概括
具有糖化位点的短从细胞中迅速分泌出来,比已知的蛋白质更快. 这表明快速的ER-Golgi传输不需要信号,但保留是需要的.
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:
- Asn-链接的糖化是发生在内质网膜 (ER) 中的一个关键的翻译后修饰.
- 该ER-戈尔吉通路对于蛋白质的加工,修饰和运输到各种细胞目的地至关重要.
- 了解蛋白质运输信号是解读细胞分泌机制的关键.
研究的目的:
- 通过ER-Golgi通路研究小的,糖化的运输动力学.
- 为了确定糖化本身是否作为快速蛋白质分泌的信号.
- 探索ER-Golgi通路内蛋白质保留的要求.
主要方法:
- 添加具有Asn-链接的糖化受体序列 (Asn-X-Ser/Thr) 的合成三酸,用于培养的中国仓鼠卵巢 (CHO) 和 HepG2 细胞.
- 在ER中监测三的糖化.
- 通过Golgi复杂处理,通过Golgi复杂处理追踪糖基化三的分泌到细胞介质中.
- 测量三分泌的半衰期.
主要成果:
- 在ER中成功地进行了三糖化,并在戈尔吉综合体中进行了加工.
- 分泌的三呈现出快速分泌的半衰期,大约为10分钟.
- 这种分泌速率明显快于使用相同途径观察到的已知蛋白质的分泌速率.
- 这些发现表明,寡糖链不是快速运输的主要信号.
结论:
- 从ER到Golgi,然后到细胞表面的快速有效的传输可能不需要特定的传输信号.
- 在ER-Golgi通路内保留为永久居民的蛋白质可能具有特定的保留信号.
- 这项研究强调了信号独立的快速蛋白质传输的潜力,以及局部化保留信号的必要性.
相关概念视频
Endoplasmic Reticulum
Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer membrane of the nucleus. This structural continuity integrates nuclear and cytoplasmic processes and facilitates efficient intracellular transport. This allows mRNA to move directly from the nucleus to ribosomes for efficient protein synthesis. As a result, the ER serves as a central site for the synthesis, processing, and distribution of...
Introduction to Membrane Traffic
The ER, Golgi apparatus, endosomes, and lysosomes work in tandem to modify, sort, and package proteins and lipids. An integrated membrane trafficking network facilitates the back and forth shuttling of molecules within different organelles in the same cell or across the cell membrane.
The transport of soluble and membrane proteins is mediated by transport vesicles that collect cargo from one cellular compartment and deliver it to another by fusing with the target organelle membrane. The Rab...
The transport of soluble and membrane proteins is mediated by transport vesicles that collect cargo from one cellular compartment and deliver it to another by fusing with the target organelle membrane. The Rab...
ER Retrieval Pathway
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The Endoplasmic Reticulum
The endoplasmic reticulum or ER makes up for more than half of the membranes in a cell and accounts for 10% of total cell volume. It is also the primary protein and lipid synthesis factory for most cell organelles, such as the Golgi apparatus, lysosomes, secretory vesicles, and the plasma membrane. Despite being the most extensive and functionally complex subcellular organelle, ER was the last to be discovered. After years of deliberation, Keith Porter and George Palade in the year 1954,...
Directing Proteins to the Rough Endoplasmic Reticulum
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...
Post-translational Translocation of Proteins to the RER
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...


