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.

Protein kinase A activity modulates natriuretic peptide-dependent cGMP accumulation in renal cells

1997 ◽  
Vol 272 (1) ◽  
pp. C82-C89 ◽  
Author(s):  
S. Ledoux ◽  
J. C. Dussaule ◽  
C. Chatziantoniou ◽  
N. Ardaillou ◽  
S. Vandermeersch ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Cholera Toxin ◽  
Natriuretic Peptide ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Nitric Oxide Donor ◽  
Dependent Manner ◽  
Cgmp Production ◽  
Kinase A

The purpose of this work was to examine whether the level of cAMP accumulation and protein kinase A (PKA) activity influence atrial natriuretic factor (ANF)-dependent guanosine 3',5'-cyclic monophosphate (cGMP) production in two renal cell types: rabbit cortical vascular smooth muscle cells (RCSMC) and SV-40-transformed human glomerular visceral epithelial cells (HGVEC-SV1). N-[2-(p-bromocinnamylamino)ethyl]- 5-isoquinolinesulfonamide (H-89), a PKA inhibitor, decreased ANF-stimulated cGMP production in RCSMC in a time- and concentration-dependent manner. ANF-stimulated cGMP production was markedly inhibited after prolonged 9- and 18-h incubations with 25 microM H-89 (52 and 65%, respectively) but was not altered after exposure of cells to this agent for 1 h. 1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine and N-(2-[methylamino]ethyl)-5-isoquinolinesulfonamide, protein kinase inhibitors not selective for PKA, did not reproduce the effect of H-89, even at higher concentrations (50 and 100 microM). Cycloheximide (10 microM), a protein synthesis inhibitor, limited the inhibitory effect of H-89, although alone it did not modify the ANF-stimulated cGMP production. H-89 did not affect cGMP production when it was stimulated by SIN-1, a nitric oxide donor. Prolonged incubation (18 h) with 8-bromo cAMP or cholera toxin, an activator of Gs protein resulting in adenylate cyclase stimulation, enhanced ANF-dependent cGMP production by 225 and 176%, respectively. This stimulatory effect was blocked by 25 microM H-89. 125I-ANF binding to RCSMC at 4 degrees C was not affected by preincubation of the cells with H-89. There was a 44% decrease in the expression of ANF C receptors measured as the ANF-(4-23)-displaceable 125I-ANF binding at 37 degrees C, which could not, however, explain the inhibitory effect of H-89 on cGMP production. Modulation of ANF- and C-type natriuretic peptide-dependent cGMP production by H-89 and cholera toxin was also found in HGVEC-SV1 with the same characteristics as in RCSMC. Taken together, these results suggest that PKA activity controls the function of natriuretic peptide guanylate cyclase-coupled receptors in the two cell types studied. PKA-dependent inhibition of a negatively regulatory protein distinct from the receptor itself seems necessary for a full cGMP response.

A2 adenosine receptors regulate CFTR through PKA and PLA2

2002 ◽  
Vol 282 (1) ◽  
pp. L12-L25 ◽  
Author(s):  
B. R. Cobb ◽  
F. Ruiz ◽  
C. M. King ◽  
J. Fortenberry ◽  
H. Greer ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Receptor Activation ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Δf508 Cftr ◽  
Kinase A

We investigated adenosine (Ado) activation of the cystic fibrosis transmembrane conductance regulator (CFTR) in vitro and in vivo. A2B Ado receptors were identified in Calu-3, IB-3-1, COS-7, and primary human airway cells. Ado elevated cAMP in Calu-3, IB-3-1, and COS-7 cells and activated protein kinase A-dependent halide efflux in Calu-3 cells. Ado promoted arachidonic acid release from Calu-3 cells, and phospholipase A2(PLA2) inhibition blocked Ado-activated halide efflux in Calu-3 and COS-7 cells expressing CFTR. Forskolin- and β2-adrenergic receptor-stimulated efflux were not affected by the same treatment. Cytoplasmic PLA2(cPLA2) was identified in Calu-3, IB-3-1, and COS-7 cells, but cPLA2 inhibition did not affect Ado-stimulated cAMP concentrations. In cftr(+) and cftr(−/−) mice, Ado stimulated nasal Cl− secretion that was CFTR dependent and sensitive to A2 receptor and PLA2 blockade. In COS-7 cells transiently expressing ΔF508 CFTR, Ado activated halide efflux. Ado also activated G551D CFTR-dependent halide efflux when combined with arachidonic acid and phosphodiesterase inhibition. In conclusion, PLA2 and protein kinase A both contribute to A2 receptor activation of CFTR, and components of this signaling pathway can augment wild-type and mutant CFTR activity.

