Reinvestigation of aminoacyl-tRNA synthetase core complex by affinity purification-mass spectrometry reveals TARSL2 as a potential member of the complex

PLoS One. 2013 Dec 2;8(12):e81734. doi: 10.1371/journal.pone.0081734. eCollection 2013.

Abstract

Twenty different aminoacyl-tRNA synthetases (ARSs) link each amino acid to their cognate tRNAs. Individual ARSs are also associated with various non-canonical activities involved in neuronal diseases, cancer and autoimmune diseases. Among them, eight ARSs (D, EP, I, K, L, M, Q and RARS), together with three ARS-interacting multifunctional proteins (AIMPs), are currently known to assemble the multi-synthetase complex (MSC). However, the cellular function and global topology of MSC remain unclear. In order to understand the complex interaction within MSC, we conducted affinity purification-mass spectrometry (AP-MS) using each of AIMP1, AIMP2 and KARS as a bait protein. Mass spectrometric data were funneled into SAINT software to distinguish true interactions from background contaminants. A total of 40, 134, 101 proteins in each bait scored over 0.9 of SAINT probability in HEK 293T cells. Complex-forming ARSs, such as DARS, EPRS, IARS, Kars, LARS, MARS, QARS and RARS, were constantly found to interact with each bait. Variants such as, AIMP2-DX2 and AIMP1 isoform 2 were found with specific peptides in KARS precipitates. Relative enrichment analysis of the mass spectrometric data demonstrated that TARSL2 (threonyl-tRNA synthetase like-2) was highly enriched with the ARS-core complex. The interaction was further confirmed by coimmunoprecipitation of TARSL2 with other ARS core-complex components. We suggest TARSL2 as a new component of ARS core-complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Amino Acid Sequence
  • Amino Acyl-tRNA Synthetases / chemistry*
  • Amino Acyl-tRNA Synthetases / metabolism*
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism
  • Chromatography, Affinity*
  • Computational Biology / methods*
  • Cytokines / chemistry
  • Cytokines / metabolism
  • HEK293 Cells
  • Humans
  • Lysine-tRNA Ligase / metabolism
  • Mass Spectrometry*
  • Molecular Sequence Data
  • Neoplasm Proteins / chemistry
  • Neoplasm Proteins / metabolism
  • Nuclear Proteins
  • Protein Interaction Mapping / methods*
  • Protein Processing, Post-Translational
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / metabolism
  • Threonine-tRNA Ligase / analysis*
  • Threonine-tRNA Ligase / isolation & purification
  • Threonine-tRNA Ligase / metabolism*

Substances

  • AIMP2 protein, human
  • Carrier Proteins
  • Cytokines
  • Neoplasm Proteins
  • Nuclear Proteins
  • RNA-Binding Proteins
  • small inducible cytokine subfamily E, member 1
  • Amino Acyl-tRNA Synthetases
  • TARS3 protein, human
  • Threonine-tRNA Ligase
  • Lysine-tRNA Ligase

Grant support

This study was supported by grants from the Biomedical Convergence Global Frontier program and the Proteogenomics Research program funded by MEST, and a KIST intramural program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.