• 제목/요약/키워드: G proteins

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Immunohistochemical Prognostic Factors in Soft Tissue Sarcoma (연부조직 육종에서 면역조직화학적 예후인자)

  • Choi, Kyung-Un;Kim, Jeung-Il;Moon, Nam-Hoon
    • The Journal of the Korean bone and joint tumor society
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    • v.14 no.2
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    • pp.106-118
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    • 2008
  • Purpose: Disturbed cell cycle regulatory proteins are key events underlying the development and/or progression of human malignancies. The aim of this study is to evaluate the protein expression status involved in G1/S cell cycle in human soft tissue sarcoma. Materials and Methods: We simultaneously evaluated the expression of Cyclin D1, Cyclin E, CDK4, CDK2, p16, p27, Rb, E2F1, p53 and Ki-67 by immunohistochemistry in 43 cases of soft tissue sarcoma Results: The Cyclin D1, Cyclin E, CDK4, CDK2, E2F1, and p53 were expressed in 25 (58.1%), 18 (41.9%), 13 (30.2%), 33 (76.7%), 20 (46.5%), and 18 cases (41.9%). The p16, p27, and Rb expressions were decreased in 26 (60.5%), 22 (51.2%) and 19 cases (44.2%). All of the cases showed alterations of more than one out of the above proteins. The increased Cyclin E expression and Ki-67 labeling index (LI) were significantly associated with histologic grade. The Cyclin E and E2F-1 expressions were increased in relapsed cases and the CDK4 expression was increased in cases of metastasis. Conclusion: Alterations of G1/S cell cycle regulatory proteins may play an important role in the tumoriogensis of soft tissue sarcomas. Our results suggest that increased expressions of Cyclin E, E2F1, and CDK4 were associated with tumor relapse or metastasis and could be considered as parameters of prognosis of soft tissue sarcoma.

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Expression of the Floral Repressor miRNA156 is Positively Regulated by the AGAMOUS-like Proteins AGL15 and AGL18

  • Serivichyaswat, Phanu;Ryu, Hak-Seung;Kim, Wanhui;Kim, Soonkap;Chung, Kyung Sook;Kim, Jae Joon;Ahn, Ji Hoon
    • Molecules and Cells
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    • v.38 no.3
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    • pp.259-266
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    • 2015
  • The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in Arabidopsis thaliana, but the mechanisms regulating its transcription remain unclear. Here, we show that two AGAMOUS-like proteins, AGL15 and AGL18, act as positive regulators of the expression of MIR156. Small RNA northern blot analysis revealed a significant decrease in the levels of mature miR156 in agl15 agl18 double mutants, but not in the single mutants, suggesting that AGL15 and AGL18 co-regulate miR156 expression. Histochemical analysis further indicated that the double mutants showed a reduction in MIR156 promoter strength. The double mutants also showed reduced abundance of pri-miR156a and pri-miR156c, two of the primary transcripts from MIR156 genes. Electrophoretic mobility shift assays demonstrated that AGL15 directly associated with the CArG motifs in the MIR156a/c promoters. AGL18 did not show binding affinity to the CArG motifs, but pull-down and yeast two-hybrid assays showed that AGL18 forms a heterodimer with AGL15. GFP reporter assays and bimolecular fluorescence complementation (BiFC) showed that AGL15 and AGL18 co-localize in the nucleus and confirmed their in vivo interaction. Overexpression of miR156 did not affect the levels of AGL15 and AGL18 transcripts. Taking these data together, we present a model for the transcriptional regulation of MIR156. In this model, AGL15 and AGL18 may form a complex along with other proteins, and bind to the CArG motifs of the promoters of MIR156 to activate the MIR156 expression.

