Hydrolysis of phosphatidylcholine couples Ras to activation of Raf protein kinase during mitogenic signal transduction

1993 ◽  
Vol 13 (12) ◽  
pp. 7645-7651
Author(s):  
H Cai ◽  
P Erhardt ◽  
J Troppmair ◽  
M T Diaz-Meco ◽  
G Sithanandam ◽  
...  
Keyword(s):  
Growth Factors ◽  
Protein Kinase ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Expression Plasmid ◽  
Quiescent Cells ◽  
Mitogenic Signal Transduction ◽  
The Relationship ◽  
Hydrolysis Of ◽  
Mitogenic Signal

We have investigated the relationship between hydrolysis of phosphatidylcholine (PC) and activation of the Raf-1 protein kinase in Ras-mediated transduction of mitogenic signals. As previously reported, cotransfection of a PC-specific phospholipase C (PC-PLC) expression plasmid bypassed the block to cell proliferation resulting from expression of the dominant inhibitory mutant Ras N-17. In contrast, PC-PLC failed to bypass the inhibitory effect of dominant negative Raf mutants, suggesting that PC-PLC functions downstream of Ras but upstream of Raf. Consistent with this hypothesis, treatment of quiescent cells with exogenous PC-PLC induced Raf activation, even when normal Ras function was blocked by Ras N-17 expression. Further, activation of Raf in response to mitogenic growth factors was blocked by inhibition of endogenous PC-PLC. Taken together, these results indicate that hydrolysis of PC mediates Raf activation in response to mitogenic growth factors.

scholarly journals Hydrolysis of phosphatidylcholine couples Ras to activation of Raf protein kinase during mitogenic signal transduction.

1993 ◽  
Vol 13 (12) ◽  
pp. 7645-7651 ◽  
Author(s):  
H Cai ◽  
P Erhardt ◽  
J Troppmair ◽  
M T Diaz-Meco ◽  
G Sithanandam ◽  
...  
Keyword(s):  
Growth Factors ◽  
Protein Kinase ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Expression Plasmid ◽  
Quiescent Cells ◽  
Mitogenic Signal Transduction ◽  
The Relationship ◽  
Hydrolysis Of ◽  
Mitogenic Signal

We have investigated the relationship between hydrolysis of phosphatidylcholine (PC) and activation of the Raf-1 protein kinase in Ras-mediated transduction of mitogenic signals. As previously reported, cotransfection of a PC-specific phospholipase C (PC-PLC) expression plasmid bypassed the block to cell proliferation resulting from expression of the dominant inhibitory mutant Ras N-17. In contrast, PC-PLC failed to bypass the inhibitory effect of dominant negative Raf mutants, suggesting that PC-PLC functions downstream of Ras but upstream of Raf. Consistent with this hypothesis, treatment of quiescent cells with exogenous PC-PLC induced Raf activation, even when normal Ras function was blocked by Ras N-17 expression. Further, activation of Raf in response to mitogenic growth factors was blocked by inhibition of endogenous PC-PLC. Taken together, these results indicate that hydrolysis of PC mediates Raf activation in response to mitogenic growth factors.

Genistein but not staurosporine can inhibit the mitogenic signal evoked by lithium in rat thyroid cells (FRTL-5)

1994 ◽  
Vol 143 (2) ◽  
pp. 221-226 ◽  
Author(s):  
T Takano ◽  
K Takada ◽  
H Tada ◽  
S Nishiyama ◽  
N Amino
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Dna Synthesis ◽  
Thyroid Cells ◽  
Kinase C ◽  
Mitogenic Signal Transduction ◽  
Rat Thyroid ◽  
Mitogenic Signal

