• Title/Summary/Keyword: protein kinase C

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MT-2007, Protein Kinase C Inhibitor from Aetinomycetes Isolate No. 2007-18 (방선균 분리주 No 2007-18이 생산하는 Protein Kinase C 저해물질, MT-2007)

  • 안종석;박문수;박찬선;윤병대;민태익;안순철;오원근;이현선;윤병대
    • Microbiology and Biotechnology Letters
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    • v.21 no.1
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    • pp.54-58
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    • 1993
  • During the screening of inhibitors against protein kinase CCPKC) and the bleb formation of K562 cell induced by phorbol ester from microbial secondary metabolites, MT-2007 was purified by solvent extraction, and chromatographic techniques from Actinomycetes isolate No. 2007-18. It showed completely suppression of bleb formation of K562 cell surface induced by phorbol 12.13dibutylate at the concentration of 503.9 11M and ICso on PKC was 31.4 11M. Its structure was postulated as lasalocid A sodium salt by physico-chemical properties and UV, IR. MS, IH-NMR.

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Role of Calcium Influx in mediating the TRH-induced c-fos Gene Expression (갑상선자극 분비 호르몬에 의해 유도되는 c-fos 유전자 발현에서 Ca2+의 역할에 관한 연구)

  • Seung Kirl Ahn;Don
    • The Korean Journal of Zoology
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    • v.36 no.4
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    • pp.487-495
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    • 1993
  • TRH (Thvrotropin-Releasing Hormone) known to regulate the transcription of the TSH (Thyroid-Stimulating Hormones gene in pituitary cells, but little is understood about the mechanism(sl involved. re present study was attempted to elucidate the role of Ca2+ movement through the voltage-gated channels in the regulation of TSH gene transcription. The c-fos is one of immediate early genes and used as model system for the investigation of signaling pathwavs involved in various stimuli. The changes of c-fos mRNA levels were determined after treatment of various agents using Northern and slot hybridization analysis. The c-fos mRNA was rapidly and transiently induced by TRH (about 3-fold) in GH3 cells and this induction was repressed by calcium chelating agent (EGTA), calcium channel blocker (verapamil) anti protein kinase C inhibitor (aminoacridine). The abilities of forskolin (adenvlate cvclase activators, PMA (protein kinase C activator), and A23187 (calcium ionophore) to affect c-ios gene transcription, either alone or in combination with TRH were tested in the same cells. All of them significantly increased the level of c-fos mRUA. However, no additive relationship was observed in all combined treatments except forskolin. These results suggest that TRH action on the c-fos gene activation is mediated by calcium influx as well as through protein kinase C.

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Protein kinase C-mediated Stimulatory Effect of $Ginsenoside-{Rg_1}$ on the Proliferation of SK-HEP-1 (SK-HEP-1 사람 간세포에서 Protein kinase C 신호전달체계를 통한 $인삼사포닌-{Rg_1}$의 DNA 합성 촉진 효과)

  • 공희진;이광열;정은아;이유희;김신일;이승기
    • YAKHAK HOEJI
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    • v.39 no.6
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    • pp.661-665
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    • 1995
  • Ginsenoside-Rg$_{1}$(G-Rg$_{1}$) has been shown to stimulate DNA synthetic activity in SK-HEP-1 cells. This study was therefore designed to determine in SK-HEP-1 cells whether the stimulatory effect of G-Rg$_{1}$ may be mediated by protein kinase C (PKC) which is known to play a key role in the signal transduction pathway leading to the cell proliferation. Using the tn situ PKC assay method, the PKC enzyme activity was determined in SK-HEP-1 cell cultures in response to G-Rg$_{1}$ at 3*10$^{-5}$ M or phorbol 12-myristate 13-acetate(PMA) at 10$^{-6}$ M which in the enzyme activity by 1.5- and 7-fold, respectively. Furthermore, G-Rg$_{1}$, was also able to synergistically increase the enzyme activity by 11-fold m the cell cultures in the presence of PMA. These stimulatory effects of G-Rg$_{1}$ or PMA on the DNA synthetic activity and the PKC activity were ablished by a specific PKC inhibitor, GF109203X. These results suggest that the stimulatory effect of G-Rg$_{1}$ on the DNA synthetic activity may be partly due to stimulation of PKC-mediated signal transduction pathway leading to the proliferation of SK-HEP-1 cells.

