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:3.1.4.1 (phosphodiesterase)
18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The concentration of a calcium-binding protein modulator of 3':5'-cyclic-nucleotide phosphodiesterase (EC 3.1.4.17; 3':5'-cyclic-nucleotide 5'-nucleotidohydrolase) activity is increased in chicken embryo fibroblasts upon transformation by Rous sarcoma virus. This modulator protein from fibroblasts, which has roughly the same molecular size, charge, and functional properties as that isolated from chicken brain, comprises approximately 1.32% of the soluble protein in homogenates of fibroblasts infected and transformed by Rous sarcoma virus. In comparison, the modulator comprises approximately 0.30% of the soluble protein in homogenates of normal fibroblasts from confluent cultures and 0.36% of the soluble protein in homogenates of fibroblasts infected with a transformation-defective mutant of Rous sarcoma virus. Modulator levels in normal fibroblasts at subconfluent cell densities are 0.42-0.76% of the homogenate soluble protein, i.e., between that found in confluent normal fibroblasts and in fibroblasts transformed by Rous sarcoma virus. These observations suggest that the levels of the modulator protein are elevated under conditions in which chicken embryo fibroblasts are undergoing rapid growth and have decreased adenosine 3':5'-cyclic monophosphate levels.
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PMID:Calcium-dependent regulatory protein of cyclic nucleotide metabolism in normal and transformed chicken embryo fibroblasts. 18 6

3':5'-Cyclic-AMP phosphodiesterase (EC 3.1.4.17) and the activating factor of cyclic nucleotide phosphodiesterase were detected in cultured human cell lines from patients with lymphoblastic leukemia and retinoblastoma and in the Brown-Pearce (rabbit) carcinoma. The homogenate of lymphoblasts contained levels of the activating factor in excess of that required to produce maximal activation of the endogenous phosphodiesterase. The activating factor found in these malignant cells appears to be similar to the calcium-binding protein activator of bovine brain phosphodiesterase on the basis of the molecular weight obtained from gel filtration, electrophoretic patterns, calcium requirement for the activity, and the effect of calcium on the proteolysis. In addition, the tumor-derived activator was able to restore the activity of activator-deficient phosphodiesterase from the bovine brain.
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PMID:Cyclic nucleotide phosphodiesterase and protein activator in human cancer cell lines and Brown-Pearce carcinoma. 20 Jul 56

We have purified and partly characterized a calcium-binding protein from the unfertilized egg of the sea urchin Arbacia punctulata. This protein closely resembles the calcium-binding modulator protein of bovine brain in its molecular weight, electrophoretic mobility, amino acid analysis, and peptide map. It activates bovine brain phosphodiesterase in the presence of calcium but has no effect on the phosphodiesterase of the Arbacia egg. Densitometric scanning of acrylamide gels of arbacia egg homogenates shows the modulator protein to represent 0.1% of the total protein of the egg. At 10(-4) M free calcium, the protein binds four calcium ions per 17,000-dalton molecule. We have used a column of rabbit skeletal muscle troponin-I covalently coupled to Sepharose 4B as an affinity column to selectively purify the Arbacia egg calcium-binding protein. This column has also been used to purify bovine brain modulator protein and may prove of general use in isolating similar proteins from other sources. The technique may be particularly helpful when only small quantities of starting material are available.
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PMID:Calcium-binding modulator protein from the unfertilized egg of the sea urchin Arbacia punctulata. 21 82

The interactions of the antiestrogenic drug tamoxifen with the calcium-binding protein calmodulin have been studied by computerized molecular modeling methods. Sites in both the N and C domains of the protein have been established, with one in the C domain having the highest calculated enthalpy of binding. The residues involved in the sites have been detailed. Modeling studies are reported for six tamoxifen derivatives, and their calculated enthalpies of binding are compared with the ability of the analogues to inhibit calmodulin-dependent cyclic AMP phosphodiesterase (PDE) (Rowlands et al. Biochem, Pharmacol. 1990, 40, 283-289). The poor binding properties of the piperazino and C-methyl derivatives are correctly predicted, whereas the superior affinity of 4-iodotamoxifen is not fully explained by the model.
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PMID:A molecular modeling study of the interactions between the antiestrogen drug tamoxifen and several derivatives, and the calcium-binding protein calmodulin. 132 85

The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on Ca2+/calmodulin-dependent cyclic nucleotide (AMP) phosphodiesterase activity in rat liver cytosol was investigated. The addition of Ca2+ (50 microM) and calmodulin 160 U/ml in the enzyme reaction mixture caused a significant increase in cyclic AMP phosphodiesterase activity. This increase was inhibited by the presence of regucalcin (0.5-3.0 microM); the inhibitory effect was complete at 1.0 microM. Regucalcin (1.0 microM) did not have an appreciable effect on basal activity without Ca2+ and calmodulin. The inhibitory effect of regucalcin was still evident even at several fold higher concentrations of calmodulin (160-480 U/ml). However, regucalcin (1.0 microM) did not inhibit Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity in the presence of 100 and 200 microM Ca2+ added. Meanwhile, Cd2+ (25-100 microM)-induced decrease in Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity was not reversed by the presence of regucalcin (1.0 microM). The present results suggest that regucalcin can regulate Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity due to binding Ca2+ in liver cells.
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PMID:Inhibitory effect of calcium-binding protein regucalcin on Ca2+/calmodulin-dependent cyclic nucleotide phosphodiesterase activity in rat liver cytosol. 165 6

