scholarly journals Increase in Endogenous and Exogenous Cyclic AMP Levels Inhibits Sclerotial Development in Sclerotinia sclerotiorum

1998 ◽  
Vol 64 (7) ◽  
pp. 2539-2544 ◽  
Author(s):  
Jeffrey A. Rollins ◽  
Martin B. Dickman
Keyword(s):  
Cyclic Amp ◽  
Sclerotinia Sclerotiorum ◽  
Growth And Development ◽  
Mycelial Growth ◽  
Dependent Manner ◽  
Wild Type ◽  
Concentration Dependent Manner ◽  
Sclerotial Development ◽  
Camp Levels ◽  
Methyl Xanthine

ABSTRACT Growth and development of a wild-type Sclerotinia sclerotiorum isolate were examined in the presence of various pharmacological compounds to investigate signal transduction pathways that influence the development of sclerotia. Compounds known to increase endogenous cyclic AMP (cAMP) levels in other organisms by inhibiting phosphodiesterase activity (caffeine and 3-isobutyl-1-methyl xanthine) or by activating adenylate cyclase (NaF) reduced or eliminated sclerotial development in S. sclerotiorum. Growth in the presence of 5 mM caffeine correlated with increased levels of endogenous cAMP in mycelia. In addition, incorporation of cAMP into the growth medium decreased or eliminated the production of sclerotia in a concentration-dependent manner and increased the accumulation of oxalic acid. Inhibition of sclerotial development was cAMP specific, as exogenous cyclic GMP, AMP, and ATP did not influence sclerotial development. Transfer of developing cultures to cAMP-containing medium at successive time points demonstrated that cAMP inhibits development prior to or during sclerotial initiation. Together, these results indicate that cAMP plays a role in the early transition between mycelial growth and sclerotial development.

scholarly journals A GENETICALLY DISTINCT FORM OF CYCLIC AMP PHOSPHODIESTERASE ASSOCIATED WITH CHROMOMERE 3D4 IN DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 91 (3) ◽  
pp. 521-535
Author(s):  
John A Kiger ◽  
Eric Golanty
Keyword(s):  
Drosophila Melanogaster ◽  
Cyclic Amp ◽  
Structural Gene ◽  
Regulatory Gene ◽  
Heat Stability ◽  
Normal Female ◽  
Dependent Manner ◽  
Cyclic Amp Phosphodiesterase ◽  
Heat Stable ◽  
Camp Levels

ABSTRACT Two cyclic AMP phosphodiesterase enzymes (E.C.3.1.4.17) are present in homogenates of adult Drosophila melanogaster. The two enzymes differ from one another in heat stability, affinity for Mg++, Ca++ activation and molecular weight. They do not differ markedly in their affinities for cyclic AMP, and both exhibit anomalous Michaelis-Menten kinetics. The more heatlabile enzyme is controlled in a dosage-dependent manner by chromomere 3D4 of the X chromosome and is absent in flies that are deficient for chromomere 3D4. Chromomere 3D4 is also necessary for the maintenance of normal cAMP levels, for male fertility, and for normal female fertility and oogenesis. The structural gene(s) for the more heat-stable enzyme is located outside of chromomeres 3C12-3D4. Whether 3D4 contains a structural gene, or a regulatory gene necessary for the presence of the labile enzyme, remains to be determined.

scholarly journals Brassinolide Enhances the Level of Brassinosteroids, Protein, Pigments, and Monosaccharides in Wolffia arrhiza Treated with Brassinazole

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1311
Author(s):  
Magdalena Chmur ◽  
Andrzej Bajguz
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Plant Growth And Development ◽  
Concentration Dependent Manner ◽  
Spectrophotometric Methods ◽  
Synthetic Inhibitor ◽  
Wolffia Arrhiza ◽  
First Time

Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz.

scholarly journals Bicarbonate Evokes Reciprocal Changes in Intracellular Cyclic di-GMP and Cyclic AMP Levels in Pseudomonas aeruginosa

