ABSTRACT
The discovery of hydroxylases in the anticancer drug taxol biosynthesis pathway is a hotspot and difficulty in current research. In this study, a new hydroxylase gene TcCYP725A22 (GenBank accession number: MF448646.1) was used to construct a sub-cellular localization vector pCAMIBA1303-TcCYP725A22-EGFP to get the transient expression in onion epidermal cells. Laser confocal microscopy revealed that the protein encoded by this gene was localized in the cell membrane. Furthermore, the recombinant plant expression plasmid pBI121-TcCYP725A22 was constructed. After transient transformation to the Taxus chinensis mediated by Agrobacterium tumefaciens LBA4404, qRT-PCR and LC-MS were utilized to analyze the effects of TcCYP725A22 overexpression on the synthesis of taxol. The results showed that, in the TcCYP725A22 overexpressed cell line, expression levels of most defined hydroxylase genes for taxol biosynthesis were increased, and the yield of taxanes were also increased. It was concluded that the hydroxylase gene TcCYP725A22 is likely involved in the biosynthetic pathway of taxol.
Subject(s)
Biosynthetic Pathways , Mixed Function Oxygenases , Paclitaxel , Taxoids , TaxusABSTRACT
Objective To investigate expression of PP2CE in human hepatocellular carcinoma(HCC)tissues and the clinical pathological significance,and test its sub-cellular localization in liver cells and HCC cells.Methods A total of 50 samples of HCC tissues and their para-carcinoma tissues were collected in Tongji Hospital(Wuhan).PP2CE mRNA and protein levels were detected in HCC tissues and their para-carcinoma tissues by qRT-PCR and immunohistochemistry method.Immunofluorescent assay was performed to test the sub-cellular localization of PP2CE in the cells.Results PP2CE mRNA and protein expression levels were significantly decreased in HCC tissues as compared with those in para-carcinoma tissues(both P＜0.05).Immunohistochemistry analysis found that PP2CE expression was associated with tumor size,differentiated degree,portal vein invasion and clinical stage(both P＜0.05).Immunofluorescent assay suggested that PP2CE was mainly located in the cytoplasm and perinuclear area.Conclusion PP2CE is reduced in HCC and may be implicated in the development and progression of HCC.
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Objective To construct mycobacterial membrane-anchored expression vector and to analyze expression level and sub-cellualr localization of exogenous target protein. Methods Based on the mycobacterial intracellular expression vector pMFA42 which contained a strong promoter of pfurAma mutant, the signal sequence of Mycobacterium tuberculosis(Mtb) 19×103 lipoprotein (19SS) was synthesized and was then cloned into the downstream of pfurAma mutant to generate the mycobacterial membrane-anchored expression vector pMFA42M. The coding gene of enhanced green fluorescent protein(EGFP) was amplified by PCR, and then sub-cloned into these two vectors described above to construct recombinant EGFP fused and membrane-anchored strains, respectively. The coding genes of Mtb immuno-dominant antigens Ag85A and its chimera Ag856A2 were then sub-cloned intothe membrane-anchored construct pMFA42MG to produce recombinant Mtb antigen EGFP fused-expression strains. After that, expression levels and sub-cellualr localization of exogenous target protein were further analyzed by Western blot and flow cytometry sorting(FCS), and the fluorescence intensities of recombinant EGFP- expressed strains were observed in vitro directly and after transfection of murine macrophage cell line RAW264.7. Results The novel mycobacterial membrane-anchored expression vector was constructed successfully by introduction of signal sequence of Mtb 19×103 lipoprotein. Using of EGFP as model antigen, exogenous target protein was demonstrated to be expressed with high level and could be anchored into cell membrane of recombinant mycobaterial strains. Conclusion A novel mycobacterial membrane-anchored expression vector was constructed successfully to research recombinant BCG and functions of mycobacterial membrane proteins, and the constructed EGFP-expressed recombinant strains could also be used to research cytophagy in cell model and mycobacterial colony and translocation in animal immunization as model indicator bacteria.
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APOBEC(apolipoprotein B mRNA-editing enzyme catalytic-polypeptide) family members were reported as innate immune molecules with anti-viral activity for many viruses, such as HIV and HBV.In order to understand the function of APOBEC, the APOBEC-3F and-3G were cloned, expressed, and the sub-cellular localization of them was detected.The genes of APBEC-3F and-3G were cloned from PHA-stimulated PMBC and expressed in the MDCK cell by transfection.The sub-cellular localization of APOBEC-3F and-3G were detected by immunofluorescence.APOBEC-3F and-3G were cloned by RT-PCR and confirmed by DNA sequencing.The immunofluorescence indicated APOBEC-3F and-3G were located in the cytosal.APOBEC-3F and-3G could inhibit HBV replication effectively in HepG2.2.15 cell.APOBEC-3F and-3G could not be trans-located into nuclear by nuclear location signal(NLS) or bi-NLS(B-NLS).These results will help the future research on the function of APOBEC.