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

The inhibition of cell replication in two human carcinoma cell lines by various cyclic AMP analogs was explored. In all instances, the addition of the cyclic nucleotide phosphodiesterase inhibitor 1-methyl-3-isoburylxanthine resulted in synergistic growth inhibition by the analogs. A correlation was found between an analog's ability to inhibit growth and its ability to activate protein kinase. A differential effect of the breakdown product 8-bromo-AMP (8-BrAMP) on cell replication in the two cell lines was observed; i.e., one cell type was extremely sensitive to inhibition by 8-BrAMP and the growth inhibition could not be reversed by uridine, whereas the other cell type was less sensitive to 8-BrAMP and the growth inhibition was significantly reversed by uridine.
...
PMID:Differential growth inhibition in two human carcinoma cell lines by cyclic adenosine 5'-monophosphate analogs. 9 Jan 51

A regulatory role for adenosine 3',5'-monophosphate (cyclic AMP) in the production of the renal hormone rythropoietin following erythropoietic stimulation with cobaltous chloride hexahydrate is proposed. Studies in rates reveal a temporal relationship between renal cyclic AMP levels and plasma titers of erythropoietin. In addition, cobalt increases the activity of an erythropoietin-generating enzyme (renal erythropoietic factor) with maximal enzyme activity occurring after the rise in cyclic AMP levels but before the increase in erythropoietin titers. This increase in renal cyclic AMP is localized to the renal cortex. Cobalt stimulates renal cortical adenylate cyclase but has no effect on renal cyclic nucleotide phosphodiesterase. The addition of cyclic AMP (3 time 10-6 M) and a partially purified cyclic AMP-dependent protein kinase from rat kidney to an inactive preparation of renal erythropoietic factor increases the ability of renal erythropoietic factor to generate erythropoietin. Data from the polycythemic mouse assay, a bioassay used to quantitate erythropoietic activity of test substances, indicate that dibutyryl cyclic AMP is erythropoietically active with respect to its ability to increase radioactive-labelled iron (59Fe) incorporation into heme of newly formed red blood cells. Theophylline, which by itself is erythropoietically inactive, potentiated the erythropoietic effect of cobalt in polycythemic mice. These results suggest that cyclic AMP plays a significant role in the renal production of erythropoietin following cobalt administration. It is postulated that cobalt stimulates renal cortical adenyoate cyclase, thus increasing renal cyclic AMP levels. Cyclic AMP then activates a protein kinase which subsequently stimulates renal erythropoietic factor to generate erythropoietin. A similar cyclic AMP mechanism may be operative after erythropoietic stimulation by exposure to hypoxia or prostaglandin treatment.
...
PMID:The role of renal adenosine 3',5'-monophosphate in the control of erythropoietin production. 16 77

A number of 2-substituted cyclic nucleotide derivatives were synthesized and investigated as activators of cAMP-dependent protein kinase and as substrates for and inhibitors of cAMP phosphodiesterase. Ring closure of 5-amino-1-beta-D-ribofuranosylimidazol-4-carboxamide cyclic 3',5'-phosphate (1) with various aldehydes according to a new procedure (Meyer, R. B., Jr., Shuman, D.A., and Robins, R. K. (1974), J. Am. Chem. Soc. 96, 4962) gave new derivatives of adenosine cyclic 3',5'-phosphate with the following 2-substituents: n-propyl, n-hexl, n-octyl, n-decyl, styryl, o-methoxyphenyl, and 2-thienyl. Alkylation of 2-mercaptoadenosine cyclic 3',5'-phosphate (20, Meyer et al., 1974) gave new cAMP derivatives with the following 2-substituent: ethylthio, n-propylthio, isopropylthio, allylthio, n-decylthio, and benzylthio. Deamination of 2-methyl-,2-n-butyl-, and 2-ethylthioadenosine cyclic 3',5'-phosphate. Using multiple regression analysis, a striking relationship was found between the relative potency of the compounds as activators of bovine brain cAMP-dependent protein kinase and parameters describing the hydrophobic, steric, and electronic character of the substituents on these compounds. All compounds were substrates for a cyclic nucleotide phosphodiesterase preparation from rabbit kidney. Additionally, the compounds were as a group, good inhibitors of the hydrolysis of cAMP by phosphodiesterase preparations from rabbit lung, beef heart, and dog heart.
...
PMID:2-substituted derivatives of adenosine and inosine cyclic 3',5'-phosphate. Synthesis, enzymic activity, and analysis of the structural requirements of the binding locale of the 2-substituent on bovine brain protein kinase. 16 24

