1. Academic Validation
  2. Restoration of the GTPase activity and cellular interactions of Gαo mutants by Zn2+ in GNAO1 encephalopathy models

Restoration of the GTPase activity and cellular interactions of Gαo mutants by Zn2+ in GNAO1 encephalopathy models

  • Sci Adv. 2022 Oct 7;8(40):eabn9350. doi: 10.1126/sciadv.abn9350.
Yonika A Larasati 1 Mikhail Savitsky 1 Alexey Koval 1 Gonzalo P Solis 1 Jana Valnohova 1 Vladimir L Katanaev 1 2
Affiliations

Affiliations

  • 1 Translational Research Centre in Oncohaematology, Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, CH-1211 Geneva, Switzerland.
  • 2 Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690090 Vladivostok, Russia.
Abstract

De novo point mutations in GNAO1, gene encoding the major neuronal G protein Gαo, have recently emerged in patients with pediatric encephalopathy having motor, developmental, and epileptic dysfunctions. Half of clinical cases affect codons Gly203, Arg209, or Glu246; we show that these mutations accelerate GTP uptake and inactivate GTP hydrolysis through displacement Gln205 critical for GTP hydrolysis, resulting in constitutive GTP binding by Gαo. However, the mutants fail to adopt the activated conformation and display aberrant interactions with signaling partners. Through high-throughput screening of approved drugs, we identify zinc pyrithione and Zn2+ as agents restoring active conformation, GTPase activity, and cellular interactions of the encephalopathy mutants, with negligible effects on wild-type Gαo. We describe a Drosophila model of GNAO1 encephalopathy where dietary zinc restores the motor function and longevity of the mutant flies. Zinc supplements are approved for diverse human neurological conditions. Our work provides insights into the molecular etiology of GNAO1 encephalopathy and defines a potential therapy for the patients.

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