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Chhabra KH, Bathina S, Faniyan TS, Samuel DJ, Raza MU, de Souza Cordeiro LM, Viana Di Prisco G, Atwood BK, Robles J, Bainbridge L, Davis A. ADGRL1 is a glucose receptor involved in mediating energy and glucose homeostasis. Diabetologia 2024; 67:170-189. [PMID: 37712955 PMCID: PMC10709246 DOI: 10.1007/s00125-023-06010-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/07/2023] [Indexed: 09/16/2023]
Abstract
AIMS/HYPOTHESIS The brain is a major consumer of glucose as an energy source and regulates systemic glucose as well as energy balance. Although glucose transporters such as GLUT2 and sodium-glucose cotransporter 2 (SGLT2) are known to regulate glucose homeostasis and metabolism, the identity of a receptor that binds glucose to activate glucose signalling pathways in the brain is unknown. In this study, we aimed to discover a glucose receptor in the mouse hypothalamus. METHODS Here we used a high molecular mass glucose-biotin polymer to enrich glucose-bound mouse hypothalamic neurons through cell-based affinity chromatography. We then subjected the enriched neurons to proteomic analyses and identified adhesion G-protein coupled receptor 1 (ADGRL1) as a top candidate for a glucose receptor. We validated glucose-ADGRL1 interactions using CHO cells stably expressing human ADGRL1 and ligand-receptor binding assays. We generated and determined the phenotype of global Adgrl1-knockout mice and hypothalamus-specific Adgrl1-deficient mice. We measured the variables related to glucose and energy homeostasis in these mice. We also generated an Adgrl1Cre mouse model to investigate the role of ADGRL1 in sensing glucose using electrophysiology. RESULTS Adgrl1 is highly expressed in the ventromedial nucleus of the hypothalamus (VMH) in mice. Lack of Adgrl1 in the VMH in mice caused fasting hyperinsulinaemia, enhanced glucose-stimulated insulin secretion and insulin resistance. In addition, the Adgrl1-deficient mice had impaired feeding responses to glucose and fasting coupled with abnormal glucose sensing and decreased physical activity before development of obesity and hyperglycaemia. In female mice, ovariectomy was necessary to reveal the contribution of ADGRL1 to energy and glucose homeostasis. CONCLUSIONS/INTERPRETATION Altogether, our findings demonstrate that ADGRL1 binds glucose and is involved in energy as well as glucose homeostasis in a sex-dependent manner. Targeting ADGRL1 may introduce a new class of drugs for the treatment of type 2 diabetes and obesity.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Siresha Bathina
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Tumininu S Faniyan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Dennis J Samuel
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Muhammad Ummear Raza
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Leticia Maria de Souza Cordeiro
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Gonzalo Viana Di Prisco
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brady K Atwood
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jorge Robles
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Lauren Bainbridge
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Autumn Davis
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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2
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Osaka J, Yasuda H, Watanuki Y, Kato Y, Nitta Y, Sugie A, Sato M, Suzuki T. Identification of genes regulating stimulus-dependent synaptic assembly in Drosophila using an automated synapse quantification system. Genes Genet Syst 2023; 97:297-309. [PMID: 36878557 DOI: 10.1266/ggs.22-00114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
Neural activity-dependent synaptic plasticity is an important physiological phenomenon underlying environmental adaptation, memory and learning. However, its molecular basis, especially in presynaptic neurons, is not well understood. Previous studies have shown that the number of presynaptic active zones in the Drosophila melanogaster photoreceptor R8 is reversibly changed in an activity-dependent manner. During reversible synaptic changes, both synaptic disassembly and assembly processes were observed. Although we have established a paradigm for screening molecules involved in synaptic stability and several genes have been identified, genes involved in stimulus-dependent synaptic assembly are still elusive. Therefore, the aim of this study was to identify genes regulating stimulus-dependent synaptic assembly in Drosophila using an automated synapse quantification system. To this end, we performed RNAi screening against 300 memory-defective, synapse-related or transmembrane molecules in photoreceptor R8 neurons. Candidate genes were narrowed down to 27 genes in the first screen using presynaptic protein aggregation as a sign of synaptic disassembly. In the second screen, we directly quantified the decreasing synapse number using a GFP-tagged presynaptic protein marker. We utilized custom-made image analysis software, which automatically locates synapses and counts their number along individual R8 axons, and identified cirl as a candidate gene responsible for synaptic assembly. Finally, we present a new model of stimulus-dependent synaptic assembly through the interaction of cirl and its possible ligand, ten-a. This study demonstrates the feasibility of using the automated synapse quantification system to explore activity-dependent synaptic plasticity in Drosophila R8 photoreceptors in order to identify molecules involved in stimulus-dependent synaptic assembly.
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Affiliation(s)
- Jiro Osaka
- School of Life Science and Technology, Tokyo Institute of Technology
| | - Haruka Yasuda
- School of Life Science and Technology, Tokyo Institute of Technology
| | - Yusuke Watanuki
- School of Life Science and Technology, Tokyo Institute of Technology
| | - Yuya Kato
- School of Life Science and Technology, Tokyo Institute of Technology
| | - Yohei Nitta
- Brain Research Institute, Niigata University
| | | | - Makoto Sato
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa University.,Graduate School of Frontier Science Initiative, Kanazawa University
| | - Takashi Suzuki
- School of Life Science and Technology, Tokyo Institute of Technology
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3
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Zhou K, Luo W, Liu T, Ni Y, Qin Z. Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications. Toxins (Basel) 2022; 15:18. [PMID: 36668838 PMCID: PMC9865788 DOI: 10.3390/toxins15010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotoxins generally inhibit or promote the release of neurotransmitters or bind to receptors that are located in the pre- or post-synaptic membranes, thereby affecting physiological functions of synapses and affecting biological processes. With more and more research on the toxins of various origins, many neurotoxins are now widely used in clinical treatment and have demonstrated good therapeutic outcomes. This review summarizes the structural properties and potential pharmacological effects of neurotoxins acting on different components of the synapse, as well as their important clinical applications, thus could be a useful reference for researchers and clinicians in the study of neurotoxins.
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Affiliation(s)
- Kunming Zhou
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong 226019, China
| | - Yong Ni
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zhenghong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
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ADGRL1 haploinsufficiency causes a variable spectrum of neurodevelopmental disorders in humans and alters synaptic activity and behavior in a mouse model. Am J Hum Genet 2022; 109:1436-1457. [PMID: 35907405 PMCID: PMC9388395 DOI: 10.1016/j.ajhg.2022.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/22/2022] [Indexed: 02/06/2023] Open
Abstract
ADGRL1 (latrophilin 1), a well-characterized adhesion G protein-coupled receptor, has been implicated in synaptic development, maturation, and activity. However, the role of ADGRL1 in human disease has been elusive. Here, we describe ten individuals with variable neurodevelopmental features including developmental delay, intellectual disability, attention deficit hyperactivity and autism spectrum disorders, and epilepsy, all heterozygous for variants in ADGRL1. In vitro, human ADGRL1 variants expressed in neuroblastoma cells showed faulty ligand-induced regulation of intracellular Ca2+ influx, consistent with haploinsufficiency. In vivo, Adgrl1 was knocked out in mice and studied on two genetic backgrounds. On a non-permissive background, mice carrying a heterozygous Adgrl1 null allele exhibited neurological and developmental abnormalities, while homozygous mice were non-viable. On a permissive background, knockout animals were also born at sub-Mendelian ratios, but many Adgrl1 null mice survived gestation and reached adulthood. Adgrl1-/- mice demonstrated stereotypic behaviors, sexual dysfunction, bimodal extremes of locomotion, augmented startle reflex, and attenuated pre-pulse inhibition, which responded to risperidone. Ex vivo synaptic preparations displayed increased spontaneous exocytosis of dopamine, acetylcholine, and glutamate, but Adgrl1-/- neurons formed synapses in vitro poorly. Overall, our findings demonstrate that ADGRL1 haploinsufficiency leads to consistent developmental, neurological, and behavioral abnormalities in mice and humans.
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Thwarting of Lphn3 Functions in Cell Motility and Signaling by Cancer-Related GAIN Domain Somatic Mutations. Cells 2022; 11:cells11121913. [PMID: 35741042 PMCID: PMC9221416 DOI: 10.3390/cells11121913] [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: 04/28/2022] [Revised: 05/21/2022] [Accepted: 05/31/2022] [Indexed: 11/24/2022] Open
Abstract
Cancer progression relies on cellular transition states accompanied by changes in the functionality of adhesion molecules. The gene for adhesion G protein-coupled receptor latrophilin-3 (aGPCR Lphn3 or ADGRL3) is targeted by tumor-specific somatic mutations predominantly affecting the conserved GAIN domain where most aGPCRs are cleaved. However, it is unclear how these GAIN domain-altering mutations impact Lphn3 function. Here, we studied Lphn3 cancer-related mutations as a proxy for revealing unknown GAIN domain functions. We found that while intra-GAIN cleavage efficiency was unaltered, most mutations produced a ligand-specific impairment of Lphn3 intercellular adhesion profile paralleled by an increase in cell-matrix actin-dependent contact structures for cells expressing the select S810L mutation. Aberrant remodeling of the intermediate filament vimentin, which was found to coincide with Lphn3-induced modification of nuclear morphology, had less impact on the nuclei of S810L expressing cells. Notoriously, receptor signaling through G13 protein was deficient for all variants bearing non-homologous amino acid substitutions, including the S810L variant. Analysis of cell migration paradigms revealed a non-cell-autonomous impairment in collective cell migration indistinctly of Lphn3 or its cancer-related variants expression, while cell-autonomous motility was potentiated in the presence of Lphn3, but this effect was abolished in S810L GAIN mutant-expressing cells. These data identify the GAIN domain as an important regulator of Lphn3-dependent cell motility, thus furthering our understanding of cellular and molecular events linking Lphn3 genetic somatic mutations to cancer-relevant pathogenesis mechanisms.
