以拟南芥蛋白质作"种子"在蓖麻(Riciuns communis L.)的蛋白质数据库中搜索,结合关键字搜索方法,获得10个蓖麻油体固醇蛋白质,通过生物信息方法对这些蛋白质进行分析。结果表明,10个蓖麻油体固醇蛋白质外显子的数目和内含子...以拟南芥蛋白质作"种子"在蓖麻(Riciuns communis L.)的蛋白质数据库中搜索,结合关键字搜索方法,获得10个蓖麻油体固醇蛋白质,通过生物信息方法对这些蛋白质进行分析。结果表明,10个蓖麻油体固醇蛋白质外显子的数目和内含子的位点较保守;氨基酸残基数、分子量和等电点相差不大;疏水性/亲水性和跨膜结构分析表明,成员间在N-末端第25个氨基酸位点有一个跨膜结构;主要由α螺旋、β折叠和无规则卷曲组成;三维结构符合SDR超家族特点;NADPH结合区域、活性位点较保守,膜锚定区域和固醇结合区域差异较大。展开更多
Oleosin, caleosin and steroleosin are normally expressed in developing seed cells and are targeted to oil bodies. In the present work, the cDNA of each gene tagged with fluorescent proteins was transiently expressed i...Oleosin, caleosin and steroleosin are normally expressed in developing seed cells and are targeted to oil bodies. In the present work, the cDNA of each gene tagged with fluorescent proteins was transiently expressed into tobacco protoplasts and the fluorescent patterns observed by confocal laser scanning microscopy. Our results indicated clear differences in the endocellular localization of the three proteins. Oleosin and caleosin both share a common structure consisting of a central hydrophobic domain flanked by two hydrophilic domains and were correctly targeted to lipid droplets （LD）, whereas steroleosin, characterized by an N-terminal oil body anchoring domain, was mainly retained in the endoplasmic reticulum （ER）. Protoplast fractionation on sucrose gradients indicated that both oleosin and caleosin- green fluorescent protein （GFP） peaked at different fractions than where steroleosin-GFP or the ER marker binding immunoglobulin protein （BiP）, were recovered. Chemical analysis confirmed the presence of triacylglycerols in one of the fractions where oleosin-GFP was recovered. Finally, only oleosin- and caleosin-GFP were able to reconstitute artificial oil bodies in the presence of triacylglycerols and phospholipids. Taken together, our results pointed out for the first time that leaf LDs can be separated by the ER and both oleosin or caleosin are selectively targeted due to the existence of selective mechanisms controlling protein association with these organelles.展开更多
文摘以拟南芥蛋白质作"种子"在蓖麻(Riciuns communis L.)的蛋白质数据库中搜索,结合关键字搜索方法,获得10个蓖麻油体固醇蛋白质,通过生物信息方法对这些蛋白质进行分析。结果表明,10个蓖麻油体固醇蛋白质外显子的数目和内含子的位点较保守;氨基酸残基数、分子量和等电点相差不大;疏水性/亲水性和跨膜结构分析表明,成员间在N-末端第25个氨基酸位点有一个跨膜结构;主要由α螺旋、β折叠和无规则卷曲组成;三维结构符合SDR超家族特点;NADPH结合区域、活性位点较保守,膜锚定区域和固醇结合区域差异较大。
文摘Oleosin, caleosin and steroleosin are normally expressed in developing seed cells and are targeted to oil bodies. In the present work, the cDNA of each gene tagged with fluorescent proteins was transiently expressed into tobacco protoplasts and the fluorescent patterns observed by confocal laser scanning microscopy. Our results indicated clear differences in the endocellular localization of the three proteins. Oleosin and caleosin both share a common structure consisting of a central hydrophobic domain flanked by two hydrophilic domains and were correctly targeted to lipid droplets （LD）, whereas steroleosin, characterized by an N-terminal oil body anchoring domain, was mainly retained in the endoplasmic reticulum （ER）. Protoplast fractionation on sucrose gradients indicated that both oleosin and caleosin- green fluorescent protein （GFP） peaked at different fractions than where steroleosin-GFP or the ER marker binding immunoglobulin protein （BiP）, were recovered. Chemical analysis confirmed the presence of triacylglycerols in one of the fractions where oleosin-GFP was recovered. Finally, only oleosin- and caleosin-GFP were able to reconstitute artificial oil bodies in the presence of triacylglycerols and phospholipids. Taken together, our results pointed out for the first time that leaf LDs can be separated by the ER and both oleosin or caleosin are selectively targeted due to the existence of selective mechanisms controlling protein association with these organelles.
