A better structural understanding of the dopamine transporter
The title of the five-year project is “Elucidating the transport process and structural basis for drug binding to the human dopamine transporter”, and during the project two PhD students and two postdocs will be employed.
hDAT, a small molecule of great significance
Dopamine is a well-known regulator of essential brain functions such as reward, attention, risk-taking, and locomotion. The human dopamine transporter (hDAT) critically controls dopamine signaling by clearing it from the synaptic cleft.
hDAT is also the primary target for addictive substances like cocaine and amphetamine.
Despite its significance, the transporter's physiological mechanism are unclear, largely because we still need structural insights.
Cryo-electron microscopy and protein design
Claus Løland was recently spearheading a team of researchers achieving a significant breakthrough by resolving the hDAT structure with bound cocaine at 2.6 Å resolution using cryo-electron microscopy (cryo-EM).
But since this structure of hDAT binding to cocaine only gives a limited understanding of the transporter's dynamic function or its interaction with other drugs, Claus Løland will now investigate this further in his new project.
The study will aim to uncover the structural basis for hDAT’s transport process and its interactions with orthosteric and allosteric inhibitors. By determining drug-binding sites and capturing how they induce distinct conformational states through cryo-EM, Claus Løland will investigate how hDAT transitions between these states during transport.
In addition, he will be using protein design to convert hDAT to a fluorescent beacon reporting on the transporter’s spatio-temporal conformational dynamics. Together, the findings will integrate structural data with protein conformational dynamics and revealing key mechanisms of dopamine transport, interconversion rates, and associated energy barriers.