Mutation of tyrosine 470 of human dopamine transporter is critical for HIV-1 tat-induced inhibition of dopamine transport and transporter conformational transitions

Narasimha M. Midde, Xiaoqin Huang, Adrian M. Gomez, Rosemarie M. Booze, Chang Guo Zhan, Jun Zhu

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

HIV-1 Tat protein plays a crucial role in perturbations of the dopamine (DA) system. Our previous studies have demonstrated that Tat decreases DA uptake, and allosterically modulates DA transporter (DAT) function. In the present study, we have found that Tat interacts directly with DAT, leading to inhibition of DAT function. Through computational modeling and simulations, a potential recognition binding site of human DAT (hDAT) for Tat was predicted. Mutation of tyrosine470 (Y470H) attenuated Tat-induced inhibition of DA transport, implicating the functional relevance of this residue for Tat binding to hDAT. Y470H reduced the maximal velocity of [3H]DA uptake without changes in the Km and IC50 values for DA inhibition of DA uptake but increased DA uptake potency for cocaine and GBR12909, suggesting that this residue does not overlap with the binding sites in hDAT for substrate but is critical for these inhibitors. Furthermore, Y470H also led to transporter conformational transitions by affecting zinc modulation of DA uptake and WIN35,428 binding as well as enhancing basal DA efflux. Collectively, these findings demonstrate Tyr470 as a functional recognition residue in hDAT for Tat-induced inhibition of DA transport and transporter conformational transitions. The consequence of mutation at this residue is to block the functional binding of Tat to hDAT without affecting physiological DA transport.

Original languageEnglish
Pages (from-to)975-987
Number of pages13
JournalJournal of NeuroImmune Pharmacology
Volume8
Issue number4
DOIs
StatePublished - Sep 2013

Bibliographical note

Funding Information:
Acknowledgements This research was supported by grants from the National Institutes of Health to Jun Zhu (DA024275, DA026721), Chang-Guo Zhan (DA032910, DA035552), and Rosemarie Booze (DA013137, HD043680).

Keywords

  • Allosteric modulation
  • Computational modeling
  • Dopamine transporter
  • HIV-1 Tat
  • Mutation
  • Uptake

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Immunology and Allergy
  • Immunology
  • Pharmacology

Fingerprint

Dive into the research topics of 'Mutation of tyrosine 470 of human dopamine transporter is critical for HIV-1 tat-induced inhibition of dopamine transport and transporter conformational transitions'. Together they form a unique fingerprint.

Cite this