K04166 AGTR1; angiotensin II receptor type 1 K04634 GNAQ; guanine nucleotide-binding protein G(q) subunit alpha K04635 GNA11; guanine nucleotide-binding protein subunit alpha-11 K05858 PLCB; phosphatidylinositol phospholipase C, beta [EC:3.1.4.11] K05858 PLCB; phosphatidylinositol phospholipase C, beta [EC:3.1.4.11] K05858 PLCB; phosphatidylinositol phospholipase C, beta [EC:3.1.4.11] K05858 PLCB; phosphatidylinositol phospholipase C, beta [EC:3.1.4.11] K04958 ITPR1; inositol 1,4,5-triphosphate receptor type 1 K04959 ITPR2; inositol 1,4,5-triphosphate receptor type 2 K04960 ITPR3; inositol 1,4,5-triphosphate receptor type 3 K02677 PRKCA; classical protein kinase C alpha type [EC:2.7.11.13] K19662 PRKCB; classical protein kinase C beta type [EC:2.7.11.13] K19663 PRKCG; classical protein kinase C gamma type [EC:2.7.11.13] K18050 PRKCE; novel protein kinase C epsilon type [EC:2.7.11.13] K06070 PKD; protein kinase D [EC:2.7.11.13] K06070 PKD; protein kinase D [EC:2.7.11.13] K06070 PKD; protein ...
Complement factor C3, recently found to contain covalently bound phosphate, was phosphorylated in vitro by cyclic AMP-dependent protein kinase (protein kinase A) and Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C). Both protein kinases phosphorylated the same serine residue(s) located in the C3a portion of the alpha-chain. In addition, protein kinase C phosphorylated the beta-chain to a lesser extent. Protein kinase A gave a maximal incorporation of 1 mol of phosphate/mol of C3 while that value with protein kinase C was 1.5 mol of phosphate/mol of C3. The velocity in pmol of [32P]phosphate/(min x unit kinase) was 20 times higher for protein kinase C than for protein kinase A although a 10 times lower ratio of protein kinase to C3 was used in the former case. The apparent Kmfor C3 was 2.6 µM when protein kinase C was used. The phosphorylated C3 was found to be more resistant to partial degradation by trypsin than unphosphorylated C3. It was also found that ...
TY - JOUR. T1 - Identification of a nuclear protein binding element within the rat brain protein kinase C γ promoter that is related to the developmental control of this gene. AU - Chen, Kuang Hua. AU - Widen, Steven. AU - Wilson, Samuel H.. AU - Huang, Kuo Ping. PY - 1993/7/5. Y1 - 1993/7/5. N2 - Protein kinase C γ (PKC γ) is a brain-specific isozyme expressed at a high level in the adult but not in the fetal or newborn rat. At least seventeen nuclear protein binding sites within the 5-flanking region extending from -1612 to +243 had been identified by DNase I footprinting analysis and gel mobility shift assays. Among them, one site, GAATTAATAGG, at -669 to -679 is protected from DNase I digestion by nuclear protein from newborn but not from the adult rat brain. The levels of this binding protein, as determined by gel mobility shift assay, were found inversely related to the levels of PKC γ in rat brain at different stages of development. These results suggest that this particular binding ...
TY - JOUR. T1 - A role for protein kinase C-mediated phosphorylation in eliciting glucagon desensitization in rat hepatocytes. AU - Savage, A.. AU - Zeng, L.. AU - Houslay, M. D.. PY - 1995/4/1. Y1 - 1995/4/1. N2 - An immobilized hepatocyte preparation was used to show that both vasopressin and glucagon could desensitize the ability of glucagon to increase intracellular cyclic AMP concentrations. This process was not dependent on any influx of extracellular Ca2+ and was not mediated by any rise in the intracellular level of Ca2+. The protein kinase C-selective inhibitors chelerythrine, staurosporine and calphostin C acted as potent inhibitors of the desensitization process but with various degrees of selectivity regarding their ability to inhibit the desensitizing actions of glucagon and vasopressin. The protein phosphatase inhibitor okadaic acid was just as potent as vasopressin and glucagon in causing desensitization. Treatment of hepatocyte membranes with alkaline phosphatase restored to near ...
We previously established a cell line from a patient with acute myelomonocytic leukemia with eosinophilia (M4E0), ME-1. ME-1 cells are responsive to colony-stimulating factors (CSFs) such as interleukin-3 (IL-3), IL-4, and granulocyte-macrophage CSF (GM-CSF), and exhibit monocyte-macrophage differentiation. We isolated three subclones, ME-F1 from ME-1, and ME-F2 and ME-F3 from two sublines of ME-1. These subclones had different morphologic, cytochemical, phenotypic, and cytogenetic features. They represented different monocytic-lineage differentiation stages and exhibited different responses to IL-3, GM- CSF, and especially IL-4. IL-3, GM-CSF, and IL-4 enhanced proliferation and differentiation to macrophage-like cells in the ME-F1 subclone. However, they enhanced only proliferation of ME-F2 cells and only differentiation to macrophage-like cells in the ME-F3 subclone. To elucidate possible differences in signal transduction mechanisms in ME- F1, ME-F2, and ME-F3 cells following stimulation by ...