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Lin HH, Ng KF, Chen TC, Tseng WY. Ligands and Beyond: Mechanosensitive Adhesion GPCRs. Pharmaceuticals (Basel) 2022; 15:ph15020219. [PMID: 35215331 PMCID: PMC8878244 DOI: 10.3390/ph15020219] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023] Open
Abstract
Cells respond to diverse types of mechanical stimuli using a wide range of plasma membrane-associated mechanosensitive receptors to convert extracellular mechanical cues into intracellular signaling. G protein-coupled receptors (GPCRs) represent the largest cell surface protein superfamily that function as versatile sensors for a broad spectrum of bio/chemical messages. In recent years, accumulating evidence has shown that GPCRs can also engage in mechano-transduction. According to the GRAFS classification system of GPCRs, adhesion GPCRs (aGPCRs) constitute the second largest GPCR subfamily with a unique modular protein architecture and post-translational modification that are well adapted for mechanosensory functions. Here, we present a critical review of current evidence on mechanosensitive aGPCRs.
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Affiliation(s)
- Hsi-Hsien Lin
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Anatomic Pathology, Chang Gung Memorial Hospital-Linkou, Taoyuan 33305, Taiwan; (K.-F.N.); (T.-C.C.)
- Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital-Keelung, Keelung 20401, Taiwan
- Correspondence: (H.-H.L.); (W.-Y.T.)
| | - Kwai-Fong Ng
- Department of Anatomic Pathology, Chang Gung Memorial Hospital-Linkou, Taoyuan 33305, Taiwan; (K.-F.N.); (T.-C.C.)
| | - Tse-Ching Chen
- Department of Anatomic Pathology, Chang Gung Memorial Hospital-Linkou, Taoyuan 33305, Taiwan; (K.-F.N.); (T.-C.C.)
| | - Wen-Yi Tseng
- Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital-Keelung, Keelung 20401, Taiwan
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Correspondence: (H.-H.L.); (W.-Y.T.)
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7
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Affiliation(s)
| | - Tobias Langenhan
- Rudolf Schönheimer Institute of Biochemistry Division of General Biochemistry Medical Faculty Leipzig University Leipzig Germany
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8
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Chen M, Blum D, Engelhard L, Raunser S, Wagner R, Gatsogiannis C. Molecular architecture of black widow spider neurotoxins. Nat Commun 2021; 12:6956. [PMID: 34845192 PMCID: PMC8630228 DOI: 10.1038/s41467-021-26562-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 10/11/2021] [Indexed: 12/14/2022] Open
Abstract
Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α-latrotoxin (α-LTX)), five specialized on insects (α, β, γ, δ, ε- latroinsectotoxins (LITs), and one on crustaceans (α-latrocrustatoxin (α-LCT)). LaTXs bind to specific receptors on the surface of neuronal cells, inducing the release of neurotransmitters either by directly stimulating exocytosis or by forming Ca2+-conductive tetrameric pores in the membrane. Despite extensive studies in the past decades, a high-resolution structure of a LaTX is not yet available and the precise mechanism of LaTX action remains unclear. Here, we report cryoEM structures of the α-LCT monomer and the δ-LIT dimer. The structures reveal that LaTXs are organized in four domains. A C-terminal domain of ankyrin-like repeats shields a central membrane insertion domain of six parallel α-helices. Both domains are flexibly linked via an N-terminal α-helical domain and a small β-sheet domain. A comparison between the structures suggests that oligomerization involves major conformational changes in LaTXs with longer C-terminal domains. Based on our data we propose a cyclic mechanism of oligomerization, taking place prior membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca2+ ions and allow calcium flux at negative membrane potentials. Our comparative analysis between α-LCT and δ-LIT provides first crucial insights towards understanding the molecular mechanism of the LaTX family. The venom of Latrodectus spiders contains seven Latrotoxins (LaTXs), among them α-latrocrustatoxin (LCT) and δ- latroinsectotoxins δ-LIT. LaTXs bind to specific receptors on the surface of neuronal cells and target the molecular exocytosis machinery. Here, the authors present the cryo-EM structure of the α-LCT monomer and the δ-LIT dimer, which reveal that LaTXs are organized in four domains and they discuss the potential oligomerisation mechanism that takes place before LaTXs membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca2+ ions.
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Affiliation(s)
- Minghao Chen
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, 48149, Münster, Germany.,Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Daniel Blum
- MOLIFE Research Center, Jacobs University Bremen, 28759, Bremen, Germany
| | - Lena Engelhard
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany
| | - Richard Wagner
- MOLIFE Research Center, Jacobs University Bremen, 28759, Bremen, Germany
| | - Christos Gatsogiannis
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, 48149, Münster, Germany. .,Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227, Dortmund, Germany.
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9
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Development of Multidrug Resistance in Acute Myeloid Leukemia Is Associated with Alterations of the LPHN1/GAL-9/TIM-3 Signaling Pathway. Cancers (Basel) 2021; 13:cancers13143629. [PMID: 34298843 PMCID: PMC8304048 DOI: 10.3390/cancers13143629] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/11/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023] Open
Abstract
P-glycoprotein (known as ABCB1 transporter) expression in myeloid blasts of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) leads to the commonly observed multidrug resistance. Overexpression of latrophilin-1 was detected in leukemic cells from AML patients. In a previous study, we showed that ABCB1 overexpression is associated with decreased latrophilin-1 expression in MOLM-13/VCR and SKM-1/VCR AML cell variants derived from MOLM-13 and SKM-1 cells by vincristine selection/adaptation. In the present study, we found that if ABCB1 overexpression occurs in myeloid blasts of newly diagnosed MDS patients, latrophilin-1 expression is attenuated. Latrophilin-1 may initiate TIM-3- and galectin-9-mediated immune escape. We demonstrated changes in the expression of both proteins by comparing ABCB1-positive cell variants (MOLM-13/VCR, SKM-1/VCR) with their ABCB1-negative counterparts. Galectin-9 was present in our cell lines in eight protein isoforms for which we identified the respective transcription variants resulting from alternative splicing, and we verified their structure by sequencing. The isoform profile of galectin-9 was different between ABCB1-positive and ABCB1-negative cell variants. The interaction partner of galectin-9 is CD44, and its expression was altered in the ABCB1-positive variants MOLM-13/VCR and SKM-1/VCR compared to their ABCB1-negative counterparts.
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10
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Kaczmarek I, Suchý T, Prömel S, Schöneberg T, Liebscher I, Thor D. The relevance of adhesion G protein-coupled receptors in metabolic functions. Biol Chem 2021; 403:195-209. [PMID: 34218541 DOI: 10.1515/hsz-2021-0146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/08/2021] [Indexed: 01/06/2023]
Abstract
G protein-coupled receptors (GPCRs) modulate a variety of physiological functions and have been proven to be outstanding drug targets. However, approximately one-third of all non-olfactory GPCRs are still orphans in respect to their signal transduction and physiological functions. Receptors of the class of Adhesion GPCRs (aGPCRs) are among these orphan receptors. They are characterized by unique features in their structure and tissue-specific expression, which yields them interesting candidates for deorphanization and testing as potential therapeutic targets. Capable of G-protein coupling and non-G protein-mediated function, aGPCRs may extend our repertoire of influencing physiological function. Besides their described significance in the immune and central nervous systems, growing evidence indicates a high importance of these receptors in metabolic tissue. RNAseq analyses revealed high expression of several aGPCRs in pancreatic islets, adipose tissue, liver, and intestine but also in neurons governing food intake. In this review, we focus on aGPCRs and their function in regulating metabolic pathways. Based on current knowledge, this receptor class represents high potential for future pharmacological approaches addressing obesity and other metabolic diseases.
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Affiliation(s)
- Isabell Kaczmarek
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
| | - Tomáš Suchý
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
| | - Simone Prömel
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
- Institute of Cell Biology, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
| | - Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, D-04103 Leipzig, Germany
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Regan SL, Williams MT, Vorhees CV. Latrophilin-3 disruption: Effects on brain and behavior. Neurosci Biobehav Rev 2021; 127:619-629. [PMID: 34022279 DOI: 10.1016/j.neubiorev.2021.04.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 12/22/2022]
Abstract
Latrophilin-3 (LPHN3), a G-protein-coupled receptor belonging to the adhesion subfamily, is a regulator of synaptic function and maintenance in brain regions that mediate locomotor activity, attention, and memory for location and path. Variants of LPHN3 are associated with increased risk for attention deficit hyperactivity disorder (ADHD) in some patients. Here we review the role of LPHN3 in the central nervous system (CNS). We describe synaptic localization of LPHN3, its trans-synaptic binding partners, links to neurodevelopmental disorders, animal models of Lphn3 disruption in different species, and evidence that LPHN3 is involved in cognition as well as activity and attention. The evidence shows that LPHN3 plays a more significant role in neuroplasticity than previously appreciated.
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Affiliation(s)
- Samantha L Regan
- Neuroscience Graduate Program, University of Cincinnati, Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Michael T Williams
- Neuroscience Graduate Program, University of Cincinnati, Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA
| | - Charles V Vorhees
- Neuroscience Graduate Program, University of Cincinnati, Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, OH, 45229, USA.
