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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
1-Monooleoylglycerol (MOG), a recently reported diacylglycerol kinase inhibitor (Bishop, W. R., Ganong, B. R., and Bell, R. M. (1986) J. Biol. Chem. 261, 6993-7000), exerts potent stimulatory effects on [3H]thymidine incorporation into DNA and glucose transport in Swiss 3T3 fibroblasts. MOG induces a rapid and sustained 2.5-fold increase in the cellular 1,2-diacylglycerol (1,2-DG) content, and phosphorylation of an acidic 80-kDa protein, a putative substrate for the protein kinase C (Ca2+/phospholipid-dependent
protein kinase
). The effect of MOG is additive to that of bombesin in terms of both an increase in tissue diacylglycerol content and phosphorylation of the 80-kDa proteins. In addition to these effects, MOG potently stimulates release of arachidonic acid from phospholipids. Inhibitors of cyclooxygenase and
lipoxygenase
have little effect, if any, on MOG-induced stimulation of glucose transport and DNA synthesis, while exogenously applied arachidonic readily stimulates both of these cellular responses. Furthermore, arachidonic acid, at its biologically active concentrations, is found to induce a rapid and sustained increase in cellular 1,2-DG content and stimulate the phosphorylation of the 80-kDa protein, although to a lesser extent than MOG. Prolonged pretreatment of the cells with phorbol 12,13-dibutyrate, which reduces the cellular protein kinase C content, markedly attenuates the effects of both MOG and arachidonic acid on glucose transport and DNA synthesis. These data indicate that MOG increases endogenous 1,2-DG content and thereby acts as a potent activator of protein kinase C, and that activation of protein kinase C is a crucial step in MOG-induced stimulation of mitogenesis and glucose transport.
...
PMID:Stimulation of mitogenesis and glucose transport by 1-monooleoylglycerol in Swiss 3T3 fibroblasts. 313 67
The 30 000 g precipitate of homogenized rat placenta was incubated with 32P-adenosine triphosphate (ATP); several endogenous proteins were specifically phosphorylated in the presence of 0.5 mM calcium and phosphatidylserine (105K protein at mid pregnancy, and 78K protein at the latter part of pregnancy). The calcium- and phospholipid-dependent
protein kinase
activity in the 30 000 g precipitate was six times greater than the activity in the supernatant fraction. The total protein kinase C activity in the precipitate was considerably greater at the end of pregnancy than it was at mid pregnancy. Diethylaminoethyl cellulose-purified membrane-bound protein kinase C was slightly inhibited by inhibitors of
lipoxygenase
, NDGA or ETYA, but not by SHAM or BW755C. Haemin and polylysine strongly inhibited this activity.
...
PMID:Phosphorylation of placental membrane proteins by a calcium- and phospholipid-dependent protein kinase. 370 32
Gonadotropin-releasing hormone agonist (GnRHa) markedly increased testosterone formation from 2.35 +/- 0.13 ng/ml of the controls to 14.92 +/- 0.33 ng/ml (mean +/- SE) in isolated and purified rat Leydig cells. GnRHa-induced testosterone formation was completely blocked by phospholipase A2 inhibitor (chloroquin, 10(-4) M), but was potentiated by the addition of either cyclo-oxygenase inhibitor (indomethacin) or
lipoxygenase
inhibitor (nordihydroguaiaretic acid, NDGA). Arachidonic acid also directly stimulated Leydig cell steroidogenesis and activated Ca/phospholipid dependent
protein kinase
. Steroidogenic effects of arachidonic acid were also potentiated by the addition of either indomethacin or NDGA. These results suggest that arachidonic acid may be important in mediating direct stimulatory effects of GnRH on Leydig cell steroidogenesis, and the conversion of arachidonic acid to either prostaglandins or leukotrienes is not required for its steroidogenic effect.
...