Catecholamine-sensitive adenylate cyclase, cyclic nucleotide phosphodiesterase, adenosine 3', 5'-monophosphate (cyclic AMP)-dependent protein kinase, kinase substrate, and phosphoprotein phosphatase have variously been reported to be present in preparations of myocardial cellular membranes that function in the movement of Ca2+ in and out of the cell and in intracellular Ca2+ translocations, indicating that these membranees possess the equipment for the formation and destruction of cyclic Amp as well as for the initiation, effectuation, and termination of a possible membrane action of the nucleotide. It has also been observed that phosphorylation of seryl residues of protein in sarcolemma- and sarcotubule-rich myocardial subcellular fractions by cyclic AMP activated intrinsic and extrinsic protein kinases confers upon these membran structures an enhanced ability to bind or take up Ca2+ and that dibutyryl cyclic AMP, like adrenaline, produces in intact cardiac muscle simultaneous increases in contractile force and in the uptake of extracellular Ca2+. These findings are suggestive of a second messenger role of cyclic AMP in the beta-adrenoreceptor-mediated actions of catecholamines on myocardial contractile force and relaxation, in which Ca2+ would serve as a third messenger and be subject, respectively, to more effective removal from its binding sites on troponin. An alternative interpretation regards Ca2+ and cyclic AMP as interdependent twin second messengers in the catecholamine-induced inotropism. Since the physiological meaning of the reported effects of cyclic AMP on isolated myocardial membrane preparations is far from established an instances of a dissociation between the effects of catecholamines on myocardial contractile force and cyclic AMP levels have been observed, there is still room for hypotheses that relegate cyclic AMP to a nonobligatory, at most, supportive role in the action of the catecholamines on cardiac contraction.
...
PMID:Adenosine 3',5'-monophosphate, the myocardial cell membrane, and calcium. 17 10

Ovine growth hormone (1 mug/ml) antagonized the lipolytic action of epinephrine (0.25 mug/ml) in segments of adipose tissue obtained from hypophysectomized rats, but a lag period of about 10 min was required. When added simultaneously with epinephrine, growth hormone neither reduced the maximal accumulation of cyclic AMP which occurred at 3 min nor accelerated the return to basal levels. Only when tissues were exposed to epinephrine 15 min after preincubation with growth hormone was cyclic AMP accumulation compromised. Growth hormone also produced a delayed increase of about 20% in the activity of a low Km cyclic nucleotide phosphodiesterase, which might have contributed to the decrease in cyclic AMP accumulation. The increase in phosphodiesterase activity probably did not account for the antilipolytic effect, however, since antilipolysis was evident before the increase in phosphodiesterase activity could be detected. The antilipolytic effects of growth hormone similarly could not be attributed to the decrease in cyclic AMP concentrations, for when added simultaneously with epinephrine the antilipolytic effects did not occur until after the evanescent changes in cyclic AMP had passed. Growth hormone added simultaneously with epinephrine or 30 min later significantly decreased the activity of protein kinase assayed in the absence of exogenous cyclic AMP, but did not change total protein kinase activity as measured in the presence of a saturating concentration of cyclic AMP. This effect of growth hormone was evident as early as 3 min after addition of the hormone and may at least partially account for the antilipolytic effect.
...
PMID:Studies on the mechanism of the antilipolytic effects of growth hormone. 18 54

1.3':5'-Cyclic AMP was extensively purified from Kalanchoe daigremontiana and Agave americana by neutral alumina and anion- and cation-exchange column chromatography. Inclusion of 3':5'-cyclic [8-3H]AMP from the point of tissue extraction permitted calculation of yields. The purification procedure removed contaminating material that was shown to interfere with the 3':5'-cyclic AMP estimation and characterization procedures. 2. The partially purified 3':5'-cyclic AMP was quantified by means of a radiochemical saturation assay using an ox heart 3':5'-cyclic AMP-binding protein and by an assay involving activation of a mammalian protein kinase. 3. The plant 3':5'-cyclic AMP co-migrated with 3':5'-cyclic [8-3H]AMP on cellulose chromatography, poly(ethyleneimine)-cellulose chromatography and silica-gel t.l.c. developed with several solvent systems. 4. The plant 3':5'-cyclic AMP was degraded by ox heart 3':5'-cyclic nucleotide phosphodiesterase at the same rates as authentic 3':5'-cyclic AMP. 1-Methyl-3-isobutylxanthine (1 mM), a specific inhibitor of the 3':5'-cyclic nucleotide phosphodieterase, completely inhibited such degradation. 5. The concentrations of 3':5'-cyclic AMP satisfying the above criteria in Kalanchoe and Agave were 2-6 and 1 pmol/g fresh wt. respectively. Possible bacterial contribution to these analyses was estimated to be less than 0.002pmol/g fresh wt. Evidence for the occurrence of 3':5'-cyclic AMP in plants is discussed.
...
PMID:Adenosine 3':5'-cyclic monophosphate in higher plants: Isolation and characterization of adenosine 3':5'-cyclic monophosphate from Kalanchoe and Agave. 19 95

