Syntaxin 1 Ser¹⁴ phosphorylation is required for nonvesicular dopamine release

Area of Science:

• Neuroscience
• Molecular Biology
• Pharmacology

Background:

• Amphetamine (AMPH) is a widely abused psychostimulant.
• AMPH increases dopamine (DA) neurotransmission, contributing to its stimulant effects.
• Nonvesicular DA release, mediated by dopamine transporter (DAT) reversal, is a key mechanism.

Purpose of the Study:

• To investigate the role of Syntaxin 1 (Stx1) phosphorylation in AMPH-induced nonvesicular DA release.
• To determine the functional significance of Stx1 phosphorylation in AMPH-related behaviors.

Main Methods:

• Molecular dynamics simulations of the DAT/Stx1 complex.
• Studies in *Drosophila melanogaster* to assess AMPH-induced preference and sexual motivation.

Main Results:

• Stx1 phosphorylation at Ser14 is critical for AMPH-induced nonvesicular DA release.
• Phosphorylation of DAT and Stx1 promotes a DA-releasing state by destabilizing salt bridges in the DAT intracellular gate.
• Stx1 phosphorylation regulates AMPH-induced behavioral responses in *Drosophila*.

Conclusions:

• Phosphorylation of Syntaxin 1 is a crucial regulator of amphetamine-induced nonvesicular dopamine release.
• This mechanism, involving DAT conformational changes, provides new insights into psychostimulant action and abuse.
• Findings highlight Stx1 as a potential target for understanding and treating amphetamine addiction.