PMID:Mechanism of action of gonadotropin-releasing hormone stimulated Leydig cell steroidogenesis. III. The role of arachidonic acid and calcium/phospholipid dependent protein kinase. 392 Apr 63
Treatment of newborn murine epidermal cells with phospholipase C results in the generation of a chemiluminescence response similar to that previously described for phorbol ester tumor promoters. Based on inhibitor studies, the oxidant, believed to be superoxide anion, is most likely generated from
lipoxygenase
metabolism of arachidonic acid. The specificity of the response to phospholipase C from C. perfringens and not from B. cereus or phospholipase A2 suggests specific phospholipids are involved. The response observed appears to arise from the phospholipid-
protein kinase
c model for phorbol ester binding and activity.
...
PMID:Phospholipase C mimics tumor promoter-induced chemiluminescence in murine epidermal cells. 405 80
The mechanisms by which endothelium-dependent relaxants and nitrovasodilators cause relaxation of vascular smooth muscle has been reviewed. A model explaining these observations is summarized in Fig. 1. The endothelium-dependent vasodilators through interaction with their appropriate receptors are thought to activate phospholipase A2 and cause the release of an unsaturated fatty acid. The released unsaturated fatty acid or a metabolite is thought to be the "endothelial relaxant factor" that interacts with the smooth muscle component to cause relaxation. While the unsaturated fatty acid may be oxidized in either the endothelial cell or smooth muscle cell, the lability of the endothelial relaxant factor suggests that at least some of this processing occurs before its release from the endothelium. the model in Figure 1 suggests that an oxidized fatty acid or a derived free radical is responsible for activation of smooth muscle guanylate cyclase and increases in cyclic GMP levels. As pointed out above, the use of various inhibitors of fatty acid release and metabolism has not allowed us or others to predict the structure of the active material. To date the best evidence suggests that the unsaturated fatty acid is a product of either the
lipoxygenase
or P-450 pathways. Nitrovasodilators are thought to form nitric oxide free radical and directly activate guanylate cyclase as described above. Activated guanylate cyclase, whether by endothelium dependent agents or the nitrovasodilators, then increases the formation of cyclic GMP, which activates cyclic GMP-dependent
protein kinase
. The phosphorylation state of various proteins is then altered and, eventually, myosin light chain is dephosphorylated and relaxation occurs. Whether this mechanism involves cyclic GMP-dependent changes in activities of myosin light chain kinase and/or myosin light chain phosphatase remains to be determined. Although the altered phosphorylation state of myosin light chain that results from cyclic GMP accumulation may explain the mechanisms of action of cyclic GMP in smooth muscle relaxation, other mechanisms can not be excluded. For example, some additional studies which we have not summarized here indicate that the integrity of the membrane and Na+-K+ pump can modify both cyclic GMP synthesis and relaxation in rat aorta (38 and unpublished observations). Apparently complex interactions may exist in smooth muscle and other tissues which regulate cyclic GMP accumulation and/or its expression on some process. While several functions for cyclic GMP have been suggested, there is considerable evidence which suggests that one of its roles is relaxation of airway and vascular smooth muscle.
...
PMID:Endothelium-dependent and nitrovasodilator-induced relaxation of vascular smooth muscle: role of cyclic GMP. 614 63
Calcium- and phospholipid-dependent
protein kinase
(Ca, PL-PK) activity is detectable in mouse epidermis cytosol. It can be stimulated in vitro by complete and incomplete tumor promoters (12-0-tetradecanoylphorbol-13-acetate (TPA) and 12-0-retinoylphorbol-13-acetate (RPA], respectively. Effective inhibition of the enzyme activity is achieved with quercetin and phloretin, whereas the
lipoxygenase
and cyclooxygenase inhibitors nordihydroguaiaretic acid (NDGA) and esculetin show just weak or no inhibition. Quercetin inhibits the
lipoxygenase
and cyclooxygenase equally well as the Ca, PL-PK, whereas the strong Ca, PL-PK inhibitor phloretin is absolutely ineffective in inhibiting the
lipoxygenase
/cyclooxygenase. The application of these inhibitors in differentiating tumor promoter induced effects in vivo is proposed.
...
