scholarly journals A novel protein kinase C  -dependent signal to ERK1/2 activated by  V 3 integrin in osteoclasts and in Chinese hamster ovary (CHO) cells

2005 ◽  
Vol 118 (15) ◽  
pp. 3263-3275 ◽  
Author(s):  
N. Rucci
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Kinase C ◽  
Dependent Signal ◽  
Novel Protein

scholarly journals Acceleration of Sodium-Calcium Exchange Activity during ATP-induced Calcium Release in Transfected Chinese Hamster Ovary Cells

1997 ◽  
Vol 109 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Melissa Vázquez ◽  
Yu Fang ◽  
John P. Reeves
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chinese Hamster Ovary ◽  
Calcium Release ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Kinase C ◽  
Stimulation Of ◽  
Exchange Activity

The P2U purinergic agonist ATP (0.3 mM) elicited an increase in [Ca2+]i due to Ca2+ release from intracellular stores in transfected Chinese hamster ovary cells that express the bovine cardiac Na+/Ca2+ exchanger (CK1.4 cells). The following observations indicate that ATP-evoked Ca2+ release was accompanied by a Ca2+- dependent regulatory activation of Na+/Ca2+ exchange activity: Addition of extracellular Ca2+ (0.7 mM) 0–1 min after ATP evoked a dramatic rise in [Ca2+]i in Na+-free media (Li+ substitution) compared to Na+-containing media; no differences between Na+- and Li+-based media were observed with vector-transfected cells. In the presence of physiological concentrations of extracellular Na+ and Ca2+, the ATP-evoked rise in [Ca2+]i declined more rapidly in CK1.4 cells compared to control cells, but then attained a long-lived plateau of elevated [Ca2+]i which eventually came to exceed the declining [Ca2+]i values in control cells. ATP elicited a transient acceleration of exchange-mediated Ba2+ influx, consistent with regulatory activation of the Na+/Ca2+ exchanger. The acceleration of Ba2+ influx was not observed in vector-transfected control cells, or in CK1.4 cells in the absence of intracellular Na+ or when the Ca2+ content of the intracellular stores had been reduced by prior treatment with ionomycin. The protein kinase C activator phorbol 12-myristate 13-acetate attenuated the exchange-mediated rise in [Ca2+]i under Na+-free conditions, but did not inhibit the ATP-evoked stimulation of Ba2+ influx. The effects of PMA are therefore not due to inhibition of exchange activity, but probably reflect the influence of protein kinase C on other Ca2+ homeostatic mechanisms. We conclude that exchange activity is accelerated during ATP-evoked Ca2+ release from intracellular stores through regulatory activation by increased [Ca2+]i. In the absence of extracellular Ca2+, the stimulation of exchange activity is short-lived and follows the time course of the [Ca2+]i transient; in the presence of extracellular Ca2+, we suggest that the exchanger remains activated for a longer period of time, thereby stabilizing and prolonging the plateau phase of store-dependent Ca2+ entry.

Characterization of Tyrosine-Phosphorylated   Isoform of Protein Kinase C Isolated from Chinese Hamster Ovary Cells

1997 ◽  
Vol 121 (6) ◽  
pp. 1047-1053 ◽  
Author(s):  
M. Kadotani ◽  
T. Nishiuma ◽  
M. Nanahoshi ◽  
Y. Tsujishita ◽  
K. Ogita ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Kinase C

scholarly journals The WD protein Rack1 mediates protein kinase C and integrin-dependent cell migration

2001 ◽  
Vol 114 (9) ◽  
pp. 1691-1698 ◽  
Author(s):  
C.S. Buensuceso ◽  
D. Woodside ◽  
J.L. Huff ◽  
G.E. Plopper ◽  
T.E. O'Toole
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Scaffolding Protein ◽  
Kinase C ◽  
Bidirectional Signaling ◽  
Pkc Isoforms ◽  
Dependent Cell

The scaffolding protein, Rack1, is a seven-WD-domain-containing protein that has been implicated in binding to integrin (β) subunit cytoplasmic domains and to members of two kinase families (src and protein kinase C, PKC) that mediate integrin bidirectional signaling. To explore the role of Rack1 in integrin function we have transfected this protein in Chinese hamster ovary (CHO) cells. We have observed no effect of Rack1 overexpression on inside-out signaling as the ligand binding properties of CHO cells also expressing constitutively active or inactive integrins were not affected. In contrast, we observed that cells stably or transiently overexpressing Rack1 had decreased migration compared to mock transfected cells. Stable Rack1 transfectants also demonstrated an increased number of actin stress fibers and focal contacts. These effects on motility and cytoskeletal organization did not appear to result from Rack1 inhibition of src function as downstream substrates of this kinase were phosphorylated normally. In addition, expression of an active src construct did not reverse the migratory deficit induced by Rack1 overexpression. On the other hand when we overexpressed a Rack1 variant with alanine substitutions in the putative PKC binding site in its third WD domain, we observed no deficit in migration. Thus the ability of Rack1 to bind, localize and stabilize PKC isoforms is likely to be involved in aspects of integrin outside-in signaling.

scholarly journals Concerted action of cytosolic Ca2+ and protein kinase C in receptor-mediated phospholipase D activation in Chinese hamster ovary cells expressing the cholecystokinin-A receptor

1999 ◽  
Vol 337 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Remko R. BOSCH ◽  
Rolf L. L. SMEETS ◽  
Frank SLEUTELS ◽  
Anjana M. P. PATEL ◽  
Sjenet E. Van EMST-De VRIES ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Kinase C ◽  
Peptide Amide ◽  
Sustained Increase

Receptor-mediated activation of phosphatidylcholine phosphatidohydrolase or phospholipase D (PLD) was studied in Chinese hamster ovary (CHO) cells expressing the cholecystokinin-A (CCK-A) receptor. Cells were labelled with [3H]myristic acid for 24 h and PLD-catalysed [3H]phosphatidylethanol formation was measured in the presence of 1% (v/v) ethanol. Cholecystokinin-(26–33)-peptide amide (CCK8) increased PLD activity both time- and dose-dependently. Maximal activation of protein kinase C (PKC) with 1 µM PMA or sustained elevation of the cytosolic free Ca2+ concentration ([Ca2+]i) with 1 µM thapsigargin increased PLD activity to 50% and 70% of the maximal value obtained with CCK8 respectively. The stimulatory effects of CCK8, PMA and thapsigargin were abolished in cells in which PKC was downregulated or inhibited by chelerythrine. PMA/Ca2+-stimulated PLD activity was absent in a homogenate of PKC-downregulated cells but could be restored upon addition of purified rat brain PKC. CCK8-induced PLD activation was inhibited by 90% in the absence of external Ca2+, demonstrating that receptor-mediated activation of PKC in itself does not significantly add to PLD activation but requires a sustained increase in [Ca2+]i. Taken together, the results presented demonstrate that, in CHO-CCK-A cells, receptor-mediated PLD activation is completely dependent on PKC, but that the extent to which PLD becomes activated depends largely, if not entirely, on the magnitude and duration of the agonist-induced increase in [Ca2+]i.

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