S100 protein is a calcium-binding protein composed of two subunits S100 alpha and S100 beta, which are expressed selectively by specific cell types. The distribution of S100 beta was examined among various tissues obtained at autopsy from 18 subjects with chronic lung disease and 10 control subjects. The presence of S100 beta in individual cell types was demonstrated by immunoperoxidase staining using polyclonal and monoclonal antibodies specific for S100 beta. In the 10 control subjects, positive staining was seen in a number of cell types that normally produce S100 alpha and S100 beta, (e.g., glial cells, melanocytes, chondrocytes) or only S100 beta, (e.g., Schwann cells). There was no staining of myocardial cells, skeletal muscle fibers, or kidney tubules, which normally produce S100 alpha but not S100 beta. In contrast, in the 18 subjects with chronic lung disease, all of the above cell types stained positively for S100 beta, showing that in these subjects cell types that ordinarily expressed only S100 alpha also expressed S100 beta. We suggest that the observed induction of S100 beta in these cell types seen in subjects with chronic lung disease was mediated by an elevation of cAMP levels secondary to bronchodilator therapy with beta-adrenergic agonists and phosphodiesterase inhibitors.
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PMID:Immunoreactivity of S100 beta in heart, skeletal muscle, and kidney in chronic lung disease: possible induction by cAMP. 166 55

Recent evidence proposes that the calcium-binding protein, calmodulin, plays a crucial role in the regulation or modulation of the calcium-dependent potassium conductance in Paramecium tetraurelia (Hinrichsen, R.D., Burgess-Cassler, A., Soltvedt, B.C., Hennessey, T. and Kung, C. (1986) Science 323, 503-506). We purified the calmodulins from both the wild type and pantophobiac A (a mutant lacking the above-mentioned conductance and whose phenotypic defect is traceable to its calmodulin) by hydrophobic interaction and immunoaffinity chromatographies, and examined them biochemically. In this paper we address the preliminary characterization of the two calmodulins and discuss the consequences of the genetic alteration. The differences described here are in their electrophoretic mobilities in polyacrylamide gel electrophoresis and in their binding characteristics to monoclonal antibodies raised against calmodulin from wild-type paramecia. Also, we present data which indicate a difference in the stimulation of the calmodulin-dependent enzyme bovine brain phosphodiesterase under certain conditions.
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PMID:Biochemical characterization of a genetically altered calmodulin in Paramecium. 243 25

Plasma membrane has been prepared from pea seedlings in the presence of [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA). Calmodulin has been detected in these plasma membrane preparations using calcium overlay techniques, immunoblots, quantitation with antibodies raised against spinach calmodulin, phosphodiesterase activation, mobility shift, and heat stability. EGTA-stable calmodulin represents 0.5-1% of the total plasma membrane protein, and it is the only detectable calcium-binding protein in plasma membrane isolated under these conditions. The anti-spinach calmodulin reacts only with the N-terminal region of spinach calmodulin representing residues 1-106. The positioning of EGTA-stable calmodulin in the plasma membrane has been probed with trypsin and anti-spinach calmodulin. The data suggest that the calmodulin N-terminal region representing residues 1-106 projects from the membrane and could be available for binding other proteins. Calcium-dependent calmodulin binding to the plasma membrane has also been detected. Calcium-dependent calmodulin-binding proteins have been characterized using calmodulin overlay methods. The exposure of calmodulin-binding domains of most of these proteins from the plasma membrane is further suggested by their reaction with azidoiodinated calmodulin.
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PMID:The location of calmodulin in the pea plasma membrane. 249 18

The calcium-binding protein, calmodulin, has been purified from Xenopus laevis oocytes. This 18,500-dalton protein, pl 4.3, has two high-affinity calcium-binding sites per mole protein having a dissociation constant of 2.8 x 10(-6) M. Full-grown Xenopus oocytes, arrested in late G2 of the meiotic cell cycle, resumed meiosis when microinjected with 60-80 ng (3-4 pmol) of calmodulin in the form of a calcium-calmodulin complex. The timing of the meiotic events in these recipient oocytes was the same as that normally induced by progesterone. Xenopus ovarian calmodulin stimulated bovine brain phosphodiesterase (PDE) 3- to 10-fold in a calcium-dependent manner, but it had no apparent effect on ovarian PDE activity. A calcium-calmodulin-dependent protein kinase has been isolated from Xenopus oocytes using a calmodulin-Sepharose 4B affinity column. The possible role for this kinase in regulating the G2-M transition in oocytes has been discussed.
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PMID:Calmodulin triggers the resumption of meiosis in amphibian oocytes. 626 65

Calmodulin, a calcium-binding protein with no known enzymatic activity but multiple, in vitro effector activities, has been purified to apparent homogeneity from the unicellular green alga Chlamydomonas reinhardtii and compared to calmodulin from vertebrates and higher plants. Chlamydomonas calmodulin was characterized in terms of electrophoretic mobility, amino acid composition, limited amino acid sequence analysis, immunoreactivity, and phosphodiesterase activation. Chlamydomonas calmodulin has two histidine residues similar to calmodulin from the protozoan Tetrahymena. However, unlike the protozoan calmodulin, only one of the histidinyl residues of Chlamydomonas calmodulin is found in the COOH-terminal third of the molecule. Chlamydomonas calmodulin lacks trimethyllysine but does have a lysine residue at the amino acid sequence position corresponding to the trimethyllysine residue in bovine brain and spinach calmodulins. The lack of this post-translational modification does not prevent Chlamydomonas calmodulin from quantitatively activating bovine brain phosphodiesterase. These studies also demonstrate that this unique calmodulin from a phylogenetically earlier eukaryote may be as similar to vertebrate calmodulin as it is to higher plant calmodulins, and suggest that Chlamydomonas calmodulin may more closely approximate the characteristics of a putative precursor of the calmodulin family than any calmodulin characterized to date.
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PMID:Isolation and characterization of calmodulin from the motile green alga Chlamydomonas reinhardtii. 632 90


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