• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.408-412
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• 2008

FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1) in Arabidopsis are homologous proteins that perform opposite functions: FT is an activator of flowering, and TFL1 is a repressor. It was shown before that change of a single amino acid (His88) of TFL1 to the corresponding amino acid (Tyr) of FT is enough to convert the floral repressor to an activator. However, structural basis of the functional conversion has not been understood. In our molecular dynamics simulations on modified TFL1 proteins, a hydrogen bond present in native TFL1 between the His88 residue and a residue (Asp144) in a neighboring external loop became broken by change of His88 to Tyr. This breakage induced conformational change of the external loop whose structure was previously reported to be another key functional determinant. These findings reveal that the two important factors determining the functional specificities of the floral regulators, the key amino acid (His88) and the external loop, are correlated, and the key amino acid determines the functional specificity indirectly by affecting the conformation of the external loop.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1993년도 학술대회지
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• pp.143-149
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• 1993

Ginseng root explants and calli induced from selected cell lines were cultured on modified Murashige and Skoog's media supplemented with different concentrations of organic or inorganic compounds and plant growth requlators to clarify the effects of chemical composition and plant growth regulators in the medium on the growth of ginseng calli and the production of ginseng saponin. For optimum growth of calli, the concentrations of 2, 4-D and sucrose were the range of 1 to 3 mg/${\ell}$l and 1 to $3\%,$ respectively. And it was clarified that sucrose, nitrogen, phosphate, calcium, magmesian plant growth regulators and their concentrations influcenced the relative biosynthesis of saponin in tissue cultures of Panax ginseng. The patterns of ginsenosides, pharmacologically useful component, were different among the cell lines and contents of ginsenosides were much higher in selected cell lines than in original cell line.

• 한국작물학회지
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• 제40권6호
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• pp.697-704
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• 1995

벼 무논 골뿌림 재배시 물관리방법 및 생장조절기 처리가 생육 및 도복에 미치는 영향을 구명하고자 1994년에 미사질양토(전북통)인 호남 농업시험장 시험포장에서 동진벼를 5월 11일에 골깊이 4cm에 파종하고 중간낙수 회수 및 생장조절제를 처리하여 생육 및 도복형질을 검토한 결과를 요약하면 다음과 같다. 1. 상시심수에 비하여 2회 낙수구에서 간장이 짧았으며 생장조절제에는 Inbenfide G. > IMP G. > 무처리 순으로 간장이 단축되었다. 2. 상시심수에 비하여 2회 낙수구에서 간벽이 두껍고 뿌리량 및 뿌리의 심층분포 비율이 높았으나 생장조절제간에는 일정한 경향이 없었다. 3. 도복지수는 상시심수보다 2회 낙수구가 적고 생장조절제에는 세리타드 > 키타진 > 무처리의 순으로 적었으며 도복은 2회 낙수구에서는 생장조절제 무처리에서만 약간 발생하였으나 상시심수구에서는 무처리 > IBP G.> Inabenfide G.의 순으로 도복발생이 심하였다. 4. 쌀수량은 상시심수구의 생장조절제 무처리에서만 감수하였고 기타 처리에는 별 차이가 없었다 5. 따라서 벼 무논골뿌림 재배시는 생장조절제를 처리하지 않아도 2회(파종후 30일과 50일)에 실금갈 정도로 중간낙수만 하면 도복을 방지 할 수 있을 것으로 생각된다.

• BMB Reports
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• 제49권1호
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• pp.11-17
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• 2016

The gastrointestinal tract forms the largest surface in our body with constantly being exposed to various antigens, which provides unique microenvironment for the immune system in the intestine. Accordingly, the gut epithelium harbors the most T lymphocytes in the body as intraepithelial lymphocytes (IELs), which are phenotypically and functionally heterogeneous populations, distinct from the conventional mature T cells in the periphery. IELs arise either from pre-committed thymic precursors (natural IELs) or from conventional CD4 or CD8αβ T cells in response to peripheral antigens (induced IELs), both of which commonly express CD8α homodimers (CD8αα). Although lineage commitment to either conventional CD4 T helper (Th) or cytotoxic CD8αβ T cells as well as their respective co-receptor expression are mutually exclusive and irreversible process, CD4 T cells can be redirected to the CD8 IELs with high cytolytic activity upon migration to the gut epithelium. Recent reports show that master transcription factors for CD4 and CD8 T cells, ThPOK (Th-inducing BTB/POZ-Kruppel-like factor) and Runx3 (Runt related transcription factor 3), respectively, are the key regulators for re-programming of CD4 T cells to CD8 lineage in the intestinal epithelium. This review will focus on the unique differentiation process of IELs, particularly lineage re-commitment of CD4 IELs. [BMB Reports 2016; 49(1): 11-17]

