酵母Dop1及其同源蛋白DOPEY对细胞糖基化和囊泡运输影响的研究

蛋白质糖基化是一种保守的翻译后修饰,对多种细胞现象至关重要。在酵母或动物细胞高尔基体中的糖链处理由结构相似的糖基转移酶或糖苷酶催化。囊泡运输等多种因素会影响糖基转移酶在高尔基体中的稳态定位,进而影响糖基化。该研究探讨高尔基外周蛋白Dop1对细胞糖基化和囊泡运输的影响。共聚焦荧光显微镜活细胞成像显示,Dop1主要定位于晚期高尔基体。Dop1及其相互作用蛋白Neo1(P4 ATPase)均参与高尔基体后期的囊泡运输。此外,Dop1介导糖基转移酶Och1的逆向运输而影响糖基化。进一步,哺乳动物DOPEY1和DOPEY2是酵母Dop1的同源蛋白。DOPEY1或DOPEY2的缺失导致高尔基体结构的改变,轻微地影响细胞糖基化。综上,酵母Dop1和哺乳动物DOPEY都参与了细胞后期的蛋白质囊泡运输,并影响高尔基体形态或糖基化。

Study of Yeast Dop1 and Its Homologous DOPEY Proteins on Cellular Glycosylation and Vesicular Transport

Protein glycosylation is a conserved post-translational modification that is critical for various cellular phenomena.Structure similar glycosyltransferases or glycosidases cooperate to modify glycan structures in the Golgi of yeast or mammalian cells.The steady state localization of glycosyltransferases in the Golgi apparatus is influenced by vesicular transport and a variety of factors.This study explored the effect of Golgi peripheral protein Dop1 on cellular glycosylation.Live cell imaging by confocal fluorescence microscopy showed that Dop1 was predominantly localized to the late golgi apparatus.Both Dop1 and its interacting protein Neo1(P4-ATPase)were involved in vesicular trafficking at the late golgi apparatus.In addition,Dop1 mediated the retrograde transport of Och1 glycosyltransferase.Furthermore,deletion of the mammalian Dop1 homologs DOPEY proteins led to changes in the structure of the Golgi,which weakly affected the glycosylation.Our results indicated that both yeast Dop1 and mammalian DOPEYs were involved in protein transport at the late stage of vesicular trafficking pathway and affected Golgi morphology or glycosylation.