The role of cyclic 3',5'-AMP in the regulation of aminoacyl-tRNA synthetase activities in mouse uterus and liver following 17beta-oestradiol treatment. Activation of a phosphoaminoacyl-tRNA synthetase phosphatase by phosphorylation with cyclic 3',5'-AMP dependent protein kinase.
The changes in the activities of 17 aminoacyl-tRNA synthetases induced by phosphorylation [1] were reversed by the action of cyclic AMP in preparations from both uterus and liver. Cyclic AMP also inhibited the phosphorylation of aminoacyl-tRNA synthetase protein by endogenous non-cyclic AMP-dependent protein kinase and [gamma-32P]ATP. The effect was not due to a stimulation of phosphoaminoacyl-tRNA synthetase phosphatase or to an influence of cyclic AMP on aminoacyl-tRNA synthetases. The activity of phosphoaminoacyl-tRNA synthetase phosphatase was increased by treatment with endogenous cyclic AMP-dependent protein kinase, ATP and cyclic AMP. Affinity chromatography of the 32P-labeled phosphorylated phosphosynthetase phosphatase protein followed by gel electrophoresis showed that the activated phosphatase was phosphorylated. In the uterus, the changes in 17 aminoacyl-tRNA synthetase activities observed 5 min after dibutyryl cyclic AMP administration to ovariectomized mice were similar to those observed after 17beta-oestradiol treatment, whereas in the liver the changes in these activities were the opposite to those found after treatment with 17beta-oestradiol. A mechanism for the regulation of the 17 aminoacyl-tRNA synthetase activities is proposed, which suggests that the synthetase activities inhibited (group I) or stimulated (group II) by phosphorylation with a non-cyclic AMP-dependent aminoacyl-tRNA synthetase kinase are reactivated (group I) or inhibited (group II), respectively, by the action of a cyclic AMP-dependent phosphatase kinase through the increased activity of phosphorylated phosphoaminoacyl-tRNA synthetase phosphatase.
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology*; D004789:Enzyme Activation; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D014599:Uterus / Q000187:drug effects / Q000201:enzymology*
D004958:Estradiol; D000242:Cyclic AMP; D011494:Protein Kinases; C022354:phosphoaminoacyl-tRNA synthetase phosphatase; D010749:Phosphoprotein Phosphatases; D000604:Amino Acyl-tRNA Synthetases