title: Neuroligin 2 is exclusively localized to inhibitory synapses.
abstract: Neuroligins are cell adhesion proteins that are thought to instruct the formation and alignment of synaptic specializations. The three known rodent neuroligin isoforms share homologous extracellular acetylcholinesterase-like domains that bridge the synaptic cleft and bind beta-neurexins. All neuroligins have identical intracellular C-terminal motifs that bind to PDZ domains of various target proteins. Neuroligin 1 is specifically localized to glutamatergic postsynaptic specializations. We show here that neuroligin 2 is exclusively localized to inhibitory synapses in rat brain and dissociated neurons. In immature neurons, neuroligin 2 is found at synapses and also at GABAA receptor aggregates that are not facing presynaptic termini, indicating that postsynaptic mechanisms lead to synaptic recruitment of neuroligin 2. Our findings identify neuroligin 2 as a new cell adhesion protein specific for inhibitory synapses and open new avenues for identifiying the constituents of this unique type of postsynaptic specialization.
authors.affiliation: Max-Planck-Institute for Experimental Medicine, Department of Molecular Neurobiology, Göttingen, Germany.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Varoqueaux
authors.forename: Stéphane
authors.initials: S
authors.lastname: Jamain
authors.forename: Nils
authors.initials: N
authors.lastname: Brose
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D019556:COS Cells; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000235:genetics / Q000502:physiology; D015816:Cell Adhesion Molecules, Neuronal; D002460:Cell Line; D002522:Chlorocebus aethiops; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics* / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013569:Synapses / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C098003:neuroligin 2