Figure 1.

Schematic description of the inhibitory signal transmission and postsynaptic architecture. The synapse is stabilized by interactions between the cell-adhesion molecules, neurexin and neuroligin, present at the pre- and postsynaptic site, respectively. GABA and glycine released from the presynaptic neuron bind to their cognate receptors embedded in the postsynaptic membrane. The GABA_A and glycine receptors are stabilized by the scaffolding protein gephyrin, which forms an extended structure underneath the postsynaptic membrane. Collybistin (CB) operates as an adaptor protein for gephyrin and recruits gephyrin to postsynaptic sites. CB (shown here in its conformational active or open state) interacts with various other neuronal factors including the cytosolic region of neuroligin 2 and the GABA_A receptor. CB localization at the postsynaptic membranous site is largely mediated by its interaction with various phosphoinositides including phosphatidylinositol-3-phosphate (PI3P).