EC:2.7.11.13 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.13 (protein kinase C)
49,245 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Drugs thought to inhibit the actions of protein kinase C (PKC) and cAMP dependent protein kinase (A-kinase) were infused intrathecally into the subarachnoid space of the lumbar region of the spinal cord, and the effects on acoustic startle were measured. Previous work has shown that intrathecal infusion of drugs thought to increase cAMP increase the startle response. The present experiment evaluated whether inhibition of A-kinase would prevent this effect. Rats were infused with the isoquinoline sulfonamide, H-8 (360 nmol) or vehicle (50% dimethyl sulfoxide), 30 min prior to infusion of 100 nmol of dibutyryl cAMP. By itself, H-8 had little effect on startle, but completely blocked the normal excitatory effect of dibutyryl cAMP on startle. In contrast, the isoquinoline sulfonamide, H-7, which is less active in blocking A-kinase, but more active in blocking PKC, did not block dibutyryl cAMP. Moreover, H-8 did not block the excitatory effect of intrathecal infusion of the 5-HT1A receptor agonist, 8-OH-dipropylaminotetraline (8-OH-DPAT). Thus, the blockade of dibutyryl cAMP by H-8 appears somewhat specific and suggests an involvement of A-kinase in the excitatory effects of dibutyryl cAMP on the acoustic startle response. In a second experiment, it was found that administration of the isoquinoline sulfonamide H-7 caused a marked, dose-dependent (150-800 nmol) facilitation of the startle reflex in comparison with its vehicle. Tris buffer (0.1 M). Like H-7, another PKC inhibitor, GT1b (20 nmol) produced a marked increase in the startle reflex versus its vehicle, 0.01 M phosphate buffer.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Blockade of the spinal excitatory effect of cAMP on the startle reflex by intrathecal administration of the isoquinoline sulfonamide H-8: comparison to the protein kinase C inhibitor H-7. 217 10

A recombinant N-ras oncogene, under the transcriptional control of a corticosteroid-inducible mouse mammary tumor virus (MMTV) promoter, has been stably transfected into a PC12 rat pheochromocytoma subline. This cell line, designated UR61, undergoes N-ras-induced neurite outgrowth and cessation of division when treated with dexamethasone (Guerrero et al.: Biochemical and Biophysical Research Communications 150:1185-1192, 1988). We have employed the UR61 cell line as a model for ras oncogene-induced neuronal differentiation. In UR61 cells, dexamethasone-induced expression of the recombinant N-ras gene resulted in time-dependent expression of ornithine decarboxylase enzyme (ODC) activity. Prompted by recent reports of possible functional (Lacal et al.: Molecular and Cellular Biology 7:4146-4149, 1987; Wolfman and Macara: Nature 325: 359-361, 1987) and direct (Jeng et al.: Biochemical and Biophysical Research Communications 145:782-788, 1987) interactions between oncogene ras-coded p21 and protein kinase C (PK-C; Ca++/phospholipid-dependent protein kinase), we employed the protein kinase inhibitor H-8 (N-[2-(methylamino)ethyl]-5-isoquinoline sulfonamide dihydrochloride) and phorbol 12,13-dibutyrate (PDBu) to investigate this putative interaction in the UR61 cells, where ODC activity and neurite outgrowth were used as indicators of oncogenic N-ras action. Treatment of UR61 cells with PDBu depleted cells of PK-C and failed to promote neurite outgrowth but enhanced N-ras-induced neurite outgrowth and ODC activity. H-8, which suppressed ODC induction by forskolin and phorbol myristate acetate, enhanced both N-ras-induced ODC activity and neurite outgrowth. Inhibition of ODC activity by difluoromethylornithine (DFMO) did not suppress oncogenic ras-induced neurite outgrowth, suggesting that these two ras-triggered events are mechanistically independent. These findings suggest that certain actions of N-ras can occur in cells depleted of PK-C, and thus, the role of PK-C in ras-induced differentiation differs from its role in ras-induced mitogenesis and transformation.
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PMID:Potentiation of oncogenic N-ras-induced neurite outgrowth and ornithine decarboxylase activity by phorbol dibutyrate and protein kinase inhibitor H-8. 218 Sep 65

