• Molecules and Cells
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• 제38권1호
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• pp.20-25
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• 2015

TGF-${\beta}$ regulates pleiotropic cellular responses including cell growth, differentiation, migration, apoptosis, extracellular matrix production, and many other biological processes. Although non-Smad signaling pathways are being increasingly reported to play many roles in TGF-${\beta}$-mediated biological processes, Smads, especially receptor-regulated Smads (R-Smads), still play a central mediatory role in TGF-${\beta}$ signaling for epithelial-mesenchymal transition. Thus, the biological activities of R-Smads are tightly regulated at multiple points. Inhibitory Smad (I-Smad also called Smad7) acts as a critical endogenous negative feedback regulator of Smad-signaling pathways by inhibiting R-Smad phosphorylation and by inducing activated type I TGF-${\beta}$ receptor degradation. Roles played by Smad7 in health and disease are being increasingly reported, but the molecular mechanisms that regulate Smad7 are not well understood. In this study, we show that E3 ubiquitin ligase Itch acts as a positive regulator of TGF-${\beta}$ signaling and of subsequent EMT-related gene expression. Interestingly, the Itch-mediated positive regulation of TGF-${\beta}$ signaling was found to be dependent on Smad7 ubiquitination and its subsequent degradation. Further study revealed Itch acts as an E3 ubiquitin ligase for Smad7 polyubiquitination, and thus, that Itch is an important regulator of Smad7 activity and a positive regulator of TGF-${\beta}$ signaling and of TGF-${\beta}$-mediated biological processes. Accordingly, the study uncovers a novel regulatory mechanism whereby Smad7 is controlled by Itch.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.261-261
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• 2006

Membranes are a central feature of all biological systems and their ability to control many cellular processes is critically important. As a result, a better understanding of how molecules bind to biological membranes is an active area of research. In this report, the interaction between our biomimetic structures and different biological membranes is reported using both model vesicle and in vitro bacterial cell experiments. These results show that lipid composition is more important for selectivity than overall net charge. An effort is made to connect model vesicle studies with in vitro data and naturally occurring lipid compositions.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.48-48
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• 2002

Glutathione (GSH) is most prevalent reducing thiols in eukaryotic cells and known that participates in many cellular processes. It was found that total amount of glutathione and the ratio of reduced to oxidized glutathione during development of Dictyostelium discoideum increase at the initial stage of the aggregation of amoeba.(omitted)

• Genomics & Informatics
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• 제3권2호
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• pp.47-51
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• 2005

Molecular mechanisms of biological processes are typically represented as 'pathways' that have a graph­analogical network structure. However, due to the diversity of topics that pathways cover, their constituent biological entities are highly diverse and the semantics is embedded implicitly. The kinds of interactions that connect biological entities are likewise diverse. Consequently, how to model or process pathway data is not a trivial issue. In this review article, we give an overview of the challenges in pathway database development by taking the INOH project as an example.

• Genes and Genomics
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• 제40권11호
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• pp.1199-1211
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• 2018

Soil acidification is one of major problems limiting crop growth and especially becoming increasingly serious in China owing to excessive use of nitrogen fertilizer. Only the STOP1 of Arabidopsis was identified clearly sensitive to proton rhizotoxicity and the molecular mechanism for proton toxicity tolerance of plants is still poorly understood. The main objective of this study was to investigate the transcriptomic change in plants under the low pH stress. The low pH as a single factor was employed to induce the response of the wheat seedling roots. Wheat cDNA microarray was used to identify differentially expressed genes (DEGs). A total of 1057 DEGs were identified, of which 761 genes were up-regulated and 296 were down-regulated. The greater percentage of up-regulated genes involved in developmental processes, immune system processes, multi-organism processes, positive regulation of biological processes and metabolic processes of the biological processes. The more proportion of down-regulation genes belong to the molecular function category including transporter activity, antioxidant activity and molecular transducer activity and to the extracellular region of the cellular components category. Moreover, most genes among 41 genes involved in ion binding, 17 WAKY transcription factor genes and 17 genes related to transport activity were up-regulated. KEGG analysis showed that the jasmonate signal transduction and flavonoid biosynthesis might play important roles in response to the low pH stress in wheat seedling roots. Based on the data, it is can be deduced that WRKY transcription factors might play a critical role in the transcriptional regulation, and the alkalifying of the rhizosphere might be the earliest response process to low pH stress in wheat seedling roots. These results provide a basis to reveal the molecular mechanism of proton toxicity tolerance in plants.

