Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.17 (CaMKII)
 4,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incorporation of phosphorus from [gamma-32P]ATP into protein was catalyzed by specific immunoprecipitates from avian sarcoma virus (ASV)-transformed avian and mammalian cells. This incorporation was observed only when antiserum from tumor-bearing rabbits able to specifically precipitate the ASV sarcoma gene product, p60src, was used to immunoprecipitate antigens from transformed cell lysates. Immunoprecipitates of extracts from normal cells or cells infected with a transformation-defective ASV mutant showed no activity in this assay, nor did any immune complexes formed with normal rabbit serum and any of the cell extracts tested. The expression of the protein kinase activity (ATP:protein phosphotransferase, EC 2.7.1.37) was growth temperature-dependent in cells infected with an ASV mutant temperature-sensitive for the transformation. These results on an enzymatic activity associated with the ASV transforming protein are discussed in terms of protein phosphorylation as a mechanism for viral transformation.
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PMID:Protein kinase activity associated with the avian sarcoma virus src gene product. 20 79

Guanosine 3':5'-monophosphate-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) has been isolated from silkworm pupal fat body (Bombyx mori) which is devoid of any adenosine 3':5'-monophosphate-dependent protein kinase. The enzyme displayed catalytic properties which were roughly similar to those described for adenosine 3':5'-monophosphate-dependent protein kinase. This similarity has been found in substrate specificity, optimal Mg2+ dependency, polyamines effects and the lack of dependency upon sulfhydryl compound for activation by cyclic GMP. Treatment of the enzyme with sulfhydryl reagents, N-ethylmaleimide or p-chloromercuribenzoic acid, inhibited the catalytic activity as well as the dissociation of the binding and catalytic activities as shown by means of sucrose-density gradient ultracentrifugation. In the presence of cyclic GMP or histone, the disulfide-linked structure did not dissociate into separate subunits nor did it migrate as the holoenzyme but sedimented as an intermediate form carrying both binding and catalytic activities.
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PMID:Evidence for a role of sulfhydryl groups in catalytic activity and subunit interaction of the cyclic GMP-dependent protein kinase from silkworm. 21 Aug 22

The ontogeny of two endogenous substrates for cyclic AMP-dependent protein kinase (ATP:protein phosphotransferase; EC 2.7.1.37) has been studied in rat and guinea pig cerebrum. These endogenous substrates, referred to as proteins Ia and Ib, have been shown in other studies to be specific to nervous tissue and to be enriched in the synaptic membrane and synaptic vesicle fractions of adult brain. In the present study, proteins Ia and Ib were shown to increase markedly during the time of major synaptogenesis in rat cerebrum and guinea pig cerebrum, in which the morphological development of synapses is predominantly postnatal and prenatal, respectively. Similar results were obtained either by measuring endogenous phosphorylation of proteins Ia and Ib in the synaptic membrane fraction or by measuring phosphorylation of extracted proteins Ia and Ib with added protein kinase.
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PMID:Ontogeny of synaptic phosphoproteins in brain. 21 13

A cyclic AMP-like substance has been isolated from higher plant tissues which can be quantitated with the use of a radioimmunoassay similar to that described by A. L. Steiner, D. M. Kipnis, R. Utiger, and C. Parker [(1969) Proc. Natl. Acad. Sci. USA 64, 367-373]. This compound has been extensively purified and is chromatographically distinct from authentic cyclic AMP. This cyclic AMP-like compound inhibited beef heart 3':5'-cyclic-nucleotide phosphodietsterase (3':5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17), with half-maximal inhibition occurring at a concentration of 7.6 X 10(-10) M cyclic AMP equivalents. The compound also inhibited cyclic AMP-dependent protein kinase (ATP:protein phosphotransferase; EC 2.7.1.37) from bovine heart, with half-maximal inhibition of mixed histone phosphorylation occurring at 8.0 X 10(-11) M cyclic AMP equivalents. Equipotent inhibition of phosphorylation and associated trace ATPase activity were observed with the purified catalytic subunit of cyclic AMP-dependent protein kinase from calf thymus with a synthetic heptapeptide as substrate. Moreover, steady-state kinetic analysis of this inhibition in the latter system showed it to be nonlinear and noncompetitive versus MgATP.
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PMID:Inhibition of mammalian protein kinase and phosphodiesterase activities by a cyclic AMP-like compound isolated from higher plants. 21 43