The recently discovered heat-stable inhibitor protein of the Ca2+-activated cyclic nucleotide phosphodiesterase (Sharma, R. K., Wirch, E. & Warg, J. H. (1978) J. Biol. Chem., in press) has been purified 238 214-fold from bovine brain extract using an affinity column of the modulator protein--Sepharose 4B conjugate. The purified sample appears to be homogeneous as judged by sodium dodecyl sulphate (SDS) gel electrophoresis. The protein band has a mobility corresponding to that of a polypeptide of molecular weight 68 000. Since the heat-stable inhibitor protein has a molecular weight of 70 000 under nondenaturing conditions, it suggests that it is a monomeric protein. The protein has no inhibitory activity toward the cAMP-dependent protein kinase or protein phosphatase. The purified sample has been tested for various enzyme activities which include ATPase, GTPase, cAMP phosphodiesterase, cGMP phosphodiesterase, 5'-nucleotidase, and protein kinase. None of these activities are exhibited by the purified sample.
...
PMID:Purification of the heat-stable inhibitor protein of the Ca2+-activated cyclic nucleotide phosphodiesterase by affinity chromatography. 20 31

An assay for cyclic AMP is described which takes advantage of the high affinity of the dissociated receptor moiety of cyclic AMP-dependent protein kinase I for the nucleotide. The kinase is kept dissociated by salt (800 mM-NaCl/30mM-EDTA). In the presence of a simply prepared heat-stable protein fraction the binding reagent is stable for the time needed to reach equilibrium of binding. A simple procedure [precipitation with poly-(ethylene glycol) followed by DEAE-cellulose chromatography] is described for the separation of protein kinase I from other binding proteins for cyclic AMP in rabbit skeletal muscle. The sensitivity, precision, reproducibility and specificity of the assay compared favourably with those of other cyclic AMP assays. The main advantage of the present assay is its resistance towards non-specific interference from a number of salts, tissue-culture media and substances found in crude tissue extracts. The reliability of cyclic AMP measurement directly in crude tissue extracts was ensured by removal of the assayable cyclic AMP with cyclic nucleotide phosphodiesterase digestion or adsorption with antibody against cyclic AMP, by comparison with measurement in tissue extracts purified by chromatography on QAE-Sephadex or sequentially on Dowex 50, and aluminium oxide as well as by dilution and recovery experiments.
...
PMID:Measurement of adenosine 3':5'-cyclic monophosphate by competitive binding to salt-dissociated protein kinase. 21 54

Analysis of membranes from a variety of tissues has revealed a widespread distribution of a protein phosphorylation system dependent on the presence of both Ca2+ and "calcium-dependent regulator" (CDR). This protein phosphorylation system has been studied in some detail in nervous tissue. Neuronal membranes contain a protein phosphorylation system that requires Ca2+ and a soluble heat-stable protein [Schulman, H. & Greengard, P. (1978) Nature (London) 271, 478--479]. This protein has been purified to homogeneity from bovine cerebral cortex, with use of an assay based on its ability to stimulate Ca2+-dependent protein phosphorylation in membranes. This protein kinase activator appears to be identical to CDR of cyclic nucleotide phosphodiesterase. Throughout its purification, this single entity was found to activate both Ca2+-dependent protein kinase and cyclic nucleotide phosphodiesterase. The kinase activator purified here and authentic CDR were equally effective in their ability to activate Ca2+-dependent protein kinase.
...
PMID:Ca2+-dependent protein phosphorylation system in membranes from various tissues, and its activation by "calcium-dependent regulator". 21 87

beta-Adrenergic stimulation induces serotonin N-acetyltransferase (SNAT) activity in the rat pineal gland. The magnitude and some of the characteristics of this response vary as a function of the gland's previous exposure to stimulation. A period of stimulation results in a subsensitive response to subsequent stimulation. A period without stimulation provides a supersensitive response to subsequent stimulation. Investigations concerned with the mechanisms regulating the rat pineal's sensitivity to beta-adrenergic stimulation are described. These have focused on the regulation of cyclic AMP metabolism. Several of the components involved in the induction of SNAT activity appear to participate in the regulation of sensitivity. These include the beta-adrenergic binding sites, the catecholamine-sensitive adenylate cyclase, the cyclic nucleotide phosphodiesterase, and the cyclic AMP-dependent protein kinase. Thus, the rat pineal's sensitivity to beta-adrenergic stimulation appears to be regulated at multiple sites. Other investigations have focused on the regulation of pineal cyclic GMP metabolism. Unlike cyclic AMP, the stimulation of cyclic GMP synthesis requires the presence of intact nerve endings and of extracellular calcium. Some of the characteristics of pineal cyclic GMP regulation are described.
...
PMID:Sensitivity and cyclic nucleotides in the rat pineal gland. 22 42


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

---