• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.83-96
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• 1998

The plant pigment proteins phytochromes are a molecular light sensor or switch for photomorphogenesis involving a variety of growth and developmental responses of plants to red and far-red wavelength light. Underscoring the photomorphogenesis mediated by phytochromes is the light signal transduction at molecular and cellular levels. For example, a number of genes activated by the phytochrome-mediated signal transduction cascade have been identified and characterized, especially in Arabidopsis thaliana. The light sensor/switch function of phytochromes are based on photochromism of the covalently linked tetrapyrrole chromophore between the two photoreversible forms, Pr and Pfr. The photochromism of phytochromes involves photoisomerization of the tetrapyrrole chromophore. The "photosensor" Pr-form ("switch off" conformation) of phytochromes strongly absorbs 660 nm red light, whereas the "switch on" Pfr-conformation preferentially absorbs 730 nm far-red light. The latter is generally considered to be responsible for eliciting transduction cascades of the red light signal for various responses of plants to red light including positive or negative expression of light-responsive genes in plant nuclei and chloroplasts. In this paper, we discuss the structure-function of phytochromes in plant growth and development, with a few examples of biotechnological implications.

• Molecules and Cells
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• 제25권3호
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• pp.397-406
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• 2008

Computational modeling of signal transduction is currently attracting much attention as it can promote the understanding of complex signal transduction mechanisms. Although several mathematical models have been used to examine signaling pathways, little attention has been given to crosstalk mechanisms. In this study, an attempt was made to develop a computational model for the pathways involving growth-factor-mediated mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3'-kinase/protein kinase B (PI3K/Akt). In addition, the dynamics of the protein activities were analyzed based on a set of kinetic data. The simulation approach integrates the information on several levels and predicts systems behavior. The in-silico analysis conducted revealed that the Raf and Akt pathways act independently.

• 한국동물학회지
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• 제37권1호
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• pp.130-136
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• 1994

Although alteration in protein phosphorylation by specific protein kinases is of importance in transducing cellular signals in a variety of neural/endocrine systems, little is known about protein phosphorylation in the hvpothalamus. The present study aims to explore whether activation of the second messenger-dependent protein kinases affects phosphorylation of specific proteins using a cell free phosphorylation system followed by SDS-polvacrylamide gel electrophoresis. Cytoplasmic fractions derived from hvpothalami of immature rats were used as substrates and several activators and/or inhibitors of CAMP-, phosphatidylinositol- and Ca2+-calmodulin-dependent protein kinases were assessed. Many endogenous proteins were extensively phosphorylated and depending on the signal transduction pathways, phosphorvlation profiles were markedly different. The present data indicate that extracellular signals may affect cellular events through protein phosphorylation by second messengers-protein kinases in the rat hypothalamus.

• Tuberculosis and Respiratory Diseases
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• 제43권2호
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• pp.123-127
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• 1996

Secretion of surfactant phospholipid can be stimulated by a variety of agonists acting via at least three different signal transduction mechanisms. These include the adenylate cyclase system with activation of cAMP-dependent protein kinase; activation of protein kinase C either directly or subsequent to activation of phosphoinositide-specific phospholipase C and generation of diacylglycerols and inositol trisphosphate; and a third mechanism that involves incresed $Ca^{2+}$ levels and a calmodulin-dependent step. ATP stimulates secretion via all three mechanisms. The protein kinase C pathway is also coupled to phopholipase D which, acting on relatively abundant cellular phospholipids, generates diacylglycerols that further activate protein kinase C. Sustained protein kinase C activation can maintain phosphatidylcholine secretion for a prolonged period of time. It is likely that interactions between the different signaling pathways have an important role in the overall physiological regulation of surfactant secretion.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.977-980
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• 2014

polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) 유전자가 포함된 재조합 베큘로바이러스를 구축하였다. 본 재조합 베큘로바이러스 시스템은 인간 섬유아세포와 여러 가지 조직에 감염하여 시험하였고 재조합된 유전자의 전달과 유전자 발현을 대조 벡터시스템과 비교하였다. 본 연구의 결과로 제작된 재조합 베큘로바이러스 시스템은 유전자의 전달과 발현에 있어서 대조 벡터시스템 보다 더욱 효과적이고 안전적이었다.

