Gephyrin, a major postsynaptic protein of GABAergic synapses

gamma-aminobutyric acid type A (GABA(A)) receptors are located at the majority of inhibitory synapses in the mammalian brain. However, the mechanisms by which GABA(A) receptor subunits are targeted to, and clustered in, the postsynaptic membrane are poorly understood. Recent studies have demonstrated that gephyrin, a protein first identified as a component of the glycine receptor (GlyR) complex, is colocalized with several subtypes of GABA(A) receptors and is involved in the stabilization of postsynaptic GABA(A) receptor clusters. Thus, gephyrin functions as a clustering protein for major subtypes of inhibitory ion channel receptors.