scholarly journals Adenylate cyclase, cyclic AMP and extracellular-signal-regulated kinase-2 in airway smooth muscle: modulation by protein kinase C and growth serum

1995 ◽  
Vol 306 (3) ◽  
pp. 723-726 ◽  
Author(s):  
N Moughal ◽  
P A Stevens ◽  
D Kong ◽  
S Pyne ◽  
N J Pyne
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Airway Smooth Muscle ◽  
Phospholipase D ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Extracellular Signal

Bradykinin and phorbol 12-myristate 13-acetate stimulate adenylate cyclase activity in serum-depleted cultured airway smooth muscle via a protein kinase C (PKC)-dependent pathway. The probable target is the type II adenylate cyclase, which can integrate coincident signals from both PKC and Gs. Therefore, activation of Gs (by cholera-toxin pre-treatment) amplified the bradykinin-stimulated cyclic AMP signal and concurrently attenuated the partial activation of extracellular-signal-regulated kinase-2 (ERK-2) by bradykinin. We have previously demonstrated that, in order to induce full activation of ERK-2 with bradykinin, it is necessary to obliterate PKC-stimulated cyclic AMP formation. We concluded that the cyclic AMP signal limits the magnitude of ERK-2 activation [Pyne, Moughal, Stevens, Tolan and Pyne (1994) Biochem. J. 304, 611-616]. The present study indicates that the bradykinin-stimulated ERK-2 pathway is entirely cyclic AMP-sensitive, and suggests that coincident signal detection by adenylate cyclase may be an important physiological route for the modulation of early mitogenic signalling. Furthermore, the direct inhibition of adenylate cyclase activity enables bradykinin to induce DNA synthesis, indicating that the PKC-dependent activation of adenylate cyclase limits entry of cells into the cell cycle. These studies suggest that the mitogenicity of an agonist may be governed, in part, by its ability to stimulate an inhibitory cyclic AMP signal pathway in the cell. The activation of adenylate cyclase by PKC appears to be downstream of phospholipase D. However, in cells that were maintained in growth serum (i.e. were not growth-arrested), bradykinin was unable to elicit a PKC-stimulated cyclic AMP response. The lesion in the signal-response coupling was not at the level of either the receptor or phospholipase D, which remain functionally operative and suggests modification occurs at either PKC or adenylate cyclase itself. These studies are discussed with respect to the cell signal regulation of mitogenesis in airway smooth muscle.

scholarly journals Protein kinase C-dependent cyclic AMP formation in airway smooth muscle: the role of type II adenylate cyclase and the blockade of extracellular-signal-regulated kinase-2 (ERK-2) activation

1994 ◽  
Vol 304 (2) ◽  
pp. 611-616 ◽  
Author(s):  
N J Pyne ◽  
N Moughal ◽  
P A Stevens ◽  
D Tolan ◽  
S Pyne
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Airway Smooth Muscle ◽  
Type Ii ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Extracellular Signal

Bradykinin activates adenylate cyclase via a pathway that involves the ‘up-stream’ regulation of phospholipase D (PLD)-catalysed hydrolysis of phosphatidylcholine and activation of protein kinase C (PKC) in airway smooth muscle [Stevens, Pyne, Grady and Pyne (1994) Biochem. J. 297, 233-239]. Coincident signal (Gs alpha and PKC) amplification of the cyclic AMP response can be completely attenuated either by diverting PLD-derived phosphatidate or by inhibiting PKC. In this regard, the coincident signal detector type II adenylate cyclase is expressed as a 110/112 kDa polypeptide in these cells. PKC alpha is not involved in the activation of adenylate cyclase, since a B2-receptor antagonist (NPC567, 10 microM) blocked its bradykinin-stimulated translocation to the membrane and was without effect against both bradykinin-stimulated PLD activity and cyclic AMP formation. Cyclic AMP formation can also be activated by platelet-derived growth factor (PDGF), via a PKC-dependent pathway, although the magnitude of the response is less than that elicited by bradykinin. Nevertheless, these results indicate that multiple receptor types employ PKC to initiate cyclic AMP signals. PDGF (10 ng/ml) elicited the marked sustained activation of extracellular-signal-regulated kinase-2 (ERK-2), whereas bradykinin (1 microM) provoked only modest transient activation of ERK-2. Deoxyadenosine (0.1 mM), a P-site inhibitor of adenylate cyclase, blocked bradykinin-stimulated cyclic AMP formation and converted the activation of ERK-2 into a sustained response. Thus the PKC-stimulated cyclic AMP response can limit the activation of ERK-2 in response to bradykinin. These studies indicate that the integration of distinct signal pathways by adenylate cyclase can determine the kinetics of ERK activation, an enzyme that appears to be important for mitogenic progression.