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12
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Føns S, Ledsgaard L, Nikolaev MV, Vassilevski AA, Sørensen CV, Chevalier MK, Fiebig M, Laustsen AH. Discovery of a Recombinant Human Monoclonal Immunoglobulin G Antibody Against α-Latrotoxin From the Mediterranean Black Widow Spider ( Latrodectus tredecimguttatus). Front Immunol 2020; 11:587825. [PMID: 33262768 PMCID: PMC7688514 DOI: 10.3389/fimmu.2020.587825] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/19/2020] [Indexed: 12/26/2022] Open
Abstract
Widow spiders are among the few spider species worldwide that can cause serious envenoming in humans. The clinical syndrome resulting from Latrodectus spp. envenoming is called latrodectism and characterized by pain (local or regional) associated with diaphoresis and nonspecific systemic effects. The syndrome is caused by α-latrotoxin, a ~130 kDa neurotoxin that induces massive neurotransmitter release. Due to this function, α-latrotoxin has played a fundamental role as a tool in the study of neuroexocytosis. Nevertheless, some questions concerning its mode of action remain unresolved today. The diagnosis of latrodectism is purely clinical, combined with the patient's history of spider bite, as no analytical assays exist to detect widow spider venom. By utilizing antibody phage display technology, we here report the discovery of the first recombinant human monoclonal immunoglobulin G antibody (TPL0020_02_G9) that binds α-latrotoxin from the Mediterranean black widow spider (Latrodectus tredecimguttatus) and show neutralization efficacy ex vivo. Such antibody can be used as an affinity reagent for research and diagnostic purposes, providing researchers with a novel tool for more sophisticated experimentation and analysis. Moreover, it may also find therapeutic application in future.
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Affiliation(s)
- Sofie Føns
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Line Ledsgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Maxim V. Nikolaev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Alexander A. Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Christoffer V. Sørensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Manon K. Chevalier
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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13
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Li J, Xie Y, Cornelius S, Jiang X, Sando R, Kordon SP, Pan M, Leon K, Südhof TC, Zhao M, Araç D. Alternative splicing controls teneurin-latrophilin interaction and synapse specificity by a shape-shifting mechanism. Nat Commun 2020; 11:2140. [PMID: 32358586 PMCID: PMC7195488 DOI: 10.1038/s41467-020-16029-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/06/2020] [Indexed: 02/07/2023] Open
Abstract
The trans-synaptic interaction of the cell-adhesion molecules teneurins (TENs) with latrophilins (LPHNs/ADGRLs) promotes excitatory synapse formation when LPHNs simultaneously interact with FLRTs. Insertion of a short alternatively-spliced region within TENs abolishes the TEN-LPHN interaction and switches TEN function to specify inhibitory synapses. How alternative-splicing regulates TEN-LPHN interaction remains unclear. Here, we report the 2.9 Å resolution cryo-EM structure of the TEN2-LPHN3 complex, and describe the trimeric TEN2-LPHN3-FLRT3 complex. The structure reveals that the N-terminal lectin domain of LPHN3 binds to the TEN2 barrel at a site far away from the alternatively spliced region. Alternative-splicing regulates the TEN2-LPHN3 interaction by hindering access to the LPHN-binding surface rather than altering it. Strikingly, mutagenesis of the LPHN-binding surface of TEN2 abolishes the LPHN3 interaction and impairs excitatory but not inhibitory synapse formation. These results suggest that a multi-level coincident binding mechanism mediated by a cryptic adhesion complex between TENs and LPHNs regulates synapse specificity. The trans-synaptic interaction of the cell-adhesion molecules teneurins (TENs) with latrophilins (LPHNs) promotes excitatory synapse formation. Here authors report the high resolution cryo-EM structure of the TEN2-LPHN3 complex, describe the trimeric TEN2-LPHN3-FLRT3 complex and show how alternative-splicing regulates the TEN2-LPHN3 interaction.
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Affiliation(s)
- Jingxian Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA.,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, 60637, USA
| | - Yuan Xie
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Shaleeka Cornelius
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Xian Jiang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Richard Sando
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Szymon P Kordon
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA.,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, 60637, USA
| | - Man Pan
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Katherine Leon
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA.,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, 60637, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Minglei Zhao
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA.
| | - Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, 60637, USA. .,Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, 60637, USA.
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14
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Del Toro D, Carrasquero-Ordaz MA, Chu A, Ruff T, Shahin M, Jackson VA, Chavent M, Berbeira-Santana M, Seyit-Bremer G, Brignani S, Kaufmann R, Lowe E, Klein R, Seiradake E. Structural Basis of Teneurin-Latrophilin Interaction in Repulsive Guidance of Migrating Neurons. Cell 2020; 180:323-339.e19. [PMID: 31928845 PMCID: PMC6978801 DOI: 10.1016/j.cell.2019.12.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/15/2019] [Accepted: 12/11/2019] [Indexed: 02/07/2023]
Abstract
Teneurins are ancient metazoan cell adhesion receptors that control brain development and neuronal wiring in higher animals. The extracellular C terminus binds the adhesion GPCR Latrophilin, forming a trans-cellular complex with synaptogenic functions. However, Teneurins, Latrophilins, and FLRT proteins are also expressed during murine cortical cell migration at earlier developmental stages. Here, we present crystal structures of Teneurin-Latrophilin complexes that reveal how the lectin and olfactomedin domains of Latrophilin bind across a spiraling beta-barrel domain of Teneurin, the YD shell. We couple structure-based protein engineering to biophysical analysis, cell migration assays, and in utero electroporation experiments to probe the importance of the interaction in cortical neuron migration. We show that binding of Latrophilins to Teneurins and FLRTs directs the migration of neurons using a contact repulsion-dependent mechanism. The effect is observed with cell bodies and small neurites rather than their processes. The results exemplify how a structure-encoded synaptogenic protein complex is also used for repulsive cell guidance. Crystal structures reveal binding site for Latrophilin on the Teneurin YD shell A ternary Latrophilin-Teneurin-FLRT complex forms in vitro and in vivo Latrophilin controls cortical migration by binding to Teneurins and FLRTs Latrophilin elicits repulsion of cortical cell bodies/small neurites but not axons
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Affiliation(s)
- Daniel Del Toro
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried 82152, Germany; Department of Biological Sciences, Institute of Neurosciences, IDIBAPS, CIBERNED, University of Barcelona, Barcelona, Spain
| | | | - Amy Chu
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK
| | - Tobias Ruff
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Meriam Shahin
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK
| | - Verity A Jackson
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK
| | | | | | - Goenuel Seyit-Bremer
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Sara Brignani
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried 82152, Germany
| | - Rainer Kaufmann
- Center for Structural Systems Biology, University of Hamburg, Hamburg 22607, Germany; Department of Physics, University of Hamburg, Hamburg 20355, Germany
| | - Edward Lowe
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK
| | - Rüdiger Klein
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried 82152, Germany.
| | - Elena Seiradake
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK.
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15
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Dunn HA, Orlandi C, Martemyanov KA. Beyond the Ligand: Extracellular and Transcellular G Protein-Coupled Receptor Complexes in Physiology and Pharmacology. Pharmacol Rev 2019; 71:503-519. [PMID: 31515243 DOI: 10.1124/pr.119.018044] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
G protein-coupled receptors (GPCRs) remain one of the most successful targets of U.S. Food and Drug Administration-approved drugs. GPCR research has predominantly focused on the characterization of the intracellular interactome's contribution to GPCR function and pharmacology. However, emerging evidence uncovers a new dimension in the biology of GPCRs involving their extracellular and transcellular interactions that critically impact GPCR function and pharmacology. The seminal examples include a variety of adhesion GPCRs, such as ADGRLs/latrophilins, ADGRBs/brain angiogenesis inhibitors, ADGRG1/GPR56, ADGRG6/GPR126, ADGRE5/CD97, and ADGRC3/CELSR3. However, recent advances have indicated that class C GPCRs that contain large extracellular domains, including group III metabotropic glutamate receptors (mGluR4, mGluR6, mGluR7, mGluR8), γ-aminobutyric acid receptors, and orphans GPR158 and GPR179, can also participate in this form of transcellular regulation. In this review, we will focus on a variety of identified extracellular and transcellular GPCR-interacting partners, including teneurins, neurexins, integrins, fibronectin leucine-rich transmembranes, contactin-6, neuroligin, laminins, collagens, major prion protein, amyloid precursor protein, complement C1q-likes, stabilin-2, pikachurin, dystroglycan, complement decay-accelerating factor CD55, cluster of differentiation CD36 and CD90, extracellular leucine-rich repeat and fibronectin type III domain containing 1, and leucine-rich repeat, immunoglobulin-like domain and transmembrane domains. We provide an account on the diversity of extracellular and transcellular GPCR complexes and their contribution to key cellular and physiologic processes, including cell migration, axon guidance, cellular and synaptic adhesion, and synaptogenesis. Furthermore, we discuss models and mechanisms by which extracellular GPCR assemblies may regulate communication at cellular junctions. SIGNIFICANCE STATEMENT: G protein-coupled receptors (GPCRs) continue to be the prominent focus of pharmacological intervention for a variety of human pathologies. Although the majority of GPCR research has focused on the intracellular interactome, recent advancements have identified an extracellular dimension of GPCR modulation that alters accepted pharmacological principles of GPCRs. Herein, we describe known endogenous allosteric modulators acting on GPCRs both in cis and in trans.
