Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Several tumor promoters exert their effects by activating a Ca2+-phospholipid-dependent protein kinase (protein kinase C). To study the role of this protein kinase in the regulation of Sertoli cell function, we have evaluated the effect of phorbol esters, mezerein, and teleocidin on the response of the Sertoli cell to FSH. Cells were treated for different time intervals with the tumor promoters, and cell response was measured by stimulating the cell with FSH. 12-O-Tetradecanoylphorbol 13-acetate (TPA) had no significant effect on basal cAMP production but markedly inhibited the cAMP response to FSH. Significant inhibition of cAMP accumulation was observed after 15 min treatment with 100 nM TPA, and maximal inhibition developed within 1 h. The decrease in cAMP accumulation was dependent on the dose of phorbol ester used, with an estimated ED50 of 10-20 nM TPA. In a manner similar to TPA, mezerein and teleocidin also inhibited the cAMP response of the Sertoli cell, while the phorbol ester 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD), inactive as a tumor promoter and unable to stimulate protein kinase C activity, was devoid of effect. The promoters that inhibited cAMP response also inhibited the FSH-stimulated androgen aromatization. The dose of TPA producing half-maximal inhibition of estrogen accumulation was again 10-20 nM TPA, mezerein, and teleocidin inhibited estrogen accumulation whether FSH, forskolin or cholera toxin was used to stimulate the Sertoli cell. In contrast, only FSH-dependent cAMP accumulation was inhibited by the tumor promoters, while forskolin and cholera toxin stimulations were not affected. These data suggest that tumor promoters which activate protein kinase C act at two sites of the Sertoli cell response. They alter receptor-mediated signal transduction across the membrane and affect steroidogenesis at a site distal to cAMP accumulation.
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PMID:Inhibition by phorbol esters and other tumor promoters of the response of the Sertoli cell to FSH: evidence for dual site of action. 303 Aug 55

In 3T3-F442A cells, TGF-beta caused cellular proliferation in a time and dose-dependent manner. TGF-beta induced cyclin D1 and cdk2 proteins in 3T3-F442A cells. The mitogenic effect of TGF-beta was specific in nature. The antimitogenic agent, hGH, inhibited the mitogenic effect of TGF-beta and was associated with inhibition of cyclin D1 expression. The protein kinase c inhibitor, staurosporine, inhibited the mitogenic effect of TGF-beta. Taken together, these results suggest that TGF-beta affects expression levels of cell cycle-regulated proteins and its mitogenic effect is mediated through protein kinase C in 3T3-F442A cells.
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PMID:Mitogenic response to TGF-beta in 3T3-F442A cells. 748 18

The transforming growth factor beta s (TGF-beta s) are a group of multifunctional growth factors that inhibit cell cycle progression in many cell types. The TGF-beta-induced cell cycle arrest has been partially attributed to the regulatory effects of TGF-beta on both the levels and activities of the G1 cyclins and their cyclin-dependent kinase partners. The ability of TGF-beta to inhibit the activity of these kinase complexes derives in part from its regulatory effects on the cyclin-dependent kinase inhibitors, p21/WAF1/Cip1, p27Kip1, and p15. Upon treatment of cells with TGF-beta, these three inhibitors bind to and block the activities of specific cyclin-cyclin-dependent kinase complexes to cause cell cycle arrest. Little is known, however, on the mechanism through which TGF-beta activates these cyclin-dependent kinase inhibitors. In the case of p21, TGF-beta treatment leads to an increase in p21 mRNA. This increase in p21 mRNA is partly due to transcriptional activation of the p21 promoter by TGF-beta. To further define the signaling pathways through which TGF-beta induces p21, we have performed a detailed functional analysis on the p21 promoter. Through both deletion and mutation analysis of the p21 promoter, we have defined a 10-base pair sequence that is required for the activation of the p21 promoter by TGF-beta. In addition, this sequence is sufficient to drive TGF-beta-mediated transcription from a previously nonresponsive promoter. Preliminary gel shift assays demonstrate that this TGF-beta responsive element binds specifically to several proteins in vitro. Two of these proteins are the transcription factors Sp-1 and Sp-3. These studies represent the initial steps toward defining the signaling pathways involved in TGF-beta-mediated transcriptional activation of p21.
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PMID:Functional analysis of the transforming growth factor beta responsive elements in the WAF1/Cip1/p21 promoter. 749 79

