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)

Previous studies with isolated adrenocortical carcinoma 494 cells from this laboratory have indicated that the lack of cyclic adenosine 3':5'-monophosphate (cyclic AMP) control in steroidogenesis in the tumor may be due to the defective cyclic AMP-dependent protein kinase enzyme system. This paper describes the partial purification of such an enzyme. Purification was achieved by precipitation of the tumor homogenate with 30 and 45% ammonium sulfate, adsorption on 3% calcium phosphate gel, and chromatography on DEAE-cellulose. Four major protein peaks were isolated. Peak 2 showed cyclic AMP-binding activity and was investigated further for its kinetic properties. In contrast to the cyclic AMP-dependent protein kinase enzyme found in the normal adrenal gland, the enzyme specifically bound cyclic AMP but failed to phosphorylate exogenous histone. It is postulated that lack of the cyclic nucleotide-dependent kinase activity of the protein kinase enzyme may be responsible for the loss of cyclic AMP-regulated corticosterone synthesis in adrenocortical carcinoma cell. It is further shown that the tumor cyclic AMP-binding enzyme undergoes endogenous phosphorylation, which indicates that it has kinase activity but it is independent of cyclic AMP.
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PMID:Partial purification and characterization of the defective cyclic adenosine 3':5'-monophosphate binding protein kinase from adrenocortical carcinoma. 19 24

Myocardial acidic non-histone nuclear proteins (NHPs) contain endogenous protein kinase activity. Phosphocellulose chromatography of purified NHPs identifies nine separate peaks of protein kinases which can phosphorylate both endogenous and exogenous substrates to a variable degree; endogenous NHPs are the best substrates. Cyclic AMP-stimulated protein kinase induced phosphorylation of endogenous and exogenous substrates; the extent of this stimulation varied according to the protein kinase fraction and substrate used. Cyclic AMP also enhanced NHP-induced stimulation of RNA polymerase activity. This enhancement was dependent on protein kinase-induced phosphorylation of NHPs since it was prevented by alkaline phosphatase pretreatment. It is concluded that nuclear protein kinases regulate myocardial RNA synthesis by enhancing phosphorylation of NHPs and that this regulation is under cyclic AMP control.
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PMID:Adenosine 3',5'-monophosphate-dependent protein kinases of myocardial non-histone nuclear proteins. 19 45

The effect of bilirubin on protein kinase activity has been studied. Bilirubin inhibits the binding of cyclic AMP to protein kinase. It also inhibits the phosphorylation of histone. The inhibitory action of bilirubin is competitive, and increased amounts of cyclic AMP relieved the inhibition.
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PMID:Bilirubin inhibition of protein kinase: its prevention by cyclic AMP. 19 12

Guanosine 3',5'-monophosphate (cyclic GMP)-dependent protein kinase partially purified from silkworm pupae reacts preferentially with H1, H2A, and H2B histones but not with H3 AND H4 histones. However, the latter can serve as substrates in the presence of a stimulatory modulator as described by Kuo and Kuo (J. Biol. Chem. 251, 4283-4286 (1976)). With H2B histone as substrate high Mg2+ concentrations (50-100 mM) are necessary for the maximum rate of reaction. Although effects of the modulator and Mg2+ vary significantly with the histone fractions employed, analysis on the phosphorylation of histone fractions provides evidence that cyclic GMP-dependent protein kinase possesses an intrinsic activity that is similar to that of adenosine 3',5'-monophosphate-dependent protein kinase.
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PMID:Intrinsic activity of guanosine 3',5'-monophosphate-dependent protein kinase similar to adenosine 3',5'-monophosphate-dependent protein kinase. I. Phosphorylation of histone fractions. 19 69

A heat-and acid-stable protein inhibitor of phosphorylase phosphatase is present in a highly purified preparation of protein inhibitor of cyclic AMP-dependent protein kinase from rabbit skeletal muscle. Although these two inhibitors have strikingly similar properties to each other, such as sensitivity to trypsin and behavior on gel permeation chromatography, they can be separated by polyacrylamide disc gel electrophoresis. This indicates that the phosphatase-inhibitory and kinase-inhibitory activities reside with different protein species. The inhibition of both the enzymes is not altered by incubating the inhibitor preparation with a general phosphoprotein phosphatase, with phosvitin kinase, or with cyclic AMP-dependent protein kinase. Inhibition of phosphorylase phosphatase is of a non-competitive type supporting the idea that the phosphatase inhibitor is not an alternative substrate for the enzyme. Inhibition of phosphatase activity is selective in that it does no occur when phosphorylated histone or phosphorylated protamine are used as substrates.
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PMID:Protein inhibitors of phosphorylase phosphatase and cyclic AMP-dependent protein kinase from rabbit skeleta muscle. 19 98

The properties of purified mammalian adenosine 3':5'-cyclic monophosphate (cAMP)- and guanosine 3':5'-cyclic monophosphate (cGMP)-dependent protein kinases were compared. Several physical characteristics of the two enzymes were similar, including size, shape, affinity for cyclic nucleotide binding, and K(m) for ATP. In addition, the amino acid composition of the two proteins indicated a close composition homology (70-90%). Both cyclic nucleotide-dependent protein kinases catalyzed phosphorylation of rat liver pyruvate kinase (EC 2.7.1.40) and fructose 1,6-diphosphatase (EC 3.1.3.11), rabbit skeletal muscle glycogen synthase (EC 2.4.1.11) and phosphorylase b kinase (EC 2.7.1.38), and calf thymus histone H(2)b. The phosphorylation of several synthetic peptides and of trypsin-sensitive and trypsin-insensitive sites in glycogen synthase suggested similar recognition sites on the protein substrates for the two kinases. The cAMP-dependent protein kinase was the better catalyst with each protein or peptides substrate. The results suggest that the two enzymes evolved from a common ancestral protein.
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PMID:Adenosine 3':5'-cyclic monophosphate- and guanosine 3':5'-cyclic monophosphate-dependent protein kinases: possible homologous proteins. 19 77

