• The Plant Pathology Journal
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• v.19 no.1
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• pp.30-33
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• 2003

The chestnut blight fungus, Cryphonectria parasitica, and its hypovirus aye a useful model system in the study of the mechanisms of hypoviral infection and its consequences, such as a biological control of fungal pathogens. Strains containing the double-stranded (ds) RNA viruses Cryphonectria hypovirus 1 show characteristic symptoms of hypovirulence and display hypovirulence-associated changes, such as reduced pigmentation, sporulation, laccase production, and oxalate accumulation. Interestingly, symptoms caused by hypoviral infection appear to be the result of aberrant expression of a number of specific genes in the hypovirulent strain. Several viral regulated fungal genes are identified as cutinase gene, Lac1, which encodes an extracellular laccase, Crp, which encodes an abundant tissue-specific cell-surface hydrophobin that mediates physical strength, and Mf2/1 and Mf2/2, which encode pheromone genes involved in poor sporulation in the presence of hypo-virus. Since the phenotypic changes in the fungal host are pleiotropic, although coordinated and specific, it has been suggested that the hypovirus disturbs one or several regulatory pathways (Nuss,1996). Accordingly, several studies have shown the implementation of a signal transduction pathway during viral symptom development. Although further studies are required, hypovirulence and its associated symptom development due to the hypoviral regulation of a fungal hetero-trimeric G-protein have been suggested. In addition, recent studies have shown the presence of a novel protein kinase gene cppk1 and its transcriptional upregulation by hypovirus. In this review, the presence of important components in signal transduction pathway, their putative biological function, and viral-specific regulation will be addressed.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.266-275
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• 1990

c-raf protein kinase, a kind of oncogene, is a cytopiasmic serine / threonine-specific protein and is activated by mitogenic or oncogenic signals. The strncture and functions of c-raf protein kinase are considered very similar to those of protein kinase C. Using immunocytochemical approach, the time course of singal transduction of c-raf protein kinase in EC-4 cell was examined with 12-0-tetradecanoylphorbol-13-acetate (TPA) as tumor promotor and plateletderived growth factor (PDGF) as mitogenic factor. Immunoreactive c-raf was initially bound to the perinuclear membrane and then moved into the nucleus. The effect of the long-term treatment with TPA or PDGF was taken place down regulation at different time point. These results indicate that TPA and PDGF give rise to the translocation of c-raf protein kinase through the two different pathways.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.59-73
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• 2008

Several aspects of photoperception and light signal transduction have been elucidated by studies with model plants. However, the information available for economically important crops, such as Fabaceae species, is scarce. In order to incorporate the existing genomic tools into a strategy to advance soybean research, we have investigated publicly available expressed sequence tag (EST) sequence databases in order to identify Glycine max sequences related to genes involved in light-regulated developmental control in model plants. Approximately 38,000 sequences from open-access databases were investigated, and all bona fide and putative photoreceptor gene families were found in soybean sequence databases. We have identified G. max orthologs for several families of transcriptional regulators and cytoplasmic proteins mediating photoreceptor-induced responses, although some important Arabidopsis phytochrome-signaling components are absent. Moreover, soybean and Arabidopsis genefamily homologs appear to have undergone a distinct expansion process in some cases. We propose a working model of light perception, signal transduction and response-eliciting in G. max, based on the identified key components from Arabidopsis. These results demonstrate the power of comparative genomics between model systems and crop species to elucidate several aspects of plant physiology and metabolism.

• The Korean Journal of Pain
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• v.29 no.4
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• pp.239-248
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• 2016

Background: The present study was undertaken to evaluate the incidence of chronic persistent post-surgical pain (CPPP) and the role of signal transduction genes in patients undergoing staging laparotomy for carcinoma ovary. Methods: The present observational study was undertaken following institutional ethical committee approval and informed consent from all the participants. A total 21 patients of ASA grade I to III with age 20-70 years, scheduled for elective staging laparotomy for carcinoma ovary were included. Patients were excluded if had other causes of pain, cognitive dysfunction or chronic neurological disorders. Statistical analysis of pool data was done using SPSS version-17. For various scales like GPE, PDQ, NPSI, the visual analogue scale (VAS), global perceived effect (GPE), the pain DETECT questionnaire (PDQ), and neuropathic pain symptoms inventory (NPSI), one factor repaeted measure ANOVA applied with simple contrast with baseline as on post-operative day 1 (considered as reference and compared with subsequent time-interval), and the P values were adjusted according to "Bonferroni adjustments". In patients with CPPP, the ${\Delta}ct$ values of mRNA expressions of genes at the end of postoperative day 90 were compared with the baseline control values by one factor repeated ANOVA. P value < 0.005 significant. Results: The present study demonstrates 38.1% (8 out of 21 patients) incidence of CPPP. The functional status and quality of life as were observed to be significantly diminished in all patients with chronic pain. An up-regulation in the mRNA expression of signal transduction and a positive correlation was noted between the mRNA expression of signal transduction genes and VAS score in all patients with CPPP at the end of postoperative day 90. Conclusions: The reported incidence of CPPP in patients with carcinoma ovary was 38.1%. An up-regulation and positive correlation between mRNA expression of signal transduction genes and VAS score depicts its potential role in the pathogenesis of CPPP.

