Changes in macromolecular synthesis associated with the induction of glutamine synthetase in embryonic retina.
The hydrocortisone-mediated induction of glutamine synthetase in the neural retina of chicken embryo in vitro is correlated with enhanced incorporation into protein of [(14)C]aspartic acid, an amino acid abundant in this enzyme. In the induced retina labeled with [(14)C]aspartic acid, a peak of radioactivity was detected in the region of the polysomal profile corresponding to polysomes comprising 12-14 ribosomes. In retinas labeled with [(3)H]uridine, an increased amount of radioactivity was also detected in the same polysomal region of the hydrocortisone-induced retina. If we assume a monocistronic messenger RNA for retinal glutamine synthetase, this region corresponds to the estimated size of the polysomes necessary for the translation of this enzyme. The evidence presented demonstrates a correlation between these changes in incorporation and the induction of glutamine synthetase.
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D001345:Autoradiography; D002247:Carbon Isotopes; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D003561:Cytarabine / Q000494:pharmacology; D004790:Enzyme Induction; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology*; D046911:Macromolecular Substances / Q000096:biosynthesis; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis; D012160:Retina / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D012270:Ribosomes / Q000032:analysis; D014316:Tritium; D014529:Uridine / Q000378:metabolism
D002247:Carbon Isotopes; D046911:Macromolecular Substances; D011506:Proteins; D003561:Cytarabine; D014316:Tritium; D001224:Aspartic Acid; D005974:Glutamate-Ammonia Ligase; D014529:Uridine; D006854:Hydrocortisone