• Mycobiology
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• 제39권4호
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• pp.243-248
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• 2011

The ubiquitin-proteasome system is one of the major protein turnover mechanisms that plays important roles in the regulation of a variety of cellular functions. It is composed of E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 ubiquitin ligases that transfer ubiquitin to the substrates that are subjected to degradation in the 26S proteasome. The Skp1, Cullin, F-box protein (SCF) E3 ligases are the largest E3 gene family, in which the F-box protein is the key component to determine substrate specificity. Although the SCF E3 ligase and its F-box proteins have been extensively studied in the model yeast Saccharomyces cerevisiae, only limited studies have been reported on the role of F-box proteins in other fungi. Recently, a number of studies revealed that F-box proteins are required for fungal pathogenicity. In this communication, we review the current understanding of F-box proteins in pathogenic fungi.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권3호
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• pp.198-206
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• 2009

Purpose: The aims of this study were to assess the in vitro co-culturing pattern of isolated skin-derived precursor cells (SKPs) with a mixed demineralized bone (DMB) and fibrin glue scaffold and to evaluate in vivo osteogenesis after transplantation of autogenous SKPs with a these mixed scaffold in the animal's mandibular defects. Materials and Methods: We isolated SKPs from the ears of adult 4 miniature pigs. The isolated SKPs were co-cultured with a mixed DMB and fibrin glue scaffold in a non-osteogenic medium for 1, 2, and 4 weeks. Histological characteristics of in vitro co-cultured cells and scaffold were evaluated. $1{\times}10^7\;cells/100\;{\mu}l$ of autogenous porcine SKPs were grafted into the mandibular defects with a DMB and fibrin glue scaffold. In the control sites, only a scaffold was grafted, without SKPs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: Homogeneously shaped skin-derived cells were isolated from porcine ear skin after 3 or 4 weeks of primary culture. In vitro osteogenic differentiation of SKPs was observed after co-culturing with a DMB and fibrin glue scaffold in a non-osteogenic medium. Von Kossa-positive bone minerals were also noted in the co-cultured medium at 4 weeks. As the culture time progressed, the number of observable cells increased. Trabecular new bone formation and osteocalcin expression were more pronounced in the SKP-grafted group compared to the control group. Conclusion: These findings suggest that autogenous SKP grafting with a DMB and fibrin glue scaffold can serve as a useful alternative to bone grafting technique.

• 한국환경생태학회지
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• 제30권4호
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• pp.793-799
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• 2016

본 연구는 도심지 공원 내 식재된 버즘나무와 느릅나무를 대상으로 수관 내부의 온도, 풍량, 풍속 등 미기후 인자간의 상호관계를 규명하는데 그 목적이 있다. 현장조사는 여름철, 8월 한 달간 오전 09시부터 오후 06시까지 1시간 간격으로 측정하였다. 미기후 인자 측정 항목은 광량자센서(PAR Quantum Sensor SKP215), 정밀온도계측기(Pt1000-Sensor), 풍량풍속계(1467 G4 & HG4)를 이용하여 온도, 광량, 풍량 및 풍속 데이터를 수집하였다. 분석 결과, 버즘나무와 느릅나무는 두 종 모두 외부 온도에 비해 수관 내부에서 냉각효과가 있음이 입증되었다. 수관 내부의 냉각효과는 대기 중의 풍량과 풍속이 있을 때 더 효과적이었다. 바람이 있을 때, 버즘나무는 풍량에 의해 수관 내부의 온도가 더 낮아지며, 느릅나무는 풍속에 의해 수관 내부의 온도가 더 낮아지는 것으로 확인되었다. 바람이 없을 때, 두 종간 수관 내 평균온도 변화는 평균적으로 느릅나무가 $-0.9^{\circ}C$, 버즘나무가 $-0.958^{\circ}C$로 버즘나무가 느릅나무보다 식재 공간 내 온도를 낮추는데 비교적 더 효과적이었다. 본 연구는 도심 내 수목이 종별로 미기후에 미치는 영향에 차이가 있으며 또한, 수목의 미기후 형성에 영향을 미치는 인자들이 수종별로 다를 수 있음을 밝혔다는데서 의의가 있다. 향후 활엽교목 이외에 상록수, 관목류 등 다양한 수종 등에 대한 후속 연구가 필요하며, 이를 통해 도시 녹지 공간 내 미기후 조절에 효과적인 조경수를 보급하는데 기여할 것으로 사료된다.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.275-280
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• 2010

