1
|
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.
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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
| | | |
Collapse
|
4
|
Vysokov NV, Silva JP, Lelianova VG, Suckling J, Cassidy J, Blackburn JK, Yankova N, Djamgoz MB, Kozlov SV, Tonevitsky AG, Ushkaryov YA. Proteolytically released Lasso/teneurin-2 induces axonal attraction by interacting with latrophilin-1 on axonal growth cones. eLife 2018; 7:37935. [PMID: 30457553 PMCID: PMC6245728 DOI: 10.7554/elife.37935] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 10/19/2018] [Indexed: 11/15/2022] Open
Abstract
A presynaptic adhesion G-protein-coupled receptor, latrophilin-1, and a postsynaptic transmembrane protein, Lasso/teneurin-2, are implicated in trans-synaptic interaction that contributes to synapse formation. Surprisingly, during neuronal development, a substantial proportion of Lasso is released into the intercellular space by regulated proteolysis, potentially precluding its function in synaptogenesis. We found that released Lasso binds to cell-surface latrophilin-1 on axonal growth cones. Using microfluidic devices to create stable gradients of soluble Lasso, we show that it induces axonal attraction, without increasing neurite outgrowth. Using latrophilin-1 knockout in mice, we demonstrate that latrophilin-1 is required for this effect. After binding latrophilin-1, Lasso causes downstream signaling, which leads to an increase in cytosolic calcium and enhanced exocytosis, processes that are known to mediate growth cone steering. These findings reveal a novel mechanism of axonal pathfinding, whereby latrophilin-1 and Lasso mediate both short-range interaction that supports synaptogenesis, and long-range signaling that induces axonal attraction. The brain is a complex mesh of interconnected neurons, with each cell making tens, hundreds, or even thousands of connections. These links can stretch over long distances, and establishing them correctly during development is essential. Developing neurons send out long and thin structures, called axons, to reach distant cells. To guide these growing axons, neurons release molecules that work as traffic signals: some attract axons whilst others repel them, helping the burgeoning structures to twist and turn along their travel paths. When an axon reaches its target cell, the two cells join to each other by forming a structure called a synapse. To make the connection, surface proteins on the axon latch onto matching proteins on the target cell, zipping up the synapse. There are many different types of synapses in the brain, but we only know a few of the surface molecules involved in their creation – not enough to explain synaptic variety. Two of these surface proteins are latrophilin-1, which is produced by the growing axon, and Lasso, which sits on the membrane of the target cell. The two proteins interact strongly, anchoring the axon to the target cell and allowing the synapse to form. However, a previous recent discovery by Vysokov et al. has revealed that an enzyme can also cut Lasso from the membrane of the target cell. The ‘free’ protein can still interact with latrophilin-1, but as it is shed by the target cell, it can no longer serve as an anchor for the synapse. Could it be that free Lasso acts as a traffic signal instead? Here, Vysokov et al. tried to answer this by growing neurons from a part of the brain called the hippocampus in a special labyrinth dish. When free Lasso was gradually introduced in the culture through microscopic channels, it interacted with latrophilin-1 on the surface of the axons. This triggered internal changes that led the axons to add more membrane where they had sensed Lasso, making them grow towards the source of the signal. The results demonstrate that a target cell can both carry and release Lasso, using this duplicitous protein to help attract growing axons as well as anchor them. The work by Vysokov et al. contributes to our knowledge of how neurons normally connect, which could shed light on how this process can go wrong. This may be relevant to understand conditions such as schizophrenia and ADHD, where patients’ brains often show incorrect wiring.