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Affiliation(s)
- Henry A Dunn
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
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16
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Morgan RK, Anderson GR, Araç D, Aust G, Balenga N, Boucard A, Bridges JP, Engel FB, Formstone CJ, Glitsch MD, Gray RS, Hall RA, Hsiao CC, Kim HY, Knierim AB, Kusuluri DK, Leon K, Liebscher I, Piao X, Prömel S, Scholz N, Srivastava S, Thor D, Tolias KF, Ushkaryov YA, Vallon M, Van Meir EG, Vanhollebeke B, Wolfrum U, Wright KM, Monk KR, Mogha A. The expanding functional roles and signaling mechanisms of adhesion G protein-coupled receptors. Ann N Y Acad Sci 2019; 1456:5-25. [PMID: 31168816 PMCID: PMC7891679 DOI: 10.1111/nyas.14094] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/21/2019] [Indexed: 12/13/2022]
Abstract
The adhesion class of G protein-coupled receptors (GPCRs) is the second largest family of GPCRs (33 members in humans). Adhesion GPCRs (aGPCRs) are defined by a large extracellular N-terminal region that is linked to a C-terminal seven transmembrane (7TM) domain via a GPCR-autoproteolysis inducing (GAIN) domain containing a GPCR proteolytic site (GPS). Most aGPCRs undergo autoproteolysis at the GPS motif, but the cleaved fragments stay closely associated, with the N-terminal fragment (NTF) bound to the 7TM of the C-terminal fragment (CTF). The NTFs of most aGPCRs contain domains known to be involved in cell-cell adhesion, while the CTFs are involved in classical G protein signaling, as well as other intracellular signaling. In this workshop report, we review the most recent findings on the biology, signaling mechanisms, and physiological functions of aGPCRs.
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Affiliation(s)
- Rory K. Morgan
- Vollum Institute, Oregon Health & Science University, Portland, Oregon
| | - Garret R. Anderson
- Department of Molecular, Cell and Systems Biology, University of California – Riverside, Riverside, California
| | - Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - Gabriela Aust
- Research Laboratories, Department of Surgery, Leipzig University, Leipzig, Germany
| | - Nariman Balenga
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Program in Molecular and Structural Biology, Marlene and Stewart Greenebaum NCI Comprehensive Cancer Center, Baltimore, Maryland
| | - Antony Boucard
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, México
| | - James P. Bridges
- Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, Ohio
- Perinatal Institute, Section of Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - Felix B. Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Caroline J. Formstone
- Centre for Developmental Neurobiology, Guys Campus, Kings College London, London, UK
- Department of Biological and Environmental Sciences, College Lane Campus, University of Hertfordshire, Hatfield, UK
| | - Maike D. Glitsch
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Ryan S. Gray
- Department of Pediatrics, University of Texas at Austin, Dell Medical School, Austin, Texas
| | - Randy A. Hall
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia
| | - Cheng-Chih Hsiao
- Department of Experimental Immunology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Hee-Yong Kim
- Laboratory of Molecular Signaling, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Alexander B. Knierim
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Deva Krupakar Kusuluri
- Institute of Molecular Physiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Katherine Leon
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Xianhua Piao
- Newborn Brain Research Institute, Department of Pediatrics, University of California – San Francisco, San Francisco, California
| | - Simone Prömel
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Nicole Scholz
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Leipzig University, Leipzig, Germany
| | - Swati Srivastava
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | | | | | - Mario Vallon
- Division of Hematology, Department of Medicine, Stanford University, Stanford, California
| | - Erwin G. Van Meir
- Laboratory of Molecular Neuro-Oncology, Departments of Neurosurgery and Hematology & Medical Oncology, School of Medicine and Winship Cancer Institute, Emory University, Atlanta, Georgia
| | - Benoit Vanhollebeke
- Laboratory of Neurovascular Signaling, Department of Molecular Biology, ULB Neuroscience Institute, Université libre de Bruxelles (ULB), Gosselies, Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO), Wallonia, Belgium
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Kevin M. Wright
- Vollum Institute, Oregon Health & Science University, Portland, Oregon
| | - Kelly R. Monk
- Vollum Institute, Oregon Health & Science University, Portland, Oregon
| | - Amit Mogha
- Vollum Institute, Oregon Health & Science University, Portland, Oregon
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17
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Rahman MA, Manser C, Benlaouer O, Suckling J, Blackburn JK, Silva JP, Ushkaryov YA. C-terminal phosphorylation of latrophilin-1/ADGRL1 affects the interaction between its fragments. Ann N Y Acad Sci 2019; 1456:122-143. [PMID: 31553068 DOI: 10.1111/nyas.14242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/22/2019] [Accepted: 09/05/2019] [Indexed: 12/21/2022]
Abstract
Latrophilin-1 is an adhesion G protein-coupled receptor that mediates the effect of α-latrotoxin, causing massive release of neurotransmitters from nerve terminals and endocrine cells. Autoproteolysis cleaves latrophilin-1 into two parts: the extracellular N-terminal fragment (NTF) and the heptahelical C-terminal fragment (CTF). NTF and CTF can exist as independent proteins in the plasma membrane, but α-latrotoxin binding to NTF induces their association and G protein-mediated signaling. We demonstrate here that CTF in synapses is phosphorylated on multiple sites. Phosphorylated CTF has a high affinity for NTF and copurifies with it on affinity columns and sucrose density gradients. Dephosphorylated CTF has a lower affinity for NTF and can behave as a separate protein. α-Latrotoxin (and possibly other ligands of latrophilin-1) binds both to the NTF-CTF complex and receptor-like protein tyrosine phosphatase σ, bringing them together. This leads to CTF dephosphorylation and facilitates CTF release from the complex. We propose that ligand-dependent phosphorylation-dephosphorylation of latrophilin-1 could affect the interaction between its fragments and functions as a G protein-coupled receptor.
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Affiliation(s)
- M Atiqur Rahman
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Catherine Manser
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ouafa Benlaouer
- School of Pharmacy, University of Kent, Chatham, United Kingdom
| | - Jason Suckling
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - John-Paul Silva
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Yuri A Ushkaryov
- Department of Life Sciences, Imperial College London, London, United Kingdom
- School of Pharmacy, University of Kent, Chatham, United Kingdom
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18
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Sita LV, Diniz GB, Horta-Junior JAC, Casatti CA, Bittencourt JC. Nomenclature and Comparative Morphology of the Teneurin/TCAP/ADGRL Protein Families. Front Neurosci 2019; 13:425. [PMID: 31130838 PMCID: PMC6510184 DOI: 10.3389/fnins.2019.00425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/15/2019] [Indexed: 01/01/2023] Open
Affiliation(s)
- Luciane V. Sita
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Giovanne B. Diniz
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - José A. C. Horta-Junior
- Department of Anatomy, Institute of Biosciences, São Paulo State University, São Paulo, Brazil
| | - Claudio A. Casatti
- Department of Basic Sciences, São Paulo State University, São Paulo, Brazil
| | - Jackson C. Bittencourt
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- Center for Neuroscience and Behavior, Department of Experimental Psychology, Institute of Psychology, University of São Paulo, São Paulo, Brazil
- *Correspondence: Jackson C. Bittencourt,
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19
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Araç D, Li J. Teneurins and latrophilins: two giants meet at the synapse. Curr Opin Struct Biol 2019; 54:141-151. [PMID: 30952063 DOI: 10.1016/j.sbi.2019.01.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022]
Abstract
Teneurins and latrophilins are both conserved families of cell adhesion proteins that mediate cellular communication and play critical roles in embryonic and neural development. However, their mechanisms of action remain poorly understood. In the past several years, three-dimensional structures of teneurins and latrophilins have been reported at atomic resolutions and revealed distinct protein folds and unique structural features. In this review, we discuss these structures which, together with structure-guided biochemical and functional analyses, provide hints for the mechanisms of trans-cellular communication at the synapse and other cell-cell contact sites.
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Affiliation(s)
- Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, IL 60637, USA.
| | - Jingxian Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, IL 60637, USA
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20
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Ushkaryov YA, Lelianova V, Vysokov NV. Catching Latrophilin With Lasso: A Universal Mechanism for Axonal Attraction and Synapse Formation. Front Neurosci 2019; 13:257. [PMID: 30967757 PMCID: PMC6438917 DOI: 10.3389/fnins.2019.00257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 03/05/2019] [Indexed: 11/24/2022] Open
Abstract
Latrophilin-1 (LPHN1) was isolated as the main high-affinity receptor for α-latrotoxin from black widow spider venom, a powerful presynaptic secretagogue. As an adhesion G-protein-coupled receptor, LPHN1 is cleaved into two fragments, which can behave independently on the cell surface, but re-associate upon binding the toxin. This triggers intracellular signaling that involves the Gαq/phospholipase C/inositol 1,4,5-trisphosphate cascade and an increase in cytosolic Ca2+, leading to vesicular exocytosis. Using affinity chromatography on LPHN1, we isolated its endogenous ligand, teneurin-2/Lasso. Both LPHN1 and Ten2/Lasso are expressed early in development and are enriched in neurons. LPHN1 primarily resides in axons, growth cones and presynaptic terminals, while Lasso largely localizes on dendrites. LPHN1 and Ten2/Lasso form a trans-synaptic receptor pair that has both structural and signaling functions. However, Lasso is proteolytically cleaved at multiple sites and its extracellular domain is partially released into the intercellular space, especially during neuronal development, suggesting that soluble Lasso has additional functions. We discovered that the soluble fragment of Lasso can diffuse away and bind to LPHN1 on axonal growth cones, triggering its redistribution on the cell surface and intracellular signaling which leads to local exocytosis. This causes axons to turn in the direction of spatio-temporal Lasso gradients, while LPHN1 knockout blocks this effect. These results suggest that the LPHN1-Ten2/Lasso pair can participate in long- and short-distance axonal guidance and synapse formation.
