scholarly journals Myocardial aminoacyl-transfer-ribonucleic acid synthetase and aminoacyl-transferring enzyme activity

1972 ◽  
Vol 126 (2) ◽  
pp. 409-416 ◽  
Author(s):  
K. Gibson ◽  
P. Harris

The properties of cytoplasmic aminoacyl-tRNA synthetase and aminoacyl-transferring enzymes in the myocardium were examined and methods for the assay of the activity of these enzyme systems were developed. Aminoacyl-tRNA synthetase activity was measured from the rate of incorporation of 14C-labelled amino acid into aminoacyl-tRNA. Transferase activity was measured from the rate of incorporation of amino[14C]acyl-tRNA into protein in the presence of a standard preparation of hepatic ribosomes. Aminoacyl-tRNA synthetase activity is labile once the heart has been homogenized, whereas transferase activity is stable. The source of energy for synthetase activity is ATP; that for transferase is GTP. Transferase activity was inhibited by puromycin and stimulated by dithiothreitol, whereas synthetase activity was unaffected.

ChemBioChem ◽  
2014 ◽  
Vol 15 (12) ◽  
pp. 1755-1760 ◽  
Author(s):  
Moritz J. Schmidt ◽  
Annemarie Weber ◽  
Moritz Pott ◽  
Wolfram Welte ◽  
Daniel Summerer

2020 ◽  
Vol 117 (16) ◽  
pp. 8900-8911 ◽  
Author(s):  
Yeonjin Kim ◽  
Mark S. Sundrud ◽  
Changqian Zhou ◽  
Maja Edenius ◽  
Davide Zocco ◽  
...  

Signaling pathways that sense amino acid abundance are integral to tissue homeostasis and cellular defense. Our laboratory has previously shown that halofuginone (HF) inhibits the prolyl-tRNA synthetase catalytic activity of glutamyl-prolyl-tRNA synthetase (EPRS), thereby activating the amino acid response (AAR). We now show that HF treatment selectively inhibits inflammatory responses in diverse cell types and that these therapeutic benefits occur in cells that lack GCN2, the signature effector of the AAR. Depletion of arginine, histidine, or lysine from cultured fibroblast-like synoviocytes recapitulates key aspects of HF treatment, without utilizing GCN2 or mammalian target of rapamycin complex 1 pathway signaling. Like HF, the threonyl-tRNA synthetase inhibitor borrelidin suppresses the induction of tissue remodeling and inflammatory mediators in cytokine-stimulated fibroblast-like synoviocytes without GCN2, but both aminoacyl-tRNA synthetase (aaRS) inhibitors are sensitive to the removal of GCN1. GCN1, an upstream component of the AAR pathway, binds to ribosomes and is required for GCN2 activation. These observations indicate that aaRS inhibitors, like HF, can modulate inflammatory response without the AAR/GCN2 signaling cassette, and that GCN1 has a role that is distinct from its activation of GCN2. We propose that GCN1 participates in a previously unrecognized amino acid sensor pathway that branches from the canonical AAR.


1995 ◽  
Vol 309 (1) ◽  
pp. 321-324 ◽  
Author(s):  
C L Harris ◽  
C J Kolanko

The size distribution of aminoacyl-tRNA synthetase activity was investigated in cell extracts prepared from Saccharomyces cerevisiae. Bio-Gel A-5M chromatography of 105,000 g supernatants separated isoleucyl-tRNA synthetase activity into three peaks, with apparent molecular masses (Da) of about 100,000, 350,000 and 10(6) or greater. Similar results were obtained with synthetases specific for glutamic acid, serine and tyrosine. Sucrose-density-gradient centrifugation of yeast supernatants also provided evidence for the existence of synthetase complexes. These data provide the first evidence for the existence of a high-molecular-mass aminoacyl-tRNA synthetase complex in yeast, perhaps similar to those reported in higher eukaryotes.


2008 ◽  
Vol 378 (1) ◽  
pp. 90-92 ◽  
Author(s):  
Akimitsu Kugimiya ◽  
Miki Morii ◽  
Takashi Ohtsuki

2005 ◽  
Vol 280 (25) ◽  
pp. 23966-23977 ◽  
Author(s):  
Nathan T. Uter ◽  
Ita Gruic-Sovulj ◽  
John J. Perona

1977 ◽  
Vol 26 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Sylvia A. McCune ◽  
P. L. Yu ◽  
Walter E. Nance

To search for evidence of genetic variation among the aminoacyl-tRNA synthetases, a semi-automated assay procedure employing a Technicon Auto Analyzer was used to measure erythrocyte arginine-tRNA synthetase activity in samples obtained from normal human twins of various ages. Variation in enzyme activity within the older DZ twins was five times that of the MZ twins suggesting the existence of genetically determined variation in enzyme activity. Higher enzyme activity was observed in newborn DZ unlike-sexed twins than in like-sexed twins of either zygosity. Possible explanations for this observation are discussed.


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