TY - JOUR. T1 - Modulation of chemosensitivity in human colon carcinoma cells by downregulating Protein Kinase Cα expression. AU - Chakrabarty, Subhas. AU - Huang, Shuang. PY - 1996/7/1. Y1 - 1996/7/1. N2 - Protein kinase C (PKC) is thought to play a role in tumor progression and drug resistance of colon carcinomas. Specifically, the PKCα isoform has been implicated in drug resistance and responsiveness of colon carcinoma cells to growth factors. Therefore, in this study we determined the effect of downregulating PKCα expression by transfecting human colon carcinoma cells with an antisense PKCα expression vector and then determined the sensitivity of these cells to the anticancer drugs mitomycin C (MMC), 5-fluorouracil (5-FU) and vincristine (Vin). Transiently transfecting the human colon carcinoma cell lines Moser, SW480 and HT29 with antisense PKCα expression vector (but not antisense PKCβ expression vector) consistently increased the sensitivity of these cells to MMC, 5-FU and VIN by ...
TY - JOUR. T1 - Differential effects of protein kinase C inhibitors on chemokine production in human synovial fibroblasts. AU - Jordan, Nicola J.. AU - Watson, Malcolm L.. AU - Yoshimura, Teizo. AU - Westwick, John. PY - 1996. Y1 - 1996. N2 - 1. Rheumatoid arthritis is associated with the accumulation and activation of selected populations of inflammatory cells within the arthritic joint. One putative signal for this process is the production, by resident cells, of a group of inflammatory mediators known as the chemokines. 2. The chemokines interleukin-8 (IL-8), monocyte chemotactic protein-1 (MCP-1) and RANTES (regulated on activation normal T-cell expressed and presumably secreted) are target-cell specific chemoattractants produced by synovial fibroblasts in response to stimulation with interleukin-1α (IL-1α) or tumour necrosis factor α (TNFα). The signalling pathways involved in their production are not well defined. We therefore used four different protein kinase C inhibitors to ...
TY - JOUR. T1 - Protein kinase C regulates the tonic but not the phasic component of contraction in guinea-pig ileum. AU - Sasaguri, T.. AU - Watson, S. P.. PY - 1989/1/1. Y1 - 1989/1/1. N2 - We have investigated the effect of phorbol esters and the down-regulation of protein kinase C on contraction of guinea-pig ileum longitudinal smooth muscle to carbachol and high K+. Phorbol 12,13-dibutyrate (PDBu) enhanced the phasic component and inhibited or enhanced, respectively, the tonic component of contraction to carbachol and high K+. In contrast, 4α-phorbol, which does not activate protein kinase C, had no effect on these responses. Exposure to phorbol 12-myristate 13-acetate (PMA; 1 μM) for up to 8 h induced a time-dependent loss of [3H]-PDBu binding sites, consistent with the down-regulation of protein kinase C by this treatment. The phasic component of contraction to carbachol or high K+ was unaffected following the down-regulation of protein kinase C. The tonic component of contraction to ...
Protein kinase C regulates the activity of a diverse group of cellular proteins including membrane ion channel proteins. Although protein kinase C and its substrate protein have been identified in both membrane and cytosolic fractions in the heart, the physiological role of this kinase in the regulation of cardiac function remains unknown. We examined the physiological role of protein kinase C by stimulating its activity with 12-deoxyphorbol 13 isobutyrate 20 acetate (DPBA) in human trabeculae carneae. This resulted in decreased peak isometric twitch force and peak intracellular sarcoplasmic reticulum calcium release as detected with aequorin. Furthermore, in the presence of DPBA, steady-state force-[Ca2+] relations were shifted to higher intracellular calcium concentrations, and the Hill coefficient was reduced, indicating a decrease in responsiveness of the myofilaments to calcium and a change in cooperativity among thin filament proteins, respectively. Thus, DPBA affects not only ...
Effects of pentoxifylline and protein kinase C inhibitor on phorbol ester-induced intercellular adhesion molecule-1 expression in brain microvascular endothelial cells.
TY - JOUR. T1 - Inhibition of the spontaneous rate of contraction of neonatal cardiac myocytes by protein kinase C isozymes. T2 - A putative role for the ε isozyme. AU - Johnson, John A. AU - Mochly-Rosen, Daria. PY - 1995/1/1. Y1 - 1995/1/1. N2 - Protein kinase C (PKC) enzymes regulate numerous cardiac functions. In the present study, we determined the effects of the PKC-activating drug 4-β phorbol 12-myristate 13-acetate (4-β PMA) on the rate of contraction and correlated these changes with the distribution and levels of α-, β-, δ-, ε-, and ζ-PKC isozymes by using neonatal rat cardiac myocytes in culture. Treatment with 0.3 to 100 nmol/L 4-β PMA caused negative chronotropic effects on contraction. This effect was maximal at a concentration of 3 nmol/L 4-β PMA and correlated with redistribution of the α- and ε-PKC isozymes from the cytosolic to the particulate cell fraction. After a 1-hour treatment with 100 nmol/L PMA, the α- and β-PKC isozymes and an 80-kD ζ- like PKC isozyme ...
