scholarly journals Cholera Toxin B Subunit Activates Arachidonic Acid Metabolism

1999 ◽  
Vol 67 (2) ◽  
pp. 794-799 ◽  
Author(s):  
Johnny W. Peterson ◽  
Richard A. Finkelstein ◽  
Juan Cantu ◽  
Deborah L. Gessell ◽  
Ashok K. Chopra
Keyword(s):  
Arachidonic Acid ◽  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Prostaglandin E ◽  
Activation Process ◽  
Transferase Activity ◽  
Cholera Toxin B Subunit ◽  
Lymphoma Cells ◽  
Adp Ribosylation ◽  
Stimulation Of

ABSTRACT Cholera toxin (CT) increases intestinal secretion of water and electrolytes and modulates the mucosal immune response by stimulating cellular synthesis of arachidonic acid (AA) metabolites (e.g., prostaglandin E2), as well as the intracellular second messenger cyclic AMP (cAMP). While much is known about the mechanism of CT stimulation of adenylate cyclase, the toxin’s activation of phospholipase A2, which results in increased hydrolysis of AA from membrane phospholipids, is not well understood. To determine whether CT activation of AA metabolism requires CT’s known enzymatic activity (i.e., ADP-ribosylation of GSα), we used native CT and a mutant CT protein (CT-2*) lacking ADP-ribose transferase activity in combination with S49 wild-type (WT) and S49 cyc− murine Theta (Th)1.2-positive lymphoma cells deficient in GSα. The experimental results showed that native CT stimulated the release of [3H[AA from S49 cyc− cells at a level similar to that for S49 WT cells, indicating that GSα is not essential for this process. Further, levels of cAMP in the CT-treated cyc− cells remained the same as those in the untreated control cells. The ADP-ribosyltransferase-deficient CT-2* protein, which was incapable of increasing synthesis of cAMP, displayed about the same capacity as CT to evoke the release of [3H]AA metabolites from both S49 WT and cyc− cells. We concluded that stimulation of arachidonate metabolism in S49 murine lymphoma cells by native CT does not require enzymatically functional CT, capable of catalyzing the ADP-ribosylation reaction. These results demonstrated for the first time that stimulation of adenylate cyclase by CT and stimulation of AA metabolism by CT are not necessarily coregulated. In addition, the B subunits purified from native CT and CT-2* both simulated the release of [3H]AA from S49 cyc− cells and murine monocyte/macrophage cells (RAW 264.7), suggesting a receptor-mediated cell activation process of potential importance in enhancing immune responses to vaccine components.

scholarly journals Requirement for guanosine triphosphate for cholera-toxin-catalysed incorporation of adenosine diphosphate ribose into rat liver plasma membranes and for activation of adenylate cyclase

1980 ◽  
Vol 186 (3) ◽  
pp. 749-754 ◽  
Author(s):  
C A Doberska ◽  
A J S MacPherson ◽  
B R Martin
Keyword(s):  
Plasma Membrane ◽  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Adenosine Diphosphate ◽  
Activation Process ◽  
Liver Plasma Membrane ◽  
Adp Ribosylation ◽  
A Subunit

1. Cholera toxin was shown to require the presence of GTP to activate rat liver plasma-membrane adenylate cyclase. ATP did not affect the activation process. 2. Cholera toxin catalysed the incorporation of 32P from NAD labelled in the alpha-phosphate group of the ADP moiety into a rat liver plasma-membrane protein with a subunit mol.wt. of 42 500. This is taken to demonstrate ADP-ribosylation. The ADP-ribosylation of this protein also required GTP and was unaffected by ATP. 3. Nicotinamide inhibited both the activation of adenylate cyclase by cholera toxin and the ADP-ribosylation of the protein of 42 500 subunit mol wt. Neither the activation nor the ADP-ribosylation could be reversed by treatment with nicotinamide in the presence of cholera toxin.

scholarly journals Requirements for cholera toxin-dependent ADP-ribosylation of the purified regulatory component of adenylate cyclase.

