ABSTRACT
Objective To investigate the role of TRAF6 in NF-?B and AP-1 signaling pathway in human B cell line.Methods Human Ramos B cells were transfected with plasmids expressing YFP fusion dominant-negative TRAF6(DN-TRAF6),or transfected with shRNA-TRAF6 plasmid.After incubation overnight,cells were either sorted with flowcytometry or screened by G418.Activation of NF-?B and AP-1 pathway,including phosphorylation of I?B?,ERK,JNK and P38,as well as nuclear translocation of NF-?B subunits(P65,P50 and c-Rel)and AP-1 subunits(C-FOS,C-JUN,CREB and ATF) were detected by Western blot and ELISA.Results In cells which overexpress DN-TRAF6 or endogenous TRAF6 expression were knocked-down by shRNA,the phosphorylation of I?B?,as well as phosphorylation of JNK were inhibited.Furthermore,nuclear translocation of NF-?B subunits P65,P50,c-Rel,and AP-1 subunits C-FOS and C-JUN were also inhibited in B cells through overexpression of DN-TRAF6.Conclusion TRAF6 selectively activates some kinases in CD40 mediated NF-?B and AP-1 signaling pathway,and plays an important role in their activation.