【摘要】 目的探讨人自噬基因ATG12(hATG12)在酵母自噬过程中的作用。方法转化重组质粒pESC-URA-EGFP-hATG12(实验组)或pESC-URA-EGFP(对照组)的酵母用不同方法诱导自噬后,以荧光显微镜观察绿色荧光蛋白(EGFP)和含hAtg12的融合蛋白(EGFP-hATG12)在酵母中的表达与定位;以透射电镜观察前自噬体结构、自噬体和自噬小体的分布及结构特点。结果2组酵母细胞质内均见荧光,液泡内未见荧光,实验组荧光呈小点状分布;电镜下见自噬体由双层膜囊结构延伸而来,该双层膜囊结构靠近细胞膜。液泡内自噬小体由单层膜包裹。结论hATG12参与酵母自噬体最初的形成过程,定位于自噬体外膜上,在自噬体形成后脱离自噬体。自噬体膜最初可能来源于细胞膜。更多还原

【Abstract】 Objective To investigate the role of human autophagic gene ATG12(hATG12) in the process of autophagy in Saccharomyces.Methods The YPH500 strains carrying either the plasmid pESC-URA-EGFP-hATG12,or a control vector pESC-URA-EGFP was examined for autophagy.Enhanced green fluorescent protein(EGFP) signals were visualized with fluorescent microscope;and the formation of autophagosomes were examined by electron microscopy.Results EGFP and EGFP-hATG12 fusion protein was observed in cytosolic of yeast,and there was no fluorescence in the vacuole. Punctuate structures proximal to the vacuole were found in the YPH500 strain carrying the plasmid pESC-URA-EGFP-hATG12,electron microscopic examination showed,a few spherical bodies appeared in the vacuoles.The double-membrane of autophagosome was located near cell membrane and not from any other membrane structure.Conclusion hATG12 is related to the formation of autophagosome in the process of autophagy.Finally,hATG12 dissociated from the membrane upon completion of autophagosome formation.The double-membrane of autophagosome is probably drived from cell membrane.更多还原