scholarly journals Mutations of Human DopamineTransporter at Tyrosine88, Aspartic Acid206, and Histidine547 Influence Basal and HIV-1 Tat‐inhibited Dopamine Transport

2021 ◽  
Author(s):  
Pamela M. Quizon ◽  
Yaxia Yuan ◽  
Yike Zhu ◽  
Yi Zhou ◽  
Matthew J. Strauss ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Inhibitory Effect ◽  
Conformational State ◽  
Dopamine Uptake ◽  
Maximal Velocity ◽  
Wild Type ◽  
Allosteric Interaction ◽  
Dopamine Transport ◽  
Transactivator Of Transcription ◽  
Hiv 1

AbstractHIV-1 transactivator of transcription (Tat) has a great impact on the development of HIV-1 associated neurocognitive disorders through disrupting dopamine transmission. This study determined the mutational effects of human dopamine transporter (hDAT) on basal and Tat-induced inhibition of dopamine transport. Compared to wild-type hDAT, the maximal velocity (Vmax) of [3H]dopamine uptake was decreased in D381L and Y88F/D206L/H547A, increased in D206L/H547A, and unaltered in D206L. Recombinant TatR1 − 86 inhibited dopamine uptake in wild-type hDAT, which was attenuated in either DAT mutants (D206L, D206L/H547A, and Y88F/D206L/H547A) or mutated TatR1 − 86 (K19A and C22G), demonstrating perturbed Tat-DAT interaction. Mutational effects of hDAT on the transporter conformation were evidenced by attenuation of zinc-induced increased [3H]WIN35,428 binding in D206L/H547A and Y88F/D206A/H547A and enhanced basal MPP+ efflux in D206L/H547A. H547A-induced outward-open transport conformational state was further validated by enhanced accessibility to MTSET ([2-(trimethylammonium)ethyl]-methanethiosulfonate) of an inserted cysteine (I159C) on a hDAT background.. Furthermore, H547A displayed an increase in palmitoylation inhibitor-induced inhibition of dopamine uptake relative to wide-type hDAT, indicating a change in basal palmitoylation in H547A. These results demonstrate that Y88F, D206L, and H547A attenuate Tat inhibition while preserving DA uptake, providing insights into identifying targets for improving DAT-mediated dopaminergic dysregulation. Graphical Abstract HIV-1 Tat inhibits dopamine uptake through human dopamine transporter (hDAT) on the presynaptic terminal through a direct allosteric interaction. Key hDAT residues D-H547, D-Y88, and D-D206 are predicted to be involved in the HIV-1 Tat-DAT binding. Mutating these residues attenuates this inhibitory effect by disrupting the Tat-hDAT interaction

scholarly journals Mutational effects of human dopamine transporter at tyrosine88, lysine92, and histidine547 on basal and HIV-1 Tat-inhibited dopamine transport

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wei-Lun Sun ◽  
Pamela M. Quizon ◽  
Yaxia Yuan ◽  
Matthew J. Strauss ◽  
Richard McCain ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Dopamine Transport ◽  
Hiv 1

scholarly journals Mutations at Tyrosine 88, Lysine 92 and Tyrosine 470 of Human Dopamine Transporter Result in an Attenuation of HIV-1 Tat-Induced Inhibition of Dopamine Transport

2015 ◽  
Vol 10 (1) ◽  
pp. 122-135 ◽  
Author(s):  
Narasimha M. Midde ◽  
Yaxia Yuan ◽  
Pamela M. Quizon ◽  
Wei-Lun Sun ◽  
Xiaoqin Huang ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Dopamine Transport ◽  
Hiv 1

scholarly journals Molecular mechanism: the human dopamine transporter histidine 547 regulates basal and HIV-1 Tat protein-inhibited dopamine transport

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Pamela M. Quizon ◽  
Wei-Lun Sun ◽  
Yaxia Yuan ◽  
Narasimha M. Midde ◽  
Chang-Guo Zhan ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Dopamine Transporter ◽  
Tat Protein ◽  
Dopamine Transport ◽  
Hiv 1

scholarly journals Role of Histidine 547 of Human Dopamine Transporter in Molecular Interaction with HIV-1 Tat and Dopamine Uptake

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yaxia Yuan ◽  
Pamela M. Quizon ◽  
Wei-Lun Sun ◽  
Jianzhuang Yao ◽  
Jun Zhu ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Molecular Interaction ◽  
Dopamine Uptake ◽  
Hiv 1

scholarly journals Mutation of Tyrosine 470 of Human Dopamine Transporter is Critical for HIV-1 Tat-Induced Inhibition of Dopamine Transport and Transporter Conformational Transitions

2013 ◽  
Vol 8 (4) ◽  
pp. 975-987 ◽  
Author(s):  
Narasimha M. Midde ◽  
Xiaoqin Huang ◽  
Adrian M. Gomez ◽  
Rosemarie M. Booze ◽  
Chang-Guo Zhan ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Conformational Transitions ◽  
Dopamine Transport ◽  
Hiv 1

Exocyst-dependent trafficking of the wild-type dopamine transporter

2016 ◽  
Vol 4 (Suppl. 3) ◽  
pp. A4.6
Author(s):  
H. M. Mazhar Asjad
Keyword(s):  
Dopamine Transporter ◽  
Wild Type

Molecular and genetic characterization of natural variants of HIV-1 Nef gene from North India and its functional implication in down-regulation of MHC-I and CD-4

2020 ◽  
Vol 18 ◽  
Author(s):  
J. Singh ◽  
L. Ronsard ◽  
M. Pandey ◽  
R. Kapoor ◽  
V.G. Ramachandran ◽  
...  
Keyword(s):  
Biological Activities ◽  
Sequence Similarity ◽  
Eukaryotic Expression ◽  
North India ◽  
Cell Surface Expression ◽  
Functional Domains ◽  
Wild Type ◽  
Down Regulation ◽  
Subtype B ◽  
Hiv 1

Background: HIV-1 Nef is an important accessory protein with multiple effector functions. Genetic studies of HIV-1 Nef gene shows extensive genetic diversity and the functional studies have been carried out mostly with Nef derived from regions dominated by subtype B (North America & Europe). Objective: This study was carried out to characterize genetic variations of the Nef gene from HIV-1 infected individuals from North-India and to find out their functional implications. Methods: The unique representative variants were sub-cloned in eukaryotic expression vector and further characterized with respect to their ability to down regulate cell surface expression of CD4 and MHC-1molecules. Results: The phylogenetic analysis of Nef variants revealed sequence similarity with either consensus subtype B or B/C recombinants. Boot scan analysis of some of our variants showed homology to B/C recombinant and some to wild type Nef B. Extensive variations were observed in most of the variants. The dN/dS ratio revealed 80% purifying selection and 20% diversifying selection implying the importance of mutations in Nef variants. Intracellular stability of Nef variants differed greatly when compared with wild type Nef B and C. There were some variants that possessed mutations in the functional domains of Nef and responsible for its differential CD4 and MHC-1 down regulation activity. Conclusion: We observed enhanced biological activities in some of the variants, perhaps arising out of amino acid substitutions in their functional domains. The CD4 and MHC-1 down-regulation activity of Nef is likely to confer immense survival advantage allowing the most rare genotype in a population to become the most abundant after a single selection event.

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