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Affiliation(s)
- Yuri A Ushkaryov
- Medway School of Pharmacy, University of Kent, Chatham, United Kingdom
| | - Vera Lelianova
- Medway School of Pharmacy, University of Kent, Chatham, United Kingdom
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21
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Schöneberg T, Prömel S. Latrophilins and Teneurins in Invertebrates: No Love for Each Other? Front Neurosci 2019; 13:154. [PMID: 30914910 PMCID: PMC6422961 DOI: 10.3389/fnins.2019.00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 02/11/2019] [Indexed: 01/08/2023] Open
Abstract
Transsynaptic connections enabling cell–cell adhesion and cellular communication are a vital part of synapse formation, maintenance and function. A recently discovered interaction between the Adhesion GPCRs Latrophilins and the type II single transmembrane proteins Teneurins at mammalian synapses is vital for synapse formation and dendrite branching. While the understanding of the effects and the molecular interplay of this Latrophilin-Teneurin partnership is not entirely understood, its significance is highlighted by behavioral and neurological phenotypes in various animal models. As both groups of molecules, Latrophilins and Teneurins, are generally highly conserved, have overlapping expression and often similar functions across phyla, it can be speculated that this interaction, which has been proven essential in mammalian systems, also occurs in invertebrates to control shaping of synapses. Knowledge of the generality of this interaction is especially of interest due to its possible involvement in neuropathologies. Further, several invertebrates serve as model organisms for addressing various neurobiological research questions. So far, an interaction of Latrophilins and Teneurins has not been observed in invertebrates, but our knowledge on both groups of molecules is by far not complete. In this review, we give an overview on existing experimental evidence arguing for as well as against a potential Latrophilin-Teneurin interaction beyond mammals. By combining these insights with evolutionary aspects on each of the interaction partners we provide and discuss a comprehensive picture on the functions of both molecules in invertebrates and the likeliness of an evolutionary conservation of their interaction.
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Affiliation(s)
- Torsten Schöneberg
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - Simone Prömel
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, Leipzig, Germany
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22
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Vezain M, Lecuyer M, Rubio M, Dupé V, Ratié L, David V, Pasquier L, Odent S, Coutant S, Tournier I, Trestard L, Adle-Biassette H, Vivien D, Frébourg T, Gonzalez BJ, Laquerrière A, Saugier-Veber P. A de novo variant in ADGRL2 suggests a novel mechanism underlying the previously undescribed association of extreme microcephaly with severely reduced sulcation and rhombencephalosynapsis. Acta Neuropathol Commun 2018; 6:109. [PMID: 30340542 PMCID: PMC6195752 DOI: 10.1186/s40478-018-0610-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 12/13/2022] Open
Abstract
Extreme microcephaly and rhombencephalosynapsis represent unusual pathological conditions, each of which occurs in isolation or in association with various other cerebral and or extracerebral anomalies. Unlike microcephaly for which several disease-causing genes have been identified with different modes of inheritance, the molecular bases of rhombencephalosynapsis remain unknown and rhombencephalosynapsis presents mainly as a sporadic condition consistent with de novo dominant variations. We report for the first time the association of extreme microcephaly with almost no sulcation and rhombencephalosynapsis in a fœtus for which comparative patient-parent exome sequencing strategy revealed a heterozygous de novo missense variant in the ADGRL2 gene. ADGRL2 encodes latrophilin 2, an adhesion G-protein-coupled receptor whose exogenous ligand is α-latrotoxin. Adgrl2 immunohistochemistry and in situ hybridization revealed expression in the telencephalon, mesencephalon and rhombencephalon of mouse and chicken embryos. In human brain embryos and fœtuses, Adgrl2 immunoreactivity was observed in the hemispheric and cerebellar germinal zones, the cortical plate, basal ganglia, pons and cerebellar cortex. Microfluorimetry experiments evaluating intracellular calcium release in response to α-latrotoxin binding showed significantly reduced cytosolic calcium release in the fœtus amniocytes vs amniocytes from age-matched control fœtuses and in HeLa cells transfected with mutant ADGRL2 cDNA vs wild-type construct. Embryonic lethality was also observed in constitutive Adgrl2−/− mice. In Adgrl2+/− mice, MRI studies revealed microcephaly and vermis hypoplasia. Cell adhesion and wound healing assays demonstrated that the variation increased cell adhesion properties and reduced cell motility. Furthermore, HeLa cells overexpressing mutant ADGRL2 displayed a highly developed cytoplasmic F-actin network related to cytoskeletal dynamic modulation. ADGRL2 is the first gene identified as being responsible for extreme microcephaly with rhombencephalosynapsis. Increased cell adhesion, reduced cell motility and cytoskeletal dynamic alterations induced by the variant therefore represent a new mechanism responsible for microcephaly.
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23
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Anderson GR, Maxeiner S, Sando R, Tsetsenis T, Malenka RC, Südhof TC. Postsynaptic adhesion GPCR latrophilin-2 mediates target recognition in entorhinal-hippocampal synapse assembly. J Cell Biol 2017; 216:3831-3846. [PMID: 28972101 PMCID: PMC5674891 DOI: 10.1083/jcb.201703042] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/24/2017] [Accepted: 08/17/2017] [Indexed: 12/15/2022] Open
Abstract
Synapse assembly likely requires postsynaptic target recognition by incoming presynaptic afferents. Using newly generated conditional knock-in and knockout mice, we show in this study that latrophilin-2 (Lphn2), a cell-adhesion G protein-coupled receptor and presumptive α-latrotoxin receptor, controls the numbers of a specific subset of synapses in CA1-region hippocampal neurons, suggesting that Lphn2 acts as a synaptic target-recognition molecule. In cultured hippocampal neurons, Lphn2 maintained synapse numbers via a postsynaptic instead of a presynaptic mechanism, which was surprising given its presumptive role as an α-latrotoxin receptor. In CA1-region neurons in vivo, Lphn2 was specifically targeted to dendritic spines in the stratum lacunosum-moleculare, which form synapses with presynaptic entorhinal cortex afferents. In this study, postsynaptic deletion of Lphn2 selectively decreased spine numbers and impaired synaptic inputs from entorhinal but not Schaffer-collateral afferents. Behaviorally, loss of Lphn2 from the CA1 region increased spatial memory retention but decreased learning of sequential spatial memory tasks. Thus, Lphn2 appears to control synapse numbers in the entorhinal cortex/CA1 region circuit by acting as a domain-specific postsynaptic target-recognition molecule.
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MESH Headings
- Animals
- Behavior, Animal
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/pathology
- CA1 Region, Hippocampal/physiopathology
- Cells, Cultured
- Dendritic Spines/metabolism
- Dendritic Spines/pathology
- Entorhinal Cortex/metabolism
- Entorhinal Cortex/pathology
- Entorhinal Cortex/physiopathology
- Fear
- Genotype
- Maze Learning
- Memory
- Mice, Mutant Strains
- Motor Activity
- Neurons/metabolism
- Neurons/pathology
- Phenotype
- Presynaptic Terminals/metabolism
- Presynaptic Terminals/pathology
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Rotarod Performance Test
- Smell
- Synaptic Membranes/metabolism
- Synaptic Membranes/pathology
- Synaptic Potentials
- Time Factors
- Transfection
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Affiliation(s)
- Garret R Anderson
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA
- Department of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University Medical School, Stanford, CA
| | - Stephan Maxeiner
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA
| | - Richard Sando
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA
| | - Theodoros Tsetsenis
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA
| | - Robert C Malenka
- Department of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University Medical School, Stanford, CA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University Medical School, Stanford, CA
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24
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Gao S, Liu X, Liu J, Xiong W, Song X, Wu W, Wei L, Li B. Identification and evolution of latrophilin
receptor gene involved in Tribolium castaneum
devolopment and female fecundity. Genesis 2017; 55. [DOI: 10.1002/dvg.23081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Shanshan Gao
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Xing Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Juanjuan Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Wenfeng Xiong
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Xiaowen Song
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Wei Wu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Luting Wei
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
| | - Bin Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences; Nanjing Normal University; Nanjing 210023 China
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25
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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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26
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Langenhan T, Piao X, Monk KR. Adhesion G protein-coupled receptors in nervous system development and disease. Nat Rev Neurosci 2016; 17:550-61. [DOI: 10.1038/nrn.2016.86] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Winkler J, Prömel S. The adhesion GPCR latrophilin - a novel signaling cascade in oriented cell division and anterior-posterior polarity. WORM 2016; 5:e1170274. [PMID: 27383912 DOI: 10.1080/21624054.2016.1170274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 03/15/2016] [Indexed: 01/01/2023]
Abstract
Although several signaling pathways in oriented cell division have been well characterized such as delta/notch inductions or wnt/frizzled-based anterior-posterior polarity, there is strong evidence for additional signal pathways controlling early anterior-posterior polarity decisions. The homolog of the adhesion G protein-coupled receptor latrophilin, LAT-1 has been identified as a receptor essential for oriented cell division in an anterior-posterior direction of specific blastomeres in the early C. elegans embryo. We recently conducted a study aiming at clarifying the signals involved in LAT-1 function. We identified a Gs protein/adenylyl cyclase/cAMP pathway in vitro and demonstrated its physiological relevance in oriented cell division. By interaction with a Gs protein LAT-1 elevates cAMP levels. These data indicate that G-protein signaling in oriented cell division is not solely GPCR-independent. This commentary will discuss our findings in the context of the current knowledge of mechanisms controlling oriented cell division and anterior-posterior polarity. Further, we identify open questions which need to be addressed in the future.