• Genomics & Informatics
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• 제17권1호
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• pp.8.1-8.10
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• 2019

Alveolar type II cells constitute a small fraction of the total lung cell mass. However, they play an important role in many cellular processes including trans-differentiation into type I cells as well as repair of lung injury in response to toxic chemicals and respiratory pathogens. Transcription factors are the regulatory proteins dynamically modulating DNA structure and gene expression. Transcription factor profiling in microarray datasets revealed that several members of AP1, ATF, $NF-{\kappa}B$, and C/EBP families involved in diverse responses were expressed in mouse lung type II cells. A transcriptional factor signature consisting of Cebpa, Srebf1, Stat3, Klf5, and Elf3 was identified in lung type II cells, Sox9+ pluripotent lung stem cells as well as in mouse lung development. Identification of the transcription factor profile in mouse lung type II cells will serve as a useful resource and facilitate the integrated analysis of signal transduction pathways and specific gene targets in a variety of physiological conditions.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.311.1-311.1
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• 2002

Crystal structure of TRAF6 in complex with TRAF6-binding sites from CD40 was previously determined. The structure revealed a distinct TRAF6-binding groove of CD40. the key structural determinant of interaction. The structural information leads to a proposed TRAF6-binding motif. This allows the identification of TRAF6-binding sequences in the hlRAK protein, whose functional requirement in IL-1 mediated signal transduction is further demonstrated using site-directed mutagenesis. The mutational in IL-1 mediated signal transduction is further dimonstrated using site-directed mutagenesis. The mutational effects of hlRAK on the down-stream NF-${\kappa}$ signaling shows the importance of the TRAF6 interface for signaling by IL-1.

• BMB Reports
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• 제44권10호
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• pp.647-652
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• 2011

The protein transduction domains have been reported to have potential to deliver the exogenous molecules, including proteins, to living cells. However, poor transduction of proteins limits therapeutic application. In this study, we examined whether imipramine could stimulate the transduction efficiency of PEP-1 fused proteins into astrocytes. PEP-1-catalase (PEP-1-CAT) was transduced into astrocytes in a time- and dose-dependent manner, reducing cellular toxicity induced by $H_2O_2$. Additionally, the group of PEP-1-CAT + imipramine showed enhancement of transduction efficiency and therefore increased cellular viability than that of PEP-1-CAT alone. In the gerbil ischemia models, PEP-1-CAT displayed significant neuroprotection in the CA1 region of the hippocampus. Interestingly, PEP-1-CAT + imipramine prevented neuronal cell death and lipid peroxidation more markedly than PEP-1-CAT alone. Therefore, our results suggest that imipramine can be used as a drug to enhance the transduction of PEP-1 fusion proteins to cells or animals and their efficacies against various disorders.

• BMB Reports
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• 제44권5호
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• pp.329-334
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• 2011

Many proteins with poor transduction efficiency were reported to be delivered to cells by fusion with protein transduction domains (PTDs). In this study, we investigated the effect of levosulpiride on the transduction of PEP-1 ribosomal protein S3 (PEP-1-rpS3), and examined its influence on the stimulation of the therapeutic properties of PEP-1-rpS3. PEP-1-rpS3 transduction into HaCaT human keratinocytes and mouse skin was stimulated by levosulpiride in a manner that did not directly affect the cell viability. Following 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice, levosulpiride alone was ineffective in reducing TPA-induced edema and in inhibiting the elevated productions of inflammatory mediators and cytokines, such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1${\beta}$, and tumor necrosis factor-${\alpha}$. Anti-inflammatory activity by PEP-1-rpS3 + levosulpiride was significantly more potent than by PEP-1-rpS3 alone. These results suggest that levosulpiride may be useful for enhancing the therapeutic effect of PEP-1-rpS3 against various inflammatory diseases.

• Molecules and Cells
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• 제19권1호
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• pp.137-142
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• 2005

We showed recently that ginsenosides inhibit the activity of various types of ion channel. Here we have investigated the role of the carbohydrate component of ginsenoside $Rg_3$ in the inhibition of $Na^+$ channels. The channels were expressed in Xenopus oocytes by injecting cRNAs encoding rat brain Nav1.2 ${\alpha}$ and ${\beta}1$ subunits, and analyzed by the two-electrode voltage clamp technique. Treatment with $Rg_3$ reversibly inhibited the inward $Na^+$ peak current ($I_{Na}$) with an $IC_{50}$ of $32.2{\pm}4.5{\mu}M$, and the inhibition was voltage-dependent. To examine the role of the sugar moiety, we prepared a straight chain form of the second glucose and a conjugate of this glucose with 3-(4-hydroxyphenyl) propionic acid hydrazide (HPPH). Neither derivative inhibited $I_{Na}$. Treatment with the carbohydrate portion of ginsenoside $Rg_3$, sophorose [${\beta}-D-glucopyranosyl$ ($1{\rightarrow}2$)-${\beta}-glucopyranoside$], or the aglycone (protopanaxadiol), on their own or in combination had no effect on $I_{Na}$. These observations indicate that the carbohydrate portion of ginsenoside $Rg_3$ plays an important role in its effect on the $Na^+$ channel.