Regulation of the dopamine transporter by microtubule proteins

Mental Health and Addictions

Neurotransmission is mediated by the release of neurotransmitters into the synaptic cleft, which allows for the activation of presynaptic or postsynaptic receptors.  The availability of neurotransmitters in the synapse is largely regulated by neurotransmitter transporters, which implicates the importance of transporters in neurotransmission.  While post-translational modifications, such as phosphorylation, glycosylation and ubiquitination, have been shown to regulate transporter activity, there is growing evidence that protein-protein interactions can facilitate transporter regulation.  

My lab is involved in studying protein-protein interactions that affect dopamine neurobiology and have identified protein-protein interactions between the dopamine transporter (DAT), a-synuclein and the dopamine D2 receptor (Fig.1).  These interactions have been shown to affect DAT subcellular localization and since transporter activity is largely dependent on cell surface localization of DAT, protein-protein interactions have a major influence on regulating DAT activity.  Conceivably, interactions may exist that tether DAT to specific cytoskeletal components in order to be targeted to specific subcellular areas or can interact with scaffolding proteins to maintain localization to specific domains.  

My long term objective is to understand the dynamics of DAT activity by identifying components of the DAT proteome and characterize the mechanisms involved in regulating these interactions.  My immediate goals will specifically focus on the interaction between DAT and microtubule proteins.  In addition to a previous report showing an association between DAT and tubulin, we have preliminary evidence to suggest a direct interaction between the DAT and tubulin.  Therefore, to investigate the interaction between DAT and tubulin this proposal will pursue the following specific aims:

(1) characterize the interaction between DAT and tubulin

(2) identify the functional impact of the DAT-tubulin interaction on DAT activity

(3) examine the behavioural effects of disrupting the DAT-tubulin interaction.