Construction of Eukaryotic Expression Vector of Human CC10 Gene and Expression of CC10 Protein in Lung Adenocarcinoma A549 Cell Line

Summary： A mammalian expression plasmid pcDNA3. 1-hCC10 was constructed and identified, then CC10 protein expression in A549 lung cancer cell line was detected. A 273 bp cDNA fragment was amplified from the total RNA of normal lung tissue by using RT-PCR and cloned into expression plasmid cDNA3. 1, and the recombinant plasmid was identified by employing double digestion restriction enzymes HindⅢ and BanH 1 and the cDNA sequence was assayed by the Sanger dideoxymediated chain termination method. The segment was then transfected into the A549 lung cancer cell line. The protein expression of CC10 was detected by immunofluorescence and Western blot. Our results showed that the cDNA fragment included the entire coding region （273 bp）. The re combinant eukaryotic cell expression vector of pcDNA3. 1-hCC10 was successfully constructed, and the sequence of the insert was identical to the published sequence. A549 cells line transfected with the pcDNA3. 1-hCC10 expressed high level of CC10 protein. The recombinant plasmid cDNA3. 1- hCC10 may serve as an effecnve tool for the study of tumorogenesis and tumor treatment.     

Construction of Tissue Plasminogen Activator （t-PA） of Eukaryotic Expressing Vector^伙

We construct eukaryotic expressing vector of tissue plasminogen activator （t-PA）. The t-PA cDNA was amplified by PCR techniques, The plasmid PETPFR containing t-PA cDNA was used as the templete of PCR, The PCR fragment of t-PA was digested with Hind Ⅲ and Sal. pcDNA3 was digested with Hind Ⅲ and Xho. The fragments oft-PA and pcDNA3 were linked in vitro. The recombinant was transformed into the competent JM109 bacteria and was selected by enzymes digestion and was confirmed by sequencing.     

Construction of eukaryotic expression vector encoding ATP synthase lipid-binding protein-like protein gene of Sj and its expression in HeLa cells

Objective： To clone and construct the recombinant plasmid containing ATP synthase lipid-binding protein-like protein gene of Schistosomajaponicum,（SjAslp） and transfer it into mammalian cells to express the objective protein. Methods： By polymerase chain reaction （PCR） technique, SjAslp was amplified from the constructed recombinant plasmid pBCSK＋/SjAslp, and inserted into cloning vector pUCm-T. Then, SjAslp was subcloned into an eukaryotic expression vector pcDNA3.1（＋）. After identifying it by PCR, restrictive enzymes digestion and DNA sequencing, the recombinant plasmid was transfected into HeLa cells using electroporation, and the expression of the recombinant protein was analyzed by immunocytochemical assay. Results： The specific gene fragment of 558 bp was successfully amplified. The DNA vaccine of SjAslp was successfully constructed. Immunocytochemical assay showed that SjAslp was expressed in the cytoplasm of HeLa cells. Conclusion： SjAslp gene can be expressed in eukaryotic system, which lays the foundation for development of the SjAslp DNA vaccine against schitosomiasis.     

Construction and identification of eukaryotic eukaryotic expression plasmid pcdna3.1-bace and its transient expression in cells

Objective： To generate eukaryotic expression vector of pcDNA3.1-BACE and obtain its transient expression in COS-7 cells and high expression in the neuroblastoma SK-N-SH cells. Methods： A 1503 bp cDNA fragment was amplified from the total RNA of human neuroblastoma by RT-PCR method and cloned into plasmid pcDNA3.1. The vector was identified by digestion with restriction enzymes BamHI and XhoI and sequenced by Sanger-dideoxy：mediated chain termination. The expression of BACE gene was detected by immunocytochemistry method. Results： The results showed that the cDNA fragment included 1503 bp total coding region. The recombinant eukaryotic cell expression vector of pcDNA3.1-BACE was constructed successfully, and the sequence of insert was identical to the published sequence. The COS-7 cells and the neuroblastoma SK-N-SH cells transfected with the pcDNA3.1-BACE plasmid expressed high level of BACE protein in cytoplasm. Conclusion： The recombinant plasmid pcDNA3.1-BACE can provide very useful tool for researching the mason of Alzheimer＇s disease and lays the important foundation for preventing the AD laterly.     

Construction of Prokaryotic Expression Plasmid of Fusion Protein Including Porin A and Porin B of Neisseria Gonorrhoeae and Its Expression in E. coli

In order to provide a rational research basis for clinical detection and genetic engineering vaccine, plasmid pET-28a ( ) encoding both Porin gene PIA and PIB of Neisseria gonorrhoeae was constructed and a fusion protein in E. coli DE3 expressed. The fragments of PIA and PIB gene of Neisseria gonorrhoeae were amplified and cloned into prokaryotic expression plasmid pET-28a ( ) with double restriction endonuclease cut to construct recombinant pET-PIB-PIA. The recombinant was verified with restriction endonuclease and sequenced and transformed into E. coli DE3 to express the fusion protein PIB-PIA after induced with IPTG. The results showed PIA-PIB fusion DNA fragment was proved correct through sequencing. A 67 kD (1 kD=0. 992 1 ku) fusion protein had been detected by SDS-PAGE. It was concluded that the fusion protein was successively expressed.     

