• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.269-273
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• 2001

The expression of protein kinase C(PKC) isoforms and nitric oxide synthase (NOs) isoforms was studied in the equine vomeronasal organ(VNO), a pheromone receptor organ, using immunohistochemistry. All PKC isoforms including PKC $\alpha$, ${\beta}I$, $\delta$, and $\theta$ were detected in the supporting cells, sensory receptor cells, and basal sensory epithelial cells, while constitutive PKC $\alpha$ and ${\beta}I$ were stained more intensely than novel PKC $\delta$ and ${\theta}$. There was also a varying degree of immunostaining for PKCs in the glandular acini and VNO nerve. Constitutive neuronal and endothelial NOSs, and inducible NOS were detected in the VNO sensory epithelia. There was intense immunoreactivity for endothelial NOS in the VNO sensory epithelia but weak reactivity for neuronal NOS, while inducible NOS showed little immunoreactivity in the adjacent section. These findings suggest that both PKCs and NOSs may be involved in the process of pheromone reception in the horse. Constitutive isoforms of these enzymes may play a more important role in signal trasduction in the VNO of the horse.

• Molecules and Cells
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• v.21 no.1
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• pp.21-28
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• 2006

The interferon-induced, double-stranded RNA (dsRNA)-dependent protein kinase PKR plays a key role in interferon-mediated host defense against viral infection, and is implicated in cellular transformation and apoptosis. We have isolated a cDNA of simian PKR encoding a product with 83% amino acid identity to the human homolog and showed that PKR expression is significantly attenuated in the Vero E6 African green monkey kidney cells devoid of type I interferon genes. A variant form of PKR lacking the exon 12 in the kinase domain is produced in these cells, presumably from an alternatively spliced transcript. Unlike wild type PKR, the variant protein named PKR-${\Delta}E12$ is incapable of auto-phosphorylation and phosphorylation of eIF2-${\alpha}$, indicating that the kinase sub-domains III and IV embedded in exon 12 are indispensable for catalytic function. PKR-${\Delta}E12$ had no dominant negative effect but was weakly phosphorylated in trans by wild type PKR.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.518-524
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• 2000

We examined the modulation of protein kinase C (PKC) subtypes during apoptosis induced by ginsenoside Rh2 (G-Rh2) in human neuroblastoma SK-N-Bl(2) and rat glioma C6Bu-1 cells. Apoptosis induced by C-Rh2 in both cell lines was confirmed, as indicated by DNA fragmentation and in situ strand breaks, and characteristic morphological changes. During apoptosis induced by G-Rh2 in SK-N-BE(2) cells, PKC subtypes $\alpha$, $\beta$ and $\gamma$ were progressively increased with prolonged treatment, whereas PKC $\delta$ increased transiently at 3 and 6 h and PKC $\varepsilon$ was gradually down-regulated after 6 h following the treatment. On the other hand, PKC subtype $\beta$ markedly increased at 24 h when maximal apoptosis was achieved. In C6Bu-l cells, no significant changes in PKC subtypes $\alpha$, $\gamma$, $\delta$, $\varepsilon$ and $\beta$ were observed during apoptosis induced by G-Rh2. These results suggest the evidence for a possible role of PKC subtype in apoptosis induced by G-Rh2 in SK-N-BE(2) cells but not in C6Bu-1 cells, and raise the possibility that G-Rh2 may induce apoptosis via different pathways interacting with or without PKC in different cell types.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.61-68
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• 2008

