• Title/Summary/Keyword: G proteins

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Inconsistency in the Improvements of Gel Strength in Chicken and Pork Sausages Induced by Microbial Transglutaminase

  • Kawahara, S.;Ahhmed, A.M.;Ohta, K.;Nakade, K.;Muguruma, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.8
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    • pp.1285-1291
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    • 2007
  • This research investigated variation in the improvement of the texture of chicken and pork sausages induced by microbial transglutaminase (MTG). The extractability of myofibrillar proteins from these sausages as well as the ${\varepsilon}-({\gamma}-glutamyl)$lysine (G-L) content were also investigated. MTG treatment of sausages significantly increased the breaking strength values in both meat types, especially for samples incubated at $40^{\circ}C$. However, values of the breaking strength in both meat types were increased differently. The variation in protein extractability of samples incubated at $40^{\circ}C$ for both meat types could lead to some consideration of the mechanisms and the high accessions of myosin heavy chain (MHC) to MTG. SDS-PAGE analysis showed significant changes in the density of the bands after adding MTG, especially for the pork samples in which the bands disappeared totally. The G-L content in the presence of MTG was double that in control samples of both meat types. This study suggests that the binding ability of myofibrillar proteins with MTG is strong. This leads us to suggest that MTG functions positively with different improvements in the texture of chicken and pork products that are treated mechanically, such as sausages. Variability in gel improvement level between chicken and pork sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine content.

Identification of interacting proteins of retinoid-related orphan nuclear receptor gamma in HepG2 cells

  • Huang, Ze-Min;Wu, Jun;Jia, Zheng-Cai;Tian, Yi;Tang, Jun;Tang, Yan;Wang, Ying;Wu, Yu-Zhang;Ni, Bing
    • BMB Reports
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    • v.45 no.6
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    • pp.331-336
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    • 2012
  • The retinoid-related orphan nuclear receptor gamma ($ROR{\gamma}$) plays critical roles in regulation of development, immunity and metabolism. As transcription factor usually forms a protein complex to function, thus capturing and dissecting of the $ROR{\gamma}$ protein complex will be helpful for exploring the mechanisms underlying those functions. After construction of the recombinant tandem affinity purification (TAP) plasmid, pMSCVpuro $ROR{\gamma}$-CTAP(SG), the nuclear localization of $ROR{\gamma}$-CTAP(SG) fusion protein was verified. Following isolation of $ROR{\gamma}$ protein complex by TAP strategy, seven candidate interacting proteins were identified. Finally, the heat shock protein 90 (HSP90) and receptor-interacting protein 140 (RIP140) were confirmed to interplay with $ROR{\gamma}$ by co-immunoprecipitation. Interference of HSP90 or/and RIP140 genes resulted in dramatically decreased expression of CYP2C8 gene, the $ROR{\gamma}$ target gene. Data from this study demonstrate that HSP90 and RIP140 proteins interact with $ROR{\gamma}$ protein in a complex format and function as co-activators in the $ROR{\gamma}$-mediated regulatory processes of HepG2 cells.

Analysis of Essential Proteins in Protein-Protein Interaction Networks (단백질 상호작용 네트워크에서 필수 단백질의 견고성 분석)

  • Ryu, Jae-Woon;Kang, Tae-Ho;Yoo, Jae-Soo;Kim, Hak-Yong
    • The Journal of the Korea Contents Association
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    • v.8 no.6
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    • pp.74-81
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    • 2008
  • Protein interaction network contains a small number of highly connected protein, denoted hub and many destitutely connected proteins. Recently, several studies described that a hub protein is more likely to be essential than a non-hub protein. This phenomenon called as a centrality-lethality rule. This nile is widely credited to exhibit the importance of hub proteins in the complex network and the significance of network architecture as well. To confirm whether the rule is accurate, we Investigated all protein interaction DBs of yeast in the public sites such as Uetz, Ito, MIPS, DIP, SGB, and BioGRID. Interestingly, the protein network shows that the rule is correct in lower scale DBs (e.g., Uetz, Ito, and DIP) but is not correct in higher scale DBs (e.g., SGD and BioGRID). We are now analyzing the features of networks obtained from the SGD and BioGRD and comparing those of network from the DIP.

Mucosal Immune Response and Adjuvant Activity of Genetically Fused Escherichia coli Heat-Labile Toxin B Subunit

