• Animal cells and systems
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• 제2권1호
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• pp.117-122
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• 1998

D-raf, a Drosophila homolog of the human c-raf-1, is known as a signal transducer in cell proliferation and differentiation. A previous study found that the D-raf gene expression is regulated by the DNA replication-related element (DRE)/DRE-binding factor (DREF) system. In this study, we found the sequences homologous to transcription factor C/EBP, MyoD, STAT and Myc recognition sites in the D-raf promoter. We have generated various base substitutional mutations in these recognition sites and subsequently examined their effects on D-raf promoter activity through transient CAT assays in Kc cells with reporter plasmids p5'-878DrafCAT carrying the mutations in these binding sites. Through gel mobility shift assay using nuclear extracts of Kc cells, we detected factors binding to these recognition sites. Our results show that transcription factor C/EBP, STAT and Myc binding sites in D-raf promoter region play a positive role in transcriptional regulation of the D-raf gene and the Myo D binding site plays a negative role.

• Animal cells and systems
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• 제1권4호
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• pp.637-640
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• 1997

Raf-1, a cytoplasmic serine/threonine protein kinase, serves as a central intermediate in many signaling pathways in cell proliferation, differentiation, and development. In this study, we investigated that B-raf, Drosophila homolog of the human c-raf-1, is involved in ultraviolet (UV) responsive events by using hypomorphic mutant $D-raf^{c110}$ and Draf-lacZ transgenic fly. At first, effect of UV damage on the survival of wild-type and $D-raf^{C110}$ strains was examined. In terms of $1/LD_{50}$ value, the relative ratio of UV sensitivities of wild-type versus $D-raf^{C110}$ strain was 1 : 2.2. By using quantitative $\beta$-galactosidase activity analysis, transcriptional activity of the D-raf gene promoter was also examined in UV-irradiated Draf-lacZ transgenic larvae. UV irradiation increased the expression of lacZ reporter gene in Draf-lacZ transgenic fly. However, in $D-raf^{C110}$ strain the transcriptional activity of D-raf gene promoter by UV irradiation was extensively reduced. Results obtained in this study suggest that D-raf plays a role in UV response, leading to better survival of Drosophila to UV damage.

• 생명과학회지
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• 제9권1호
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• pp.50-57
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• 1999

STAT들은 다양한 cytokine이나 성장호르몬 등에 의해 활성화되어 핵으로 빠르게 이동되어 유전자 발현을 조절한다. 우리는 D-raf 유전자의 5' 발현조절영역에서 STAT결합부위 염기서열을 발견하였다. 본 연구는 D-raf 유전자발현조절에 있어서 STAT결합부위의 역할을 형질전환 초파리를 사용하여 조사하였다. STAT결합부위에 염기치환돌연변이를 도입시킨 D-raf promoter부분을 P인자 벡터의 IacZ유전자에 융합시킴으로써 리포터 플라스미드 pDraf-STATmut-lacZ를 제작하였다. 이 리포터 플라스미드를 이용하여 얻은 Draf-STATmut-lacZ형질전환 초파리의 lacZ발현을 발생단계별, 조직별로 조사한 결과, 거의 모든 발생단계에서 정상형 Draf-lacZ 형질전환 초파리의 lacZ발현에 비해 크게 감소하였다. 본 연구결과들은 STAT결합배열 부위가 D-raf유전자발현조절에 있어서 중요한 역할을 함을 개체수준에서 증명하고 있다.

• Journal of Life Science
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• 제9권2호
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• pp.52-56
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• 1999

The Raf, a cytoplasmic serine/thereonine protein kinase, acts as an important mediator of signals involving cell proliferation, differentiation and development. Multiple regulatory elements should participate in the expression of D-raf, Drosophila homolog of human c-raf-1. In order to search regulatory factors involved in the D-raf promoter activation, we accomplished the yeast one-hybrid screening using D-raf promoter region from bp-330 to -309 with respect to the transcription initiation site as bait. After screening, sixteen independent positive clones of ${\beta}$-galactosidase activties were identified and sequenced. Two clones having 94-98% identity with daughterless and one clone having 93% identity with escargot by Blast search among these clones were screened.

• Animal cells and systems
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• 제1권1호
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• pp.151-155
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• 1997

Promoter of the Drosophila proliferating cell nuclear antigen (PCNA) gene contains DRE (Drosophila DNA replication-related element) required for the high level expression of replication-related genes. Recently, we found that promoter region of the D-raf (a Drosophila homolog of the human c-raf-1) contains two sequences homologous to the DRE and demonstrated the DRE/DREF (DRE-binding factor) involvement in regulation of the D-raf gene. In this study, using ursolic acid (UA), a pentacyclic triterpene acid reported to possess antitumor activities, we examined effects of UA on proliferation of the Drosophila cultured Kc cells and on expression of the PCNA and D-raf genes. UA showed an inhibitory effect on proliferation of the Kc cells in a concentration-dependent manner in DNA content assays and [3H]thymidine incorporation assays. The IC50 value of anti-proliferative effects of UA in DNA content assays was about 7.5uM. UA showed inhibitory effects on expression of the PCNA as well as on that of the D-raf, which were examined with the reporter plasmic p5'-168DPCNACAT or p5'-878DrafCAT, respectively. The results obtained in the present study suggest that expression of the PCNA and D-raf genes is coordinately regulated in at least UA-treated Kc cells and that down-regulation of expression of the PCNA and D-raf genes might be related with the antitumor activities of UA.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.254-258
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• 2007

