Identification of three protein kinases which phosphorylate threonyl-tRNA synthetase from rat liver.
Threonyl-tRNA synthetase is phosphorylated in Chinese hamster ovary cells labeled with 32Pi [(1984) J. Biol. Chem. 259, 11160-11161]. Phosphorylation of the purified synthetase from rat liver has been examined with five different protein kinases. Three of the enzymes phosphorylate the synthetase, protease activated kinase I, the cAMP-dependent protein kinase, and the Ca2+, phospholipid-dependent protein kinase. Phosphorylation occurs exclusively on seryl residues. Two-dimensional phosphopeptide maps of tryptic digests of the phosphorylated synthetase are distinct with each protein kinase. These data suggest that multiple phosphorylation of the synthetase may occur in vivo.
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D047388:Casein Kinases; D000242:Cyclic AMP / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D010743:Phospholipids / Q000494:pharmacology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000378:metabolism; D013914:Threonine-tRNA Ligase / Q000378:metabolism*
D010743:Phospholipids; D012694:Serine; D000242:Cyclic AMP; D011494:Protein Kinases; C036447:protease activated kinase I; D047388:Casein Kinases; D000604:Amino Acyl-tRNA Synthetases; D013914:Threonine-tRNA Ligase; D002118:Calcium