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

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Query: EC:2.7.11.1 (protein kinase)
81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homogeneous rabbit liver phosphorylase phosphatase (Brandt, H., Capulong, Z. L., and Lee, E. Y. C. (1975) J. Biol. Chem. 250, 8038-8044) also dephosphorylates glycogen synthase b. During purification, phosphorylase phosphatase and glycogen synthase phosphatase co-purified with a constant ratio of activities. The two activities co-migrated on disc gel electrophoresis. Both substrates competed with each other for the phosphatase, and both phosphatase activities were inhibited by lysine ethyl ester. It is concluded that liver phosphorylase phosphatase and glycogen synthase phosphatase have a common identity and that coordinate regulation of the phosphatase-catalyzed activation of glycogen synthase and inactivation of phosphorylase occurs in vivo. This provides a parallel and opposing mechanism to that mediated by adenosine 3':5'-monophosphate-dependent protein kinase, which coordinately inactivates glycogen synthase and, via phosphorylase kinase, activates phosphorylase. Maximal glycogen synthase phosphatase activity was observed near neutrality. Mg2+ and glucose-6-P activated the glycogen synthase phosphatase reaction and this activation was pH-dependent. The Km for glycogen synthase b was 0.12 muM.
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PMID:Evidence for the coordinate control of activity of liver glycogen synthase and phosphorylase by a single protein phosphatase. 0 46

The tyrosine-3-monooxygenase activity [L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating); EC 1.14.16.2] of rat adrenal medulla is induced 20-24 hr after the injection of reserpine (16 mumol/kg intraperitoneally). This and other inducing stimuli increase the 3': 5'-cyclic AMP (cAMP) content in the medulla for longer than 60 min and activate the cAMP-dependent protein kinase (ATP: protein phosphotransferase; EC 2.7.1.37) for several hours. Corticotropin (ACTH), dopamine, and propranolol do not induce the monooxygenase, but elicit an increase in the cAMP content of the medulla which fails to activate protein kinase and lasts less than 1 hr. A high- and low-molecular-weight protein kinase are separated by gel filtration from the 20,000 X g pellet extract of adrenal medulla homogenate. The activity of the low-molecular-weight enzyme is expressed as its ability to phosphorylate histone. The protein kinase activity of the pellet is increased between 3 and 17 hr after reserpine injection. Our evidence indicates that this increase is due to a translocation from cytosol to subcellular structures of a kinase that utilizes lysine-rich histone as phosphate acceptor. The protein kinase activity that is extracted from a purified nuclear fraction prepared from the adrenal medulla of rats injected 7 hr previously with reserpine is greater than that extracted from medulla of saline-treated rats.
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PMID:Activation and nuclear translocation of protein kinase during transsynaptic induction of tyrosine 3-monooxygenase. 0 93

Two tryptic phosphopeptides containing the sites on the alpha and beta subunits of phosphorylase kinase which are phosphorylated by protein kinase, dependent on adenosine 3':5'-monophosphate (cyclic AMP), have been isolated and their amino acid sequences have been determined. 32P-labelled phosphorylase kinase, containing 1.9 mol phosphate per mol enzyme, was digested with an equimolar quantity of trypsin for 2.5 min at pH 7.0, 20 degrees C. This treatment released nearly all the 32P radioactivity associated with the beta subunit as trichloroacetic-acid-soluble material. Only a small proportion of the 32P radioactivity associated with the alpha subunit was solubilised, the remainder being removed in the trichloroacetic acid pellet. The beta-subunit tryptic phosphopeptide was completely resolved from traces of the alpha-subunit phosphopeptide by gel filtration on Sephadex G-25. Further purification by peptide mapping separated the phosphopeptide into four components, each derived from the same nine-amino-acid segment of the betachain, which was found to possess the sequence: Gln-Ser-Gly-Ser(P)-Val-Ile-Tyr-Pro-Leu-Lys. The four components were produced by the partial cyclisation of the N-terminal glutaminyl residue, and by the presence of two alleles for the beta subunit in the rabbit population, which led to a valine-isoleucine ambiguity. The alpha-subunit phosphopeptide was liberated from the trichloroacetic acid pellet by redigestion with trypsin. It was the largest component in the digest which remained soluble in 5% trichloroacetic acid, and obtained in a highly purified form by a single filtration on Sephadex G-50. The peptide comprised 39 amino acids of which nine were serine and three were threonine residues. Only one residue, the serine at position three from the amino terminus, was phosphorylated. The amino-terminal sequence of the peptide was shown to be: Arg-Leu-Ser(P)-Ile-Ser-Thr-Glu-Ser-Glx-Pro-Asx-Gly. The sequences confirm the stoichiometry of the reaction and the absolute specificity of cyclic-AMP-dependent protein kinase for just two of the 200 serine residues in the enzyme. These results and an inspection of the rate of phosphorylation of a number of skeletal muscle proteins, including each enzyme of the glycolytic pathway, lead to the conclusion that cyclic-AMP-dependent protein kinase is an extremely specific enzyme. The molecular basis of this specificity is discussed.
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PMID:The hormonal control of activity of skeletal muscle phosphorylase kinase. Amino-acid sequences at the two sites of action of adenosine-3':5'-monophosphate-dependent protein kinase. 16 50

