GRIA2 and major depressive disorder: Furthermore, the interaction of GluA2 with the synaptic protein BRAG2, a guanine-nucleotide exchange factor (GEF) for the coat-recruitment GTPase Arf6, occurs in a GluA2 tyrosine phosphorylation-dependent manner, which induces the AMPA receptor endocytosis in long-term synaptic depression (Scholz et al., 2010).