Single Quantum Dot Tracking Unravels Agonist Effects on the Dopamine Receptor Dynamics
| Autor: | Oleg Kovtun, Ruben Torres, Sandra J. Rosenthal, Travis Josephs, Riley S. Ferguson |
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| Rok vydání: | 2020 |
| Předmět: |
Gene isoform
Agonist 0303 health sciences Receptors Dopamine D2 Drug discovery medicine.drug_class Chemistry 030302 biochemistry & molecular biology Dopaminergic Ligands Actin cytoskeleton Biochemistry Molecular Imaging 03 medical and health sciences HEK293 Cells Quinpirole Dopamine receptor Dopamine Agonists Quantum Dots medicine Biophysics Humans Receptor medicine.drug |
| Zdroj: | Biochemistry. 60:1031-1043 |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | D2 dopamine receptors (DRD2s) belong to a family of G protein-coupled receptors that modulate synaptic dopaminergic tone via regulation of dopamine synthesis, storage, and synaptic release. DRD2s are the primary target for traditional antipsychotic medications; dysfunctional DRD2 signaling has been linked to major depressive disorder, attention-deficit hyperactivity disorder, addiction, Parkinson's, and schizophrenia. DRD2 lateral diffusion appears to be an important post-translational regulatory mechanism; however, the dynamic response of DRD2s to ligand-induced activation is poorly understood. Dynamic imaging of the long isoform of DRD2 (D2L) fused to an N-terminal antihemagglutinin (HA) epitope and transiently expressed in HEK-293 cells was achieved through a combination of a high-affinity biotinylated anti-HA antigen-binding fragment (Fab) and streptavidin-conjugated quantum dots (QD). Significant reduction (∼40%) in the rate of lateral diffusion of QD-tagged D2L proteins was observed under agonist (quinpirole; QN)-stimulated conditions compared to basal conditions. QN-induced diffusional slowing was accompanied by an increase in frequency, lifetime, and confinement of temporary arrest of lateral diffusion (TALL), an intrinsic property of single receptor lateral motion. The role of the actin cytoskeleton in QN-induced diffusional slowing of D2L was also explored. The observed dynamic changes appear to be a sensitive indicator of the receptor activity status and might also spatially and temporally shape the receptor-mediated downstream signaling. This dynamic information could potentially be useful in informing drug discovery efforts based on single-molecule pharmacology. |
| Databáze: | OpenAIRE |
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