Collapse
Affiliation(s)
- Nickolai V Vysokov
- School of Pharmacy, University of Kent, Chatham, United Kingdom.,Department of Life Sciences, Imperial College London, London, United Kingdom.,Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom.,BrainPatch Ltd, London, United Kingdom
| | - John-Paul Silva
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Bioanalytical Sciences, Non-clinical development, UCB-Pharma, Berkshire, United Kingdom
| | - Vera G Lelianova
- School of Pharmacy, University of Kent, Chatham, United Kingdom.,Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Jason Suckling
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Thomsons Online Benefits, London, United Kingdom
| | - John Cassidy
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Arix Bioscience, London, United Kingdom
| | - Jennifer K Blackburn
- School of Pharmacy, University of Kent, Chatham, United Kingdom.,Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, United States
| | - Natalia Yankova
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, King's College London, London, United Kingdom
| | - Mustafa Ba Djamgoz
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Serguei V Kozlov
- Center for Advanced Preclinical Research, National Cancer Institute, Frederick, United States
| | - Alexander G Tonevitsky
- Higher School of Economics, Moscow, Russia.,Scientific Research Centre Bioclinicum, Moscow, Russia
| | - Yuri A Ushkaryov
- School of Pharmacy, University of Kent, Chatham, United Kingdom.,Department of Life Sciences, Imperial College London, London, United Kingdom
| |
Collapse
|
5
|
Gao S, Xiong W, Wei L, Liu J, Liu X, Xie J, Song X, Bi J, Li B. Transcriptome profiling analysis reveals the role of latrophilin in controlling development, reproduction and insecticide susceptibility in Tribolium castaneum. Genetica 2018; 146:287-302. [DOI: 10.1007/s10709-018-0020-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/30/2018] [Indexed: 12/23/2022]
|
6
|
Faiz A, Donovan C, Nieuwenhuis MA, van den Berge M, Postma DS, Yao S, Park CY, Hirsch R, Fredberg JJ, Tjin G, Halayko AJ, Rempel KL, Ward JPT, Lee T, Bossé Y, Nickle DC, Obeidat M, Vonk JM, Black JL, Oliver BG, Krishnan R, McParland B, Bourke JE, Burgess JK. Latrophilin receptors: novel bronchodilator targets in asthma. Thorax 2016; 72:74-82. [PMID: 27325752 PMCID: PMC5329048 DOI: 10.1136/thoraxjnl-2015-207236] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 01/30/2023]
Abstract
Background Asthma affects 300 million people worldwide. In asthma, the major cause of morbidity and mortality is acute airway narrowing, due to airway smooth muscle (ASM) hypercontraction, associated with airway remodelling. However, little is known about the transcriptional differences between healthy and asthmatic ASM cells. Objectives To investigate the transcriptional differences between asthmatic and healthy airway smooth muscle cells (ASMC) in culture and investigate the identified targets using in vitro and ex vivo techniques. Methods Human asthmatic and healthy ASMC grown in culture were run on Affymetrix_Hugene_1.0_ST microarrays. Identified candidates were confirmed by PCR, and immunohistochemistry. Functional analysis was conducted using in vitro ASMC proliferation, attachment and contraction assays and ex vivo contraction of mouse airways. Results We suggest a novel role for latrophilin (LPHN) receptors, finding increased expression on ASMC from asthmatics, compared with non-asthmatics in vivo and in vitro, suggesting a role in mediating airway function. A single nucleotide polymorphism in LPHN1 was associated with asthma and with increased LPHN1 expression in lung tissue. When activated, LPHNs regulated ASMC adhesion and proliferation in vitro, and promoted contraction of mouse airways and ASMC. Conclusions Given the need for novel inhibitors of airway remodelling and bronchodilators in asthma, the LPHN family may represent promising novel targets for future dual therapeutic intervention.