Colony-stimulating factor 1 (CSF-1) is required for the survival, proliferation and differentiation of monocytes. We previously demonstrated that the CSF-1 receptor is linked to a pertussis toxin-sensitive G protein and that the induction of Na+ influx by CSF-1 is a pertussis toxin-sensitive event. The present studies have examined activation of protein kinase C as a potential intracellular signaling event induced by the activated CSF-1 receptor. The results demonstrate that CSF-1 stimulates translocation of protein kinase C activity from the cytosol to membrane fractions. This activation of protein kinase C was sensitive to pretreatment of the monocytes with pertussis toxin. Lipid distribution studies demonstrated that phosphatidylcholine (PC) is the major phospholipid in human monocytes. Moreover, the results indicate that CSF-1 stimulation is associated with decreases in PC, but not in phosphatidylinositol (PI), levels. The absence of an effect of CSF-1 on PI turnover was confirmed by the lack of changes in inositol phosphate production. In contrast, CSF-1 stimulation was associated with increased hydrolysis of PC to phosphorylcholine and diacylglycerol (DAG) in both intact monocytes and cell-free assays. Furthermore, the increase in PC turnover induced by CSF-1 was sensitive to pertussis toxin. The results also demonstrate that the induction of Na+ influx by CSF-1 is inhibited by the protein kinase C inhibitors staurosporine and the isoquinoline derivative H7, but not by HA1004.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Colony-stimulating factor 1 activates protein kinase C in human monocytes. 219 73

Phorbol 12,13-dibutyrate (PDB), an activator of protein kinase C (PKC), induced slow-developing sustained contractions in segments of cat middle cerebral arteries. PDB-induced responses were not affected by phentolamine (1 microM) and endothelium removal, and were reduced by 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (25 microM) and staurosporine (10 nM), PKC inhibitors. Forskolin (25 microM) produced a rapid and marked vasodilation in segments contracted with PDB. The 4 alpha-phorbol 12,13-didecanoate, an inactive compound, induced slight vasodilation. Preincubation with nifedipine diminished the responses elicited by PDB at all concentrations used. Ca-free medium containing 3 mM ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA), but not 1 mM, markedly reduced the phorbol-induced responses at concentrations up to 10 nM. Nifedipine (0.1 microM) and forskolin (25 microM) produced a rapid and marked relaxation of PDB (10 nM)-evoked contractions in segments incubated in a Ca-free solution (1 mM EGTA), but PBD responses in 3 mM EGTA were not affected by nifedipine. PDB (10 and 100 nM) practically did not modify K-induced contractions, but reduced vasoconstrictions elicited by different norepinephrine concentrations; this effect was phorbol concentration and preincubation time-dependent. These results indicate that: 1) PDB induced PKC activation and contraction mainly produced by Ca entry (essentially at low PDB concentrations) through dihydropyridine-sensitive Ca channels; 2) the activated PKC has elevated sensitivity for Ca; 3) PKC may be involved in the alpha adrenoceptors desensitization, but did not play an important role in the norepinephrine-induced contraction in these arteries.
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PMID:Effects of phorbol 12,13-dibutyrate on the vascular tone and on norepinephrine- and potassium-induced contractions of cat cerebral arteries. 221 72

The treatment of human diploid fibroblasts with tumor necrosis factor (TNF)-alpha and with lymphotoxin (LT) is associated with induction of interleukin-6 (IL-6) transcripts with TNF-alpha being 10-fold more potent than LT. Here we report on the TNF-alpha/LT-induced signaling mechanisms responsible for the regulation of IL-6 gene expression in these cells. Run-on assays demonstrated that both TNF-alpha and LT increase IL-6 mRNA levels by transcriptional activation of this gene. Stability studies of IL-6 transcripts in fibroblasts showed that TNF-alpha delayed IL-6 mRNA decay but not LT. The induction of IL-6 transcripts by TNF-alpha and LT was not inhibited by the isoquinoline sulfonamide derivative H7. Similarly, depletion of protein kinase C (PKC) by 12-O-tetradecanoyl-phorbol 13-acetate (TPA) did not change the ability of TNF-alpha and LT to induce IL-6 transcripts, demonstrating that stimulation by these agents may not be mediated by activation of PKC. Stimulation of IL-6 transcripts in fibroblasts did also not require new protein synthesis as exposure to the protein synthesis inhibitor cycloheximide (CHX) enhanced accumulation of IL-6 mRNA in the presence or absence of TNF-alpha or LT.
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PMID:Differential regulation of interleukin-6 expression in human fibroblasts by tumor necrosis factor-alpha and lymphotoxin. 968 35

