1.Construction and expression of vector encoding Sox2 with mutated SUMO accepter site
Zekun GUO ; Xianqiang WU ; Liran SHAN ; Zhen SONG
Journal of Cellular and Molecular Immunology 2009;25(11):967-969
AIM:To construct eukaryotic expression plasmids encoding Sox2 and Sox2 K247R and identify their expression and SUMOylation. METHODS: With gift plas-mid encoding Sox2 gene as a template, Sox2 K247R was obtained by overlapping extension PCR, followed by construction of pCMV-HA-Sox2 and pCMV-HA-Sox2 K247R. After enzyme digestion analysis and DNA sequencing, these two constructs were transfected or co-transfected with pC-MV-Myc-SUMO1 into 293 FT cells by lipofectin method. Western blot was employed to analyze expression and SUMO ylation of Sox2. RESULTS: It was revealed that eukaryotic expression vectors were constructed with correct sequence, where in mutant Sox2, the AAG codon was switched to CGG codon. Western blot results showed that good expression of both wt and mut Sox2, of which the latter could not be modified by SUMO1. CONCLUSION: Successful construction and expression of Sox2 and Sox2 K247R. Sox2 could be SUMO lyated in vitro but Sox2 K247R not.
2.Low-dose radiation in the hip digital tomosynthesis
Huizhao WU ; Wenjuan WU ; Yan SONG ; Junli LU ; Zhe GUO ; Zekun ZHANG
Chinese Journal of Radiological Medicine and Protection 2015;35(2):153-156
Objective To explore the optimal dose ratio set in the hip digital tomosynthesis (DTS),and to reduce patient's examination dose as low as possible.Methods Ninety patients who received hip DTS examination were randomly divided into 3 groups,with the dose ratio as 6,7 and 8,respectively.One-way ANOVA test was used to compare.the image quality and radiation dose among 3 groups.Results The values of entrance surface dose (ESD),dose-area product (DAP) and image quality score of 3 groups were [(3.76 ± 1.89) mGy,(18.41 ± 11.71) dGy·cm2,3.03 ± 0.24],[(5.24±2.76)mGy,(26.99±13.34)dGy·cm2),3.60±0.11],and [(6.39±1.75)mGy,(36.96± 22.49) dGy· cm2,3.64 ± 0.09],respectively.The difference among three groups was statistically significant (F =10.94,9.45,139.26,P < 0.05).The S-N-K test showed that both ESD values and DAP values in 6,7,and 8 time-dose ratio group was from small to large.The image quality score of 6 time-dose ratio group was lower than that of the other groups with no significant difference.Conclusions Dose ratio is one of the important parameters to result in the radiation dose of DTS.Dose ration 7 is optimal in hip DTS,which could match the image quality and radiation dose best and finally protect patients from unnecessary radiation damage.
3.Expression, purification, and bio-activity analysis of fusion protein HBx-EGFP-TLM.
Xiaoyan SHI ; Yingying ZHANG ; Xiaowei ZHOU ; Jiansheng LU ; Zekun GUO ; Peitang HUANG
Chinese Journal of Biotechnology 2011;27(9):1371-1378
Hepatitis B virus X protein (HBx) has various functions and plays a crucial role in the development of hepatocellular carcinoma (HCC). However, due to different transfection efficiency levels and experimental approaches, it is difficult to correlate the exact functions of HBx to HBV-associated HCC. In this study, we constructed two prokaryotic expression vectors, pGEX-HBx-EGFP-TLM and pGEX-EGFP-TLM, which expressed HBx-EGFP-TLM and EGFP-TLM fusion proteins respectively. Both vectors contained a coding sequence of TLM transduction motif derived from the PreS2-domain of Hepatitis B Virus surface antigens. In addition, EGFP was expressed as a reporter reflecting the transduction efficiency of TLM. The fusion protein HBx-EGFP-TLM or EGFP-TLM purified from Escherichia coli BL21(DE3) by AKTA Purifier system was incubated with AML12 and SMMC-7721 cells. Both Western blotting and laser confocal results indicated that the translocation motif TLM could lead HBx-EGFP and EGFP into the cytoplasm. Dual-Luciferase Reporter Assay revealed that the activity of mEZH2 promoter could be up-regulated by the recombinant HBx. In conclusion, we expressed a cell-permeable HBx, which could provide a new method to study the functions of HBx.
Amino Acid Motifs
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genetics
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Cell-Penetrating Peptides
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biosynthesis
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genetics
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Escherichia coli
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genetics
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metabolism
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Genetic Vectors
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genetics
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Green Fluorescent Proteins
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biosynthesis
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genetics
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Hepatitis B Surface Antigens
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genetics
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Protein Precursors
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genetics
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Recombinant Fusion Proteins
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biosynthesis
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genetics
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isolation & purification
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Trans-Activators
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biosynthesis
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genetics