TY - JOUR. T1 - Isolation and characterization of two new Drosophila protein kinase C genes, including one specifically expressed in photoreceptor cells. AU - Schaeffer, Eric. AU - Smith, Dean. AU - Mardon, Graeme. AU - Quinn, William. AU - Zuker, Charles. PY - 1989/5/5. Y1 - 1989/5/5. N2 - We have isolated and characterized two new protein kinase C (PKC) genes from D. melanogaster. One, dPKC98F, maps to chromosome region 98F and displays over 60% amino acid sequence identity with members of a recently described "PKC-related" subfamily in mammals. The other, dPKC53E(ey), maps to region 53E 4-7 on the second chromosome and lies within 50 kb of a PKC gene previously characterized (dPKC). While dPKC98F transcripts are expressed throughout development, expression of the two genes mapping at cytogenetic location 53E is primarily in adults. dPKC98F and the previously reported 53E gene are transcribed predominantly in brain tissue. In contrast, dPKC53E(ey) is transcribed only in photoreceptor cells. We ...
We found that removal of Ca2+ and inhibition of PKC prevented high Pi-induced O2·− production (Figures 3A and 3B), indicating a role for mechanosensitive Ca2+ signaling and PKC-dependent pathways in high Pi-induced upregulation of NAD(P)H oxidase activity. This idea is consistent with the findings that high Pi elicited significantly greater increases in smooth muscle [Ca2+]i than normal levels of Pi (Figure 4). The important role of Ca2+ signaling is also supported by the finding that administration of a Ca2+ ionophore resulted in significantly increased arterial O2·− production (Figure 3C). Further, pharmacological activation of PKC2 elicited substantial increases in arterial NAD(P)H oxidase-derived O2·− generation (Figure 3C). Because removal of Ca2+ during high-pressure treatment prevented endothelial dysfunction (Figure 1) and increases in O2·− production in high Pi-exposed arteries (Figure 3A) and phorbol ester-stimulated O2·− generation in normotensive arteries could also be ...
This investigation deals with the molecular mechanism of anti-human immunodeficiency virus type 1 (HIV-1) action of pentoxifylline (PTX) [1-(5′-oxohexyl)-3,7-dimethylxanthine] a drug widely used for the treatment of conditions involving defective regional microcirculation. The inhibition by PTX of protein kinase C (PKC) or cAMP-dependent protein kinase (PKA)-mediated activation by phorbol ester (PMA) and tumor necrosis factor alpha (TNF-α) of HIV-1-LTR-regulated reporter gene expression was studied in human CD4+ T lymphocytes (Jurkat) and human embryo kidney cells (293-27-2). A protein kinase C is involved in activation of NF-κB in whole cells, identified by using inhibitors specific for PKC- or PKA-catalyzed NF-κB activation in whole cell and cell-free systems. PTX inhibited PKC- or PKA-catalyzed activation of NF-κB in cytoplasmic extracts from unstimulated Jurkat or 293-27-2 cells, but not interaction of preactivated NF-κB with its motifs. Calphostin C, a specific inhibitor of PKC, inhibited NF
TY - JOUR. T1 - Photoactivated inhibition of superoxide generation and protein kinase C activity in neutrophils by blepharismin, a protozoan photodynamically active pigment. AU - Watanabe, Yoshiya. AU - E-ige, Keisuke. AU - Kobuchi, Hirotsugu. AU - Kato, Yoji. AU - Matsuoka, Tatsuomi. AU - Utsumi, Toshihiko. AU - Yoshioka, Tamotsu. AU - Horton, Alan A.. AU - Utsumi, Kozo. PY - 1995/2/14. Y1 - 1995/2/14. N2 - Blepharismin is an endogenous photosensitizing pigment found in the protozoan Blepharisma. This pigment inhibited the generation of Superoxide anion (O2-) in neutrophils not only via a diacylglycerol-induced protein kinase C (PKC)-dependent reaction but also by an arachidonate-induced PKC-independent reaction. The inhibition was light and concentration dependent for both reactions. Light-activated inhibition was strong at wavelengths between 520 and 570nm but not above 610nm. PKC activity in neutrophils and from rat brain was inhibited by blepharismin in a light- and concentration dependent ...