A New Rhabdovirus (HRV-like) Isolated in Korea from Cultured Japanese Flounder Paralichthys olivaceus (양식산 넙치로부터 HRV-like Rhabdovirus의 분리)

  • Oh, Myung-Joo;Choi, Tae-Jin
    • Journal of fish pathology
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    • v.11 no.2
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    • pp.129-136
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    • 1998
  • In March 1997, a new rhabdovirus was isolated from moribund cultured Japanese flounder Paralichthys olivaceus in sea water tank and cage culture systems in Kyung-Nam and Chun-Nam province, Korea. At temperature $15^{\circ}C$ the virus replicated and induced cytopathic effects (CPE), which progressed to eventual cytolysis, in susceptible cell lines, including RTG-2 and EPC. The CHES-214 cell line was refractory. Virus particles were bullet-shaped and measured $70nm{\times}100$ to 150 nm in size. The isolate was sensitive to pH 3, to diethyl ether, and to heat ($50^{\circ}C$ 5 min, $60^{\circ}C$ 1 min). Viral replication was not inhibited by $10^{-4}$ M 5-iododeoxyuridine. Virus infectivity was reduced by anti-HRV (8401-H) rabbit serum, but can not reduced by antisera against infectious hematopoietic necrosis virus (IHNV), chum salmon reovirus (CSV), retrovirus of salmonid (RVS) and infectious pancreatic necrosis virus (IPNV). HRV virus antigen was detected by fluorescent antibody test (FAT) in the cytoplasm of infected EPC cell. Purified isolates virions were composed of: polymerase (L), glycoprotein (G), nucleoprotein (N) and 2 matrix proteins (M1 and M2). Based upon their relative mobilities, the estimated molecular weights of the proteins were: L, 160 kDa; G, 55 kDa; N, 45 kDa; M1, 26 kDa; and M2, 22 kDa.

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RGS3 Suppresses cAMP Response Element (CRE) Activity Mediated by CB2 Cannabinoid Receptor in HEK293 Cells (캐너비노이드 수용체 CB2의 신호전달작용에 미치는 RGS3의 억제적 효과)

  • Kim, Sung-Dae;Lee, Whi-Min;Endale, Mehari;Cho, Jae-Youl;Park, Hwa-Jin;Oh, Jae-Wook;Rhee, Man-Hee
    • Journal of Life Science
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    • v.19 no.11
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    • pp.1506-1513
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    • 2009
  • RGS proteins have been identified as negative regulators of G protein signalling pathways and attenuate the activity of GPCR receptors. However, information on the regulatory effects of RGS proteins in the activity of cannabinoid receptors is limited. In this study, the role of RGS proteins on the signal transduction of the CB2 cannabinoid receptor was investigated in HEK293 cells co-transfected with CB2-receptors and plasmids encoding RGS2, RGS3, RGS4 and RGS5. Treatment of cells with WIN55, 212-2, a CB2 receptor agonist, inhibited forskolin-induced cAMP response element (CRE) activity in CB2-transfected HEK293 (CB2-HEK293) cells. This inhibitory effect of WIN 55, 212-2 on CRE activity was reversed by co-transfection of CB2-HEK293 cells with RGS3, but not with RGS2, RGS4 and RGS5. However, endogenous RGS3 protein knocked down by a small interfering siRNA targeting RGS3 gene enhanced inhibition of forskolin induced CRE activity via agonist induced CB2 receptor signal transduction. These results indicate the functional role of endogenous RGS protein in cannabinoid signaling pathways and define receptor-selective roles of endogenous RGS3 in modulating CRE transcriptional responses to agonist induced CB2 receptor activity.

Effects of Green Tea Extract on the p53 Pathway in the MCF-7 Breast Cancer Cell Line (유방암 세포 주 MCF-7에서의 녹차 추출물이 p53 경로에 미치는 영향)

  • Kwak, Inseok
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1316-1320
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    • 2018
  • The effects of a green tea extract (GTE) were examined using the MCF-7 human breast cancer cell line. Cell viability assays using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that GTE had a significant cytotoxic effect on MCF-7 cells, depending on the concentration of GTE. Western blotting of p53 and its related proteins, p21/cip1 and CDK2, after GTE treatment revealed that a significant and concentration dependent increase in p53 protein in response to GTE. The levels of p21/cip1 proteins were also increased at low GTE concentrations were significantly increased even at the highest GTE concentrations. However, the level of CDK2 was significantly decreased by treatment with high concentrations of GTE. These results indicate that treatment with GTE increased the p53 level in MCF-7 cells, and this activation of p53 markedly elevated the levels of p21/cip1proteins, which, in turn, inhibited CDK2 expression in the MCF-7 cells. The inhibition of CDK2 expression might then affect cell cycle progression. Subsequent FACS analysis indicated that GTE treatment the gradually increased progression of the MCF-7 to the G1 phase. These results clearly demonstrate that the anti-tumor effect of GTE in MCF-7 cells is regulated by p53 arrest of the MCF-7 cells at the G1 stage of cell cycle.