Construction of Prokaryotic Expression Plasmid of mtrC Protein of Neisseria gonorrhoeae and Its Expression in E. Coli

Summary： In order to provide a rational research basis for detection of resistance of Neisseria gonorrhoeae to antimierobial hydrophobie agents and study on the resistant mechanism of multiple transferable resistance （mtr） efflux system, plasmid pET-28a（＋） encoding mtrC gene was constructed and the related target protein was expressed in Escherichia colt （E. cold DE3. The fragments of mtrC gene of Neisseria gonorrhoeae from the standard strains were amplified and cloned into prokaryotic expression plasmid pET-28a（＋） with restriction endonuelease to construct recombinant pET-mtrC which was verified by restriction endonuelease and DNA sequencing. The recom- binant was transformed into E. coli DE3 to express the protein mtrC induced by IPTG. The results showed mtrC DNA fragment was proved correct through restriction endonuelease and DNA sequencing. hs sequence was 99.5 % homologus to that published on GeneBank （U14993）. A 48.5 kD fusion protein which was induced by IPTG was detected by SDS-PAGE. It was concluded that the construction of prokaryotic expression plasmid of mtrC protein of Neisseria gonorrhoeae was correct and the fusion protein was successively expressed in E. coli.     

Cloning and expression of the ureC geneo f H.pylori

AIM: To express Hp ureC gene in E.coli, a fragment from Hp ureC was amplified by the polymerase chain reaction and was cloned into E.coli expressing plasmid vector--- pBV220. This study lay the foundation for further studies of its functions. METHODS : An 1173bp gene fragment was amplified by the polymerase chain reaction. The template DNA was purified from Hp clinical strain. The gene fragment was digested by BamH I and EcoR I and cloned into pGEM-3Zf (-) plasmid. Its sequence was determined by autosequencing instrument from two directions. Then the gene fragment was cloned into pBV220. Subsequently the DH5 a was transformed by pBV220/ureC and was induced by heat when temperature reached 42“C. The form of expressed protein was analyzed to learn that in which form the recombinant protein was expressed. The thin layer chromatogram was used to scan thegel to learn that the quantity of the expressed protein. Antigenicity of the expressed protein wasconfirmed by ELISA and DIGFA. RESULTS z 95% of the DNA sequence we got is the same as that ofHp strain M60398. A Mr 44000 recombinant protein was induced by heat when temperature reached 42℃. The molecular mass of the expressed ureC gene is coincide with expected. The expressed proteinaccounts for 24.8% of the whole protein of the host bactria. Although most of the recombinant proteinsare inclusion bodies in host bactria after translation, there does exist certain quantity of solvable proteins in the supernatant of bacteria lysate. CONCLUSION：Recombinant H.pylori urease C protein is expressed in E.coli and the expressed protein has the antigenicity ofureC. Our study lays the foundation for further studies of the functions of lip ureC.     

Construction of Prokaryotic Expressing Vector of Antisense Nucleic Acid of lasR and Its Effect on the Virulence of Pseudomonas Aeruginosus

To construct a pUCP18/lasRantisense plasmid carrying the reversed gene and analyze its effect on the virulence of Pseudomonas aeruginosus,LasR gene was amplified from the genome of Pseudomonas aeruginosus by PCR and reversely recombined with plasmid pUCP18.The recombi-nant pUCP18/lasRantisense was verified by enzyme digestion,PCR and sequencing.The biological ef-fects of pUCP18/lasRantisense were examined by using RT-PCR,NAD method and the assay of pyo-cyanin.Our results showed that the expected full length lasR fragment(721 bp) was extended from Pseudomonas aeruginosus gene with PCR.And it is consistent with LasR gene of Pseudomonas aeruginosa in GenBank(No.NC-002516).The recombinant plasmid was successfully constructed and transferred into Pseudomonas aeruginosus.The antisense nucleic acid of LasR gene could reduce the virulence of Pseudomonas aeruginosus and might serve as a new target site for treatment purpose.     