Chinese hamster ovary cells exhibit several characteristic morphological and physiological responses upon treatment with agents which increase the intracellular level of adenosine 3':5'-phosphate (cyclic AMP). To better understand the mechanism of these cyclic AMP-mediated responses, we separated two cyclic AMP-dependent protein kinases (ATP:protein phosphotransferase, EC 2.7.1.37) (protein kinase I and protein kinase II) from the cytosol of Chinese hamster ovary cells by DEAE-cellulose chromatography and studied their properties. Protein kinase I is eluted at a lower salt concentration than protein kinase II and is stimulable to 10 times its basal catalytic activity, while protein kinase II is stimulable only 2-fold. Both kinases are completely dissociated by cyclic AMP and inhibited by specific cyclic AMP-dependent protein kinase inhibitor. They have similar Km values for magnesium (approximately 1 mM), cyclic AMP (approximately 60 nM), and ATP (approximately 0.1 mM), and the dissociation constant (Kdis) for cyclic AMP (approximately 13 nM) is the same for both enzymes. However, they appear to have different substrate preferences and cyclic AMP-binding properties in that cyclic AMP bound to protein kinase II exchanges readily with free cyclic AMP, while that bound to protein kinase I is not exchangeable. The native enzymes have different sedimentation coefficients (6.4 S for protein kinase I and 4.8 S for protein kinase II), whereas those of the activated enzymes are the same (2.9--3.0 S). It appears that the two cyclic AMP-dependent protein kinases which differ from each other in their regulatory subunits may play different roles in the mediation of cyclic AMP action in Chinese hamster ovary cells.
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PMID:Characterization of two adenosine 3':5'-phosphate-dependent protein kinase species from Chinese hamster ovary cells. 21 11

The adenosine 3",5"-monophosphate (cAMP)-dependent ATPase (ATP phosphohydrolase, EC 3.6.1.3) activity of cAMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) from bovine heart is characterized. That the ATPase activity is intimately associated with the catalytic subunit of the enzyme is suggested by the following: (i) the similar dependences of ATPase and protein kinase activities on cAMP; (ii) the dissociation of ATPase activity from the holoenzyme on addition of cAMP and its co-elution with the catalytic subunit on gel filtration chromatography; (iii) the similarity of the relative effectiveness of divalent metal ions in ATPase and protein kinase catalysis; and (iv) the correspondence of kinetically determined Km(MgATP) and Ki(MgADP) values with thermodynamic dissociation constants determined by equilibrium dialysis. The hydrolysis of ATP is stimulated 10- to 20-fold by cAMP in the holoenzyme. The molar specific activity of the catalytic subunit ATPase is approximately 0.7 min-1 with Km(MgATP) = 5 muM. MgADP is a competitive inhibitor of the reaction with a Ki value of approximately muM. The order of the relative effectiveness of metal ions for both ATPase and peptide kinase activities is Mg2+ greater than Mn2+ greater than Ca2+. A possible interpretation of these observations is that the role that the metal ion plays is more directly manifested in bond-breaking than in bond-forming.
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PMID:Cyclic AMP-dependent ATPase activity of bovine heart protein kinase. 21 18

Sera from certain rabbits bearing Schmidt-Ruppin strain Rous sarcoma virus (RSV)-induced tumors precipitated p60(src) from chicken cells transformed by the homologous virus as well as by other strains [Prague strain RSV, Bryan high-titer strain RSV, and Bratislava 77 strain of avain sarcoma virus (ASV)], the molecular weights (M(r)s) ranging from 60,000 to 64,000. The p60(src) immunoprecipitated from cells transformed by each of these strains incorporated [gamma-(32)P]ATP into the M(r) 53,000 subunit of IgG, though with differing activities. No such protein kinase activity (ATP:protein phosphotransferase, EC 2.7.1.37) was observed when the following immunoprecipitates were used: from uninfected cells, from untransformed cells infected by Rous-associated virus, or from cells transformed by acute leukosis viruses, avian erythroblastosis virus, or myelocytoma virus 29. The kinase reaction had a pH optimum at pH 5.9 and an apparent K(m) for ATP of 4.9 +/- 2 muM, and was dependent on Mg(2+) (K(b) = 46 +/- 12 mM), for which Ca(2+) was no substitute. The kinase was cyclic AMP independent. In order to test whether the protein kinase reaction is directly catalyzed by p60(src), we compared the in vitro temperature sensitivities of the kinase activities from cells infected by transformation-temperature-sensitive mutant and parental wild-type virus. The first-order rate constant for the inactivation of the kinase from extracts of cells infected by the mutant virus was 2-fold greater than that from cells infected by wild-type virus. This result implicates the protein kinase as an enzymatic activity of the src gene product, the p60(src). Concomitant with the loss of the kinase activity by heat inactivation, p60(src) loses 60-70% of its phosphate content. The kinetics of dephosphorylation exactly parallel those for the inactivation of the kinase activity, suggesting that the p60(src) kinase is itself dependent on phosphorylation for its activity.
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PMID:Src Gene product from different strains of avian sarcoma virus: Kinetics and possible mechanism of heat inactivation of protein kinase activity from cells infected by transformation-defective, temperature-sensitive mutant and wild-type virus. 21 25

