Quantum dots reveal heterogeneous membrane diffusivity and dynamic surface density polarization of dopamine transporter

• Published in: PloS one Vol. 14; no. 11; p. e0225339
• Main Authors: Kovtun, Oleg, Tomlinson, Ian D., Ferguson, Riley S., Rosenthal, Sandra J.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21.11.2019; Public Library of Science (PLoS)
• Subjects: Algorithms; Amphetamines; Animals; Biology and Life Sciences; Cell Membrane - chemistry; Cell Membrane - metabolism; Cell membranes; Cell surface; Chemistry; Cholesterol; Cocaine; Coding; Conformation; Diffusion rate; Diffusivity; Dopamine; Dopamine Plasma Membrane Transport Proteins - chemistry; Dopamine Plasma Membrane Transport Proteins - metabolism; Dopamine transporter; Electronics; Engineering; HEK293 Cells; Humans; Kinases; Localization; Membranes; Microscopy; Models, Theoretical; Mutants; Neural coding; Neuroimaging; Phenols (Class of compounds); Physical Sciences; Proteins; Quantum Dots; Reproducibility of Results; Sperm; Structure-Activity Relationship; Tracking; United States > US; Tennessee; Nashville Tennessee
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0225339

The presynaptic dopamine transporter mediates rapid reuptake of synaptic dopamine. Although cell surface DAT trafficking recently emerged as an important component of DAT regulation, it has not been systematically investigated. Here, we apply our single quantum dot (Qdot) tracking approach to monitor DAT plasma membrane dynamics in several heterologous expression cell hosts with nanometer localization accuracy. We demonstrate that Qdot-tagged DAT proteins exhibited highly heterogeneous membrane diffusivity dependent on the local membrane topography. We also show that Qdot-tagged DATs were localized away from the flat membrane regions and were dynamically retained in the membrane protrusions and cell edges for the duration of imaging. Single quantum dot tracking of wildtype DAT and its conformation-defective coding variants (R60A and W63A) revealed a significantly accelerated rate of dysfunctional DAT membrane diffusion. We believe our results warrant an in-depth investigation as to whether compromised membrane dynamics is a common feature of brain disorder-derived DAT mutants.