Actinobacillus actinomycetemcomitans is a gram-negative, nonmotile coccobacillus bacterium that is associated with several human diseases, including endocarditis, meningitis, osteomyelitis, subcutaneous abscesses and periodontal diseases. A full-length Omp1-like protein gene from A. actinomycetemcomitans was cloned into a pQE30 vector and overexpressed in Escherichia coli BL21(DE3) cells. The protein revealed sequence homologies to Seventeen kilodalton proteins (Skp) from Pasteurella multocida and E. coli that have been characterized as periplasmic chaperones. This soluble Omp1-like protein was successfully purified to homogeneity for further folding and functional studies. The purity, identity, and conformation of the protein were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization mass spectrometry, circular dichroism, fluorescence spectroscopic, and differential scanning calorimetric studies. We showed that the protein formed an oligomer larger than a tetramer. We found, further, that it is comprised of mostly $\alpha$-helices and boasts high thermal stability.

• 한국정보기술학회논문지
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• 제17권1호
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• pp.149-156
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• 2019

혼합현실 기술(MR)은 4차산업혁명 요소기술 중의 하나로 크게 부각되고 있다. MR 기술은 단순한 디지털 콘텐츠 산업으로서 만이 아니라 건축분야, 관광분야, 의료분야, 각종 교육분야에서 널리 적용되고 있으며 그 활용성을 넓혀가고 있다. 본 논문에서는 MR 단말기와 PC, 모바일 단말기 등 이기종 기기를 연동하는 건축분야 활용을 위한 협업 서비스 플랫폼을 제안하고 시작품 개발과 이의 검증을 수행하였다. 결과, 건축에서 주로 사용되는 skp확장자를 이용하는 3D 모델을 서비스 시작품을 이용하여 MR 단말기인 홀로렌즈를 대상으로 한 MR 콘텐츠 생성을 수행하여 변환시간 및 정상 동작을 확인하였다.

• International Journal of Oral Biology
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• 제41권2호
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• pp.69-74
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• 2016

Skin-derived precursors (SKPs) have potential to differentiate to various cell types including osteoblasts, adipocytes and neurons. SKPs are a candidate for cell-based therapy since they are easily accessible and have multipotency. Most mammalian cells are exposed to a low oxygen environment with 1 to 5% $O_2$ concentration in vivo, while 21% $O_2$ concentration is common in in vitro culture. The difference between in vitro and in vivo $O_2$ concentration may affect to the behavior of cultured cells. In this report, we investigated the effect of hypoxic condition on stemness and proliferation of SKPs. The results indicated that SKPs exposed to hypoxic condition for 5 days showed no change in proliferation. In terms of mRNA expression, hypoxia maintained expression of stemness markers; whereas, oncogenes, such as Klf4 and c-Myc, were downregulated, and the expression of Nestin, related to cancer migration, was also downregulated. Thus, SKPs cultured in hypoxia may reduce the risk of cancer in SKP cell-based therapy.

• Molecules and Cells
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• 제38권10호
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• pp.829-835
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• 2015

It has been suggested that AUXIN BINDING PROTEIN 1 (ABP1) functions as an apoplastic auxin receptor, and is known to be involved in the post-transcriptional process, and largely independent of the already well-known SKP-cullin-F-box-transport inhibitor response (TIR1) /auxin signaling F-box (AFB) ($SCF^{TIR1/AFB}$) pathway. In the past 10 years, several key components downstream of ABP1 have been reported. After perceiving the auxin signal, ABP1 interacts, directly or indirectly, with plasma membrane (PM)-localized transmembrane proteins, transmembrane kinase (TMK) or SPIKE1 (SPK1), or other unidentified proteins, which transfer the signal into the cell to the Rho of plants (ROP). ROPs interact with their effectors, such as the ROP interactive CRIB motif-containing protein (RIC), to regulate the endocytosis/exocytosis of the auxin efflux carrier PIN-FORMED (PIN) proteins to mediate polar auxin transport across the PM. Additionally, ABP1 is a negative regulator of the traditional $SCF^{TIR1/AFB}$ auxin signaling pathway. However, Gao et al. (2015) very recently reported that ABP1 is not a key component in auxin signaling, and the famous abp1-1 and abp1-5 mutant Arabidopsis lines are being called into question because of possible additional mutantion sites, making it necessary to reevaluate ABP1. In this review, we will provide a brief overview of the history of ABP1 research.

