• 제목/요약/키워드: expression vectors

검색결과 393건 처리시간 0.027초

Effect of IRES Controlled Reporter Gene on Screening and Production of Recombinant Human EPO Proteins from Cultured CHO Cells

  • Lee Hyun Gi;Park Jin-Ki;Kim Sung-Woo;Ko Eun-Mi;Kim Byoung-Ju;Jo Su-Jin;Byun Sung-June;Yang Boh-Suk;Chang Won-Kyong;Lee Hoon-Taek;Lee Poong-Yeon
    • Reproductive and Developmental Biology
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    • 제30권2호
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    • pp.81-85
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    • 2006
  • This study was conducted to examine the effect of IRES controlled reporter gene on screening and production of recombinant human erythropoietin (EPO) proteins from cultured CHO cells. The cDNA was cloned for EPO from human liver cDNA Using site-directed mutagenesis, we generated recombinant human EPO (rhEPO) with two additional N-glycosylations (Novel erythropoiesis-stimulating protein: NESP). Wild type hEPO and NESP were cloned into expression vectors with GFP reporter gene under regulatory control of CMV promoter and IRES so that the vectors could express both rhEPO and GFP. The expression vectors were transfected to cultured CHO-K1 cells. Under microscopy, expression of GFP was visible. Using supernatant of the culture, ELISA assay, immunocytochemistry and in vitro assay using EPO dependant cell line were performed to estimate biological activity to compare the production characteristics (secretion levels, etc.) between rhEPO and NESP. The activity of NESP protein, obtained by mutagenesis, was described and compared with its rhEPO counterpart produced under same conditions. Although NESP had less secretion level in CHO cell line, the biological activity of NESP was greater than that of rhEPO. These results are consistent with previous researches. We also demonstrated that rhEPO and GFP proteins expressed simultaneously from transfected CHO cell line. Therefore we conclude that use of GFP reporter gene under IRES control could be used to screen and produce rhEPO in cultured CHO cells.

Inhibition of HBV replication and gene expression in vitro and in vivo with a single AAV vector delivering two shRNA molecules

  • Li, Zhi;He, Ming-Liang;Yao, Hong;Dong, Qing-Ming;Chen, Yang-Chao;Chan, Chu-Yan;Zheng, Bo-Jian;Yuen, Kwok-Yung;Peng, Ying;Sun, Qiang;Yang, Xiao;Lin, Marie C.;Sung, Joseph J.Y.;Kung, Hsiang-Fu
    • BMB Reports
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    • 제42권1호
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    • pp.59-64
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    • 2009
  • Hepatitis B virus (HBV) infection is highly prevalent worldwide. The major challenge for current antiviral treatment is the elevated drug resistance that occurs via rapid viral mutagenesis. In this study, we developed AAV vectors to simultaneously deliver two or three shRNAs targeting different HBV-related genes. These vectors showed markedly better antiviral effects than ones that delivered a single shRNA in vitro. A dual shRNA expression vector (AAV-157i/1694i), which simultaneously expressed two shRNAs targeted the S and X genes of HBV, reduced HBsAg, HBeAg and HBV DNA levels by $87{\pm}4$, $80.3{\pm}2.6$ and $86.2{\pm}7%$ respectively, eight days post-transduction. In a mouse model of prophylactic treatment, HBsAg and HBeAg were reduced to undetectable levels and the serum HBV DNA level was reduced by at least 100 fold. These results indicate that AAV-157i/1694i generates potent anti-HBV effects and that the strategy of constructing multi-shRNA expression vectors may lead to enhanced anti-HBV efficacy and overcome the evading mechanism of the virus and thus the development of drug resistance.

Expression and Purification of Human Farnesoid X Receptor-Ligand Binding Domain as Soluble Form Using a Dual Cistronic Expression Vector

  • Kang, Hyun;Ye, Micheal B.;Bahk, Young Yil
    • Journal of Microbiology and Biotechnology
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    • 제23권3호
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    • pp.322-328
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    • 2013
  • In this study, we show the expression and purification of the human recombinant farnesoid X receptor (FXR)- ligand binding domain (LBD) protein in E. coli using a double cistronic vector, pACYCDuet-1, as a soluble form. We describe here the expression and characterization of a biologically active $FXR-LBD_{(248-476)}$. When expressed in the influence of bacterial promoters ($P_{T7}$ and $P_{Tac}$) of the single cistronic expression vectors, the human recombinant $FXR-LBD_{(248-476)}$ was found to be totally insoluble. However, by using a double cistronic expression vector, we were able to obtain the human recombinant $FXR-LBD_{(248-476)}$ in a soluble form. To allow for biological activities, we have subcloned into the pACYCDuet-1 vector, expressed in E. coli cells at some optimized conditions, and purified and characterized the human recombinant active $FXR-LBD_{(248-476)}$ proteins using the fluorescence polarization assay. This suggests that the expression of FXR-LBD in a double cistronic vector improves its solubility and probably assists its correct folding for the biologically active form of the proteins. We suggest that this may represent a new approach to high expression of other nuclear receptors and may be useful as well for other classes of heterodimeric protein partners.