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 519
Author(s):  
Kasidid Ruksakiet ◽  
Balázs Stercz ◽  
Gergő Tóth ◽  
Pongsiri Jaikumpun ◽  
Ilona Gróf ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cyclic Amp ◽  
Biofilm Formation ◽  
Second Messengers ◽  
Brain Heart Infusion ◽  
Ambient Air ◽  
Dependent Manner ◽  
Environmental Signals ◽  
Common Causes ◽  
Camp Levels

The formation of Pseudomonas aeruginosa biofilms in cystic fibrosis (CF) is one of the most common causes of morbidity and mortality in CF patients. Cyclic di-GMP and cyclic AMP are second messengers regulating the bacterial lifestyle transition in response to environmental signals. We aimed to investigate the effects of extracellular pH and bicarbonate on intracellular c-di-GMP and cAMP levels, and on biofilm formation. P. aeruginosa was inoculated in a brain–heart infusion medium supplemented with 25 and 50 mM NaCl in ambient air (pH adjusted to 7.4 and 7.7 respectively), or with 25 and 50 mM NaHCO3 in 5% CO2 (pH 7.4 and 7.7). After 16 h incubation, c-di-GMP and cAMP were extracted and their concentrations determined. Biofilm formation was investigated using an xCelligence real-time cell analyzer and by crystal violet assay. Our results show that HCO3− exposure decreased c-di-GMP and increased cAMP levels in a dose-dependent manner. Biofilm formation was also reduced after 48 h exposure to HCO3−. The reciprocal changes in second messenger concentrations were not influenced by changes in medium pH or osmolality. These findings indicate that HCO3− per se modulates the levels of c-di-GMP and cAMP, thereby inhibiting biofilm formation and promoting the planktonic lifestyle of the bacteria.

scholarly journals Global Expression Profiling and Physiological Characterization of Corynebacterium glutamicum Grown in the Presence of l-Valine

2003 ◽  
Vol 69 (5) ◽  
pp. 2521-2532 ◽  
Author(s):  
C. Lange ◽  
D. Rittmann ◽  
V. F. Wendisch ◽  
M. Bott ◽  
H. Sahm
Keyword(s):  
Corynebacterium Glutamicum ◽  
Expression Profiling ◽  
Large Subunit ◽  
Mrna Level ◽  
Acetohydroxyacid Synthase ◽  
Limiting Factor ◽  
Unexpected Result ◽  
Dependent Manner ◽  
Wild Type ◽  
Concentration Dependent Manner

ABSTRACT Addition of l-valine (50 to 200 mM) to glucose minimal medium had no effect on the growth of wild-type Corynebacterium glutamicum ATCC 13032 but inhibited the growth of the derived valine production strain VAL1 [13032 ΔilvA ΔpanBC(pJC1ilvBNCD)] in a concentration-dependent manner. In order to explore this strain-specific valine effect, genomewide expression profiling was performed using DNA microarrays, which showed that valine caused an increased ilvBN mRNA level in VAL1 but not in the wild type. This unexpected result was confirmed by an increased cellular level of the ilvB protein product, i.e., the large subunit of acetohydroxyacid synthase (AHAS), and by an increased AHAS activity of valine-treated VAL1 cells. The conclusion that valine caused the limitation of another branched-chain amino acid was confirmed by showing that high concentrations of l-isoleucine could relieve the valine effect on VAL1 whereas l-leucine had the same effect as valine. The valine-caused isoleucine limitation was supported by the finding that the inhibitory valine effect was linked to the ilvA deletion that results in isoleucine auxotrophy. Taken together, these results implied that the valine effect is caused by competition for uptake of isoleucine by the carrier BrnQ, which transports all branched-chained amino acids. Indeed, valine inhibition could also be relieved by supplementing VAL1 with the dipeptide isoleucyl-isoleucine, which is taken up by a dipeptide transport system rather than by BrnQ. Interestingly, addition of external valine stimulated valine production by VAL1. This effect is most probably due to a reduced carbon usage for biomass production and to the increased expression of ilvBN, indicating that AHAS activity may still be a limiting factor for valine production in the VAL1 strain.

