• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.131-137
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• 2001

Previous work has identified that only the catabolite responsive element A (creA; previously called cre-2) out of two potential cre sequences (cre-1: nucleotide +160 to +173 and cre-2: +173 to +186), recognized within the coding region of the xylanaseA gene (xynA) of Bacillus stearothermophilus No.236, was actually, was actually involved in the carbon catabolite repression(CCR) of xynA expression in B. subtilis. However, the level of CCR of xynA expression in the original B.stearothermophilus No.236 strain (70-fold repression). Therefore, to search for an additional cre element in the promoter region, the upstream region of the xynA gene was subcloned by chromosome walking, and as a result, another potential cre element (nucleotide -124∼-137; designated creB) was recognized in this region. The cre-like sequence revealed a high homology to the cre consensus sequence. The xylanase activity of B. subtilis MW15 bearing pWPBR14 (containing creA and creB) cultured in a medium containing xylose as the sole carbon source was about 7.7 times higher than that observed for the same culture containing glucose. B. subtilis MW15 bearing pWPBR23 (containing only creA) produced an activity about 2.4 times higher. This pattern of CCR was confirmed using derivatives of xynA::aprA fusion plasmids. Furthermore, a measurement of the amounts of the xynA transcript showed a similar pattern as that for the production of xylanase. In addition, the synthesis of xylanase in B. subtilis QB7115 [a catabolite control protein A (ccpA) mutant strain] carrying pWPBR14 was almost completely relieved from glucose repression. Together, these results lead to a conclusion that the CCR of the expression of the xynA gene is mediated by CcpA binding at creA and creB sites in B. subtilis.

• Laboraroty Animal Research
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• 제34권4호
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• pp.147-159
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• 2018

Genetically engineered mouse models are commonly preferred for studying the human disease due to genetic and pathophysiological similarities between mice and humans. In particular, Cre-loxP system is widely used as an integral experimental tool for generating the conditional. This system has enabled researchers to investigate genes of interest in a tissue/cell (spatial control) and/or time (temporal control) specific manner. A various tissue-specific Cre-driver mouse lines have been generated to date, and new Cre lines are still being developed. This review provides a brief overview of Cre-loxP system and a few commonly used promoters for expression of tissue-specific Cre recombinase. Also, we finally introduce some available links to the Web sites that provides detailed information about Cre mouse lines including their characterization.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.109-117
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• 2020

Cre recombinase is widely used to manipulate DNA sequences for both in vitro and in vivo research. Attachment of a trans-activator of transcription (TAT) sequence to Cre allows TAT-Cre to penetrate the cell membrane, and the addition of a nuclear localization signal (NLS) helps the enzyme to translocate into the nucleus. Since the yield of recombinant TAT-Cre is limited by formation of inclusion bodies, we hypothesized that the positively charged arginine-rich TAT sequence causes the inclusion body formation, whereas its neutralization by the addition of a negatively charged sequence improves solubility of the protein. To prove this, we neutralized the positively charged TAT sequence by proximally attaching a negatively charged poly-glutamate (E12) sequence. We found that the E12 tag improved the solubility and yield of E12-TAT-NLS-Cre (E12-TAT-Cre) compared with those of TAT-NLS-Cre (TAT-Cre) when expressed in E. coli. Furthermore, the growth of cells expressing E12-TAT-Cre was increased compared with that of the cells expressing TAT-Cre. Efficacy of the purified TAT-Cre was confirmed by a recombination test on a floxed plasmid in a cell-free system and 293 FT cells. Taken together, our results suggest that attachment of the E12 sequence to TAT-Cre improves its solubility during expression in E. coli (possibly by neutralizing the ionic-charge effects of the TAT sequence) and consequently increases the yield. This method can be applied to the production of transducible proteins for research and therapeutic purposes.

• Journal of Medicine and Life Science
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• 제20권2호
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• pp.67-72
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• 2023

Carbapenem-resistant Enterobacteriaceae (CRE) infections have increased rapidly over the past decade and are recognized as a severe health threat in Korea and worldwide. This study aimed to identify the status and characteristics of CRE infection in Jeju province and provide important basic data for the prevention and management of CRE infection. A descriptive epidemiological analysis was performed on reported cases of CRE infection in Jeju Province between 2018 and 2021 using the integrated management system for disease, an infectious disease reporting system from the Korea Disease Control and Prevention Agency. The annual difference and distribution trends of CRE infection were analyzed using CRE isolates, carbapenemase-producing CREs (CP-CRE) and their genotypes, and the type of medical institution in Jeju Province. CRE infections steadily increased in Jeju from 2018 to 2021, and the proportion of CP-CRE among the CREs also showed a statistically significant increase each year. Among the CRE isolates, Klebsiella pneumoniae (KPC, 62.13%) was the most common, and among the CP-CRE genotypes, KPC (81.62%) showed the highest distribution and increased each year. As the distribution of CP-CRE in have increased over the past 4 years, measures to prevent the spread and outbreak of CRE infections are warranted. The results of this study are expected to be used as basic data for prevention and management of CRE infections in the province.

