Unique N-terminal extension domain of human asparaginyl-tRNA synthetase elicits CCR3-mediated chemokine activity

Int J Biol Macromol. 2018 Dec;120(Pt A):835-845. doi: 10.1016/j.ijbiomac.2018.08.171. Epub 2018 Aug 30.

Abstract

Asparaginyl-tRNA synthetase (NRS) is not only essential in protein translation but also associated with autoimmune diseases. Particularly, patients with antibodies that recognize NRS often develop interstitial lung disease (ILD). However, the underlying mechanism of how NRS is recognized by immune cells and provokes inflammatory responses is not well-understood. Here, we found that the crystal structure of the unique N-terminal extension domain of human NRS (named as UNE-N, where -N denotes NRS) resembles that of the chemotactic N-terminal domain of NRS from a filarial nematode, Brugia malayi, which recruits and activates specific immune cells by interacting with CXC chemokine receptor 1 and 2. UNE-N induced migration of CC chemokine receptor 3 (CCR3)-expressing cells. The chemokine activity of UNE-N was significantly reduced by suppressing CCR3 expression with CCR3-targeting siRNA, and the loop3 region of UNE-N was shown to interact mainly with the extracellular domains of CCR3 in nuclear magnetic resonance perturbation experiments. Based on these results, evolutionarily acquired UNE-N elicits chemokine activities that would promote NRS-CCR3-mediated proinflammatory signaling in ILD.

Keywords: Asparaginyl-tRNA synthetase; CC chemokine receptor 3; Chemokine.

MeSH terms

  • Animals
  • Aspartate-tRNA Ligase / chemistry*
  • Aspartate-tRNA Ligase / genetics
  • Aspartate-tRNA Ligase / immunology
  • Brugia malayi / chemistry
  • Brugia malayi / pathogenicity
  • Chemokines / chemistry
  • Chemokines / genetics
  • Chemokines / immunology
  • Crystallography, X-Ray
  • Humans
  • Inflammation / genetics*
  • Inflammation / immunology
  • Inflammation / pathology
  • Lung Diseases, Interstitial / genetics*
  • Lung Diseases, Interstitial / immunology
  • Lung Diseases, Interstitial / pathology
  • Protein Domains
  • RNA, Transfer, Amino Acyl / chemistry*
  • RNA, Transfer, Amino Acyl / genetics
  • RNA, Transfer, Amino Acyl / immunology
  • Receptors, CCR3 / chemistry*
  • Receptors, CCR3 / genetics
  • Receptors, CCR3 / immunology

Substances

  • Chemokines
  • RNA, Transfer, Amino Acyl
  • Receptors, CCR3
  • Aspartate-tRNA Ligase
  • asparaginyl-tRNA synthetase