The substrate specificity of the catalytic subunit of rabbit skeletal muscle 3': 5'-cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP: protein phosphotransferase) has been studied using the synthetic peptide Arg-Gly-Tyr-Ser-Leu-Gly corresponding to the sequence around serine 24, a phosphorylation site in reduced, carboxymethylated, maleylated (RCMM) chicken egg white lysozyme. This peptide served as a substrate for the enzyme and exhibited a 6-fold higher Vmax and a 100-fold higher Km than RCMM-lysozyme. Replacement of the arginine with glycine, histidine, or lysine resulted in a dramatic reduction in the Vmax. These results support the concept that arginine is an important residue in determining the substrate specificity of the protein kinase, predominantly influencing the Vmax of the phosphorylation reaction. Two synthetic peptides in which serine was replaced by an alanine acted as competitive inhibitors of phosphorylation of the synthetic peptide substrate and RCMM-lysozyme.
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PMID:Synthetic hexapeptide substrates and inhibitors of 3':5'-cyclic AMP-dependent protein kinase. 17 70

The 10000 X g supernatant fraction of brown fat from newborn rats catalyzed the cyclic AMP-dependent phosphorylation of both histone and a preparation of proteins from the same subcellular fraction (endogenous proteins). The apparent affinity for ATP was lower for the phosphorylation of the endogenous proteins than for the phosphorylation of histone. In order to discover whether the phosphorylation of histone and the endogenous proteins were catalyzed by different enzymes, the 100000 X g supernatant was fractionated by ion-exchange and adsorption chromatography. Three different cyclic AMP-dependent protein kinases and one cyclic AMP-independent protein kinase were separated and partially purified. Each of these enzymes catalyzed the phosphorylation of both substrates, and the difference in apparent Km for ATP remained. Neither affinity chromatography on histone-Sepharose, nor electrophoresis on polyacrylamide gels resulted in the separation of the phosphorylation of histone from that of the endogenous proteins of any of the partially purified kinases. Moreover, experiments in which the phosphorylated substrates were separated by differential precipitation with trichloroacetic acid showed that the endogenous proteins competitively inhibited the phosphorylation of lysine-rich histone. It is concluded that each of the partially purified kinase preparations contains protein kinase, which catalyzes the phosphorylation of both substrates. The difference in apparent Km for ATP was found to be due to the presence in the endogenous protein preparation of a low molecular weight compound which competes with ATP. This was not ATP nor the modulator protein. The ratio of the phosphorylation of endogenous proteins to that of histone was much higher for the cyclic AMP-independent kinase preparation than for the other enzymes. Electrophoresis of the endogenous substrates in the presence of sodium dodecyl sulphate showed that the enzyme phosphorylated a greater number of proteins than did the cyclic AMP-dependent kinases. The phosphorylation of endogenous proteins relative to that of histone was significantly lower for one of the cyclic AMP-dependent kinases than for the other two. This difference was not reflected in a different pattern of phosphorylation of the individual proteins of the endogenous mixture.
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PMID:Protein kinases and their substrates in brown adipose tissue from newborn rats. 17 73

The known amino acid sequences at the two sites on phosphorylase kinase that are phosphorylated by cyclic AMP-dependent protein kinase were extended. The sequences of 42 amino acids around the phosphorylation site on the alpha-subunit and of 14 amino acids around the phosphorylation site on the beta-subunit were shown to be: alpha-subunit Phe-Arg-Arg-Leu-Ser(P)-Ile-Ser-Thr-Glu-Ser-Glx-Pro-Asx-Gly-Gly-His-Ser-Leu-Gly-Ala-Asp-Leu-Met-Ser-Pro-Ser-Phe-Leu-Ser-Pro-Gly-Thr-Ser-Val-Phe(Ser,Pro,Gly)His-Thr-Ser-Lys; beta-subunit, Ala-Arg-Thr-Lys-Arg-Ser-Gly-Ser(P)-VALIle-Tyr-Glu-Pro-Leu-Lys. The sites on histone H2B which are phosphorylated by cyclic AMP-dependent protein kinase in vitro were identified as serine-36 and serine-32. The amino acid sequence in this region is: Lys-Lys-Arg-Lys-Arg-Ser32(P)-Arg-Lys-Glu-Ser36(P)-Tyr-Ser-Val-Tyr-Val- [Iwai, K., Ishikawa, K. & Hayashi, H. (1970) Nature (London) 226, 1056-1058]. Serine-36 was phosphorylated at 50% of the rate at which the beta-subunit of phosphorylase kinase was phosphorylated, and it was phosphorylated 6-7-fold more rapidly than was serine-32. The amino acid sequences when compared with those at the phosphorylation sites of other physiological substrates suggest that the presence of two adjacent basic amino acids on the N-terminal side of the susceptible serine residue may be critical for specific substrate recognition in vivo.
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PMID:The substrate specificity of adenosine 3':5'-cyclic monophosphate-dependent protein kinase of rabbit skeletal muscle. 19 23

