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)

Endogenous protein kinase activity was detected in the outer plasma membrane of 373 and SV40 transformed 3T3 cells. When intact cells were incubated with [gamma-32P]ATP, there was a transfer of [32P]phosphate into an acid-insoluble product. The reaction was: (a) linear as a function of time (up to 30 min), (b) proportional to the number of cells present and (c) dependent on temperature and Mg2+ concentration. The acid-insoluble product was susceptible to pronase but not RNase or DNase. More specifically, phosphomonoester bonds to serine and threonine were identified. There was less than 3% hydrolysis of the [gamma-32P]ATP during the reaction; moreover, free [32P]phosphate failed to substitute for the ATP. The reaction product was located on the cell surface, as evidenced by the fact that it could be removed by mild trypsin treatment of intact 3T3 cells. Further evidence for the surface location of the kinase was shown by its activity in phosphorlating exogenous substrate, histone, and phosvitin. The level of phosphorylation increased by 2- to 4-fold prior to the start of S phase when quiescent 3T3 cells were stimulated to reinitiate growth by the addition of serum. The SV40 3T3 cells had from 5- to 10-fold more activity per cell than the quiescent 3T3 cells. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and radioautography show at least 25 phosphorylated proteins; the surface label pattern of 3T3 cells differs from that of SV40-transformed 3T3 cells.
J Biol Chem 1976 Dec 25
PMID:Endgoenous protein kinase in outer plasma membrane of cultured 3T3 cells. Nature of the membrane-bound substrate and effect of cell density, serum addition, and oncogenic transformation. 18 98

The effect of different doses of luteinizing hormone on activation of protein kinases, cyclic AMP and testosterone production was studied in purified rat testis Leydig-cell preparations in the presence of 3-isobutyl-1-methylxanthine (a phosphodiesterase inhibitor). In addition, the nature of the protein kinases present in these cells and other tissues was investigated. The following results were obtained. 1. With all the amounts of luteinizing hormone used (0.1-1000 ng/ml), both activation of protein kinase and stimulation of testosterone production were demonstrated. With the lowest amount of luteinizing hormone (0.1 ng/ml), an 8.4+/-0.9% (S.E.M.,n=6) stimulation of protein kinase activation occurred, increasing to 100% with 1000 ng/ml, compared with 3.2+/-1.0%(S.E.M.,n=7) and 100% stimulation of testosterone production with 0.1 and 100 ng/ml respectively. 2. With amounts of luteinizing hormone up to 1 ng/ml (which gave half-maximal stimulation of testosterone production) no detectable increases in net cyclic AMP production were obtained. With higher amounts of luteinizing hormone, cyclic AMP production increased, but maximal production was not reached with 1000 ng/ml. 3. Two isoenzymic forms of protein kinase were present in Leydig cells and seminiferous tubules; type I was eluted with 0.075 M-and type II with 0.22-0.25 m-NaCl from DEAE-cellulose columns. 4. The protein kinase activity was not affected by the presence of erythrocytes in the Leydig-cell preparation, but varied depending on the type of histone used as substrate (histone F2b greater than mixed greater than histone F1).
Biochem J 1976 Dec 15
PMID:Correlation of protein kinase activation and testosterone production after stimulation of Leydig cells with luteinizing hormone. 18 52

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.
Biochim Biophys Acta 1977 Dec 14
PMID:Cytoplasmic and nuclear protein kinases during the cell cycle. 20 Feb 70

The degree of cyclic AMP-dependent protein kinase activation in response to dibutyryl cyclic AMP and norepinephrine was determined in samples of rat heart obtained from hyperthyroid and euthyroid animals. The data indicate that thyroid hormone-induced supersensitivity to the metabolic effects of the catecholamines cannot be explained on the basis of a change in activity of supernatant protein kinase.
Res Commun Chem Pathol Pharmacol 1977 Dec
PMID:Cyclic AMP-dependent protein kinase activation in hearts from euthyroid and hyperthyroid rats. 20 Sep 95

1. Calcium transport into microsomal vesicles of respiratory (tracheal) smooth muscle was characterized. This calcium transport was ATP dependent and stimulated by the presence of the oxalate ion. The magnitude of transport was similar to that reported for microsomes from other types of smooth muscle. 2. Bovine and rabbit, heavy and light microsomes were isolated from respiratory (tracheal) and vascular (aortic) smooth muscle. Preincubation of these vesicles with cyclic AMP and protein kinase did not alter the transport of calcium into the vesicles. There uas no evidence of phosphate incorporation into microsomal membrane proteins. Similar results were obtained if phosphorylase b kinase replaced the combination of cyclic AMP and protein kinase during the preincubation. 3. The phosphoprotein phosphatase activity of cardiac sarcoplasmic reticulum and smooth muscle microsomes was determined. The activity of this enzyme was found to be several-fold less in the cardiac sarcoplasmic reticulum than in various smooth muscle microsome preparations.
Biochim Biophys Acta 1977 Dec 22
PMID:Determination of calcium transport and phosphoprotein phosphatase activity in microsomes from respiratory and vascular smooth muscle. 20 Dec 93

Modifications in the cyclic nucleotide systems favoring the expression of cyclic GMP effects were found to occur in the transplanted fast-growing Morris hepatoma 3924A. These included: (a) a decreased level of cyclic GMP phosphodiesterase and an increased level of cyclic AMP phosphodiesterase; (b) a disproportionately increased level of cylic GMP-dependent protein kinase relative to that of cyclic AMP-dependent protein kinase; (c) a disproportionately increased level of stimulatory modulator of cyclic AMP-dependent protein kinase relative to that of inhibitory modulator of cyclic AMP-dependent protein kinase; and (d) an increased level of phosphoprotein phosphatase.
Biochim Biophys Acta 1977 Dec 22
PMID:Modified cyclic nucleotide systems in Morris hepatoma 3924A favoring expression of cyclic GMP effect. 20 Dec 99