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The Involvement of Protein Kinase C and Tyrosine Kinase in Vanadate-induced Contraction

  • Sim, Sang-Soo;Kim, Chang-Jong
    • Archives of Pharmacal Research
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    • v.21 no.3
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    • pp.315-319
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    • 1998
  • Gastric smooth muscle of cats was used to investigate the involvement of protein kinase in vanadate-induced contraction. Vanadate caused a contraction of cat gastric smooth muscle in a dose-dependent manner. Vanadate-induced contraction was totally inhibited by 2 mM EGTA and 1.5 mM $LACI_3$ and significantly inhibited by $10\mu$M verapamil and $1\mu$M nifedipine, suggesting that vanadate-induced contraction is dependent on the extracellular $Ca^{2+}$ concentration, and the influx of extracellular $Ca^{2+}$ was mediated through voltage-dependent $Ca^{2+}$ channel. Both protein kinase C inhibitor and tyrosine kinase inhibitor significantly inhibited the vanadate-induced contraction and the combined inhibitory effect of two protein kinase inhibitors was greater than that of each one. But calmodulin antagonists did not have any influence on the vanadate-induced contraction. On the other hand, both forskolin ($1\mu$M) and sodium nitroprusside ($1\mu$M) significantly inhibited vanadate-induced contraction. Therefore, these results suggest that both protein kinase C and tyrosino kinase are involved in the vanadate-induced contraction which required the influx of extracellular $Ca^{2+}$ in cat gastric smooth muscle, and that the contractile mechanism of vanadate may be different from that of agonist binding to its specific receptor.

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Induction of Maturation Promoting Factor in Runo Oocvtes by Protein Kinase C Activation in uitro. (개구리 난자에서 Protein Kinase C의 활성화에 의한 Maturation Promoting Factor의 생성유도)

  • 유영란;임욱빈
    • The Korean Journal of Zoology
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    • v.35 no.3
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    • pp.277-286
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    • 1992
  • 개구리의 난자로 부터 maturation promoting factor(MPF)를 추출, 부분 분리하여 이들의 활성을 조사하고 이 물질의 생성과 protein kinase C(반KC)와의 관계를 조사하SB다. 성숙된 난자를 분쇄한 후 초원심분리과정을 거쳐 MPF의 crude extract(CE)를 얻은 다음 ultrafiltration (UF)과 고속액체크로마토그라피를 거쳐서 3종류의 분획 (peak 1, 11, and 111)을 얻었다. 이들 분획을 in nitro assay와 autoradiDgraphy를 사용하여 확인한 결과 분획 11에서 MPF 활성이 있는 것을 알았다. 분리 단계에 따라 MPF의 정제도를 Hl histone kinase assay로 조사한 결깍 UF를 거친 것은 CE보다 약 3배로, 분획 11에서는 약 117배로 증가한 것을 확인하였다. 또한 MPF분획의 인산화를 autoradiography로 조사한 결과 45 KD 단백질을 포함한 수종의 난자 단백질이 강하게 인산화되었음을 알 수 있었다. PKC의 활성화가 난자내 MPF의 생성을 유도하는가를 보기 위하여 PKC의 활성제인 12-0-tetradecanoyl phorbol 13 acetate(TPA)를 처리한 난자의 세포질 추출물을 미세주입 법으로 조사한 결과 TPA 처리 후 6시간부터 난자내 MPF의 활성이 나타나는 것을 알 수 있었다. 이러한 결과들은 PKC의 활성화가 MPF의 생성을 유도하고, MPF의 활성화와 함께 일부 단백질들의 인산화를 통하여 궁극적으로 난자 성숙을 촉진했음을 시사한다.

