• Development and Reproduction
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• v.18 no.1
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• pp.65-71
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• 2014

Cell cycle process is regulated by a number of protein kinases and among them, serine/threonine kinases carry phosphate group from ATP to substrates. The most important three kinase families are Cyclin-dependent kinase (Cdk), Polo-like kinase (Plk), and Aurora kinase. Polo-like kinase family consists of 5 members (Plk1-Plk5) and they are involved in multiple functions in eukaryotic cell division. It regulates a variety of aspects such as, centrosome maturation, checkpoint recovery, spindle assembly, cytokinesis, apoptosis and many other features. Recently, it has been reported that Plks are related to tumor development and over-expressed in many kinds of tumor cells. When injected the anti-Plk antibody into human cells, the cells show aneuploidy, and if inhibit Plks, most of the mitotic cell division does not proceed properly. For that reasons, many inhibitors of Plk have been recently emerged as new target for remedy of the cancer therapeutic research. In this paper, we reviewed briefly the characteristics of Plk families and how Plks work in regulating cell cycles and cancer formation, and the possibilities of Plks as target for cancer therapy.

• Molecules and Cells
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• v.26 no.1
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• pp.100-105
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• 2008

Glycogen synthase kinase $3{\beta}$ (GSK $3{\beta}$) is a serine/threonine kinase that phosphorylates substrates such as ${\beta}$-catenin and is involved in a variety of biological processes, including embryonic development, metabolism, tumorigenesis, and cell death. Here, we present evidence that human GSK $3{\beta}$ is associated with Fe65, which has the characteristics of an adaptor protein, possessing a WW domain, and two phosphotyrosine interaction domains, PID1 and PID2. The GSK $3{\beta}$ catalytic domain also contains a putative WW domain binding motif ($^{371}PPLA^{374}$), and we observed, using a pull down approach and co-immunoprecipitation, that it interacts physically with Fe65 via this motif. In addition, we detected co-localization of GSK $3{\beta}$ and Fe65 by confocal microscopy, and this co-localization was disrupted by mutation of the putative WW domain binding motif of GSK $3{\beta}$. Finally, in transient transfection assays interaction of GSK $3{\beta}$ (wt) with Fe65 induced substantial cell apoptosis, whereas interaction with the GSK $3{\beta}$ AALA mutant ($^{371}AALA^{374}$) did not, and we noted that phosphorylation of the Tyr 216 residue of the GSK $3{\beta}$ AALA mutant was significantly reduced compared to that of GSK $3{\beta}$ wild type. Thus, our observations indicate that GSK $3{\beta}$ binds to Fe65 through its $^{371}PPLA^{374}$ motif and that this interaction regulates apoptosis and phosphorylation of Tyr 216 of GSK $3{\beta}$.

• BMB Reports
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• v.39 no.5
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• pp.607-617
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• 2006

A novel calcium-dependent protein kinase gene (designated as IiCPK2) was cloned from tetraploid Isatis indigotica. The full-length cDNA of IiCPK2 was 2585 bp long with an open reading frame (ORF) of 1878 bp encoding a polypeptide of 625 amino acid residues. The predicted IiCPK2 polypeptide included three domains: a kinase domain, a junction domain (or autoinhibitory region), and a C-terminal calmodulin-like domain (or calcium-binding domain), which presented a typical structure of plant CDPKs. Further analysis of IiCPK2 genomic DNA revealed that it contained 7 exons, 6 introns and the length of most exons was highly conserved. Semi-quantitative RT-PCR revealed that the expression of IiCPK2 in root, stem and leaf were much higher in tetraploid sample than that in diploid progenitor. Further expression analysis revealed that gibberellin ($GA_3$), NaCl and cold treatments could up-regulate the IiCPK2 transcription. All our findings suggest that IiCPK2 might participate in the cold, high salinity and GA3 responsive pathways.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.43-43
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• 2014

The rice blast disease caused by of Magnaporthe oryzae is one of the most destructive diseases of rice. By the microarray analysis, we profiled expression changes of genes during conidiation and found out many putative genes that are up-regulated. Among those, we first selected MGG_06399 encoding a dual-specificity tyrosine-regulated protein kinase (DYRK), homologous to YAK1 in yeast. To investigate functional roles of MoYAK1, We made ${\Delta}Moyak1$ mutants by homology dependent gene replacement. The deletion mutant showed a remarkable reduction in conidiation and produced abnormally shaped conidia smaller than those of wild type. The conidia form ${\Delta}Moyak1$ were able to develop a germ tube, but failed to form apppressoria on a hydrophobic coverslip. The ${\Delta}Moyak1$ formed appressria on a hydrophobic cover slip when exogenous cAMP was induced, but the appressoria shape was abnormal. The ${\Delta}Moyak1$ also formed appressoria abberent in shape on onion epidermis and rice sheaths and failed to penetrate the surface of the plants. These data indicate that MoYAK1 is associated with cAMP/PKA pathway and important for conidiation, appressorial formation and pathogenic development in Magnaporthe oryzae. Detailed characterization of MoYAK1 will be presented.

