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Adel SS, Pranske ZJ, Kowalski TF, Kanzler N, Ray R, Carmona C, Paradis S. Plexin-B1 and Plexin-B2 play non-redundant roles in GABAergic synapse formation. Mol Cell Neurosci 2024; 128:103920. [PMID: 38331011 PMCID: PMC11046529 DOI: 10.1016/j.mcn.2024.103920] [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: 10/23/2023] [Revised: 01/24/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
Synapse formation in the mammalian brain is a complex and dynamic process requiring coordinated function of dozens of molecular families such as cell adhesion molecules (CAMs) and ligand-receptor pairs (Ephs/Ephrins, Neuroligins/Neurexins, Semaphorins/Plexins). Due to the large number of molecular players and possible functional redundancies within gene families, it is challenging to determine the precise synaptogenic roles of individual molecules, which is key to understanding the consequences of mutations in these genes for brain function. Furthermore, few molecules are known to exclusively regulate either GABAergic or glutamatergic synapses, and cell and molecular mechanisms underlying GABAergic synapse formation in particular are not thoroughly understood. We previously demonstrated that Semaphorin-4D (Sema4D) regulates GABAergic synapse development in the mammalian hippocampus while having no effect on glutamatergic synapse development, and this effect occurs through binding to its high affinity receptor, Plexin-B1. In addition, we demonstrated that RNAi-mediated Plexin-B2 knock-down decreases GABAergic synapse density suggesting that both receptors function in this process. Here, we perform a structure-function study of the Plexin-B1 and Plexin-B2 receptors to identify the protein domains in each receptor which are required for its synaptogenic function. Further, we examine whether Plexin-B2 is required in the presynaptic neuron, the postsynaptic neuron, or both to regulate GABAergic synapse formation. Our data reveal that Plexin-B1 and Plexin-B2 function non-redundantly to regulate GABAergic synapse formation and suggest that the transmembrane domain may underlie functional distinctions. We also provide evidence that Plexin-B2 expression in presynaptic GABAergic interneurons, as well as postsynaptic pyramidal cells, regulates GABAergic synapse formation in hippocampus. These findings lay the groundwork for future investigations into the precise signaling pathways required for synapse formation downstream of Plexin-B receptor signaling.
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Affiliation(s)
- Susannah S Adel
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Zachary J Pranske
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Tess F Kowalski
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Nicole Kanzler
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Roshni Ray
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Catherine Carmona
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America
| | - Suzanne Paradis
- Department of Biology, Brandeis University, Waltham, MA 02454, United States of America.
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2
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Adel SS, Pranske ZJ, Kowalski TF, Kanzler N, Ray R, Carmona C, Paradis S. Plexin-B1 and Plexin-B2 play non-redundant roles in GABAergic synapse formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.27.564428. [PMID: 37961237 PMCID: PMC10634878 DOI: 10.1101/2023.10.27.564428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Synapse formation in the mammalian brain is a complex and dynamic process requiring coordinated function of dozens of molecular families such as cell adhesion molecules (CAMs) and ligand-receptor pairs (Ephs/Ephrins, Neuroligins/Neurexins, Semaphorins/Plexins). Due to the large number of molecular players and possible functional redundancies within gene families, it is challenging to determine the precise synaptogenic roles of individual molecules, which is key to understanding the consequences of mutations in these genes for brain function. Furthermore, few molecules are known to exclusively regulate either GABAergic or glutamatergic synapses, and cell and molecular mechanisms underlying GABAergic synapse formation in particular are not thoroughly understood. However, we previously demonstrated that Semaphorin-4D (Sema4D) regulates GABAergic synapse development in the mammalian hippocampus while having no effect on glutamatergic synapse development, and this effect occurs through binding to its high affinity receptor, Plexin-B1. Furthermore, Plexin-B2 contributes to GABAergic synapse formation as well but is not required for GABAergic synapse formation induced by binding to Sema4D. Here, we perform a structure-function study of the Plexin-B1 and Plexin-B2 receptors to identify the protein domains in each receptor that are required for its synaptogenic function. We also provide evidence that Plexin-B2 expression in presynaptic parvalbumin-positive interneurons is required for formation of GABAergic synapses onto excitatory pyramidal neurons in CA1. Our data reveal that Plexin-B1 and Plexin-B2 function non-redundantly to regulate GABAergic synapse formation and suggest that the transmembrane domain may underlie these functional distinctions. These findings lay the groundwork for future investigations into the precise signaling pathways required for synapse formation downstream of Plexin-B receptor signaling.
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Affiliation(s)
- Susannah S. Adel
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Zachary J. Pranske
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Tess F. Kowalski
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Nicole Kanzler
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Roshni Ray
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Catherine Carmona
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
| | - Suzanne Paradis
- Department of Biology, Brandeis University, Waltham, MA 02454, United States
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Abstract
Single-pass transmembrane receptors (SPTMRs) represent a diverse group of integral membrane proteins that are involved in many essential cellular processes, including signal transduction, cell adhesion, and transmembrane transport of materials. Dysregulation of the SPTMRs is linked with many human diseases. Despite extensive efforts in past decades, the mechanisms of action of the SPTMRs remain incompletely understood. One major hurdle is the lack of structures of the full-length SPTMRs in different functional states. Such structural information is difficult to obtain by traditional structural biology methods such as X-ray crystallography and nuclear magnetic resonance (NMR). The recent rapid development of single-particle cryo-electron microscopy (cryo-EM) has led to an exponential surge in the number of high-resolution structures of integral membrane proteins, including SPTMRs. Cryo-EM structures of SPTMRs solved in the past few years have tremendously improved our understanding of how SPTMRs function. In this review, we will highlight these progresses in the structural studies of SPTMRs by single-particle cryo-EM, analyze important structural details of each protein involved, and discuss their implications on the underlying mechanisms. Finally, we also briefly discuss remaining challenges and exciting opportunities in the field.
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Affiliation(s)
- Kai Cai
- Departments of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75231, USA
| | - Xuewu Zhang
- Departments of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75231, USA
- Departments of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75231, USA
- Corresponding Author: Xuewu Zhang, Department of pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA;
| | - Xiao-chen Bai
- Departments of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75231, USA
- Departments of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75231, USA
- Corresponding Author: Xiao-chen Bai, Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390, USA;
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4
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Shu M, Wu H, Wei S, Shi Y, Li Z, Cheng Y, Fang L, Xu C. Identification and Functional Characterization of a Novel Variant in the SEMA3A Gene in a Chinese Family with Kallmann Syndrome. Int J Endocrinol 2022; 2022:2504660. [PMID: 36267363 PMCID: PMC9578889 DOI: 10.1155/2022/2504660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Kallmann syndrome (KS) is a rare genetic disease characterized by the reproductive system and olfactory dysplasia due to the defective migration of gonadotropin-releasing hormone (GnRH) neurons. However, this disorder is clinically heterogeneous and the genotype-phenotype relationship has not been determined. OBJECTIVE The present study aimed to identify the variant causing KS in a Chinese family and evaluate the functional consequences and phenotypes associated with the novel variant. METHODS A Chinese family with KS was screened for pathogenic variants by whole-exome sequencing (WES). Bioinformatic analysis was performed to predict the consequences of the identified variant. The expression of the mutant protein was examined in vitro. RESULTS A novel heterozygous variant (NM_006080.2 : c.814G > T) in SEMA3A was identified in the patient and his father, which caused the substitution of aspartic acid with tyrosine in codon 272. It was predicted to result in pathogenic significance with a high damaging score and seriously affect protein structure by bioinformatic analysis. In vitro experiments revealed this variant could significantly decrease the expression of SEMA3A. Furthermore, it may cause the disease by failing to induce the phosphorylation of focal adhesion kinase (FAK) in GnRH neurons. CONCLUSION Identification and functional characterization of this novel variant in the SEMA3A gene in a Chinese family with Kallmann syndrome extend the genetic variant spectrum of SEMA3A and provide more data about the heterogeneity of KS, which may provide further insights into the diagnosis of KS and help patients get additional data in genetic counseling and timely treatment.
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Affiliation(s)
- Meng Shu
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Huixiao Wu
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Shuoshuo Wei
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Yingzhou Shi
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Zongyue Li
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Yiping Cheng
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Li Fang
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
| | - Chao Xu
- Department of Endocrinology and Metabolism, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong 250021, China
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Pérez Y, Bonet R, Corredor M, Domingo C, Moure A, Messeguer À, Bujons J, Alfonso I. Semaphorin 3A-Glycosaminoglycans Interaction as Therapeutic Target for Axonal Regeneration. Pharmaceuticals (Basel) 2021; 14:ph14090906. [PMID: 34577606 PMCID: PMC8465649 DOI: 10.3390/ph14090906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
Semaphorin 3A (Sema3A) is a cell-secreted protein that participates in the axonal guidance pathways. Sema3A acts as a canonical repulsive axon guidance molecule, inhibiting CNS regenerative axonal growth and propagation. Therefore, interfering with Sema3A signaling is proposed as a therapeutic target for achieving functional recovery after CNS injuries. It has been shown that Sema3A adheres to the proteoglycan component of the extracellular matrix (ECM) and selectively binds to heparin and chondroitin sulfate-E (CS-E) glycosaminoglycans (GAGs). We hypothesize that the biologically relevant interaction between Sema3A and GAGs takes place at Sema3A C-terminal polybasic region (SCT). The aims of this study were to characterize the interaction of the whole Sema3A C-terminal polybasic region (Sema3A 725–771) with GAGs and to investigate the disruption of this interaction by small molecules. Recombinant Sema3A basic domain was produced and we used a combination of biophysical techniques (NMR, SPR, and heparin affinity chromatography) to gain insight into the interaction of the Sema3A C-terminal domain with GAGs. The results demonstrate that SCT is an intrinsically disordered region, which confirms that SCT binds to GAGs and helps to identify the specific residues involved in the interaction. NMR studies, supported by molecular dynamics simulations, show that a new peptoid molecule (CSIC02) may disrupt the interaction between SCT and heparin. Our structural study paves the way toward the design of new molecules targeting these protein–GAG interactions with potential therapeutic applications.