TY - JOUR. T1 - Differential effects of protein kinase C on the levels of epithelial Na+ channel subunit proteins. AU - Stockand, James D. AU - Hui-Fang, B.. AU - Schenck, J.. AU - Malik, B.. AU - Middleton, P.. AU - Schlanger, L. E.. AU - Eaton, D. C.. PY - 2000/8/18. Y1 - 2000/8/18. N2 - Regulation of epithelial Na+ channel (ENaC) subunit levels by protein kinase C (PKC) was investigated in A6 cells. PKC activation altered ENaC subunit levels, differentially decreasing the levels of both β and γ, but not αENaC. Temporal regulation of β and γENaC by PKC differed; γENaC decreased with a time constant of3.7 ± 1.0 h, whereas βENaC decreased in 13.9 ±3.0h. Activation of PKC also resulted in a decrease in trans-epithelial Na+ reabsorption for up to 48h. PMA activation of PKC resulted in negative feedback inhibition of PKC protein levels beginning within 4h. Both β and γENaC levels, as well as transport tended toward pretreatment values after 48 h of PMA treatment. PKC inhibitors ...
TY - JOUR. T1 - Synthesis and protein kinase C binding activity of benzolactam-V7. AU - Ma, Dawei. AU - Wang, Guoqiang. AU - Wang, Shaomeng. AU - Kozikowski, Alan P.. AU - Lewin, Nancy E.. AU - Blumberg, Peter M.. PY - 1999/5/17. Y1 - 1999/5/17. N2 - Benzolactam-V7 (3a), a simplified analogues of (-)-indolactam-V with twist-form conformation, was synthesized and evaluated as a new protein kinase C modulator. Both 3a and its-7-substituted analogue 3c showed weak binding activity to displace PDBU binding from recombinant PKCα.. AB - Benzolactam-V7 (3a), a simplified analogues of (-)-indolactam-V with twist-form conformation, was synthesized and evaluated as a new protein kinase C modulator. Both 3a and its-7-substituted analogue 3c showed weak binding activity to displace PDBU binding from recombinant PKCα.. UR - http://www.scopus.com/inward/record.url?scp=0033577690&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0033577690&partnerID=8YFLogxK. U2 - ...
TY - JOUR. T1 - Role of Ras in signal transduction from the nerve growth factor receptor. T2 - Relationship to protein kinase C, calcium and cyclic AMP. AU - Szeberenyi, J.. AU - Erhardt, P.. AU - Cai, H.. AU - Cooper, G. M.. PY - 1992/1/1. Y1 - 1992/1/1. N2 - A dominant inhibitory ras mutant (Ha-ras Asn-17) has been used to investigate the role of Ras in nerve growth factor (NGF)-mediated signal transduction in PC12 cells. Expression of Ha-Ras Asn-17 blocks neuronal differentiation of these cells in response to NGF treatment. The Ha-Ras Asn-17 block was bypassed by treatment with NGF plus dibutyryl cAMP or NGF plus the Ca2+ ionophore ionomycin, but not by NGF plus 12-O-tetradecanoyl phorbol acetate (TPA). Direct stimulation of the cAMP or Ca2+ pathways thus appeared to act synergistically with a Ras-independent NGF signaling pathway. This Ras-independent pathway was also distinct from protein kinase C, since its activity was not affected by protein kinase C down-regulation. It thus appears that ...
Protein Kinase C Theta Type (nPKC Theta or PRKCQ or EC 2.7.11.13) - Pipeline Review, H1 2017 Size and Share Published in 2017-05-30 Available for US$ 3500 at Researchmoz.us
Correlation between endogenous membrane PKC activity and proliferation versus differentiation of normal and HPV16 transformed rat myoblast (L 6 cells): Histochem.J.
Catalytic domain of the Protein Serine/Threonine Kinase, Classical Protein Kinase C. Serine/Threonine Kinases (STKs), Classical (or Conventional) Protein Kinase C (cPKC) subfamily, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The cPKC subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase (PI3K). PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. PKCs undergo three phosphorylations in order to take mature forms. In addition, cPKCs depend on calcium, DAG (1,2-diacylglycerol), and in most cases, phosphatidylserine (PS) for activation. cPKCs contain a calcium-binding C2 region in their regulatory domain. There are four cPKC ...
The activity of calcium-, phospholipid-dependent protein kinase (PKc) was measured in (a) total extracts, (b) crude membrane, and (c) cytosolic fractions of chick embryo myogenic cells differentiating in culture. Total PKc activity slowly declines during the course of terminal myogenesis in contrast to the activity of cAMP-dependent protein kinase, which was also measured in the same cells. Myogenic cells at day 1 of culture possess high particulate and low soluble PKc activity. A dramatic decline of particulate PKc activity occurs during myogenic cell differentiation and is accompanied, through day 4, by a striking rise of the soluble activity. The difference in the subcellular distribution of PKc between replicating myoblasts and myotubes is confirmed by phosphorylation studies conducted in intact cells. These studies demonstrate that four polypeptides whose phosphorylation is stimulated by the tumor promoter 12-O-tetradecanoyl phorbol 13-acetate in myotubes, are spontaneously phosphorylated ...