scholarly journals The differential regulation of cyclic AMP by sphingomyelin-derived lipids and the modulation of sphingolipid-stimulated extracellular signal regulated kinase-2 in airway smooth muscle

1996 ◽  
Vol 315 (3) ◽  
pp. 917-923 ◽  
Author(s):  
Susan PYNE ◽  
Nigel J. PYNE
Keyword(s):  
Smooth Muscle ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Dna Synthesis ◽  
Airway Smooth Muscle ◽  
Short Chain ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Sphingosine Phosphate ◽  
Dependent Mechanism

We report that sphingosine and short-chain ceramides activate adenylate cyclase and stimulate intracellular cyclic AMP formation in airway-smooth-muscle (ASM) cells. In each case, there is a conditional requirement for GTP-Gsα. Sphingosine utilizes a protein kinase C-dependent pathway to elicit activation of adenylate cyclase, whereas for short-chain ceramides the mechanism remains unidentified. In contrast, sphingosine phosphate inhibits Gs-stimulated cyclic AMP formation via a Gi-dependent mechanism. Therefore, the potential interconversion of sphingosine and sphingosine phosphate is a switch that can elicit reciprocal changes in cyclic AMP levels. This may have a significant impact upon the regulation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal specific kinase (JNK) by sphingolipids and may help to explain how growth factors that utilize these second messengers evoke pleiotropic responses such as proliferation and cell survival. In this context, short-chain ceramides are poor stimulators of ERKs in ASM cells, and sphingosine is inactive, whereas both sphingolipids are powerful activators of the JNK module. Activated JNK catalyses N-terminal phosphorylation of c-Jun, a kinase cascade that programmes growth arrest. Therefore, in blocking ceramide-stimulated ERK-2 activity, cyclic AMP may allow the ceramide-dependent activation of JNK to programme cells to opt out of the cell cycle. In contrast, sphingosine phosphate activates ERK-2, potentiates growth-factor-stimulated DNA synthesis and fails to activate JNK, indicating that its sequential formation from ceramide and sphingosine may commit cells to DNA synthesis. ERK-2 can be activated by both cyclic AMP-sensitive c-Raf-1 kinase-dependent and cyclic AMP-insensitive c-Raf-1 kinase-independent pathways in ASM cells. In this context, sphingosine phosphate activates ERK-2 exclusively via c-Raf-1 kinase. Sphingosine phosphate-stimulated ERK-2 activity is also abolished by pertussis toxin, indicating that c-Raf-1 kinase is activated via a Gi-dependent mechanism.

scholarly journals Glucose Activates Protein Kinase C-ζ/λ through Proline-rich Tyrosine Kinase-2, Extracellular Signal-regulated Kinase, and Phospholipase D

2001 ◽  
Vol 276 (38) ◽  
pp. 35537-35545 ◽  
Author(s):  
Gautam Bandyopadhyay ◽  
Mini P. Sajan ◽  
Yoshinori Kanoh ◽  
Mary L. Standaert ◽  
Michael J. Quon ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Phospholipase D ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Tyrosine Kinase 2 ◽  
Extracellular Signal
Sign in / Sign up

Export Citation Format

Share Document