PMID:Calcium and phospholipid-dependent protein kinase activity in mouse epidermis cytosol. Stimulation by complete and incomplete tumor promoters and inhibition by various compounds. 623 97
Arachidonic acid metabolites have been implicated in the regulation of ACTH secretion. To define further which eicosanoid(s) is primarily involved, we examined the effects of both inhibitors of the three arachidonate metabolic pathways (cyclooxygenase,
lipoxygenase
, and epoxygenase) and specific eicosanoid products on ACTH secretion by rat pituitary corticotrophs in a microperifusion system. CRF stimulates sustained ACTH release that is mediated by
protein kinase
-A-induced extracellular Ca2+ (Cae2+) influx via L-type voltage-sensitive calcium channels (VSCC). Arginine vasopressin (AVP) stimulates an initial spike phase of ACTH release that presumably is mediated by inositol 1,4,5-trisphosphate-induced intracellular Ca2+ (Cai2+) release, followed by a sustained plateau phase of ACTH release that is mediated by
protein kinase
-C-induced Cae2+ influx via L-type VSCC. Pretreatment for 15 min with the
lipoxygenase
inhibitor nordihydroguaiaretic acid (NDGA; 50 microM), but not the cyclooxygenase inhibitor indomethacin (10 microM) or the epoxygenase inhibitor SKF525A (100 microM) inhibited the sustained response to CRF by 48% and the initial spike response to AVP by 38%. NDGA-induced inhibition was not reversed by indomethacin or SKF525A, alone or in combination, precluding arachidonate shunting into other pathways. However, the results suggested that epoxygenase metabolites may have a minor stimulatory and cyclooxygenase metabolites may have a minor inhibitory effect on ACTH secretion. Preexposure to NDGA suppressed by 43% the sustained response to 8-bromo-cAMP, which directly activates
protein kinase
-A; by 57% the sustained response to dioctanolglycerol, which directly activates
protein kinase
-C; and by 59% the spike-type response to ionomycin, which releases Cai2+ by an inositol 1,4,5-trisphosphate-independent mechanism. These results suggest that NDGA either inhibits the production of a
lipoxygenase
metabolite involved in Cae2+ influx and/or Cai2+ release or acts other than by inhibiting
lipoxygenase
, such as by directly blocking membrane transport of Cae2+. The three major
lipoxygenase
metabolites tested, 5(S)-, 12(S)-, and 15(S)-hydroxyeicosatetraenoic acid (HETE), all stimulated sustained ACTH release in a dose-dependent manner. At a concentration of 2 microM, 12(S)-HETE was 4.7 and 2.5 times more potent than 5(S)- and 15(S)-HETE, respectively, and completely reversed NDGA inhibition of both CRF- and AVP-stimulated ACTH secretion. The ACTH-releasing activity of 12(S)-HETE was inhibited 26% by removing Cae2+ and 54% by both removing Cae2+ and depleting Cai2+, indicating either that 12(S)-HETE facilitates transmembrane Ca2+ transfer or that increased cytosolic Ca2+ is necessary for 12(S)-HETE's action.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Role of lipoxygenase metabolites of arachidonic acid in the regulation of adrenocorticotropin secretion by perifused rat anterior pituitary cells. 752
We have investigated the regulatory role of PGI2 and its stable analogs, i.e., iloprost and cicaprost, on 12(S)-HETE- and TPA-enhanced tumor cell integrin expression and adhesion. Walker 256 carcinosarcoma cells express alpha IIb beta 3 integrin receptors, which mediate their adhesion to endothelium, subendothelial matrix and fibronectin. Adhesion is enhanced by treatment with exogenous 12(S)-HETE but not 12(R)-HETE or other
lipoxygenase
-derived hydroxy fatty acids, as well as by TPA. Both 12(S)-HETE and TPA enhanced alpha IIb beta 3 expression on W256 cells. PGI2 iloprost and cicaprost inhibited both 12(S)-HETE- and TPA-enhanced adhesion to endothelium and subendothelial matrix as well as alpha IIb beta 3 expression on W256 cells. The mechanism responsible for the effect of PGI2 was explored. Prostacyclin treatment of W256 cells resulted in an enhanced production of cAMP in a time- and dose-dependent manner. Pre-treatment of tumor cells with increasing concentrations of adenosine resulted in a dose-dependent decrease in the PGI2 effect on TPA or 12(S)-HETE-enhanced adhesion, suggesting that the PGI2 effect is mediated through
PKA
. Dibutyryl cAMP also blocked the 12(S)-HETE- or TPA-enhanced adhesion, and adenosine pre-treatment did not result in an inhibition of the dibutyryl cAMP effect. Collectively, our results suggest that the cyclooxygenase metabolite PGI2 can antagonize the
lipoxygenase
metabolite 12(S)-HETE- and TPA-enhanced alpha IIb beta 3 expression and tumor cell adhesion via activation of adenylate cyclase and elevation of intracellular levels of cAMP.