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Affiliation(s)
- Jana Winkler
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University , Leipzig, Germany
| | - Simone Prömel
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University , Leipzig, Germany
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28
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Strutt D, Schnabel R, Fiedler F, Prömel S. Adhesion GPCRs Govern Polarity of Epithelia and Cell Migration. Handb Exp Pharmacol 2016; 234:249-274. [PMID: 27832491 DOI: 10.1007/978-3-319-41523-9_11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In multicellular organisms cells spatially arrange in a highly coordinated manner to form tissues and organs, which is essential for the function of an organism. The component cells and resulting structures are often polarised in one or more axes, and how such polarity is established and maintained correctly has been one of the major biological questions for many decades. Research progress has shown that many adhesion GPCRs (aGPCRs) are involved in several types of polarity. Members of the two evolutionarily oldest groups, Flamingo/Celsr and Latrophilins, are key molecules in planar cell polarity of epithelia or the propagation of cellular polarity in the early embryo, respectively. Other adhesion GPCRs play essential roles in cell migration, indicating that this receptor class includes essential molecules for the control of various levels of cellular organisation.
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Affiliation(s)
- David Strutt
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, UK.
| | - Ralf Schnabel
- Institute of Genetics, TU Braunschweig, Braunschweig, Germany.
| | - Franziska Fiedler
- Medical Faculty, Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - Simone Prömel
- Medical Faculty, Institute of Biochemistry, Leipzig University, Leipzig, Germany.
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29
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Lu YC, Nazarko OV, Sando R, Salzman GS, Li NS, Südhof TC, Araç D. Structural Basis of Latrophilin-FLRT-UNC5 Interaction in Cell Adhesion. Structure 2015; 23:1678-1691. [PMID: 26235030 DOI: 10.1016/j.str.2015.06.024] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 06/18/2015] [Accepted: 06/21/2015] [Indexed: 11/24/2022]
Abstract
Fibronectin leucine-rich repeat transmembrane proteins (FLRTs) are cell-adhesion molecules with emerging functions in cortical development and synapse formation. Their extracellular regions interact with latrophilins (LPHNs) to mediate synapse development, and with Uncoordinated-5 (UNC5)/netrin receptors to control the migration of neurons in the developing cortex. Here, we present the crystal structures of FLRT3 in isolation and in complex with LPHN3. The LPHN3/FLRT3 structure reveals that LPHN3 binds to FLRT3 at a site distinct from UNC5. Structure-based mutations specifically disrupt LPHN3/FLRT3 binding, but do not disturb their interactions with other proteins or their cell-membrane localization. Thus, they can be used as molecular tools to dissect the functions of FLRTs and LPHNs in vivo. Our results suggest that UNC5 and LPHN3 can simultaneously bind to FLRT3, forming a trimeric complex, and that FLRT3 may form transsynaptic complexes with both LPHN3 and UNC5. These findings provide molecular insights for understanding the role of cell-adhesion proteins in synapse function.
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Affiliation(s)
- Yue C Lu
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, GCIS W219, Chicago, IL 60637, USA
| | - Olha V Nazarko
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, GCIS W219, Chicago, IL 60637, USA
| | - Richard Sando
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Gabriel S Salzman
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, GCIS W219, Chicago, IL 60637, USA
| | - Nan-Sheng Li
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, GCIS W219, Chicago, IL 60637, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Demet Araç
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, GCIS W219, Chicago, IL 60637, USA.
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30
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The Adhesion GPCR Latrophilin/CIRL Shapes Mechanosensation. Cell Rep 2015; 11:866-874. [DOI: 10.1016/j.celrep.2015.04.008] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 03/09/2015] [Accepted: 04/01/2015] [Indexed: 01/09/2023] Open
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31
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Jackson VA, del Toro D, Carrasquero M, Roversi P, Harlos K, Klein R, Seiradake E. Structural basis of latrophilin-FLRT interaction. Structure 2015; 23:774-81. [PMID: 25728924 PMCID: PMC4396693 DOI: 10.1016/j.str.2015.01.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/13/2015] [Accepted: 01/19/2015] [Indexed: 11/26/2022]
Abstract
Latrophilins, receptors for spider venom α-latrotoxin, are adhesion type G-protein-coupled receptors with emerging functions in synapse development. The N-terminal region binds the endogenous cell adhesion molecule FLRT, a major regulator of cortical and synapse development. We present crystallographic data for the mouse Latrophilin3 lectin and olfactomedin-like (Olf) domains, thereby revealing the Olf β-propeller fold and conserved calcium-binding site. We locate the FLRT-Latrophilin binding surfaces by a combination of sequence conservation analysis, point mutagenesis, and surface plasmon resonance experiments. In stripe assays, we show that wild-type Latrophilin3 and its high-affinity interactor FLRT2, but not the binding-impaired mutants we generated, promote HeLa cell adhesion. In contrast, cortical neurons expressing endogenous FLRTs are repelled by wild-type Latrophilin3 and not by the binding-impaired mutant. Taken together, we present molecular level insights into Latrophilin structure, its FLRT-binding mechanism, and a role for Latrophilin and FLRT that goes beyond a simply adhesive interaction. The LPHN olfactomedin-like domain forms a five-bladed β propeller A conserved calcium-binding site is located at the center of the protein Latrophilin-FLRT binding depends on a conserved binding site Mutations in the binding site inhibit Latrophilin-FLRT signaling
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Affiliation(s)
- Verity A Jackson
- Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK
| | - Daniel del Toro
- Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Munich-Martinsried, Germany
| | - Maria Carrasquero
- Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK
| | - Pietro Roversi
- Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK
| | - Karl Harlos
- Division of Structural Biology, Oxford University, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Rüdiger Klein
- Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Munich-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany
| | - Elena Seiradake
- Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK.
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32
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Liebscher I, Ackley B, Araç D, Ariestanti DM, Aust G, Bae BI, Bista BR, Bridges JP, Duman JG, Engel FB, Giera S, Goffinet AM, Hall RA, Hamann J, Hartmann N, Lin HH, Liu M, Luo R, Mogha A, Monk KR, Peeters MC, Prömel S, Ressl S, Schiöth HB, Sigoillot SM, Song H, Talbot WS, Tall GG, White JP, Wolfrum U, Xu L, Piao X. New functions and signaling mechanisms for the class of adhesion G protein-coupled receptors. Ann N Y Acad Sci 2014; 1333:43-64. [PMID: 25424900 DOI: 10.1111/nyas.12580] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The class of adhesion G protein-coupled receptors (aGPCRs), with 33 human homologs, is the second largest family of GPCRs. In addition to a seven-transmembrane α-helix-a structural feature of all GPCRs-the class of aGPCRs is characterized by the presence of a large N-terminal extracellular region. In addition, all aGPCRs but one (GPR123) contain a GPCR autoproteolysis-inducing (GAIN) domain that mediates autoproteolytic cleavage at the GPCR autoproteolysis site motif to generate N- and a C-terminal fragments (NTF and CTF, respectively) during protein maturation. Subsequently, the NTF and CTF are associated noncovalently as a heterodimer at the plasma membrane. While the biological function of the GAIN domain-mediated autocleavage is not fully understood, mounting evidence suggests that the NTF and CTF possess distinct biological activities in addition to their function as a receptor unit. We discuss recent advances in understanding the biological functions, signaling mechanisms, and disease associations of the aGPCRs.
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Affiliation(s)
- Ines Liebscher
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
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33
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de Wit J, Ghosh A. Control of neural circuit formation by leucine-rich repeat proteins. Trends Neurosci 2014; 37:539-50. [PMID: 25131359 DOI: 10.1016/j.tins.2014.07.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/02/2014] [Accepted: 07/24/2014] [Indexed: 01/19/2023]
Abstract
The function of neural circuits depends on the precise connectivity between populations of neurons. Increasing evidence indicates that disruptions in excitatory or inhibitory synapse formation or function lead to excitation/inhibition (E/I) imbalances and contribute to neurodevelopmental and psychiatric disorders. Leucine-rich repeat (LRR)-containing surface proteins have emerged as key organizers of excitatory and inhibitory synapses. Distinct LRR proteins are expressed in different cell types and interact with key pre- and postsynaptic proteins. These protein interaction networks allow LRR proteins to coordinate pre- and postsynaptic elements during synapse formation and differentiation, pathway-specific synapse development, and synaptic plasticity. LRR proteins, therefore, play a critical role in organizing synaptic connections into functional neural circuits, and their dysfunction may contribute to neuropsychiatric disorders.
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Affiliation(s)
- Joris de Wit
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; KU Leuven, Center for Human Genetics, 3000 Leuven, Belgium.
| | - Anirvan Ghosh
- Neuroscience Discovery, F. Hoffman-La Roche, 4070 Basel, Switzerland
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34
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Araç D, Aust G, Calebiro D, Engel FB, Formstone C, Goffinet A, Hamann J, Kittel RJ, Liebscher I, Lin HH, Monk KR, Petrenko A, Piao X, Prömel S, Schiöth HB, Schwartz TW, Stacey M, Ushkaryov YA, Wobus M, Wolfrum U, Xu L, Langenhan T. Dissecting signaling and functions of adhesion G protein-coupled receptors. Ann N Y Acad Sci 2012; 1276:1-25. [PMID: 23215895 DOI: 10.1111/j.1749-6632.2012.06820.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
G protein-coupled receptors (GPCRs) comprise an expanded superfamily of receptors in the human genome. Adhesion class G protein-coupled receptors (adhesion-GPCRs) form the second largest class of GPCRs. Despite the abundance, size, molecular structure, and functions in facilitating cell and matrix contacts in a variety of organ systems, adhesion-GPCRs are by far the most poorly understood GPCR class. Adhesion-GPCRs possess a unique molecular structure, with extended N-termini containing various adhesion domains. In addition, many adhesion-GPCRs are autoproteolytically cleaved into an N-terminal fragment (NTF, NT, α-subunit) and C-terminal fragment (CTF, CT, β-subunit) at a conserved GPCR autoproteolysis-inducing (GAIN) domain that contains a GPCR proteolysis site (GPS). These two features distinguish adhesion-GPCRs from other GPCR classes. Though active research on adhesion-GPCRs in diverse areas, such as immunity, neuroscience, and development and tumor biology has been intensified in the recent years, the general biological and pharmacological properties of adhesion-GPCRs are not well known, and they have not yet been used for biomedical purposes. The "6th International Adhesion-GPCR Workshop," held at the Institute of Physiology of the University of Würzburg on September 6-8, 2012, assembled a majority of the investigators currently actively pursuing research on adhesion-GPCRs, including scientists from laboratories in Europe, the United States, and Asia. The meeting featured the nascent mechanistic understanding of the molecular events driving the signal transduction of adhesion-GPCRs, novel models to evaluate their functions, and evidence for their involvement in human disease.
