title: Saccharomyces cerevisiae possesses a stress-inducible glycyl-tRNA synthetase gene.
abstract: Aminoacyl-tRNA synthetases are a large family of housekeeping enzymes that are pivotal in protein translation and other vital cellular processes. Saccharomyces cerevisiae possesses two distinct nuclear glycyl-tRNA synthetase (GlyRS) genes, GRS1 and GRS2. GRS1 encodes both cytoplasmic and mitochondrial activities, while GRS2 is essentially silent and dispensable under normal conditions. We herein present evidence that expression of GRS2 was drastically induced upon heat shock, ethanol or hydrogen peroxide addition, and high pH, while expression of GRS1 was somewhat repressed under those conditions. In addition, GlyRS2 (the enzyme encoded by GRS2) had a higher protein stability and a lower K(M) value for yeast tRNA(Gly) under heat shock conditions than under normal conditions. Moreover, GRS2 rescued the growth defect of a GRS1 knockout strain when highly expressed by a strong promoter at 37 °C, but not at the optimal temperature of 30 °C. These results suggest that GRS2 is actually an inducible gene that may function to rescue the activity of GRS1 under stress conditions.
authors.affiliation: Department of Life Sciences, National Central University, Jung-li, Taiwan.
authors.forename: Shun-Jia
authors.initials: SJ
authors.lastname: Chen
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Wu
authors.forename: Hsiao-Yun
authors.initials: HY
authors.lastname: Huang
authors.forename: Chien-Chia
authors.initials: CC
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D004790:Enzyme Induction; D004795:Enzyme Stability; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D006032:Glycine-tRNA Ligase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D015003:Yeasts / Q000201:enzymology / Q000235:genetics
chemical_list: D029701:Saccharomyces cerevisiae Proteins; C478769:GRS1 protein, S cerevisiae; D006032:Glycine-tRNA Ligase