scholarly journals Protein synthesis and loss of viability in rye embryos. The lability of transferase enzymes during senescence

1973 ◽  
Vol 135 (3) ◽  
pp. 405-410 ◽  
Author(s):  
B. E. Roberts ◽  
D. J. Osborne

Poor germination and eventual loss of viability of rye grains on storage reflects a decreasing ability of embryos to synthesize protein in vivo. Cell-free protein-synthesizing systems from low viability embryo stocks exhibit lesions in the soluble components of the post-ribosomal supernatant fractions. tRNA and aminoacyl-tRNA synthetases are not impaired. The activity of enzymes concerned with transfer of phenylalanyl-tRNA from the aminoacyl to the peptidyl site on the ribosome is slightly decreased. The transfer enzymes (transferase I) involved in the binding of phenylalanyl-tRNA to the aminoacyl site show a loss of activity that closely reflects the loss of viability and the decline of protein synthesis of the embryo in vivo. The inactivation of labile transferase I components may be a major factor leading to senescence and loss of viability in rye grains.

1972 ◽  
Vol 18 (12) ◽  
pp. 1837-1843 ◽  
Author(s):  
S. R. Bobier ◽  
G. D. Ferroni ◽  
W. E. Inniss

Protein synthesis by whole cells of two psychrophilic bacteria, Bacillus psychrophilus and Bacillus insolitus, directly corresponded to the growth of these organisms at 5, 20 and 30C, with a smaller total amount of growth and protein synthesis occurring at 30C than at 20C. When the effect of temperature on protein synthesis was examined using extracts, the capability to carry out poly U directed incorporation of 14C-L-phenylalanine into protein was inhibited by 30C as compared to 5C. The temperature sensitivity of the cell-free protein synthesizing systems was not due to the presence of heat-sensitive aminoacyl-tRNA synthetases. Investigation of the effect of separately heating at 30C washed ribosome (W-RIB) and supernatant (IS-100) fractions prepared from these microorganisms, followed by recombination and reaction at 15C, showed that the temperature sensitivity of the protein synthesis resided in the ribosomal fraction of the cells


2021 ◽  
Vol 7 (8) ◽  
pp. 593
Author(s):  
Jingjing Wang ◽  
Alexander Berestetskiy ◽  
Qiongbo Hu

Destruxin A (DA), a hexa-cyclodepsipeptidic mycotoxin produced by the entomopathogenic fungus Metarhizium anisopliae, exhibits insecticidal activities in a wide range of pests and is known as an innate immunity inhibitor. However, its mechanism of action requires further investigation. In this research, the interactions of DA with the six aminoacyl tRNA synthetases (ARSs) of Bombyx mori, BmAlaRS, BmCysRS, BmMetRS, BmValRS, BmIleRS, and BmGluProRS, were analyzed. The six ARSs were expressed and purified. The BLI (biolayer interferometry) results indicated that DA binds these ARSs with the affinity indices (KD) of 10−4 to 10−5 M. The molecular docking suggested a similar interaction mode of DA with ARSs, whereby DA settled into a pocket through hydrogen bonds with Asn, Arg, His, Lys, and Tyr of ARSs. Furthermore, DA treatments decreased the contents of soluble protein and free amino acids in Bm12 cells, which suggested that DA impedes protein synthesis. Lastly, the ARSs in Bm12 cells were all downregulated by DA stress. This study sheds light on exploring and answering the molecular target of DA against target insects.


1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.


1986 ◽  
Vol 236 (1) ◽  
pp. 163-169 ◽  
Author(s):  
U Del Monte ◽  
S Capaccioli ◽  
G Neri Cini ◽  
R Perego ◽  
R Caldini ◽  
...  

