Objective      To construct radixin (RDX) wild type and mutant over-expression vectors

pcDNA3.1-RDX WT

pcDNA3.1-RDX T564D

and pcDNA3.1-RDX T564A

and to study the effects of RDX phosphorylation on bile salt export pump (Bsep) expression of HepG2 cell membrane.        Methods      RDX wild type gene was used as template to carry out point mutation

T564D and T564A. All target DNAs were transferred to pcDNA3.1 to constru

ct 3 over-expression vectors

pcDNA3.1-RDX WT

pcDNA3.1-RDX T564D

and pcDNA3.1-RDX T564A. DH-5α competent cells were transformed with the recombinant plasmids for positive clone identification. Then target clones were used to transfect HepG2 cells and stable cell lines were established. Western blotting was used to confirm the expression of RDX

p-Thr564-RDX and Bsep.        Results      All the recombinant plasmids were correctly constructed. Western blot results demonstrated that the cell membrane Bsep expression was slightly higher in HepG2 cells transfected with pcDNA3.1-RDX WT than in the cells transfected with pcDNA-3.1-RDX T564A (

P

0.05) and significantly lower than in the cells transfected with pcDNA3.1-RDX T564D (

P

0.05).        Conclusion      RDX wild type and mutant over-expression vectors are successfully constructed. RDX phosphorylation improves Bsep expression on HepG2 cell membrane.