Transcriptome analysis reveals stimulus-specific functions of glutamylprolyl-tRNA synthetase

Abstract

The aminoacyl-tRNA synthetases (ARSs) are ancient house-keeping enzymes that catalyze the ligation of tRNAs to their cognate amino acids in the first step of protein synthesis. During the evolution of higher eukaryotes, cytoplasmic ARSs have undergone significant changes including the addition of new domains that are not part of the enzymatic core. These additional regions have been found to be associated with a broad range of biological functions beyond protein synthesis. The non-translational functions of ARSs appear to be regulated by their presence within a cytoplasmic multi-tRNA synthetase complex (MSC), which is assembled through the appended domains. We recently reported that the MSC member glutamylprolyl-tRNA synthetase (EPRS) promotes antiviral gene expression through its infection-specific phosphorylation and release from the MSC. Here, we conducted transcriptome analysis of influenza A virusinfected cells. We particularly focused on the analysis of chemokine-related gene expression, in combination with chemokine array analysis against virus infection. Moreover, the correlation between chemokine expression pattern and EPRS function in response to different stimuli was assessed. The results showed that viral infection increases interferon-response and pro-inflammatory chemokine expression. In contrast, the level of chemokine expression was suppressed in interferon-γ treated cells. Thus, these results further demonstrate the previously reported stimulus-specific EPRS functions in immune responses.