Anti-inflammatory effect of Euonymi Lignum Suberalatum in LPS-activated Raw 264.7 cells and CA-induced paw edema rat model (귀전우(鬼箭羽)의 in vitro 및 in vivo에서의 염증억제효과)

  • Jeon, Chang Kwon;Park, Sang Mi;Park, Chung A;Byun, Sung Hui;Kim, Sang Chan
    • Herbal Formula Science
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    • v.27 no.2
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    • pp.101-120
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    • 2019
  • PURPOSE : Euonymi Lignum Suberalatum (EL) is the stem fin of Euonymi alatus. In traditional Korean medicine, EL is used for treatment of uterine bleeding, metritis and static blood. Recently, many studies have reported several pharmacological effects of EL including anticancer, antimicrobial, antidiabetic activity, and anti-oxidative stress. However, the mechanisms underlying anti-inflammatory effects by the EL is not established. METHODS : To investigate anti-inflammatory effects of Euonymi Lignum Suberalatum Water (ELWE), Raw 264.7 cells were pre-treated with $10-300{\mu}g/mL$ of ELWE, and then exposed to $1{\mu}g/mL$ of LPS. Levels of NO, IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ were detected by ELISA kit. Expression of pro-inflammatory proteins were determined by immunoblot analysis. To evaluate the anti-inflammatory effect in vivo, rat paw edema volume, and expressions of COX-2 and iNOS proteins in carrageenan (CA)-induced rat paw edema model. RESULTS : NO production activated by LPS, was decreased by $30-300{\mu}g/mL$ of ELWE. Production of inflammatory mediators such as $TNF-{\alpha}$, ILs, $PGE_2$ were decreased by ELWE 100 and $300{\mu}g/mL$. In addition, ELWE reduced LPS-mediated iNOS and COX-2 expression. Moreover, ELWE increased $I-{\kappa}B{\alpha}$ expression in cytoplasm and decreased $NF-{\kappa}B$ expression in nucleus. In vivo study, ELWE reduced the increases of paw swelling, and expression of iNOS and COX-2 proteins in paw edema induced by CA injection. CONCLUSION : The results indicate that ELWE could inhibit the acute inflammatory response, via modulation of $NF-{\kappa}B$ activation. Furthermore, inhibition of rat paw edema induced by CA is considered as clear evidence that ELWE may be a useful source to treat acute inflammation.

Studies on the Myofibrillar Proteins Part 2. New Procedure for Extraction of Regulatory Proteins from Myofibrils (근원섬유단백질에 관한 연구 (제2보) 근수축 조절단백질의 새로운 정제방법)

  • Yang, Ryung;Kim, Chul-Jai;Yu, Ju-Hyun;Lee, Hyuk-Sin;Cho, Young-Dong
    • Korean Journal of Food Science and Technology
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    • v.6 no.4
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    • pp.199-208
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    • 1974
  • An attempt was made to study on new method for the extraction of the regulatory proteins from myofibrils, and the procedures for the preparation of desensitized actomyosin and for complete extraction of troponin-tropomyosin complex were developed. When myofibrils were treated through the procedures developed in this study, actomyosin obtained had no Ca-sensitivity, indicating that Ca-sensitizing protein factor had been removed completely from myofibril. Consequently, it was concluded that the procedures developed in this study were convenient to test whether Ca-sensitizing proteins has been removed or not. When Mg-activated ATPase activity of myofibril were measured, the myofibrillar ATPase turned into the actomyosin type ATPase with the progress of the treatment. This result was interpreted to show that the regulatory proteins of the myofibril seems to play a cementing role on the structure of myofibril. When supernatant containing the regulatory proteins were fractionated with $(NH_4)_2SO_4$ saturation solution, regulatory proteins, ${\alpha}-actinin$ and troponia-tropomyosin complex, could be obtained and they showed their typical phyoislogical activity which modify the actin-myosin interaction. The amount of troponin-tropomyosin complex in myofibril was 72 mg per g myofibril. This result was in good agreement with the results reported by many investigators, and therefore it was concluded that our procedures for the extraction of troponin-tropomyosin complex were desirable to study on the quantitative analysis of troponin-tropomyosin complex.