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Affiliation(s)
- Yolanda Pérez
- NMR Facility, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
- Correspondence: (Y.P.); (I.A.)
| | - Roman Bonet
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Miriam Corredor
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Cecilia Domingo
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Alejandra Moure
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Àngel Messeguer
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Jordi Bujons
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
| | - Ignacio Alfonso
- Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; (R.B.); (M.C.); (C.D.); (A.M.); (À.M.); (J.B.)
- Correspondence: (Y.P.); (I.A.)
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6
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Lu D, Shang G, He X, Bai XC, Zhang X. Architecture of the Sema3A/PlexinA4/Neuropilin tripartite complex. Nat Commun 2021; 12:3172. [PMID: 34039996 PMCID: PMC8155012 DOI: 10.1038/s41467-021-23541-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/30/2021] [Indexed: 02/04/2023] Open
Abstract
Secreted class 3 semaphorins (Sema3s) form tripartite complexes with the plexin receptor and neuropilin coreceptor, which are both transmembrane proteins that together mediate semaphorin signal for neuronal axon guidance and other processes. Despite extensive investigations, the overall architecture of and the molecular interactions in the Sema3/plexin/neuropilin complex are incompletely understood. Here we present the cryo-EM structure of a near intact extracellular region complex of Sema3A, PlexinA4 and Neuropilin 1 (Nrp1) at 3.7 Å resolution. The structure shows a large symmetric 2:2:2 assembly in which each subunit makes multiple interactions with others. The two PlexinA4 molecules in the complex do not interact directly, but their membrane proximal regions are close to each other and poised to promote the formation of the intracellular active dimer for signaling. The structure reveals a previously unknown interface between the a2b1b2 module in Nrp1 and the Sema domain of Sema3A. This interaction places the a2b1b2 module at the top of the complex, far away from the plasma membrane where the transmembrane regions of Nrp1 and PlexinA4 embed. As a result, the region following the a2b1b2 module in Nrp1 must span a large distance to allow the connection to the transmembrane region, suggesting an essential role for the long non-conserved linkers and the MAM domain in neuropilin in the semaphorin/plexin/neuropilin complex.
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Affiliation(s)
- Defen Lu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Guijun Shang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaojing He
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Xuewu Zhang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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7
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Rozbesky D, Verhagen MG, Karia D, Nagy GN, Alvarez L, Robinson RA, Harlos K, Padilla‐Parra S, Pasterkamp RJ, Jones EY. Structural basis of semaphorin-plexin cis interaction. EMBO J 2020; 39:e102926. [PMID: 32500924 PMCID: PMC7327498 DOI: 10.15252/embj.2019102926] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 01/05/2023] Open
Abstract
Semaphorin ligands interact with plexin receptors to contribute to functions in the development of myriad tissues including neurite guidance and synaptic organisation within the nervous system. Cell-attached semaphorins interact in trans with plexins on opposing cells, but also in cis on the same cell. The interplay between trans and cis interactions is crucial for the regulated development of complex neural circuitry, but the underlying molecular mechanisms are uncharacterised. We have discovered a distinct mode of interaction through which the Drosophila semaphorin Sema1b and mouse Sema6A mediate binding in cis to their cognate plexin receptors. Our high-resolution structural, biophysical and in vitro analyses demonstrate that monomeric semaphorins can mediate a distinctive plexin binding mode. These findings suggest the interplay between monomeric vs dimeric states has a hereto unappreciated role in semaphorin biology, providing a mechanism by which Sema6s may balance cis and trans functionalities.
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Affiliation(s)
- Daniel Rozbesky
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Marieke G Verhagen
- Department of Translational NeuroscienceUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Dimple Karia
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Gergely N Nagy
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Luis Alvarez
- Cellular ImagingWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Ross A Robinson
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
Immunocore LtdAbingdonUK
| | - Karl Harlos
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Sergi Padilla‐Parra
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Cellular ImagingWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
Department of Infectious DiseasesFaculty of Life Sciences & MedicineKing's College LondonLondonUK
- Present address:
Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - R Jeroen Pasterkamp
- Department of Translational NeuroscienceUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Edith Yvonne Jones
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
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8
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Gioelli N, Maione F, Camillo C, Ghitti M, Valdembri D, Morello N, Darche M, Zentilin L, Cagnoni G, Qiu Y, Giacca M, Giustetto M, Paques M, Cascone I, Musco G, Tamagnone L, Giraudo E, Serini G. A rationally designed NRP1-independent superagonist SEMA3A mutant is an effective anticancer agent. Sci Transl Med 2019; 10:10/442/eaah4807. [PMID: 29794061 DOI: 10.1126/scitranslmed.aah4807] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 11/20/2017] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
Vascular normalizing strategies, aimed at ameliorating blood vessel perfusion and lessening tissue hypoxia, are treatments that may improve the outcome of cancer patients. Secreted class 3 semaphorins (SEMA3), which are thought to directly bind neuropilin (NRP) co-receptors that, in turn, associate with and elicit plexin (PLXN) receptor signaling, are effective normalizing agents of the cancer vasculature. Yet, SEMA3A was also reported to trigger adverse side effects via NRP1. We rationally designed and generated a safe, parenterally deliverable, and NRP1-independent SEMA3A point mutant isoform that, unlike its wild-type counterpart, binds PLXNA4 with nanomolar affinity and has much greater biochemical and biological activities in cultured endothelial cells. In vivo, when parenterally administered in mouse models of pancreatic cancer, the NRP1-independent SEMA3A point mutant successfully normalized the vasculature, inhibited tumor growth, curbed metastatic dissemination, and effectively improved the supply and anticancer activity of chemotherapy. Mutant SEMA3A also inhibited retinal neovascularization in a mouse model of age-related macular degeneration. In summary, mutant SEMA3A is a vascular normalizing agent that can be exploited to treat cancer and, potentially, other diseases characterized by pathological angiogenesis.
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Affiliation(s)
- Noemi Gioelli
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy.,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
| | - Federica Maione
- Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy.,Department of Science and Drug Technology, University of Torino, 10125 Torino, Italy
| | - Chiara Camillo
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy.,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
| | - Michela Ghitti
- Biomolecular NMR Unit, IRCCS Ospedale San Raffaele, 20132 Milano, Italy
| | - Donatella Valdembri
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy.,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
| | - Noemi Morello
- Department of Neuroscience, University of Torino School of Medicine, 10126 Torino, Italy
| | - Marie Darche
- Growth, Reparation and Tissue Regeneration Laboratory, ERL-CNRS 9215, University of Paris-Est, 94000 Créteil, France
| | - Lorena Zentilin
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
| | - Gabriella Cagnoni
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy.,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
| | - Yaqi Qiu
- Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy.,Department of Science and Drug Technology, University of Torino, 10125 Torino, Italy
| | - Mauro Giacca
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
| | - Maurizio Giustetto
- Department of Neuroscience, University of Torino School of Medicine, 10126 Torino, Italy.,National Institute of Neuroscience-Italy, 10126 Torino, Italy
| | - Michel Paques
- Vision Institute, Sorbonne University, UPMC University of Paris 06, INSERM, CNRS, 75012 Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, 75012 Paris, France
| | - Ilaria Cascone
- Growth, Reparation and Tissue Regeneration Laboratory, ERL-CNRS 9215, University of Paris-Est, 94000 Créteil, France
| | - Giovanna Musco
- Biomolecular NMR Unit, IRCCS Ospedale San Raffaele, 20132 Milano, Italy
| | - Luca Tamagnone
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy.,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
| | - Enrico Giraudo
- Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy. .,Department of Science and Drug Technology, University of Torino, 10125 Torino, Italy
| | - Guido Serini
- Department of Oncology, University of Torino School of Medicine, 10060 Candiolo, Torino, Italy. .,Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Torino, Italy
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9
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Rozbesky D, Robinson RA, Jain V, Renner M, Malinauskas T, Harlos K, Siebold C, Jones EY. Diversity of oligomerization in Drosophila semaphorins suggests a mechanism of functional fine-tuning. Nat Commun 2019; 10:3691. [PMID: 31417095 PMCID: PMC6695400 DOI: 10.1038/s41467-019-11683-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 07/30/2019] [Indexed: 12/30/2022] Open
Abstract
Semaphorin ligands and their plexin receptors are one of the major cell guidance factors that trigger localised changes in the cytoskeleton. Binding of semaphorin homodimer to plexin brings two plexins in close proximity which is a prerequisite for plexin signalling. This model appears to be too simplistic to explain the complexity and functional versatility of these molecules. Here, we determine crystal structures for all members of Drosophila class 1 and 2 semaphorins. Unlike previously reported semaphorin structures, Sema1a, Sema2a and Sema2b show stabilisation of sema domain dimer formation via a disulfide bond. Unexpectedly, our structural and biophysical data show Sema1b is a monomer suggesting that semaphorin function may not be restricted to dimers. We demonstrate that semaphorins can form heterodimers with members of the same semaphorin class. This heterodimerization provides a potential mechanism for cross-talk between different plexins and co-receptors to allow fine-tuning of cell signalling.