scholarly journals The Control of Platelet Function by Cyclic amp and Thromboxane Synthesis

1977 ◽  
Author(s):  
N.U. Bang ◽  
M.G.J. Boxer ◽  
R.O. Heidenreich ◽  
P.P.K. Ho ◽  
M.J. Schmidt
Keyword(s):  
Arachidonic Acid ◽  
Cyclic Amp ◽  
Platelet Function ◽  
Complete Inhibition ◽  
Cyclooxygenase Inhibitors ◽  
Cyclooxygenase Inhibition ◽  
Camp Levels ◽  
Methyl Xanthine

Platelet (P) levels of cyclic AMP (cAMP) and thromboxane (TX) synthesis have been identified as major regulators of P aggregation and release. We have utilized as probes drugs which either decrease TX synthesis by cyclooxygenase inhibition (aspirin and indomethacin) or which increase P cAMP (adenosine; PGE1; theophylline; isobutyl methyl xanthine; and SH-869, a dipyridamole analog) to evaluate relative contributions of cAMP and TX and their possible interreactions in mediating P function. Cyclooxygenase inhibitors at concentrations 8-16 fold lower than those inhibiting P aggregation and release caused almost complete inhibition of TXB2 synthesis from exogenous 14C-arachidonic acid (aa) and malonyldialdehyde (MDA) production in P stimulated by thrombin (T) or N-ethylmaleimide (NEM). Drugs elevating P cAMP at concentrations equal to or greater than those causing complete inhibition of P aggregation and release did not inhibit TXB2 synthesis from exogenous 14C-aa, nor did they inhibit MDA production in P stimulated by NEM or by concentrations of T sufficient to produce maximal TX synthesis.However, these drugs variably inhibited MDA production when P were stimulated at lower T concentrations causing only minor TX synthesis.Thus, elevated P cAMP did not inhibit TX synthesis from aa but appeared to weakly inhibit aa phospholipase. We conclude that TX synthesis cannot be the sole, final mediator of P aggregation and release but that these events result from as yet unidentified mechanisms modulated largely independently by TX synthesis and intra-P cAMP levels.

Inhibitory action of somatostatin-14 on hormone-stimulated cyclic adenosine monophosphate induction in porcine granulosa and luteal cells

1992 ◽  
Vol 134 (2) ◽  
pp. 297-306 ◽  
Author(s):  
K. Rajkumar ◽  
D. E. Kerr ◽  
R. N. Kirkwood ◽  
B. Laarveld
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Luteal Cells ◽  
Camp Generation ◽  
Camp Induction ◽  
Camp Levels ◽  
Somatostatin 14

ABSTRACT Somatostatin-14 (SRIF-14) inhibited, in a concentration-dependent manner, LH- and forskolin-stimulated cyclic adenosine monophosphate (cAMP) induction in porcine granulosa and luteal cells. The inhibitory effect of SRIF-14 on hormone-induced cAMP generation was more potent in porcine ovarian cells than in the GH-3 pituitary cell line. The inhibitory effect of SRIF-14 was impeded by neutralizing its biological activity with specific antiserum. Preincubation of luteal and granulosa cells with phorbol 12-myristate 13-acetate (PMA) enhanced LH- and forskolin-stimulated cAMP levels. SRIF-14 failed to inhibit LH- or forskolin-stimulated cAMP levels in cells preincubated with PMA. It is concluded that SRIF-14 inhibits hormone-stimulated cAMP induction in the porcine ovary. LH-induced protein kinase C activation may be physiologically important to alleviate the inhibitory effects of SRIF-14. Journal of Endocrinology (1992) 134, 297–306

scholarly journals Factors regulating the production of prostaglandin E2 and prostacyclin (prostaglandin I2) in rat and human adipocytes