...
PMID:Inhibition of TPA and 12(S)-HETE-stimulated tumor cell adhesion by prostacyclin and its stable analogs: rationale for their antimetastatic effects. 753 Feb 35
The present study investigated the mechanisms involved in the mitogenic action of epidermal growth factor (EGF) in cultured human myometrial smooth muscle cells. The cells contained EGF/transforming growth factor-alpha (TGF-alpha) receptors as well as EGF and TGF-alpha mRNA transcripts and the corresponding proteins. Culturing with human EGF resulted in concentration- and time-dependent increases in cell density. The maximal increase was seen at 1 nM followed by a decrease to control levels at 100 nM EGF. The EGF increased cell density from 4 to 8 days followed by a plateau coinciding with the cells reaching confluence. EGF treatment concomitantly decreased the average size of cells. TGF-alpha mimicked EGF and there was no synergism between the two, suggesting a common mechanism of action. Although the presence of 10% fetal bovine serum enhanced overall cell growth, it was not required for EGF and TGF-alpha action. The receptor antibody, which is directed against the extracellular domain and can inhibit ligand binding to the receptors, dramatically inhibited the basal cell growth and exogenous EGF reversed the antibody effect. While TGF-alpha antibody was only marginally effective, EGF antibody had no effect on basal cell growth. Lavendustin (a tyrosine kinase inhibitor), calphostin (a protein kinase C inhibitor), but not H-89 (a
protein kinase A
inhibitor), inhibited EGF action. Indomethacin, a cyclo-oxygenase inhibitor, completely inhibited, whereas nordihydroguaiaretic acid, a
lipoxygenase
inhibitor, slightly inhibited EGF action. While estradiol-17 beta modestly inhibited basal as well as EGF-stimulated myometrial smooth muscle cell density, progesterone had no effect. In summary, mitogenic action of EGF in human myometrial smooth muscle cells does not require serum components and it involves tyrosine kinase and protein kinase C signaling and eicosanoids from the cyclooxygenase pathway of arachidonic acid metabolism.
...
PMID:Analysis of epidermal growth factor action in human myometrial smooth muscle cells. 756 38
Migration of astrocytes is thought to play a role in nerve regeneration and to be mediated, at least in part, by inflammation-associated cytokines. Plasminogen activators are secreted proteases that function in fibrinolysis and participate in cellular migration and invasion and, in some cases, are modulated by cytokines. Here, we show that two cytokines, tumor necrosis factor-alpha and interleukin-1 beta, can modulate plasminogen activation in astrocytes, each causing 90% reduction of total plasminogen activator activity. Direct and reverse zymography indicated that this reduction resulted from two simultaneous events, a pronounced decrease in tissue-type plasminogen activator activity and an induction of plasminogen activator inhibitor-1. Northern hybridization analysis indicated a 30-fold increase of the steady-state level of plasminogen activator inhibitor-1 mRNA following treatment with each of the two cytokines. Both of the cytokine-induced effects could be blocked by cycloheximide or actinomycin D. When signal transduction pathways were blocked, the results indicated the involvement of reduction in cyclic AMP levels,
protein kinase
activity, and arachidonic metabolites of the
lipoxygenase
pathway. The results thus show that the two cytokines reduce the ability of astrocytes to conduct fibrinolysis and extracellular proteolysis, and suggest that the effect of these cytokines on members of the plasminogen activation system is through a common signal transduction pathway.
...
PMID:Components of the plasminogen activator system in astrocytes are modulated by tumor necrosis factor-alpha and interleukin-1 beta through similar signal transduction pathways. 756 46
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