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Affiliation(s)
- Daniel Rozbesky
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK.
| | - Ross A Robinson
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
- Immunocore Ltd, Milton Park, Abingdon, OX14 4RY, UK
| | - Vitul Jain
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Max Renner
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Karl Harlos
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK.
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10
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St Clair RM, Dumas CM, Williams KS, Goldstein MT, Stant EA, Ebert AM, Ballif BA. PKC induces release of a functional ectodomain of the guidance cue semaphorin6A. FEBS Lett 2019; 593:3015-3028. [PMID: 31378926 DOI: 10.1002/1873-3468.13561] [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: 01/11/2019] [Revised: 07/16/2019] [Accepted: 07/25/2019] [Indexed: 01/06/2023]
Abstract
Semaphorins (Semas) are a family of secreted and transmembrane proteins that play critical roles in development. Interestingly, several vertebrate transmembrane Sema classes are capable of producing functional soluble ectodomains. However, little is known of soluble Sema6 ectodomains in the nervous system. Herein, we show that the soluble Sema6A ectodomain, sSema6A, exhibits natural and protein kinase C (PKC)-induced release. We show that PKC mediates Sema6A phosphorylation at specific sites and while this phosphorylation is not the primary mechanism regulating sSema6A production, we found that the intracellular domain confers resistance to ectodomain release. Finally, sSema6A is functional as it promotes the cohesion of zebrafish early eye field explants. This suggests that in addition to its canonical contact-mediated functions, Sema6A may have regulated, long-range, forward-signaling capacity.
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Affiliation(s)
- Riley M St Clair
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Caroline M Dumas
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Kori S Williams
- Department of Biology, University of Vermont, Burlington, VT, USA
| | | | | | - Alicia M Ebert
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Bryan A Ballif
- Department of Biology, University of Vermont, Burlington, VT, USA
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11
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Class-3 Semaphorins and Their Receptors: Potent Multifunctional Modulators of Tumor Progression. Int J Mol Sci 2019; 20:ijms20030556. [PMID: 30696103 PMCID: PMC6387194 DOI: 10.3390/ijms20030556] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 12/28/2022] Open
Abstract
Semaphorins are the products of a large gene family containing 28 genes of which 21 are found in vertebrates. Class-3 semaphorins constitute a subfamily of seven vertebrate semaphorins which differ from the other vertebrate semaphorins in that they are the only secreted semaphorins and are distinguished from other semaphorins by the presence of a basic domain at their C termini. Class-3 semaphorins were initially characterized as axon guidance factors, but have subsequently been found to regulate immune responses, angiogenesis, lymphangiogenesis, and a variety of additional physiological and developmental functions. Most class-3 semaphorins transduce their signals by binding to receptors belonging to the neuropilin family which subsequently associate with receptors of the plexin family to form functional class-3 semaphorin receptors. Recent evidence suggests that class-3 semaphorins also fulfill important regulatory roles in multiple forms of cancer. Several class-3 semaphorins function as endogenous inhibitors of tumor angiogenesis. Others were found to inhibit tumor metastasis by inhibition of tumor lymphangiogenesis, by direct effects on the behavior of tumor cells, or by modulation of immune responses. Notably, some semaphorins such as sema3C and sema3E have also been found to potentiate tumor progression using various mechanisms. This review focuses on the roles of the different class-3 semaphorins in tumor progression.
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12
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Abstract
Semaphorins are extracellular signaling proteins that are essential for the development and maintenance of many organs and tissues. The more than 20-member semaphorin protein family includes secreted, transmembrane and cell surface-attached proteins with diverse structures, each characterized by a single cysteine-rich extracellular sema domain, the defining feature of the family. Early studies revealed that semaphorins function as axon guidance molecules, but it is now understood that semaphorins are key regulators of morphology and motility in many different cell types including those that make up the nervous, cardiovascular, immune, endocrine, hepatic, renal, reproductive, respiratory and musculoskeletal systems, as well as in cancer cells. Semaphorin signaling occurs predominantly through Plexin receptors and results in changes to the cytoskeletal and adhesive machinery that regulate cellular morphology. While much remains to be learned about the mechanisms underlying the effects of semaphorins, exciting work has begun to reveal how semaphorin signaling is fine-tuned through different receptor complexes and other mechanisms to achieve specific outcomes in various cellular contexts and physiological systems. These and future studies will lead to a more complete understanding of semaphorin-mediated development and to a greater understanding of how these proteins function in human disease.
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Affiliation(s)
- Laura Taylor Alto
- Departments of Neuroscience and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jonathan R Terman
- Departments of Neuroscience and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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13
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Abstract
Axon guidance relies on a combinatorial code of receptor and ligand interactions that direct adhesive/attractive and repulsive cellular responses. Recent structural data have revealed many of the molecular mechanisms that govern these interactions and enabled the design of sophisticated mutant tools to dissect their biological functions. Here, we discuss the structure/function relationships of four major classes of guidance cues (ephrins, semaphorins, slits, netrins) and examples of morphogens (Wnt, Shh) and of cell adhesion molecules (FLRT). These cell signaling systems rely on specific modes of receptor-ligand binding that are determined by selective binding sites; however, defined structure-encoded receptor promiscuity also enables cross talk between different receptor/ligand families and can also involve extracellular matrix components. A picture emerges in which a multitude of highly context-dependent structural assemblies determines the finely tuned cellular behavior required for nervous system development.
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Affiliation(s)
- Elena Seiradake
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, United Kingdom;
| | - E Yvonne Jones
- Wellcome Trust Centre for Human Genetics, Oxford University, Oxford OX3 7BN, United Kingdom;
| | - Rüdiger Klein
- Max Planck Institute of Neurobiology, 82152 Munich-Martinsried, Germany;
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
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Abstract
Secreted class 3 semaphorins (Sema3), which signal through holoreceptor complexes that are formed by different subunits, such as neuropilins (Nrps), proteoglycans, and plexins, were initially characterized as fundamental regulators of axon guidance during embryogenesis. Subsequently, Sema3A, Sema3C, Sema3D, and Sema3E were discovered to play crucial roles in cardiovascular development, mainly acting through Nrp1 and Plexin D1, which funnels the signal of multiple Sema3 in vascular endothelial cells. Mechanistically, Sema3 proteins control cardiovascular patterning through the enzymatic GTPase-activating-protein activity of the cytodomain of Plexin D1, which negatively regulates the function of Rap1, a small GTPase that is well-known for its ability to drive vascular morphogenesis and to elicit the conformational activation of integrin adhesion receptors.
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Affiliation(s)
- Donatella Valdembri
- a Department of Oncology , University of Torino School of Medicine , Candiolo, Torino , Italy.,b Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia (FPO) Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) , Candiolo, Torino , Italy
| | - Donatella Regano
- c Laboratory of Transgenic Mouse Models, Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia (FPO) Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) , Candiolo, Torino , Italy.,d Department of Science and Drug Technology , University of Torino , Candiolo, Torino , Italy
| | - Federica Maione
- c Laboratory of Transgenic Mouse Models, Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia (FPO) Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) , Candiolo, Torino , Italy.,d Department of Science and Drug Technology , University of Torino , Candiolo, Torino , Italy
| | - Enrico Giraudo
- c Laboratory of Transgenic Mouse Models, Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia (FPO) Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) , Candiolo, Torino , Italy.,d Department of Science and Drug Technology , University of Torino , Candiolo, Torino , Italy
| | - Guido Serini
- a Department of Oncology , University of Torino School of Medicine , Candiolo, Torino , Italy.,b Laboratory of Cell Adhesion Dynamics, Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia (FPO) Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) , Candiolo, Torino , Italy
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15
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Cariboni A, André V, Chauvet S, Cassatella D, Davidson K, Caramello A, Fantin A, Bouloux P, Mann F, Ruhrberg C. Dysfunctional SEMA3E signaling underlies gonadotropin-releasing hormone neuron deficiency in Kallmann syndrome. J Clin Invest 2015; 125:2413-28. [PMID: 25985275 DOI: 10.1172/jci78448] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 04/02/2015] [Indexed: 01/09/2023] Open
Abstract
Individuals with an inherited deficiency in gonadotropin-releasing hormone (GnRH) have impaired sexual reproduction. Previous genetic linkage studies and sequencing of plausible gene candidates have identified mutations associated with inherited GnRH deficiency, but the small number of affected families and limited success in validating candidates have impeded genetic diagnoses for most patients. Using a combination of exome sequencing and computational modeling, we have identified a shared point mutation in semaphorin 3E (SEMA3E) in 2 brothers with Kallmann syndrome (KS), which causes inherited GnRH deficiency. Recombinant wild-type SEMA3E protected maturing GnRH neurons from cell death by triggering a plexin D1-dependent (PLXND1-dependent) activation of PI3K-mediated survival signaling. In contrast, recombinant SEMA3E carrying the KS-associated mutation did not protect GnRH neurons from death. In murine models, lack of either SEMA3E or PLXND1 increased apoptosis of GnRH neurons in the developing brain, reducing innervation of the adult median eminence by GnRH-positive neurites. GnRH neuron deficiency in male mice was accompanied by impaired testes growth, a characteristic feature of KS. Together, these results identify SEMA3E as an essential gene for GnRH neuron development, uncover a neurotrophic function for SEMA3E in the developing brain, and elucidate SEMA3E/PLXND1/PI3K signaling as a mechanism that prevents GnRH neuron deficiency.
