Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.16 (calcineurin)
 17,112 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Preparations of the "induced protein" which appears in the rat uterus within 40 min of estradiol administration have recently been reported to contain phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) activity. We found that these two proteins distribute differently on ammonium sulfate fractionation of uterine cytosol. Preparative cellulose acetate electrophoresis afforded complete (greater than 99.9%) separation of phosphoprotein phosphatase activity from the induced protein. The specific activity of phosphoprotein phosphatase in uterine cytosol was unchanged 1, 4, 12, or 24 hr after estradiol administration. These results are incompatible with the view that the induced protein mediates estrogen action by virtue of an inherent phosphoprotein phosphatase activity.
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PMID:Separation of "estrogen-induced" protein from phosphoprotein phosphatase activity of immature rat uterus. 17 Jun 9

Partially purified rabbit skeletal muscle phosphorylase phosphatase (EC 3.1.3.17; phosphoprotein phosphohydrolase) was inactivated when it was incubated with exogenous cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase), cyclic AMP, and ATP-Mg. Subsequent separation of the phosphatase by acrylamide gel electrophoresis or sucrose density centrifugation resulted in reactivation of the enzyme. The phosphatase decreased in molecular weight from approximately 70,000 to 52,000, and a phosphorylated inhibitor with molecular weight of 26,000 was found. Reactivation of phosphatase also occurred when it was incubated with MnCl2 or trypsin. The inhibitor was effective at less than 10(-8) M and was relatively heat stable. Its activity was destroyed by tryptic digestion and by dephosphorylation by a Mn-stimulated phosphatase. These observations support the possibility that phosphorylase phosphatase activity is controlled by cyclic AMP-dependent protein kinase and a Mn-stimulated phosphatase by a reaction involving phosphorylation and dephosphorylation of a protein phosphatase inhibitor.
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PMID:Inactivation of rabbit muscle phosphorylase phosphatase by cyclic AMP-dependent kinas. 17 49

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.
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PMID:Adenosine 3',5'-monophosphate, the myocardial cell membrane, and calcium. 17 10

1. Troponin I isolated from fresh cardiac muscle by affinity chromatography contains about 1.9 mol of covalently bound phosphate/mol. Similar preparations of white-skeletal-muscle troponin I contain about 0.5 mol of phosphate/mol. 2. A 3':5'-cyclic AMP-dependent protein kinase and a protein phosphatase are associated with troponin isolated from cardiac muscle. 3. Bovine cardiac 3':5'-cyclic AMP-dependent protein kinase catalyses the phosphorylation of cardiac troponin I 30 times faster than white-skeletal-muscle troponin I. 4. Troponin I is the only component of cardiac troponin phosphorylated at a significant rate by the endogenous or a bovine cardiac 3':5'-cyclic AMP-dependent protein kinase. 5. Phosphorylase kinase catalyses the phosphorylation of cardiac troponin I at similar or slightly faster rates than white-skeletal-muscle troponin I. 6. Troponin C inhibits the phosphorylation of cardiac and skeletal troponin I catalysed by phosphorylase kinase and the phosphorylation of white skeletal troponin I catalysed by 3':5'-cyclic AMP-dependent protein kinase; the phosphorylation of cardiac troponin I catalysed by the latter enzyme is not inhibited.
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PMID:The phosphorylation of troponin I from cardiac muscle. 17 90

The distribution of phosphoprotein phosphatase (PPPase) and estrogen-induced protein (IP) from 19- to 20-day-old rat uteri before and after fractionation of uterine cytosol, by ammonium sulfate, and by preparative cellulose acetate gel electrophoresis was studied. There was a lack of significant difference between the specific activity of PPPase or its electrophoretic mobility in control extracts and those of extracts made 1 hour after injection of the rats with 5 mcg estradiol-17beta. Most of the recovered PPPase activity appeared in the fraction precipitating between 0-50% saturation with ammonium sulfate. Most of the IP is found at 50-80% saturation, and less than 10% of the PPPase activity. A single peak of PPPase activity was shown at a mobility of .5 relative to bovine serum albumin with electrophoresis of the 50-80% ammonium sulfate fraction. A peak of IP with mobility of 1.2 was also shown. ''The results are incompatible with the view that IP mediates estrogen action by virtue of its PPPase activity.''
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PMID:Proceedings: Separation of the "estrogen-induced protein" from phosphoprotein phosphatase activity of immature rat uteri. 17 73

Phosphoprotein phosphatase activity in the calf thyroid was found in various subcellular fractions. The relative amount in each fraction varied according to the substrate used: The 500g fraction had the highest specific activity when protamine was used, while the 5000g fraction was highest when histone was used. Triton X-100 tended to increase activity in all the particulate fractions, the greatest change being found in the 105,000g pellet. DEAE chromatography of the 105,000 g supernatant resolved at least three peaks of phosphoprotein phosphatase activity.
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PMID:Phosphoprotein phosphatase activity in the thyroid. 17 36

