• Molecules and Cells
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• 제42권9호
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• pp.646-660
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• 2019

Abscisic acid (ABA) is a phytohormone essential for seed development and seedling growth under unfavorable environmental conditions. The signaling pathway leading to ABA response has been established, but relatively little is known about the functional regulation of the constituent signaling components. Here, we present several lines of evidence that Arabidopsis Raf-like kinase Raf10 modulates the core ABA signaling downstream of signal perception step. In particular, Raf10 phosphorylates subclass III SnRK2s (SnRK2.2, SnRK2.3, and SnRK2.6), which are key positive regulators, and our study focused on SnRK2.3 indicates that Raf10 enhances its kinase activity and may facilitate its release from negative regulators. Raf10 also phosphorylates transcription factors (ABI5, ABF2, and ABI3) critical for ABA-regulted gene expression. Furthermore, Raf10 was found to be essential for the in vivo functions of SnRK2s and ABI5. Collectively, our data demonstrate that Raf10 is a novel regulatory component of core ABA signaling.

• Clinical and Experimental Reproductive Medicine
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• 제32권3호
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• pp.207-216
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• 2005

Objective: To understand the crucial requirement for the normal early folliculogenesis, we evaluated molecular as well as physiological differences during in vitro ovarian culture. Among the important regulators for follicle development, anti-Müllerian hormone (AMH) and FSH Receptor (FSHR) have been known to be expressed in the cuboidal granulosa cells. Meanwhile, it is known that c-kit is germ cell-specific and GDF-9 is also oocyte-specific regulator. To evaluate the functional requirement for the competence of normal follicular development, we investigated the differential mRNA expression of several factors secreted from granulosa cells and oocytes between in vivo and in vitro developed ovaries. Materials and Methods: Ovaries from ICR neonates (the day of birth) were cultured for 4 days (for primordial to primary transition) or 8 days (for secondary follicle formation) in ${\alpha}$-MEM glutamax supplemented with 3 mg/ml BSA without serum or growth factors. The mRNA levels of the several factors were investigated by quantitative real-time PCR analysis. Freshly isolated 0-, 4-, and 8-day-old ovaries were used as control. Results: The mRNA of AMH and FSHR as granulosa cell factors was highly increased according to the ovarian development in both of 4- and 8-day-old control. However, the mRNA expression was not induced in both of 4- and 8-day in vitro cultured ovaries. The mRNA expression of GDF-9 known to regulate follicle growth as an oocyte factor was different between in vivo and in vitro developed ovaries. In addition, the transcript of GDF-9 was expressed in the primordial follicles of mouse ovaries. The mRNA expression of c-kit was not significantly different during the early folliculogenesis in vitro. Conclusion: This is the first report regarding endogenous AMH and FSHR expression during the early folliculogenesis in vitro. In conclusion, it will be very valuable to evaluate cuboidal granulosa cell factors as functional marker(s) for normal early folliculogenesis in vitro.

• 한국발생생물학회지:발생과생식
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• 제3권1호
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• pp.69-74
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• 1999

인슐린 유사 성장 호르몬 1과 2 (IGF-1 & IGF-2)는 착상 전 초기배아 발생을 조절하는 중요한 요소이다. 생쥐 착상 전 초기배아에서 IGF-1의 역할에 관한 연구를 위해, IGF-1과 IGF-1 수용체의 전사물의 존재 여부를 난자와 착상 전 초기배아에서 조사하였다. 새로이 고안된 IGF-1 primer를 이용하여 난자에서 전사물을 검출하였다. 그리고, PCR 산물을 제한효소인 Msp I으로 절단하여 확인하였다. 이 실험에서 IGF-1과 IGF-1 수용체의 전사물이 난자와 착상 전 초기배아에서 모두 검출됨을 보였다. GV-난자에 다량 존재하는 mRNA는 4- 혹은 8-세포기까지 지속적으로 감소하다가 이후에 다시 증가하는 양상을 보였다. GV-난자에서 IGF-1과 IGF-lR 전사물이 존재한다는 것은 초기배아에 존재하는 전사물이 모계유래 산물임을 암시한다. 또한, 난자와 착상 전 초기배아에 IGF-1과 IGF-1 수용체 전사물이 존재하는 것으로 보아 착상 전 초기배아에서 IGF-1은 자가 분비되어 IGF-1 수용체의 신호전달 경로를 통하여 배아발생에 작용하는 것으로 사료된다.