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16
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Pascoe HG, Wang Y, Zhang X. Structural mechanisms of plexin signaling. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 118:161-8. [PMID: 25824683 DOI: 10.1016/j.pbiomolbio.2015.03.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 02/20/2015] [Accepted: 03/20/2015] [Indexed: 02/03/2023]
Abstract
Signaling through plexin, the major cell surface receptor for semaphorin, plays critical roles in regulating processes such as neuronal axon guidance, angiogenesis and immune response. Plexin is normally kept inactive in the absence of semaphorin. Upon binding of semaphorin to the extracellular region, plexin is activated and transduces signal to the inside of the cell through its cytoplasmic region. The GTPase Activating Protein (GAP) domain in the plexin cytoplasmic region mediates the major intracellular signaling pathway. The substrate specificity and regulation mechanisms of the GAP domain have only been revealed recently. Many intracellular proteins serve as either upstream regulators or downstream transducers by directly interacting with plexin. The mechanisms of action for some of these proteins also start to emerge from recent studies. We review here these advances in the mechanistic understanding of plexin intracellular signaling from a structural perspective.
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Affiliation(s)
- Heath G Pascoe
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yuxiao Wang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xuewu Zhang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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17
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Mishra R, Kumar D, Tomar D, Chakraborty G, Kumar S, Kundu GC. The potential of class 3 semaphorins as both targets and therapeutics in cancer. Expert Opin Ther Targets 2014; 19:427-42. [PMID: 25434284 DOI: 10.1517/14728222.2014.986095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
INTRODUCTION Semaphorins have been originally identified as a family of evolutionary conserved soluble or membrane-associated proteins involved in diverse developmental phenomena. This family of proteins profoundly influences numerous pathophysiological processes, including organogenesis, cardiovascular development and immune response. Apart from steering the neural networking process, these are implicated in a broad range of biological operations including regulation of tumor progression and angiogenesis. AREAS COVERED Members of class 3 semaphorin family are known to modulate various cellular processes involved in malignant transformation. Some of the family members trigger diverse signaling processes involved in tumor progression and angiogenesis by binding with plexin and neuropilin. A better understanding of the various signaling mechanisms by which semaphorins modulate tumor progression and angiogenesis may serve as crucial tool in crafting new semaphorin-based anticancer therapy. These include treatment with recombinant tumor suppressive semaphorins or inhibition of tumor-promoting semaphorins by their specific siRNAs, small-molecule inhibitors or specific receptors using neutralizing antibodies or blocking peptides that might serve as novel strategies for effective management of cancers. EXPERT OPINION This review focuses on all the possible avenues to explore various members of class 3 semaphorin family to serve as therapeutics for combating cancer.
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Affiliation(s)
- Rosalin Mishra
- Loboratory of Tumor Biology, Angiogenesis and Nanomedicine Research, National Center for Cell Science (NCCS) , Pune 411007 , India
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18
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Dejda A, Mawambo G, Cerani A, Miloudi K, Shao Z, Daudelin JF, Boulet S, Oubaha M, Beaudoin F, Akla N, Henriques S, Menard C, Stahl A, Delisle JS, Rezende FA, Labrecque N, Sapieha P. Neuropilin-1 mediates myeloid cell chemoattraction and influences retinal neuroimmune crosstalk. J Clin Invest 2014; 124:4807-22. [PMID: 25271625 DOI: 10.1172/jci76492] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 08/28/2014] [Indexed: 12/28/2022] Open
Abstract
Immunological activity in the CNS is largely dependent on an innate immune response and is heightened in diseases, such as diabetic retinopathy, multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease. The molecular dynamics governing immune cell recruitment to sites of injury and disease in the CNS during sterile inflammation remain poorly defined. Here, we identified a subset of mononuclear phagocytes (MPs) that responds to local chemotactic cues that are conserved among central neurons, vessels, and immune cells. Patients suffering from late-stage proliferative diabetic retinopathy (PDR) had elevated vitreous semaphorin 3A (SEMA3A). Using a murine model, we found that SEMA3A acts as a potent attractant for neuropilin-1-positive (NRP-1-positive) MPs. These proangiogenic MPs were selectively recruited to sites of pathological neovascularization in response to locally produced SEMA3A as well as VEGF. NRP-1-positive MPs were essential for disease progression, as NRP-1-deficient MPs failed to enter the retina in a murine model of oxygen-induced retinopathy (OIR), a proxy for PDR. OIR mice with NRP-1-deficient MPs exhibited decreased vascular degeneration and diminished pathological preretinal neovascularization. Intravitreal administration of a NRP-1-derived trap effectively mimicked the therapeutic benefits observed in mice lacking NRP-1-expressing MPs. Our findings indicate that NRP-1 is an obligate receptor for MP chemotaxis, bridging neural ischemia to an innate immune response in neovascular retinal disease.
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19
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Nasarre P, Gemmill RM, Drabkin HA. The emerging role of class-3 semaphorins and their neuropilin receptors in oncology. Onco Targets Ther 2014; 7:1663-87. [PMID: 25285016 PMCID: PMC4181631 DOI: 10.2147/ott.s37744] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The semaphorins, discovered over 20 years ago, are a large family of secreted or transmembrane and glycophosphatidylinositol -anchored proteins initially identified as axon guidance molecules crucial for the development of the nervous system. It has now been established that they also play important roles in organ development and function, especially involving the immune, respiratory, and cardiovascular systems, and in pathological disorders, including cancer. During tumor progression, semaphorins can have both pro- and anti-tumor functions, and this has created complexities in our understanding of these systems. Semaphorins may affect tumor growth and metastases by directly targeting tumor cells, as well as indirectly by interacting with and influencing cells from the micro-environment and vasculature. Mechanistically, semaphorins, through binding to their receptors, neuropilins and plexins, affect pathways involved in cell adhesion, migration, invasion, proliferation, and survival. Importantly, neuropilins also act as co-receptors for several growth factors and enhance their signaling activities, while class 3 semaphorins may interfere with this. In this review, we focus on the secreted class 3 semaphorins and their neuropilin co-receptors in cancer, including aspects of their signaling that may be clinically relevant.
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Affiliation(s)
- Patrick Nasarre
- Division of Hematology-Oncology, The Hollings Cancer Center and Medical University of South Carolina, Charleston, SC, USA
| | - Robert M Gemmill
- Division of Hematology-Oncology, The Hollings Cancer Center and Medical University of South Carolina, Charleston, SC, USA
| | - Harry A Drabkin
- Division of Hematology-Oncology, The Hollings Cancer Center and Medical University of South Carolina, Charleston, SC, USA
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21
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Neuron-derived semaphorin 3A is an early inducer of vascular permeability in diabetic retinopathy via neuropilin-1. Cell Metab 2013; 18:505-18. [PMID: 24093675 DOI: 10.1016/j.cmet.2013.09.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 07/20/2013] [Accepted: 08/23/2013] [Indexed: 01/01/2023]
Abstract
The deterioration of the inner blood-retinal barrier and consequent macular edema is a cardinal manifestation of diabetic retinopathy (DR) and the clinical feature most closely associated with loss of sight. We provide evidence from both human and animal studies for the critical role of the classical neuronal guidance cue, semaphorin 3A, in instigating pathological vascular permeability in diabetic retinas via its cognate receptor neuropilin-1. We reveal that semaphorin 3A is induced in early hyperglycemic phases of diabetes within the neuronal retina and precipitates initial breakdown of endothelial barrier function. We demonstrate, by a series of orthogonal approaches, that neutralization of semaphorin 3A efficiently prevents diabetes-induced retinal vascular leakage in a stage of the disease when vascular endothelial growth factor neutralization is inefficient. These observations were corroborated in Tg(Cre-Esr1)/Nrp1(flox/flox) conditional knockout mice. Our findings identify a therapeutic target for macular edema and provide further evidence for neurovascular crosstalk in the pathogenesis of DR.