Abstract Long-term administration of lithium is one of the well-known causes of goiter. It can stimulate DNA synthesis in rat thyroid cells (FRTL-5) treated with thyroid-stimulating hormone (TSH). To investigate the mitogenic signal transduction system activated by lithium, lithium-induced DNA synthesis and Ca2+ influx were studied using two protein kinase inhibitors, genistein as a specific tyrosine kinase inhibitor and staurosporine as a potent inhibitor of protein kinase C. Genistein but not staurosporine blocked the DNA synthesis induced by lithium in TSH-primed cells but neither compound had any effect on the Ca2+ entry stimulated by lithium. Genistein clearly attenuated the phosphotyrosine content of the 175 kDa substrate in the presence of lithium but staurosporine failed to do so. Moreover, lithium could also stimulate DNA synthesis in protein kinase C down-regulated cells. These data demonstrate that lithium may require the activation of a particular genistein-sensitive kinase, possibly a tyrosine kinase, to induce cell proliferation. It is suggested that the phorbol ester-sensitive protein kinase C family might not participate in the mitogenic signal transduction pathway activated by lithium. Journal of Endocrinology (1994) 143, 221–226

Effect of a dominant inhibitory Ha-ras mutation on mitogenic signal transduction in NIH 3T3 cells

1990 ◽  
Vol 10 (10) ◽  
pp. 5314-5323
Author(s):  
H Cai ◽  
J Szeberényi ◽  
G M Cooper
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Dna Synthesis ◽  
3T3 Cells ◽  
Kinase C ◽  
Mitogenic Signal Transduction ◽  
Nih 3T3 ◽  
Mitogenic Signal

We used a dominant inhibitory mutation of c-Ha-ras which changes Ser-17 to Asn-17 in the gene product p21 [p21(Asn-17)Ha-ras] to investigate ras function in mitogenic signal transduction. An NIH 3T3 cell line [NIH(M17)] was isolated that displayed inducible expression of the mutant Ha-ras gene (Ha-ras Asn-17) via the mouse mammary tumor virus long terminal repeat and was growth inhibited by dexamethasone. The effect of dexamethasone induction on response of quiescent NIH(M17) cells to mitogens was then analyzed. Stimulation of DNA synthesis by epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) was completely blocked by p21(Asn-17) expression, and stimulation by serum, fibroblast growth factor, and platelet-derived growth factor was partially inhibited. However, the induction of fos, jun, and myc by EGF and TPA was not significantly inhibited in this cell line. An effect of p21(Asn-17) on fos induction was, however, demonstrated in transient expression assays in which quiescent NIH 3T3 cells were cotransfected with a fos-cat receptor plasmid plus a Ha-ras Asn-17 expression vector. In this assay, p21(Asn-17) inhibited chloramphenicol acetyltransferase expression induced by EGF and other growth factors. In contrast to its effect on DNA synthesis, however, Ha-ras Asn-17 expression did not inhibit fos-cat expression induced by TPA. Conversely, downregulation of protein kinase C did not inhibit fos-cat induction by activated ras or other oncogenes. These results suggest that ras proteins are involved in at least two parallel mitogenic signal transduction pathways, one of which is independent of protein kinase C. Although either pathway alone appears to be sufficient to induce fos, both appear to be necessary to induce the full mitogenic response.

Abstract 11302: Sevoflurane Pre-Conditioning Effectively Ameliorates Diabetic Myocardial Ischemia/Reperfusion Injury via Differential Regulation of p38 and ERK

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jianli Zhao ◽  
Jingjing Li ◽  
Rui Li ◽  
Liyuan Jiao ◽  
Yanqing Zhang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Myocardial Ischemia ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Ampk Signaling ◽  
Myocardial Ischemia Reperfusion