Collapse
Affiliation(s)
- A Faiz
- Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia.,University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, The Netherlands
| | - C Donovan
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Pharmacology and Therapeutics, Lung Health Research Centre, University of Melbourne, Melbourne, Victoria, Australia
| | - M Ae Nieuwenhuis
- University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, The Netherlands
| | - M van den Berge
- University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, The Netherlands
| | - D S Postma
- University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, The Netherlands
| | - S Yao
- Center for Vascular Biology Research, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - C Y Park
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - R Hirsch
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - J J Fredberg
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - G Tjin
- Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia
| | - A J Halayko
- Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - K L Rempel
- Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - T Lee
- Kings College London, London, UK
| | - Y Bossé
- Department of Molecular Medicine, Institut universitaire de cardiologie et de pneumologie de Québec, Laval University, Québec, Quebec, Canada
| | - D C Nickle
- Merck Research Laboratories, Genetics and Pharmacogenomics, Boston, Massachusetts, USA
| | - M Obeidat
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada
| | - Judith M Vonk
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, The Netherlands
| | - J L Black
- Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine, The University of Sydney, Sydney, New South Wales, Australia
| | - B G Oliver
- Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia.,School of Medical and Molecular Biosciences, University of Technology, Sydney, New South Wales, Australia
| | - R Krishnan
- Center for Vascular Biology Research, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - B McParland
- Discipline of Pharmacology, Faculty of Medicine, The University of Sydney, Sydney, New South Wales, Australia
| | - J E Bourke
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.,Department of Pharmacology and Therapeutics, Lung Health Research Centre, University of Melbourne, Melbourne, Victoria, Australia
| | - J K Burgess
- Woolcock Institute of Medical Research, The University of Sydney, Glebe, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine, The University of Sydney, Sydney, New South Wales, Australia.,University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands
| |
Collapse
|
7
|
Woelfle R, D'Aquila AL, Pavlović T, Husić M, Lovejoy DA. Ancient interaction between the teneurin C-terminal associated peptides (TCAP) and latrophilin ligand-receptor coupling: a role in behavior. Front Neurosci 2015; 9:146. [PMID: 25964737 PMCID: PMC4408839 DOI: 10.3389/fnins.2015.00146] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 04/08/2015] [Indexed: 12/28/2022] Open
Abstract
Teneurins are multifunctional transmembrane proteins that are found in all multicellular animals and exist as four paralogous forms in vertebrates. They are highly expressed in the central nervous system, where they exert their effects, in part, by high-affinity binding to latrophilin (LPHN), a G-protein coupled receptor (GPCR) related to the adhesion and secretin GPCR families. The teneurin C-terminal associated peptides (TCAPs) are encoded by the terminal exon of all four teneurins, where TCAPs 1 and 3 are independently transcribed as soluble peptides, and TCAPs 2 and 4 remain tethered to their teneurin proprotein. Synthetic TCAP-1 interacts with LPHN, with an association with β-dystroglycan, to induce a tissue-dependent signal cascade to modulate cytoskeletal dynamics. TCAP-1 reduces stress-induced behaviors associated with anxiety, addiction and depression in a variety of models, in part, by regulating synaptic plasticity. Therefore, the TCAP-1-teneurin-LPHN interaction represents a novel receptor-ligand model and may represent a key mechanism underlying the association of behavior and neurological conditions.
Collapse
Affiliation(s)
- Rebecca Woelfle
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Andrea L D'Aquila
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Téa Pavlović
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Mia Husić
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada ; Protagenic Therapeutics Inc. New York, NY, USA
| |
Collapse
|
8
|
Curran S, Ahn JW, Grayton H, Collier DA, Ogilvie CM. NRXN1 deletions identified by array comparative genome hybridisation in a clinical case series - further understanding of the relevance of NRXN1 to neurodevelopmental disorders. J Mol Psychiatry 2013; 1:4. [PMID: 25408897 PMCID: PMC4223877 DOI: 10.1186/2049-9256-1-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 11/29/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Microdeletions in the NRXN1 gene have been associated with a range of neurodevelopmental disorders, including autism spectrum disorders, schizophrenia, intellectual disability, speech and language delay, epilepsy and hypotonia. RESULTS In the present study we performed array CGH analysis on 10,397 individuals referred for diagnostic cytogenetic analysis, using a custom oligonucleotide array, which included 215 NRXN1 probes (median spacing 4.9 kb). We found 34 NRXN1 deletions (0.33% of referrals) ranging from 9 to 942 kb in size, of which 18 were exonic (0.17%). Three deletions affected exons also in the beta isoform of NRXN1. No duplications were found. Patients had a range of phenotypes including developmental delay, learning difficulties, attention deficit hyperactivity disorder (ADHD), autism, speech delay, social communication difficulties, epilepsy, behaviour problems and microcephaly. Five patients who had deletions in NRXN1 had a second CNV implicated in neurodevelopmental disorder: a CNTNAP2 and CSMD3 deletion in patients with exonic NRXN1 deletions, and a Williams-Beuren syndrome deletion and two 22q11.2 duplications in patients with intronic NRXN1 deletions. CONCLUSIONS Exonic deletions in the NRXN1 gene, predominantly affecting the alpha isoform, were found in patients with a range of neurodevelopmental disorders referred for diagnostic cytogenetic analysis. The targeting of dense oligonucleotide probes to the NRXN1 locus on array comparative hybridisation platforms provides detailed characterisation of deletions in this gene, and is likely to add to understanding of the importance of NRXN1 in neural development.
