西亚试剂：Structural basis for synaptic adhesion mediated by neurolig

Abstract

The heterophilic synaptic adhesion molecules neuroligins and neurexins are essential for establishing and maintaining neuronal circuits by modulating the formation and maturation of synapses. The neuroligin-neurexin adhesion is Ca2+-dependent and regulated by alternative splicing. We report a structure of the complex at a resolution of 2.4 Å between the mouse neuroligin-1 (NL1) cholinesterase-like domain and the mouse neurexin-1 (NX1) LNS (laminin, neurexin and sex hormone–binding globulin–like) domain. The structure revealed a delicate neuroligin-neurexin assembly mediated by a hydrophilic, Ca2+-mediated and solvent-supplemented interface, rendering it capable of being modulated by alternative splicing and other regulatory factors. Thermodynamic data supported a mechanism wherein splicing site B of NL1 acts by modulating a salt bridge at the edge of the NL1-NX1 interface. Mapping neuroligin mutations implicated in autism indicated that most such mutations are structurally destabilizing, supporting deficient neuroligin biosynthesis and processing as a common cause for this brain disorder.