Octadecadienoic acids (linoleic acid and linolelaidic acid) and the diacylglycerol, 1-oleoyl-2-acetyl-rac-glycerol (OAG) concentration-dependently induced activation of gel-filtered human platelets, i.e. aggregation and phosphorylation of 20 kDa and 47 kDa peptides. In contrast, octadecenoic acids (oleic and elaidic acid) and octadecanoic (stearic) acid were inactive. Octadecadienoic acid-induced platelet activation was suppressed by the protein kinase C inhibitor, polymyxin B, but not by the cyclooxygenase inhibitor, indomethacin. OAG-induced activation was potentiated by octadecadienoic acids present at non-stimulatory concentrations. Our data suggest that octadecadienoic acids and diacylglycerol synergistically induce platelet activation via protein kinase C. Furthermore, linolelaidic acid may provide a useful experimental tool to study fatty acid regulation of protein kinase C in intact cells. ...
TY - JOUR. T1 - "Functional mapping of the promoter region of the GNB2L1 human gene coding for RACK1 scaffold protein". AU - Del Vecchio, Igor. AU - Zuccotti, Annalisa. AU - Pisano, Federica. AU - Canneva, Fabio. AU - Lenzken, Silvia C.. AU - Rousset, Francoise. AU - Corsini, Emanuela. AU - Govoni, Stefano. AU - Racchi, Marco. PY - 2009/2/1. Y1 - 2009/2/1. N2 - RACK1 (Receptor for Activated C Kinase 1) is a scaffold protein for different kinases and membrane receptors. Previously, we characterized an age-dependent decline of RACK1 protein expression which could be counteracted with DHEA (dehydroepiandrosterone) [Corsini, E., et al. 2002. In vivo dehydroepiandrosterone restores age-associated defects in the protein kinase C signal transduction pathway and related functional responses. J. Immunol. 168, 1753-1758. and Corsini, E., et al. 2005. Age-related decline in RACK-1 expression in human leukocytes is correlated to plasma levels of dehydroepiandrosterone. J. Leukoc. Biol. 77, 247-256.]. ...
Translocation of PKC isoforms has been implicated in mechanisms involved in heart failure, 22myocardial hypertrophy, 23and preconditioning. PKC isoforms are activated by phosphorylating enzymes such as G proteins and are modified in enzyme activity by phospholipids, diacylglycerol, increased Ca2+, nitric oxide, and superoxide anions. This is followed by translocation in an isoform-specific and cytoskeleton-mediated manner to subcellular targets, which can be directly visualized by immunohistochemical methods. Only 10 min of ischemia 24or brief administrations of pharmacologic agents 11,25may elicit significant PKC translocation. Recent evidence indicates that translocation is dependent on PKC binding to a family of proteins called receptors of activated C kinase. 26These anchoring proteins are highly specific, and each PKC isoenzyme can bind to only one receptor of activated C kinase. Thus, different PKC isoforms may be linked to distinctive aspects of myocardial function, and this functional ...
The N-methyl-D-aspartate receptor (NMDAR) is an ionotropic glutamate receptor, which plays crucial roles in synaptic plasticity and development. We have recently shown that potentiation of NMDA receptor function by protein kinase C (PKC) appears to be mediated via activation of non-receptor tyrosine kinases. The aim of this study was to test whether this effect could be mediated by direct tyrosine phosphorylation of the NR2A or NR2B subunits of the receptor. Following treatment of rat hippocampal CA1 mini-slices with 500 nM phorbol 12-myristate 13-acetate (PMA) for 15 min, samples were homogenized, immunoprecipitated with anti-NR2A or NR2B antibodies and the resulting pellets subjected to Western blotting with antiphosphotyrosine antibody. An increase in tyrosine phosphorylation of both NR2A (76 +/- 11% above control) and NR2B (41 +/- 11%) was observed. This increase was blocked by pretreatment with the selective PKC inhibitor chelerythrine, with the tyrosine kinase inhibitor Lavendustin A or with the
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TY - JOUR. T1 - Chromatinized Protein Kinase C-theta: Can It Escape the Clutches of NF-kB?. AU - Sutcliffe, Elissa. AU - Li, Jasmine. AU - Zafar, Anjum. AU - Hardy, Kristine. AU - Ghildyal, Reena. AU - Norris, Nicole. AU - Lim, Chloe (Pek Siew). AU - Milburn, Peter. AU - Casarotto, Marco. AU - Denyer, Gareth. AU - Rao, Sudha. PY - 2012. Y1 - 2012. N2 - We recently provided the first description of a nuclear mechanism used by Protein Kinase C-theta (PKC-θ) to mediate T cell gene expression. In this mode, PKC-θ tethers to chromatin to form an active nuclear complex by interacting with proteins including RNA polymerase II, the histone kinase MSK-1, the demethylase LSD1, and the adaptor molecule 14-3-3ζ at regulatory regions of inducible immune response genes. Moreover, our genome-wide analysis identified many novel PKC-θ target genes and microRNAs implicated in T cell development, differentiation, apoptosis, and proliferation. We have expanded our ChIP-on-chip analysis and have now identified a ...