Protein kinase was isolated from pigeon breast muscle. The preparation obtained was chromatographically homogeneous. The apparent Km varlue for histone H1 and ATP were 3,5-10(-5) M and 1,6-10(-5) M respectively. The purified enzyme displays high specificity for the lysine-rich histones (H1, H2b, H2a). The protein kinase activity is stimulated, 1,6-fold by cyclic AMP.
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PMID:[Isolation and some properties of protein kinase from pigeon breast muscle]. 19 86

Synthetic polypeptides were employed as substrates in kinetic analyses of the reaction mechanism for the catalytic subunit of a cyclic AMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) from calf thymus. This enzyme preparation was shown to catalyze the transfer of phosphate from ATP to histone H1 from calf thymus, as well as to two synthetic polypeptides, Arg-Lys-Ala-Ser-Gly-Pro (H1-6) and Arg-Arg-Lys-Ala-Ser-Gly-Pro (H1-7), corresponding to the amino acid sequence about serine-38 in calf H1. A related, basic heptapeptide corresponding to a sequence from pig liver pyruvate kinase, Leu-Arg-Arg-Ala-Ser-Leu-Gly (K), was also a substrate. The stoichiometry of peptide phosphorylation was established in each case as the transfer of 1 mol of phosphate from the gamma position of MgATP to the serine hydroxyl of 1 mol of the peptide. Steady-state, initial-velocity, kinetic parameters were determined for each substrate, using various concentrations of ATP. Under the conditions used, all synthetic peptides reacted with greater maximum velocities than whole histone H1. Nevertheless, the K(m) for H1, 54 muM, was lower than the K(m) values of the synthetic substrates. The most efficient substrate was peptide K, which had a V(max) of 50.6 mumol/min per mg of kinase and a K(m) of 63 muM. In the absence of peptide substrate no ATPase activity was detectable at a sensitivity of 0.05% of the rate of peptide phosphorylation, suggesting that ATP is not cleaved to form an unstable phosphoenzyme complex. The data are consistent with a sequential reaction mechanism involving a ternary complex between enzyme, polypeptide substrate, and ATP.
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PMID:Studies on the mechanism of phosphorylation of synthetic polypeptides by a calf thymus cyclic AMP-dependent protein kinase. 20 Sep 11

A phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) was partially purified from pig heart using as substrate H2B histone which had been phosphorylated at Ser-32 and Ser-36 by adenosine 3',5'-monophosphate-dependent protein kinase (EC 2.7.1.37). The enzyme had a molecular weight of approx. 250 000 and was converted to a smaller form with a molecular weight of approx. 30 000 upon treatment with ethanol. Phosphorylase alpha (EC 2.4.1.1) and phosphorylated H1 histone also served as substrates for both forms of the enzyme. The conversion of the large form of the enzyme to the small form decreased the phosphohistone phosphatase activity to 25-50% with a concomitant 7-fold increase in the phosphorylase alpha phosphatase activity. Ser-36 phosphate was removed 6- and 15-fold more rapidly than was Ser-32 phosphate by the large and small forms of the enzyme, respectively. Among Ser-36-containing tryptic phosphopeptides derived from phosphorylated H2B histone, Lys-Glu-Ser(P)-Tyr-Ser-Val-Tyr was the shortest phosphopeptide which was dephosphorylated at a significant reaction rate with the phosphoprotein phosphatase. The Km values for phosphorylated H2B histone and the tryptic phosphopeptide were 23.7 micron and 187.1 micron, respectively, with the large form, and 81.4 micron and 90.0 micron, respectively, with the small form of the enzyme.
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PMID:Comparison of two forms of pig heart phosphoprotein phosphatase. 20 53

The catalytic subunit of cyclic AMP-dependent protein kinase (from rabbit skeletal muscle; ATP:protein phosphotransferase, EC 2.7.1.37) was found to be irreversibly inactivated by chloromethyl ketone derivatives of lysine and phenylalanine, chemical reagents originally designed for labeling the active sites of the proteolytic enzymes trypsin and chymotrypsin. This inactivation was shown to occur at pH 7.5 and 22 degrees C, conditions under which chemically related alkylating reagents such as chloroacetamide and chloroacetic acid (which do not possess the amino acid side chain) fail to inactivate the enzyme. In the case of the chloromethyl ketone derivative of N alpha-tosyl-L-lysine, the enzyme could be protected by its nucleotide substrate (MgATP), by one of its protein substrates (histone H2b), and by its regulatory subunit which, upon binding, shields the active site of the catalytic subunit. Differential labeling experiments, together with kinetic studies of the rates of modification of the sulfhydryl groups in the enzyme before and after inactivation with the chloromethyl ketone, suggest that the loss of activity is associated with one (kinetically characterized) sulfhydryl group present either at the active site of the enzyme or at a site intimately associated with it. The general implications of these results regarding the interpretation of affinity labeling experiments carried out in complex mixtures of proteins or under in vivo conditions are discussed.
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PMID:Affinity labeling of the catalytic subunit of cyclic AMP-dependent protein kinase by N alpha-tosyl-L-lysine chloromethyl ketone. 22 53


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