1987 ◽  
Vol 247 (2) ◽  
pp. 389-394 ◽  
Author(s):  
B Richelsen
Keyword(s):  
Angiotensin Ii ◽  
Cyclic Amp ◽  
Prostaglandin E2 ◽  
Acetylsalicylic Acid ◽  
Dependent Manner ◽  
Human Adipocytes ◽  
Prostaglandin I2 ◽  
Concentration Dependent Manner ◽  
Rat Adipocytes ◽  
Isolated Adipocytes

The regulation of PGE2 (prostaglandin E2) and PGI2 (prostaglandin I2; prostacyclin) formation was investigated in isolated adipocytes. The formation of both PGs was stimulated by various lipolytic agents such as isoproterenol, adrenaline and dibutyryl cyclic AMP. During maximal stimulation the production of PGE2 and PGI2 (measured as 6-oxo-PGF1 alpha) was 0.51 +/- 0.04 and 1.21 +/- 0.09 ng/2 h per 10(6) cells respectively. Thus PGI2 was produced in excess of PGE2 in rat adipocytes. The production of the PGs was inhibited by indomethacin and acetylsalicylic acid in a concentration-dependent manner. The half-maximal effective concentration of indomethacin was 328 +/- 38 nM and that of acetylsalicylic acid was 38.5 +/- 5.3 microM. The PGs were maximally inhibited by 70-75% after incubation for 2 h. In contrast with their effect on PG production, the two agents had a small potentiating effect on the stimulated lipolysis (P less than 0.05). The phospholipase inhibitors mepacrine and chloroquine inhibited both PG production and triacylglycerol lipolysis and were therefore unable to indicate whether the PG precursor, arachidonic acid, originates from phospholipids or triacylglycerols in adipocytes. Angiotensin II significantly (P less than 0.05) stimulated both PGE2 and PGI2 production in rat adipocytes without affecting triacylglycerol lipolysis. Finally, it was shown that PGE2 and PGI2 were also produced in human adipocytes, although in smaller quantities than in rat adipocytes. It is concluded that the production of PGs in isolated adipocytes is regulated by various hormones. Moreover, at least two separate mechanisms for PG production may exist in adipocytes: (1) a mechanism that is activated concomitantly with triacylglycerol lipolysis (and cyclic AMP) and (2) an angiotensin II-sensitive, but lipolysis (and cyclic AMP)-independent mechanism.

A nonsclerotial pathogenic mutant of Sclerotinia sclerotiorum

1989 ◽  
Vol 35 (4) ◽  
pp. 517-520 ◽  
Author(s):  
R. Vincent Miller ◽  
Eugene J. Ford ◽  
David C. Sands
Keyword(s):  
Ultraviolet Light ◽  
Plant Species ◽  
Sclerotinia Sclerotiorum ◽  
Parental Strain ◽  
Wild Type ◽  
Physiological Studies ◽  
Sclerotial Development

A nonsclerotial mutant of Sclerotinia sclerotiorum was produced by mutagenesis with 8-methoxypsoralen and ultraviolet light. The mutant, SL-1, failed to produce sclerotia on artificial media, infested grain, or on infected plants. The mutant remained pathogenic to eight plant species susceptible to the wild-type parental strain of the fungus. The mutant, SL-1, is potentially useful for physiological studies on sclerotial development and for investigation of its potential for biological weed control.Key words: Sclerotinia, mutant, sclerotialess, biocontrol, weeds.

The Relation of Blood Adenosine Triphosphate to Changes of Mood in Affective Disorders

1974 ◽  
Vol 125 (586) ◽  
pp. 268-274 ◽  
Author(s):  
Otto Hansen ◽  
Maria Dimitrakoudi
Keyword(s):  
Cyclic Amp ◽  
Adenosine Triphosphate ◽  
Whole Blood ◽  
Dependent Manner ◽  
Uridine Diphosphate ◽  
Healthy Human ◽  
Electroconvulsive Treatment ◽  
Concentration Dependent Manner ◽  
Depressive Patients