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We have provided clear evidence that insulin activation of all three signaling components, Viz., IRS-1-dependent PI 3-Kinase, atypical protein kinase C (aPKC) and PKB/Akt is defective in diabetic muscle. These defects are best seen when insulin activation is conducted at both half-maximal and maximal stimulation. Moreover, whereas previous studies had shown that treatment with metformin (Met) alone improves aPKC activation, or that treatment with thiazolidinedione (TZD) alone produces increases in activation of IRS-1/PI3K and aPKC when evaluated at maximal insulin stimulation, we have recently found that combined treatment with Met plus TZD for 6 weeks provokes marked increases in insulin effects on all three signaling factors at both half-maximal and maximal insulin stimulation. This work is being prepared for submission for publication.. We have also evaluated the improvement in insulin signaling in diabetic muscle 4 hours after acute endurance (one-legged) exercise and found that the ...
FIG. 3. Expression of PKC-α, -βI, and -βII isoforms in membrane and cytosolic fractions of DRG in experimental animals. Western blot analysis showed a single band of each isoform in all groups (A). Compared with nondiabetic littermate control mice (Lm) and transgenic mice (Tg), densitometric analysis disclosed reduced expression of membrane α isoform in both diabetic littermate mice (LmDM) and diabetic transgenic mice (TgDM), and the change in diabetic transgenic mice was more severe than in diabetic littermate mice (B). By contrast, cytosolic fraction of α isoform was contrariwise increased to a similar extent in both diabetic transgenic mice and diabetic littermate mice. Treatment with an ARI (fidarestat) corrected these changes in both diabetic groups (LmDM+ARI and TgDM+ARI). There was no change in βI expression in either membrane or cytosolic fraction among all groups. On the other hand, membrane βII expression tended to be elevated in diabetic littermate mice, and the increase was ...
|p|GF 109203X is a potent and selective inhibitor of protein kinase C [1].|/p||p| Protein kinase C (PKC) is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of serine and threon
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The acetylcholine analogue carbachol rapidly activated mitogen-activated protein kinase (MAPK), and caused tyrosine phosphorylation of the adapter protein p52 Shc and the epidermalgrowth factor (EGF) receptor, in human embryonic kidney cells stably expressing m3 muscarinic receptors. The protein kinase C (PKC) inhibitor GF109203X caused a significant partial inhibition of m3 receptor-mediated activation of MAPK. The PKC-independent MAPK activity elicited by carbachol in the presence of GF109203X was reproducibly abolished by AG1478, an inhibitor of EGF-receptor tyrosine kinase activity, and by the Src tyrosine kinase inhibitor PP1. In a subset of these experiments, GF109203X concomitantly increased carbachol-induced tyrosine phosphorylation of p52 Shc and the EGF receptor. In co-stimulation experiments, carbachol and EGF activated MAPK in a non-additive fashion; moreover, EGF-induced association of Shc with the phosphorylated EGF receptor was inhibited by carbachol. This effect of carbachol was ...
Protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and threonine amino acid residues on these proteins, or a member of this family. PKC enzymes in turn are activated by signals such as increases in the concentration of diacylglycerol (DAG) or calcium ions (Ca2+). Hence PKC enzymes play important roles in several signal transduction cascades. The PKC family consists of fifteen isozymes in humans. They are divided into three subfamilies, based on their second messenger requirements: conventional (or classical), novel, and atypical. Conventional (c)PKCs contain the isoforms α, βI, βII, and γ. These require Ca2+, DAG, and a phospholipid such as phosphatidylserine for activation. Novel (n)PKCs include the δ, ε, η, and θ isoforms, and require DAG, but do not require Ca2+ for activation. Thus, conventional and novel PKCs are ...
The protein kinase C (PKC) activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA) activated cell death in androgen-sensitive LNCaP cells but not in androgen-independent DU-145 or PC-3 cells, whose growth was significantly decreased by PKC inhibitors staurosporine and H7. All cell lines had similar le …
Treatment of intact NIH 3T3 cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) causes a rapid redistribution (stabilization) of protein kinase C to the particulate fraction. Part of the enzyme activity stabilized to the membrane fraction in response to TPA can be recovered associated with nuclear-cytoskeletal components. An apparently pure nuclear fraction prepared from NIH 3T3 cells was found to contain 25-30% of the total membrane-associated protein kinase C activity when isolated in the presence of Ca2+. In untreated control cells, most of this activity found with the nuclear fraction can be extracted by chelators. Phorbol easter (TPA) treatment of NIH 3T3 cells induces the tight association of protein kinase C to the nucleus; this tightly bound activity is not dissociable by chelators and can be recovered only by solubilization with detergent. Nuclei purified from untreated human promyelocytic leukemic HL-60 cells contain higher amounts of chelator-stable, detergent-extractable protein ...