1982 ◽  
Vol 257 (1) ◽  
pp. 20-23 ◽  
Author(s):  
L.S. Schleifer ◽  
R.A. Kahn ◽  
E. Hanski ◽  
J.K. Northup ◽  
P.C. Sternweis ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Adp Ribosylation

scholarly journals Adrenaline Stimulation of Phospholipid Metabolism in Adipocyte Ghosts

1987 ◽  
Vol 40 (4) ◽  
pp. 405
Author(s):  
David Mann ◽  
Audrey M Bersten
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Linoleic Acid ◽  
Adenylate Cyclase ◽  
Phospholipid Metabolism ◽  
Dependent Manner ◽  
Long Chain Fatty Acids ◽  
Membrane Phospholipids ◽  
Dose Dependent ◽  
Stimulation Of

The incorporation of long-chain fatty acids into phospholipids has been detected in adipocyte ghosts that were incubated with [1_14 C] stearic, [1_14 C] linoleic or [l_14C] arachidonic acid. Adrenaline and adenosine activated this incorporation within 15 s of exposure of the ghosts to the hormones and the response was dose dependent. Maximum incorporation of labelled linoleic acid occurred at 10-5 M adrenaline and 10-7 M adenosine. The a-agonist phenylephrine and the ~-agonist isoproterenol were also shown to stimulate the incorporation of fatty acid in a dose dependent manner. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were each labelled preferentially with linoleic or arachidonic acid. p-Bromophenacylbromide, quinacrine and centrophenoxine inhibited the adrenaline-stimulated incorporation of fatty acids into ghost membrane phospholipids, and p-bromophenacylbromide also reduced the activation of adenylate cyclase by adrenaline. NaF, an activator of adenylate cyclase, like adrenaline, stimulated the incorporation of linoleic acid into ghost membrane phospholipids.

Effects of temperature on ADP-ribosylation factor stimulation of cholera toxin activity

Biochemistry ◽  
1993 ◽  
Vol 32 (2) ◽  
pp. 561-566 ◽  
Author(s):  
Toshihiko Murayama ◽  
Su Chen Tsai ◽  
Ronald Adamik ◽  
Joel Moss ◽  
Martha Vaughan
Keyword(s):  
Cholera Toxin ◽  
Adp Ribosylation ◽  
Effects Of Temperature ◽  
Adp Ribosylation Factor ◽  
Stimulation Of

Distinct cellular localization of mRNAs for three subtypes of prostaglandin E receptor in kidney

1994 ◽  
Vol 266 (5) ◽  
pp. F823-F828 ◽  
Author(s):  
Y. Sugimoto ◽  
T. Namba ◽  
R. Shigemoto ◽  
M. Negishi ◽  
A. Ichikawa ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Cellular Localization ◽  
Mouse Kidney ◽  
Prostaglandin E ◽  
Outer Medulla ◽  
Multiple Functions ◽  
Collecting Ducts ◽  
Distal Tubules ◽  
Stimulation Of

Distribution of the mRNAs for three subtypes of prostaglandin E (PGE) receptors in the mouse kidney was investigated by in situ hybridization. The mRNA for EP1 subtype, which is coupled to Ca2+ mobilization, was specifically localized to the collecting ducts from the cortex to the papilla. The mRNA for EP2 subtype, which is linked to stimulation of adenylate cyclase, was localized to the glomeruli. The mRNA for EP3 subtype, which is coupled to inhibition of adenylate cyclase, was located densely in the tubules in the outer medulla and in the distal tubules in the cortex. These results exhibit distinct cellular localization of three subtypes of PGE receptor in the kidney and suggest that PGE2 exerts multiple functions via these subtypes expressed in different segments of the nephron.

scholarly journals The cross-regulation of Gi-protein by cholera toxin involves a phosphorylation by protein kinase A

