Tryptophanyl-tRNA synthetase is a major soluble protein species in bovine pancreas

• Published in: Biochimica et biophysica acta Vol. 882; no. 2; pp. 192 - 199
• Main Authors: Sallafranque, Marie-Line, Garret, Maurice, Benedetto, Jean-Pierre, Fournier, Michel, Labouesse, Bernard, Bonnet, Jacques
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 19.06.1986
• Subjects: Amino Acyl-tRNA Synthetases; Amino Acyl-tRNA Synthetases - metabolism; Aminoacyl-tRNA synthetase; animal proteins; Animals; Bovine pancreas; Cattle; Cytosol; Cytosol - enzymology; Electrophoresis, Polyacrylamide Gel; enzyme activity; enzymes; enzymology; Immunoelectrophoresis; Immunosorbent Techniques; metabolism; Methionine-tRNA Ligase; Methionine-tRNA Ligase - metabolism; pancreas; Pancreas - enzymology; RNA, Transfer; RNA, Transfer - metabolism; solubility; Tissue Distribution; Tryptophan-tRNA Ligase; Tryptophan-tRNA Ligase - metabolism; Tryptophanyl-tRNA synthetase; Tryptophanyl-tRNA synthetase; Bovine pancreas; Tissue distribution; Aminoacyl-tRNA synthetase
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(86)90155-8

Besides their central role in protein synthesis, aminoacyl-tRNA synthetases have been found or thought to be involved in other processes. We present here a study showing that tryptophanyl-tRNA synthetase has a surprising tissular distribution. Indeed, immunochemical determinations showed that in several bovine organs such as liver, kidney and heart, tyrptophanyl-tRNA synthetase constitutes, as expected, about 0.02% of soluble proteins. In spleen, brain cortex, stomach, cerebellum or duodenum, this amount is about 10-times higher, and in pancreas it is 100-fold. There is no correlation between these amounts and the RNA content of the organs. Moreover, the concentration of another aminoacyl-tRNA synthetase (methionyl-tRNA synthetase) is higher in liver than in pancreas, while the amount of tRNA Trp is not higher in pancreas than in liver as compared to other tRNAs. Among several interpretations, it is possible that tryptophanyl-tRNA synthetase is involved in a function other than tRNA aminoacylation. This uuknown function would be specific to the differentiated organs, since fetal cerebellum and fetal pancreas contain the same amount of tryptophanyl-tRNA synthetase as adult liver.