Cyclin-dependent kinases (cdks) are a family of proteins whose function plays a critical role in cell cycle traverse. Transforming growth factor-beta 1 (TGF-beta 1) is a potent growth inhibitor of epithelial cells. Since cdks have been suggested as possible biochemical markers for TGF-beta growth inhibition, we investigated the effect of TGF-beta 1 on cdc2 and cdk2 in a normal mouse mammary epithelial cell line (MME) and a TGF-beta-resistant MME cell line (BG18.2). TGF-beta 1 decreases newly synthesized cdc2 protein levels within 6 h after addition. Coincident with this decrease in newly synthesized cdc2 protein was a marked reduction in its ability to phosphorylate histone H1. This decrease in kinase activity is not due to a change in steady-state levels of cdc2 protein, since mRNA and total protein levels of cdc2 are not reduced until 12 h after TGF-beta 1 addition. This suggests that the kinase activity of cdc2 is dependent on newly synthesized cdc2 protein. Moreover, the protein synthesis of another cyclin-dependent kinase, cdk2, is not effected by TGF-beta 1 addition, but its kinase activity is substantially reduced. Thus, it appears that TGF-beta decreases the kinase activity of both cdc2 and cdk2 by distinct mechanisms.
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PMID:Differential regulation of p34cdc2 and p33cdk2 by transforming growth factor-beta 1 in murine mammary epithelial cells. 759 74

In this work, we demonstrate the signal-transducing mechanism of TGF-beta 1 for gene expression of monocyte chemoattractant JE/monocyte chemoattractant protein 1 (MCP-1) in clonal osteoblastic MC3T3-E1 cells. TGF-beta 1-induced JE/MCP-1 gene expression in the cells was inhibited markedly by H-7 (1-(5-isoguinolinesulfonyl)-2-O-methylpiperazine-dihydrochloride) and staurosporine, potent inhibitors of protein kinase. TGF-beta 1-induced expression of both early proto-oncogenes c-fos and c-jun in the cells was also inhibited by H-7 and staurosporine. Antisense oligonucleotides to c-fos and c-jun genes inhibited significantly the cytokine-induced JE/MCP-1 gene expression. Curcumin, a specific inhibitor of c-jun/AP-1, inhibited the cytokine-induced c-jun gene expression in a dose-dependent manner, though the c-fos gene expression was not affected. TGF-beta 1 stimulated transcriptionally the JE/MCP-1 gene expression, and this stimulation was inhibited significantly by curcumin. Curcumin-induced inhibition of the JE/MCP-1 gene product was also evidenced by both an assay involving immunoprecipitation with antiserum specific for JE/MCP-1 and an assay for monocyte chemotaxis. Curcumin markedly inhibited AP-1 binding activity to 12-tetradecanoyl phorbol-13-acetate-responsive element (TRE) in the cytokine-treated cells. Furthermore, H-7 and staurosporine also inhibited the binding activity to TRE in the cells treated by the cytokine. These results demonstrate that TGF-beta 1 induces expression of monocyte chemoattractant JE/MCP-1 via the transcriptional factor AP-1 induced by protein kinase in the osteoblastic cells.
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PMID:TGF-beta induces expression of monocyte chemoattractant JE/monocyte chemoattractant protein 1 via transcriptional factor AP-1 induced by protein kinase in osteoblastic cells. 760 15

MBA-2, bone marrow-derived endothelial stromal cells, express platelet-derived growth factor (PDGF) A and B chain mRNAs and secrete PDGF activity that is induced by TGF-beta. Either chain of the PDGF molecule could modulate hematopoiesis and stromal cell growth. Intracellular pathways that regulate PDGF expression in the marrow microenvironment are unknown. In the present study, we examined the mechanisms that mediate PDGF A and B chain mRNA induction by TGF-beta and the role of protein kinase C (PKC) and cyclic AMP in PDGF regulation. TGF-beta was tested in parallel with PMA, an activator of phorbol ester-dependent PKC isoforms. Both PMA (10(-7)M) and TGF-beta (2.5 ng/ml) increased PDGF A and B chain mRNA levels. The serine/threonine protein kinase inhibitor, H7, blocked PDGF A and B chain mRNA induction in response to TGF-beta. However, down-regulation of PKC by prolonged incubation with PMA failed to abolish TGF-beta induction of PDGF A and B chain mRNAs. These findings indicate that induction of PDGF A and B chain mRNAs can be mediated via phorbol ester-dependent PKC pathway. In contrast, H7-sensitive protein kinase(s) other than phorbol ester-sensitive protein kinase C mediate the effect of TGF-beta. Agents that increase cAMP were also tested for their effect on PDGF gene expression. TGF-beta-mediated induction of PDGF A and B chain mRNAs was markedly inhibited by cAMP. cAMP also blocked stimulation of PDGF A chain mRNA by PMA. The positive and negative signaling mechanisms involved in modulating PDGF in the microenvironment may be important for determining hematopoietic and stromal cell responses in vivo.
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PMID:Regulation of platelet-derived growth factor A and B chain gene expression in bone marrow stromal cells. 762 89

