在分泌途径中,需要循环林同源ninaA
N J Colley1, E K Baker, M A Stamnes
1Howard Hughes Medical Institute University of California, San Diego, La Jolla 92093.
Cell
|October 18, 1991
概括
尼纳A基因的突变破坏了Drosophila光受体细胞内内质网膜中的罗多素1 (Rh1) 的运输. 这突出了ninaAA的重点.
科学领域:
- 分子和细胞生物学分子和细胞生物学
- 神经科学是一个神经科学.
- 遗传学 是一个遗传学.
背景情况:
- Rhodopsin 1 (Rh1) 对于Drosophila R1-R6光受体细胞中的光传导是必不可少的.
- 环素,像ninaA一样,是已知参与蛋白质折叠的基基-基 cis-trans 异构酶.
- 之前的研究表明,ninaA突变导致Rh1素水平显著降低.
研究的目的:
- 为了研究 ninaA 基因在内质网膜 (ER) 中的功能及其在 Rh1 opsin 传输中的作用.
- 阐明 ninaA 影响 Rh1 opsin 处理和贩运的机制.
主要方法:
- 对具有 ninaA 基因突变的 Drosophila 光受体细胞的分析.
- 显微镜检查以观察ER形态和opsin定位.
- 在分泌囊泡中追踪ninaA和Rh1的局部化研究.
主要成果:
- ninaA突变严重抑制了来自ER的Rh1素运输.
- 光受体细胞在ninaA突变体中显示出ER水箱的剧烈积累.
- ninaA和Rh1在分泌囊泡中同位,这表明ninaA在分泌途径的后期阶段的作用.
结论:
- ninaA在ER中起作用,以促进适当的Rh1选择折叠和/或运输.
- ninaA对于Rh1通过分泌途径的细胞内蛋白贩运至关重要.
- 这些发现表明环素在蛋白质折叠和贩运中起着更广泛的作用.
相关概念视频
01:33Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
01:32Pinching-off of Coated Vesicles
Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...
01:33Coat Assembly and GTPases
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
01:45ER 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...
00:50Anaphase Promoting Complex
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
01:28Protein Translocation Machinery on the ER Membrane
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 translocon complex.
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 translocon complex.