The Sertoli cell of the rat testis contains two cytoplasmic forms of adenosine 3',5' monophosphate (cyclic AMP)-dependent protein kinase, designated as Peak I and Peak II, which change in relative proportion during Sertoli cell maturation. Peak I and Peak II differ in their subunit interaction. Thus, while the substrates, ATP and histone, affect cyclic AMP binding to Peak I, neither of these compounds affect the binding of cyclic AMP to the Peak II enzyme. The effects of cyclic AMP binding to Peak I appear to be due to the fact that histone and high ionic strength cause dissociation of the Peak I holoenzyme, whereas ATP stabilizes the holoenzyme complex against dissociation. The Peak II holoenzyme is not affected by either salt of histone and is only dissociated by cyclic AMP. Once dissociated, the subunits of Peak II will rapidly reassociate under low salt conditions whereas the subunits of Peak I will not reassociate. By utilizing the distinct properties of Peak I and Peak II, it is possible to demonstrate the activation of both Peak I and Peak II Sertoli cell protein kinase in response to FSH.
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PMID:Characterization and follicle stimulating hormone activation of Sertoli cell cyclic AMP-dependent protein kinases. 19 15

A protein kinase which phosphorylated histone and protamine was partially purified from bovine cerebellum. Casein and phosvitin were inert as substrates. The enzyme did not require any cyclic nucleotide. A sulfhydryl compound such as 2-mercaptoethanol, glutathione, or cysteine was necessary for the reaction. The optimum pH was 8.5 to 9.0 Km values for ATP and whole histone were 3.3 X 10(-6) M and 150 microgram/ml, respectively. The optimum concentration of Mg2+ varied with histone fractions employed; with H2B histone as substrate the enzyme was most active at 50 to 100 nM Mg2", whereas with H1 and H2A histones the maximum activity was observed at 5 to 10 mM Mg2+ and with H3 and H4 histones the enzyme was active over a range of 5 to 75 mM Mg2+. The enzyme phosphorylated Ser-32 and Ser-36 in H2B histone and Ser-38 in H1 histone, although the reaction with Ser-36 in H2B histone was very slow. The molecular weight was 6.4 X 10(4). The sedimentation coefficient and Stokes radium were about 4.5 and 29 A, respectively. The enzyme showed heterogeneity upon isoelectrofocusing electrophoresis with isoelectric points of 5.6, 6.0, and 6.6. The enzyme was not inhibited by protein inhibitor nor by the regulatory subunit of cyclic AMP-dependent protein kinase. Preliminary analysis suggested that the enzyme was produced from its precursor protein by a limited proteolytic reaction.
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PMID:Studies on a cyclic nucleotide-independent protein kinase and its proenzyme in mammalian tissues. I. Purification and characterization of an active enzyme from bovine cerebellum. 19 93

Nuclear and cytoplasmic protein kinases were measured during the traverse of synchronous CHO cultures through G1 into S phase. Cells were synchronized by selective detachment of cells blocked in metaphase using colcemid. Nuclei were isolated and the protein kinases extracted from the nuclear preparation with 0.6 M NaCl. This procedure solubilized greater than 90% of the total protein kinase activity present in the nuclear preparation. DEAE chromatography of this extract showed 5 apparently different ionic forms of nuclear protein kinases. The nuclear protein kinases preferred casein and phosvitin to histone as substrates and were cyclic AMP-independent. Nuclear protein kinase activities increased greater than two-fold, when expressed as units of activity per cell nucleus, during G1 phase traverse, concomitant with a 70% increase in nuclear non-histone proteins (those soluble in 0.6 M NaCl). This resulted in only a 40% increase in the specific activities (units/microgram protein in 0.6 M NaCl extractable nuclear fraction) of these enzymes as cells progressed through G1 into S phase. This was in contrast to cytoplasmic cyclic AMP-dependent protein kinase activities which also increased two-fold during progression through G1 phase while total cellular protein increased less than 20%. Activation of, as well as synthesis of, cyclic AMP-dependent cytoplasmic protein kinases during G1 phase suggests a regulatory mechanism for precise temporal phosphorylation, whereas the constant specific activity in nuclear kinases during cell cycle is more compatible with the maintenance of bulk phosphorylation processes in the nucleus.
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PMID:Cytoplasmic and nuclear protein kinases during the cell cycle. 20 Feb 70

Both cyclic AMP-binding and cyclic AMP-dependent protein kinase activities exist in Chinese hamster ovary cell extract. Competition experiments demonstrate that the binding is specific for cyclic AMP. All cellular elements including nucleus, mitochondria, plasma membrane, microsome, ribosome and cytosol contain both activities. Binding activity is highest in the cytosol and lowest in the nucleus. Each fraction contains endogenous protein kinase activity which is insensitive to cyclic AMP activation. When histone was used as a substrate, protein kinase activity in all fractions was stimulated by cyclic AMP (with the highest in cytosol and lowest in the nucleus) and inhibited by Walsh's protein kinase inhibitor.
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PMID:Studies on adenosine 3',5'-phosphate-binding and adenosine 3',5-phosphate-dependent protein kinase activities associated with subcellular fractions of Chinese hamster ovary cells. 20 Feb 77


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