Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The addition of phorbol esters to U937 leukemic cells stimulates the phosphorylation of c-Jun on serines 63 and 73. To isolate the protein kinase which stimulates this phosphorylation, we have used heparin-Sepharose chromatography followed by affinity chromatography over glutathione-Sepharose beads bound with a fusion protein of glutathione S-transferase and amino acids 5-89 of c-Jun (GST-c-Jun). Using this procedure we purify a 67-kDa protein which is capable of phosphorylating GST-c-Jun as well as the complete c-Jun protein. By making mutations in serines 63 and 73 and then creating a fusion protein with GST (GST-c-Jun mut), we demonstrate that this protein kinase specifically phosphorylates these sites in the c-Jun amino terminus. Treatment of purified c-Jun amino-terminal protein kinase (cJAT-PK) with phosphatase 2A inhibits its ability to phosphorylate GST-c-Jun. This inactivated enzyme can be reactivated by phosphorylation with protein kinase C (PKC), although PKC is not capable of phosphorylating the GST-c-Jun substrate. Because v-Jun cannot be phosphorylated in vivo, we compared the ability of cJAT-PK to bind to GST-v-Jun or GST-c-Jun mut. The cJAT-PK bound 50-fold better to GST-c-Jun mut than GST-v-Jun suggesting that the delta domain which is missing in v-Jun plays a role in binding the cJAT-PK. These results suggest that there is a protein kinase cascade mediated by protein phosphatases and PKC which regulates c-Jun phosphorylation.
...
PMID:Affinity-purified c-Jun amino-terminal protein kinase requires serine/threonine phosphorylation for activity. 132 19

Mitogen-activated protein (MAP) kinases are 42- and 44-kD serine-threonine protein kinases that are activated by tyrosine and threonine phosphorylation in cells stimulated with mitogens and growth factors. MAP kinase and the protein kinase that activates it (MAP kinase kinase) were constitutively activated in NIH 3T3 cells infected with viruses containing either of two oncogenic forms (p35EC12, p3722W) of the c-Raf-1 protein kinase. The v-Raf proteins purified from cells infected with EC12 or 22W viruses activated MAP kinase kinase from skeletal muscle in vitro. Furthermore, a bacterially expressed v-Raf fusion protein (glutathione S-transferase-p3722W) also activated MAP kinase kinase in vitro. These findings suggest that one function of c-Raf-1 in mitogenic signaling is to phosphorylate and activate MAP kinase kinase.
...
PMID:Activation of mitogen-activated protein kinase kinase by v-Raf in NIH 3T3 cells and in vitro. 138 11

The UL13 open reading frame of herpes simplex virus type 1 (HSV-1) has been expressed in insect cells by a recombinant baculovirus and in Escherichia coli. In the latter case, the UL13 gene was fused to the gene for glutathione S-transferase (GST) to allow high-level expression of an 80-kDa GST-UL13 fusion protein. Antibody raised against the fusion protein reacted specifically with the 55-kDa UL13 gene product expressed by the recombinant baculovirus. This antibody also recognized a late phosphoprotein in HSV-1-infected cell lysates and a component of purified HSV-1 virions, both with the same electrophoretic mobility as the baculovirus-expressed protein. The virion component was efficiently phosphorylated in vitro by a virion-associated protein kinase. Using the same antibody, the probable homolog of the UL13 gene product was identified in HSV-2-infected cells and purified virions.
...
PMID:Herpes simplex virus type 1 gene UL13 encodes a phosphoprotein that is a component of the virion. 132 2

In the yeast Saccharomyces cerevisiae genetic and biochemical evidence indicates that the product of the CDC25 gene activates the RAS/adenylyl cyclase/protein kinase A pathway by acting as a guanine nucleotide protein. Here we report the isolation of a mouse brain cDNA homologous to CDC25. The mouse cDNA, called CDC25Mm, complements specifically point mutations and deletion/disruptions of the CDC25 gene. In addition, it restores the cAMP levels and CDC25-dependent glucose-induced cAMP signalling in a yeast strain bearing a disruption of the CDC25 gene. The CDC25Mm-encoded protein is 34% identical with the catalytic carboxy terminal part of the CDC25 protein and shares significant homology with other proteins belonging to the same family. The protein encoded by CDC25Mm, prepared as a glutathione S-transferase fusion in Escherichia coli cells, activates adenylyl cyclase in yeast membranes in a RAS2-dependent manner. Northern blot analysis of mouse brain poly(A)+ RNA reveals two major transcripts of approximately 1700 and 5200 nucleotides. Transcripts were found also in mouse heart and at a lower level in liver and spleen.
...
PMID:Cloning by functional complementation of a mouse cDNA encoding a homologue of CDC25, a Saccharomyces cerevisiae RAS activator. 137 46