A series of synthetic peptide analogs of the cardiac troponin inhibitory subunit (TN-1) phosphorylation site sequence, Arg12-Pro-Ala-Pro-Ala-Val-Arg18-Arg19-Ser20-Asp21-Arg22-Ala, have been tested as substrates for the catalytic subunit of the cyclic AMP-dependent protein kinase (EC 2.7.1.37, ATP:protein phosphotransferase). As substrates, these peptides were generally inferior to the pyruvate kinase analog peptide Leu-Arg-Arg-Ala-Ser-Leu-Gly or its COOH-terminal amide analog. Replacing Arg-19 with alanine had only a minor effect on the kinetics of phosphorylation of the TN-1 peptide analog. In contrast, replacement of Arg-22 and Arg-18 with alanine resulted in marked enhancement and reduction of the Vmax, respectively. The results of this study have demonstrated that synthetic peptide analogs of the local phosphorylation site sequences of natural substrates may differ widely in their capacity to act as substrates for this protein kinase. In the case of the TN-1 peptide analogs, the contribution of the 4 arginine residues can be distinguished in terms of their influence on the kinetics of phosphorylation.
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PMID:Phosphorylation of synthetic peptide analogs of rabbit cardiac troponin inhibitory subunit by the cyclic AMP-dependent protein kinase. 21 49

Cyclic AMP-dependent protein kinases (EC 2.7.1.37; ATP:protein phosphotransferase) in the human diploid fibroblast WI-38 and an SV40-transformant WI-38-VA13-2RA (VA13) have been compared on the basis of their concentrations in cells, isoenzyme composition and susceptibility to hormonal activation. In high population density cultures, total soluble cyclic AMP-dependent kinase activities measured with histone were essentially the same in WI-38 and VA13. Two soluble protein kinase forms separated by chromatography on DEAE-cellulose were present in both cell lines. The concentration of cyclic AMP required for half-maximal activation of both enzyme forms was 10-30 nM. Overall kinase stimulation was greater for the Peak I enzymes. Kinase activation induced in the presence of 0.5 M KCl was more rapid and complete for the Peak I enzymes. Under conditions which elevated the concentration of cyclic AMP in WI-38 and VA13 cells the activities of the soluble histone kinases were increased. Incubation of the cells with either of 5.7 micronM prostaglandin E1 or 1 micronM isopropylnorepinephrine induced complete activation of the cyclic AMP-dependent histone kinases within 5 min and maintained the effect for 20 min. When intracellular cyclic AMP levels were raised by prostaglandin E1, activation of glycogen phosphorylase (assayed-AMP) suggested that this enzyme cascade involving cyclic AMP-dependent protein kinase(s) was intact and responsive in both cell lines.
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PMID:Adenosine 3',5'-monophosphate-dependent protein kinase(s) in diploid and SV40 transformed human fibroblasts. 21 99

In cell homogenates of Dictyostelium discoideum, strain AX-2, four major soluble protein kinases (ATP:protein phosphotransferase, EC 2.7.1.37) and one membrane-associated protein kinase activity were identified. The enzymes showed high affinity for casein. One of the enzymes was purified by affinity chromatography on casein-coated Sepharose. The soluble high molecular weight enzymes phosphorylated histones, whereas the low molecular weight enzymes did not. The same protein kinase species were present in vegetative and aggregation-competent cells. Their specific activity, however, changed during the development to aggregation competence. None of the enzymes was stimulated by cyclic AMP or cyclic GMP, regardless of their origin from vegetative or aggregation-competent cells.
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PMID:Protein kinases of Dictyostelium discoideum, strain AX-2. 22 Oct 22


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