scholarly journals p44/42 mitogen-activated protein kinase is involved in the expression of ornithine decarboxylase in leukaemia L1210 cells

1999 ◽  
Vol 341 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Flavio FLAMIGNI ◽  
Annalisa FACCHINI ◽  
Cristina CAPANNI ◽  
Claudio STEFANELLI ◽  
Benedetta TANTINI ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Ornithine Decarboxylase ◽  
Positive Impact ◽  
Mitogen Activated Protein Kinase ◽  
Lower Sensitivity ◽  
Mapk Phosphorylation ◽  
L1210 Cells ◽  
Signal Transduction Inhibitors ◽  
Mitogen Activated Protein

The involvement of p44/42 mitogen-activated protein kinase (MAPK) in the induction of ornithine decarboxylase (ODC) was investigated by using PD98059, a specific MAPK-kinase (MEK1/2) inhibitor, and other signal-transduction inhibitors. In D,L-α-difluoromethylornithine (DFMO)-resistant L1210 cells stimulated to grow from quiescence, treatment with PD98059 inhibited p44/42 MAPK phosphorylation and the induction of ODC activity and protein. A marked reduction of the accumulation of mature ODC mRNA and its intron-containing precursor was observed, whereas ODC turnover was hardly affected. PD98059 also reduced the content of antizyme, but not that of antizyme mRNA. U0126, a novel and more potent inhibitor of MEK1/2, provoked a dose-dependent inhibition of ODC induction at lower concentrations with respect to PD98059. Other effective inhibitors of ODC induction proved to be genistein, manumycin A, herbimycin A, LY294002, wortmannin and KT5823, suggesting the involvement of other key proteins of signal-transduction pathways, i.e. Ras, Src, phosphatidylinositol 3-kinase and cGMP-dependent protein kinase, which may have a positive impact on MAPK. Cells kept in a DFMO-free medium, and thus containing high levels of putrescine and spermidine, showed enhanced MAPK phosphorylation and lower sensitivity to PD98059, compared with cells maintained in the presence of DFMO. In conclusion, these results indicate that the activation of p44/42 MAPK may favour the expression of ODC, and that polyamines, in turn, may affect the phosphorylation state of MAPK.

scholarly journals p44/42 mitogen-activated protein kinase is involved in the expression of ornithine decarboxylase in leukaemia L1210 cells

1999 ◽  
Vol 341 (2) ◽  
pp. 363 ◽  
Author(s):  
Flavio FLAMIGNI ◽  
Annalisa FACCHINI ◽  
Cristina CAPANNI ◽  
Claudio STEFANELLI ◽  
Benedetta TANTINI ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Ornithine Decarboxylase ◽  
Mitogen Activated Protein Kinase ◽  
L1210 Cells ◽  
Mitogen Activated Protein

Regulation of spontaneous and induced resumption of meiosis in mouse oocytes by different intracellular pathways

Reproduction ◽  
2000 ◽  
pp. 377-383 ◽  
Author(s):  
L Leonardsen ◽  
A Wiersma ◽  
M Baltsen ◽  
AG Byskov ◽  
CY Andersen
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Mitogen Activated Protein Kinase ◽  
Meiotic Maturation ◽  
Mouse Oocytes ◽  
Mitogen Activated Protein ◽  
Dependent Signal ◽  
Kinase Pathway ◽  
Kinase A

The mitogen-activated protein kinase-dependent and the cAMP-protein kinase A-dependent signal transduction pathways were studied in cultured mouse oocytes during induced and spontaneous meiotic maturation. The role of the mitogen-activated protein kinase pathway was assessed using PD98059, which specifically inhibits mitogen-activated protein kinase 1 and 2 (that is, MEK1 and MEK2), which activates mitogen-activated protein kinase. The cAMP-dependent protein kinase was studied by treating oocytes with the protein kinase A inhibitor rp-cAMP. Inhibition of the mitogen-activated protein kinase pathway by PD98059 (25 micromol l(-1)) selectively inhibited the stimulatory effect on meiotic maturation by FSH and meiosis-activating sterol (that is, 4,4-dimethyl-5alpha-cholest-8,14, 24-triene-3beta-ol) in the presence of 4 mmol hypoxanthine l(-1), whereas spontaneous maturation in the absence of hypoxanthine was unaffected. This finding indicates that different signal transduction mechanisms are involved in induced and spontaneous maturation. The protein kinase A inhibitor rp-cAMP induced meiotic maturation in the presence of 4 mmol hypoxanthine l(-1), an effect that was additive to the maturation-promoting effect of FSH and meiosis-activating sterol, indicating that induced maturation also uses the cAMP-protein kinase A-dependent signal transduction pathway. In conclusion, induced and spontaneous maturation of mouse oocytes appear to use different signal transduction pathways.

Far1 and Fus3 link the mating pheromone signal transduction pathway to three G1-phase Cdc28 kinase complexes

1993 ◽  
Vol 13 (9) ◽  
pp. 5659-5669 ◽  
Author(s):  
M Tyers ◽  
B Futcher
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Signal Transduction Pathway ◽  
Mitogen Activated Protein Kinase ◽  
G1 Phase ◽  
Transduction Pathway ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alpha Factor ◽  
Mitogen Activated Protein

In the yeast Saccharomyces cerevisiae, the Cdc28 protein kinase controls commitment to cell division at Start, but no biologically relevant G1-phase substrates have been identified. We have studied the kinase complexes formed between Cdc28 and each of the G1 cyclins Cln1, Cln2, and Cln3. Each complex has a specific array of coprecipitated in vitro substrates. We identify one of these as Far1, a protein required for pheromone-induced arrest at Start. Treatment with alpha-factor induces a preferential association and/or phosphorylation of Far1 by the Cln1, Cln2, and Cln3 kinase complexes. This induced interaction depends upon the Fus3 protein kinase, a mitogen-activated protein kinase homolog that functions near the bottom of the alpha-factor signal transduction pathway. Thus, we trace a path through which a mitogen-activated protein kinase regulates a Cdc2 kinase.

