scholarly journals Extracellular ATP induces the release of calcium from intracellular stores without the activation of protein kinase C in Swiss 3T6 mouse fibroblasts.

1989 ◽  
Vol 86 (12) ◽  
pp. 4530-4534 ◽  
Author(s):  
F. A. Gonzalez ◽  
E. Rozengurt ◽  
L. A. Heppel
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Extracellular Atp ◽  
Mouse Fibroblasts ◽  
Kinase C

Ca2+ mobilization by extracellular ATP in rat cardiac myocytes: regulation by protein kinase C and A

1992 ◽  
Vol 263 (5) ◽  
pp. C933-C940 ◽  
Author(s):  
J. S. Zheng ◽  
A. Christie ◽  
M. N. Levy ◽  
A. Scarpa
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ventricular Myocytes ◽  
Cell Voltage ◽  
Extracellular Atp ◽  
Camp Level ◽  
Intracellular Camp ◽  
Beta Adrenergic ◽  
Kinase C ◽  
Integrated Response

Activation of protein kinase C (PKC) modulates the mobilization of intracellular Ca2+ induced by extracellular ATP in rat ventricular myocytes. Pretreatment of myocytes with PKC activators attenuated both the ATP-induced Ca2+ transient and the noradrenergic potentiation of the Ca2+ response. Various PKC activators decreased both the basal cAMP level and the cAMP levels that had been elevated by norepinephrine, forskolin, or 3-isobutyl-1-methylxanthine. The inhibitory effects of PKC activators were reversed by the PKC inhibitor staurosporine. The ATP-induced Ca2+ response is an integrated response resulting from ATP eliciting an inward cation current (IATP), cellular depolarization, Ca2+ influx through Ca2+ channels, and Ca2+ release from the sarcoplasmic reticulum. We used the whole cell voltage-clamp technique to investigate which steps of this integrated response are affected by PKC. PKC activators did not significantly affect the IATP. In contrast, PKC activators decreased the basal Ca2+ current (ICa) or Ba2+ current and the beta-adrenergic-stimulated ICa. These results suggest that PKC-induced suppression of the ATP-induced Ca2+ response and the beta-adrenergic-potentiated Ca2+ response is achieved at least partially by decreasing the intracellular cAMP level and ICa.

Immunocytochemical evaluation of protein kinase C translocation to the inner nuclear matrix in 3T3 mouse fibroblasts after IGF-I treatment

1995 ◽  
Vol 103 (6) ◽  
pp. 447-457 ◽  
Author(s):  
N. Zini ◽  
A. M. Martelli ◽  
L. M. Neri ◽  
A. Bavelloni ◽  
P. Sabatelli ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Nuclear Matrix ◽  
Mouse Fibroblasts ◽  
Kinase C ◽  
Igf I

scholarly journals Extracellular ATP stimulates the early growth response protein 1 (Egr-1) via a protein kinase C-dependent pathway in the human osteoblastic HOBIT cell line

2003 ◽  
Vol 373 (3) ◽  
pp. 815-824 ◽  
Author(s):  
Alex PINES ◽  
Milena ROMANELLO ◽  
Laura CESARATTO ◽  
Giuseppe DAMANTE ◽  
Luigi MORO ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Response ◽  
Cytosolic Calcium ◽  
Early Growth ◽  
Extracellular Atp ◽  
Extracellular Nucleotides ◽  
Cell Physiology ◽  
Early Growth Response ◽  
Kinase C

Extracellular nucleotides exert an important role in controlling cell physiology by activating intracellular signalling cascades. Osteoblast HOBIT cells express P2Y1 and P2Y2 G-protein-coupled receptors, and respond to extracellular ATP by increasing cytosolic calcium concentrations. Early growth response protein 1 (Egr-1) is a C2H2-zinc-finger-containing transcriptional regulator responsible for the activation of several genes involved in the control of cell proliferation and apoptosis, and is thought to have a central role in osteoblast biology. We show that ATP treatment of HOBIT cells increases Egr-1 protein levels and binding activity via a mechanism involving a Ca2+-independent protein kinase C isoform. Moreover, hypotonic stress and increased medium turbulence, by inducing ATP release, result in a similar effect on Egr-1. Increased levels of Egr-1 protein expression and activity are achieved at very early times after stimulation (5 min), possibly accounting for a rapid way for changing the osteoblast gene-expression profile. A target gene for Egr-1 that is fundamental in osteoblast physiology, COL1A2, is up-regulated by ATP stimulation of HOBIT cells in a timescale that is compatible with that of Egr-1 activation.

Extracellular atp induces c-fos expression through elevation of [Ca2+]i independently of protein kinase C activation

Bone ◽  
1995 ◽  
Vol 17 (6) ◽  
pp. 559
Author(s):  
W.B. Bowler ◽  
C.J. Dixon ◽  
C. Halleux ◽  
R.A. Hipskind ◽  
W.D. Fraser ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Extracellular Atp ◽  
Kinase C ◽  
Fos Expression ◽  
Protein Kinase C Activation

Extracellular ATP-induced regulation of epidermal growth factor signaling in cultured renal LLC-PK1 cells

1993 ◽  
Vol 264 (4) ◽  
pp. C956-C960 ◽  
Author(s):  
H. Harada ◽  
H. Tai ◽  
A. Motomura ◽  
S. Suzuki ◽  
Y. Suketa
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Epidermal Growth Factor ◽  
Phospholipase C ◽  
Extracellular Atp ◽  
Egf Receptors ◽  
Kinase C ◽  
Epidermal Growth ◽  
Stimulation Of

We investigated the effect of extracellular ATP on the interaction of epidermal growth factor (EGF) with its receptor in cultured renal epithelial cells, LLC-PK1. Pretreatment with ATP, but not adenosine, inhibited the binding of 125I-labeled EGF. The inhibition demonstrated by ATP resulted from a decrease in the affinity of EGF receptors for its ligand, with no change in the number of EGF receptors. Incubation of phorbol 12-myristate 13-acetate (PMA) for 30 min mimicked the ATP-mediated inhibition. On the other hand, prolonged pretreatment with PMA, which leads to disappearance of protein kinase C activity, reversed the inhibition. In addition, pretreatment with the protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine prevented the ATP-mediated inhibition. ATP triggered an increase in inositol 1,4,5-trisphosphate levels and translocation of protein kinase C from cytosol to membranes, consist with the stimulation of phospholipase C and the activation of protein kinase C. These results demonstrate that extracellular ATP attenuates the ligand binding affinity of EGF receptor via the stimulation of phospholipase C, leading to the activation of protein kinase C in the LLC-PK1 cells.

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