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22
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Wang Y, Pascoe HG, Brautigam CA, He H, Zhang X. Structural basis for activation and non-canonical catalysis of the Rap GTPase activating protein domain of plexin. eLife 2013; 2:e01279. [PMID: 24137545 PMCID: PMC3787391 DOI: 10.7554/elife.01279] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 08/22/2013] [Indexed: 12/14/2022] Open
Abstract
Plexins are cell surface receptors that bind semaphorins and transduce signals for regulating neuronal axon guidance and other processes. Plexin signaling depends on their cytoplasmic GTPase activating protein (GAP) domain, which specifically inactivates the Ras homolog Rap through an ill-defined non-canonical catalytic mechanism. The plexin GAP is activated by semaphorin-induced dimerization, the structural basis for which remained unknown. Here we present the crystal structures of the active dimer of zebrafish PlexinC1 cytoplasmic region in the apo state and in complex with Rap. The structures show that the dimerization induces a large-scale conformational change in plexin, which opens the GAP active site to allow Rap binding. Plexin stabilizes the switch II region of Rap in an unprecedented conformation, bringing Gln63 in Rap into the active site for catalyzing GTP hydrolysis. The structures also explain the unique Rap-specificity of plexins. Mutational analyses support that these mechanisms underlie plexin activation and signaling. DOI:http://dx.doi.org/10.7554/eLife.01279.001.
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Affiliation(s)
- Yuxiao Wang
- Department of Pharmacology , University of Texas Southwestern Medical Center , Dallas , United States
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23
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Siebold C, Jones EY. Structural insights into semaphorins and their receptors. Semin Cell Dev Biol 2013; 24:139-45. [PMID: 23253452 DOI: 10.1016/j.semcdb.2012.11.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 11/26/2012] [Indexed: 10/27/2022]
Abstract
Ten years ago nothing was known of the three-dimensional structure of members of the semaphorin family of cell guidance cues, nor of their major receptors, the plexins. The structural biology of this cell surface ligand-receptor system has now come of age. Detailed atomic level information is available on the architecture of semaphorin and plexin ectodomains and their recognition complexes. Similarly the structure of the plexin cytoplasmic region, and its interactions with members of the Rho family of small GTPases have been unveiled. These structural analyses, in combination with biochemical, biophysical and cellular studies, have progressed our understanding of this signalling system into the realm of molecular mechanism.
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Affiliation(s)
- Christian Siebold
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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24
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Serini G, Bussolino F, Maione F, Giraudo E. Class 3 semaphorins: physiological vascular normalizing agents for anti-cancer therapy. J Intern Med 2013. [PMID: 23198760 DOI: 10.1111/joim.12017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Findings from preclinical and clinical studies show that vascular normalization represents a novel strategy to enhance the efficacy of and overcome the acquired resistance to anti-angiogenic therapies in cancer. Several mechanisms of tumour vessel normalization have been revealed. Amongst them, secreted class 3 semaphorins (Sema3), which regulate axon guidance and angiogenesis, have been recently identified as novel vascular normalizing agents that inhibit metastatic dissemination by restoring vascular function. Here, we discuss the different biological functions and mechanisms of action of Sema3 in the context of tumour vascular normalization, and their impact on the different cellular components of the tumour microenvironment.
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Affiliation(s)
- G Serini
- Institute for Cancer Research at Candiolo (IRCC), University of Torino, Turin, Italy
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Wang Y, He H, Srivastava N, Vikarunnessa S, Chen YB, Jiang J, Cowan CW, Zhang X. Plexins are GTPase-activating proteins for Rap and are activated by induced dimerization. Sci Signal 2012; 5:ra6. [PMID: 22253263 DOI: 10.1126/scisignal.2002636] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plexins are cell surface receptors that bind to semaphorins and transduce signals that regulate neuronal development, immune responses, and other processes. Signaling through plexins has been proposed to rely on specific guanosine triphosphatase (GTPase)-activating protein (GAP) activity for R-Ras and M-Ras. Activation of this GAP activity of plexins appears to require simultaneous binding of semaphorin to the plexin extracellular domain and of the Rho GTPases Rac1 or Rnd1 to the cytoplasmic region. However, GAP activity of plexins has eluded detection in several recent studies. We show that the purified cytoplasmic region of plexin uses a noncanonical catalytic mechanism to act as a GAP for Rap, but not for R-Ras or M-Ras. The RapGAP activity of plexins was autoinhibited and was activated by induced dimerization. Biochemical and crystallographic analyses demonstrated that binding of Rho GTPases did not directly contribute to activation of plexin RapGAP activity. Semaphorin stimulated the RapGAP activity of full-length plexin in cells, which was required for plexin-mediated neuronal growth cone collapse. Together, these findings define a pathway for plexin signaling and provide insights into the mechanism for semaphorin-induced activation of plexins.
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Affiliation(s)
- Yuxiao Wang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75063, USA
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Gay CM, Zygmunt T, Torres-Vázquez J. Diverse functions for the semaphorin receptor PlexinD1 in development and disease. Dev Biol 2011; 349:1-19. [PMID: 20880496 PMCID: PMC2993764 DOI: 10.1016/j.ydbio.2010.09.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 09/14/2010] [Accepted: 09/18/2010] [Indexed: 01/13/2023]
Abstract
Plexins are a family of single-pass transmembrane proteins that serve as cell surface receptors for Semaphorins during the embryonic development of animals. Semaphorin-Plexin signaling is critical for many cellular aspects of organogenesis, including cell migration, proliferation and survival. Until recently, little was known about the function of PlexinD1, the sole member of the vertebrate-specific PlexinD (PlxnD1) subfamily. Here we review novel findings about PlxnD1's roles in the development of the cardiovascular, nervous and immune systems and salivary gland branching morphogenesis and discuss new insights concerning the molecular mechanisms of PlxnD1 activity.
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Affiliation(s)
- Carl M Gay
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University Langone Medical Center, 540 First Avenue, 4th floor, lab 14, New York, NY 10016, USA
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Janssen BJC, Robinson RA, Pérez-Brangulí F, Bell CH, Mitchell KJ, Siebold C, Jones EY. Structural basis of semaphorin-plexin signalling. Nature 2010; 467:1118-22. [PMID: 20877282 DOI: 10.1038/nature09468] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 09/06/2010] [Indexed: 01/25/2023]
Abstract
Cell-cell signalling of semaphorin ligands through interaction with plexin receptors is important for the homeostasis and morphogenesis of many tissues and is widely studied for its role in neural connectivity, cancer, cell migration and immune responses. SEMA4D and Sema6A exemplify two diverse vertebrate, membrane-spanning semaphorin classes (4 and 6) that are capable of direct signalling through members of the two largest plexin classes, B and A, respectively. In the absence of any structural information on the plexin ectodomain or its interaction with semaphorins the extracellular specificity and mechanism controlling plexin signalling has remained unresolved. Here we present crystal structures of cognate complexes of the semaphorin-binding regions of plexins B1 and A2 with semaphorin ectodomains (human PLXNB1(1-2)-SEMA4D(ecto) and murine PlxnA2(1-4)-Sema6A(ecto)), plus unliganded structures of PlxnA2(1-4) and Sema6A(ecto). These structures, together with biophysical and cellular assays of wild-type and mutant proteins, reveal that semaphorin dimers independently bind two plexin molecules and that signalling is critically dependent on the avidity of the resulting bivalent 2:2 complex (monomeric semaphorin binds plexin but fails to trigger signalling). In combination, our data favour a cell-cell signalling mechanism involving semaphorin-stabilized plexin dimerization, possibly followed by clustering, which is consistent with previous functional data. Furthermore, the shared generic architecture of the complexes, formed through conserved contacts of the amino-terminal seven-bladed β-propeller (sema) domains of both semaphorin and plexin, suggests that a common mode of interaction triggers all semaphorin-plexin based signalling, while distinct insertions within or between blades of the sema domains determine binding specificity.
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Affiliation(s)
- Bert J C Janssen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
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Takahashi K, Tomizawa K, Ishida M, Hirokawa K, Takahashi H. Identification and tissue-specific expression of a novel isoform of Semaphorin 3D. Biochim Biophys Acta Gen Subj 2009; 1790:395-400. [PMID: 19345252 DOI: 10.1016/j.bbagen.2009.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 03/23/2009] [Accepted: 03/24/2009] [Indexed: 10/21/2022]
Abstract
BACKGROUND Semaphorins are a family of secreted and membrane-associated proteins involved in axon guidance in the developing brain as well as morphogenesis in various organs. There has been no report on the expression of different transcripts of the genes encoding Class 3 Semaphorins with different protein structures. METHODS Molecular cloning of rat Semaphorin 3D gene and the expression analysis at gene and protein levels were performed. RESULTS We have isolated two cDNAs encoding rat Sema 3D, a Class 3 Semaphorin. One clone is predicted to encode a protein with a structure common to Class 3 Semaphorins. The other clone encodes a novel isoform of Sema 3D lacking half of the C2-type Ig domain and the entire basic region; this isoform is predicted to have a different structure from Class 3 Semaphorins. Analysis of protein expression using a cell culture system revealed that this splice variant isoform is not secreted into the media, whereas the classical Class 3 isoform is a secreted protein. The expression of each isoform shows tissue-specificity. GENERAL SIGNIFICANCE Our present findings suggest that gene regulation, via an alternative splicing mechanism, affects not only the tissue-specificity of Sema 3D expression, but also the distance over which it can act.
