Abstract
Objective:To construct a human ether-a-go-go-related gene(HERG)nonsense mutant L539fs/47-*558W into the autonomously fluorescent,eukaryotic expression vector pEGFP-C2,and to verify expression of the reconstruct in human embryonic kidney-293(HEK293)cells.Methods:The mutational fragment was subcloned into pEGFP-C2-HERG by double digestion of Sbf Ⅰ,Eco91 Ⅰ and rejoining of T4 ligase.After verification,the recombinant pEGFP-C2-L539fs/47-*558W and pEGFP-C2-HERG were respectively transfected into HEK293 cells for 48 h by the Lipofect method to observe the expression location of the fusion protein by laser confocal imaging scanning in vivo.pcDNA3-L539fs/47-*558W and pcDNA3-HERG were transfected to observe the expression location of the HERG protein by immunofluoresceoce.The mutant protein size was determined by Western blotting.Results:The about 1 kb-sized mutation region cDNA fragment from pcDNA3-L539fs/47-* 558W and the about 7.2 kb-sized target vector fragment from pcDNA3-HERG were ligated after purification and gel recovery.pEGFP-C2-L539fs/47*-558W,approximately 8.2 kb,was demonstrated successfully been constructed under agarose gel electrophoresis and further sequencing.Laser confocal imaging showed that pEGFP-C2-HERG was mainly expressed in the membrane,whereas truncated mutant-type HERG in the pEGFP-C2 vector was partially located in the cytoplasm,the others were transported to the cell membrane in living HEK293 cells.The same as the immunofluoresceoce results after transfection of pcDNA3-HERG and pcDNA3-L539fs/47-558W.Wild-type HERG-GFP fusion protein expressed 160 and 180 kDa bands.The mutant and mutant-GFP fusion proteins were 70 and 100 kDa,respectively.Conclusion:pEGFP-C2-L539fs/47-*558W was successfully constructed by double digestion method GFP had no effect on its protein expression and trafficking in HEK293 cells,which laid a foundation for the further study on L539fs/47-*558W.