Neuroligin 2 is exclusively localized to inhibitory synapses.
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.
Varoqueaux
Frédérique
F
Max-Planck-Institute for Experimental Medicine, Department of Molecular Neurobiology, Göttingen, Germany.
Jamain
Stéphane
S
Brose
Nils
N
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
D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C098003:neuroligin 2