Effect of N~α-Terminal Acetyltransferase RimI on Human Prothymosin α Acetylation Expressed in Escherichia coli

Objective:To investigate the effect of RimI,one of the Nα-terminal acetyltransferases of E.coli,on human prothymosin α(ProTα) acetylation.Methods:The human ProTα and Nα-terminal acetyltransferase RimI were co-expressed in E.coli DH5α.To observe the level of N-terminal acetylation on human ProTα,ProTα was purified and detected by HPLC.Results:The ProTα was post-translational acetylated.Over-expression of RimI,long term induction and the cross-effect could affect the level of N-terminal acetylation of ProTα(P0.0001).The increasing N-terminal acetylated ProTα could be observed after inducing 6 h,whether RimI was over-expressed or not(P0.0001).There were 37.4% N-terminal acetylated ProTα in the presence of overdose RimI,64.3% N-terminal acetylated ProTα without of overdose RimI after inducing 12 h,and we could observe the inhibition after inducing 6 h(P=0.0007).Conclusion:The N-terminal acetylation of ProTα was inhibited when over-expressed Nα-terminal acetyltransferase RimI.