Mounting evidence points to a key role of PKC signaling in the pathology of AD, a degenerative disease characterized by loss of synapses and plasticity mechanisms in the brain. The disease is associated with the appearance of extracellular amyloid plaques caused by the mis-cleavage of amyloid precursor protein (APP) and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein [83,84], two pathologies for which PKC involvement has been implicated over the years. But the critical importance of deregulated PKC signaling in AD was recently cemented by the results of an unbiased and comprehensive phosphoproteomic analysis of both human AD postmortem brains and brains from four AD mouse models [85]: PKC substrates accounted for over half of the core molecules that displayed increased phosphorylation in AD compared with control brains. The most robust increase in phosphorylation in AD compared with control brains occurred on MARCKS but also included PKC substrates such as ...
Chromatography of a maize seedling extract on DEAE-cellulose, followed by Octyl-Sepharose yielded a fraction with protein kinase activity which was stimulated by phosphatidylserine plus diolein. The activity was not enhanced by calcium ions but was inhibited by chelating agents and could then be restored by the addition of calcium ions. All these facts indicated that the maize protein kinase was similar to mammalian protein kinase C. The maize enzyme phosphorylated myelin basic protein (MBP) and histone H1, but the MBP-peptide4-14 and protamine were poor substrates for the enzyme. Further purification of the enzyme fraction followed by phosphorylation and SDS-polyacrylamide gel electrophoresis, revealed two labeled bands of Mw 59 and 83 kDa the former of which probably being the protein kinase C.. ...
Translocation of Ca2+/phospholipid-dependent protein kinase (PKC) activity from cytosolic to membrane fractions was assessed in washed human platelet suspensions. Phorbol myristate acetate (PMA) induced a rapid loss of PKC activity from the cytosolic compartment in stirred platelets, which was not accompanied by measurable increases in membrane-associated activity, but was paralleled by a decrease in total cellular enzyme activity (cytosol plus membrane). When platelet aggregation was prevented by not stirring, (i) cytosolic activity was decreased by PMA, (ii) significant and maintained (1-15 min with PMA) increases in membrane-bound PKC were detected, and (iii) the decline in total enzyme activity was markedly slower. In stirred platelets, total and specific inhibition of PMA-induced aggregation by a fibrinogen-derived peptide (RGDS, i.e. Arg-Gly-Asp-Ser) promoted maximal increases in membrane-associated PKC in the presence of PMA and completely prevented the loss in cellular activity. Thrombin ...
alpha-Tocopherol augmentation in human neutrophils was investigated for effects on neutrophil activation and tyrosine phosphorylation of proteins, through its modulation of protein kinase C (PKC) and tyrosine phosphatase activities. Incubation of neutrophils with alpha-tocopherol succinate (TS) resulted in a dose-dependent incorporation into cell membranes, up to 2.5 nmol/2 X 10(6) cells. A saturating dose of TS (40 mumol/l) inhibited oxidant production by neutrophils stimulated with phorbol myristate acetate (PMA) or opsonized zymosan (OZ) by 86 and 57%, as measured by luminol-amplified chemiluminescence (CL). With PMA, TS inhibited CL generation to a similar extent to staurosporine (10 nmol/l) or genistein (100 mumol/l), and much more than Trolox (40 mumol/l). With OZ, TS inhibited CL to a similar extent to Trolox. Neutrophil PKC activity was inhibited 50% or more by TS or staurosporine. the enzyme activity was unaffected by genistein or Trolox, indicating a specific interaction of ...
Recombinant Protein Kinase C, gamma (PRKCG) Protein. Species: Human. Source: Baculovirus infected Insect Cells. Order product ABIN411969.
This study identifies the regulation by PKC of a 40-pS-conductance KNDP subtype, but not a larger-conductance, 70-pS KATP channel of vascular smooth muscle cells. The properties of the 40- and 70-pS channels studied here are consistent with those previously described.11 12 13 14 Suppression of KNDP channel activity by PKC activation was due to an increased time spent in a long-lived interburst closed state, was mimicked by treatment with angiotensin II, and was completely blocked by pretreatment with the PKC inhibitor calphostin C or chelerythrine. The decline in KNDP channel activity due to PKC activation identified in this study may account for the previously reported reduction in whole-cell KATP currents after treatment of vascular myocytes with vasoconstrictors, phorbol esters, or diacylglycerol analogs,1 and therefore, for the contribution of this conductance to the regulation of vascular smooth muscle tone via intracellular signaling cascades involving PKC.. KATP currents have been ...