• Animal cells and systems
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• 제16권4호
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• pp.280-288
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• 2012

Targeted degradation of proteins through ubiquitin-mediated proteolysis is an important control mechanism in various cellular processes. The process of ubiquitin conjugation is achieved by three enzyme complexes, among which the ubiquitin ligase complex (E3) is in charge of substrate specificity. The SCF (SKP1-CUL1-F-box) family portrays the largest and the most characterized member of the E3 ligases. For each SCF complex, the ubiquitination target is recognized by the F-box protein subunit, which interacts with the substrate through a unique C-terminal domain. We have characterized a novel F-box protein CFL-1 that represents a single LRR-type F-box (FBXL) in the Caenorhabditis elegans genome. CFL-1 is highly homologous to FBXL20 and FBXL2 of mammals, which are known to regulate synaptic vesicle release and cell cycle, respectively. A green fluorescence protein (GFP)-reporter gene fused to the cfl-1 promoter showed restricted expression around the amphid and the anus. Modulation of CFL-1 activity by RNAi affected the time interval between defecations. RNAi-treated worms also exhibited reduced tendency to form dauer when exposed to daumone. The potential involvement of CFL-1 in the control of defecation and pheromone response adds to the ever expanding list of cellular processes controlled by ubiquitin-mediated proteolysis in C. elegans. We suggest that CFL-1, as a single LRR-type F-box protein in C. elegans, may portray a prototype gene exerting diverse functions that are allocated among multiple FBXLs in higher organisms.

• 동의생리병리학회지
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• 제20권3호
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• pp.701-709
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• 2006

The Rhus verniciflua Stokes (乾漆-RVS) has been used in traditional East Asia medicine for the therapy of gastritis, stomach cancer, although the mechanism for the biological activity is unclear. In the present study aims to investigate RVS extract contributes to growth inhibitory effect and it's the molecular mechanism on the human gastric cancer cells. AGS (gastric cancer cells) and RIEI (normal cells) were treated to different concentrations and periods of RVS extract $(10{\;}{\sim{{\;}100{\;}ug/mil)$. Growth inhibitory effect was analyzed by measuring FACS study and MTS assay. Cell cycle inhibition was confirmed by measuring CDK2 kinase activity by immunoprecipitation and kinase assay. And apoptosis was confirmed by surveying caspase cascades activation using a pan caspase inhibitor Exposure to RVS extract (50 ug/mll) resulted in a synergistic inhibitory effect on cell growth in AGS cells. Growth inhibition was related with the inhibition of proliferation and induction of apoptosis. The extract induces Gl -cell cycle arrest through the regulation of cyclins, the induction of p27kip1, and the decrease CDK2 kinase activity. And upregulated p27kip1 level is caused by protein stability increment by the reduction of S-phase kinase-associated protein 2 (Skp2), a key molecule related with p27kip1 ubiquitination and degradation, and do novo protein synthesis. Besides, 乾漆 extract induces apoptosis through the expression of Bax, poly(ADP-ribose) polymerase (PARP) and activation of caspase-3. RVS extract induces Gl -cell cycle arrest via accumulation of p27kip1 and apoptosis in human gastric cancer cells but not in normal cells, therefore we suggest that the extract can be used as a novel class of anti-cancer drugs.

• The Plant Pathology Journal
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• 제36권1호
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• pp.43-53
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• 2020

Ralstonia solanacearum (Rso) is a causal agent of bacterial wilt in Solanaceae crops worldwide including Republic of Korea. Rso virulence predominantly relies on type III secreted effectors (T3Es). However, only a handful of Rso T3Es have been characterized. In this study, we investigated subcellular localization of and manipulation of plant immunity by 8 Rso T3Es predicted to harbor a nuclear localization signal (NLS). While 2 of these T3Es elicited cell death in both Nicotiana benthamiana and N. tabacum, only one was dependent on suppressor of G2 allele of skp1 (SGT1), a molecular chaperone of nucleotide-binding and leucine-rich repeat immune receptors. We also identified T3Es that differentially regulate flg22-induced reactive oxygen species production and gene expression. Interestingly, several of the NLS-containing T3Es translationally fused with yellow fluorescent protein accumulated in subcellular compartments other than the cell nucleus. Our findings bring new clues to decipher Rso T3E function in planta.