Cytoplasmic aminoacyl-tRNA synthetases (ARSs) are organized into multi-tRNA synthetase complexes (MSCs), from Archaea to mammals. An evolutionary conserved role of the MSCs is enhancement of aminoacylation by forming stable associations of the ARSs and tRNAs. In mammals, a single macromolecular MSC exists, which is composed of eight cytoplasmic ARSs, for nine amino acids, and three scaffold proteins. Consequently, nearly half of aminoacyl-tRNA efflux becomes concentrated at the MSC. Stable supply of aminoacyl-tRNA to the ribosome is, therefore, considered to be a major role of the mammalian MSC. Furthermore, the mammalian MSC also serves as a reservoir for releasable components with noncanonical functions. In this study, a split-luciferase complementation system was applied to investigate the configuration of the MSC in live mammalian cells. Multiplex interconnections between the components were simplified into binary protein-protein interactions, and pairwise comparison of the interactions reconstituted a framework consistent with previous in vitro studies. Reversibility of the split-luciferase reporter binding demonstrated convertible organization of the mammalian MSC, including interferon gamma (IFNγ)-stimulated glutamyl-prolyl-tRNA synthetase 1 (EPRS1) release, as well as the cooperation with the ribosome bridged by the tRNAs. The cell-based analysis provided an improved understanding of the flexible framework of the mammalian MSC in physiological conditions.
|Number of pages||13|
|Publication status||Published - 2020 Aug 1|
Bibliographical noteFunding Information:
This work was supported by the Global Frontier Project grant (NRF‐M3A6A4‐2010‐0029785) of National Research Foundation funded by the Ministry of Science and ICT (MSIT) of Korea.
© 2020 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology
All Science Journal Classification (ASJC) codes
- Molecular Biology