• Title/Summary/Keyword: Protein kinase c isozymes

Search Result 19, Processing Time 0.02 seconds

Protein Kinase C (PKC) in Cellular Signalling System: Translocation of Six Protein Kinase C Isozymes in Human Prostate Adenocarcinoma PC-3 Cell Line (세포신호계에 있어서 Protein Kinase C: 사람의 전입선 adenocarcinoma PC-3 세포내의 여섯개의 Protein kinase C 동립효소의 translocation)

  • Park, Won-Chul;Ahn, Chang-Ho
    • The Korean Journal of Zoology
    • /
    • v.36 no.4
    • /
    • pp.439-451
    • /
    • 1993
  • Protein kinase C isozymes in a human prostate adenocarcinoma PC-3 cell line were characterized. Immunoreactive bands and immunocytochemical stains were obsenred in PC-3 cells with antibodies raised against protein kinase C ${\alpha}$, ${\beta}$, ${\gamma}$, $\delta$, $\varepsilon$, and ζ types, respectively. Protein kinase C ${\alpha}$ corresponded to a immunoreactive band at a molecular weight of 80,000-dalton, whereas molecular weights of other immunoreactive isozvmes of protein kinase C were detected at 68,000-dalton. Protein kinHse C $\delta$ and ζ antibodies detected additional bands at 55,000-dalton and 80,000-dalton, respectively Immunocvtochemical study confirmed the results of the immunoblotting experiments qualitatively: all six protein kinase C isozymes were detected in the cytoplasm of PC-3 cells. Translocation of protein kinase C in PC-3 cells were also examined with phorbol 12-myristate 13-acetate (PMA), bryostatin 2, diolein, and 1-oleoyl-2-acetyl glycerol (OAG). Differential reactions of protein kinase C isozvmes to these activators were obsenred. When PC-3 cells were treated with 10mM bryostatin 2, protein kinase C isozyme u was translocated into the nucleus, whereas s type was translocated into the plasma membrane and the nucleus. Protein kinase C ${\alpha}$ and ζ types were translocated into the nucleus following the treatment with 101M diolein, whereas protein kinase C ${\alpha}$, ${\beta}$, ${\gamma}$, and $\varepsilon$ types were translocated into the nucleus by the treatment with 10mM OAG. Protein kinase C ${\alpha}$ and $\varepsilon$ types were translocated into the nucleus in the presence of 100nM PMA. Protein kinase C $\delta$ type was translocated to the nuclear membrane by these activators, however, only PMA-induced translocation was inhibited by protein kinase C inhibitor, 1-(5-isoquinolinesulfonyll-2-methvlpiperazine dihvdrochloride (H7) . H7 inhibited translocation of protein kinase C ${\alpha}$ type induced by PMA, ${\beta}$ type by OAG and s type by PMA and OAG, whereas it did not affect translocations induced by bryostatin and diolein, respectively. These results suggest that there exist six isoformes of protein kinase C (${\alpha}$, ${\beta}$, ${\gamma}$, $\delta$, $\varepsilon$ and ζ types) in PC-3 cells and that each of these isozvmes distinctivelv reacts to bryostatin, diolein, OAG and PMA, in part due to an altered molecular size and conceivably discrete binding site(s).

  • PDF

Studies on the Differentiation of Skeletal Muscle Cells in vitro:Protein Kinase C in the Differentiation of Skeletal Muscle Cells (근세포 분화에 관한 연구 : 근세포 분화에 있어서 Protein Kinase C)