The Xenopus cdk2 gene encodes a 32-kDa protein kinase with sequence similarity to the 34-kDa product of the cdc2 gene. Previous studies have shown that the kinase activity of the protein product of the cdk2 gene oscillates in the Xenopus embryonic cell cycle with a high in M-phase and a low in interphase. In the present study cdk2 was found not to be associated with any newly synthesized proteins during the cell cycle, but the enzyme did undergo periodic changes in phosphorylation. Upon exit from metaphase, cdk2 became increasingly phosphorylated on both tyrosine and serine residues, and labeling on these residues increased progressively until entry into mitosis, when tyrosine residues were markedly dephosphorylated. Phosphopeptide mapping of cdk2 demonstrated the major sites of phosphorylation were in a phosphopeptide with a pI of 3.7 that contained both phosphoserine and phosphotyrosine. This phosphopeptide accumulated in egg extracts blocked in S-phase with aphidicolin and was not evident in cdc2 immunoprecipitated under the same conditions. Under the same conditions cdc2 was phosphorylated primarily on a phosphopeptide containing both phosphothreonine and phosphotyrosine residues, most likely threonine 14 and tyrosine 15. Affinity-purified human GST-cdc25 was able to dephosphorylate and activate cdk2 isolated from interphase cells. Phosphopeptide mapping demonstrated that the phosphate was specifically removed from the same phosphopeptide identified as the major in vivo site of phosphorylation. These results demonstrate that cdk2 is regulated in the cell cycle by phosphorylation and dephosphorylation on both serine and tyrosine residues. Moreover, the increased phosphorylation of cdk2 in aphidicolin-blocked extracts and the ability of cdc25 to mediate cdk2 dephosphorylation in vitro suggest the possibility that cdk2 is part of the mechanism ensuring mitosis is not initiated until completion of DNA replication. It also implies cdc25 may have other functions in addition to the regulation of cdc2 kinase activity.
...
PMID:Cdc25 regulates the phosphorylation and activity of the Xenopus cdk2 protein kinase complex. 151 36

The regulation of the Erk (extracellular-signal-regulated kinase) gene-encoded protein kinase activity by reversible phosphorylation has been reported to involve either an activator of autophosphorylation or an upstream protein kinase. In this communication we describe assays utilizing the Erk-1 protein fused to glutathione S-transferase that permit the identification of protein kinase(s) that phosphorylate and activate the myelin basic protein kinase activity encoded by the Erk-1 gene. A phorbol ester-stimulated protein kinase activity was identified that phosphorylated a kinase-negative Erk-1 gene product on tyrosine and threonine. The protein kinase phosphorylated and activated wild-type protein expressed in bacteria from 20- to 50-fold. The activation of the Erk-1-encoded myelin basic protein kinase required ATP and correlated directly with the degree of phosphorylation on the same amino acid residues previously shown to be phosphorylated in vivo. Conversion of the tyrosine site of phosphorylation to phenylalanine yielded an Erk-1 gene product that could not be activated. Similar results were obtained when the threonine site was mutated to valine. It is likely that the phorbol ester-stimulated protein-tyrosine/threonine kinase(s) is an up-stream target for multiple extracellular signals.
...
PMID:Phorbol ester stimulates a protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product. 151 47

The nucleotide sequence of the vaccinia virus open reading frame B1 predicts a polypeptide with significant sequence similarity to the catalytic domain of known protein kinases. To determine whether the B1R polypeptide is a protein kinase, we have expressed it in bacteria as a fusion with glutathione S-transferase. Affinity-purified preparations of the fusion protein were found to undergo autophosphorylation and also phosphorylated the exogenous substrates casein and histone H1. Mutation of lysine 41 to glutamine within the conserved kinase catalytic domain II abrogated protein kinase activity on all three protein substrates, supporting the notion that the protein kinase activity is inherent to the B1R polypeptide. Casein and histone H1 were phosphorylated on serine and threonine residues. The B1R fusion protein was phosphorylated on a threonine residue(s) by an apparently intramolecular mechanism. The autophosphorylation reaction resulted in phosphorylation of the glutathione S-transferase portion of the fusion and not the protein kinase domain. The protein kinase activity of B1R was specific for ATP as the phosphate donor; GTP was not utilized to a detectable extent. Immunoblotting experiments with anti-B1R antiserum showed that the protein kinase is located in the virion particle. Chromatography of virion extracts resulted in separation of the B1R protein kinase from the bulk of the total protein kinase activity, indicating that multiple protein kinases are present in the virion particle and that B1R is distinct from the previously described vaccinia virus-associated protein kinase.
...
PMID:The vaccinia virus B1R gene product is a serine/threonine protein kinase. 156 May 22