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Affiliation(s)
- Demet Araç
- Stanford University, Stanford, California, USA
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35
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Cloning and activity of a novel α-latrotoxin from red-back spider venom. Biochem Pharmacol 2012; 83:170-83. [DOI: 10.1016/j.bcp.2011.09.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 09/09/2011] [Accepted: 09/28/2011] [Indexed: 11/18/2022]
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36
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Langenhan T, Russ AP. Latrophilin signalling in tissue polarity and morphogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 706:37-48. [PMID: 21618824 DOI: 10.1007/978-1-4419-7913-1_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Understanding the mechanisms that coordinate the polarity of cells and tissues during embryogenesis and morphogenesis is a fundamental problem in developmental biology. We have recently demonstrated that the putative neurotoxin receptor lat-1 defines a mechanism required for the alignment of cell division planes in the early embryo of the nematode C. elegans. Our analysis suggests that lat-1 is required for the propagation rather than the initial establishment of polarity signals. Similar to the role of the flamingo/CELSR protein family in the control of planar cell polarity, these results implicate an evolutionary conserved subfamily of adhesion-GPCRs in the control of tissue polarity and morphogenesis.
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Affiliation(s)
- Tobias Langenhan
- Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
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37
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Martinez AF, Muenke M, Arcos-Burgos M. From the black widow spider to human behavior: Latrophilins, a relatively unknown class of G protein-coupled receptors, are implicated in psychiatric disorders. Am J Med Genet B Neuropsychiatr Genet 2011; 156B:1-10. [PMID: 21184579 PMCID: PMC4101183 DOI: 10.1002/ajmg.b.31137] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 09/28/2010] [Indexed: 12/24/2022]
Abstract
The findings of a recent study associate LPHN3, a member of the latrophilin family, with an increased risk of developing attention deficit/hyperactivity disorder (ADHD), the most common psychiatric disorder in childhood and adolescence. Latrophilins comprise a new family of G protein-coupled receptors of unknown native physiological function that mediate the neurotoxic effects of α-latrotoxin, a potent toxin found in black widow spider venom. This receptor-toxin interaction has helped to elucidate the mechanistic aspects of neurotransmitter and hormone release in vertebrates. Such unprecedented discovery points to a new direction in the assessment of ADHD and suggest that further study of this receptor family may provide novel insights into the etiology and treatment of ADHD and other related psychiatric conditions.
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Affiliation(s)
| | | | - Mauricio Arcos-Burgos
- Correspondence to: Dr. Mauricio Arcos-Burgos, M.D., Ph.D., National Human Genome Research Institute, National Institutes of Health, 35 Convent Drive, MSC 3717, Building 35, Room 1B209, Bethesda, MD 20892.
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38
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Association of the subunits of the calcium-independent receptor of α-latrotoxin. Biochem Biophys Res Commun 2010; 402:658-62. [PMID: 20971062 DOI: 10.1016/j.bbrc.2010.10.078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 10/18/2010] [Indexed: 11/22/2022]
Abstract
CIRL-1 also called latrophilin 1 or CL belongs to the family of adhesion G protein-coupled receptors (GPCRs). As all members of adhesion GPSR family CIRL-1 consists of two heterologous subunits, extracellular hydrophilic p120 and heptahelical membrane protein p85. Both CIRL-1 subunits are encoded by one gene but as a result of intracellular proteolysis of precursor, mature receptor has two-subunit structure. It was also shown that a minor portion of the CIRL-1 receptor complexes dissociates, producing the soluble receptor ectodomain, and this dissociation is due to the second cleavage at the site between the site of primary proteolysis and the first transmembrane domain. Recently model of independent localization p120 and p85 on the cell surface was proposed. In this article we evaluated the amount of p120-p85 complex still presented on the cellular membrane and confirmed that on cell surface major amount of mature CIRL-1 presented as a p120-p85 subunit complex.
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39
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Vassilevski AA, Kozlov SA, Grishin EV. Molecular diversity of spider venom. BIOCHEMISTRY (MOSCOW) 2010; 74:1505-34. [PMID: 20210706 DOI: 10.1134/s0006297909130069] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Spider venom, a factor that has played a decisive role in the evolution of one of the most successful groups of living organisms, is reviewed. Unique molecular diversity of venom components including substances of variable structure (from simple low molecular weight compounds to large multidomain proteins) with different functions is considered. Special attention is given to the structure, properties, and biosynthesis of toxins of polypeptide nature.
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Affiliation(s)
- A A Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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40
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Deyev IE, Petrenko AG. Regulation of CIRL-1 proteolysis and trafficking. Biochimie 2010; 92:418-22. [PMID: 20100540 DOI: 10.1016/j.biochi.2010.01.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
Abstract
Calcium-independent receptor of alpha-latrotoxin (CIRL-1) is an adhesion G protein-coupled receptor implicated in the regulation of exocytosis. CIRL-1 biosynthesis involves constitutive proteolytic processing that takes place in the endoplasmic reticulum, requires the receptor's GPS domain, and yields heterologous two-subunit receptor complexes. It was proposed that the GPS-directed cleavage is based on cis-autoproteolysis. In this study, we demonstrate that activators of protein kinase C - PMA and ionomycin, can inhibit the cleavage of CIRL-1 precursor in transfected cells. Both reagents also downregulate trafficking of CIRL-1 to the cell surface that results in accumulation of the uncleaved receptor precursor inside the cells. Experiments with a non-cleavable soluble mutant of CIRL-1 showed that the downregulation of the receptor trafficking is independent of its cleavage. Our data suggest that the GPS proteolysis of CIRL-1 is not a purely autocatalytic process and may involve auxiliary proteins or factors that become available in the course of CIRL-1 trafficking.
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Affiliation(s)
- Igor E Deyev
- Laboratory of Receptor Cell Biology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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Silva JP, Ushkaryov YA. The latrophilins, "split-personality" receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 706:59-75. [PMID: 21618826 DOI: 10.1007/978-1-4419-7913-1_5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Latrophilin, a neuronal "adhesion-G protein-coupled receptor", is the major brain receptor for alpha-latrotoxin, a black widow spidertoxin which stimulates strong neuronal exocytosis in vertebrates. Latrophilin has an unusual structure consisting of two fragments that are produced by the proteolytic cleavage of the parental molecule and that behave independently in the plasma membrane. On binding an agonist, the fragments reassociate and send an intracellular signal. This signal, transduced by a heterotrimeric G protein, causes release of calcium from intracellular stores and massive release of neurotransmitters. Latrophilin represents a phylogenetically conserved family of receptors, with orthologues found in all animals and up to three homologues present in most chordate species. From mammalian homologues, latrophilins 1 and 3 are expressed in neurons, while latrophilin 2 is ubiquitous. Latrophilin 1 may control synapse maturation and exocytosis, whereas latrophilin 2 may be involved in breast cancer. Latrophilins may play different roles during development and in adult animals: thus, LAT-1 determines cell fate in early embryogenesis in Caenorhabditis elegans and controls neurotransmitter release in adult nematodes. This diversity suggests that the functions of latrophilins may be determined by their interactions with respective ligands. The finding of the ligand of latrophilin 1, the large postsynaptic protein lasso, is the first step in the quest for the physiological functions of latrophilins.
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Abstract
For more than three decades, the venom of the black widow spider and its principal active components, latrotoxins, have been used to induce release of neurotransmitters and hormones and to study the mechanisms of exocytosis. Given the complex nature of alpha--latrotoxin (alpha-LTX) actions, this research has been continuously overshadowed by many enigmas, misconceptions and perpetual changes of the underlying hypotheses. Some of the toxin's mechanisms of action are still not completely understood. Despite all these difficulties, the extensive work of several generations of neurobiologists has brought about a great deal of fascinating insights into pre-synaptic processes and has led to the discovery of several novel proteins and synaptic systems. For example, alpha-LTX studies have contributed to the widespread acceptance of the vesicular theory of transmitter release. Pre-synaptic receptors for alpha-LTX--neurexins, latrophilins and protein tyrosine phosphatase sigma--and their endogenous ligands have now become centrepieces of their own areas of research, with a potential of uncovering new mechanisms of synapse formation and regulation that may have medical implications. However, any future success of alpha-LTX research will require a better understanding of this unusual natural tool and a more precise dissection of its multiple mechanisms.
