Abstract: Objective To investigate the role of Rer1 in hERG potassium channel protein transport,and to study the medicine Baf A1 that may restore abnormal hERG transport. Methods HEK293T cells were transiently transfected with constructed A561V mutant and WT plasmids, the wild-type,mutant and mixed transfection cell models were established.The expressions of hERG and Rer1 were detected by immunofluorescence and Western blot.siRNA was used to knockdown the expression of Rer1 and detect the expression of hERG;Bafilomycin A1,a V-ATPase inhibitor was incubated with 1 mmol/L for 6 hours.Western blot was used to detect the changes of hERG protein before and after the incubation.Patch clamp was used to measure the current of potential functional in mixed transfection cells. Results Compared with the WT group,A561V-mutation could cause trafficking deficient of hERG protein.The PM expression of hERG in mutant group was significantly reduced(P＜0.01).The expression of Rer1 in mutation and mixed transfection groups decreased significantly(P＜0.01).Knockdown of Rer1 promoted the forward transport of mature hERG.Besides,after incubation with Baf A1,the mature hERG protein in WT and mutant groups increased significantly(P＜0.05),while the immature hERG in the mixed transformation group was significantly increased(P＜0.05).Relative density of tail current was elevated following incubation with Baf A1 compared with control. Conclusions Rer1 is involved in the transport of hERG potassium channel and inhibits the forward transport of some abnormal hERG.Baf A1 significantly enhances the tail current density of mixed transfection cells.

Key words: chaperone, Rer1, hERG, LQTS