Tumor necrosis factor (TNF) elicits a wide variety of responses in target cells by binding to cell surface receptors, but the signal transduced from these receptors in unclear. We examined the role of two different second messenger systems in the regulation of plasminogen activator inhibitor, type 2 (PAI-2) induction by TNF in SK-MEL-109 melanoma cells. Synthesis of PAI-2 and transcription of its mRNA could be induced by a protein kinase C (PKC) activator, phorbol myristate acetate. In addition, induction of PAI-2 synthesis by TNF was blocked by two PKC inhibitors, staurosporine and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride. The inhibitor of cyclic nucleotide-dependent protein kinases, N-[2-(methylamino)-ethyl]-5-isoquinoline sulfonamide dihydrochloride, was much less effective in decreasing PAI-2 synthesis. Staurosporine and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride also inhibited both TNF- and phorbol myristate acetate-induced PAI-2 mRNA accumulation. We measured the binding of 3H-labeled phorbol dibutyrate to membrane and cytosol fractions of TNF-treated SK-MEL-109 cells and found a transient redistribution of 3H-labeled phorbol dibutyrate binding from cytosol to membrane fractions in response to TNF. In contrast to the positive regulation by PKC in promoting TNF-induced PAI-2 synthesis cAMP inhibited this response. Pretreatment of cells with agents that raise intracellular cAMP levels completely abolished TNF-induced PAI-2 synthesis. Addition of cAMP-elevating agents during TNF induction could also block PAI-2 synthesis. PAI-2 mRNA accumulation in response to TNF was inhibited, but not completely abolished, by cAMP-elevating agents, suggesting that cAMP also exerted its inhibitory effect at the translation level. The positive regulation of a TNF response by PKC and its negative modulation by cAMP may provide a means for intracellular coordination of signals from interacting extracellular factors in regulating TNF responses in different target cells.
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PMID:Positive and negative regulation of a tumor necrosis factor response in melanoma cells. 232 95

The roles of intracellular free Ca2+ and protein kinase C in the tonic contraction induced by prostaglandin were studied. Prostaglandin F2 alpha induced tonic contraction of rat thoracic aorta in both control and Ca2(+)-free solution. Close correlations were observed between the contractile response of aortic strips and the changes in intracellular free Ca2+ concentration in vascular smooth muscle cells assessed with the fluorescent Ca2+ indicator fura 2, both in control and Ca2(+)-free solutions. Prostaglandin F2 alpha also enhanced the production of inositol 1,4,5-trisphosphate in vascular smooth muscle cells before the rise of the intracellular free Ca2+ concentration. Moreover, 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine, an inhibitor of protein kinase C, inhibited the tonic contractions induced by PGF2 alpha and 12-O-tetradecanoyl phorbol-13-acetate, a direct activator of protein kinase C, at similar concentrations. These results suggest that both intracellular free Ca2+ and protein kinase C participate in prostaglandin F2 alpha-induced tonic contraction.
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PMID:Participation of both intracellular free Ca2+ and protein kinase C in tonic vasoconstriction induced by prostaglandin F2 alpha. 237 46