Diphosphonates are known to inhibit bone resorption in tissue culture and in experimental animals. This effect may be due to their ability to inhibit the dissolution of hydroxyapatite crystals, but other mechanisms may be important. Since lysosomal enzymes have implicated in the process of bone resorption, we have examined the effect of several phosphonates and of a polyphosphate (P20,2) on lysosomal hydrolases derived from rat liver and rat bone. Dichloromethylene diphosphonate strongly inhibited acid beta-glycerophosphatase (EC 3.1.3.2) and acid p-nitrophenyl phosphatase (EC 3.1.3.2) and to a lesser degree (in descending order) acid pyrophosphatase (EC 3.1.3.-), arylsulfatase A (EC 3.1.6.1), deoxyribonuclease II(EC 3.1.4.6) and phosphoprotein phosphatase (EC 3.1.3.16) of rat liver. Inhibition of acid p-nitrophenyl phosphatase and arylsulfatase A was competitive. Ethane-1-hydroxy-1, 1-diphosphonate did not inhibit any of these enzymes, except at high concentrations. Neither dichloromethylene diphosphonate nor ethane-1-hydroxy-1, 1-diphosphonate had any effect on beta-glucuronidase (EC 3.2.1.31), arylesterase (EC 3.1.1.2) and cathepsin D (EC 3.4.23.5). Of several other phosphonates tested only undec-10-ene-1-hydroxy-1, 1-diphosphonic acid inhibited acid p-nitrophenyl phosphatase strongly, the polyphosphate (P20, I) had little effect. Acid p-nitrophenyl phosphatase in rat calvaria extract behaved in the same way as the liver enzyme and was also strongly inhibited by dichloromethylene diphosphonate, but not by ethane-1-hydroxy-1, 1-diphosphonate. It is suggested that the inhibition of bone resorption by dichloromethylene diphosphonate might be due in part to a direct effect of this diphosphonate on lysosomal hydrolases.
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PMID:The effect of several diphosphonates on acid phosphohydrolases and other lysosomal enzymes. 17 70

The present study demonstrated the presence within the myocardium of phosphoprotein phosphatase activity which can account for dephosphorylation of a 22,000 dalton phosphoprotein of cardiac sarcoplasmic reticulum that has been associated with the stimulatory effects of adenosine 3':5'-monophosphate (cyclic AMP)-dependent protein kinase on calcium transport (Tada, M., Kirchberger, M. A., and Katz, A. M. (1975) J. Biol. Chem. 250:2640-2647). Dog cardiac microsomes, consisting mainly of fragmented sarcomplasmic reticulum, were phosphorylated by incubation with cyclic AMP-dependent protein kinase and [gamma-32P]ATP, and subsequently washed with trichloroacetic acid or buffered KCl. Phosphorylated microsomes contained approximately 1 nmole of 32P bound per mg of microsomal protein, 32P labeling occurring almost exclusively at the 22,000 dalton component. Soluble phosphoprotein phosphatases, isolated from the cytosol, catalyzed dephosphorylation of 32P-labeled microsomes. The existence of a phosphoprotein phosphatase that is associated with the microsomes was demonstrated by the ability of the microsomes to dephosphorylate 32P-histone. This membrane-associated phosphatase activity can also account for a rapid decrease in the amount of 32P-labeling of the 22,000 dalton protein. The dephosphorylation of the phosphorylated 22,000 dalton protein by phosphoprotein phosphatase satisfies an important requirement for the phosphorylation of the 22,000 dalton protein to serve a physiological role, namely, its reversibility.
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PMID:Phosphoprotein phosphatase-catalyzed dephosphorylation of the 22,000 dalton phosphoprotein of cardiac sarcoplasmic reticulum. 17 94

A peptide containing the four closely grouped phosphoseryl residues present in beta-casein has been enzymatically dephosphorylated with bovine spleen phosphoprotein phosphatase (EC 3.1.3.16). The course of the dephosphorylation reaction has been followed by cellulose acetate electrophoresis and the amount of partially phosphorylated peptides present at each stage quantified by the same method. The phosphate groups are shown to be removed in a sequential manner and the rate constants for each stage of the dephosphorylation have been computed from the data obtained. The rate constants indicate that interaction in the intact peptide results in an enhancement of the activity of the phosphoseryl cluster.
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PMID:A kinetic analysis of the dephosphorylation, by bovine spleen phosphoprotein phosphatase (EC 3.1.3.16) of a phosphopeptide derived from beta-casein. 18 Oct 85

1. Various proteins isolated from bovine tracheal smooth muscle were examined as phosphate acceptor substrates for a cyclic AMP-dependent protein kinase isolated from the same tissue. A fraction prepared in a manner similar to that of skeletal muscle troponin was the best substrate of the presumptive contractile proteins isolate. Actomyosin and tropomyosin were relatively poor substrates. 2. An assay was developed for the rapid detection in a large number of samples of the muscle specific substrate for the protein kinase on which we reported previously. 3. Using this assay, the muscle specific substrate found in bovine tracheal smooth muscle was partially purified resulting in a preparation which when resolved by polyacrylamide gel electrophoresis showed a single peak of 32P incorporated, and which could be further characterized. 4. Our findings suggest that the substrate contains a protein subunit of molecular weight 19 000, which can be phosphorylated at serine and threonine residues, in the presence of cyclic AMP and protein kinase. The phosphate is in a covalent ester linkage with these residues. 5. A phosphoprotein phosphatase was isolated from the bovine tracheal smooth muscle. 6. Bovine tracheal smooth muscle contains cyclic AMP dependent protein kinase and phosphoprotein phospahatase activity as well as the muscle specific substrate, suggesting that these elements may be part of a mechanism which regulates smooth muscle tone.
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PMID:Cyclic AMP-stimulated phosphorylation of bovine tracheal smooth muscle contractile and non-contractile proteins. 18 31


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