Purpose: Protein kinase C (PKC) is a member of a family of serine/threonine kinases that are activated by diacylglycerol (DG) and PKC stimulants. PKC play a key role in signal transduction, including muscle contraction, cell migration, apoptosis, cell proliferation and differentiation. However, the mechanism relating mitogen-activated protein kinases (MAPKs) and PKC, especially in the volume-dependent hypertensive state, remains unclear. Methods: In the present study, I investigated the relationship between PKC and MAPKs for isometric contraction, PKC translocation, and enzymatic activity from normotensive sham-operated rats (NSR) and aldosterone-analogue deoxycorticosterone acetate (DOCA) hypertensive rats (ADHR). Results: Systolic blood pressure was significantly increased in ADHR than in NSR. Physiological salt solution (PSS)-induced resting tension and the intracellular $Ca^{2+}$ concentration ([$Ca^{2+}{_i}$]) were different in the ADHR and NSR. The expression of PKC$\alpha$, PKC$\beta$II, PKC$\delta$, PKC$\varepsilon$ and PKC$\xi$ were different between the cytoplasmic and membranous fractions. However, expression of the PKC isoforms did not differ for the ADHR and NSR. The use of 12-deoxyphorbol 13-isobutyrate (DPB, a PKC stimulant) induced isometric contraction in $Ca^{2+}$-free medium, which was diminished in muscle strips from ADHR as compared to NSR. Increased vasoconstriction and phosphorylation induced by the use of 1 ${\mu}$M DPB were inhibited by treatment with 10 ${\mu}$M PD098059 and 10 ${\mu}$M SB203580, inhibitors of extracellular-regulated protein kinase 1/2 (ERK1/2) and p38 MAPK from ADHR, respectively. Conclusion: These results suggest that the development of aldosterone analogue-induced hypertension is associated with an altered blood pressure, resting tension, [$Ca^{2+}{_i}$], and that the $Ca^{2+}$-independent contraction evoked by PKC stimulants is due to the activation of ERK1/2 and p38 MAPK in volume-dependent hypertension. Therefore, it is suggested that PKC activity affects volume-dependent hypertension and the need to develop cardiovascular disease-specialized physical therapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.445-454
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• 2007

Background: Phosphatidic acid(PA), an important second messenger, is involved in inflammation. Notably, cell-cell interactions via adhesion molecules playa central role in inflammation. This thesis show that PA induces expression of intercellular adhesion molecule-1(ICAM-1) on macrophages and describe the signaling pathways. Materials and methods: Macrophages were cultured in the presence of 10% FBS and assayed cell to cell adhesion using HUVEC. For the gene and protein analysis, RT-PCR, Western blot and flow cytometry were performed. In addition, overexpressed cell lines for dominant negative PKC-${\delta}$ mutant established and tested their effect on the promoter activity and expression of ICAM-1 protein by PA. Results: PA-activated macrophages significantly increased adhering to human umbilical vein endothelial cell and this adhesion was mediated by ICAM-1. Pretreatment with rottlerin(PKC-${\delta}$ inhibitor) or expression of a dominant negative PKC-${\delta}$ mutant, but not Go6976(classical PKC-${\alpha}$ inhibitor) and myristoylated PKC-${\xi}$ inhibitor, attenuated PA-induced ICAM-1 expression. The p38 mitogen-activated protein kinase(MAPK) inhibitor blocked PA-induced ICAM-1 expression in contrast, ERK upstream inhibitor didn't block ICAM-1. Conclusion: These data suggest that PA-induced ICAM-1 expression and cell-cell adhesion in macrophages requires PKC-${\delta}$ activation and that PKC-${\delta}$ activation is triggers to sequential activation of p38 MAPK.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.63-63
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• 1993

Phospoinositide-specific phospholipase C (PLC)는 세포막의 phosphoinositide를 분해하여 inositol phosphates와 diacylglycerol을 전달하는데 핵심적인 효소이다. PLC는 분자량과 1차구조의 비교에 의하여 type (PLC-$\beta$, ${\gamma}$, $\delta$)로 구분되며, 각 type마다 2-4종의 subtype이 존재하고 PLC isozyme들에 대한 현재가지의 각종 신호 전달 및 조절에 대한 연구를 종합하면: (1) PLC-$\beta$ type은 G-protein과 연결되어 신호를 전달받고, (2) PLC-${\gamma}$ type은growth factor receptor tyrosine kinase에 의하여 인산화 되어 활성화됨으로, 세포의 성장 신호를 전달하며. (3) PLC-$\delta$ type에 대한 신호 전달이나 조절은 밝혀지지 않고 있다.

