Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Measurements of cyclic phosphodiesterase, or of beta-galactosidase in the case of cpdB'-'lacZ fusions, indicate that cpdB expression in both Escherichia coli and Salmonella typhimurium is modulated by carbon source availability, consistent with previous observations in Salmonella. Nucleotide sequence analysis and transcription mapping of both cpdB genes have revealed, in their 5' flanking regions, sequences with good similarity to consensus -10 and -35 regions and cyclic AMP-cyclic AMP receptor protein (cAMP-CRP) binding sites. Furthermore, they are strongly conserved in both organisms. Deletion analysis of an E. coli cpdB'-'lacZ fusion supports the identification of these elements, and a role for the cAMP-CRP binding site in modulating constitutive cyclic phosphodiesterase expression.
Mol Gen Genet 1990 Jun
PMID:Transcription and regulation of the cpdB gene in Escherichia coli K12 and Salmonella typhimurium LT2: evidence for modulation of constitutive promoters by cyclic AMP-CRP complex. 217 62

Three linear DNA plasmids were found in isolate RI-64 of anastomosis group 4 (AG-4) of Rhizoctonia solani. These plasmids, designated pRS64-1, -2, and -3, possessed the same size of 2.7 kb. Restriction mapping and Southern hybridization analysis of pRS64-1, -2, and -3 revealed the presence of homologous regions at both termini. The plasmid DNAs were resistant to both 3'-exonuclease and 5'-exonuclease even after treatment with proteinase K or alkali. The length of both terminal fragments that were generated by restriction endonuclease digestion was doubled under the denaturation condition, indicating that the linear plasmid DNAs have hairpin loops at both termini. Southern blotting analysis of total DNA showed the presence of two types of dimeric forms of pRS64 DNA. One is a head-to-head dimer and the other is a tail-to-tail dimer. The role of these unique DNA structures in replication of the plasmids is discussed.
Mol Gen Genet 1990 Jan
PMID:Linear plasmid DNAs of the plant pathogenic fungus Rhizoctonia solani with unique terminal structures. 232 20

The hormonal control of proline transport in pyloric ceca was studied in regard to the effects of cortisol, growth hormone (GH), epinephrine, and 3-isobutyl-1-methylxanthine (IBMX). Cortisol pellets implanted in yearling freshwater (FW) salmon for 2 weeks elevated plasma cortisol levels six times above that of control fish. The maximal influx (Jmax) and the half-saturation constant (Kt) of proline influx were twofold greater in cortisol-treated fish than the values in controls; the apparent passive permeability coefficient (Pa) was significantly reduced in the former group. FW salmon implanted with GH for 2 weeks showed increased body weight gain and a higher Jmax of proline influx compared with that of control fish. GH treatment resulted in a higher Pa of proline influx as well as in a 30% increase in area-specific intestinal dry weight. Thus, GH and cortisol may play a regulatory role in intestinal amino acid absorption during salmon development. The in vitro effects of epinephrine and the phosphodiesterase inhibitor, IBMX, on short-circuit current (Isc) and proline influx in salmon intestine were examined. Epinephrine (10(-6) M) caused a rapid increase in negative Isc (mucosa, ground). Pyloric ceca preincubated with epinephrine for 30 min showed reduced total proline influx compared with influx in paired control tissues. Epinephrine increased and IBMX decreased the Kt of proline influx; IBMX also reduced Jmax. The possible interaction between the effects of epinephrine and IBMX on ion transport and Na+-coupled proline influx are discussed.
Gen Comp Endocrinol 1985 Sep
PMID:Hormonal effects on L-proline transport in coho salmon (Oncorhynchus kisutch) intestine. 241 38

The possible roles of follicular cyclooxygenase and cAMP in the control of in vitro spontaneous brook trout (Salvelinus fontinalis) ovulation were investigated. Brook trout oocytes that had undergone germinal vesicle breakdown and follicular separation in vivo, were incubated in vitro in the presence of indomethacin. At 3 or 30 microM, indomethacin significantly reduced the levels of PGF and PGE (measured by radioimmunoassay) in the incubation medium but did not inhibit spontaneous ovulation in vitro. Follicular cAMP levels were measured by a competitive protein binding assay, prior to and during spontaneous ovulation. cAMP levels were approximately 3.2 pmol/mg protein prior to incubation and did not fluctuate significantly from this value throughout the 24-hr incubation period. The phosphodiesterase inhibitor, 3-isobutyl-l-methyl-xanthine, significantly increased follicular cAMP levels at 1.0 and 0.1 mM. The combined results suggest that cyclooxygenase metabolites or a decrease in cAMP are not involved in the control of spontaneous brook trout ovulation in vitro. The in vitro effects of primaquine, a putative phospholipase mediator, were also investigated. At lower concentrations (0.1-0.5 mM), primaquine significantly enhanced ovulation above that observed in spontaneous controls. However, at 1.0 mM, primaquine inhibited spontaneous ovulation. Indomethacin at 3 or 30 microM did not block the stimulatory effect of primaquine observed at lower concentrations, indicating that cyclooxygenase metabolites are not involved in the stimulatory effect of primaquine on ovulation.
Gen Comp Endocrinol 1986 Jan
PMID:Investigations on the control of in vitro spontaneous brook trout (Salvelinus fontinalis) ovulation. 241 33