• Journal of Korea Trade
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• 제27권2호
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• pp.47-60
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• 2023

Purpose - This paper assesses the trade potential and efficiency of Korea and China in the aquatic products trade. Trade efficiency and potential are the main factors that affect the growth of a country's trade. In this study, a time-varying stochastic frontier trade gravity model was constructed to analyze the trade potential and efficiency between Korea and China. By integrating the results of trade theory and empirical analysis, measures and suggestions were proposed to encourage the release of trade potential of fish exports between Korea and China. Design/methodology - In this paper, GDP per capita instead of economic size was chosen as an explanatory variable, and population size and relative distance were selected as explanatory variables to measure trade potential. For trade non-efficiency terms, regional organizations, political factors, and economic factors were mainly considered, and variables such as free trade agreements, political stability, regulatory quality, government efficiency, currency freedom, investment freedom, financial freedom, and trade freedom were selected. Panel data for South Korea and 14 aquatic products trading partners (including China) from 2002 to 2020 were used in the empirical analysis. Findings - In the past 19 years, South Korea's export trade potential of aquatic products to China has never been lower than 70%. It was above 90% from 2006 to 2018, and has been at a high level for a long time. This shows that China's aquatic product market has large potential for development. Originality/value - This study examines the effectiveness and potential of South Korea's exports of aquatic items to China in a methodical and comprehensive empirical manner. The evaluation of the export trade potential of South Korea's aquatic goods to China is more precise when the effects of regional organization, political, and economic variables are taken into account in the trade non-efficiency term of the stochastic frontier gravity model. At the same time, we propose to increase the scale of South Korea's aquatic products trade from the perspective of China's demand. This issue of trade studies is underexplored both empirically and in theory, although the issue has long been important to Korean and world trade.

• BMB Reports
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• 제38권4호
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• pp.500-506
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• 2005

HOX11 encodes a homeodomain-containing transcription factor which directs the development of the spleen during embryogenesis. While HOX11 expression is normally silenced through an unknown mechanism in all tissues by adulthood, the deregulation of HOX11 expression is associated with leukemia, such as T-cell acute lymphoblastic leukemia. The elucidation of regulatory elements contributing to the molecular mechanism underlying the regulation of HOX11 gene expression is of great importance. Previous reports of HOX11 regulatory elements mainly focused on the 5'-flanking region of HOX11 on the chromosome related to transcriptional control. To expand the search of putative cis-elements involved in HOX11 regulation at the post-transcriptional level, we analyzed HOX11 mRNA 3'-untranslated region (3'UTR) and found an AU-rich region. To characterize this AU-rich region, in vitro analysis of HOX11 mRNA 3'UTR was performed with human RNA-binding protein HuR, which interacts with AU-rich element (ARE) existing in the 3'UTR of many growth factors' and cytokines' mRNAs. Our results showed that the HOX11 mRNA 3'UTR can specifically bind with human HuR protein in vitro. This specific binding could be competed effectively by typical ARE containing RNA. After the deletion of the AU-rich region present in the HOX11 mRNA 3'UTR, the interaction of HOX11 mRNA 3'UTR with HuR protein was abolished. These findings suggest that HOX11 mRNA 3'UTR contains cis-acting element which shares similarity in the action pattern with RE-HuR interactions and may involve in the post-transcriptional regulation of the HOX11 gene.

• 한국작물학회지
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• 제48권
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• pp.41-48
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• 2003

The number of natural products obtained from plants has now reached over 100,000 and new chemical compounds are being discovered ever year. Medicinal and Aromatic plants and their extracts have been used for centuries to relieve pain, aid healing, kill bacteria and insects are important as the antifungal and anti-herbivore agents with further compounds being involved in the symbiotic associations. Although their functions in plants have not been fully established, it is Known that some substances have growth regulatory properties while others are involved in pollination and seed dispersal. The complex nature of these chemicals are usually produced in various types of secretory structures which is an important character of a plant family and also influenced and controlled by genetic and ecological factors. Detailed anatomical description of these structures ave relevant to the market value of the plants, the verification of authenticity of a given species and for the detection of substitution or adulteration. Volatile oils are used for their therapeutic action for flavoring of lemon, in perfumery of rose or as starting materials for the synthesis of other compounds of turpentine. For therapeutic purposes they are administered as inhalations of eucalyptus oil, peppermint oil, as gargles and mouthwashes of thymol and transdermally many essential oils including those of lavender, etc. With these current trend for using volatile components in essential oil will be increasing in the future in Korea and in the world as well.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.178-182
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• 2005