  • 최원철;김한도;김정락
    • The Korean Journal of Zoology
    • /
    • v.34 no.2
    • /
    • pp.131-141
    • /
    • 1991
  • Treating 12-O-tetradecanoyIphorboI 13-acetate -TPA) or platelet~derived growth factor(PDGF), the signal transduction of protein Idnase C (PKC) is occurred by the phosphoryladon. However the targeting proteins phosphorylated by PKC were found to be different proteins in molecular weights when WA or PDGF wa~ treated to the myoblast. In the WA-treated myoblast cells, the protein of Mr. 20 I(d was phosphorylated. In the PDGF-treated cells, the protein of Mr. 40 Kd was phosphrylated, while the protein of Mr. 20 Kd which phosphorylated in the WA-treatment was dephosphorylated. These results indicate that not only WA and PDGF &e different in activating the signal transduction pathways, but also they may involve in the down reguladon of PI(C during the long-term treatment But PDGF gave rise more rapidly down reguladon than in the case of WA. Using immunocytochemical approach, two disdnct PKC isozymes, PKC II and PKC III, have been localized in cytoplasm and both cytoplasm and nuclsolus, respectively. Ther'efore, the expression of two types of PKC in the myoblast suggests that the isozymes of PKC may involve in each different pathway of signal transduction or down-reguladon.

  • PDF

Sequence Analysis and Potential Action of Eukaryotic Type Protein Kinase from Streptomyces coelicolor A3(2)

  • Roy, Daisy R.;Chandra, Sathees B.C.
    • Genomics & Informatics
    • /
    • v.6 no.1
    • /
    • pp.44-49
    • /
    • 2008
  • Protein kinase C (PKC) is a family of kinases involved in the transduction of cellular signals that promote lipid hydrolysis. PKC plays a pivotal role in mediating cellular responses to extracellular stimuli involved in proliferation, differentiation and apoptosis. Comparative analysis of the PKC-${\alpha},{\beta},{\varepsilon}$ isozymes of 200 recently sequenced microbial genomes was carried out using variety of bioinformatics tools. Diversity and evolution of PKC was determined by sequence alignment. The ser/thr protein kinases of Streptomyces coelicolor A3 (2), is the only bacteria to show sequence alignment score greater than 30% with all the three PKC isotypes in the sequence alignment. S.coelicolor is the subject of our interest because it is notable for the production of pharmaceutically useful compounds including anti-tumor agents, immunosupressants and over two-thirds of all natural antibiotics currently available. The comparative analysis of three human isotypes of PKC and Serine/threonine protein kinase of S.coelicolor was carried out and possible mechanism of action of PKC was derived. Our analysis indicates that Serine/ threonine protein kinase from S. coelicolor can be a good candidate for potent anti-tumor agent. The presence of three representative isotypes of the PKC super family in this organism helps us to understand the mechanism of PKC from evolutionary perspective.

Translocation of Protein Kinase C Isozymes in the Breast Cancer Cell Line (유방 암세포에서 Protein Kinase C 동위효소의 전위)

  • Won Chul Choi;Joo Young Son;Seok Jin Seo
    • Journal of Life Science
    • /
    • v.8 no.6
    • /
    • pp.638-647
    • /
    • 1998
  • Protein Kinase C (PKC) activators, phorbol 12-myristate 13-acetate (PMA), bryostatin, and dioctanoyl glycerol (DiC8), induce translocation of PKC isozymes from cytoplasm to plasma membrane or into nucleus. The activated PKC negatively modulates growth of human breast cancer cells. Antiproliferative effect and translocation of PKC were investigated in MCF-7 cells. The translocation of activated PKC isozymes by PMA, bryostatin and DiC8 was occurred at the various different regions in MCF-7 cell. PKC $\alpha$ and $\beta$ could be translocated to the nucleus or the nuclear mem-brane, and PKC $\delta$and $\varepsilon$ to cell membrane by PMA while DiC8 and bryostatin induced the translocation of PKC $\alpha$ and $\beta$ to the nucleus or plasma membrane, respectively. In the antiproliferative effect of PKC activators, PMA ($IC_{50}$/ values of 1.2$\pm$0.3nM) and DiC8 ($IC_{50}$/ values of 5.0$\pm$1.1$\mu$M) inhibited the cell growth. Bryostatin also inhibited the cell growth but to a much less degree than one obser-ved with PMA : 16% growth reduction by 100nM bryostatin. However, PMA treated with bryostatin induced gro-wth inhibition, but PMA with DiC8 at 10$\mu$M was not effective. These results suggest that each PKC isozyme is tran-slocated to various specific sites, and that especially, PKC $\alpha$ isozyme plays an important role in control of antiprolife-raive function of cell growth.