• 청정기술
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• 제28권3호
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• pp.232-237
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• 2022

해조류 바이오매스 중 갈조류의 주요 구성 성분인 알긴산은 다양한 산업에서 널리 사용되어지며, 촉매적 저분자화를 통해 당, 당알코올, 퓨란계, 그리고 유기산과 같은 고부가가치 화합물로 전환할 수 있다. 본 연구에서는 루테늄 담지 활성탄과 마그네시아를 혼합하여 알긴산 저분자화 반응에 적용하고자 하였다. 이러한 불균일계 촉매 시스템은 생성물에 대한 분리가 용이하고 정제 과정의 간소화가 장점으로 작용한다. 반응 결과, 탄소 수 5개 이하의 저분자량 알코올 및 유기산이 생성되었으며, 최적의 반응 조건 탐색을 통해 최종적으로 1 wt% 알긴산 수용액 30 mL, 루테늄 담지 활성탄 100 mg, 마그네시아 100 mg, 반응 온도 210 ℃, 반응 시간 1 h의 반응 조건에서 29.8%의 알코올에 대한 탄소 수율과 43.8%의 알코올 포함 액상 생성물에 대한 총 탄소 수율을 확보하였다.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.1873-1878
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• 2012

Polyamides have great potentials for diverse applications and the present production of their monomers mostly relies on resources from fossil fuel. Starting from undecylenic acid, a natural resource, we have developed both divergent and efficient processes for $C_{10}$, $C_{11}$ and $C_{12}$ ${\omega}$-amino acid and ${\alpha},{\omega}$-dicarboxylic acid monomers of the polyamides.

• 청정기술
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• 제12권2호
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• pp.53-61
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• 2006

생분해성 고분자인 Poly(lactide-co-glycolide) (PLGA)와 약물 단백질로 약물 중합체를 만들기 위하여 초임계 나노 입자 제조 공정중 하나인 PGSS법을 이용하여 연구를 수행하였다. 초임계 이산화탄소에 의해서 고분자 PLGA의 유리전이온도($T_g$)를 강하시켜 가소화시키면서 단백질을 용기 내에서 혼합하였다. 고분자 PLGA에 캡슐화 된 단백질의 입자를 얻기 위해 고압 용기에 들어있는 시료를 노즐을 통하여 대기압으로 이산화탄소를 분사시켰다. 입자의 형태, 입자 크기 그리고 크기 분포에 대한 영향을 알아보기 위해서 고압 용기 안에서 초임계 이산화탄소를 이용하여 공정변수들을 조작함으로서 PGSS 실험을 하였다. 입자는 거칠고 불규칙하며 표면에 기공이 생성되었음을 확인하였다. 제조된 입자의 크기와 크기분포는 과포화도, 핵 생성시간 등으로 설명하였다. 제조된 입자 내의 protein의 활성도 저하는 거의 없었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권3호
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• pp.73-81
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• 2013

Various remediation methods have been applied to clean soils contaminated with pollutants. They remove contaminants from the soils by utilizing physicochemical, biological, and thermal processes and can satisfy soil remediation standards within a limited time; however, they also have an effect on the biological functions of soils by changing soil properties. In this study, changes of the biological properties of soils before and after treatment with three frequently used remediation methods-soil washing, land farming, and thermal desorption-were monitored to investigate the effects of remediation methods on soil biological functions. Total microbial number and soil enzyme activities, germination rate and growth of Brassica juncea, biomass change of Eisenia andrei were examined the effects on soil microorganisms, plant, and soil organisms, respectively. After soil washing, the germination rate of Brassica juncea increased but the above-ground growth and total microbial number decreased. Dehydrogenase activity, germination rate and above-ground growth increased in both land farming and thermal desorption treated soil. Although the growth of Eisenia andrei in thermal desorption treated soil was higher than any other treatment, it was still lower than that in non-contaminated soil. These results show that the remediation processes used to clean contaminated soil also affect soil biological functions. To utilize the cleaned soil for healthy and more value-added purposes, soil improvement and process development are needed.

• Mass Spectrometry Letters
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• 제7권1호
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• pp.21-25
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• 2016

Dual-channel nano-electrospray has recently become an ionization technique of great promise especially in biological mass spectrometry. This unique approach takes advantage of the mixing processes that occurs during electrospray. Understanding in more detail the fundamental principles influencing spray formation further study of the origins of the mixing processes: (1) in a Taylor cone region, (2) in charged droplets or (3) in both environments. The dual-channel emitters were made from borosilicate theta-shape glass tubes (O.D. 1.2 mm) and had a tip diameters of less than 4 μm. Electrical contact was achived by deposition of a thin film of an appropriate metal onto the surface of the emitter. The experimental investigation of the Taylor cone formation in a dual-channel electrospray emitter has been carried out by injection of polystyrene beads (diameter 3 μm) at very low concentrations into one of the channels of the non-tapered theta-glass tubes. High-speed camera experiments were set up to visualize the mixing processes in Taylor cone regions for dual-channel emitters. Mass spectra from dual nano-electrospray are presented.