  • Lee, Yung-Gi;Kang, Hyung-Sik;Lee, Cheong-Ho;Paik, Sang-Gi
    • Journal of Microbiology and Biotechnology
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    • v.14 no.3
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    • pp.490-497
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    • 2004
  • Although the E. coli heat-labile enterotoxin B subunit (LTB) is known to be a potent mucosal adjuvant towards co-administrated unrelated antigens and immunoregulator in T-helper 1-type-mediated autoimmune diseases, a more efficient and useful LTB is still required for prospective vaccine adjuvants. To determine whether a novel chimeric LTB subunit would produce an enhanced mucosal adjuvant activity and immune response, a number of LTB subunits were genetically fused with chimeric proteins using the epitope genes of the envelope glycoprotein E2 (gp51-54) from the classical swine fever virus (CSFV). It was found that the total serum immunoglobulin (Ig) levels of BALB/c mice orally immunized with chimeric proteins containing an N-terminal linked LTB subunit (LE1, LE2, and LE3) were higher than those of mice immunized with LTB, E2 epitope, and chimeric proteins that contained a C-terminal linked LTB subunit. In particular, immunization with LE1 markedly increased both the total serum Ig and fecal IgA level compared to immunization with LTB or the E2 epitope. Accordingly, the current results demonstrated that the LTB subunit in a chimeric protein exhibited a strong mucosal adjuvant effect as a carrier molecule, while the chimeric protein containing the LTB subunit stimulated the mucosal immune system by mediating the induction of antigen-specific serum Ig and mucosal IgA. Consequently, an LE1-mediated mucosal response may contribute to the development of effective antidiarrhea vaccine adjuvants.

Mechanism Underlying NaF-Induced Apoptosis in Human Oral Squamous Cell Carcinoma

  • Hur, Young-Joo;Kim, Do-Kyun;Lee, Seung-Eun;Kim, In-Ryoung;Jeong, Na-Young;Kim, Ji-Young;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.35 no.2
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    • pp.51-60
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    • 2010
  • Few studies have evaluated the apoptosis-inducing efficacy of NaF on cancer cells in vitro but there has been no previous investigation of the apoptotic effects of NaF on human oral squamous cell carcinoma cells. In this study, we have investigated the mechanisms underlying the apoptotic response to NaF treatment in the YD9 human squamous cell carcinoma cell line. The viability of YD9 cells and their growth inhibition were assessed by MTT and clonogenic assays, respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to detect apoptosis. YD9 cells were treated with NaF, and western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, and MMP and proteasome activity assays were performed sequentially. The NaF treatment resulted in a time- and dose-dependent decrease in YD9 cell viability, a dose-dependent inhibition of cell growth, and the induction of apoptotic cell death. The apoptotic response of these cells was manifested by nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, a significant shift of the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF treatment resulted in the downregulation of G1 cell cyclerelated proteins, and upregulation of p53 and the Cdk inhibitor $p27^{KIP1}$. Taken collectively, our present findings demonstrate that NaF strongly inhibits YD9 cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via mitochondrial and caspase pathways.

Mechanism Underlying Curcumin-induced Apoptosis and Cell Cycle Arrest on SCC25 Human Tongue Squamous Cell Carcinoma Cell Line

  • Moon, Jung-Bon;Lee, Kee-Hyun;Kim, In-Ryoung;Kim, Gyoo-Cheon;Kwak, Hyun-Ho;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.39 no.1
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    • pp.23-33
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    • 2014
  • Several studies have shown that curcumin, which is derived from the rhizomes of turmeric, possesses antimicrobial, antioxidant and anti-inflammatory properties. The antitumor properties of curcumin have also now been demonstrated more recently in different cancers. This study was undertaken to investigate the modulation of cell cycle-related proteins and the mechanisms underlying apoptosis induction by curcumin in the SCC25 human tongue squamous cell carcinoma cell line. Curcumin treatment of the SCC25 cells resulted in a time- and dose-dependent reduction in cell viability and cell growth, and onset of apoptotic cell death. The curcumin-treated SCC25 cells showed several types of apoptotic manifestations, such as nuclear condensation, DNA fragmentation, reduced MMP and proteasome activity, and a decreased DNA content. In addition, the treated SCC25 cells showed a release of cytochrome c into the cytosol, translocation of AIF and DFF40/CAD into the nuclei, a significant shift in the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-7, caspase-6, caspase-3, PARP, lamin A/C, and DFF45/ICAD. Furthermore, curcumin exposure resulted in a downregulation of G1 cell cycle-related proteins and upregulation of $p27^{KIP1}$. Taken together, our findings demonstrate that curcumin strongly inhibits cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via proteasomal, mitochondrial, and caspase cascades in SCC25 cells.

Comparative Interactomes of VRK1 and VRK3 with Their Distinct Roles in the Cell Cycle of Liver Cancer

  • Lee, Namgyu;Kim, Dae-Kyum;Han, Seung Hyun;Ryu, Hye Guk;Park, Sung Jin;Kim, Kyong-Tai;Choi, Kwan Yong
    • Molecules and Cells
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    • v.40 no.9
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    • pp.621-631
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    • 2017
  • Vaccinia-related kinase 1 (VRK1) and VRK3 are members of the VRK family of serine/threonine kinases and are principally localized in the nucleus. Despite the crucial roles of VRK1/VRK3 in physiology and disease, the molecular and functional interactions of VRK1/VRK3 are poorly understood. Here, we identified over 200 unreported VRK1/VRK3-interacting candidate proteins by affinity purification and LC-MS/MS. The networks of VRK1 and VRK3 interactomes were found to be associated with important biological processes such as the cell cycle, DNA repair, chromatin assembly, and RNA processing. Interactions of interacting proteins with VRK1/VRK3 were confirmed by biochemical assays. We also found that phosphorylations of XRCC5 were regulated by both VRK1/VRK3, and that of CCNB1 was regulated by VRK3. In liver cancer cells and tissues, VRK1/VRK3 were highly upregulated and its depletion affected cell cycle progression in the different phases. VRK3 seemed to affect S phase progression and G2 or M phase entry and exit, whereas VRK1 affects G1/S transition in the liver cancer, which could be explained by different interacting candidate proteins. Thus, this study not only provides a resource for investigating the unidentified functions of VRK1/VRK3, but also an insight into the regulatory roles of VRK1/VRK3 in biological processes.

