通过大肠杆菌核蛋白复合体的信号序列识别
Nature
|October 22, 1992
概括
细菌P48/4.5SRNA复合体与新生蛋白质上的信号序列结合,其功能与蛋白质出口中的真核生物信号识别粒子 (SRPs) 相似.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 贩卖蛋白质 贩卖蛋白质 是一个问题.
背景情况:
- 疏水信号序列引导分泌蛋白穿过 prokaryotes 和eukaryotes 中的膜.
- 细胞信号识别粒子 (SRPs) 使用54K蛋白质来结合信号序列并保持蛋白质构成.
- 细菌的4.5SRNA和P48蛋白与哺乳动物的SRP成分有相似之处,但它们在蛋白质出口中的功能仍在争论中.
研究的目的:
- 研究细菌P48/4.5SRNA核糖核蛋白复合体在蛋白质出口中的作用.
- 为了确定细菌复合体是否作为信号识别粒子起作用.
主要方法:
- 哺乳动物和细菌SRP组件的比较序列分析.
- 研究4.5SRNA枯竭和P48过度生产对蛋白质前体积累的影响.
- 测试P48/4.5SRNA复合体与新生分泌蛋白信号序列的直接相互作用.
主要成果:
- 大肠杆菌中的P48蛋白和4.5SRNA与哺乳动物SRP54和7SRNA的序列相似性.
- 削减4.5SRNA或过度生产P48导致β-乳糖酶前体的积累.
- 证明P48/4.5SRNA复合体能够特异地与新生分泌蛋白的信号序列结合.
结论:
- 细菌中的P48/4.5SRNA核糖核蛋白复合体作为信号识别粒子起作用.
- 这种复合体在准分泌蛋白以通过内膜输出中起着至关重要的作用.
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