Systems Biology, Columbia UniversityNew YorkUnited States
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15
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Development of FRET-based indicators for visualizing homophilic trans interaction of a clustered protocadherin. Sci Rep 2021; 11:22237. [PMID: 34782670 PMCID: PMC8593154 DOI: 10.1038/s41598-021-01481-2] [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: 08/24/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022] Open
Abstract
Clustered protocadherins (Pcdhs), which are cell adhesion molecules, play a fundamental role in self-recognition and non-self-discrimination by conferring diversity on the cell surface. Although systematic cell-based aggregation assays provide information regarding the binding properties of Pcdhs, direct visualization of Pcdh trans interactions across cells remains challenging. Here, we present Förster resonance energy transfer (FRET)-based indicators for directly visualizing Pcdh trans interactions. We developed the indicators by individually inserting FRET donor and acceptor fluorescent proteins (FPs) into the ectodomain of Pcdh molecules. They enabled successful visualization of specific trans interactions of Pcdh and revealed that the Pcdh trans interaction is highly sensitive to changes in extracellular Ca2+ levels. We expect that FRET-based indicators for visualizing Pcdh trans interactions will provide a new approach for investigating the roles of Pcdh in self-recognition and non-self-discrimination processes.
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16
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Tan CX, Eroglu C. Cell adhesion molecules regulating astrocyte-neuron interactions. Curr Opin Neurobiol 2021; 69:170-177. [PMID: 33957433 PMCID: PMC8387342 DOI: 10.1016/j.conb.2021.03.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/15/2022]
Abstract
A tripartite synapse comprises a neuronal presynaptic axon and a postsynaptic dendrite, which are closely ensheathed by a perisynaptic astrocyte process. Through their structural and functional association with thousands of neuronal synapses, astrocytes regulate synapse formation and function. Recent work revealed a diverse range of cell adhesion-based mechanisms that mediate astrocyte-synapse interactions at tripartite synapses. Here, we will review some of these findings unveiling a highly dynamic bidirectional signaling between astrocytes and synapses, which orchestrates astrocyte morphological maturation and synapse development. Moreover, we will discuss the roles of these newly discovered molecular pathways in brain physiology and function both in health and disease.
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Affiliation(s)
- Christabel X Tan
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA; Duke Institute for Brain Sciences, Durham, NC, 27710, USA; Regeneration Next Initiative, Duke University, Durham, NC, 27710, USA.
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