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)

Rat kidney plasma membranes prepared by the method of FITZPATRICK et al. (J Biol. Chem. 244, 3561, 1969) show protein kinase activity as well as specific cAMP binding activity (diss. const. 1.3 x 10-9 M). However, no stimulation of kinase activity by cAMP is observed in presence of exogenous substrates (e.g. histone) and only poor stimulation with endogenous substrates in the membrane could be shown. At high ionic strength (1 M NaCl) cAMP independent protein kinase activity can be solubilized. Low ionic strength buffer (1 mM Tris-HCl pH 7.4 1 mM EDTA) and non-ionic detergents (Lubrol PX, Lubrol WX and Triton X 100) are able to solubilize both protein kinase activity and cAMP binding activity. Protein kinase activity seemed to be only loosely associated with the membrane, whereas cAMP binding protein appears to be more firmly fixed into the membrane structure. In addition we have found that membranes serve as a good substrate for cytosol protein kinase (s) and Ca-ion concentration influences the effect of cAMP on protein kinase activity. Dependent on the increase of Ca-ion concentration the effect of cAMP on protein kinase changes from activation to inhibition.
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PMID:Some aspects of rat kidney plasma membrane cAMP-receptor and its connection with protein kinase activity. 18 76

The time course for epinephrine stimulation of lypolysis, cyclic AMP accumulation and activation of protein kinase was studied in adipose tissue from hypophysectomized rats. Triglyceride breakdown, as assessed by glycerol release, increased rapidly in response to epinephrine, maintained a constant rate as long as the hormone was present, and decreased rapidly to basal values when the hormone was removed. Cyclic AMP accumulation was transient peaking within 3 min of exposure to epinephrine and then declining to levels indistinguishable from basal by 9 min. Protein kinase activity in extracts also peaked at 3 min and thereafter declined to a level approximately 25% greater than resting activity. Peak levels of cyclic AMP, steady state levels of protein kinase activity and the rate of glycerol production were all related in a dose dependent manner to the concentration of epinephrine. These observations suggest that the spike in cyclic AMP levels may be necessary to trigger the activation of lipolysis, but was not sufficient to sustain an accelerated rate of triglyceride breakdown. Continued activation of protein kinase, however, may be essential to sustained lipolysis.
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PMID:Studies on the mechanisms of epinephrine stimulation of lypolysis. 18 36

Protein phosphokinase activity from a 0.5 M NaCl extract of purified porcine ovary nuclei has been resolved by Sephadex G-200 gel filtration into three forms of kinase, protein kinase I and III, both independent of adenosine 3':5'-monophosphate (cyclic AMP), and cyclic-AMP-dependent protein kinase II. Cyclic AMP-binding activity was associated with protein kinase II but not with protein kinases I and III. Protein kinases I, II, and III exhibited different cyclic nucleotide dependency and substrate specificity. Protein kinase II was inhibited by a heat-stable protein from rabbit skeletal muscle, whereas protein kinases I and III were not inhibited. According to previously established criteria [Traugh, J.A., Ashby, C.D. and Walsh, D.A. (1974) nuclear protein kinase II can be classified as cyclic-AMP-dependent protein kinase consisting of regulatory and catalytic subunits. Nuclear protein kinases I and III are cyclic-AMP-independent enzymes. Evidence for the identity of nuclear cyclic-AMP-dependent protein kinase II with cytosol (105 000 X g supernatant fraction) cyclic-AMP-dependent protein kinase was obtained in several ways. Nuclear and cytosol cyclic-AMP-dependent protein kinases exhibited identical elution characteristics on DEAE-cellulose and Sephadex G-200 indicating that both kinases are of similar molecular size and possess similar ionic charge. Both kinases exhibited an identical Km for ATP of 8 muM, showed similar substrate specificity, and revealed similar antigenic properties. Cyclic-AMP-dependent protein kinase II was also identified in nuclei isolated in nonaqueous media, eliminating the possibility that the cyclic-AMP-dependent protein kinase activity identified in nuclei isolated in aqueous media may have arisen as the result of cytoplasmic contamination. After incubation of neonatal porcine ovaries which lack nuclear cyclic-AMP-dependent protein kinase with 0.1 muM 8-p-chlorophenylthio cyclic AMP, considerable cyclic-AMP-dependent protein kinase II activity was identified in nuclei isolated in nonaqueous media. From these data it is concluded that the nuclear cyclic-AMP-dependent protein kinase II is related to or identical with the ovary cytoplasmic cyclic-AMP-dependent protein kinase, supporting the concept that nuclear cyclic-AMP-dependent protein kinase is of cytoplasmic origin.
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PMID:Evidence for the identity of nuclear and cytoplasmic adenosine-3':5'-monophosphate-dependent protein kinase from porcine ovaries and nuclear translocation of the cytoplasmic enzyme. 19 8

Protein kinase activity has been studied in four human adrenocortical tumors and compared to the one of the normal human adrenal. In two cases where the lack of action of ACTH was related to an anomaly of ACTH receptor, the protein kinase activity was normal. In the other two cases the ACTH receptor was normal, but the protein kinase activity was different from that of the normal adrenal. In one of these cases where the steroidogenesis response of isolated tumor cells to ACTH and DcAMP was higher than in normal adrenal, basal and cAMP stimulated protein kinase activities were significantly higher than those of the normal adrenal, but the activation constants of both nucleotides were similar to those of the normal gland. In the other case, the basal and the cAMP stimulated protein kinase activities were significantly lower, as well as the activation constant of cAMP. However, the binding affinity of 3H-cAMP was normal. Normal adrenal cytosol contains three protein kinases, as resolved by DEAE-cellulose, two of which designated I and II, are cAMP-dependent. The DEAE-cellulose chromatography of the last tumor showed a loss of isoenzyme II. In addition, the protein kinase eluted at the same molarity as that of isoenzyme I of the normal adrenal was not activated by cAMP. Therefore, the lack of response to ACTH of some adrenocortical human tumors may be attributed either to an anomaly of the ACTH receptor or to some defect of the cAMP-dependent protein kinase.
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PMID:Adenosine 3'5'-cyclic monophosphate dependent protein kinase in human adrenocortical tumors. 19 Feb 57

Protein kinase activity was examined in supernatants from super-sensitive and subsensitive rat pineal glands both in the presence and absence of added cAMP. After a 20 min exposure to 1-isoproterenol, in vivo or in organ culture, supersensitive pineals displayed a greater decrease in protein kinase activity (in the absence of added cAMP) than did subsensitive glands. Furthermore, exposure of rats to 24 h light, a procedure which produces a supersensitive response to beta-adrenergic stimulation, results in a 50% increase in protein kinase activity (with or without added cAMP) as compared to the activity in pineals obtained after 12 h darkness, when the glands are subsensitive. Kinetic analysis revealed a 50-100% increase in the Vmax for ATP, histone, and cAMP. This increase in protein kinase was not prevented by prior treatment of rats with cycloheximide. The diminished kinase activity in subsensitive glands did not appear to be due to an increase in the heat-stable protein kinase inhibitor. Protein kinase activity also increased (in the presence or absence of added cAMP) after noradrenergic input to the gland was reduced by denervation or depletion of neurotransmitter. Thus, pineal protein kinase may participate in the effects of beta-adrenergic agonists (e.g. the induction of serotonin N-acetyltransferase) and in the regulation of the sensitivity of the gland to beta-adrenergic stimulation.
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PMID:Regulation of protein kinase in rat pineal: increased Vmax in supersensitive glands. 19 Feb 78

A protein kinase, designed KII, has been purified 5000-fold from Novikoff ascites tumor cells. The purification procedure also allows for the purification of a second major protein kinase, designated KI, as well as RNA polymerase I and II. Purified KII has a sedimentation constant of 7.6 S and a Stokes radius of 39 A, suggesting a molecular weight of about 122000. Polyacrylamide gel electrophoresis of the enzyme in the presence of sodium dodecyl sulfate suggests the enzyme is composed of subunits of molecular weights 44 000, 40 000, and 26 000 present in a molar ratio of 1:1:2. Incubation of the enzyme alone in the presence of [gamma-32P]ATP results in the phosphorylation of the 26 000-dalton subunit. Protein kinase II actively phosphorylates phosvitin, casein, and nonhistone chromosomal proteins but does not phosphorylate basic proteins such as histones or protamine to an appreciable extent. Km values of 3.6 micron for ATP and 6.5 micronM for GTP were determined in the presence of 4mM Mg2+. The enzyme is neither stimulated by cyclic adenosine 3',5'-monophosphate or cyclic guanosine 3', 5'-monophosphate nor inhibited by the regulatory subunit of rabbit muscle protein kinase. Its activity is stimulated by KCl at concentrations below 0.2 M and inhibited by higher concentrations.
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PMID:Purification and characterization of Novikoff ascites tumor protein kinase. 19 79

Three different types of protein kinases (ATP: protein phosphotransferase, EC 2.7.1.37) were isolated and partially purified from a mouse plasmacytoma microsomal KCl wash fraction, then chromatographed on DEAE cellulose and phosphocellulose. The three protein kinase activities designated by protein kinase I, II and III were characterized with respect to their capacity to utilize [gamma-32P]ATP and [gamma-32P]GTP, to interact with cyclic AMP, stimulation by cyclic AMP, substrate specificity and sedimentation behaviour on glycerol gradient centrifugation. Protein kinase I was found to be cyclic AMP dependent and preferentially phosphorylated histones. Protein kinase II and III were insensitive to cyclic AMP, protein kinase II preferentially phosphorylated histones and the protein(s) of a ribosomal KCl wash fraction eluted from DEAE cellulose between 0.2 and 0.35 M KCl and termed "PPx". Protein kinase III phosphorylated casein and ribosomal proteins to a great extent. Studies with glycerol density gradient centrifugation indicated that protein kinase I sediments as a component of about 4.4 S, protein kinase II of 4.3 S and protein kinase III of 3 S. Chromatography on phosphocellulose of the protein kinases isolated from purified free polysomes showed the same type of protein kinases as those from microsomes. So it appears unlikely that protein kinase I and II were contaminants from the cytosol.
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PMID:Resolution and general properties of different types of ribosomal protein kinases in mouse plasmocytoma. 19 98

Protein kinase activity was detected and assayed directly on polyacrylamide gels after disc electrophoresis of the 100,000 X g supernatant fraction of brown adipose tissue of infant rats. Nine major bands of activity were detected, eight of which could be stimulated by cAMP or inhibited by the cAMP-dependent protein kinase inhibitor protein. This electrophoretic technique revealed heterogeneity in the cAMP-dependent protein kinase activity eluted from DEAE-cellulose by high concentrations of salt, but not in the peak of activity eluted by low concentrations of salt. The catalytic properties and substrate specificities of the kinases in the various bands were studied while the enzymes were still in the gels. The activity in each band differed from each of the others in at least one of these properties. The activities of the protein kinases in brown fat changed as the animals grew, and each band exhibited a distinct and unique developmental pattern. The major changes in kinase activities occurred in the immediate post-parturition period, then at 15 days after birth and at weaning. These developmental stages coincide with the periods during which the tissue undergoes changes in the rate of its proliferation, differentiation, and functional activity.
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PMID:Protein kinases in brown adipose tissue of developing rats. Electrophoretic separation and assay of soluble protein kinases on polyacrylamide gels and a study of their properties and changes during development. 19 49

Protein kinase from the bull myocardium tissue was separated by means of the stepped gradient of buffer concentrations on DEAE-cellulose. Sensitivity of the obtained fractions to cAMP was studied. Protein kinase isolated at elution by 0.3 M potassium-phosphate buffer from DEAE-cellulose is less sensitive to cAMP than protein kinase isolated according to Kuo. A decrease in the content of cAMP is established in the tissues of the skeletal muscles and adrenals of rats after long physical loading. No statistically significant changes are found in the level of cAMP under the same conditions in the myocardium and brain tissues.
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PMID:[Characteristics of protein kinases from myocardium and their use for studying cAMP content in rat tissues after muscular activity]. 19 75

The heat-stable protein inhibitor (Walsh, D. A., et al. (1971), J. Biol. Chem. 246, 1977--1985) of the cyclic adenosine 3',5'-monophosphate dependent protein kinase has been isolated in pure form from rabbit skeletal muscle after a 430 000-fold purification with a 47% yield. The four-step procedure involves sequentially a heat treatment, batchwise anion and cation exchange, and affinity chromatography on protein kinase catalytic subunit covalently coupled to Sepharose 4B. The inhibitor is an acidic protein (pI = 4.24) of molecular weight 11 300. It contains 98 amino acid residues none of which contains sulfur and only 2 (phenylalanine and tyrosine) are aromatic. The NH2-terminus is blocked. The muscle content is ca. 0.6 mg of inhibitor per L of intracellular water. The inhibitor is tightly bound to the catalytic subunit of protein kinase (Ki congruent to 2 X 10(-9) M) and acts competitively with respect to the protein substrates. Protein kinase recognizes a short stretch of the inhibitor sequence, in which arginyl side chains play a crucial role. A study of various competitive inhibitors of the kinase confirms the importance of guanidino groups and hydrophobic side chains in the specific interaction with the substrate binding site.
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PMID:Isolation and properties of the rabbit skeletal muscle protein inhibitor of adenosine 3',5'-monophosphate dependent protein kinases. 19 23


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