Among environmental pollutants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) is one of the most potent tumor promoters and teratogens known. The molecular mechanisms responsible for the biological activity of TCDD, however, remain largely unknown. In this report, we show that the first observable effects of TCDD in cultured murine hepatoma cells are a rapid, transient increase in Ca2+ influx and a minor but significant elevation of activated, membrane-bound protein kinase C. These changes are then followed by induction of the immediate early proto-oncogenes c-fos, jun-B, c-jun, and jun-D, and by large increases in AP-1 transcription factor activity. Induction of these changes by TCDD is delayed compared with that by phorbol esters, although the magnitude of the effects caused by both treatments is similar, and both induction processes can be blocked by staurosporine, a protein kinase C inhibitor. In cultured cells, proto-oncogene induction by TCDD appears to be independent of the presence of a
Atypical protein kinase (PK)C isoforms, ζ and λ, have been reported to be activated by insulin via phosphoinositide 3-kinase, and have been suggested to be required for insulin-stimulated glucose transport. Here, we have examined the effects of transiently expressed wild-type (WT), constitutively active (Constit) and kinase-inactive (KI) forms of atypical PKCs, ζ and λ, on haemagglutinin antigen (HAA)-tagged glucose transporter 4 (GLUT4) translocation in rat adipocytes, and compared these effects with each other and with those of comparable forms of conventional (α, β) and novel (δ, ε) PKCs, which have also been proposed to be required for insulin-stimulated glucose transport. KI-PKC-ζ evoked consistent, sizeable (overall mean of 65%) inhibitory effects on insulin-stimulated, but not basal or guanosine-5´-[γ-thio]triphosphate-stimulated, HAA-GLUT4 translocation; moreover, inhibitory effects of KI-PKC-ζ were largely reversed by co-transfection of WT-PKC-ζ. Like KI-PKC-ζ, KI-PKC-λ ...
Studies have also advised the reduction of PKC theta expression may be responsible for inhibition of kit expression in GISTs, hence isnt going to react to KIT staining. Protein kinase C theta kinase inhibitor library for screening is really a novel protein kinase, downstream eector while in the kit signaling process that is associated with T cell activation, signal trans duction, and neuronal dierentiation. Various scientific studies have shown that PKC theta is strongly expressed and is overexpressed in GISTs, but not in other sarcomas. These scientific studies established PKC theta being a diagnostic marker for GIST. In study conducted by kim et al. on 220 GIST tumors, 212 had been positive to PKC theta while KIT was constructive in 216. However, two samples which can be PKC theta good and KIT adverse showed mutation in PDGFRA, indicating that PKC theta may possibly be a practical marker in diagnosing KIT damaging PDGFRA mutation tumors.. Whilst, other investigators feel that PKC theta ...
We have identified the gene encoding the only atypical PKC isoform in Drosophila and show that DaPKC binds directly to Baz and is colocalized with Baz in epithelia and neuroblasts. Apical localization of DaPKC is lost in baz mutants and vice versa, demonstrating that both proteins are mutually dependent on each other for correct localization. In neuroblasts, localization of DaPKC is not only dependent on Baz, but also on Insc. Baz levels are strongly reduced in neuroblasts of insc mutant embryos, most likely because Insc is required for stabilization of Baz (Schober et al. 1999; Wodarz et al. 1999; Yu et al. 2000). Thus, the effect of Insc on DaPKC localization is probably indirect and can be explained by the loss of Baz in insc mutant neuroblasts. Another protein, partner of Insc (Pins), has recently been identified as a binding partner of Insc (Schaefer et al. 2000; Yu et al. 2000). Pins, Baz, and Insc are mutually dependent on each other for correct localization and/or stability (Schaefer et ...
Catalytic domain of the Protein Serine/Threonine Kinase, Novel Protein Kinase C theta. Serine/Threonine Kinases (STKs), Novel Protein Kinase C (nPKC), theta isoform, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The nPKC subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. nPKCs are calcium-independent, but require DAG (1,2-diacylglycerol) and phosphatidylserine (PS) for activity. There are four nPKC isoforms, delta, epsilon, eta, and theta. PKC-theta is selectively expressed in T-cells and plays an important and non-redundant role in several aspects of T-cell biology. ...
Senescence is an irreversible growth arrest phenotype adopted by cells that has a key role in protecting organisms from cancer. There is now considerable interest in therapeutic strategies that reactivate this process to control the growth of cancer cells. Protein kinase C iota (PKCι) is a member of the atypical protein kinase C family and an important downstream mediator in the phosphoinositide pathway. PKCι expression was found to be upregulated in a subset of breast cancers and breast cancer cell lines. Introduction of mutant, oncogenic PIK3CA, but not wild-type PIK3CA, into breast mammary epithelial cells increased both the expression and activation of PKCι. In breast cancer cell lines overexpressing PKCι, depletion of PKCι increased the number of senescent cells, as assessed by senescence-associated β-galactosidase, morphology and bromodeoxyuridine incorporation. This phenomenon was not restricted to breast cancer cells, as it was also seen in glioblastoma cells. Senescence induction ...