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2004년도 제46차 춘계학술대회
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• pp.88-89
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• 2004

• 한국작물학회:학술대회논문집
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• 한국작물학회 1996년도 춘계 학술대회지
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• pp.30-31
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• 1996

• 생명과학회지
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• 제16권3호
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• pp.447-453
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• 2006

Histidine kinase는 식물의 신호전달기작에서 매우 중요한 역할을 한다. 본 연구에서는 애기장대 histidine kinase 3 (AHK3)의 식물체내에서의 기능을 조사하였으며 이 유전자의 결손 돌연변이체인 ahk3에 trans-zeatin (t-zeatin)을 처리하여 유전자와 단백질의 발현양상을 분석하였다. ahk3는 야생형 식물체에 비하여 캘러스 형성, 유모의 성장, 잎의 노화과정에서 t-zeatin에 대한 감수성이 줄어들었다. 프로테옴 분석 결과 eukaryotic translation initiation factor 5A-2, auxin binding glutathione S-transferase, NDPK1 등은 야생형의 애기장대에서는 t-zeatin에 의하여 발현이 증가하는 반면 ahk3에서는 증가하지 않는 것으로 나타났다. 또한 cytokinin처리에 의하여 발현이 증가하는 것으로 보고된 A-type response regulator들 중에서 ARR4와 ARR16의 발현양이 ahk3에서는 현저하게 감소하는 것으로 나타났다. 이러한 결과들은 AHK3가 cytonin신호전달기작에서 매우 중요한 역할을 하며, 프로테옴 분석에 의하여 동정된 단백질들과 ARR4, ARR16은 AHK3에 의해 매개되는 cytokinin 신호전달과정에서 중요한 역할을 할 것으로 생각된다.

• IMMUNE NETWORK
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• 제12권3호
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• pp.71-83
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• 2012

T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse.

• BMB Reports
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• 제43권3호
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• pp.205-211
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• 2010

Sprouty (Spry) proteins have previously been suggested as negative regulators of the MAPK pathway through interaction with Raf-1. However, the molecular basis of this inhibition has not been elucidated. In this study, we used cells expressing FLAGtagged Raf-1 with point mutations at known phosphorylation sites to reveal that activation of Raf-1 mutants does not correlate with their degree of interaction with Spry2. The association of Raf-1 with Spry2 in intact cells was further corroborated by immunofluorescence colocalization. Additionally, there was no significant change observed in the strength of interaction between Raf-1 mutants and Spry2 after paclitaxel treatment despite differences in the activation levels of these mutants. Thus, our study provides the evidence that Spry2 does not directly regulate Raf-1 kinase activity, but instead acts as a scaffolding protein that assists interactions between Raf-1 kinase and its direct regulators.

• BMB Reports
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• 제52권10호
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• pp.619-624
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• 2019

The primary cilium is a microtubule-based structure projecting from a cell. Although the primary cilium shows no motility, it can recognize environmental stimuli. Thus, ciliary defects cause severe abnormalities called ciliopathies. Ciliogenesis is a very complex process and involves a myriad of components and regulators. In order to excavate the novel positive regulators of ciliogenesis, we performed mRNA microarray using starved NIH/3T3 cells. We selected 62 murine genes with corresponding human orthologs, with significantly upregulated expression at 24 h after serum withdrawal. Finally, calpain-6 was selected as a positive regulator of ciliogenesis. We found that calpain-6 deficiency reduced the percentage of ciliated cells and impaired sonic hedgehog signaling. It has been speculated that this defect might be associated with decreased levels of ${\alpha}-tubulin$ acetylation at lysine 40. This is the first study to report a novel role of calpain-6 in the formation of primary cilia.