Nitric oxide (NO) produced from endothelial cells plays a critical role in vascular physiology. The regulation of endothelial NO synthase (eNOS) involves various mechanisms including multiple Ser/Thr phosphorylations. Recently, eNOS-Ser617 was newly recognized to be phosphorylated in response to humoral factors including vascular endothelial growth factor. However, it remains unknown whether and how eNOS-Ser617 phosphorylation is stimulated by shear stress, the primary stimulus of endothelial NO production. This issue was explored in the present study using cultured bovine aortic endothelial cells (BAECs). Over-expression of a constitutively active protein kinase B(Akt) mutant in BAECs increased Ser617 phosphorylation while constitutively active protein kinase A mutant had no effect. When BAECs were subjected to an arterial level of laminar shear stress, eNOS-Ser617 phosphorylation was clearly increased in a time-dependent manner. Shear stress also stimulated Akt phosphorylation at Thr308, one of the key regulatory sites. The time courses of eNOS-Ser617 and Akt-Thr308 phosphorylations appeared to be very similar. These results suggested that eNOS-Ser617 phosphorylation, mediated by Akt, is a physiological response to the mechanical shear stress, involved in the regulation of NO production in endothelial cells.

• 지식경영연구
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• 제10권2호
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• pp.15-33
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• 2009

Telecommunications-broadcasting convergence in the domain of IT is a representative phenomenon that is expected to provide the saturated existing markets with a new source of profit. Especially, T-Commerce combines familiarity of TV and immediacy of the Internet which are expected to cover all the users familiar with each media and expand the existing commercial transactions. Telecommunications-broadcasting convergence in Korea, however, is focusing on technical and regulatory aspects so that research on the real users is not up to the mark yet. This is the most fundamental problem in hampering growth in the corresponding service and market. Thus, we are proposing an adoption model on T-Commerce to rapidly expand the convergence service through understanding the potential users. Perceived utilitarian and hedonic values, perceived interactivity, media substitution and personal innovativeness have been examined as the factors influencing the users' intention to adopt a new convergence service. As a result of empirical analysis, it is verified that perceived utilitarian and hedonic values and personal innovativeness directly influenced the users' intention to adopt whereas perceived interactivity had indirect affect on them. T-Commerce service providers should not only emphasize on the benefit that the older media could not provide the users with, but also provide them with more pleasure and entertaining experience during the course of satisfying the users' needs to distinguish T-Commerce from the other existing media.

• Interdisciplinary Bio Central
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• 제4권2호
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• pp.3.1-3.7
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• 2012

Epidermal growth factor receptor (EGFR) is a member of the ErbB family (ErbB1-4) of receptor tyrosine kinases (RTKs). EGFR controls numerous physiological functions, including cell proliferation, migration, differentiation and survival. Importantly, aberrant signaling by EGFR has been linked to human cancers in which EGFR and its various ligands are frequently overexpressed or mutated. EGFR coordinates activation of multiple downstream factors and is subject of various regulatory processes as it mediates biology of the cell it resides in. Therefore, many studies have been devoted to understanding EGFR biology and targeting the protein for the goal of controlling tumor in clinical settings. Endocytic regulation of EGFR offers a promising area for targeting EGFR activity. Upon ligand binding, the activated receptor undergoes endocytosis and becomes degraded in lysosome, thereby terminating the signal. En route to lysosome, the receptor becomes engaged in activating various signaling pathways including PI-3K, MAPK and Src, and endocytosis may offer both spatial and temporal regulation of downstream target activation. Therefore, endocytosis is an important regulator of EGFR signaling, and increasing emphasis is being placed on endocytosis in terms of cancer treatment and understanding of the disease. In this review, EGFR signaling pathway and its intricate regulation by endocytosis will be discussed.

• BMB Reports
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• 제45권10호
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• pp.571-576
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• 2012

Radiotherapy is considered to cause detrimental effects on bone tissue eventually increasing bone loss and fracture risk. However, there is a great controversy on the real effects of irradiation itself on osteoblasts, and the mechanisms by which irradiation affects osteoblast differentiation and mineralization are not completely understood. We explored how X-ray radiation influences differentiation and bone-specific gene expression in mouse calvarial osteoblasts. Irradiation at 2 Gy not only increased differentiation and mineralization of the cells, but also upregulated the expression of alkaline phosphatase, type I collagen, osteopontin, and osteocalcin at early stages of differentiation. However, irradiation at higher doses (>2 Gy) did not stimulate osteoblast differentiation, rather it suppressed DNA synthesis by the cells without a toxic effect. Additional experiments suggested that transforming growth factor-beta 1 and runt-transcription factor 2 play important roles in irradiation- stimulated bone differentiation by acting as upstream regulators of bone-specific markers.