• Journal of Life Science
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• v.22 no.3
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• pp.428-436
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• 2012

Protein phosphorylation is a universal mechanism that regulates cellular activities. The brassinosteroid (BR) signal transduction pathway is a relay of phosphorylation and dephosphorylation cascades. It starts with the BR-induced activation of the membrane receptor kinase brassinosteroid insensitive 1 (BRI1), resulting in the dephosphorylation of transcription factors such as BZR1/BES2 and BZR2/BES1 followed by BR-induced gene expression. Brassinosteroid signal transduction research has progressed rapidly by identifying the phosphorylation/dephosphorylation site(s) of the BR-regulated kinase and phosphatase substrates with a simultaneous pursuit of mutant phenotypes. Autophosphorylation, transphosphorylation, and serine/threonine and tyrosine phosphorylation of the receptor protein kinases BRI1 and BRI1-associated kinase (BAK1) have increased the understanding of the regulatory role of those kinases during physiological and developmental processes in plants. The phosphorylation event initiated by BR is also found in the regulation of receptor-mediated endocytosis and the subsequent degradation of the receptor. However, the basic molecular links of the BR signal transduction pathway are not well understood regarding this phosphorylation/dephosphorylation event. This review summarizes the current state of BR signal transduction research to uncover the phosphorylation/dephosphorylation networks and suggests directions for future research on steroid signal transduction to gain a more comprehensive understanding of the process.

• Development and Reproduction
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• v.26 no.1
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• pp.1-12
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• 2022

This study aimed to investigate the signal transduction of phosphorylation sites at the carboxyl (C)-terminal region of equine luteinizing hormone/chorionic gonadotropin receptor (eLH/CGR). The eLH/CGR has a large extracellular domain of glycoprotein hormone receptors within the G protein-coupled receptors. We constructed a mutant (eLH/CGR-t656) of eLH/CGR, in which the C-terminal cytoplasmic tail was truncated at the Phe656 residue, through polymerase chain reaction. The eLH/CGR-t656 removed 14 potential phosphorylation sites in the intracellular C-terminal region. The plasmids were transfected into Chinese hamster ovary (CHO)-K1 and PathHunter Parental cells expressing β-arrestin, and agonist-induced cAMP responsiveness was analyzed. In CHO-K1 cells, those expressing eLH/CGR-t656 were lower than those expressing eLH/CGR wild-type (eLH/CGR-wt). The EC₅₀ of the eLH/CGR-t656 mutant was approximately 72.2% of the expression observed in eLH/CGR-wt. The maximal response in eLH/CGR-t656 also decreased to approximately 43% of that observed in eLH/CGR-wt. However, in PathHunter Parental cells, cAMP activity and maximal response of the eLH/CGR-t656 mutant were approximately 173.5% and 100.8%, respectively, of that of eLH/CGR-wt. These results provide evidence that the signal transduction of C-terminal phosphorylation in eLH/CGR plays a pivotal role in CHO-K1 cells. The cAMP level was recovered in PathHunter Parental cells expressing β-arrestin. We suggest that the signal transduction of the C-terminal region phosphorylation sites is remarkably different depending on the cells expressing β-arrestin in CHO-K1 cells.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.203-205
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• 2002

Light is an environmental signal that regulates photomovement and main energy source of photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). Syn6803 is a popular model system for study of plant functional genomics. In this report, we adopted 2D gel based proteomics study to investigate proteins related with the light absorption and photo-protection in Syn6803. More than 700 proteins were detected on the SDS-gels stained with silver nitrate. Several proteins showing different expression level under various light conditions were identified with MALDI-TOF Mass spectrometry. As a comparison, we also conducted ICAT-based proteome study using WT and cphl (cyanobacterial phytochrome 1) mutant. A cphl deletion led to changes in the expression of proteins involved in translation, photosynthesis including photosystem and CO2 fixation, and cellular regulation. We are currently involved in TAP-tagging method to study protein-protein interactions in search for the molecular component involved in the light signal transduction of Syn6803 photomovement.

• BMB Reports
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• v.47 no.12
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• pp.655-659
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• 2014

Integrin-mediated cell adhesion is important for development, immune responses, hemostasis and wound healing. Integrins also function as signal transducing receptors that can control intracellular pathways that regulate cell survival, proliferation, and cell fate. Conversely, cells can modulate the affinity of integrins for their ligands a process operationally defined as integrin activation. Analysis of activation of integrins has now provided a detailed molecular understanding of this unique form of "inside-out" signal transduction and revealed new paradigms of how transmembrane domains (TMD) can transmit long range allosteric changes in transmembrane proteins. Here, we will review how talin and mediates integrin activation and how the integrin TMD can transmit these inside out signals.

• Journal of Ginseng Research
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• v.21 no.1
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• pp.19-27
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• 1997

The present study was conducted to assess the effect of total saponins from Korean red ginseng on the biosynthesis of inositol phospholipids in vivo and also effects on the metabolic enzymes, such as phosphatidylinositol-specific phospholipase C(Pl-PLC) and PI-kinases. The administration of 0.1% saponin solution, 0.1 ml 3 times a day intraperitoneally to 5 mice for 30 days has increased a 23% of the body weight when it compared with a control group. The amounts of 32P-phoschorus radioactivity incorporated into the phosphoinositides from the liver and brain tissues have increased a 310% and 260%, respectively, in the saponin treated mice. The activities of PI-PLC from liver and brain were stimulated in the various amounts by the conditions treated with saponins. The PI-kinases from liver and brain were also activated by saponins, but its effect was lower than that of PI-PLC. From these results, it was confirmed that red ginseng saponins have affected positively not only on the biosynthesis of phosphoinositides but also on the PI-PLC and PI-kinases related to the cellular signal transduction.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.247-248
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• 2004