Addition of 100 nM phorbol 12-myristate 13-acetate (PMA), an active phorbol diester, to quiescent cultured Madin-Darby canine kidney (MDCK) cells caused a maximal stimulation of phosphatidylethanol formation within 1-2 h in the presence of 1% ethanol, indicating the activation of phospholipase D (PLD). The specificity of phorbol diesters for the activation of PLD activation was confirmed by the fact that phorbol 12,13-dibutyrate (PDBu) was effective, whereas 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD) was without effect. Down-regulation caused by the long-term pretreatment of the cells with active phorbol diesters significantly decreased the production of phosphatidylethanol. Staurosporine, a well known protein kinase (PK)C inhibitor at 1 microM, decreased the activation of PLD. Taken together, these observations suggested the involvement of PKC in the activation of PLD. The cellular PLD activity was found to be selectively localized in the particulate fraction by centrifugation at 12,000 x g. The particulate PLD showed the selective substrate specificity for phosphatidylcholine rather than phosphatidylethanolamine. In response to the addition of 100 nM PMA, 1,2-diacylglycerol (DG) increased in a biphasic fashion. In view of the time course of the activation of PLD, the second increase in the 1,2-DG around 20 min was contributed by the activation of PLD. In response to the simultaneous addition of 100 nM PMA and 100 nM A23187, the cultured MDCK cells activated the arachidonate cascades to form prostaglandin (PG)E2 and PGF2 alpha as major products, requiring slower 24 h to reach maximal levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Activation mechanism of phospholipase D involved in the generation of lipid mediators in cultured Madin-Darby canine kidney cells. 767 Jan 90

Growth of thyroid cancer cells is stimulated by various growth factors via signal transduction pathways. TSH, EGF, IGF, and TGF-alpha stimulate and TGF-beta inhibits thyroid cell growth. TSH stimulates thyroid cells via both the adenylate cyclase-PKA and the PLC-PKC-Ca signal transduction pathways. TSH-r, ras, gsp, ret, trk, and myc are oncogenes that are activated in some thyroid neoplasms. P53 and RB are tumor suppressor genes that are inactivated in some thyroid cancers.
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PMID:Thyroid growth factors, signal transduction pathways, and oncogenes. 774 50

It has recently become clear that cyclin-dependent kinase (cdk) complex regulates the cell cycle by phosphorylating Rb protein, a tumor suppressor protein. It is likely that this complex is a target of various growth factors and anti-growth factors (UV, TGF-beta etc.) in keratinocyte (KC). It has also been suggested that abnormalities in the cell cycle regulating mechanism such as increased activity of cyclin-cdk due to mutation of p53, a tumor suppressor gene, and overexpression of cyclin D may be concerned with carcinogenesis of KC. Thus, recent studies indicate that the cyclin-cdk complex is a common target of proliferation and carcinogenesis in KC.
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PMID:Cell cycle regulators in the keratinocyte (cyclin-cdk). 775 27

It is known that mechanical stress directly changes the conformation of the functional proteins, or directly activates enzymes such as phospholipase in the plasma membrane. The integrin-cytoskeleton complex may be an alternative candidate structure for a mechanoreceptor and a transducer. The cytoskeleton has been also shown to play an important role in secretion. Mechanical stress may stimulate the secretion of some cytokines or angiotensin II, which may generate multiple intracellular signals as a secondary event. External stimuli are generally transduced into the nucleus through the activation of protein kinase cascade. Stretching of cardiac myocytes stimulates the activity of PKC, Raf-1 kinase, MAP kinase kinase. MAP kinase and S6 kinase. In cardiac myocytes, mechanical stress directly induces gene expression as well as protein synthesis. Immediate early genes are first induced, and then fetal-type genes are reinduced. Both in hypertrophied hearts and in the experimental model of cardiac hypertrophy induced by pressure overload. Ca(2+)-ATPase content of cardiac myocytes is depressed. Reduced function of sarcoplasmic reticulum causes insufficient decrease of intracellular calcium in diastole and induces slowing of ventricular relaxation. In the interstitium of pressure overloaded hearts, the accumulation of collagen fiber is increased. The abnormal deposit leads to increased chamber stiffness and diastolic dysfunction. Furthermore, TGF-beta and tissue renin-angiotensin system are up-regulated in pressure overloaded hearts, both of which accelerate the interstitial fibrosis.
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PMID:Interaction of cardiac myocytes and non-myocytes in mechanical stress-induced hypertrophy. 777 62


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