Vanderbilt Summer Science Academy

Internalization Dynamics of the Disease-Associated Dopamine Transporter A559V Variant

Dopamine is a neurotransmitter responsible for behaviors such as attention and reward. The dopamine transporter protein (DAT) regulates the amount of dopamine in a neuronal synapse by reuptake, which facilitates effective communication between neurons. Recently, the dopamine transporter protein A559V variant was discovered in patients diagnosed with disorders such as autism spectrum disorder (ASD), attention-deficit/hyperactive disorder (ADHD), and bipolar disorder. In this effort, we aim to investigate the internalization dynamics of the A559V variant protein. In order to study internalization, HEK293 cells are transiently transfected with two coding variant plasmids- one for the A559V variant and one for the wild type. When the cells express their respective dopamine transporter, the DAT proteins are tagged with DAT specific ligand-conjugated quantum dots. 3D single quantum-dot tracking experiments will be carried out by spinning disk confocal microscopy, which allows us to track the movement of the individual transporter proteins in living cells. We hypothesize that the internalization dynamics of the A559V variant protein will distinctly differ from those of the wild-type, which may indicate a correlation between internalization and dysfunction. This information could subsequently be implemented in quantitative diagnosis for behavior disorders.