c-Jun and its oncogenic counterpart v-Jun are completely conserved within the region from Ser-63 to Ser-73; these serines are sites for phorbol ester-inducible c-Jun phosphorylation. Using a U937 human leukemic cell line stably expressing v-Jun, we have demonstrated that phorbol esters stimulate the in vivo phosphorylation of c-Jun but not v-Jun. We developed an in vitro protein kinase assay to characterize the c-Jun protein kinase and to examine the determinants underlying this differential phosphorylation. Fusion proteins between glutathione S-transferase and the N terminus of c-Jun, v-Jun, or several c-Jun mutants were used as substrates. A c-Jun kinase activity was affinity-purified 5000-fold by using glutathione S-transferase-c-Jun-glutathione-Sepharose beads and was found to phosphorylate the N terminus of c-Jun but not v-Jun or c-Jun containing a 27-amino acid N-terminal deletion found in v-Jun. These effects were also observed in vivo as phorbol 12-myristate 13-acetate did not induce the phosphorylation of v-Jun or the c-Jun deletion mutant in U937 cell lines stably expressing these proteins. These findings indicate that the delta domain of c-Jun (amino acids 34-60), which is deleted in v-Jun, plays a critical role in regulating N-terminal c-Jun phosphorylation.
...
PMID:Phorbol esters stimulate the phosphorylation of c-Jun but not v-Jun: regulation by the N-terminal delta domain. 160 42

Activation of purified glutathione transferase (CE 2.5.1.18) from the rabbit liver by cAMP-dependent protein kinase (protein kinase A) and activation of glutathione transferase from the rat liver and heart by cAMP preparations have been studied. A comparison of glutathione transferase activation on different substrates and the results of the inhibitor analysis of the activation phenomenon have shown that the second (mu) family of glutathione transferase isoenzymes (subunits, 3, 4, 6) is the most probable object of regulation. The first (alpha) family (subunits 1 and 2) and isoenzyme 5-5 are not probably regulated.
...
PMID:[Regulation of various isoenzymes of glutathione transferases of protein kinase A and cAMP]. 165 3

Diacylglycerol (DG) and its analogue phorbol 12-myristate 13-acetate (PMA) activate the ubiquitous phospholipid/Ca2(+)-dependent protein kinase, protein kinase C (PKC), and cause it to become tightly associated with membranes. DG is produced transiently as it is rapidly metabolized by DG kinase (DGK) to phosphatidic acid. Phorbol esters such as PMA are not metabolized and induced a prolonged membrane association of PKC. Until recently, PKC was the only known phorbol ester receptor. We have shown that a novel brain-specific cDNA, neuronal chimaerin (NC), expressed in Escherichia coli, binds phorbol ester with high affinity, stereospecificity and a phospholipid requirement [Ahmed, Kozma, Monfries, Hall, Lim, Smith & Lim (1990) Biochem. J. 272, 767-773]. The proteins NC, PKC and DGK possess a cysteine-rich domain with the motif HX11/12CX2CXnCX2CX4HX2CX6/7C (where n varies between 12 and 14). The partial motif, CX2CX13CX2C, is present in a number of transcription factors including the steroid hormone receptors and the yeast protein, GAL4, in which zinc plays a structural role of co-ordinating cysteine residues and is essential for DNA binding (protein-nucleic acid interactions). The cysteine-rich domain of NC and PKC is required for phospholipid-dependent phorbol is required for phospholipid-dependent phorbol ester binding, suggesting an involvement of this domain in protein-lipid interactions. We have expressed recombinant NC, PKC and DGK glutathione S-transferase and TrpE fusion proteins in E. coli to investigate the relationship between the cysteine-rich motif, HX11/12CX2CX10-14CX2CX4HX2CX6/7C, zinc and phorbol ester binding. The cysteine-rich domain of NC, PKC and DGK bound 65Zn2+ but only NC and PKC bound [3H]phorbol 12,13-dibutyrate. When NC and PKC were subjected to treatments known to remove metal ions from GAL4 and the human glucocorticoid receptor, phorbol ester binding was inhibited. These data provide evidence for the role of a zinc-dependent structure in phorbol ester binding.
...
PMID:The cysteine-rich domain of human proteins, neuronal chimaerin, protein kinase C and diacylglycerol kinase binds zinc. Evidence for the involvement of a zinc-dependent structure in phorbol ester binding. 166 Feb 66


1 2 3 4 5 6 7 8 9 10 Next >>

---