低分子量GTP结合蛋白的定位到外细胞和内细胞区
P Chavrier1, R G Parton, H P Hauri
1European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Cell
|July 27, 1990
概括
研究人员在哺乳动物细胞中发现了11种GTP结合蛋白. 三种蛋白质,Rab2,Rab5和Rab7,被局部化到特定的细胞区,参与蛋白质运输和内细胞分裂.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 贩卖蛋白质 贩卖蛋白质 是一个问题.
背景情况:
- YPT1/SEC4基因家族编码GTP结合蛋白,对于酵母体中的囊泡运输至关重要.
- 了解这些蛋白质的哺乳动物同类对于阐明细胞内贩运途径至关重要.
研究的目的:
- 为了分离和表征哺乳动物同类酵母YPT1/SEC4.4的GTP结合蛋白.
- 确定这些哺乳动物蛋白质在外细胞和内细胞通路内的亚细胞局部.
主要方法:
- 从MDCK细胞库中分离了11个编码假定GTP结合蛋白的cDNA克隆.
- 免疫光和免疫电子显微镜使用亲和性纯化抗体定位蛋白质.
- 与已识别的蛋白质相关的细胞结构的表征.
主要成果:
- 成功分离出11个同源克隆,包括哺乳动物的rab2,rab5和rab7.
- rab2定位在ER和Golgi之间的中间区间.
- rab5局部存在于血和早期内基因组中.
- rab7局部存在于晚期内分泌体.
结论:
- GTP结合蛋白的YPT1/SEC4亚家族的成员在哺乳动物细胞中特别局部化到不同的外细胞和内细胞亚区.
- 这些发现凸显了这些蛋白质在物种间细胞内贩运中的保留作用.
相关概念视频
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GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
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Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.