• 대한의생명과학회지
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• 제30권3호
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• pp.101-112
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• 2024

This review provides an overview of carbapenem-resistant Enterobacterales (CRE) studies. CRE, called superbugs, has a high mortality rate and an increased resistance rate in several countries. The bacteria representing CRE are Klebsiella species and Escherichia spp., and they cause urinary tract infections (UTIs) and bloodstream infections (BSIs). CRE acquires resistance due to several mechanisms, typically divided into carbapenemase-producing (CP)-CRE and non-CP-CRE. Furthermore, although there are several antibiotics developed to treat CRE, they have their limitations; thus, antibiotic combination therapies or novel treatments are being developed. Therefore, since research on CRE and the use of appropriate antibiotics is important, some CRE-resistant mechanisms that enhance them are discussed. This review article was written using information obtained from Google Scholar and the National Center for Biotechnology Information website.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• 한국식품영양과학회지
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• 제45권1호
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• pp.76-83
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• 2016

본 연구는 커피를 추출한 후 발생되는 커피박을 식재료로 활용할 수 있는 방안을 모색하고자 커피박 첨가 형태를 달리하여 머핀을 제조하고 품질 특성을 검토하였다. 커피박 열수추출물(CRE) 머핀의 중량(62.01~62.36 g)은 대조구(61.64 g)에 비해 높았으며, 높이(6.03~6.23 cm)와 부피(186~493 mL)도 대조구(5.87 cm, 185 mL)에 비해 높았다. 수분 함량은 CRE 머핀(29.41~29.92%)과 커피박 분말(CRP) 머핀(30.10~31.11%)이 대조구에 비해 높았다. L(lightness) 값과 b(yellowness) 값은 CRE 및 CRP 첨가량이 증가할수록 감소하였으나 a(redness) 값은 증가하였다. CRE 머핀의 경도는 대조구에 비해 유의적으로 낮았으나, CRP 첨가구는 대조구보다 높았으며 첨가량이 증가할수록 증가하였다. 총 폴리페놀 함량은 CRE 및 CRP 머핀이 대조구보다 높았으며, 첨가량이 증가할수록 유의적으로 증가하였다(P<0.05). CRE 머핀의 DPPH 라디칼 소거능은 15.91~83.25%로 대조구(5.53%)에 비해 유의적으로 높았으며, 농도 증가에 비례하여 증가하였다. ABTS 라디칼 소거능도 CRE 첨가구(1.91~48.09%)가 대조구(25.20%)에 비해 유의적으로 높았으며, 농도가 증가함에 따라 유의적으로 증가하였다(P<0.05). 관능검사 결과 머핀 내부의 외관과 색, 풍미와 맛은 CRE 첨가구가 대조구보다 우수하였다. 맛과 종합적 기호도는 1.0% 첨가구가 가장 우수하였다. CRP 머핀의 외관과 내부 색은 1.0% 첨가구가 가장 우수하였으며, 풍미는 CRP 첨가구가 대조구보다 높았고 맛과 종합적 기호도는 1.0% 첨가구가 가장 우수하였다. 이상의 결과를 종합해 보면 항산화 활성이 다량 잔존하고 있는 커피박은 제과제빵의 항산화 활성 등 기능성 강화 소재로 활용이 가능하며, 머핀 이외에도 다양한 식품 산업에 활용이 가능할 것으로 판단된다.

