A mechanism of uncompetitive inhibition of the serotonin transporter
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, Austria
- Department of Neurobiology, University of Vienna, Austria
- Center for Brain Research, Medical University of Vienna, Austria
Figures
Figure 1
Inhibition of serotonin transporter (SERT)-mediated [3H]5-HT uptake by cocaine, noribogaine, and ECSI#6.
(A) The chemical structures of cocaine, noribogaine, and ECSI#6. (B–D) HEK293 cells stably expressing wild-type YFP-SERT (~30,000 per well) were seeded onto 96-well plates. After 24 hr, inhibition …
Figure 2
Inhibition of [3H]citalopram binding by cocaine, noribogaine, and ECSI#6.
(A–G) Inhibition of [3H]citalopram binding to serotonin transporter (SERT) by cocaine (A, D; blue curves), noribogaine (B, E; green curves), or ECSI#6 (C, F; red curves). The binding inhibition …
Figure 3
Different modes of inhibition by cocaine, noribogaine, and ECSI#6 of substrate uptake by serotonin transporter (SERT).
HEK293 cells stably expressing YFP-SERT (30,000/well) were preincubated in buffer in the absence (control, black circles) or presence of the indicated concentrations of cocaine (A), noribogaine (B), …
Figure 4
Kinetics of current inhibition by cocaine, noribogaine, and ECSI#6.
Single HEK293 cells stably expressing GFP-serotonin transporter (SERT) were voltage-clamped to –60 mV using the whole-cell patch clamp technique under physiological ionic gradients. (A) …
Figure 5
ECSI#6 can rescue folding-deficient SERT-PG601-602AA.
[3H]5-HT uptake by and glycosylation pattern of hSERT-PG601,602AA expressed in HEK293 cells incubated with cocaine, noribogaine, or ECSI#6. (A) Comparison of [3H]5-HT uptake by HEK293 cells …
Figure 6
ECSI#6 and noribogaine modulate presynaptic expression of hSERT-PG 601,602 AA in the adult fly brain.
The top row (A–A’’) shows the expression of membrane-anchored GFP in the presynaptic compartment of serotonergic neurons in distinct fan-shaped body (FB) layers (dotted circle) co-labeled with an …
Figure 7
Conformational preference of cocaine, noribogaine, and ECSI#6 for binding to serotonin transporter (SERT).
(A) Reaction scheme (black) of a simple kinetic model of substrate transport by the SERT. The chosen microscopic rate constants were as follows: kon(K+)=106 M–1 s–1, koff(K+)=5000 s–1, kon(Na+)=106 …
Figure 8
Interrogating the kinetic model to analyze the inhibition of substrate transport by serotonin transporter (SERT) by noribogaine and ECSI#6.
(A and B) Simulations of the saturation kinetics of SERT in the presence of the indicated concentrations of noribogaine (A) or ECSI#6 (B). The curves were generated using the reaction scheme …