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Affiliation(s)
- Kaoru Takahashi
- Developmental Neurobiology Group, Mitsubishi Kagaku Institute of Life Sciences, Machida, Tokyo 194-8511, Japan
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Role of semaphorins during axon growth and guidance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 621:50-64. [PMID: 18269210 DOI: 10.1007/978-0-387-76715-4_4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Neufeld G, Kessler O. The semaphorins: versatile regulators of tumour progression and tumour angiogenesis. Nat Rev Cancer 2008; 8:632-45. [PMID: 18580951 DOI: 10.1038/nrc2404] [Citation(s) in RCA: 300] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The semaphorins and their receptors, the neuropilins and the plexins, were originally characterized as constituents of the complex regulatory system responsible for the guidance of axons during the development of the central nervous system. However, a growing body of evidence indicates that various semaphorins can either promote or inhibit tumour progression through the promotion or inhibition of processes such as tumour angiogenesis, tumour metastasis and tumour cell survival. This Review focuses on the emerging role of the semaphorins in cancer.
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Affiliation(s)
- Gera Neufeld
- Cancer Research and Vascular Biology Center, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, P.O. Box 9679, 1 Efron Street, Haifa, 31096, Israel.
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Wang X, Zhang W, Cheever T, Schwarz V, Opperman K, Hutter H, Koepp D, Chen L. The C. elegans L1CAM homologue LAD-2 functions as a coreceptor in MAB-20/Sema2 mediated axon guidance. ACTA ACUST UNITED AC 2008; 180:233-46. [PMID: 18195110 PMCID: PMC2213605 DOI: 10.1083/jcb.200704178] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The L1 cell adhesion molecule (L1CAM) participates in neuronal development. Mutations in the human L1 gene can cause the neurological disorder CRASH (corpus callosum hypoplasia, retardation, adducted thumbs, spastic paraplegia, and hydrocephalus). This study presents genetic data that shows that L1-like adhesion gene 2 (LAD-2), a Caenorhabditis elegans L1CAM, functions in axon pathfinding. In the SDQL neuron, LAD-2 mediates dorsal axon guidance via the secreted MAB-20/Sema2 and PLX-2 plexin receptor, the functions of which have largely been characterized in epidermal morphogenesis. We use targeted misexpression experiments to provide in vivo evidence that MAB-20/Sema2 acts as a repellent to SDQL. Coimmunoprecipitation assays reveal that MAB-20 weakly interacts with PLX-2; this interaction is increased in the presence of LAD-2, which can interact independently with MAB-20 and PLX-2. These results suggest that LAD-2 functions as a MAB-20 coreceptor to secure MAB-20 coupling to PLX-2. In vertebrates, L1 binds neuropilin1, the obligate receptor to the secreted Sema3A. However, invertebrates lack neuropilins. LAD-2 may thus function in the semaphorin complex by combining the roles of neuropilins and L1CAMs.
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Affiliation(s)
- Xuelin Wang
- Department of Genetics, Cell Biology, and Development, Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
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Roth L, Nasarre C, Dirrig-Grosch S, Aunis D, Crémel G, Hubert P, Bagnard D. Transmembrane domain interactions control biological functions of neuropilin-1. Mol Biol Cell 2007; 19:646-54. [PMID: 18045991 DOI: 10.1091/mbc.e07-06-0625] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Neuropilin-1 (NRP1) is a transmembrane receptor playing a pivotal role in the control of semaphorins and VEGF signaling pathways. The exact mechanism controlling semaphorin receptor complex formation is unknown. A structural analysis and modeling of NRP1 revealed a putative dimerization GxxxG motif potentially important for NRP1 dimerization and oligomerization. Our data show that this motif mediates the dimerization of the transmembrane domain of NRP1 as demonstrated by a dimerization assay (ToxLuc assay) performed in natural membrane and FRET analysis. A synthetic peptide derived from the transmembrane segment of NRP1 abolished the inhibitory effect of Sema3A. This effect depends on the capacity of the peptide to interfere with NRP1 dimerization and the formation of oligomeric complexes. Mutation of the GxxxG dimerization motif in the transmembrane domain of NRP1 confirmed its biological importance for Sema3A signaling. Overall, our results shed light on an essential step required for semaphorin signaling and provide novel evidence for the crucial role of transmembrane domain of bitopic protein containing GxxxG motif in the formation of receptor complexes that are a prerequisite for cell signaling.
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Affiliation(s)
- Lise Roth
- INSERM U575 Physiopathologie du Système Nerveux, Université Louis Pasteur, 67084 Strasbourg, France
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Abstract
Neuropilins (NRP) are receptors for the class 3 semaphorin (SEMA3) family of axon guidance molecules and the vascular endothelial growth factor (VEGF) family of angiogenesis factors. Although the seminal studies on SEMA3s and NRPs first showed them to be mediators of axon guidance, it has become very apparent that these proteins play an important role in vascular and tumor biology as well. Neuronal guidance and angiogenesis are regulated similarly at the molecular level. For example, SEMA3s not only repel neurons and collapse axon growth cones, but have similar effects on endothelial cells and tumor cells. Preclinical studies indicate that SEMA3F is a potent inhibitor of tumor angiogenesis and metastasis. In addition, neutralizing antibodies to NRP1 enhance the effects of anti-VEGF antibodies in suppressing tumor growth in xenograft models. This article reviews NRP and SEMA3 structural interactions and their role in developmental angiogenesis, tumor angiogenesis and metastasis based on cell culture, zebrafish and murine studies.
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Affiliation(s)
- Diane R Bielenberg
- Vascular Biology Program, Children's Hospital, Department of Surgery, Harvard Medical School, Karp Family Research Laboratories, 12.211, 300 Longwood Avenue, Boston, MA 02115, USA.
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Toyofuku T, Yabuki M, Kamei J, Kamei M, Makino N, Kumanogoh A, Hori M. Semaphorin-4A, an activator for T-cell-mediated immunity, suppresses angiogenesis via Plexin-D1. EMBO J 2007; 26:1373-84. [PMID: 17318185 PMCID: PMC1817636 DOI: 10.1038/sj.emboj.7601589] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Accepted: 01/09/2007] [Indexed: 01/13/2023] Open
Abstract
Originally identified as axon guidance molecules, semaphorins are now known to be widely expressed mediators that play significant roles in immune responses and organ morphogenesis. However, not much is known about the signaling pathways via which they exert their organ-specific effects. Here we demonstrate that Sema4A, previously identified as an activator of T-cell-mediated immunity, is expressed in endothelial cells, where it suppresses vascular endothelial growth factor (VEGF)-mediated endothelial cell migration and proliferation in vitro and angiogenesis in vivo. Mice lacking Sema4A exhibit enhanced angiogenesis in response to VEGF or inflammatory stimuli. In addition, binding and functional experiments revealed Plexin-D1 to be a receptor for Sema4A on endothelial cells, indicating that Sema4A exerts organ-specific activities via different receptor-mediated signaling pathways: via Plexin-D1 in the endothelial cells and via T-cell immunoglobulin and mucin domain-2 in T cells. The effects of Sema4A on endothelial cells are dependent on its ability to suppress VEGF-mediated Rac activation and integrin-dependent cell adhesion. It thus appears that Sema4A-Plexin-D1 signaling negatively regulates angiogenesis.
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Affiliation(s)
- Toshihiko Toyofuku
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
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Abstract
Semaphorins are secreted, transmembrane, and GPI-linked proteins, defined by cysteine-rich semaphorin protein domains, that have important roles in a variety of tissues. Humans have 20 semaphorins, Drosophila has five, and two are known from DNA viruses; semaphorins are also found in nematodes and crustaceans but not in non-animals. They are grouped into eight classes on the basis of phylogenetic tree analyses and the presence of additional protein motifs. The expression of semaphorins has been described most fully in the nervous system, but they are also present in most, or perhaps all, other tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. More recently, they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. A common theme in the mechanisms of semaphorin function is that they alter the cytoskeleton and the organization of actin filaments and the microtubule network. These effects occur primarily through binding of semaphorins to their receptors, although transmembrane semaphorins also serve as receptors themselves. The best characterized receptors for mediating semaphorin signaling are members of the neuropilin and plexin families of transmembrane proteins. Plexins, in particular, are thought to control many of the functional effects of semaphorins; the molecular mechanisms of semaphorin signaling are still poorly understood, however. Given the importance of semaphorins in a wide range of functions, including neural connectivity, angiogenesis, immunoregulation, and cancer, much remains to be learned about these proteins and their roles in pathology and human disease.
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Affiliation(s)
- Umar Yazdani
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Guttmann-Raviv N, Kessler O, Shraga-Heled N, Lange T, Herzog Y, Neufeld G. The neuropilins and their role in tumorigenesis and tumor progression. Cancer Lett 2006; 231:1-11. [PMID: 16356825 DOI: 10.1016/j.canlet.2004.12.047] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Accepted: 12/22/2004] [Indexed: 11/27/2022]
Abstract
The neuropilins were originally described as receptors for the six axon guidance factors belonging to the class-3 semaphorins. They were subsequently found to function in addition as receptors for specific splice forms of angiogenic factors belonging to the VEGF family. The neuropilins are expressed in many types of cancer cells, in endothelial cells and in additional many types of normal diploid cell types. Recent findings indicate that the neuropilins and their associated plexin and tyrosine-kinase VEGF receptors play a regulatory role in developmental angiogenesis as well as in tumor angiogenesis. The neuropilin ligands belonging to the semaphorin family as well as the various VEGF's function as modulators of angiogenesis and tumor angiogenesis. Furthermore, since many types of cancer cells express neuropilins and neuropilin associated receptors, it is not surprising that various neuropilin ligands can modulate the behavior of cancer cells directly leading to the potentiation or inhibition of tumor progression.