Prokaryotic expression of Chinese bovine enterokinase catalytic subunit

Background To express in vitro the bovine enterokinase catalytic subunit (EKL) protein, which could be used in the future for the cleavage and purification of fusion proteins.Methods Bovine enterokinase catalytic subunit cDNA was obtained by RT-PCR from the duodenal mucosa of a bovine obtained at a wholesale market, and then cloned into a pUCmT cloning vector and sequenced. The desired gene fragment was inserted into a pET39b expression plasmid and the recombinant vector pET39b-EKL was transformed into E. coli BL21 (DE3). Protein expression was induced using IPTG. The recombinant DsbA-EKL was purified with His·Tag affinity chromatography, and its bioactivity was analyzed.Results Compared with the sequence deposited in GenBank, the sequence of the EKL gene cloned in the present study is correct. It was also confirmed that the nucleotide sequence of expression plasmid pET39b-EKL was correct at the conjunction site between the recombinant DNA 5’terminal multi-cloning site and the recombinant fragment. SDS-PAGE analysis indicated that the target product was about 65 kDa and represented 28% of total cell protein. Purified recombinant protein was obtained by metal chelating chromatography using a Ni-IDA resin. After desalting and changing the buffer, the crude kinase was incubated at 21℃ overnight and shown to have a high autocatalytic cleavage activity.Conclusion The EKL gene from a Chinese bovine has been cloned successfully and expressed. This investigation has layed the foundation for future enterokinase activity research and for further large-scale application of expression products.     

Cloning of NHE-1 gene fragment from human lung can.cer cells and construction of its antisense expression vector

Objective: To clone the partial sequence of Na^ /H^ exchanger- 1 (NHE- 1) gene of human lung cancer cells and insert it reversely into the multiclone site of pLXSN in order to construct an antisense expression vector for tumor gene therapy it~ vivo. Methods: With use of the upstream and downstream primers containing Barn H I and EcoR I in their 5‘ ends respectively, a partial sequence of the first exon of NHE-1 gene was cloned in a length of 454 bp from genomic DNA of human lung cancer cell A549 with PCR method. The product was then direetionally and reversely insert into the multiclone site of pLXSN. Finally, the constructed recombinant was identified with agarose gel electrophoresis and DNA sequencing. Results: The cloned fragment was 461 bp in length and successfully ligated to pLXSN with the identification by agarose gel etectrophoresis. DNA sequencing confirmed that the fragment cloned and inserted into the vector was identical with the targeted one. Conclusion: The targeted fragment is successfully cloned and reversely inserted into pLXSN in our experiment. The antisense expression vector of NHE-1, pNHE-1, was constructed successfully.     

Construction and identification of a yeast two-hybrid bait vector and its effect on the growth of yeast cells and the self-activating function of reporter genes for screening of HPV18 E6-interacting protein

By using a yeast two-hybrid system,a yeast two-hybrid bait vector was constructed and identified for screening of the HPV18 E6-interacting proteins,and its effects on the growth of yeast cells and the activation of reporter genes were investigated.Total mRNA extracted from Hela cells was reversely transcribed into cDNA.Fragment of HPV18 E6 cDNA was amplified using RT-PCR and directly ligated to the pGBKT7 vector.The recombinant plasmid was confirmed by restriction endonuclease analysis and DNA sequencing.Th...     

Construtcion of Neisseria Gonorrhoeae Porin B Plasmid Recombinant and Its Expression in E. coli

A prokaryotic expression recombinant plasmid pET-PIB to express porin B (PIB) of Neisseria gonorrhoeae in E. coli DE3 was constructed in order to provide a basis of research in detection, prophylactic and therapeutic vaccine against the pathogen infection. The gene encoding PIB was amplified by PCR from Neisseria gonorrhoeae and cloned into prokaryotic expression plasmid pET-28a( ) to construct a pET-PIB recombinant, which was verified by restriction endonuclease and DNA sequencing. Protein PIB was expressed in E. coli DE3 induced with IPTG. The antigenicity of the expressed protein was evaluated by indirect ELISA. Rabbits were immunized with the protein and serum was collected after immunization. To assess the immunogenicity of the protein, the titer of serum to protein PIB was determined by ELISA. DNA sequence analysis showed that the nucleic acid sequence of PIB gene was 99.28 % of homology compared with that (NGPIB18) published in GenBank. A 41 kD fused protein was detected by SDS-PAGE and was proven to have reactivity with anti-PIB polyclonal antibody from mouse. A polyclonal antibody to PIB of 1：4000 titer determined by indirect ELISA was obtained from rabbit immunized with the purified product. Recombinant plasmid encoding PIB of Neisseria gonorrhoeae was constructed. Protein PIB with antigenicity and immunogenicity was successfully expressed.     

