EC Number   |
Posttranslational Modification  |
Reference |
|---|
    6.3.4.2 | phosphoprotein |
CTP synthetase is phosphorylated by protein kinase C which leads to 95fold higher activity of CTP synthetase 1. Phosphopeptide mapping and phosphoamino acid analyses shows that CTP synthetase 1 is phosphorylated on multiple serine and threonine residues. It is indicated that protein kinase C phosphorylation at Ser462 stimulates human CTP synthetase 1 activity, whereas phosphorylation at Thr455 inhibits activity |
674816 |
| 6.3.4.2 | phosphoprotein |
it is shown that Ser-574 and Ser-575 are phosphorylated residues. Mutation of Ser-571 demonstrates that Ser-571 is the major site phosphorylated by glycogen synthase kinase 3 in intact human embryonic kidney 293 cells by glycogen synthase kinase 3 in vitro. Mutation of Ser-575 prevents phosphorylation of Ser-571, suggesting phosphorylation of Ser-575 is necessary for priming the glycogen synthase kinase 3 phosphorylation of Ser-571 |
674862 |
| 6.3.4.2 | phosphoprotein |
Low serum treatment increases CTPS2 phosphorylation. Ser568 and Ser571 are two major phosphorylation sites, and Ser568 is phosphorylated by casein kinase 1 both in vitro and in vivo. Mutation of S568A but not S571A significantly increases CTPS2 activity. The S568A mutation has a greater effect on the glutamine than ammonia-dependent activity |
715549 |
| 6.3.4.2 | phosphoprotein |
phosphorylation of CTP synthetase by protein kinase A results in the stimulation of CTP synthetase activity. The mechanism of stimulation involves an increase in Vmax of the reaction and an increase of the enzyme affinity for ATP |
648994 |
| 6.3.4.2 | phosphoprotein |
phosphorylation of the purified native CTP synthetase with protein kinase A and protein kinase C facilitates the nucleotide-dependent tetramerization. Dephosphorylation of native CTP-desynthetase with alkaline phosphatase prevents the nucleotide-dependent tetramerization of the enzyme |
648975 |
| 6.3.4.2 | phosphoprotein |
stimulation/inhibition of protein kinase A and protein kinase C does not alter the phosphorylation of endogenous human CTPS1 in human embryonic kidney 293 cells. Low serum conditions increased phosphorylation of endogenous CTPS1 and phosphorylation is inhibited by the glycogen synthase kinase 3 (GSK3) inhibitor indirubin-3-monoxime and GSK3beta short interfering RNAs, demonstrating the involvement of glycogen synthase kinase 3 in phosphorylation of endogenous human CTPS1 |
674862 |
| 6.3.4.2 | phosphoprotein |
the CTPS1-encoded enzyme is phosphorylated by protein kinases A and C at Thr455, and these phosphorylations stimulate CTP synthetase activity and increase cellular CTP levels and the utilization of the Kennedy pathway |
694934 |
| 6.3.4.2 | phosphoprotein |
the enzyme is phosphorylated and stimulated by protein kinase C. Phosphorylation of CTP synthetase on Ser36, Ser330, Ser354, and Ser454 regulates the levels of CTP and phosphatidylcholine synthesis |
648973 |
| 6.3.4.2 | phosphoprotein |
the URA7-encoded enzyme is phosphorylated at Ser424 by protein kinases A and C, and these phosphorylations stimulate CTP synthetase activity and increase cellular CTP levels and the utilization of the Kennedy pathway |
694934 |
| 6.3.4.2 | ubiquitination |
reversible ubiquitination regulates the dynamic assembly of the filamentous structures of Drosophila CTPsyn. The proto-oncogene Cbl, an E3 ubiquitin ligase, controls CTPsyn filament formation in endocycles. The E3 ligase activity of Cbl is required for CTPsyn filament formation, and Cbl does not affect the protein levels of CTPsyn. In the absence of Cbl or with knockdown of CTPsyn, the progression of the endocycle-associated S phase is impaired. Overexpression of wild-type, but not enzymatically inactive CTPsyn, rescues the endocycle defect in Cbl mutant cells |
745038 |
