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

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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)

A heat-and acid-stable protein inhibitor of phosphorylase phosphatase is present in a highly purified preparation of protein inhibitor of cyclic AMP-dependent protein kinase from rabbit skeletal muscle. Although these two inhibitors have strikingly similar properties to each other, such as sensitivity to trypsin and behavior on gel permeation chromatography, they can be separated by polyacrylamide disc gel electrophoresis. This indicates that the phosphatase-inhibitory and kinase-inhibitory activities reside with different protein species. The inhibition of both the enzymes is not altered by incubating the inhibitor preparation with a general phosphoprotein phosphatase, with phosvitin kinase, or with cyclic AMP-dependent protein kinase. Inhibition of phosphorylase phosphatase is of a non-competitive type supporting the idea that the phosphatase inhibitor is not an alternative substrate for the enzyme. Inhibition of phosphatase activity is selective in that it does no occur when phosphorylated histone or phosphorylated protamine are used as substrates.
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PMID:Protein inhibitors of phosphorylase phosphatase and cyclic AMP-dependent protein kinase from rabbit skeleta muscle. 19 98

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.
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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.
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PMID:Modified cyclic nucleotide systems in Morris hepatoma 3924A favoring expression of cyclic GMP effect. 20 Dec 99

Properties of the ATP-dependent calcium transport system of heart sarcolemma are presented. Calcium accumulation (with oxalate) in sarcolemma was increased due to cAMP-dependent protein kinase and phosphorylase b kinase. Protein kinase increased the Vmax of the sarcolemmal calcium accumulation without any detectable effect on the affinity for Ca2+. Both kinases failed to stimulate calcium binding. Protein kinase catalyzed phosphorylation of membrane proteins of molecular weights of 100,000, 25,000, and 14,000. Phosphorylase b kinase also catalyzed phosphorylation of these proteins. Protein kinase stimulated ATPase activity of sarcolemma. Sarcolemma contained endogenous protein kinase and protein phosphatase activities.
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PMID:Characteristics of heart sarcolemmal calcium transport system and effect of protein kinase on sarcolemmal calcium accumulation. 20 83

Similar time courses were obtained for decreases in the rate of calcium transport by cardiac sarcoplasmic reticulum vesicles previously phosphorylated by cAMP-dependent protein kinase and dephosphorylation of the 22,000-dalton phosphoprotein in these membranes. Dephosphorylation of the 22,000-dalton phosphoprotein can be attributed to a phosphoprotein phosphatase in the sarcoplasmic reticular membranes. This membrane-bound phosphoprotein phosphatase may play a role in the reversal of the relaxation-promoting effect of catecholamines on the heart.
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PMID:Phosphoprotein phosphatase-catalyzed dephosphorylation of the 22,000-dalton phosphoprotein of cardiac sarcoplasmic reticulum. 20 87

The effects of streptozotocin-induced diabetes and of insulin supplementation to diabetic rats on glycogen-metabolizing enzymes in liver were determined. The results were compared with those from control animals. The activities of glycogenolytic enzymes, i.e. phosphorylase (both a and b), phosphorylase kinase and protein kinase (in the presence or in the absence of cyclic AMP), were significantly decreased in the diabetic animals. The enzyme activities were restored to control values by insulin therapy. Glycogen synthase (I-form) activity, similarly decreased in the diabetic animals, was also restored to control values after the administration of insulin. The increase in glycogen synthase(I-form) activity after insulin treatment was associated with a concomitant increase in phosphoprotein phosphatase activity. The increase in phosphatase activity was due to (i) a change in the activity of the enzyme itself and (ii) a decrease in a heat stable protein inhibitor of the phosphatase activity.
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PMID:The effect of streptozotocin-induced diabetes and of insulin supplementation on glycogen metabolism in rat liver. 20 91

A phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) was partially purified from pig heart using as substrate H2B histone which had been phosphorylated at Ser-32 and Ser-36 by adenosine 3',5'-monophosphate-dependent protein kinase (EC 2.7.1.37). The enzyme had a molecular weight of approx. 250 000 and was converted to a smaller form with a molecular weight of approx. 30 000 upon treatment with ethanol. Phosphorylase alpha (EC 2.4.1.1) and phosphorylated H1 histone also served as substrates for both forms of the enzyme. The conversion of the large form of the enzyme to the small form decreased the phosphohistone phosphatase activity to 25-50% with a concomitant 7-fold increase in the phosphorylase alpha phosphatase activity. Ser-36 phosphate was removed 6- and 15-fold more rapidly than was Ser-32 phosphate by the large and small forms of the enzyme, respectively. Among Ser-36-containing tryptic phosphopeptides derived from phosphorylated H2B histone, Lys-Glu-Ser(P)-Tyr-Ser-Val-Tyr was the shortest phosphopeptide which was dephosphorylated at a significant reaction rate with the phosphoprotein phosphatase. The Km values for phosphorylated H2B histone and the tryptic phosphopeptide were 23.7 micron and 187.1 micron, respectively, with the large form, and 81.4 micron and 90.0 micron, respectively, with the small form of the enzyme.
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PMID:Comparison of two forms of pig heart phosphoprotein phosphatase. 20 53

Calcium transport by cardiac sarcoplasmic reticulum (SR) was compared in hyperthyroid (HT) and euthyroid (ET) rats. Both Ca2+ uptake (97 +/- 3.1 nmol/mg per min in HT vs. 63 +/- 2.9 nmol/mg per min in ET, P less than 0.01) and CA2+ -stimulated ATPase activity (61 +/- 4.1 vs. 37 +/- 1.6 nmol Pi/mg per min, P less than 0.01) were higher in the thyroxine-treated animals. These changes were accompanied by enhanced cyclic AMP-dependent phosphorylation of cardiac SR in hyperthyroid rats (180 +/- 4.3 pmol Pi/mg per min vs. 117 +/- 4.2 pmol Pi/mg per min, P less than 0.01). SDS-polyacrylamide gel electrophoresis of cardiac SR showed that phosphorylation of a 22,000-dalton protein (phospholamban) primarily accounted for the differences between the two groups. There was no difference in the rate of SR dephosphorylation by endogenous phosphoprotein phosphatase between HT and ET rats. Differences in cyclic AMP-dependent phosphorylation between the two groups were blunted in the presence of excess exogenous cyclic AMP-dependent protein kinase. These results suggest that increased levels or activity of endogenous cyclic AMP-dependent protein kinases may partially explain enhanced calcium transport by the cardiac SR of hyperthyroid animals.
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PMID:Enhanced phosphorylation of myocardial sarcoplasmic reticulum in experimental hyperthyroidism. 20 50

The role of adenosine 3',5'-monophosphate (cyclic AMP)-dependent membrane phosphorylation in the regulation of microsomal calcium transport in rat aortic smooth muscle was studied. Cyclic AMP-dependent protein kinase augmented the phosphorylation of serine residues in a microsomal protein component with a molecular weight of about 44,000 (determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and the majority of 32P incorporation was in serine residue(s). The phosphorylated protein had stability characteristics of a phosphoester. The phosphorylated substrate was not extracted from the trichloroacetic acid (TCA) precipitate with organic solvents or by suspension in hot TCA; and the demonstrated hydroxylamine insensitivity suggested that the substrate was not lipid or nucleic acid. Intrinsic phosphoprotein phosphatase cleaved the labeled phosphate from the cyclic AMP-stimulated microsomes in the first 5 min of incubation. Microsomes phosphorylated in the presence of 1 micron cyclic AMP or 1 micron cyclic AMP plus 0.1 mg/ml protein kinase exhibited enhanced calcium uptake. We suggest that reversible phosphorylation of microsomal membranes may play an important role in the regulation of aortic microsomal calcium transport by cyclic AMP.
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PMID:Role of cyclic AMP in rat aortic microsomal phosphorylation and calcium uptake. 20 57

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.
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PMID:Purification of the heat-stable inhibitor protein of the Ca2+-activated cyclic nucleotide phosphodiesterase by affinity chromatography. 20 31


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