Drosophila melanogaster: a novel animal model for the behavioral characterization of autism-associated mutations in the dopamine transporter gene

Abstract

The studies by Hamilton and Campbell et al. describe the first autism spectrum disorder-associated de novo mutation in the human dopamine (DA) transporter (hDAT) gene. This mutation results in a Thr356 (highlighted in green) to Met (highlighted in gray) substitution in a region of the hDAT implicated in ion and substrate binding. The authors of this study report that this de novo mutation causes profound hDAT functional abnormalities. In Drosophila melanogaster, a behavioral assay was developed in order to mechanistically test the molecular discoveries in vivo. Flies expressing the mutant hDAT display anomalous locomotion (representative ambulatory vector shown above, in red). Graphical renderings by Andy Hamilton (CREAM creative, Boston, MA, USA; andy@thecreamcreative.com). For more information on this topic, please refer to the article by Hamilton et al. on pages 1315-1323.

The Role of Dopamine in the Stimulant Characteristics of Novel Psychoactive Substances (NPS)—Neurobiological and Computational Assessment Using the Case of Desoxypipradrol (2-DPMP)

“…A standard protocol was used to study these docked homology models of rat DAT (rDAT) based on the crystal structure of the Drosophila Melanogaster dopamine transporter (dDAT) with all-atom MD simulations in explicit models of the hydrated lipid membrane environment (Hamilton et al, 2013;Hansen et al, 2014;Khelashvili et al, 2015a;Khelashvili et al, 2015b;Sahai et al, 2017;Sahai et al, 2018). To summarize, a multistep equilibration protocol was performed with the NAMD software, version 2.13 (Phillips et al, 2005), to remove the close contacts in the structure, the backbones were initially fixed and then harmonically constrained, and water was restrained by small forces from penetrating the protein-lipid interface.…”

Transition metal ion FRET uncovers K+ regulation of a neurotransmitter/sodium symporter

“…LeuT has been used as the principal model system for studying NSS structure–function relationships 16 24 and has served as template for homology models that have guided, for example, binding site mapping in mammalian NSSs 25 26 27 28 . In addition, dynamic inferences about conformational transitions in the NSS transport cycle have been obtained using LeuT as model in studies using biophysical techniques such as double electron–electron resonance 29 30 31 , single molecule fluorescence resonance energy transfer (smFRET) 32 33 and site-directed fluorescence quenching spectroscopy 34 . Nonetheless, despite a growing mechanistic understanding of the translocation process, none of the studies have suggested a putative role of K + and thus addressed the question whether the counter-transport of K + proposed for SERT 8 35 is indicative of a general regulatory role of K + in other NSS proteins.…”

Autism Spectrum Disorder-Related Syndromes: Modeling with Drosophila and Rodents

“…The Drosophila activity assay is commonly used to evaluate the activity and circadian sleep–wake rhythm of ASD model flies [94,95]. Newly eclosed adult male flies were used in this assay.…”

“…DAT is a presynaptic membrane protein that regulates dopamine homeostasis in the CNS by mediating the re-uptake of released dopamine in synapses. A Drosophila model expressing hDAT carrying the T356M mutation has been established [94]. The dopaminergic neuron-specific expression of hDAT T356M under the background of the Drosophila DAT gene mutation induced hyperlocomotion activity in adult flies that was monitored by the activity assay (Trikinetics), reflecting a characteristic of ASD [94].…”