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Affiliation(s)
- John-Paul Silva
- Division of Cell and Molecular Biology, Imperial College London, Exhibition Road, London, UK
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Krasnoperov V, Deyev IE, Serova OV, Xu C, Lu Y, Buryanovsky L, Gabibov AG, Neubert TA, Petrenko AG. Dissociation of the subunits of the calcium-independent receptor of alpha-latrotoxin as a result of two-step proteolysis. Biochemistry 2009; 48:3230-8. [PMID: 19161337 DOI: 10.1021/bi802163p] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CIRL (the calcium-independent receptor of alpha-latrotoxin), a neuronal cell surface receptor implicated in the regulation of exocytosis, is a member of the GPS family of chimeric cell adhesion/G protein-coupled receptors. The predominant form of CIRL is a membrane-bound complex of two subunits, p120 and p85. Extracellularly oriented p120 contains hydrophilic cell adhesion domains, whereas p85 is a heptahelical membrane protein. Both subunits are encoded by the same gene and represent products of intracellular proteolytic processing of the CIRL precursor. In this study, we demonstrate that a soluble form of CIRL also exists in vitro and in vivo. It results from the further cleavage of CIRL by a second protease. The site of the second cleavage is located in the short N-terminal extracellular tail of p85, between the GPS domain and the first transmembrane segment of CIRL. Thus, the soluble form of CIRL represents a complex of p120 noncovalently bound to a 15 amino acid residue N-terminal peptide fragment of p85. We have previously shown that mutations of CIRL in the GPS domain inhibit intracellular proteolytic processing and also result in the absence of the receptors from the cell surface. Our current data suggest that although CIRL trafficking to the cell membrane is impaired by mutations in the GPS region, it is not blocked completely. However, at the cell surface, the noncleaved mutants are preferentially targeted by the second protease that sheds the extracellular subunit. Therefore, the two-step proteolytic processing may represent a regulatory mechanism that controls cell surface expression of membrane-bound and soluble forms of CIRL.
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Affiliation(s)
- Valery Krasnoperov
- Department of Pharmacology, New York University School of Medicine, New York, New York 10016, USA
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Serova OV, Popova NV, Deev IE, Petrenko AG. [Identification of proteins in complexes with alpha-latrotoxin receptors]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 34:747-53. [PMID: 19088747 DOI: 10.1134/s1068162008060046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A thorough analysis of proteins capable of interacting with presynaptic receptors of alpha-latrotoxin was carried out. The protein components of receptor complexes were isolated from rat brain membranes by affinity chromatography on immobilized alpha-latrotoxin and antibodies to the cytoplasmic moiety of the calcium-independent receptor of alpha-latrotoxin (CIRL) followed by analysis by mass spectrometry. Several proteins were identified, with structural proteins, intracellular signal proteins, and proteins involved in the endocytosis and transport of synaptic vesicles being among them.
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Affiliation(s)
- O V Serova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997 Russia
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Popova NV, Plotnikov AN, Ziganshin RK, Deyev IE, Petrenko AG. Analysis of proteins interacting with TRIP8b adapter. BIOCHEMISTRY (MOSCOW) 2008; 73:644-51. [DOI: 10.1134/s0006297908060035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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46
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Abstract
alpha-Latrotoxin (alpha-LTX) from black widow spider venom induces exhaustive release of neurotransmitters from vertebrate nerve terminals and endocrine cells. This 130-kDa protein has been employed for many years as a molecular tool to study exocytosis. However, its action is complex: in neurons, alpha-LTX induces massive secretion both in the presence of extracellular Ca(2+) (Ca(2+) (e)) and in its absence; in endocrine cells, it usually requires Ca(2+) (e). To use this toxin for further dissection of secretory mechanisms, one needs an in-depth understanding of its functions. One such function that explains some alpha-LTX effects is its ability to form cation-permeable channels in artificial lipid bilayers. The mechanism of alpha-LTX pore formation, revealed by cryo-electron microscopy, involves toxin assembly into homotetrameric complexes which harbor a central channel and can insert into lipid membranes. However, in biological membranes, alpha-LTX cannot exert its actions without binding to specific receptors of the plasma membrane. Three proteins with distinct structures have been found to bind alpha-LTX: neurexin Ialpha, latrophilin 1, and receptor-like protein tyrosine phosphatase sigma. Upon binding a receptor, alpha-LTX forms channels permeable to cations and small molecules; the toxin may also activate the receptor. To distinguish between the pore- and receptor-mediated effects, and to study structure-function relationships in the toxin, alpha-LTX mutants have been used.
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Affiliation(s)
- Yuri A Ushkaryov
- Division of Cell and Molecular Biology, Imperial College London, London, SW7 2AY, UK.
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Rohou A, Nield J, Ushkaryov Y. Insecticidal toxins from black widow spider venom. Toxicon 2006; 49:531-49. [PMID: 17210168 PMCID: PMC2517654 DOI: 10.1016/j.toxicon.2006.11.021] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 11/17/2006] [Indexed: 11/27/2022]
Abstract
The biological effects of Latrodectus spider venom are similar in animals from different phyla, but these symptoms are caused by distinct phylum-specific neurotoxins (collectively called latrotoxins) with molecular masses ranging from 110 to 140 kDa. To date, the venom has been found to contain five insecticidal toxins, termed α, β, γ, δ and ε-latroinsectotoxins (LITs). There is also a vertebrate-specific neurotoxin, α-latrotoxin (α-LTX), and one toxin affecting crustaceans, α-latrocrustatoxin (α-LCT). These toxins stimulate massive release of neurotransmitters from nerve terminals and act (1) by binding to specific receptors, some of which mediate an exocytotic signal, and (2) by inserting themselves into the membrane and forming ion-permeable pores. Specific receptors for LITs have yet to be identified, but all three classes of vertebrate receptors known to bind α-LTX are also present in insects. All LTXs whose structures have been elucidated (α-LIT, δ-LIT, α-LTX and α-LCT) are highly homologous and have a similar domain architecture, which consists of a unique N-terminal sequence and a large domain composed of 13–22 ankyrin repeats. Three-dimensional (3D) structure analysis, so far done for α-LTX only, has revealed its dimeric nature and an ability to form symmetrical tetramers, a feature probably common to all LTXs. Only tetramers have been observed to insert into membranes and form pores. A preliminary 3D reconstruction of a δ-LIT monomer demonstrates the spatial similarity of this toxin to the monomer of α-LTX.
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Affiliation(s)
| | | | - Y.A. Ushkaryov
- Corresponding author. Tel.: +44 20 7594 5237; fax: +44 20 7594 5207.
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α-LTX and α-LTXN4C induce [Ca2+]i elevation through different mechanisms in pancreatic β cells. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/s11434-005-1029-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Andreev IA, Danilevich VN, Grishin EV. [Alternative splicing of pre-mRNA encoding the Musca domestica latrophilin-like protein(LLP): primary structures of four spliced forms of mRNA and their protein products]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2005; 31:175-85. [PMID: 15889792 DOI: 10.1007/s11171-005-0022-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An internal DNA fragment (approximately 2000 bp) homologous to the conserved regions of genes encoding latrophilin-like proteins (LLPs) was obtained by the PCR technique using degenerate primers to these gene regions. The gene-specific primers were synthesized based on the results of sequencing of the isolated fragment, and all overlapping cDNA fragments of the llp gene encoding the Musca domestica LLP were obtained by the rapid amplification of cDNA 5'- and 3'-ends (5'- and 3'-RACE). Four alternatively spliced mRNAs were found while sequencing the obtained cDNA fragments. Two long mRNAs (approximately 6000 nt) differ in the structures of both the sites encoding signal peptides and 5'-terminal untranslated regions. They encode large proteins (approximately 1800 aa), whose domain organization is similar to that of mammalian latrophilins. Each deduced protein contains a domain with seven transmembrane regions followed by an extended cytoplasmic C-terminal domain. Two other mRNA forms are derived from these long mRNAs; they encode proteins severly truncated at their C-termini (approximately 900 aa). They are composed of only three transmembrane regions and a short unique cytoplasmic C-terminal domain (23 aa). The limitations and drawbacks of the existing 3'-RACE techniques found during study of the long alternatively spliced cDNAs are analyzed, and ways for overcoming these difficulties are proposed.
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Liu J, Wan Q, Lin X, Zhu H, Volynski K, Ushkaryov Y, Xu T. α-Latrotoxin Modulates the Secretory Machinery via Receptor-Mediated Activation of Protein Kinase C. Traffic 2005; 6:756-65. [PMID: 16101679 DOI: 10.1111/j.1600-0854.2005.00313.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hypothesis whether alpha-latrotoxin (LTX) could directly regulate the secretory machinery was tested in pancreatic beta cells using combined techniques of membrane capacitance (Cm) measurement and Ca2+ uncaging. Employing ramp increase in [Ca2+]i to stimulate exocytosis, we found that LTX lowers the Ca2+ threshold required for exocytosis without affecting the size of the readily releasable pool (RRP). The burst component of exocytosis in response to step-like [Ca2+]i increase generated by flash photolysis of caged Ca2+ was also speeded up by LTX treatment. LTX increased the maximum rate of exocytosis compared with control responses with similar postflash [Ca2+]i and shifted the Ca2+ dependence of the exocytotic machinery toward lower Ca2+ concentrations. LTXN4C, a LTX mutant which cannot form membrane pores or penetrate through the plasma membrane but has similar affinity for the receptors as the wild-type LTX, mimicked the effect of LTX. Moreover, the effects of both LTX and LTXN4C) were independent of intracellular or extracellular Ca2+ but required extracellular Mg2+. Our data propose that LTX, by binding to the membrane receptors, sensitizes the fusion machinery to Ca2+ and, hence, may permit release at low [Ca2+]i level. This sensitization is mediated by activation of protein kinase C.
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Affiliation(s)
- Jie Liu
- Institute of Biophysics and Biochemistry, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074. P. R. China
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