High impact information on Kars

• Expression of the two lysyl-tRNA synthetase-green fluorescent protein gene fusions in a human cell line confirmed that the cytoplasmic form was targeted to the cytoplasm and the mitochondrial form to mitochondria [1].
• The genomic lysyl-tRNA synthetase gene consisted of 15 exons [1].
• The human lysyl-tRNA synthetase gene encodes both the cytoplasmic and mitochondrial enzymes by means of an unusual alternative splicing of the primary transcript [1].
• Free lysyl-tRNA synthetase dissociated from the synthetase complex is about 6-fold more active than the complex in AppppA synthesis, while their apparent Michaelis constants for ATP and lysine are similar [2].
• Bisubstrate kinetics and end product and dead end inhibition studies were performed on lysyl-tRNA synthetase isolated from rat liver [3].

Biological context of Kars

• Ap4A acts as a competitive inhibitor for ATP in the aminoacylation reaction of lysyl-tRNA synthetase with a KI of 2.5 microM [4].
• A chimeric enzyme, made of the amino-terminal moiety of rat liver aspartyl-tRNA synthetase fused to the catalytic domain of yeast lysyl-tRNA synthetase, has been expressed in Lys-101 cells, a CHO cell line with a temperature-sensitive lysyl-tRNA synthetase [5].

Anatomical context of Kars

• On the contrary we show that less than 2% of the total histidyl-tRNA and lysyl-tRNA synthetase activities are associated with purified rat liver nuclei or the hepatocyte intermediate filament-nuclear fraction [6].

Associations of Kars with chemical compounds

• Free lysyl-tRNA synthetase as dissociated from the synthetase complex, is evidently a dimeric enzyme with a subunit molecular weight of 66,000 +/- 3,000, as determined by gel electrophoresis, sucrose gradient centrifugation and gel filtration [7].
• In the presence of polyethylene glycol, in which the high Mr multi-enzyme complex containing lysyl-tRNA synthetase is insoluble, 65% of the lysyl-tRNA synthetase and only 15% of histidyl-tRNA synthetase activities remained associated with the cytoskeletal framework [6].
• Characterization of a homogeneous complex of arginyl- and lysyl-tRNA synthetase: zinc and adenosine 5'-phosphate dependent synthesis of diadenosine 5',5'''-P1,P4-tetraphosphate [4].
• The lysyl-tRNA synthetase (E.C. 6.1.1.6) was selectively dissociated by hydrophobic interaction chromatography on 1,6 diaminohexyl agarose followed by hydroxylapatite chromatography and DEAE chromatography [8].
• Lysyl-tRNA synthetase isolated from rat liver cleaves glycosidic bond of 5-Fluorouridine and 5-Fluoro-2'-deoxyuridine to generate 5-Fluorouracil [9].

Other interactions of Kars

• It is shown that irrespective of the addition or not of several proteinase inhibitors, lysyl-tRNA synthetase was present exclusively as a high-Mr entity, while arginyl-tRNA synthetase occurred as high- and low-Mr forms, in the constant proportions of 2:1, respectively [10].

References