Glucagon increases the rate of glycogenolysis in in vitro cultures of hepatic tissue from the axolotl Ambystoma mexicanum. The hormone causes an increase in the concentration of cyclic AMP in the tissue which is followed by activation of glycogen phosphorylase and subsequent breakdown of glycogen and release of glucose from the tissue. Insulin counteracts the glycogenolytic effect of glucagon by inhibiting the increase in tissue cyclic AMP concentration brought about by glucagon. This inhibitory effect of insulin is not seen in the presence of the phosphodiesterase inhibitor IBMX and so it appears that the initial action of insulin is a stimulation of cyclic AMP phosphodiesterase activity which lowers the tissue concentration of cyclic AMP and so counters the actions of hormones that act by raising the tissue concentration of cyclic AMP. This model for the mode of action of insulin is supported by the finding that insulin also interferes with the glycogenolytic actions of adrenaline, a second hormone which acts by raising tissue cyclic AMP concentrations.
Gen Comp Endocrinol 1986 Jan
PMID:Glucagon and insulin regulate in vitro hepatic glycogenolysis in the axolotl Ambystoma mexicanum via changes in tissue cyclic AMP concentration. 241 34

The effects of human chorionic gonadotropin (HCG), forskolin, cyclic nucleotides, the phosphodiesterase inhibitors IBMX and theophylline, cyanoketone, and cycloheximide on the production of estradiol-17 beta by isolated ovarian follicles of vitellogenic goldfish (Carassius auratus) were examined using 18-hr incubations. HCG and all test agents which are known to increase intracellular concentrations of cAMP significantly stimulated the production of estradiol-17 beta. However, dibutyryl cGMP was unable to stimulate estradiol-17 beta production at any concentration used (1-10 mM). Cyanoketone at a concentration of 1 micrograms/ml completely blocked forskolin-induced estradiol-17 beta production. Even in the presence of cyanoketone, however, forskolin stimulated conversion of exogenous testosterone to estradiol-17 beta in a dose-dependent manner, suggesting the involvement of an adenylate-cyclase system in the induction of aromatase activation by vitellogenic follicles of goldfish. Cycloheximide also completely abolished HCG-induced estradiol-17 beta production when this inhibitor was added within the first 1 hr after the addition of HCG. These results provide evidence that the stimulation of estradiol-17 beta by goldfish vitellogenic follicles in response to HCG is dependent upon the synthesis of new protein.
Gen Comp Endocrinol 1986 Jul
PMID:The in vitro effects of cyclic nucleotides, cyanoketone, and cycloheximide on the production of estradiol-17 beta by vitellogenic ovarian follicles of goldfish (Carassius auratus). 242 92

Conflicting reports have appeared regarding the role of cAMP in regulating resorption of the tadpole tail during anuran metamorphosis. That cyclic nucleotide has been suggested as a mediator of the effects of both the thyroid hormones and prolactin. We tested the effects of cAMP and its derivatives dibutyryl-cAMP and 8-bromo-cAMP on explants of tail fin from tadpoles of Rana catesbeiana maintained in tissue culture. Unmodified cAMP (0.1, 2 mM) did not influence resorption. Dibutyryl-cAMP (0.1, 1 mM) and 8-bromo-cAMP (1 mM) inhibited resorption of explants induced by thyroxine (T4). The phosphodiesterase inhibitor isobutylmethylxanthine similarly inhibited regression of explants cultured with T4. None of these agents affected the increase in specific activity of hexosaminidase brought about by T4. Although the effects of cAMP in antagonizing tail resorption were similar to those of prolactin, we found no direct effect of prolactin on levels of cAMP in cultured tail fin. Thus, the effects of prolactin appear not to be mediated by increased levels of cAMP. We conclude, however, that the elevation of cellular levels of cAMP does inhibit the resorptive action of T4.
Gen Comp Endocrinol 1986 Oct
PMID:Investigations on the role of cAMP in regulating resorption of the tail fin from tadpoles of Rana catesbeiana. 243 9

