酿酒酵母的TORC1(target of rapamycin complex 1)复合体是由Kog1、Lst8、Tco89以及Tor1或者Tor2组成,其中,Tor1和Tor2最初是作为雷帕霉素作用靶点而在1991年被发现的。近年来的一些研究表明,TORC1以及另一个相似的复合体TORC2参与营养...酿酒酵母的TORC1(target of rapamycin complex 1)复合体是由Kog1、Lst8、Tco89以及Tor1或者Tor2组成,其中,Tor1和Tor2最初是作为雷帕霉素作用靶点而在1991年被发现的。近年来的一些研究表明,TORC1以及另一个相似的复合体TORC2参与营养代谢、核糖体合成、细胞周期、自噬衰老等细胞进程。近几年来对TORC1上游调控元件EGO(escape from rapamycin-induced growth arrest)复合体的深入研究,很大程度上解释了TORC1对氨基酸的感知途径。核糖体的生物合成是高度耗能的过程,而TORC1在r RNA转录及核糖体蛋白合成的过程中起到重要的控制作用。该文以酿酒酵母TORC1为例,回顾它的发现过程,并综述近几年在TORC1上游调控元件以及核糖体合成中作用的研究进展。展开更多
Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, p...Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, particularly in rice, remain largely unknown. Here we describe the characterization of wspl, a rice mutant with white-stripe leaves and panicles. Notably, wspl exhibited nearly white immature panicles at the heading stage. Transmission electron microscopy analysis and chlorophyll content measurement re- veale i a chloroplast developmental defect and reduced chlorophyll accumulation in wspl. Positional cloning of WSP1 found a point mutation in OsO4g51280, whose putative product shares high sequence similarity with MORF proteins. Complementation experiments demonstrated that WSP1 was responsible for the variegated phenotypes of wspl. WSP1 is localized to chloroplasts and the point mutation in wspl affected the editing of multiple organellar RNA sites. Owing to the defect in plastid RNA editing, chloroplast ribosome biogenesis and ndhA splicing were also impaired in wspl, which may affect normal chloroplast development in the leaves and panicles at the heading stage. Together, our results demonstrate the importance of rice WSP1 protein in chloroplast development and broaden our knowledge about MORF family members in rice.展开更多
文摘酿酒酵母的TORC1(target of rapamycin complex 1)复合体是由Kog1、Lst8、Tco89以及Tor1或者Tor2组成,其中,Tor1和Tor2最初是作为雷帕霉素作用靶点而在1991年被发现的。近年来的一些研究表明,TORC1以及另一个相似的复合体TORC2参与营养代谢、核糖体合成、细胞周期、自噬衰老等细胞进程。近几年来对TORC1上游调控元件EGO(escape from rapamycin-induced growth arrest)复合体的深入研究,很大程度上解释了TORC1对氨基酸的感知途径。核糖体的生物合成是高度耗能的过程,而TORC1在r RNA转录及核糖体蛋白合成的过程中起到重要的控制作用。该文以酿酒酵母TORC1为例,回顾它的发现过程,并综述近几年在TORC1上游调控元件以及核糖体合成中作用的研究进展。
文摘Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, particularly in rice, remain largely unknown. Here we describe the characterization of wspl, a rice mutant with white-stripe leaves and panicles. Notably, wspl exhibited nearly white immature panicles at the heading stage. Transmission electron microscopy analysis and chlorophyll content measurement re- veale i a chloroplast developmental defect and reduced chlorophyll accumulation in wspl. Positional cloning of WSP1 found a point mutation in OsO4g51280, whose putative product shares high sequence similarity with MORF proteins. Complementation experiments demonstrated that WSP1 was responsible for the variegated phenotypes of wspl. WSP1 is localized to chloroplasts and the point mutation in wspl affected the editing of multiple organellar RNA sites. Owing to the defect in plastid RNA editing, chloroplast ribosome biogenesis and ndhA splicing were also impaired in wspl, which may affect normal chloroplast development in the leaves and panicles at the heading stage. Together, our results demonstrate the importance of rice WSP1 protein in chloroplast development and broaden our knowledge about MORF family members in rice.