Diabetes (DB) significantly exacerbates myocardial ischemia/reperfusion (MI/R) injury. Unfortunately, conventional pre-conditioning (PreCon) provides diminished cardioprotection during DB, due partially to impaired AMP-activated protein kinase (AMPK) signaling. The current study investigated whether PreCon by inhaled anesthetic sevoflurane (SF-PreCon) remains protective in DB, and if so, to dissect the involved mechanisms. Non-diabetic (ND) or high-fat diet-induced DB mice were subjected to MI/R and randomized into control and SF-PreCon (3 cycles of 15 minute-exposures to 2% sevoflurane prior to MI) groups. As expected, SF-PreCon significantly reduced MI/R injury in ND mice. Importantly, SF-PreCon also significantly reduced MI/R injury in DB mice, as evidenced by reduced apoptosis (-23.1±1.6, P<0.01), decreased infarct size (-21.2±2.3%, P<0.01), and augmented cardiac function (+24±3.0%, P<0.01). To determine the role of AMPK in SF-PreCon-mediated cardioprotection, the effect of SF-PreCon upon MI/R injury was determined in cardiac specific AMPKα2 dominant negative overexpression mice (AMPK-DN). We demonstrate SF-PreCon remained cardioprotective in AMPK-DN mice. To explore the responsible molecular mechanisms, multiple cell-survival signaling molecules were screened. Interestingly, SF-PreCon differentially regulated mitogen-activated protein kinase (MAPK) family members in the MI/R heart. In ND mice, SF-PreCon dramatically reduced (-81±7.2%) MI/R-induced activation of p38, a pro-death MAPK, without significantly altering ERK and JNK. In DB and AMPK-DN mice, the inhibitory effect of SF-PreCon upon p38 activation was significantly blunted (DB: -8±2.1%) or virtually abolished (AMPK-DN). However, SF-PreCon significantly increased (P<0.05) phosphorylation of ERK1/2, a pro-survival MAPK. Collectively, we demonstrate SF-PreCon protected the heart via AMPK-dependent inhibition of pro-death MAPK in ND mice. However, SF-PreCon exerts its cardioprotective actions via AMPK-independent activation of pro-survival MAPK in DB mice. These results suggest SF-PreCon may be a superior intervention over conventional PreCon in DB patients, where AMPK signaling is impaired.

Protein kinase C ζ isoform is critical for mitogenic signal transduction

Cell ◽  
1993 ◽  
Vol 74 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Edurne Berra ◽  
Maria T. Diaz-Meco ◽  
Isabel Dominguez ◽  
Maria M. Municio ◽  
Laura Sanz ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Mitogenic Signal Transduction ◽  
Mitogenic Signal

scholarly journals A Role for p38 Stress-Activated Protein Kinase in Regulation of Cell Growth via TORC1

2009 ◽  
Vol 30 (2) ◽  
pp. 481-495 ◽  
Author(s):  
Megan Cully ◽  
Alice Genevet ◽  
Patricia Warne ◽  
Caroline Treins ◽  
Tao Liu ◽  
...  
Keyword(s):  
Growth Factors ◽  
Protein Kinase ◽  
Cell Growth ◽  
Ex Vivo ◽  
Dominant Negative ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Small Cells ◽  
Genetic Ablation ◽  
Mitogen Activated Protein

ABSTRACT The target of rapamycin (TOR) complex 1 (TORC1) signaling pathway is a critical regulator of translation and cell growth. To identify novel components of this pathway, we performed a kinome-wide RNA interference (RNAi) screen in Drosophila melanogaster S2 cells. RNAi targeting components of the p38 stress-activated kinase cascade prevented the cell size increase elicited by depletion of the TOR negative regulator TSC2. In mammalian and Drosophila tissue culture, as well as in Drosophila ovaries ex vivo, p38-activating stresses, such as H2O2 and anisomycin, were able to activate TORC1. This stress-induced TORC1 activation could be blocked by RNAi against mitogen-activated protein kinase kinase 3 and 6 (MKK3/6) or by the overexpression of dominant negative Rags. Interestingly, p38 was also required for the activation of TORC1 in response to amino acids and growth factors. Genetic ablation either of p38b or licorne, its upstream kinase, resulted in small flies consisting of small cells. Mutants with mutations in licorne or p38b are nutrition sensitive; low-nutrient food accentuates the small-organism phenotypes, as well as the partial lethality of the p38b null allele. These data suggest that p38 is an important positive regulator of TORC1 in both mammalian and Drosophila systems in response to certain stresses and growth factors.

scholarly journals Effect of a dominant inhibitory Ha-ras mutation on mitogenic signal transduction in NIH 3T3 cells.

