Rescueing sleepless flies – Pharmacochaperoning of folding-deficient dopamine transporters, which give rise to infantile dystonia/Parkinsonism

• Autorzy: Freissmuth M. , El- Kasaby A. , Kasture A. , Asjad H.M.M. , Sucic S.
• Języki publikacji: EN

Abstrakty

EN

Folding-defective mutants of the human dopamine transporter (DAT) cause a syndrome of infantile dystonia/Parkinsonism. We provide a proof-of-principle that the folding‑deficit is amenable to correction in vivo by two means, the cognate DAT ligand noribogaine and the HSP70 inhibitor, pifithrin‑µ: a mutation in the gene encoding dDAT was identified in the Zuker collection of Drosophila melanogaster, which leads to a sleepless phenotype in flies harboring the mutation dDAT‑G108Q. We examined the structure of dDAT‑G108Q by molecular dynamics simulations using the published crystal structure of dDAT as a starting point. These simulation provided evidence for structural instability of dDAT‑G108Q consistent with a folding defect. We verified this conjecture by visulaizing heterologously expressed dDAT‑G108Q and the human equivalent hDAT‑G140Q in the endoplasmic reticulum and by showing that it was found in a complex with endogenous folding sensors (calnexin and HSP70-1A). Incubation of the cells with noribogaine (a DAT ligand selective for the inward facing state) and/or pifithrin‑µ (an HSP70‑inhibtor) restored folding of, and hence dopamine transport by, dDAT‑G108Q and of hDAT‑G140Q. The mutated versions of DAT were confined to the cell bodies of the dopaminergic neurons in the fly brain and failed to reach the axonal compartments. Axonal delivery was restored and sleep time increased to normal length (from 300 to 1000 min/d), if dDAT‑G108Q expressing flies were treated with noribogaine and/or pifithrin‑µ. Rescuing misfolded versions of DAT by pharmacochaperoning is of therapeutic interest: it may provide opportunities to remedy disorders arising from folding-defective mutants of human DAT and of other related SLC6 transporters, e.g. of the human creatine transporter-1, which gives rise to mental retardation when mutated at the equivalent glycine residue. FINANCIAL SUPPORT: SFB35-10 by the Austrian Science Fund/FWF.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.20-21

Twórcy

autor

Freissmuth M.

• Institute of Pharmacology, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria

autor

El- Kasaby A.

• Institute of Pharmacology, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria

autor

Kasture A.

• Institute of Pharmacology, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria

autor

Asjad H.M.M.

• Institute of Pharmacology, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria

autor

Sucic S.

• Institute of Pharmacology, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria