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)

The relaxing effect of two positive inotropic interventions was studied in the isolated rat heart beating at constant rate and perfused at constant coronary flow. Experiments were performed under isotonic or isometric conditions during heart perfusions with Ca2+, 3.5 X 10(-3) M, and with isoproterenol, 10(-7) to 10(-8) M. Changes induced in maximal velocity of contraction (+L or +T) and maximal velocity of relaxation (-L or -T) were analyzed as the ratio between both maximal velocities (+L/-L or +T/-T). For similar increments in the amount of the apex-to-base shortening or in developed tension during Ca2+ or isoproterenol perfusions, the effect on the maximal velocity of relaxation differed for each intervention. High Ca2+ perfusion increased velocities of contraction and relaxation proportionally without significant changes in their ratio. Isoproterenol increased -L or -T more than +L or +T and the ratio showed a significant fall both in isotonic and isometric experiments (+L/-L, -0.33 +/- 0.11 and +T/-T, -0.38 +/- 0.09; P less than 0.01). The relaxing effect of the beta agonist seems to be related to the activation of the protein kinase system since perfusions with dibutyryl 3',5'-cAMP had a greater effect on the relaxation of the hearts.
Am J Physiol 1977 Sep
PMID:Effect of isoproterenol on relation between maximal rate of contraction and maximal rate of relaxation. 91 Sep 31

A nuclear protein kinase that shows a high degree of substrate specificity for the phosphorylation of the acidic proteins casein, phosvitin and non-histone chromatin proteins, rather than the basic proteins histones and protamine, was partially purified from lactatingrat mammary gland. The enzyme is associated with the acidic protein fraction of chromatin. Nuclear kinase requires Co(2+) for activity, and other bivalent cations such as Mg(2+) and Mn(2+) can substitute partially for Co(2+). The kinase is further activates (2-3-fold) by various salts, their concentration for maximum stimulation being: NaCl, 150mm; KCl, 200mm; sodium acetate, 300mm. The sedimentation coefficient of the nuclear kinase is 8.9S and its mol.wt. is approx. 300000 by gel-exclusion chromatography. The enzyme is not activated by cyclic AMP or cyclic GMP and is inhibited neither by the regulatory subunit of mammary cyclic AMP-dependent protein kinase nor by the heat-stable protein kinase inhibitor from ox heart. Analysis of (32)P-labelled protein products reveals that the kinase transfers the terminal phosphate of ATP to serine and threonine residues of proteins. The enzyme, however, has specificity for the phosphorylation of threonine in casein and serine in phosvitin. Molecular size and enzymic characteristics of the nuclear protein kinase are clearly different from those of the cytosol enzyme previously characterized.
Biochem J 1977 Sep 01
PMID:Purification and properties of a nuclear protein kinase from rat mammary gland. 92 60

A casein kinase was isolated and purifed from rabbit reticulocytes. About 90% of the enzyme activity co-sedimented with the ribosomal fraction, whereas about 10% of the enzyme activity was found in the ribosome-free supernatant. Both casein kinases (the ribosome-bound enzyme as well as the free enzyme) showed identical activity and the same molecular weight. On sodium dodecyl sulphate/polyacrylamide-gel electrophoresis a single band of about 70 000 mol.wt. was observed. Sucrose-gradient analysis, however, showed that the enzyme activity sedimented with a s20,w of approx. 7.5S. This observation suggested that the casein kinase is a dimer composed of subunits of identical molecular weight. The enzyme utilizes GTP as well as ATP as a phosphoryl donor. It preferentially phosphorylates acidic proteins, in particular the model substrates casein and phosvitin. Casein kinase is cyclic AMP-indepenoent. The Km values for ATP and GTP with phosvitin as a substrate were determined as 1.2 and 8.8 micrometer respectively.
Biochem J 1977 Sep 01
PMID:Purification and properties of a ribosomal casein kinase from rabbit reticulocytes. 92 64

Meiosis reinitiation has been triggered by injection of beef heart protein kinase or rabbit phosphorylase kinase into Xenopus laevis oocytes. Successful injections are followed by germinal vesicle breakdown, chromosome condensation, formation of a normal meiotic spindle, and appearance of an amplifiable maturation promoting factor. Meiosis reinitiation does not occur when the enzymes are introduced into the oocytes simultaneously with EGTA or after pretreatment with cycloheximide. Antipain, an antiprotease which abolishes the response of oocytes to progesterone, does not suppress the meiosis reinitiation induced by injection of protein kinase or phosphorylase kinase.
J Exp Zool 1976 Sep
PMID:Induction of meiosis by injection of heterologous protein kinase and phosphorylase kinase in Xenopus laevis oocytes. 96 20

The nonhistone proteins of Ehrlich ascites tumor chromatin have been separated into a loosely bound and two tightly bound protein fractions by sequential extraction of chromatin with 0.35 M NaCl and 2 M NaCl:5 M urea. The nonhistone proteins thus obtained were examined for their chemical composition and distribution of DNA polymerase, RNA polymerase, and protein kinase activities. In addition, the effect of these nonhistone proteins on transcription of DNA in vitro has been determined. The results indicate that these nonhistone proteins, fractionated on the basis of their extractability, exhibit varied compositional characteristics and play different functional roles in the synthesis of DNA and RNA and in the possible control of gene activity.
Cancer Res 1976 Sep
PMID:A comparison of the loosely bound and tightly bound nonhistone proteins from Ehrlich ascites tumor chromatin. 97 79

The protein substrate specificity of the catalytic subunit of rabbit skeletal muscle cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase) has been studied using genetic variants of beta casein. It was found that beta casein-B was phosphorylated at a much greater rate than beta caseins A1, A2, A3, or C. The enhanced phosphorylation of beta casein-B, as compared with the most common variant A2, was attributed to an arginine substitution for a serine at position 122, which caused a nearby residue, serine 124, to become a phosphorylation site for the protein kinase. These results further support the concept that the local primary structure is important in specificity and that arginine may be a specific determinant common to all the local phosphorylation site sequences recognized by the cyclic AMP-dependent protein kinase.
Proc Natl Acad Sci U S A 1975 Sep
PMID:Substrate specificity of the cyclic AMP-dependent protein kinase. 105 31

The chicken ovalbumin gene is subject to multihormonal regulation. Maximal expression of it requires not only the synergistic effects of estrogen and corticosterone, but also the permissive effects of insulin. In addition to effects on transcription, the stability of its message is greatly enhanced by estrogen. Furthermore, two signal transduction pathways involving protein kinases have been implicated in the regulation of the ovalbumin gene. To better define the role of second messengers on expression of the ovalbumin gene, the effects of the protein kinase-C (PKC) and the cAMP-dependent protein kinase (PKA) pathways on the endogenous levels of ovalbumin mRNA and the transcription of an ovalbumin fusion gene were investigated. Primary cultures of oviduct cells were treated with phorbol 12-myristilate 13-acetate (an activator of PKC) or with forskolin and 3-isobutyl-1-methylxanthine (an activator of PKA) alone, activators plus estrogen and corticosterone, or activators plus both steroids and insulin. The results indicate that phorbol 12-myristilate 13-acetate causes a dramatic destabilization of ovalbumin message, resulting in a reduction in ovalbumin mRNA levels. In contrast, the activators of the PKA system can substitute for insulin and, thereby, increase expression of the ovalbumin gene synergistically with the steroids. The effect of the activators of the PKA system is at the level of transcription. Thus, in chicken oviduct cell cultures, the PKA and PKC signal transduction pathways act in opposing ways to modulate the steroid-induced expression of the ovalbumin gene.
Mol Endocrinol 1992 Sep
PMID:Regulation of expression of the chicken ovalbumin gene: interactions between steroid hormones and second messenger systems. 127 83

The regulation of Cl- channels in human myoballs by G proteins was studied using whole-cell and inside-out patch recordings. After perfusion of the cell with 0.1 mM GTP[gamma S], the specific Cl- conductance, GCl, at standard resting potential (-85 mV) was increased from 5.9 microS/cm2 to 103 microS/cm2, and the kinetics upon stepping the potential to positive values was changed from an activating current with very slow inactivation to a fast inactivating current with no potential-dependent activation. These effects were not affected by the simultaneous blockade of several signal cascades involving G proteins. Addition of the protein kinase blockers PKI (25 microM), H8 (10 microM), or of the phospholipase-A2-blocking agent quinacrine (10 microM), had not much influence on these GTP[gamma S] effects. Buffering of the intracellular Ca2+ concentration (0.1 microM) or addition of the Ca2+/calmodulin antagonist trifluoperazine (50 microM) was also without effect. Pre-incubation of the cells with pertussis toxin or with cholera toxin did not change GCl. In excised inside-out patches voltage-clamped at -85 mV, application of GTP[gamma S] influenced the "intermediate" Cl- channel, the Cl- channel type having the highest density in these cells, by increasing the number of transitions in a half-conductance state. The probability of the channel being in one of the two conducting states rose from 0.015 to 0.67, and the kinetics of the single-channel currents was changed so that, on average, it was similar to the whole-cell current kinetics seen after application of GTP[gamma S]. It is concluded that a G protein is directly interacting with these channels.
Pflugers Arch 1992 Sep
PMID:Chloride channels in cultured human skeletal muscle are regulated by G proteins. 127 15

We have studied the effect of protein kinase C and protein kinase A activation, and phosphatase inhibition on two different stimuli with distinct mechanisms of action. The first stimulus is compound 48/80, and its action is mediated probably by a Gi-protein, while the other is sodium fluoride, which unspecifically activates G-proteins. We established a comparative study because the action of compound 48/80 is calcium-independent, while fluoride is strictly calcium-dependent. The activation of protein kinase C was attained with the phorbol esther 12-O-tetradecanoylphorbol-13-acetate, protein kinase A was activated by increasing cAMP levels with forskolin or rolipram, and the phosphatase activity was inhibited with okadaic acid (OA), which inhibits phosphatases type 1 and 2A. Our results show that OA enhances the response to fluoride and compound 48/80 in the absence of calcium, and we conclude that calcium has a negative feedback role on the cell response. Protein kinase A activation strongly inhibits the response to fluoride, and the results show a positive regulation of protein kinase C and a negative regulation of protein kinase A over fluoride response. As previously reported by other authors for the ionophore A23187, TPA notably potentiates the response to fluoride, which supports its possible modulatory role on extracellular calcium-dependent stimuli.
Agents Actions 1992 Sep
PMID:Influence of protein kinase C, cAMP and phosphatase activity on histamine release produced by compound 48/80 and sodium fluoride on rat mast cells. 128 Sep 5

The growth of new blood vessels plays an important role in the pathogenesis of several diseases including cancer, diabetes, and arthritis. Beta-cyclodextrin tetradecasulfate, when administered with an appropriate steroid inhibits angiogenesis, and can stimulate angiogenesis when given alone. The regulation of angiogenesis is not well understood, and the mechanism of action of beta-cyclodextrin tetradecasulfate is similarly not well defined. Ecto-protein kinase activity that utilizes extracellular ATP has recently been reported on several types of cells. Human neutrophils appear to possess two distinct ecto-protein kinase activities; one that phosphorylates exogenous substrates including vitronectin and basic fibroblast growth factor, and one that phosphorylates endogenous cell-surface proteins. This report shows that beta-cyclodextrin tetradecasulfate inhibits the phosphorylation of the exogenous substrates casein, vitronectin (the major ecto-protein kinase substrate in serum), and basic fibroblast growth factor by human neutrophil ecto-protein kinase activity. In contrast, beta-cyclodextrin tetradecasulfate had no effect on the phosphorylation of endogenous cell-surface proteins by the neutrophil ecto-protein kinase activity. Ecto-protein kinase activity that was inhibited by beta-cyclodextrin tetradecasulfate was also detected on porcine aortic and human umbilical vein endothelial cells. The effects of beta-cyclodextrin tetradecasulfate on ecto-protein kinase activities may play a role in its effects on angiogenesis.
Cell Mol Biol 1992 Sep
PMID:The angiogenesis inhibitor beta-cyclodextrin tetradecasulfate inhibits ecto-protein kinase activity. 128 48


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