Figure 8.

Model of constitutive and regulated trafficking of EAAT2a and EAAT2b. EAAT2a undergoes constitutive cycling to and from the cell surface. The cell-surface expression of EAAT2b, however, can by modulated in a regulated fashion. EAAT2b is generally found at the cell surface where its localization is stabilized by its interaction with DLG1. An AMPA receptor-mediated increase in intracellular calcium can lead to activation of CaMKII, which phosphorylates DLG1. Phosphorylated DLG1 dissociates from its PDZ-binding partner, EAAT2b, which destabilizes its cell surface localization.