scholarly journals Activity, expression and function of a second Drosophila protein kinase A catalytic subunit gene.

Genetics ◽  
1995 ◽  
Vol 141 (4) ◽  
pp. 1507-1520 ◽  
Author(s):  
A Meléndez ◽  
W Li ◽  
D Kalderon
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Essential Gene ◽  
Sequence Similarity ◽  
Catalytic Subunit ◽  
Subunit Gene ◽  
Drosophila Protein ◽  
Pka Catalytic Subunit ◽  
Kinase A

Abstract The DC2 gene was isolated previously on the basis of sequence similarity to DC0, the major Drosophila protein kinase A (PKA) catalytic subunit gene. We show here that the 67-kD Drosophila DC2 protein behaves as a PKA catalytic subunit in vitro. DC2 is transcribed in mesodermal anlagen of early embryos. This expression depends on dorsal but on neither twist nor snail activity. DC2 transcriptional fusions mimic this embryonic expression and are also expressed in subsets of cells in the optic lamina, wing disc and leg discs of third instar larvae. A saturation screen of a small deficiency interval containing DC2 for recessive lethal mutations yielded no DC2 alleles. We therefore isolated new deficiencies to generate deficiency trans-heterozygotes that lacked DC2 activity. These animals were viable and fertile. The absence of DC2 did not affect the viability or phenotype of imaginal disc cells lacking DC0 activity or embryonic hatching of animals with reduced DC0 activity. Furthermore, transgenes expressing DC2 from a DC0 promoter did not efficiently rescue a variety of DC0 mutant phenotypes. These observations indicate that DC2 is not an essential gene and is unlikely to be functionally redundant with DC0, which has multiple unique functions during development.

scholarly journals Effect of Protein Kinase A Activity on the Association of ADP-ribosylation Factor 1 to Golgi Membranes

2000 ◽  
Vol 275 (25) ◽  
pp. 19050-19059 ◽  
Author(s):  
Maria Esther Martı́n ◽  
Josefina Hidalgo ◽  
Jose Luis Rosa ◽  
Pascal Crottet ◽  
Angel Velasco
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Adp Ribosylation ◽  
Golgi Membranes ◽  
Adp Ribosylation Factor ◽  
Kinase A

scholarly journals Terbutaline, forskolin and cAMP reduce secretion of aqueous humour in the isolated bovine eye

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244253
Author(s):  
Mohammad Shahidullah ◽  
William Stuart Wilson ◽  
Kazi Rafiq ◽  
Mahmudul Hasan Sikder ◽  
Jannatul Ferdous ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinase A ◽  
Aqueous Humour ◽  
Calcium Release ◽  
Drug Effects ◽  
Inhibitory Effect ◽  
Plateau Phase ◽  
Intracellular Ca ◽  
Kinase A