Comparative Proteomic Analysis of Changes in the Bovine Whey Proteome during the Transition from Colostrum to Milk

  • Zhang, Le-Ying;Wang, Jia-Qi;Yang, Yong-Xin;Bu, Deng-Pan;Li, Shan-Shan;Zhou, Ling-Yun
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.2
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    • pp.272-278
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    • 2011
  • Bovine whey protein expression patterns of colostrum are much different from that of milk. Moreover, bovine colostrum is an important source of protective, nutritional and developmental factors for the newborn. However, to our knowledge, no research has been performed to date using a comparative proteomic method on the changes in the bovine whey proteome during the transition from colostrum to milk. This study therefore separated whey protein of days 1, 3, 7 and 21 after calving using two dimension electrophoresis. Differentially expressed proteins at different collection times were identified using high-performance liquid chromatography in tandem with mass spectrometry (LC/MS) and validated by enzyme-linked immunosorbent assay (ELISA) in order to understand the developmental changes in the bovine whey proteome during the transition from colostrum to milk. The expression patterns of whey protein of days 1 and 3 post-partum were similar except that immunoglobulin G was down-regulated on day 3, and four proteins were found to be down-regulated on days 7 and 21 compared with day 1 after delivering, including immunoglobulin G, immunoglobulin M, albumin, and lactotransferrin, which are involved in immunity and molecule transport. The results of this study confirm the comparative proteomic method has the advantage over other methods such as ELISA and immunoassays in that it can simultaneously detect more differentially expressed proteins. In addition, the difference in composition of milk indicates a need for adjustment of the colostrum feeding regimen to ensure a protective immunological status for newborn calves.

Pemetrexed Induces G1 Phase Arrest and Apoptosis through Inhibiting Akt Activation in Human Non Small Lung Cancer Cell Line A549

  • Wu, Dong-Ming;Zhang, Peng;Xu, Guang-Chao;Tong, Ai-Ping;Zhou, Cong;Lang, Jin-Yi;Wang, Chun-Ting
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1507-1513
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    • 2015
  • Pemetrexed is an antifolate agent which has been used for treating malignant pleural mesothelioma and non small lung cancer in the clinic as a chemotherapeutic agent. In this study, pemetrexed inhibited cell growth and induced G1 phase arrest in the A549 cell line. To explore the molecular mechanisms of pemetrexed involved in cell growth, we used a two-dimensional polyacrylamide gel electrophoresis (2-DE) proteomics approach to analyze proteins changed in A549 cells treated with pemetrexed. As a result, twenty differentially expressed proteins were identified by ESI-Q-TOF MS/MS analysis in A549 cells incubated with pemetrexed compared with non-treated A549 cells. Three key proteins (GAPDH, HSPB1 and EIF4E) changed in pemetrexed treated A549 cells were validated by Western blotting. Accumulation of GAPDH and decrease of HSPB1 and EIF4E which induce apoptosis through inhibiting phosphorylation of Akt were noted. Expression of p-Akt in A549 cells treated with pemetrexed was reduced. Thus, pemetrexed induced apoptosis in A549 cells through inhibiting the Akt pathway.

Cytopathic Effects of Japanese Encephalitis Virus Structural Proteins in BHK-21 Cells (BHK-21 세포에서의 일본뇌염바이러스 구조단백질에 의한 세포독성)

  • 성기민;정용석
    • Korean Journal of Microbiology
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    • v.38 no.3
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    • pp.213-220
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    • 2002
  • Inducible expression system for the three structural proteins, capsid (C), precursor membrane (prM/M), and envelop (E) of Japanese encephalitis virus (JEV) was established in BHK-21 cells. Doxycycline, a tetracycline analog, was utilized as an inducer. Transfectants BHK-21/IV (vector only), BHK-21/IC (for C), BHK-21/IP3 (for prM), and BHK-21/IE1 (for E) were selected and cloned in the presence of G4l8 or hygromycin. Transcribed mRNAs for the corresponding genes were observed after doxycycline induction. Effects by the JEV structural gene expression on the transfectants were monitored via cell growth, chromatin condensation, internucleosomal DNA fragmentation, and DNA contents analyses. Clear cell growth retardation and chromatin condensation were observed in all three transfectants while only BHK-2/IC corresponded to the induction status in the DNA fragmentation and DNA content analyses. Combined results, therefore, suggested that JEV capsid protein should be one of the direct and independent factors in apoptotic cell death induced by IEV infection.