Expression of the EPO-like Domains of Human Thrombopoietin in Escherichia coli

  • Koh, Yeo-Wook;Koo, Tai-Young;Ju, Sang-Myoung;Kwon, Chang-Hyuk;Chung, Joo-Young;Park, Myung-Hwan;Yang, Jai-Myung;Park, Seung-Kook
    • Journal of Microbiology and Biotechnology
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    • 제8권6호
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    • pp.553-559
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    • 1998
  • cDNA of human thrombopoietin (hTPO) amplified by polymerase chain reaction from a cDNA library of human fetal liver was cloned. EPO-like domains ($hTPO_{153} \;or\; hTPO_{l63})\; of\; hTPO(hTPO_{332}$) were expressed in Escherichin coli using several kinds of expression systems, such as ompA secretion, thioredoxin fusion, and the $P_L$ and T7 expression systems. To obtain $hTPO_{153}$ in soluble form, $hTPO_{153}$ cDNA was fused in-frame behind the gene encoding ompA signal sequence and thioredoxin protein. When fused with either of the genes, $hTPO_{153}$ was not expressed to the detectable level. However, a high level expression of the EPO-like domain of hTPO was obtained using the PL and T7 expression system. $hTPO_{153} \;or\; hTPO_{l63} cDNA were subcloned into the pLex and pET-28a(+) vectors under the control of the inducible$ P_L\;T_7$ promoter, respectively. Proteins expressed using pl.ex vector and pET-28a(+) detected in insoluble forms with an expression level of about 14% and 9% of total cellular proteins, respectively, and the level of expression was rapidly diminished in 2 h after the maximum level of expression was reached.

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Interactions between Filamin A and MMP-9 Regulate Proliferation and Invasion in Renal Cell Carcinoma

  • Sun, Guo-Gui;Wei, Cui-Da;Jing, Shao-Wu;Hu, Wan-Ning
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3789-3795
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    • 2014
  • This study aimed to analyze the expression, clinical significance of filamin A (FLNA) in renal cell carcinoma (RCC) and biological effects in a cell line by regulating FLNA expression. Immunohistochemistry and Western blotting were used to analyze FLNA protein expression in 70 cases of RCC and normal tissues to study the relationship with clinical factors. FLNA lentiviral and empty vectors were transfected into RCC to study the influence of up-regulated expression of FLNA. FLNA siRNA was transiently transfected into ACHN kidney carcinoma cells by a liposome-mediated method and protein was detected by Western blotting. The level of expression was found to be significantly lower in RCC than normal tissues (p<0.05). No correlation was noted with gender, age, tumor size or pathological types (p>0.05), but links with lymph node metastasis, clinic stage and histological grade were noted (p<0.05). Loss of FLNA expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (p<0.05). Results for biological function showed that ACHN cells transfected with FLNA had a lower survival fraction, significant decrease in migration and invasion, higher cell apoptosis, higher percentage of the G0/G1 phases, and lower MMP-9 protein expression compared with ACHN cells untransfected with FLNA (p<0.05). However, renal 786-0 cells transfected with FLNA siRNA had a higher survival fraction, significant increase in migration and invasion, and higher MMP-9 protein expression compared (p<0.05). In conclusion, FLNA expression was decreased in RCC and correlated significantly with lymph node metastasis, clinic stage, histological grade and poor overall survival, suggesting that FLNA may play important roles as a a tumor suppressor in RCC by promoting degradation of MMP-9.

Pichia PGK1프로모터의 분석과 P. pastoris에 있어 외래단백질발현을 위한 Episomal벡터의 제조 (Deletion Analysis of Pichia PGK1 Promoter and Construction of an Episomal Vector for Heterologous Protein Expression in P. pastoris)

  • 이성재;홍인표;백선열;최신건
    • 한국미생물·생명공학회지
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    • 제35권3호
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    • pp.184-190
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    • 2007
  • 대략 2 kb의 크기를 가진 Pichia pastoris phosphoglycerate kinase gene (PGK1)의 프로모터부분을 266bp의 작은 크기로 최소화하여 P. pastoris에 있어 episomal의 새로운 항시적 발현벡터를 제조하였다. P. pastoris의 새로운 항시적 발현벡터를 개발하기 위하여 기존의 Pichia발현벡터인 pGABZB의 GAP프로모터부분을 연속적으로 일정 부분이 절단된 PGK1프로모터에 beta-galactosidase유전자가 결합된 부분으로 치환하였다. LacZ유전자를 reporter유전자로 사용하였을 때에 PGK1프로모터의 발현세기는 다른 항시적 프로모터인 GAP프로모터 보다는 낮았지만 TEF1프로모터 보다는 높았다. 본 논문에서 PGK1 프로모터의 불필요한 부분을 제거함으로서 Pichia에서 외래발현을 위한 새로운 episomal발현벡터인 pPGKZ-E를 제조하였으며 이 것은 P. pastoris에 있어 발현세기를 선택할 수 있는 발현벡터선택의 폭을 넓게 하였다.

Nuclear localization of Obox4 is dependent on its homeobox domain

  • Park, Geon Tae;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
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    • 제40권1호
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    • pp.1-6
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    • 2013
  • Objective: Oocyte-specific homeobox 4 (Obox4) is preferentially expressed in oocytes and plays an important role in the completion of meiosis of oocytes. However, the Obox4 expression pattern has not been reported yet. In this study, we investigated the subcellular localization of Obox4 using a green fluorescent protein (GFP) fusion expression system. Methods: Three regions of Obox4 were divided and fused to the GFP expression vector. The partly deleted homeodomain (HD) regions of Obox4 were also fused to the GFP expression vector. The recombinant vectors were transfected into HEK-293T cells plated onto coated glass coverslips. The transfected cells were stained with 4',6-diamidino-2-phenylindol and photographed using a fluorescence microscope. Results: Mutants containing the HD region as well as full-length Obox4 were clearly localized to the nucleus. In contrast, the other mutants of either the N-terminal or C-terminal region without HD had impaired nuclear localization. We also found that the N-terminal and C-terminal of the Obox HD contributed to nuclear localization and the entire HD was necessary for nuclear localization of Obox4. Conclusion: Based on the results of the present study, we demonstrated that the intact HD region of Obox4 is responsible for the nuclear localization of Obox4 protein in cells.