The KC gene is a cell cycle-dependent competence gene originally identified in platelet-derived growth factor-stimulated BALB/c-3T3 cells. This gene is also induced in murine peritoneal macrophages in response to activation stimuli. We have examined the expression of the KC gene in cultured porcine aortic endothelial cells following treatment with bacterial lipopolysaccharide (LPS) as a first step in defining the early molecular events involved in endothelial cell stimulation by physiologically relevant modulators. LPS markedly elevated the steady-state level of KC mRNA in confluent endothelial cells; maximum induction of KC occurred in the cells following exposure to 10 ng/ml LPS for 2 h. LPS did not increase the growth fraction of the cells, nor was the KC mRNA level changed in dense endothelial cells stimulated to enter the cell cycle with epidermal growth factor. However, KC mRNA expression was elevated by addition of serum to starved, subconfluent endothelial cell cultures. Treatment of endothelial cells with phorbol myristate acetate (PMA) and 1-oleoyl-2-acetyl-glycerol (OAG) also induced KC gene expression. A maximum response was obtained with 10 nM PMA, the effect decreasing with higher levels of the phorbol ester. The calcium ionophore A23187 exhibited little stimulatory activity alone; however, the ionophore did cause a doubling in the PMA-stimulated KC expression. The increased expression of KC induced by LPS and PMA was inhibited by the presence of 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine (H7), a protein kinase C inhibitor, but not by HA1004 (an H7 analogue with little protein kinase C inhibitory activity). No cytotoxicity was observed in inhibitor or LPS-treated endothelial cell cultures. These results demonstrate that KC gene expression is stimulated by LPS in vascular endothelial cells in a proliferation-independent process. Second, unlike LPS-induced KC expression in macrophages and platelet-derived growth factor-induced KC expression in 3T3 cells, LPS induction of KC in endothelial cells appears to require activation of protein kinase C.
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PMID:Lipopolysaccharide-induced expression of the competence gene KC in vascular endothelial cells is mediated through protein kinase C. 247 19

[3H]Arachidonic acid is released after stimulation of rabbit neutrophils with fMet-Leu-Phe or platelet-activating factor (PAF). The release is rapid and dose-dependent, and is inhibited in phorbol 12-myristate 13-acetate (PMA)-treated rabbit neutrophils. The protein kinase C (PKC) inhibitor 1-(5-isoquinoline-sulphonyl)-2-methylpiperazine (H-7) prevents this inhibition. In addition, PMA increases arachidonic acid release in H-7-treated cells stimulated with fMet-Leu-Phe. [3H]Arachidonic acid release, but not the rise in the concentration of intracellular Ca2+, is inhibited in pertussis-toxin-treated neutrophils stimulated with PAF. The diacylglycerol kinase inhibitor R59022 increases the concentration of diacylglycerol and potentiates [3H]arachidonic acid release in neutrophils stimulated with fMet-Leu-Phe. This potentiation is not inhibited by H-7. These results suggest several points. (1) A rise in the intracellular concentration of free Ca2+ is not sufficient for arachidonic acid release in rabbit neutrophils stimulated by physiological stimuli. (2) A functional pertussis-toxin-sensitive guanine nucleotide regulatory protein and/or one or more of the changes produced by phospholipase C activation are necessary for arachidonic acid release produced by physiological stimuli. (3) Agents that stimulate PKC potentiate arachidonic acid release, and this potentiation is not inhibited by H-7. These agents produce their actions in part by direct membrane perturbation.
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PMID:Arachidonic acid release in rabbit neutrophils. 277 41

We have studied the activation of the Na+/H+ exchanger which leads to the intracellular alkalinization in cultured bovine aortic endothelial cells stimulated by extracellular ATP. The alkalinization induced by ATP was largely dependent on extracellular Ca2+ and the rate of alkalinization was decreased by about 60% in the absence of extracellular Ca2+. ATP caused a rapid and transient increase and a subsequent sustained increase of the intracellular Ca2+ concentration ([Ca2+]i) in the Ca2+ buffer, while only the rapid and transient increase of [Ca2+]i was observed in the absence of extracellular Ca2+. The Ca2+-depleted cells prepared by incubation in Ca2+-free buffer containing 0.1 mM EGTA showed only a slight increase of [Ca2+]i with no alkalinization on stimulation by ATP. The alkalinization was inhibited by 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), an inhibitor of protein kinase C, but not by another isoquinoline analogue (HA 1004), which has a less inhibitory effect on the kinase. Phorbol 12-myristate 13-acetate also induced the alkalinization by the activation of the Na+/H+ exchanger. Neither dibutyryl cyclic AMP nor dibutyryl cyclic GMP affected the alkalinization induced by ATP. Treatment of the cells by pertussis and cholera toxins had no effect on the alkalinization. The results suggest that the increase in [Ca2+]i is essential for the ATP-induced activation of the Na+/H+ exchanger in cultured bovine aortic endothelial cells and a protein kinase C-dependent pathway is involved in the activation.
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PMID:Involvement of calcium and protein kinase C in the activation of the Na+/H+ exchanger in cultured bovine aortic endothelial cells stimulated by extracellular ATP. 254 11

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