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Immunocytochemical Localization Qf raf Protein Kinase in Cerebrum of Geoclemys reevesii (Gray) (남생이(Geoclemys reevesii) 대뇌에 있어서 raf Protein Kinase의 면역세포화학적 분포)

  • 최원철;문현근
    • The Korean Journal of Zoology
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    • v.33 no.2
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    • pp.141-151
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    • 1990
  • Raf protein kinases and protein kinase C belong to serine/threonine-specific proteins in the cytoplasin, and are similar to each other in functional structure and the aspect of the distribution of celI. The distribution of raf protein kinase in the cerebrum of Geoclemys reevesfi as studied by using the antibodies against a-raf and c-raf protein kinase which induce the expression of raf fainily oncogenes. In general, raf protein kinases were distributed in such restricted regions as the general pallium, hippocampal formation, pdmordiuin hippocampi,nucleus of lateral olfactory tract, basal amygdaloid nucleus, and bed of stria terminalis. Immunological labeling of c-raf protein kinase was more widespread than that of a-raf. However, the intensity of the labeling of c-raf was lower than that of a-raf. The spherical cells of basal amygdaloid nucleus is a ring-like form, because only the cytoplasm was imunolabeled. Especially, c-raf protein kinase occurred in the cells which contained protein kinase C abundandy such as pyramidal cells and Purkinje cells. This suggests that a- and e-raf protein kinases may synegistically induce carclnoma with myc gene which is activated by protein kinase C.

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Activity of Protein Kinase C in Abnormally Proliferated Vascular Endothelial Cells (비정상적인 세포증식이 유도된 혈관 내피세포에서 Protein Kinase C에 대한 활성 분석)

  • Bae, Yong Chan;Park, Suk Young;Nam, Su Bong;Moon, Jae Sul;Choi, Su Jong
    • Archives of Plastic Surgery
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    • v.34 no.1
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    • pp.13-17
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    • 2007
  • Purpose: To understand the pathogenesis of the disease that presents abnormally proliferated vascular endothelial cells, a model of DMH(1,2-dimethylhydrazine)-induced abnormal proliferation of HUVECs(Human Umbilical Vein Endothelial Cells) was made. We indirectly determined that Protein Kinase C(PKC) restricts the cellular proliferation and inhibits the manifestation of growth factor by using several inhibiting substances of the transmitter through our previous studies. Thereupon, we attempted to observe direct enzymatic activities of PKC and its correlation with the abnormal proliferation of vascular endothelial cells. Methods: $10^5$ HUVECs cells were applied to 6 individual well plates in three different groups; A control group cultured without treatment, a group concentrated with $0.75{\times}10^{-8}M$ DMH only, and a group treated with DMH & $5{\times}10^{-9}M$ Calphostin C, inhibitor of PKC. In analyzing the formation of intracellular PKC enzyme, protein separation was performed, and separated protein was quantitatively measured. PKC enzyme reaction was analyzed through Protein Kinase C Assay System (Promega, USA), and the results were analyzed according to Beer's law. Results: Enzymatic activity of PKC presented the highest in all reaction time of a group concentrated only with DMH, and the lowest in the control group. The group treated with DMH and the inhibitor revealed statistically lower enzymatic activity than group only with DMH in all reaction time, although higher than the control group. Conclusion: From the enzymatic aspect, most active and immediate reaction of the PKC was observed in the group concentrated with DMH only. The group treated with DMH & PKC inhibitor showed meaningful decrease. Accordingly, PKC holds a significant role in DMH-induced abnormal proliferation of vascular endothelial cells.

Role of Calcium and Protein Kinase C in Platelet Activating Factor-induced Activation of Peritoneal Macrophages (Platelet Activating Factor에 의한 대식세포의 활성화에 있어서 칼슘과 Protein Kinase C의 역할)