Collapse
Affiliation(s)
- Sarah Curran
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Kings College London, De Crespigny Park, Denmark Hill, London, SE5 8AF UK
| | - Joo Wook Ahn
- Cytogenetics Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Hannah Grayton
- MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London, SE5 8AF UK
| | - David A Collier
- MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London, SE5 8AF UK
| | | |
Collapse
|
9
|
Davletov B, Ferrari E, Ushkaryov Y. Presynaptic neurotoxins: an expanding array of natural and modified molecules. Cell Calcium 2012; 52:234-40. [PMID: 22658826 DOI: 10.1016/j.ceca.2012.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 05/04/2012] [Accepted: 05/13/2012] [Indexed: 11/15/2022]
Abstract
The process of neurotransmitter release from nerve terminals is a target for a wide array of presynaptic toxins produced by various species, from humble bacteria to arthropods to vertebrate animals. Unlike other toxins, most presynaptic neurotoxins do not kill cells but simply inhibit or activate synaptic transmission. In this review, we describe two types of presynaptic neurotoxins: clostridial toxins and latrotoxins, which are, respectively, the most potent blockers and stimulators of neurotransmitter release. These toxins have been instrumental in defining presynaptic functions and are now widely used in research and medicine. Here, we would like to analyse the diversity of these toxins and demonstrate how the knowledge of their structures and mechanisms of action can help us to design better tools for research and medical applications. We will look at natural and synthetic variations of these exquisite molecular machines, highlighting recent advances in our understanding of presynaptic toxins and questions that remain to be answered. If we can decipher how a given biomolecule is modified by nature to target different species, we will be able to design new variants that carry only desired characteristics to achieve specific therapeutic, agricultural or research goals. Indeed, a number of research groups have already initiated a quest to harness the power of natural toxins with the aim of making them more specifically targeted and safer for future research and medical applications.
Collapse
Affiliation(s)
- Bazbek Davletov
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.
| | | | | |
Collapse
|
10
|
Latrophilin 1 and its endogenous ligand Lasso/teneurin-2 form a high-affinity transsynaptic receptor pair with signaling capabilities. Proc Natl Acad Sci U S A 2011; 108:12113-8. [PMID: 21724987 DOI: 10.1073/pnas.1019434108] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Latrophilin 1 (LPH1), a neuronal receptor of α-latrotoxin, is implicated in neurotransmitter release and control of presynaptic Ca(2+). As an "adhesion G-protein-coupled receptor," LPH1 can convert cell surface interactions into intracellular signaling. To examine the physiological functions of LPH1, we used LPH1's extracellular domain to purify its endogenous ligand. A single protein of ∼275 kDa was isolated from rat brain and termed Lasso. Peptide sequencing and molecular cloning have shown that Lasso is a splice variant of teneurin-2, a brain-specific orphan cell surface receptor with a function in neuronal pathfinding and synaptogenesis. We show that LPH1 and Lasso interact strongly and specifically. They are always copurified from rat brain extracts. Coculturing cells expressing LPH1 with cells expressing Lasso leads to their mutual attraction and formation of multiple junctions to which both proteins are recruited. Cells expressing LPH1 form chimerical synapses with hippocampal neurons in cocultures; LPH1 and postsynaptic neuronal protein PSD-95 accumulate on opposite sides of these structures. Immunoblotting and immunoelectron microscopy of purified synapses and immunostaining of cultured hippocampal neurons show that LPH1 and Lasso are enriched in synapses; in both systems, LPH1 is presynaptic, whereas Lasso is postsynaptic. A C-terminal fragment of Lasso interacts with LPH1 and induces Ca(2+) signals in presynaptic boutons of hippocampal neurons and in neuroblastoma cells expressing LPH1. Thus, LPH1 and Lasso can form transsynaptic complexes capable of inducing presynaptic Ca(2+) signals, which might affect synaptic functions.
Collapse
|
11
|
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.
Collapse
|