1990 ◽  
Vol 10 (10) ◽  
pp. 5314-5323 ◽  
Author(s):  
H Cai ◽  
J Szeberényi ◽  
G M Cooper
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Dna Synthesis ◽  
3T3 Cells ◽  
Kinase C ◽  
Mitogenic Signal Transduction ◽  
Nih 3T3 ◽  
Mitogenic Signal

We used a dominant inhibitory mutation of c-Ha-ras which changes Ser-17 to Asn-17 in the gene product p21 [p21(Asn-17)Ha-ras] to investigate ras function in mitogenic signal transduction. An NIH 3T3 cell line [NIH(M17)] was isolated that displayed inducible expression of the mutant Ha-ras gene (Ha-ras Asn-17) via the mouse mammary tumor virus long terminal repeat and was growth inhibited by dexamethasone. The effect of dexamethasone induction on response of quiescent NIH(M17) cells to mitogens was then analyzed. Stimulation of DNA synthesis by epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) was completely blocked by p21(Asn-17) expression, and stimulation by serum, fibroblast growth factor, and platelet-derived growth factor was partially inhibited. However, the induction of fos, jun, and myc by EGF and TPA was not significantly inhibited in this cell line. An effect of p21(Asn-17) on fos induction was, however, demonstrated in transient expression assays in which quiescent NIH 3T3 cells were cotransfected with a fos-cat receptor plasmid plus a Ha-ras Asn-17 expression vector. In this assay, p21(Asn-17) inhibited chloramphenicol acetyltransferase expression induced by EGF and other growth factors. In contrast to its effect on DNA synthesis, however, Ha-ras Asn-17 expression did not inhibit fos-cat expression induced by TPA. Conversely, downregulation of protein kinase C did not inhibit fos-cat induction by activated ras or other oncogenes. These results suggest that ras proteins are involved in at least two parallel mitogenic signal transduction pathways, one of which is independent of protein kinase C. Although either pathway alone appears to be sufficient to induce fos, both appear to be necessary to induce the full mitogenic response.

Hydrolysis of phosphatidylcholine is stimulated by Ras proteins during mitogenic signal transduction

1992 ◽  
Vol 12 (12) ◽  
pp. 5329-5335
Author(s):  
H Cai ◽  
P Erhardt ◽  
J Szeberényi ◽  
M T Diaz-Meco ◽  
T Johansen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Growth Factor ◽  
Phorbol Esters ◽  
Ras Proteins ◽  
Mitogenic Signal Transduction ◽  
Nih 3T3 ◽  
Hydrolysis Of ◽  
Mitogenic Signal ◽  
Mitogenic Signals

We have used a dominant inhibitory ras mutant (Ha-ras Asn-17) to investigate the relationship of Ras proteins to hydrolysis of phosphatidylcholine (PC) in the transduction of mitogenic signals. Expression of Ha-Ras Asn-17 inhibited NIH 3T3 cell proliferation induced by polypeptide growth factors or phorbol esters. In contrast, the mitogenic activity of PC-specific phospholipase C (PC-PLC) was not inhibited by Ha-Ras Asn-17 expression. Similarly, cotransfection with a cloned PC-PLC gene bypassed the block to NIH 3T3 cell proliferation resulting from expression of the inhibitory ras mutant. Hydrolysis of PC can therefore induce cell proliferation in the absence of normal Ras activity, suggesting that PC-derived second messengers may act downstream of Ras in mitogenic signal transduction. This was substantiated by the finding that Ha-Ras Asn-17 expression inhibited growth factor-stimulated hydrolysis of PC. Taken together, these results indicate that PC hydrolysis is a target of Ras during the transduction of growth factor-initiated mitogenic signals.

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