  • Lee, Chung-Soo;Kim, Young-Jun;Shin, Yong-Kyoo;Lee, Kwang-Soo
    • The Korean Journal of Pharmacology
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    • v.29 no.1
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    • pp.107-120
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    • 1993
  • Particulate or soluble stimuli appear to stimulate phagocytic cell's response by the change of $Ca^{2+}$ mobilization and by the activation of protein kinase C. In contrast, it is reported that activation of protein kinase C could attenuate agonist-stimulated elevation of $Ca^{2+}i$ in neutrophils. PAF elicited an increase of $Ca^{2+}i$ in peritoneal macrophages in a dose dependent fashion and $Ca^{2+}$ extrusion was accompanied. PAF-induced elevation of $Ca^{2+}i$ was not affected by TMB-8, verapamil and TTX. TEA stimulated PAF-induced mobilization of $Ca^{2+}i$ and delayed lowering of $Ca^{2+}i$. Five mM EGTA almost completely inhibited PAF-induced mobilization of $Ca^{2+}i$. After the addition of PAF, membrane permeability was markedly increased up to 5 min and then slowly increased. PAF-induced LDH release was slightly decreased by EGTA plus TMB-8. PAF-stimulated superoxide generation was inhibited by EGTA, TMB-8 and verapamil but not affected by TTX and TEA. PAF-induced elevation of $Ca^{2+}i$, increased membrane permeability and superoxide generation were inhibited by IQSP, chlorpromazine and propranolol. PAF-induced LDH release was significantly inhibited by chlorpromazine and minimally decreased by propranolol. After the pretreatment with PMA, the stimulatory effect of PAF on the elevation of $Ca^{2+}i$ and LDH release in macrophages was significantly decreased. These results suggest that PAF may exert the stimulatory action on peritoneal macrophages of mouse by the elevation of $Ca^{2+}i$ and by the activation of protein kinase C. Preactivation of protein kinase C appears to attenuate the stimulatory action of PAF on macrophage response.

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The Role of Protein Kinase C for Prolactin Secretion in Chicken Primary Pituitary Cell Culture (산란계의 뇌하수체 세포배양에서 Prolactin의 생성에 관계하는 Protein Kinase C의 역할)

  • 선상수
    • Korean Journal of Poultry Science
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    • v.23 no.3
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    • pp.113-119
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    • 1996
  • A series of experiments were conducted to investigate the role of protein kinase C (PKC) as a second messenger in vasoactive intestinal peptide (VIP) mediated prolactin secretion. Primary pituitary cells (106 cells/treatment) were separated from laying hens and incubated in M-199 with 5% chicken serum and 5% fetal calf serum. The VIP(0.1 $\pi$M) treatment enhanced prolactin Secretion into media upto 9-fold during 48-h incubation. The phorbol 12-myristate 13-acetate (PMA), a PKG agonist, increased prolactin secretion upto 2-fold at 0.1 nM PMA (P<0.01), and the prolactin secretion was not significantly higher than this concentration. Staurosporine (ST; 1.0$\pi$M) a PKC antagonist, decreased by 70% of 0.1 $\pi$M VIP-stimulated prolactin secretion and by 48% of 10 ${\mu}$M PMA-stimulated prolactin secretion (P<0.01). However, pituitary cell prolactin content did not differ in any treatment (P>0.05). In conclusion, these results indicate that the PKC second messenger system is involved in VIP-stimulated prolactin release in chicken primary pituitary cell culture.

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Ginsenosides Promote Proliferation of Cultured Ovarian Germ Cells Involving Protein Kinase C-mediated System in Embryonic Chickens

  • Liu, Hongyun;Zhang, Caiqiao
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.7
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    • pp.958-963
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    • 2006
  • The effect of ginsenosides (GS) on germ cell proliferation was evaluated with a chicken ovarian germ-somatic cell coculture model and the mechanism involving protein kinase C (PKC) pathway was investigated. Ovarian cells were cultured in serum-free McCoy's 5A medium and challenged with GS alone or in combinations with PKC activator (phorbol 12-myristate 13-acetate, PMA) or inhibitor ($H_7$) for 48 h. The number of germ cells was counted and the proliferating cells were identified by immunocytochemistry of proliferating cell nuclear antigen (PCNA). Results showed that GS significantly increased germ cell proliferation and this stimulating effect was further increased by PMA, but inhibited by H7, in a dose-dependent manner. Moreover, GS-elevated PCNA expression and the PCNA -labeling index of germ cells displayed similar changes with the increased numbers of germ cells. These results indicated that GS stimulated proliferation of ovarian germ cells with involvement of the PKC-mediated system.