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Affiliation(s)
- Noga Guttmann-Raviv
- Cancer and Vascular Biology Research Center, Rappaport Research Institute in the Medical Sciences, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, 1 Efron St., P.O. Box 9679, Haifa 31096, Israel
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Steffensky M, Steinbach K, Schwarz U, Schlosshauer B. Differential impact of semaphorin 3E and 3A on CNS axons. Int J Dev Neurosci 2005; 24:65-72. [PMID: 16338115 DOI: 10.1016/j.ijdevneu.2005.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 10/24/2005] [Accepted: 10/26/2005] [Indexed: 11/20/2022] Open
Abstract
During the development of the central nervous system (CNS), the correct wiring of outgrowing neurites is mediated by antagonistic mechanisms. Aberrant growth is prevented by repulsive factors such as semaphorins. Expression of the ligands Sema3A and -3E and the receptors neuropilin Npn-1, -2a and -2b in the chick visual system were analyzed by RT-PCR. Whereas Sema3A and its major receptor Npn-1 were abundant, Sema3E and Npn-2 isoform expression was highly restricted and developmentally regulated. Peak expression occurred during retinal axon innervation of the tectum. Functional in vitro assays with recombinant proteins revealed a topography-specific growth cone collapsing activity of Sema3A for tectal axons. Interestingly, whereas tectal axons collapsed in a topographic-specific manner only in the presence of Sema3A, retinal axons responded only to Sema3E. The collapsing activity was intracellularly mediated by cGMP. For a detailed analysis of neuronal responses to sempahorins, time lapse video recording was performed. When tectal and retinal axons were pre-exposed to brain-derived neurotrophic factor (BDNF), a protective effect was evident only in the case of retinal axons. Our results suggest a molecular mechanism whereby ingrowth of retinal axons into the tectum can be regulated by Sema3E/BDNF modulation without disturbing tectal axon growth out of the tectum mediated by Sema3A.
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Affiliation(s)
- Marion Steffensky
- NMI Naturwissenschaftliches und Medizinisches Institut, an der Universität Tübingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany
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Christensen C, Ambartsumian N, Gilestro G, Thomsen B, Comoglio P, Tamagnone L, Guldberg P, Lukanidin E. Proteolytic processing converts the repelling signal Sema3E into an inducer of invasive growth and lung metastasis. Cancer Res 2005; 65:6167-77. [PMID: 16024618 DOI: 10.1158/0008-5472.can-04-4309] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have previously shown that the expression of a semaphorin, known as a repelling cue in axon guidance, Sema3E, correlates with the ability to form lung metastasis in murine adenocarcinoma cell models. Now, besides providing evidence for the relevance of SEMA3E to human disease by showing that SEMA3E is frequently expressed in human cancer cell lines and solid tumors from breast cancer patients, we show biological activities of Sema3E, which support the implication of Sema3E in tumor progression and metastasis. In vivo, expression of Sema3E in mammary adenocarcinoma cells induces the ability to form experimental lung metastasis, and in vitro, the Sema3E protein exhibits both migration and growth promoting activity on endothelial cells and pheochromocytoma cells. This represents the first evidence of a metastasis-promoting function of a class 3 semaphorin, as this class of genes has hitherto been implicated in tumor biology only as tumor suppressors and negative regulators of growth. Moreover, we show that the full-size Sema3E protein is converted into a p61-Sema3E isoform due to furin-dependent processing, and by analyzing processing-deficient and truncated forms, we show that the generation of p61-Sema3E is required and sufficient for the function of Sema3E in lung metastasis, cell migration, invasive growth, and extracellular signal-regulated kinase 1/2 activation of endothelial cells. These findings suggest that certain breast cancer cells may increase their lung-colonizing ability by converting the growth repellent, Sema3E, into a growth attractant and point to a type of semaphorin signaling different from the conventional signaling induced by full-size dimeric class 3 semaphorins.
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Affiliation(s)
- Claus Christensen
- Institute of Cancer Biology, Department of Biostatistics and Electronic Data Processing, Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark.
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Ko JA, Gondo T, Inagaki S, Inui M. Requirement of the transmembrane semaphorin Sema4C for myogenic differentiation. FEBS Lett 2005; 579:2236-42. [PMID: 15811348 DOI: 10.1016/j.febslet.2005.03.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 03/03/2005] [Accepted: 03/03/2005] [Indexed: 12/28/2022]
Abstract
Semaphorins constitute a large family of signaling proteins that contribute to axonal guidance. Here we demonstrate that the transmembrane semaphorin Sema4C is up-regulated both in the early stage of differentiation of C2C12 mouse skeletal myoblasts into myotubes and during injury-induced muscle regeneration in vivo. Depletion of Sema4C in C2C12 cells resulted in marked attenuation of myotube formation. A fusion protein containing the extracellular Sema domain and a peptide corresponding to the intracellular COOH-terminal region of Sema4C each inhibited the differentiation of C2C12 cells. These findings indicate that Sema4C-mediated interaction among myoblasts plays an important role in terminal myogenic differentiation.
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Affiliation(s)
- Ji-Ae Ko
- Department of Pharmacology, Yamaguchi University School of Medicine, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan
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Gaillard S, Nasarre C, Gonthier B, Bagnard D. Mécanismes cellulaires et moléculaires de la croissance axonale. Rev Neurol (Paris) 2005; 161:153-72. [PMID: 15798515 DOI: 10.1016/s0035-3787(05)85019-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION During embryonic and post-natal development, numerous axonal connections are formed establishing a functional nervous system. Knowledge of the underlying molecular and cellular mechanisms controlling this phenomenon is improving. STATE OF THE ART In this review, we present the general principles of axon guidance together with the major families of guidance signals. This includes the tyrosine kinase receptors Eph and their ligands Ephrins, the netrins, the semaphorins, the slits and other major components of the extracellular matrix. These types of guidance signals share common functional properties leading to actin cytoskeleton remodelling. The direct or indirect interactions between the receptors of these guidance cues and actin modulators is the final step of the signalling cascade constituting the fundamental mechanism defining the orientation and extension of the axonal growth cone. These factors are involved in the formation of many, if not all, axonal projections for which they act as repulsive (inhibitory) or attractive (promoting) signals. PERSPECTIVES the knowledge of these mechanisms is particularly interesting since the inhibition of axonal outgrowth is considered to be one of the major obstacles to nerve regeneration in the central nervous system. Indeed, most of the guidance signals expressed during brain development are up-regulated in lesion sites where they contribute to the lack of nerve re-growth. Here, we present the nature of the mechanical barrier, the so called glial scar, and we describe the major inhibitory molecules preventing axonal extension. CONCLUSION the comprehension of the molecular mechanisms involved in axon growth and guidance represents a major advance towards the definition of novel therapeutic strategies improving nerve regeneration. The path to the clinical application of these molecular factors remains long. Nevertheless, the next decade will undoubtedly provide challenging data that will modify the current therapeutic approaches.
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Affiliation(s)
- S Gaillard
- INSERM U575, Physiopathologie du Système Nerveux, Groupe de Physiologie Moléculaire de la Régénération Nerveuse, 67084 Strasbourg
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Yu Q, Shen Y, Chatterjee B, Siegfried BH, Leatherbury L, Rosenthal J, Lucas JF, Wessels A, Spurney CF, Wu YJ, Kirby ML, Svenson K, Lo CW. ENU induced mutations causing congenital cardiovascular anomalies. Development 2004; 131:6211-23. [PMID: 15548583 DOI: 10.1242/dev.01543] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We used non-invasive high frequency ultrasound to screen N-ethyl-N-nitrosourea mutagenized mouse fetuses for congenital cardiovascular anomalies. We ultrasound scanned 7546 mouse fetuses from 262 mutagenized families, and identified 124 families with cardiovascular defects. Represented were most of the major congenital cardiovascular anomalies seen clinically. The ENU-induced mutations in several families were mapped using polymorphic microsatellite DNA markers. One family with forelimb anomalies and ventricular septal defects, phenotypes similar to Holt-Oram syndrome, and one family with transposition of the great arteries and heart situs anomalies were mapped to different regions of mouse chromosome 4. A third mutation causing persistent truncus arteriosus and craniofacial defects, phenotypes reminiscent of DiGeorge syndrome, was mapped to mouse chromosome 2. We note that mouse chromosomes 4 and 2 do not contain Tbx5 or Tbx1, genes previously linked to Holt-Oram and DiGeorge syndromes, respectively. In two other families, the ENU-induced mutation was identified--Sema3CL605P was associated with persistent truncus arteriosus with interrupted aortic arch, and the Gja1W45X connexin43 mutation caused conotruncal malformation and coronary aneurysms. Although our screen was designed as a recessive screen, a number of the mutations showed cardiovascular phenotypes in both heterozygote and homozygote animals. These studies show the efficacy of ENU mutagenesis and high-throughput ultrasound phenotyping in recovering mutations causing a wide spectrum of congenital heart defects. These ENU-induced mutations hold promise in yielding new insights into the genetic basis for human congenital heart disease.