The tRNA content and aminoacyl-tRNA synthetases of regenerating liver in the phase of rapid growth were compared with those of livers from both intact and sham-operated rats. At 48 h after hepatectomy, the amount of active tRNA (called ‘total acceptor capacity’) is significantly higher in regenerating liver than in control livers, owing to a general, possibly not uniform, increase in the various tRNA families, which suggests that it may contribute to the increased protein synthesis and to decreased protein degradation as well. The activities of most, but not of all, aminoacyl-tRNA synthetases in cell sap of regenerating liver tend to be greater than normal. Increased activity of histidyl-tRNA synthetase fits in with the possibility that the mechanisms that control the rate of protein degradation through aminoacylation of tRNAHis in cultured cells [Scornik (1983) J. Biol. Chem. 258, 882-886] also operate in the liver and play a role in regeneration. Sedimentation analysis of cell sap in sucrose density gradients shows a shift of prolyl-tRNA synthetase activity toward the high-Mr form in regenerating liver. This change might be related to the positive protein balance and to growth in vivo, since it is also observed in the anaplastic Yoshida ascites hepatoma AH 130.


Metabolism ◽  
1978 ◽  
Vol 27 (9) ◽  
pp. 1387-1390 ◽  
Author(s):  
Karl-Heinz Tragl ◽  
Helmut Kinast ◽  
Helmut Steininger ◽  
Georg Geyer

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Tammy J Bullwinkle ◽  
Noah M Reynolds ◽  
Medha Raina ◽  
Adil Moghal ◽  
Eleftheria Matsa ◽  
...  

Aminoacyl-tRNA synthetases use a variety of mechanisms to ensure fidelity of the genetic code and ultimately select the correct amino acids to be used in protein synthesis. The physiological necessity of these quality control mechanisms in different environments remains unclear, as the cost vs benefit of accurate protein synthesis is difficult to predict. We show that in Escherichia coli, a non-coded amino acid produced through oxidative damage is a significant threat to the accuracy of protein synthesis and must be cleared by phenylalanine-tRNA synthetase in order to prevent cellular toxicity caused by mis-synthesized proteins. These findings demonstrate how stress can lead to the accumulation of non-canonical amino acids that must be excluded from the proteome in order to maintain cellular viability.


1983 ◽  
Vol 38 (9-10) ◽  
pp. 881-882 ◽  
Author(s):  
Hans-Joachim Gabius ◽  
Sigrun Gabius ◽  
Gerhart Graupner ◽  
Friedrich Cramer ◽  
Sabine Rehm

The specific activities of 17 aminoacyl-tRNA synthetases in liver, lung, heart, spleen, kidney and small intestine of old female normal and leukemic (reticulum -cell sarcoma, type A) mice have been monitored. No difference appears for lung, heart and kidney; small increases with varying particular changes for liver and marked increases in spleen and small intestine of the tumor bearing mice have been found, following a similar pattern. This finding suggests a coordinated adaptation to modulation of the requirements of protein synthesis imposed by histiocytic sarcoma.


2000 ◽  
Vol 149 (3) ◽  
pp. 567-574 ◽  
Author(s):  
Young-Gyu Ko ◽  
Young-Sun Kang ◽  
Eun-Kyoung Kim ◽  
Sang Gyu Park ◽  
Sunghoon Kim

Human aminoacyl–tRNA synthetases (ARSs) are normally located in cytoplasm and are involved in protein synthesis. In the present work, we found that human methionyl–tRNA synthetase (MRS) was translocated to nucleolus in proliferative cells, but disappeared in quiescent cells. The nucleolar localization of MRS was triggered by various growth factors such as insulin, PDGF, and EGF. The presence of MRS in nucleoli depended on the integrity of RNA and the activity of RNA polymerase I in the nucleolus. The ribosomal RNA synthesis was specifically decreased by the treatment of anti-MRS antibody as determined by nuclear run-on assay and immunostaining with anti-Br antibody after incorporating Br-UTP into nascent RNA. Thus, human MRS plays a role in the biogenesis of rRNA in nucleoli, while it is catalytically involved in protein synthesis in cytoplasm.


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