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Expression of the HSV-1 (F) Glycoprotein B Gene in Insect Cells Infected by HcNPV Recombinant

  • Cha, Soung-Chul;Kang, Hyun;Lee, Sook-Yeon;Park, Gap-Ju;Lee, Hyung-Hoan
    • Journal of Microbiology and Biotechnology
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    • v.10 no.3
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    • pp.355-362
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    • 2000
  • The Herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) gene in the pHLA-21 plasmid was inserted into a baculovirus (Hyphantria cunea nuclear polyhedrosis virus) expression vector (lacZ-HcNPV) to construct a recombinant virus gB-HcNPV expressing gB. Spodoptera frugiperda cells infected with this recombinant virus synthesized and processed gB of approximately 120 kDa, which cross-reacted with the monoclonal antibody to gB. The recombinant gB was identified on the membrane of the insect cells using an immunofluorescence assay. Antibodies to this recombinant raised in mice recognize the viral gB and neutralized the infectivity of the HSV-1 in vitro. These results show that the gB gene has the potential to be expressed in insect cells. They also demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the lacZ-HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

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Identification of novel Leishmania major antigens that elicit IgG2a response in resistant and susceptible mice

  • MOHAMMADI Mohammad Reza;ZEINALI Majid;ARDESTANI Sussan K.;KARIMINIA Amina
    • Parasites, Hosts and Diseases
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    • v.44 no.1 s.137
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    • pp.43-48
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    • 2006
  • Experimental murine models with high, intermediate and low levels of genetically based susceptibility to Leishmania major infection reproduce almost entire spectrum of clinical manifestations of the human disease. There are increasing non-comparative studies on immune responses against isolated antigens of L. major in different murine strains. The aim of the present study was to find out whether there is an antigen that can induce protective immune response in resistant and susceptible murine strains. To do that, crude antigenic extract of procyclic and metacyclic promastigotes of L. major was prepared and subjected to SDS-PAGE electrophoresis. Western-blotting was used to search for antigen(s) capable of raising high antibody level of IgG2a versus IgG1 in the sera of both infected resistant and susceptible strains. Two novel antigens from metacyclic promastigotes of L. major (140 and 152 kDa) were potentially able to induce specific dominant IgG2a responses in BALB/c and C57BU6 mice. The 2 antigens also reacted with IgG antibody of cutaneous leishmaniasis patients. We confirm that 140 and 152 kDa proteins of L. major promastigotes are inducing IgG production in mice and humans.

Comparison of the Effects of Retroviral Restriction Factors Involved in Resistance to Porcine Endogenous Retrovirus

  • Bae, Eun Hye;Jung, Yong-Tae
    • Journal of Microbiology and Biotechnology
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    • v.24 no.4
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    • pp.577-583
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    • 2014
  • Three major classes of retroviral restriction factors (APOBEC3G, Tetherin, and TRIM5${\alpha}$) have been identified in mammals. Restriction factors are cellular proteins that are able to limit viral replication by targeting specific steps of the viral life cycle. To evaluate which restriction factor is the most effective to inhibit the replication of porcine endogenous retroviruses (PERVs), the antiviral activity of each restriction factor was compared. In pseudotype assay, the antiviral activity of human tetherin against PERV pseudotype was slightly weaker than that of human APOBEC3G (hA3G). A combination of tetherin and hA3G was more potent than each individual restriction factor. We questioned whether a combination of tetherin and hA3G could also inhibit the spreading replication of PERV. In agreement with the pseudotype assay, two restriction factors inhibit infectious PERV replication in a spreading infection. In this study, hA3G could strongly inhibit the replication of PERV, but tetherin modestly restricted it. Based on these results, we concluded that a combination of tetherin and hA3G is the most effective way to restrict PERV. A combination of different restriction factors will encourage the development of a new approach to treat retroviral disease.