Construction of recombinant adeno-associated virus vector co-expressing hVEGF_(165) and hBMP_7 gene

Objective: To construct recombinant adeno-associated virus co-expressing human vascular epithelial growth factor 165(hVEGF165) and bone morphogenetic protein 7(hBMP7),measure the virus titer and verify the recombination. Methods:The AAV helper-free system was used as basis to generate recombinant AAV. The IRES sequence of plasmid pIRES was cut down and subcloned into ITR/MCS containing vector pAAV-MCS to construct recombinant plasmid pAAV-MCSa-IRES-MCSb. The hVEGF165 and hBMP7 gene was amplified by PCR and inserted into upstream MCSa and downstream MCSb respectively. Then,recombinant plasmid pAAV-hVEGF165-IRES-hBMP7,pAAV-RC and pHelper were co-transfected into AAV-293 cells to complete rAAV-hVEGF165-IRES-hBMP7 packaging. The GFP labeled rAAV-IRES-GFP was simultaneously packaged by using the parallel plasmid pAAV-IRES-hrGFP. The efficiency of AAV packaging was monitored under fluorescent microscope and recombinant viral particles were harvested from infected AAV-293 cells. The virus titer was measured by infecting AAV-HT1080 cells,and the recombinant AAV-hVEGF165-IRES-hBMP7 was verified by PCR of the exogenous interest genes. Results:Recombinant pAAV-hVEGF165-IRES-hBMP7 was verified by double digestion. GFP expression in AAV-293 could be observed under fluorescent microscope 72 h after transfection and the system provided a high packing ratio of 95%. The recombinant adeno-associated virus has a high titer of 5.5×1011vp/ml,and AAV-HT 1080 was infected at a ratio of 90%. The recombinant virus was confirmed by PCR of exogenous hBMP7 and hVEGF165 gene. Conclusion:Recombinant rAAV-hVEGF165-IRES-hBMP7 was successfully constructed with a high virus titer,which may offer foundation for in vitro and in vivo experiments of hVEGF165 and hBMP7 co-expression and provide a new method for gene therapy of bone regeneration.     

Construction of retrovirus vector with HBV Pol gene and its expression invitro

Objective: To construct retroviral vector with HBV Pol gene and study its expression in vitrn. Methods: The recombinant plasmid HBV2/pBR322 containing 2 copies of HBV full-length gene was provided as the amplification template. The PCR product was cloned into pMD 18-T and subeloned into pMSCVneo and pLNCX2 to construct the recombinantret roviral vectors with HBV Pol gene named by HBV P/pMSCVneo and HBV P/pLNCX2. HBV Pol gene was detected by RTPCR after transfecting the recombinant plasmids into SMMC7721 cells with liposome and G418 selection. Results: The retroviral vector with HBV Pol gene was successfully constructed and the expression of HBV Pol gene in vitro was detected by RTPCR. Conclusion: The retroviral vector with HBV Pol gene can be obtained, which will provide a new insight on the function of HBV Pol gene.     

Prokaryotic Expression and Biological Activity Analysis of Human Arresten Gene

To express recombinant arresten in Escherichia coli (E. Coli) and investigate its biological activity, prokaryotic expression vector of human arresten gene was constructed by gene engineering. Human arresten gene was amplified from recombinant plasmid pGEMArr by polymerase chain reaction (PCR), and inserted into prokaryotic expression vector pRSET containing T7 promoter. Restriction analysis and DNA sequencing verified that the arresten gene was correctly cloned into the expression vector. The recombinant plasmid pRSETAt was subsequently transformed into E. coli BL21 (DE3), and the target gene was expressed under induction of IPTG. SDS-PAGE analysis revealed that the recombinant protein with a molecular weight of 29 kD (1 kD=0. 992 1 ku) amounted to 29% of the total bacterial proteins. After purification and renaturation, the recombinant protein could significantly suppress the proliferation of human umbilical vein endothelial cells(HUVECs). These results suggested that the expression of a biologically active form of human arresten in the pRSET expression system laid a foundation for further study on the mechanistic insight into arresten action on angiogenesis and the development of powerful anti-cancer drugs.     

Construction and identification of recombinant lentivirus-mediated gene transfer system for rat transducer of regulated CREB activity 1

Objective:To construct a recombinant lentivirus vector which carries SD rat transducer of regulated CREB activity-1(TORC1) gene and examine its ability to express the TORC1 gene in vitro.Methods:The coding sequence of SD rat TORC1 gene was amplified using PCR and cloned into pGC-FU vector.293T cells were transfected using Lipofectamine 2000 and packaged for the recombinant lentivirus particles.When the cloned sequence was identified to be right,the recombinant lentivirus particles were amplified in a large quantity.The titer of virus was determined by real-time PCR and the level of TORC1 expression was examined by Western blot. Results:The recombinant lentivirus vector carrying TORC1 was constructed successfully and could express TORC1 at a high level in 293T cells in vitro,and the titer determined by real-time PCR was 2×108 TU/ml.Conclusion:The recombinant lentivirus vector could express TORC1 gene at a high level,and was very helpful in the study of exploring the effect of TORC1 on spinal cord injury.