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

Hum Mutat. 2018 Mar;39(3):415-432. doi: 10.1002/humu.23380. Epub 2017 Dec 26.


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.

Keywords: Charcot-Marie-Tooth disease type 2W; aminoacyl-tRNA synthetase; hereditary motor and sensory neuropathy; histidyl-tRNA synthetase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aminoacylation
  • Axons / pathology*
  • Biocatalysis
  • Catalytic Domain
  • Conserved Sequence
  • Female
  • Genetic Complementation Test
  • Histidine-tRNA Ligase / chemistry
  • Histidine-tRNA Ligase / genetics
  • Histidine-tRNA Ligase / isolation & purification
  • Histidine-tRNA Ligase / metabolism*
  • Humans
  • Kinetics
  • Male
  • Mutation / genetics
  • Pedigree
  • Peripheral Nervous System Diseases / enzymology*
  • Peripheral Nervous System Diseases / genetics
  • Peripheral Nervous System Diseases / pathology*
  • Protein Multimerization
  • Substrate Specificity


  • Histidine-tRNA Ligase