In order to elucidate involvement of cyclic AMP and intracellular Ca2+,[Ca2+]i, in the modulation of aqueous humour formation (AHF), we studied the effects of terbutaline, forskolin and 8-Br-cAMP in the isolated bovine eye. We also studied the interaction of cAMP on calcium signaling in cultured ciliary epithelial (CE) cells. Drug effects on AHF were measured by fluorescein dilution. Drug effects on [Ca2+]i were studied by the fura-2 fluorescence ratio technique. Terbutaline (100 nmol-100 M), forskolin (30 nM-100 M) or 8-Br-cAMP (100 nM– 10 μM), administered in the arterial perfusate produced significant reductions in AHF. The AH reducing effect of terbutaline was blocked by a selective inhibitor of protein kinase A (KT-5720). ATP (100 M) caused a rapid, transient (peak) increase in [Ca2+]i followed by a sustained plateau phase lasting more than 5 minutes. Preincubation of the cells (6 min) with terbutaline, forskolin or 8-Br-cAMP significantly reduced the peak calcium response to ATP. The sustained plateau phase of the response, on the other hand, was augmented by each of the agents. KT-5720 partially reversed the inhibitory effect of terbutaline on the peak and totally inhibited its effect on the plateau phase. These data indicate: (a) that AHF in the bovine eye can be manipulated through cyclic AMP, operating via protein kinase A, (b) that protein kinase A can affect [Ca2+]i homeostasis, (c) that calcium release from the intracellular store, not the entry, affects AHF, and (d) that interaction of [Ca2+]i with cAMP plays a role in modulating AH secretion.

scholarly journals Adenosine pretreatment attenuates angiotensin II-mediated p38 MAPK activation in a protein kinase A dependent manner

2010 ◽  
Vol 4 (5) ◽  
pp. 721-729
Author(s):  
Hamid Yaghooti ◽  
Mohsen Firoozrai ◽  
Soudabeh Fallah ◽  
Mohammad Reza Khorramizadeh
Keyword(s):  
Angiotensin Ii ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
P38 Mapk ◽  
Inflammatory Mediators ◽  
Endothelial Permeability ◽  
Renin Angiotensin System ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Kinase A

Abstract Background: Adenosine is known as a protective and anti-inflammatory nucleoside. Angiotensin II is the main hormone of the renin-angiotensin system. It is associated with endothelial permeability, recruitment, and activation of the immune cells through induction of inflammatory mediators. Matrix metalloproteinase-9 (MMP-9) plays an important role in inflammatory processes mediated by macrophages. Objectives: Investigate whether adenosine pretreatment modulates angiotensin II-induced MMP-9 expression and activation of signaling molecules. Methods: Human monocytic U-937 cells were treated with either adenosine or angiotensin II alone or angiotensin II following a pretreatment with adenosine. Supernatants were analyzed for MMP-9 activity by zymography method. MMP-9 gene expression was analyzed using real-time PCR. Activation of inflammatory mediators IκB-α, NF-κB, JNK, p38 MAPK, and STAT3 were analyzed by a multi-target ELISA kit. Association of Protein kinase A (PKA) in adenosine effects was studied by pre-incubation with H89, a selective PKA inhibitor. Results: Treatment of the cells with angiotensin II significantly increased MMP-9 production (p <0.05). Adenosine pretreatment did not attenuate this angiotensin II effect. Angiotensin II treatment induced NF-κB, JNK and p38 activation. Pretreatment with adenosine prior to angiotensin II stimulation showed a 40% inhibitory effect on p38 induction (p <0.05). This effect was reversed by PKA inhibition. Conclusion: The present data confirmed that monocytic MMP-9 was a target gene for angiotensin II. Adenosine pretreatment did not inhibit MMP-9 increase in response to angiotensin II. However, it showed a potential inhibitory effect on angiotensin II inflammatory signaling.

scholarly journals Membrane-Bound Protein Kinase A Inhibits Smooth Muscle Cell Proliferation In Vitro and In Vivo by Amplifying cAMP–Protein Kinase A Signals

2001 ◽  
Vol 88 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Ciro Indolfi ◽  
Eugenio Stabile ◽  
Carmela Coppola ◽  
Adriana Gallo ◽  
Cinzia Perrino ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Smooth Muscle Cell ◽  
Protein Kinase A ◽  
Membrane Bound ◽  
Proliferation In Vitro ◽  
Kinase A
Sign in / Sign up

Export Citation Format

Share Document