Figure 1.

Diagram depicting the localization and interactions of NL1, NL2, and Cb at excitatory and inhibitory synapses. The extracellular domains of NL1 and NL2 bind presynaptic neurexins, which are bound to the presynaptic scaffold proteins Munc18 interacting protein (MINT) and calcium/calmodulin-dependent serine protein kinase (CASK). NL1 is located at excitatory synapses and binds the postsynaptic density protein 95 (PSD-95) intracellularly, which also binds NMDA receptors. NL1 also directly or indirectly binds the Shank family scaffolding proteins. NL2 is located at inhibitory synapses and binds to synaptic scaffolding molecule (S-SCAM) as well as collybistin, which recruits the scaffolding protein gephyrin from intracellular stores (not shown) to the postsynapse. Gephyrin mediates the accumulation of GABA_A receptors to the membrane (for reviews, see [32, 84]).