• Journal of Life Science
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• v.22 no.1
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• pp.87-91
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• 2012

Phorbol 12-myristate 13-acetate (PMA), a known tumor-promoting phorbol ester, activates the signal transduction enzyme protein kinase C (PKC) in animal cells. We investigated the effect of PMA on the regulation of gravitropism via ethylene production in primary roots of maize. PMA stimulated root growth and the gravitropic response in a concentration-dependent manner at $10^{-6}$ M and $10^{-4}$ M over 8 hrs. These effects were prevented by treatment with staurosporine (STA), a potent inhibitor of PKC. These results support the possibility that the gravitropic response might be regulated through protein kinases that are involved in the signal transduction system. Ethylene is known to play a role in the regulation of root growth and gravitropism. Ethylene production was increased by about 26% and 37% of the control rate in response to $10^{-6}$ M and $10^{-4}$ M PMA, respectively. PMA also stimulated the activity of ACC synthase (ACS), which converts the S-adenosyl-L-methionine (AdoMet) to 1-aminocyclopropane-1-carboxylic acid (ACC) in the ethylene production pathway. These effects on ethylene production were also prevented by STA treatment. These results suggest that the root gravitropic response in maize is regulated through protein kinases via ethylene production.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.105-110
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• 2004

Akt (or Protein Kinase B; PKB) is a serine/threonine kinase and is activated by phosphoinositide 3-kinase (PI3K) pathway. Recent evidence indicates that the abnormal activities or expression of Akt is closely associated with cancer, diabetes and neuro-degenerative diseases. These findings mean that Akt is likely to be a new therapeutic target for the treatment of disease. Here, we screened the effects of dithiolo-dithione derivatives such as SWU-20004, SWU-20009 and SWU-20025 on Akt activities. Among these compounds, only SWU-20009 (2-Thioxo-[1,3]dithiolo[4,5- $\beta$][1,4]dithiine-5,6-dicarboxylic acid dimethyl ester) inhibited the growth of KATOIII cell at micromolar range of concentration. Further investigation also revealed that SWU-20009 inhibited cellular Akt activity and induced apoptotic cell death.

• 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.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.105-115
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• 2015

Background: Alcoholic steatosis is the earliest and most common liver disease, and may precede the onset of more severe forms of liver injury. Methods: The effect of Korean Red Ginseng extract (RGE) was tested in two murine models of ethanol (EtOH)-feeding and EtOH-treated hepatocytes. Results: Blood biochemistry analysis demonstrated that RGE treatment improved liver function. Histopathology and measurement of hepatic triglyceride content verified the ability of RGE to inhibit fat accumulation. Consistent with this, RGE administration downregulated hepatic lipogenic gene induction and restored hepatic lipolytic gene repression by EtOH. The role of oxidative stress in the pathogenesis of alcoholic liver diseases is well established. Treatment with RGE attenuated EtOH-induced cytochrome P450 2E1, 4-hydroxynonenal, and nitrotyrosine levels. Alcohol consumption also decreased phosphorylation of adenosine monophosphate-activated protein kinase, which was restored by RGE. Moreover, RGE markedly inhibited fat accumulation in EtOH-treated hepatocytes, which correlated with a decrease in sterol regulatory element-binding protein-1 and a commensurate increase in sirtuin 1 and peroxisome proliferator-activated receptor-a expression. Interestingly, the ginsenosides Rb2 and Rd, but not Rb1, significantly inhibited fat accumulation in hepatocytes. Conclusion: These results demonstrate that RGE and its ginsenoside components inhibit alcoholic steatosis and liver injury by adenosine monophosphate-activated protein kinase/sirtuin 1 activation both in vivo and in vitro, suggesting that RGE may have a potential to treat alcoholic liver disease.

• BMB Reports
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• v.44 no.7
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• pp.490-495
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• 2011

Transcription factor AP-$2{\alpha}$ involves in the process of mammalian embryonic development and tumorigenesis. Many studies have shown that AP-$2{\alpha}$ functions in association with other interacting proteins. In a two-hybrid screening, the regulatory subunit ${\beta}$ of protein casein kinase 2 ($CK2{\beta}$) was identified as an interacting protein of AP-$2{\alpha}$; we confirmed this interaction using in-vitro GST pull-down and in-vivo co-immunoprecipitation assays; in an endogenous co-immunoprecipitation experiment, we further found the catalytic subunit ${\alpha}$ of protein casein kinase 2 ($CK2{\alpha}$) also exists in the complex. Phosphorylation analysis revealed that AP-$2{\alpha}$ was phosphorylated by CK2 kinase majorly at the site of Ser429, and such phosphorylation could be blocked by CK2 specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) in a dose-dependent manner. Luciferase assays demonstrated that both $CK2{\alpha}$ and $CK2{\beta}$ enhanced the transcription activity of AP-$2{\alpha}$; moreover, $CK2{\beta}$ increased the stability of AP-$2{\alpha}$. Our data suggest a novel cellular function of CK-2 as a transcriptional co-activator of AP-$2{\alpha}$.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.236-243
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• 2023

Platelets act a fundamental role in primary- and secondary-hemostasis, however, platelet activation may cause thrombosis simultaneously. Therefore, control of platelet aggregation is crucial in preventing thrombosis-mediated diseases. Recently, the development of insect materials is attracting attention. Among the highly nutritious functional food sources, insects such as two-spotted cricket (Gryllus bimaculatus). Gryllus bimaculatus (G. bimaculatus) contains high protein and unsaturated fatty acids and has been registered as a food material September 2015 by the Ministry of Food and Drug Safety of Korea. In this study, we examined whether G. bimaculatus extract (GBE) inhibits platelet aggregation, intracellular calcium mobilization, thromboxane A₂ production and glycoprotein IIb/IIIa (integrin αIIb/β3) activation. We investigated whether GBE can regulate signaling molecules, such as 1, 4, 5-triphosphate receptor type I, extracellular signal-regulated kinase, cytosolic phospholipase A₂, mitogen-activated protein kinases p38, vasodilator-stimulated phosphoprotein, phosphatidylinositol-3 kinase, Akt, glycogen synthase kinase-3α/β, and SYK. Taken together, GBE is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.