• 한국차세대컴퓨팅학회논문지
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• 제13권5호
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• pp.104-112
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• 2017

3GPP에서는 HetNet에서 매크로셀과 스몰셀 간 송수신 전력 차이에 따른 트래픽 불균형을 완화하기 위해 업로드 자원이 더 효율적인 스몰셀을 선택하는 CRE (Cell Range Expansion)를 도입하였다. 그리고 이로 인한 신호 간섭 문제 해결을 위하여 ABS (Almost Blank Subframes) 방법이 제안되었다. 본 논문에서는 매크로셀 내의 스몰셀의 개수와 CRE로 확장된 지역에 위치한 단말, 매크로셀 단말의 비율에 따라 ABS 비율을 산출하는 방법을 제안한다. 제안한 방법을 LTESim 시뮬레이터상에 구현하여, 기존에 제안된 방법들과 성능을 비교하였다. 실혐 결과는, 제안된 방법이 기존 방법들과 비교하여 throughput 과 패킷 손실 성능을 향상시킴을 보여준다. 특히 성능 향상이 CRE 경계값에 의하여 달라짐을 보이고, 최적의 성능 개선을 구하기 위한 CRE 경계값이 존재함을 보인다.

• 한방안이비인후피부과학회지
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• 제22권2호
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• pp.50-59
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• 2009

Objectives : The aim of this study was conducted that CRE (Coptidis Rhizoma Extract) induces apoptosis in YD-10B cells, human oral squamous carcinoma cell line. Methods : In this study, YD-10B cells were exposed to CRE (0.03-0.30 mg/ml), for 6-24 hours. We measured the effects of CRE on the changes of cell viability and cell membrane, TUNEL assay of CRE-treated YD-10B cell. Results : In this study, CRE caused a decrease of viability in YD-10B cells, human oral squamous carcinoma cell line. When YD-10B cells were treated with CRE, cells showed dose-dependent manner apoptotic cell death. Conclusions : These results suggest that CRE may be potential therapeutic approach in the clinical management of oral squamous cell carcinoma.

• 한국식품영양과학회지
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• 제41권3호
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• pp.345-350
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• 2012

본 실험은 CRE 80% 에탄올 추출물을 식이에 0.5%, 1% 혼합하여 5주간 섭취시켰을 때 CRE 추출물이 SHR의 혈압에 미치는 영향을 확인함으로써 CRE 추출물이 고혈압 흰쥐의 지질성분과 혈압에 미치는 영향을 조사함으로써 CRE의 기능성식품으로서의 이용 가능성을 확인하였다. 실험기간 중 실험쥐의 일일평균 체중변화량은 0.5% CRE 보충군(II)은 1.63 g/day로 정상식이 급여군보다 일일평균 체중증가량이 유의적으로 감소하는 결과를 나타내었다. 간, 신장, 비장의 무게 변화를 측정한 결과 유의적인 차이를 나타내지 않았으며, 혈청 내 포도당 농도 또한 정상식이 급여군에 비해서 0.5%, 1% CRE 추가 보충군이 감소하는 경향은 보였으나 유의적인 차이는 나타나지 않았다. 본 실험에서 총 cholesterol 함량은 정상식이 급여군보다 0.5%, 1% CRE 보충 급여군에서 유의적으로 증가하는 경향을 보였지만 HTR을 확인한 결과 정상식이 급여군보다 0.5%, 1% CRE 보충 급여군이 각각 11% 증가한 결과를 나타냈기 때문에 혈중 총 cholesterol 함량의 증가는 HDL-cholesterol의 농도 증가에 의한 것으로 생각된다. HDL-cholesterol 농도는 정상식이 급여군과 0.5%, 1% CRE 보충 급여군 모두에서 유의적으로 증가하는 경향을 나타냈다. LDL-cholesterol 역시 유의적으로 증가하는 경향을 나타냈지만 HDL-cholesterol/LDL-cholesterol의 증가 비율로 봤을 때 HDL-cholesterol이 정상식이 급여군보다 0.5% CRE 보충 급여군이 15%, 1% CRE 보충급여군이 36.5%로 유의적으로 증가하는 결과를 나타냈다. 실험기간 동안 SHR의 혈압 변화는 정상식이 급여군(I)의 경우 거의 일정하게 혈압이 유지되는 경향을 보이다가 5주차에는 다시 증가한 반면 CRE 0.5% 보충군(II)은 초기혈압에서 떨어지는 경향을 보이다가 2주째에 혈압이 다시 상승했다. 하지만 그 후 다시 감소하는 경향을 보였고, CRE 1% 보충군(III)은 일정하게 혈압이 감소하는 경향을 나타냈다. 따라서 CRE 추출물이 SHR의 혈압을 낮추고 지질대사 개선에 영향을 주어 혈관계 장애로 인해 발병되는 고혈압, 당뇨, 뇌혈관질환, 동맥경화증과 같은 질환을 예방하는 기능성식품으로서 이용 가능성이 기대된다.