Abstract: Objective To explore the effects of alcoholic extracts of traditional Chinese medicines on the post-translational processing and trafficking of tyrosinase.Methods Human YUGEN8 amelanotic melanoma cells were grown in vitro;the cells were incubated with one of the seven traditional Chinese medicines,including Rhizoma Chuanxiong and psoralen.Protein analysis with Western blot,enzymolysis with endoglycosidase H (Endo H),and subcellular localization with laser confocal microscopy were performed.The expression,maturity and export from endoplasmic reticulum (ER) of tyrosinase in the treated cells were compared with those in the untreated controls.Results Compared with controls,an approximately 80-kDa,Endo H-resistant tyrosinase doublet,which represented mature glycoform of tyrosinase,was increased in melanocytes treated with Semen Cuscutae,and in those treated with Semen Persicae.Within those cells,tyrosinase was distributed outside ER resident protein calnexin.Conclusion Both Semen Cuscutae and Semen Persicae could induce tyrosinase maturation,stability and export from ER to distal site.

Key words: Monophenol monooxygenase, Cuscuta chinensis, Semen Persicae, Protein processing,post-translational, Protein transport