This Project will continue to provide the entire PPG with an increasingly integrative structural context for the proposed studies that seek an understanding of the functional mechanisms of the neurotransmitter transporters (NTs), and of interactions with cellular components that regulate their function and integrate it into the cell signaling processes. The mechanisms of interest underiie observable pharmacological properties and physiological effects of drugs of abuse, and make these NTs both a target for the design of therapeutic drugs, and a key element in (i)-the determinants, (ii)-the effects, and (iii)-the undesirable consequences, of substance abuse. We will use computational modeling and simulation to determine the conformational changes in the TM domains of NTs that are involved in the allosteric coupling between ligand and ion transport in DAT and other NT, and the changes produced by the psychostimulants amphetamine and cocaine, based on the hypothesis that the allosteric mechanism consist of a conserved spatial network of interactions among residues positioned non-sequentially in the transporters, which are triggered in a defined temporal sequence identifiable from the SMD simulations and extensive MD equilibrations of the resulting intermediate states. We also aim for a mechanistic characterization of the N- and C-terminal segments ofthe NTs DAT and SERT, in different functional states ofthe proteins (e.g, as induced by drugs of abuse), based on a hypothesis that functional roles of these segments depend on (i)-specific confor?? mations they adopt in different functional states, and (ii)-modulation of these conformations by cellular processes involving phosphorylation, and/or (scaffold and adaptor) protein binding. We will model and simulate computationally the functional determinants of such scaffold, adaptor and membrane remodeling domains that interact with the NTs in mechanisms of signaling and trafficking in the membrane environment. To this end will study biophysical properties, mechanisms of oligomerization, and dynamic regulation of several protein families including (i) PDZ-containing multidomain proteins (e.g., PICK1);(ii) BAR domains and their complexes with specific membrane regions;(iii) membrane-inserted proteins such as Flotillin 1.

Public Health Relevance

; The neurotransmitter transporters are targets for medication such as antidepressants and anti-anxiety drugs, but are also responsible for the abuse potential of many drugs including cocaine, amphetamine, and related psychostimulants. Based on new molecular structures and powerful methods of biophysics used in modeling with computation, we are trying to understand how these transporters function, what the effects of drugs are on these function, and how thev are regulated in health and in disease

National Institute of Health (NIH)
National Institute on Drug Abuse (NIDA)
Research Program Projects (P01)
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Special Emphasis Panel (ZRG1-MDCN-G)
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Weill Medical College of Cornell University
New York
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Billesbølle, Christian B; Mortensen, Jonas S; Sohail, Azmat et al. (2016) Transition metal ion FRET uncovers K(+) regulation of a neurotransmitter/sodium symporter. Nat Commun 7:12755
Vuorenpää, Anne; Jørgensen, Trine N; Newman, Amy H et al. (2016) Differential Internalization Rates and Postendocytic Sorting of the Norepinephrine and Dopamine Transporters Are Controlled by Structural Elements in the N Termini. J Biol Chem 291:5634-51
Khelashvili, George; Schmidt, Solveig Gaarde; Shi, Lei et al. (2016) Conformational Dynamics on the Extracellular Side of LeuT Controlled by Na+ and K+ Ions and the Protonation State of Glu290. J Biol Chem 291:19786-99
Freyberg, Zachary; Sonders, Mark S; Aguilar, Jenny I et al. (2016) Mechanisms of amphetamine action illuminated through optical monitoring of dopamine synaptic vesicles in Drosophila brain. Nat Commun 7:10652
Stolzenberg, Sebastian; Michino, Mayako; LeVine, Michael V et al. (2016) Computational approaches to detect allosteric pathways in transmembrane molecular machines. Biochim Biophys Acta 1858:1652-62
Zhao, Yiming; Fay, François; Hak, Sjoerd et al. (2016) Augmenting drug-carrier compatibility improves tumour nanotherapy efficacy. Nat Commun 7:11221
Apuschkin, Mia; Stilling, Sara; Rahbek-Clemmensen, Troels et al. (2015) A novel dopamine transporter transgenic mouse line for identification and purification of midbrain dopaminergic neurons reveals midbrain heterogeneity. Eur J Neurosci 42:2438-54
Billesbølle, Christian B; Krüger, Mie B; Shi, Lei et al. (2015) Substrate-induced unlocking of the inner gate determines the catalytic efficiency of a neurotransmitter:sodium symporter. J Biol Chem 290:26725-38
Khelashvili, George; Doktorova, Milka; Sahai, Michelle A et al. (2015) Computational modeling of the N-terminus of the human dopamine transporter and its interaction with PIP2 -containing membranes. Proteins 83:952-69
Stolzenberg, Sebastian; Quick, Matthias; Zhao, Chunfeng et al. (2015) Mechanism of the Association between Na+ Binding and Conformations at the Intracellular Gate in Neurotransmitter:Sodium Symporters. J Biol Chem 290:13992-4003

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