Peripheral whole blood uridine diphosphate glucose (UDPG) has been found to be significantly elevated in psychotic depression (Hansen, 1969; 1972a, b), and this was related to an equally significant lowering of whole blood adenosine triphosphate (ATP). Addition to healthy human blood of UDPG accelerated the hydrolysis of ATP in vitro (Hansen, 1972a), and UDPG concentration dependently enhanced the activity of a vegetable ATP di-phosphohydrolase (EC 3.6.1.5), which was also inhibited by adenosine 3’, 5′-cyclic monophosphate (cyclic AMP) in a concentration-dependent manner (Hansen, 1972b). Other workers have recently published a similar inhibition of a rat heart ATPase by cyclic AMP (Dietze and Hepp, 1972), and another research group have found that sodium-potassium exchange pump changes and changes in erythrocyte membrane ATPase activity correlate significantly with mood alterations in psychotic depressive patients (Dick, Dick, Le Poidevin and Naylor, 1972; Naylor, Dick, Dick, Le Poidevin and Whyte, 1973). This paper reports a study of the relationship between blood ATP levels and mood in patients suffering from manic-depressive predictable (Jenner, 1971) short term cycle psychotic states, and in depressive patients receiving electroconvulsive treatment.

Increased susceptibility to exacerbated liver injury in hypercholesterolemic ApoE-deficient mice: potential involvement of oxysterols

2009 ◽  
Vol 296 (3) ◽  
pp. G553-G562 ◽  
Author(s):  
Natàlia Ferré ◽  
Marcos Martínez-Clemente ◽  
Marta López-Parra ◽  
Ana González-Périz ◽  
Raquel Horrillo ◽  
...  
Keyword(s):  
Liver Injury ◽  
Smooth Muscle Actin ◽  
Cell Types ◽  
Dependent Manner ◽  
Wild Type ◽  
Sod Activity ◽  
Concentration Dependent Manner ◽  
Oil Red O Staining ◽  
Cytochrome P 450 ◽  
Oxidized Products

The contribution of metabolic factors to the severity of liver disease is not completely understood. In this study, apolipoprotein E-deficient (ApoE−/−) mice were evaluated to define potential effects of hypercholesterolemia on the severity of carbon tetrachloride (CCl4)-induced liver injury. Under baseline conditions, hypercholesterolemic ApoE−/− mice showed increased hepatic oxidative stress (SOD activity/4-hydroxy-2-nonenal immunostaining) and higher hepatic TGF-β1, MCP-1, and TIMP-1 expression than wild-type control mice. After CCl4 challenge, ApoE−/− mice exhibited exacerbated steatosis (Oil Red O staining), necroinflammation (hematoxylin-eosin staining), macrophage infiltration (F4/80 immunohistochemistry), and fibrosis (Sirius red staining and α-smooth muscle actin immunohistochemistry) and more severe liver injury [alanine aminotransferase (ALT) and aspartate aminotransferase] than wild-type controls. Direct correlations were identified between serum cholesterol and hepatic steatosis, fibrosis, and ALT levels. These changes did not reflect the usual progression of the disease in ApoE−/− mice, since exacerbated liver injury was not present in untreated age-paired ApoE−/− mice. Moreover, hepatic cytochrome P-450 expression was unchanged in ApoE−/− mice. To explore potential mechanisms, cell types relevant to liver pathophysiology were exposed to selected cholesterol-oxidized products. Incubation of hepatocytes with a mixture of oxysterols representative of those detected by GC-MS in livers from ApoE−/− mice resulted in a concentration-dependent increase in total lipoperoxides and SOD activity. In hepatic stellate cells, oxysterols increased IL-8 secretion through a NF-κB-independent mechanism and upregulated TIMP-1 expression. In macrophages, oxysterols increased TGF-β1 secretion and MCP-1 expression in a concentration-dependent manner. Oxysterols did not compromise cell viability. Taken together, these findings demonstrate that hypercholesterolemic mice are sensitized to liver injury and that cholesterol-derived products (i.e., oxysterols) are able to induce proinflammatory and profibrogenic mechanisms in liver cells.

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