title: Protein synthesis and loss of viability in rye embryos. The lability of transferase enzymes during senscence.
abstract: 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.
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D000375:Aging; D000596:Amino Acids / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases; D001665:Binding Sites; D002250:Carbon Radioisotopes; D002474:Cell-Free System; D002523:Edible Grain / Q000201:enzymology*; D005033:Ethylmaleimide / Q000494:pharmacology; D006160:Guanosine Triphosphate; D007700:Kinetics; D010441:Peptide Chain Elongation, Translational; D010649:Phenylalanine; D010940:Plant Proteins / Q000096:biosynthesis*; D011188:Potassium / Q000494:pharmacology; D012343:RNA, Transfer; D012270:Ribosomes / Q000201:enzymology; D012639:Seeds / Q000201:enzymology* / Q000254:growth & development
chemical_list: D000596:Amino Acids; D002250:Carbon Radioisotopes; D010940:Plant Proteins; D010649:Phenylalanine; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D000217:Acyltransferases; D000604:Amino Acyl-tRNA Synthetases; D005033:Ethylmaleimide; D011188:Potassium