• Journal of Life Science
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• v.8 no.6
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• pp.638-647
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• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5687-5692
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• 2013

Type 2 diabetes mellitus (T2DM) has contributed to advanced breast cancer development over the past decades. However, the mechanism underlying this contribution is poorly understood. In this study, we determined that high glucose enhanced proteasome activity was accompanied by enhanced proliferation, migration and invasion, as well as suppressed apoptosis, in human breast cancer MCF-7 cells. Proteasome inhibitor bortezomib (BZM) pretreatment mitigated high glucose-induced MCF-7 cell growth and invasion. Furthermore, high glucose increased protein kinase C delta ($PKC{\delta}$)-phosphorylation. Administration of the specific $PKC{\delta}$ inhibitor rottlerin attenuated high glucose-stimulated cancer cell growth and invasion. In addition, $PKC{\delta}$ inhibition by both rottlerin and $PKC{\delta}$ shRNA significantly suppressed high glucose-induced proteasome activity. Our results suggest that $PKC{\delta}$-dependent ubiquitin proteasome system activation plays an important role in high glucose-induced breast cancer cell growth and metastasis.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.208-216
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• 2010

Fusarium verticillioides is an important pathogen of maize, being responsible for ear rots, stalk rots, and seedling blight worldwide. During the past decade, F. verticillioides has caused several severe epidemics of maize seedling blight in many areas of China, which lead to significant losses. In order to understand the molecular mechanisms regulating fungal development and pathogenicity in this pathogen, we isolated and characterized the gene fpk1 (GenBank Accession No. EF405959) encoding a homolog of the cAMP-dependent protein kinase catalytic subunit, which included a 1,854-bp DNA sequence from ATG to TAA, with a 1,680-bp coding region, and three introns (lengths: 66 bp, 54 bp, and 54 bp), and the predicated protein precursor had 559 aa. The mutant ${\Delta}fpk1$, which was disrupted of the fpkl gene, showed reduced vegetative growth, fewer and shorter aerial mycelia, strongly impaired conidiation, and reduced spore germination rate. After germinating, the fresh hypha was stubby and lacking of branch. When inoculated in susceptible maize varieties, the infection of the mutant ${\Delta}fpk1$ was delayed and the infection efficiency was reduced compared with that of the wild-type strain. AU this indicated that gene fpk1 participated in hyphal growth, conidiophore production, spore germination, and virulence in F. verticillioides.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1177-1182
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• 2012

Protein kinase C (PKC) has been implicated in carcinogenesis and displays variable expression profiles during cancer progression. Studies of dietary phytochemicals on cancer signalling pathway regulation have been conducted to search for potent signalling regulatory agents. The present study was designed to evaluate any suppressive effect of maslinic acid on PKC expression in human B-lymphoblastoid cells (Raji cells), and to identify the PKC isoforms expressed. Effects of maslinic acid on PKC activity were determined using a PepTag$^{(R)}$ assay for non-radioactive detection of PKC. The highest expression in Raji cells was obtained at 20 nM PMA induced for 6 hours. Suppressive effects of maslinic acid were compared with those of four PKC inhibitors (H-7, rottlerin, sphingosine, staurosporine) and two triterpenes (oleanolic acid and ursolic acid). The $IC_{50}$ values achieved for maslinic acid, staurosporine, H-7, sphingosine, rottlerin, ursolic acid and oleanolic acid were 11.52, 0.011, 0.767, 2.45, 5.46, 27.93 and $39.29\;{\mu}M$, respectively. Four PKC isoforms, PKC ${\beta}I$, ${\beta}II$, ${\delta}$, and ${\zeta}$, were identified in Raji cells via western blotting. Maslinic acid suppressed the expression of PKC ${\beta}I$, ${\delta}$, and ${\zeta}$ in a concentration-dependent manner. These preliminary results suggest promising suppressive effects of maslinic acid on PKC activity in Raji cells. Maslinic acid could be a potent cancer chemopreventive agent that may be involved in regulating many downstream signalling pathways that are activated through PKC receptors.