Open AccessRegulation of ex-translational activities is the primary function of the multi-tRNA synthetase complex
Author(s) -
Haissi Cui,
Mridu Kapur,
Jolene K. Diedrich,
John R. Yates,
Susan L. Ackerman,
Paul Schimmel
Publication year - 2020
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/gkaa1183
Subject(s) - biology , transfer rna , ribosome , translation (biology) , protein biosynthesis , aminoacyl trna synthetase , biochemistry , translational regulation , messenger rna , glutamine synthetase , amino acyl trna synthetases , amino acid , glutamine , microbiology and biotechnology , rna , gene
During mRNA translation, tRNAs are charged by aminoacyl-tRNA synthetases and subsequently used by ribosomes. A multi-enzyme aminoacyl-tRNA synthetase complex (MSC) has been proposed to increase protein synthesis efficiency by passing charged tRNAs to ribosomes. An alternative function is that the MSC repurposes specific synthetases that are released from the MSC upon cues for functions independent of translation. To explore this, we generated mammalian cells in which arginyl-tRNA synthetase and/or glutaminyl-tRNA synthetase were absent from the MSC. Protein synthesis, under a variety of stress conditions, was unchanged. Most strikingly, levels of charged tRNAArg and tRNAGln remained unchanged and no ribosome pausing was observed at codons for arginine and glutamine. Thus, increasing or regulating protein synthesis efficiency is not dependent on arginyl-tRNA synthetase and glutaminyl-tRNA synthetase in the MSC. Alternatively, and consistent with previously reported ex-translational roles requiring changes in synthetase cellular localizations, our manipulations of the MSC visibly changed localization.