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Affiliation(s)
- Qing Yu
- Laboratory of Developmental Biology, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8019, USA
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Itoh K, Cheng L, Kamei Y, Fushiki S, Kamiguchi H, Gutwein P, Stoeck A, Arnold B, Altevogt P, Lemmon V. Brain development in mice lacking L1-L1 homophilic adhesion. ACTA ACUST UNITED AC 2004; 165:145-54. [PMID: 15067019 PMCID: PMC2172083 DOI: 10.1083/jcb.200312107] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new mouse line has been produced in which the sixth Ig domain of the L1 cell adhesion molecule has been deleted. Despite the rather large deletion, L1 expression is preserved at normal levels. In vitro experiments showed that L1–L1 homophilic binding was lost, along with L1-α5β1 integrin binding. However, L1–neurocan and L1–neuropilin binding were preserved and sema3a responses were intact. Surprisingly, many of the axon guidance defects present in the L1 knockout mice, such as abnormal corticospinal tract and corpus callosum, were not observed. Nonetheless, when backcrossed on the C57BL/6 strain, a severe hydrocephalus was observed and after several generations, became an embryonic lethal. These results imply that L1 binding to L1, TAG-1, or F3, and L1-α5β1 integrin binding are not essential for normal development of a variety of axon pathways, and suggest that L1–L1 homophilic binding is important in the production of X-linked hydrocephalus.
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Affiliation(s)
- Kyoko Itoh
- Department of Neuroscience, Case Western Reserve University, Cleveland, OH 44106, USA
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Barton WA, Himanen JP, Antipenko A, Nikolov DB. Structures of Axon Guidance Molecules and their Neuronal Receptors. CELL SURFACE RECEPTORS 2004; 68:65-106. [PMID: 15500859 DOI: 10.1016/s0065-3233(04)68003-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- William A Barton
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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Love CA, Harlos K, Mavaddat N, Davis SJ, Stuart DI, Jones EY, Esnouf RM. The ligand-binding face of the semaphorins revealed by the high-resolution crystal structure of SEMA4D. Nat Struct Mol Biol 2003; 10:843-8. [PMID: 12958590 DOI: 10.1038/nsb977] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2003] [Accepted: 08/04/2003] [Indexed: 12/29/2022]
Abstract
Semaphorins, proteins characterized by an extracellular sema domain, regulate axon guidance, immune function and angiogenesis. The crystal structure of SEMA4D (residues 1-657) shows the sema topology to be a seven-bladed beta-propeller, revealing an unexpected homology with integrins. The sema beta-propeller contains a distinctive 77-residue insertion between beta-strands C and D of blade 5. Blade 7 is followed by a domain common to plexins, semaphorins and integrins (PSI domain), which forms a compact cysteine knot abutting the side of the propeller, and an Ig-like domain. The top face of the beta-propeller presents prominent loops characteristic of semaphorins. In addition to limited contact between the Ig-like domains, the homodimer is stabilized through extensive interactions between the top faces in a sector of the beta-propeller used for heterodimerization in integrins. This face of the propeller also mediates ligand binding in integrins, and functional data for semaphorin-receptor interactions map to the equivalent surface.
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Affiliation(s)
- Christopher A Love
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
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Antipenko A, Himanen JP, van Leyen K, Nardi-Dei V, Lesniak J, Barton WA, Rajashankar KR, Lu M, Hoemme C, Püschel AW, Nikolov DB. Structure of the semaphorin-3A receptor binding module. Neuron 2003; 39:589-98. [PMID: 12925274 DOI: 10.1016/s0896-6273(03)00502-6] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The semaphorins are a large group of extracellular proteins involved in a variety of processes during development, including neuronal migration and axon guidance. Their distinctive feature is a conserved 500 amino acid semaphorin domain, a ligand-receptor interaction module also present in plexins and scatter-factor receptors. We report the crystal structure of a secreted 65 kDa form of Semaphorin-3A (Sema3A), containing the full semaphorin domain. Unexpectedly, the semaphorin fold is a variation of the beta propeller topology. Analysis of the Sema3A structure and structure-based mutagenesis data identify the neuropilin binding site and suggest a potential plexin interaction site. Based on the structure, we present a model for the initiation of semaphorin signaling and discuss potential similarities with the signaling mechanisms of other beta propeller cell surface receptors, such as integrins and the LDL receptor.
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Affiliation(s)
- Alexander Antipenko
- Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
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Oster SF, Bodeker MO, He F, Sretavan DW. Invariant Sema5A inhibition serves an ensheathing function during optic nerve development. Development 2003; 130:775-84. [PMID: 12506007 DOI: 10.1242/dev.00299] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Retinal axon pathfinding from the retina into the optic nerve involves the growth promoting axon guidance molecules L1, laminin and netrin 1, each of which governs axon behavior at specific regions along the retinal pathway. In identifying additional molecules regulating this process during embryonic mouse development, we found that transmembrane Semaphorin5A mRNA and protein was specifically expressed in neuroepithelial cells surrounding retinal axons at the optic disc and along the optic nerve. Given that growth cone responses to a specific guidance molecule can be altered by co-exposure to a second guidance cue, we examined whether retinal axon responses to Sema5A were modulated by other guidance signals axons encountered along the retinal pathway. In growth cone collapse, substratum choice and neurite outgrowth assays, Sema5A triggered an invariant inhibitory response in the context of L1, laminin, or netrin 1 signaling, suggesting that Sema5A inhibited retinal axons throughout their course at the optic disc and nerve. Antibody-perturbation studies in living embryo preparations showed that blocking of Sema5A function led to retinal axons straying out of the optic nerve bundle, indicating that Sema5A normally helped ensheath the retinal pathway. Thus, development of some CNS nerves requires inhibitory sheaths to maintain integrity. Furthermore, this function is accomplished using molecules such as Sema5A that exhibit conserved inhibitory responses in the presence of co-impinging signals from multiple families of guidance molecules.
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Affiliation(s)
- Stephen F Oster
- Department of Ophthalmology, Medical Scientist Training Program, University of California San Francisco, CA 94143, USA
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Abstract
The NG2 chondroitin sulfate proteoglycan, an integral membrane proteoglycan, inhibits axon growth from cerebellar granule neurons and dorsal root ganglia (DRG) neurons in vitro. The extracellular domain of the NG2 core protein contains three subdomains: an N-terminal globular domain (domain 1), a central extended domain that has the sites for glycosaminoglycan (GAG) attachment (domain 2), and a juxtamembrane domain (domain 3). Here, we used domain-specific fusion proteins and antibodies to map the inhibitory activity within the NG2 core protein. Fusion proteins encoding domain 1 (D1-Fc) or domain 3 (D3-Fc) of NG2 inhibited axon growth from cerebellar granule neurons when the proteins were substrate-bound. These proteins also induced growth cone collapse from newborn DRG neurons when added to the culture medium. Domain 2 only inhibited axon growth when the GAG chains were present. Neutralizing antibodies directed against domain 1 or 3 blocked completely the inhibition from substrates coated with D1-Fc or D3-Fc. When the entire extracellular domain of NG2 was used as a substrate, however, both neutralizing antibodies were needed to reverse completely the inhibition. When NG2 was expressed on the surface of HEK293 cells, the neutralizing anti-D1 antibody was sufficient to block the inhibition, whereas the anti-D3 antibody had no effect. These results suggest that domains 1 and 3 of NG2 can inhibit neurite growth independently. These inhibitory domains may be differentially exposed depending on whether NG2 is presented as an integral membrane protein or as a secreted protein associated with the extracellular matrix.
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Abstract
The immune system and the nervous system have distinct roles in maintaining physiological homeostasis. These independent systems, however, influence each other while sharing common resources, including the cytokines and members of the immunoglobulin superfamily. Semaphorins are one of these shared molecular families that are biologically active in both systems. Although semaphorins were originally identified as axon guidance factors functioning in the nervous system, recent studies have uncovered additional immunological functions. For example, ligand-receptor systems distinct from those characterized in the nervous system govern class IV semaphorin, CD100/Sema4D and Sema4A activity in immune responses. This review provides an overview of the currently emerging immunoregulatory functions of "Immuno-semaphorins."
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Affiliation(s)
- Atsushi Kumanogoh
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Abstract
This review of ECM molecules shows quite clearly the function of the ECM in development but more importantly in the mature CNS after injury. Most of the proteoglycans, especially the large CS-PGs, are able to inhibit neurite outgrowth and in vivo experiments are now in progress to specifically inhibit these important molecules. The nature of growth promoter ECM molecules in the CNS after injury, either within or distant from the injury is now becoming better appreciated and we suggest that the laminin family should be important targets for exploration. Indeed, a better understanding of the interaction of laminin with those ECM components that are inhibitory is a clear goal for the future. Our ultimate aim must be to change the balance of factors at lesion sites to allow the more permissive environment after CNS injury to predominate.
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Affiliation(s)
- Barbara Grimpe
- Case Western Reserve University, School of Medicine, Department of Neurosciences, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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Bagril A, Tessier-Lavigne M. Neuropilins as semaphorin receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002. [DOI: 10.1007/978-1-4615-0119-0_2] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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