HSP27 in signal transduction and association with contractile proteins in smooth muscle cells

1999 ◽  
Vol 277 (2) ◽  
pp. G445-G454 ◽  
Author(s):  
Adenike I. Ibitayo ◽  
Jeanette Sladick ◽  
Sony Tuteja ◽  
Otto Louis-Jacques ◽  
Hirotaka Yamada ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Muscle Contraction ◽  
Smooth Muscle Contraction ◽  
Contractile Proteins ◽  
Mitogen Activated Protein Kinase ◽  
Signal Transduction Cascade ◽  
Kinase C ◽  
Mitogen Activated Protein

Sustained smooth muscle contraction is mediated by protein kinase C (PKC) through a signal transduction cascade leading to contraction. Heat-shock protein 27 (HSP27) appears to be the link between these two major events, i.e., signal transduction and sustained smooth muscle contraction. We have investigated the involvement of HSP27 in signal transduction and HSP27 association with contractile proteins (e.g., actin, myosin, tropomyosin, and caldesmon) resulting in sustained smooth muscle contraction. We have carried out confocal microscopy to investigate the cellular reorganization and colocalization of proteins and immunoprecipitation of HSP27 with actin, myosin, tropomyosin, and caldesmon as detected by sequential immunoblotting. Our results indicate that 1) translocation of Raf-1 to the membrane when stimulated with ceramide is inhibited by vasoactive intestinal peptide (VIP), a relaxant neuropeptide; 2) PKC-α and mitogen-activated protein kinase translocate and colocalize on the membrane in response to ceramide, and PKC-α translocation is inhibited by VIP; 3) HSP27 colocalizes with actin when contraction occurs; and 4) HSP27 immunoprecipitates with actin and with the contractile proteins myosin, tropomyosin, and caldesmon. We propose a model in which HSP27 is involved in sustained smooth muscle contraction and modulates the interaction of actin, myosin, tropomyosin, and caldesmon.

scholarly journals Differential Activation of Mitogen-Activated Protein Kinase Pathways after Traumatic Brain Injury in the Rat Hippocampus

2002 ◽  
Vol 22 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Naoki Otani ◽  
Hiroshi Nawashiro ◽  
Shinji Fukui ◽  
Namiko Nomura ◽  
Akiko Yano ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Protein Kinase ◽  
Pyramidal Cell ◽  
Pyramidal Neurons ◽  
Rat Hippocampus ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Cell Layers

Mitogen-activated protein kinases, which play a crucial role in signal transduction, are activated by phosphorylation in response to a variety of mitogenic signals. In the present study, the authors used Western blot analysis and immunohistochemistry to show that phosphorylated extracellular signal-regulated protein kinase (p-ERK) and c-Jun NH(2)-terminal kinase (p-JNK), but not p38 mitogen-activated protein kinase, significantly increased in both the neurons and astrocytes after traumatic brain injury in the rat hippocampus. Different immunoreactivities of p-ERK and p-JNK were observed in the pyramidal cell layers and dentate hilar cells immediately after traumatic brain injury. Immunoreactivity for p-JNK was uniformly induced but was only transiently induced throughout all pyramidal cell layers. However, strong immunoreactivity for p-ERK was observed in the dentate hilar cells and the damaged CA3 neurons, along with the appearance of pyknotic morphologic changes. In addition, immunoreactivity for p-ERK was seen in astrocytes surrounding dentate and CA3 pyramidal neurons 6 hours after traumatic brain injury. These findings suggest that ERK and JNK but not p38 cascades may be closely involved in signal transduction in the rat hippocampus after traumatic brain injury.

scholarly journals The TGFβ-induced phosphorylation and activation of p38 mitogen-activated protein kinase is mediated by MAP3K4 and MAP3K10 but not TAK1

Open Biology ◽  
2013 ◽  
Vol 3 (6) ◽  
pp. 130067 ◽  
Author(s):  
Gopal P. Sapkota
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
Mesenchymal Transition ◽  
Mitogen Activated Protein

The signalling pathways downstream of the transforming growth factor beta (TGFβ) family of cytokines play critical roles in all aspects of cellular homeostasis. The phosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) has been implicated in TGFβ-induced epithelial-to-mesenchymal transition and apoptosis. The precise molecular mechanisms by which TGFβ cytokines induce the phosphorylation and activation of p38 MAPK are unclear. In this study, I demonstrate that TGFβ-activated kinase 1 (TAK1/MAP3K7) does not play a role in the TGFβ-induced phosphorylation and activation of p38 MAPK in MEFs and HaCaT keratinocytes. Instead, RNAi -mediated depletion of MAP3K4 and MAP3K10 results in the inhibition of the TGFβ-induced p38 MAPK phosphorylation. Furthermore, the depletion of MAP3K10 from cells homozygously knocked-in with a catalytically inactive mutant of MAP3K4 completely abolishes the TGFβ-induced phosphorylation of p38 MAPK, implying that among MAP3Ks, MAP3K4 and MAP3K10 are sufficient for mediating the TGFβ-induced activation of p38 MAPK.

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