Five flavonoids, isorhamnetin 3-O-${\beta}$-D-galactosyl-4'-O-${\beta}$-D-glucoside (1), isorhamnetin 3,4'-di-O-${\beta}$-D-glucoside (2), isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl)glucosyl-4'-O-${\beta}$-D-glucoside (3), isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl)glucoside (4), and isorhamnetin 3-O-${\beta}$-D-(6-O-${\alpha}$-L-rhamnosyl) galactoside (5) were isolated from the stems of Opuntia humifusa (Raf.) Raf. and their structures were identified based on LC-MS and NMR data.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.301.1-301
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• 1997

No Abstract, See Full Text

• BMB Reports
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• 제51권3호
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• pp.119-125
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• 2018

The Hippo pathway plays prominent and widespread roles in various forms of human carcinogenesis. Specifically, the Yes-associated protein (YAP), a downstream effector of the Hippo pathway, can lead to excessive cell proliferation and the inhibition of apoptosis, resulting in tumorigenesis. It was reported that the YAP is strongly elevated in multiple types of human malignancies such as breast, lung, small intestine, colon, and liver cancers. Recent work indicates that, surprisingly, Hippo signaling components' (SAV1, MST1/2, Lats1/2) mutations are virtually absent in human cancer, rendering this signaling an unlikely candidate to explain the vigorous activation of the YAP in most, if not all human tumors and an activated YAP promotes the resistance to RAF-, MAPK/ERK Kinase (MEK)-, and Epidermal growth factor receptor (EGFR)-targeted inhibitor therapy. The analysis of YAP expressions can facilitate the identification of patients who respond better to an anti-cancer drug treatment comprising RAF-, MEK-, and EGFR-targeted inhibitors. The prominence of YAP for those aspects of cancer biology denotes that these factors are ideal targets for the development of anti-cancer medications. Therefore, our report strongly indicates that the YAP is of potential prognostic utility and druggability in various human cancers.

• 한국축산식품학회지
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• 제43권6호
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• pp.1017-1030
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• 2023

Fetal bovine serum (FBS), which contains various nutrients, comprises 20% of the growth medium for cell-cultivated meat. However, ethical, cost, and scientific issues, necesitates identification of alternatives. In this study, we investigated commercially manufactured serum-free media capable of culturing Hanwoo satellite cells (HWSCs) to identify constituent proliferation enhancing factors. Six different serum-free media were selected, and the HWSC proliferation rates in these serum-free media were compared with that of control medium supplemented with 20% FBS. Among the six media, cell proliferation rates were higher only in StemFlex^TM Medium (SF) and Mesenchymal Stem Cell Growth Medium DXF (MS) than in the control medium. SF and MS contain high fibroblast growth factor 2 (FGF2) concentrations, and we found upregulated FGF2 protein expression in cells cultured in SF or MS. Activation of the fibroblast growth factor receptor 1 (FGFR1)-mediated signaling pathway and stimulation of muscle satellite cell proliferation-related factors were confirmed by the presence of related biomarkers (FGFR1, FRS2, Raf1, ERK, p38, Pax7, and MyoD) as indicated by quantitative polymerase chain reaction, western blotting, and immunocytochemistry. Moreover, PD173074, an FGFR1 inhibitor suppressed cell proliferation in SF and MS and downregulated related biomarkers (FGFR1, FRS2, Raf1, and ERK). The promotion of cell proliferation in SF and MS was therefore attributed to FGF2, which indicates that FGFR1 activation in muscle satellite cells may be a target for improving the efficiency of cell-cultivated meat production.

• Journal of Applied Biological Chemistry
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• 제62권3호
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• pp.275-280
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• 2019

약용식물 67종의 생리활성 부위를 대상으로 열수 추출물이 in vitro에서 xanthine oxidase의 활성에 미치는 효과를 확인하였다. 약용식물 중에서 황금, 지각, 하수오, 갈근, 청피, 복분자, 녹차 및 지실 추출물은 xanthine oxidase의 활성을 강력하게 저해하여 항통풍 천연소재로서의 활용 가능성이 높게 나타났다. 하수오 뿌리 추출물은 열과 pH에 대한 안정성이 우수하였고, 농도에 비례하여 xanthine oxidase의 활성을 저해하였다. 하수오 추출물은 2.0 mg/0.1 mL의 농도에서 xanthine oxidase에 대해 73.8%의 저해 효과를 나타내었다.