A human skeletal actin.tropomyosin.troponin complex was phosphorylated in the presence of [gamma-32 P]ATP, Mg2+, adenosine 3':5'-monophosphate (cyclic AMP) and cyclic AMP-dependent protein kinase (protein kinase). Phosphorylation was not observed when the actin complex was incubated in the absence of protein kinase or 1 microM cyclic AMP. In the presence of 10(-7) M Ca2+ and protein kinase 0.1 mole of [32P]phosphate per 196 000 g of protein was incorporated. This was two-fold higher than the [32P]phosphate content of a rabbit skeletal actin complex but two-fold lower than that of a bovine cardiac actin complex. At high Ca2+, 5.10(-5) M, little change in the phosphorylation of a human skeletal actin complex occurred. Phosphoserine and phosphothreonine were identified in the [32P]phosphorylated actin complex. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate showed that 60% of the label was associated with the tropomyosin binding component of troponin. The inhibitory component of troponin contained 16% of the bound [32P]phosphate. Increasing the Ca2+ concentration did not significantly decrease the [32P]phosphate content of the phosphorylated proteins in the actin complex. No change in the distribution of phosphoserine or phosphothreonine was observed. Half maximal calcium activation of the ATPase activity of reconstitute human skeletal actomyosin made with the [32P] phosphorylated human skeletal actin complex was the same as a reconstituted actomyosin made with an actin complex incubated in the absence of protein kinase at low or high Ca2+.
Biochim Biophys Acta 1977 Dec 23
PMID:Phosphorylation of an actin.tropomyosin.troponin complex from human skeletal muscle. 20 9

The activities of adenosine 3':5'-monophosphate (cyclic AMP)-dependent protein kinase may be partially controlled by a ubiquitous acidic heat-stable protein which inhibits the phosphotransferase reaction by interaction with the catalytic subunit of protein kinase (Walsh, D.A. et al. (1971), J. Biol. Chem. 246, 1977-1985). Since reported purification of this inhibitor involved subjecting tissue extracts to denaturing conditions, its existence under physiological conditions remained uncertain. A protein inhibitor, molecular weight 22,500, has been isolated from bovine myocardium by methods that do not include exposure to extreme heat or acid precipitation. The activity of this acidic protein is destroyed by exposure to trypsin and is unaffected by treatment with neuraminidase, RNAse or DNAse.
J Cyclic Nucleotide Res 1977 Dec
PMID:Purification of a protein inhibitor of adenosine 3':5'-monophosphate-dependent protein kinase from bovine myocardium by a non-denaturing procedure. 20 14

The mechanism of inhibition of adenosine 3':5'-monophosphate (cyclic AMP)-dependent protein kinase was studied using a protein inhibitor isolated by a non-denaturing procedure from bovine heart. This protein inhibitor interacts with the catalytic subunit of protein kinase and binds to some substrates of the kinase. Protein kinase activity can also be inhibited by polyanions which, like the protein inhibitor, bind to basic substrates but do not bind to the catalytic subunit of protein kinase. Peptides such as L-lysyl-L-tyrosyl-L-threonine that resemble the phosphate accepting site of protein kinase substrates competitively inhibit phosphorylation of histone. Protein kinase activity can thus be inhibited in vitro by interaction of the protein inhibitor with substrates, and/or the catalytic subunit of the kinase, by competition of substrate analogs with "natural" substrates and by direct interaction of polyanions with basic protein substrates for the phosphotransferase reaction.
J Cyclic Nucleotide Res 1977 Dec
PMID:Inhibition of adenosine 3':5'-monophosphate-dependent protein kinase: comparison of a protein inhibitor with polyanions and substrate analogs. 20 15

1. A simple purification procedure for microtubule proteins is described, which involves a single assembly step in vitro in the absence of glycerol, followed by centrifugation through sucrose. 2. The preparation contains 80% tubulin (mol.wt. 54000), 15-20% of a 280000-mol.wt. protein and several other minor components of intermediate molecular weight after polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate and 2-mercaptoethanol. 3. In the presence of [gamma-32P]ATP, [32P]phosphate was incorporated into the 280000-mol.wt. component reaching half-maximal incorporation at 1-2 min, but no phosphorylation of tubulin was detected. Cyclic AMP (Km 0.8 micrometer) increased both the initial rate and the extent of incorporation of [32P]phosphate into this component. 4. About half of the endogenous protein kinase activity did not require cyclic AMP and was not inhibited by a heat-stable inhibitor protein from muscle. The remainder of the activity was cyclic AMP-dependent and sensitive to the inhibitor protein. A regulatory subunit was not dissociable from microtubules assembled in vitro in the presence of saturating concentrations of cyclic AMP. 5. The endogenous substrate and the endogenous protein kinase activity could be partially resolved chromatography on phosphocellulose. 6. The data show that cyclic AMP can moduate the activity of an endogenous protein kinase(s) with unusual properties and which phosphorylates a prominent microtubule-associated protein.
Biochem J 1977 Dec 15
PMID:Phosphorylation of pig brain microtubule proteins. General properties and partial characterization of endogenous substrate and cyclic AMP-dependent protein kinase. 20 90


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