酵母Sec蛋白与穿越内分泌网膜膜的多相互作用
A Müsch1, M Wiedmann, T A Rapoport
1Max-Delbrück-Center for Molecular Medicine, Berlin Buch, Germany.
Cell
|April 17, 1992
概括
新生分泌蛋白在酵母体内细胞内网膜转位过程中与Sec61p和Sec62p相互作用. 这些必不可少的蛋白质在蛋白质通过膜的过程中发挥着直接作用.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 蛋白质在内细胞网膜 (ER) 上的转移对于分泌通路的功能至关重要.
- 已知Sec61p和Sec62p是Saccharomyces cerevisiae中涉及蛋白质运输的重要基因.
- 这些蛋白质在转位过程中的精确机制和直接参与尚未完全阐明.
研究的目的:
- 研究在转位过程中新生分泌蛋白和ER膜蛋白之间的物理相互作用.
- 确定Sec61p和Sec62p在蛋白质转位过程中的作用.
- 阐明转位过程中Sec蛋白与蛋白相互作用的动态.
主要方法:
- 用光交叉链接实验来检测蛋白质之间的物理接触.
- 在酵母菌Saccharomyces cerevisiae模型系统中进行了研究.
- 在转位的ATP依赖和ATP独立阶段对蛋白质相互作用的分析.
主要成果:
- 新生分泌蛋白被证明在ER膜通道期间与Sec61p和Sec62p发生物理接触.
- Sec61p显示连续接触,而Sec62p显示暂时参与.
- 蛋白质转位涉及与Sec蛋白质的不同ATP依赖和独立的相互作用.
结论:
- Sec61p和Sec62p直接参与通过ER膜的分泌蛋白的转移.
- 这些发现提供了对这些基本转移因素的作用的机制性见解.
- 这项研究支持Sec蛋白质作为蛋白质运输的直接导体的模型.
相关概念视频
Yeast Signaling
15.7K
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
15.7K
Directing Proteins to the Rough Endoplasmic Reticulum
12.1K
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
12.1K
Cotranslational Protein Translocation
8.4K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
8.4K
Tail-anchoring of Proteins in the ER Membrane
2.8K
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
2.8K
Post-translational Translocation of Proteins to the RER
5.7K
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
5.7K
Protein Translocation Machinery on the ER Membrane
5.6K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
5.6K