The specific inhibitor of cAMP phosphodiesterase theophylline has been shown to evoke in L929 cells 2.3-fold induction of 2-5A-synthetase activity and 3.5-fold superinduction of the same enzyme activity while acting in combination with actinomycin D. It has been shown also that temporal coincidence of 2-5A-synthetase induction with the active period of interferon production resulted in 8-16 times decrease in the level of interferon production. The result was supported by the experiments of superinduced cells (containing the high stable level of 2-5A-synthetase) fusion with monolayer of poly(I).poly(C)-induced L929 cells (taken at the start of interferon production). In this case the production of interferon was dramatically decreased in comparison with the control. Possible role of 2-5A-synthetase in regulation of interferon production is discussed.
Mol Gen Mikrobiol Virusol 1988 Feb
PMID:[Effect of modulation of the production of interferon by L-929 cells treated with theophylline]. 245 96

The effects of bovine parathyroid hormone (bPTH1-84) on the stimulation of intracellular cyclic-AMP [cAMP] were investigated in an in vitro preparation of Necturus maculosus antral mucosa. When the antrum was exposed to 1, 5, 10, or 100 nM bPTH1-84, there was an approximately 2-fold nonlinear increase in tissue [cAMP] over basal values. The pretreatment of the antral mucosa with 1 mM isobutylmethylxanthine (IBMX, a phosphodiesterase inhibitor) increased with detectability of mucosal [cAMP]. The addition of 1, 5, 10, or 100 nM bPTH1-84 to tissues pretreated with IBMX resulted in an approximately 3.5-fold linear increase in mucosal [cAMP] over basal values. The time course of the generation of mucosal cAMP to 10 nM bPTH1-84 resulted in a small but significant transient increase at 2.5 min after the addition of bPTH1-84 but no change in the medium [cAMP]. In tissues pretreated with 1 mM IBMX the response to 10 nM bPTH1-84 was a large biphasic increase of [cAMP] at 2.5 min that progressively declined to near basal values by 15 min. There was also a significant sustained increase in the [cAMP] in the bathing medium at 2.5 min of tissues pretreated with IBMX followed by 10 nM bPTH1-84. These results suggest the presence of an adenylate cyclase that can be activated by a mammalian bPTH1-84 in elevating intracellular cAMP levels in the N. maculosus antral mucosa.
Gen Comp Endocrinol 1989 Aug
PMID:Effects of parathyroid hormone on cyclic-AMP concentrations of in vitro Necturus maculosus gastric antrum. 247 16

The Ca2+ dependence of the kinetics and light sensitivity of light-activated phosphodiesterase was studied with a pH assay in toad and bovine rod disk membranes (RDM), and in a reconstituted system containing GTP-binding protein, phosphodiesterase and rhodopsin kinase. Three statistics, peak hydrolytic velocity, turnoff time, and time to peak velocity, were measured. ATP decreased phosphodiesterase light sensitivity nearly 10-fold and accelerated the dim-flash kinetics of cGMP hydrolysis when compared to those with GTP alone. CA2+ reversed all of the effects of ATP, Ca2+ increased peak velocity, turnoff time, and time to peak velocity, to the values obtained with GTP alone. The Ca2+ dependence of peak velocity and turnoff time can be characterized as hyperbolic saturation functions with a K0.5 for Ca2+ of 1.0-1.5 mM in toad RDM. In bovine RDM the Ca2+ dependence of peak velocity and turnoff time has a K0.5 of 0.1 mM Ca2+. The Ca2+ dependence in the reconstituted system is similar to that in bovine RDM for peak velocity (K0.5 = 0.1 mM Ca2+) but differs for turnoff time (K0.5 = 2.5 mM Ca2+). We tested the hypothesis that a soluble modulator, normally required to confer submicromolar Ca2+ sensitivity, was too dilute in our assay by comparing data obtained at one RDM concentration with those obtained at 10-fold higher RDM, and therefore a constituent protein, concentration. We observe no difference and present a formal analysis of these data that excludes the hypothesis that the soluble modulator binds its target protein with Kd less than 5 microM. The lack of submicromolar Ca2+ dependence of any of the steps in the cGMP cascade that underlie cGMP phosphodiesterase activation and inactivation in vitro argues against Ca2+ regulation of these steps having a significant role in the light adaptation of the intact rod.
J Gen Physiol 1989 Jun
PMID:Calcium dependence of the activation and inactivation kinetics of the light-activated phosphodiesterase of retinal rods. 254 75


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