A network of phosphatidylinositol binding sites on the dopamine transporter regulates amphetamine behavior in Drosophila Melanogaster

Reward modulates the saliency of a specific drug exposure and is essential for the transition to addiction. Numerous human PET-fMRI studies establish a link between midbrain dopamine (DA) release, DA transporter (DAT) availability, and reward responses. However, how and whether DAT function and regu...

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Bibliographic Details
Published in:Molecular psychiatry 2021-08, Vol.26 (8), p.4417
Main Authors: Belovich, Andrea N, Aguilar, Jenny I, Mabry, Samuel J, Cheng, Mary H, Zanella, Daniele, Hamilton, Peter J, Stanislowski, Daniel J
Format: Article
Language:English
Subjects:
Amphetamine abuse
Amphetamines
Development and progression
Dopaminergic mechanisms
Health aspects
Phospholipids
Physiological aspects
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Summary:Reward modulates the saliency of a specific drug exposure and is essential for the transition to addiction. Numerous human PET-fMRI studies establish a link between midbrain dopamine (DA) release, DA transporter (DAT) availability, and reward responses. However, how and whether DAT function and regulation directly participate in reward processes remains elusive. Here, we developed a novel experimental paradigm in Drosophila melanogaster to study the mechanisms underlying the psychomotor and rewarding properties of amphetamine (AMPH). AMPH principally mediates its pharmacological and behavioral effects by increasing DA availability through the reversal of DAT function (DA efflux). We have previously shown that the phospholipid, phosphatidylinositol (4, 5)-bisphosphate (PIP.sub.2), directly interacts with the DAT N-terminus to support DA efflux in response to AMPH. In this study, we demonstrate that the interaction of PIP.sub.2 with the DAT N-terminus is critical for AMPH-induced DAT phosphorylation, a process required for DA efflux. We showed that PIP.sub.2 also interacts with intracellular loop 4 at R443. Further, we identified that R443 electrostatically regulates DA efflux as part of a coordinated interaction with the phosphorylated N-terminus. In Drosophila, we determined that a neutralizing substitution at R443 inhibited the psychomotor actions of AMPH. We associated this inhibition with a decrease in AMPH-induced DA efflux in isolated fly brains. Notably, we showed that the electrostatic interactions of R443 specifically regulate the rewarding properties of AMPH without affecting AMPH aversion. We present the first evidence linking PIP.sub.2, DAT, DA efflux, and phosphorylation processes with AMPH reward.
ISSN:1359-4184
DOI:10.1038/s41380-019-0620-0