1995 ◽  
Vol 306 (3) ◽  
pp. 765-769 ◽  
Author(s):  
R Levistre ◽  
M Berguerand ◽  
G Bereziat ◽  
J Masliah
Keyword(s):  
Arachidonic Acid ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Cholera Toxin ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Adp Ribosylation ◽  
Gi Proteins ◽  
Kinase A

Pretreatment of alveolar macrophages with cholera toxin inhibits the release of arachidonic acid induced by the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine. The results presented here show that cholera toxin might exert its inhibitory effect through the phosphorylation of Gi alpha by protein kinase A (PKA). (1) Gi-proteins from cells pretreated with cholera toxin showed parallel increases in their sensitivity to ADP-ribosylation by toxins in vitro and in Gi alpha phosphorylation. By contrast, the Gi alpha concentration was unchanged. (2) Cholera toxin pretreatment also decreased the functional activity of Gi, as assessed by the inhibition (80%) of agonist-induced binding of guanosine-5′-[gamma-thio]triphosphate (GTP[gamma S]). (3) These effects of cholera toxin were blocked by a specific PKA inhibitor, N-(2-[methyl-amino]ethyl)-3-isoquinolinesulphonamide dihydrochloride (H8) and mimicked by a cyclic AMP (cAMP) analogue and a phosphatase inhibitor. (4) Gi alpha was also phosphorylated in vitro by the catalytic subunit of PKA. In contrast with other cell systems, the stimulation of protein kinase C seems to have no effect on the sensitivity of Gi to ADP-ribosylation or on its phosphorylation. Therefore, the phosphorylation of Gi-proteins by PKA seems to be the actual target of the negative control of arachidonic acid release via the cAMP-mediated pathway.

scholarly journals Loss of prostaglandin E2 release from immortalized urothelial cells obtained from interstitial cystitis patient bladders

2008 ◽  
Vol 294 (5) ◽  
pp. F1129-F1135 ◽  
Author(s):  
Prerna Rastogi ◽  
Alice Rickard ◽  
Nikolay Dorokhov ◽  
David J. Klumpp ◽  
Jane McHowat
Keyword(s):  
Arachidonic Acid ◽  
Interstitial Cystitis ◽  
Prostaglandin E ◽  
Arachidonic Acid Release ◽  
Urothelial Cells ◽  
Cell Numbers ◽  
Interstitial Cystitis Patient ◽  
Acid Release ◽  
Increased Susceptibility ◽  
Stimulation Of

Interstitial cystitis (IC) is associated with increased activated mast cell numbers in the bladder and impairment of the barrier function of the urothelium. We stimulated immortalized urothelial cells derived from the inflamed region of IC bladders (SR22A or SM28 abn) or from healthy bladders (PD07i or PD08i) with tryptase and measured phospholipase A2 (PLA2) activity and the resultant release of arachidonic acid and prostaglandin E2 (PGE2). Tryptase stimulation of either PD07i or SR22A resulted in similar increases in PLA2 activity and arachidonic acid release. However, tryptase stimulation of SR22A and SM28 abn did not result in a significant increase in PGE2 release compared with the increase in PGE2 release from tryptase-stimulated PD07i and PD08i cells. Expression of mRNA for cyclooxygenase-2 and PGE synthase was lower and mRNA for 15-hydroxyprostaglandin dehydrogenase was higher in SR22A compared with PD07i, suggesting that both decreased synthesis and increased metabolism are responsible for the lack of a PGE2 response in tryptase-stimulated SR22A cells. Since PGE2 is a cytoprotective eicosanoid, the failure to produce this metabolite in cells isolated from the IC bladder may represent an increased susceptibility to damage by proinfammatory stimuli.

Cholera-toxin-dependent ADP-ribosylation of the adenylate cyclase regulatory protein in turkey erythrocyte membranes

1981 ◽  
Vol 209 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Robert W. Downs ◽  
Sharon A. Reen ◽  
Michael A. Levine ◽  
Gerald D. Aurbach ◽  
Allen M. Spiegel
Keyword(s):  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Regulatory Protein ◽  
Erythrocyte Membranes ◽  
Adp Ribosylation
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