  • PDF

Growht Ingibition of Human Ovarian Cancer Cells by Differential Modulation of Protein Kinase A Isozymes

  • Seo, Jin;Kim, Se-Nyun;Lee, Gap-Ryol;Kim, So-Young;Park, Sang-Dal;Hong, Seung-Hwan
    • Animal cells and systems
    • /
    • v.1 no.2
    • /
    • pp.389-394
    • /
    • 1997
  • We examined the effect of modulation of PKA isozymes on the growth of human ovarian cancer cells. Three ovarian cancer cell lines, 2774, SK-OV-3, and OVCAR-3, were examined in this study. The treatment of 5 uM 8-CI-cAMP, which has been known to down-regulate RI (or type 1 PKA) and up-regulate RII (or type II PKA), markedly inhibited the growth of all cell lines (50-80% at day 6). To test whether alteration in PKA regulatory subunits level can change the growth characteristics of ovarian cancer cells, we introduced RIIB- expression construct and Rla antisense-expression construct into 2774 cells. The overexpression of RIIB down-regulated Rla protein, and the antisense-expression of Rla up-regulated RIIB protein, showing that the intracellular levels of RI and RII are reciprocally regulated. In both cases, cell growth was reduced by 30% at day 2. These results indicate that the growth of ovarian cancer cells is controlled by the signals from PKA isozymes, and the modulation of PKA isozymes can be employed for the human ovarian cancer therapy.

  • PDF

Regulation of Phosphoinositide-specific Phospholipase C-$\gamma$ Isozyme

  • Bae, Yun-Soo
    • Proceedings of the Korean Biophysical Society Conference
    • /
    • 1998.06a
    • /
    • pp.17-17
    • /
    • 1998
  • Although the activation mechanism of PLC-${\gamma}$ isozyme by protein tyrosine kinase (PTK) is well established, several lines of evidence indicate that PLC-${\gamma}$ isozymes can be activated directly by several lipid-derived second messengers In the absence of tyrosine phosphorylation.(omitted)

  • PDF

Phospholipase D isozymes mediate epigallocatechin gallate-induced cyclooxygenase-2 expression in astrocyte cells

  • Kim, Shi-Yeon;Min, Kyoung-Jin;Joe, Eun-Hye;Min, Do-Sik
    • Proceedings of the Korean Society of Plant Biotechnology Conference
    • /
    • 2004.10a
    • /
    • pp.74-79
    • /
    • 2004
  • Little is known about the effect of epigallocatechin-3 gallate (ESCG), a major constituent of green tea, on the expression of cyclooxygenase (COX)-2. Here, we studied the role of phospholipase D (PLD) isozymes in EGCG-induced COX-2 expression. Stimulation of human astrocytoma cells (U87) with EGCG induced formation of phosphatidylbutanol, a specific product of PLD activity, and synthesis of COX-2protein and its product, prostaglandin $E_2$ ($PGE_2$). Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed EGCG-induced COX-2 expression and $PGE_2$ synthesis. Furthermore, evidence that PLD was involved in EGCG-induced COX-2 expression w3s provided by the observations that COX-2 expression was stimulated by over-expression of PLD1 or PLD2 isozymes and treatment with phosphatidic acid(PA), and that prevention of PA dephosphorylation by 1-propranolol significantly potentiated COX-2expression Induced by EGCG. EGCG induced activation of p38 mitogen-activated protein kinase (p38MAPK), and specific Inhibition of p38 MAPK dramatically abolished EGCG-Induced PLD activation, COX-2 expression, and $PGE_2$ formation. Moreover, protein kinase C (PKC) inhibition suppressed EGCG-induced p38 MAPK activation, COX-2 expression, and $PGE_2$ accumulation. The same pathways as those obtained in the astrocytoma cells were active in primary rat astrocytes, suggesting the relevance of the findings. Collectively, our results demonstrate for the first time that PLD isozymes mediate EGCG-induced COX-2 expression through PKC and p38 in immortalized astroglial line and normal astrocyte cells.

