Logo image
Substrate interaction defects in histidyl-tRNA synthetase linked to dominant axonal peripheral neuropathy
Journal article   Open access   Peer reviewed

Substrate interaction defects in histidyl-tRNA synthetase linked to dominant axonal peripheral neuropathy

Jamie A Abbott, Rebecca Meyer-Schuman, Vincenzo Lupo, Shawna Feely, Inès Mademan, Stephanie N Oprescu, Laurie B Griffin, M Antonia Alberti, Carlos Casasnovas, Sharon Aharoni, …
Human mutation, Vol.39(3), pp.415-432
03/2018
DOI: 10.1002/humu.23380
PMCID: PMC5983030
PMID: 29235198
url
https://doi.org/10.1002/humu.23380View
Published (Version of record) Open Access

Abstract

Histidyl-tRNA synthetase (HARS) ligates histidine to cognate tRNA molecules, which is required for protein translation. Mutations in HARS cause the dominant axonal peripheral neuropathy Charcot-Marie-Tooth disease type 2W (CMT2W); however, the precise molecular mechanism remains undefined. Here, we investigated three HARS missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The three mutations localize to the HARS catalytic domain and failed to complement deletion of the yeast ortholog (HTS1). Enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultracentrifugation (AUC) were employed to assess the effect of these substitutions on primary aminoacylation function and overall dimeric structure. Notably, the p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly HARS substitutions all led to reduced aminoacylation, providing a direct connection between CMT2W-linked HARS mutations and loss of canonical ARS function. While DSF assays revealed that only one of the variants (p.Val155Gly) was less thermally stable relative to wild-type, all three HARS mutants formed stable dimers, as measured by AUC. Our work represents the first biochemical analysis of CMT-associated HARS mutations and underscores how loss of the primary aminoacylation function can contribute to disease pathology.
Amino Acid Sequence Aminoacylation Catalytic Domain Histidine-tRNA Ligase - metabolism Biocatalysis Humans Protein Multimerization Peripheral Nervous System Diseases - enzymology Substrate Specificity Male Mutation - genetics Genetic Complementation Test Histidine-tRNA Ligase - chemistry Histidine-tRNA Ligase - genetics Histidine-tRNA Ligase - isolation & purification Pedigree Axons - pathology Conserved Sequence Female Peripheral Nervous System Diseases - pathology Kinetics Peripheral Nervous System Diseases - genetics

Details

Metrics

Logo image