Characterizing CMT-causing variants in tryptophanyl- tRNA synthetase

Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that link amino acids to their cognate tRNAs. Neurological conditions, such as Charcot-Marie-Tooth (CMT) disease, have been linked to variants identified in these enzymes. I created a humanized yeast model to assess the underlying disease-causing mechanism associated with two CMT variants, H257R and D314G, present in the human tryptophanyl-tRNA synthetase (WARS1). Using proteomic analysis, protein biochemistry, and yeast growth assays, I found that while both variants retain their typical structure, their stability and function differ. D314G exhibited decreased stability and triggers stress- related pathways, whereas H257R showed mild functional impairment that can be ameliorated by tryptophan supplementation. This work presents the first WARS1 humanized yeast model that was subsequently used to better understand the disease- causing molecular mechanism of WARS1 variants and investigate potential therapeutic approaches, such as amino acid supplementation.

Name thesis:degree_name

M Sc

Discipline thesis:degree_discipline

Biochemistry

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2025

Author dc:creator

• Wu, Fanqi

Advisor dc:contributor.advisor

• Heinemann, Ilka

• WARS1
• aminoacyl-tRNA synthetase
• neuropathy
• Charcot-Marie-Tooth disease
• yeast model
• proteomics
• protein stability.

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/39363

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/39363