Regulation of the dopamine transporter by dopamine D2 receptors and the AKT‐GSK3 signaling cascade

Abstract

Dopamine (DA) D2 receptors (D2R) modulate DA neurotransmission via actions on DA neurons and their targets. The DA transporter (DAT, SL6A3), is regulated by and forms a complex with D2 short autoreceptors. D2R signaling has been shown to involve the protein kinase B (Akt)‐glycogen synthase kinase‐3 (GSK3) cascade. As the interplay between D2R and Akt signaling to DAT is poorly understood, we sought to establish an in vitro model for their functional interactions using real‐time assessment of DAT activity with a novel non‐DA substrate of DAT that provides for measurements of DAT without activation of the D2R. In parallel, [3H]DA uptake studies are pursued, along with western blot analyses. Results indicate that Akt inhibition decreases basal DA uptake whereas GSK3 inhibition lead to increased basal DA uptake in HEK‐293T cells transiently transfected with hDAT and FLAG‐tagged D2R. This work has been supported by NIH grant #T32 NS061201.