  • PDF

Protein Kinase $C-{\alpha}$ Regulates Toll-like Receptor 4-Mediated Inducible Nitric Oxide Synthase Expression

  • Lee, Jin-Gu;Chin, Byung-Rho;Baek, Suk-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.34 no.1
    • /
    • pp.28-35
    • /
    • 2008
  • Purpose: The nitric oxide (NO) release by inducible nitric oxide synthase (iNOS) is the key events in macrophage response to lipopolysaccharide (LPS) which is suggested to be a crucial mediator for inflammatory and innate immune responses. NO is an important mediator involved in many host defense action and may also lead to a harmful host response to bacterial infection. However, given the importance of iNOS in a variety of pathophysiological conditions, control of its expression and signaling events in response to LPS has been the subject of considerable investigation. Materials and Methods: The Raw264.7 macrophage cell line was used to observe LPS-stimulated iNOS expression. The expression of iNOS is observed by Western blot analysis and real-time RT-PCR. Protein kinase C $(PKC)-{\alpha}$ overexpressing Raw264.7 cells are established to determine the involvement of $PKC-{\alpha}$ in LPS-mediated iNOS expression. $NF-{\kappa}B$ activity is measured by $I{\kappa}B{\alpha}$ degradation and $NF-{\kappa}B$ luciferase activity assay. Results: We found that various PKC isozymes regulate LPS-induced iNOS expression at the transcriptional and translational levels. The involvement of $PKC-{\alpha}$ in LPS-mediated iNOS induction was further confirmed by increased iNOS expression in $PKC-{\alpha}$ overexpressing cells. $NF-{\kappa}B$ dependent transactivation by LPS was observed and $PKC-{\alpha}$ specific inhibitory peptide abolished this activation, indicating that $NF-{\kappa}B$ activation is dependent on $PKC-{\alpha}$. Conclusion: Our data suggests that $PKC-{\alpha}$ is involved in LPS-mediated iNOS expression and that its downstream target is $NF-{\kappa}B$. Although $PKC-{\alpha}$ is a crucial mediator in the iNOS regulation, other PKC isozymes may contribute LPS-stimulated iNOS expression. This finding is needed to be elucidated in further study.

Molecular Mechanisms of Protein Kinase C-induced Apoptosis in Prostate Cancer Cells

  • Gonzalez-Guerrico, Anatilde M.;Meshki, John;Xiao, Liqing;Benavides, Fernando;Conti, Claudio J.;Kazanietz, Marcelo G.
    • BMB Reports
    • /
    • v.38 no.6
    • /
    • pp.639-645
    • /
    • 2005
  • Protein kinase C (PKC) isozymes, a family of serine-threonine kinases, are important regulators of cell proliferation and malignant transformation. Phorbol esters, the prototype PKC activators, cause PKC translocation to the plasma membrane in prostate cancer cells, and trigger an apoptotic response. Studies in recent years have determined that each member of the PKC family exerts different effects on apoptotic or survival pathways. $PKC{\delta}$, one of the novel PKCs, is a key player of the apoptotic response via the activation of the p38 MAPK pathway. Studies using RNAi revealed that depletion of $PKC{\delta}$ totally abolishes the apoptotic effect of the phorbol ester PMA. Activation of the classical $PKC{\alpha}$ promotes the dephosphorylation and inactivation of the survival kinase Akt. Studies have assigned a pro-survival role to $PKC{\varepsilon}$, but the function of this PKC isozyme remains controversial. Recently, it has been determined that the PKC apoptotic effect in androgen-dependent prostate cancer cells is mediated by the autocrine secretion of death factors. $PKC{\delta}$ stimulates the release of $TNF{\alpha}$ from the plasma membrane, and blockade of $TNF{\alpha}$ secretion or $TNF{\alpha}$ receptors abrogates the apoptotic response of PMA. Molecular analysis indicates the requirement of the extrinsic apoptotic cascade via the activation of death receptors and caspase-8. Dissecting the pathways downstream of PKC isozymes represents a major challenge to understanding the molecular basis of phorbol ester-induced apoptosis.