一个SNARE-适配器交互是一种新模式的货物识别在克拉特林涂层囊泡
Sharon E Miller1, Brett M Collins, Airlie J McCoy
1University of Cambridge, CIMR, Wellcome Trust/MRC Building, Hills Road, Cambridge, CB2 0XY, UK.
Nature
|November 23, 2007
概括
可溶性NSF附着蛋白受体 (SNAREs) 通过与克拉特林外层组件的直接相互作用将其分类为囊泡. 这项研究揭示了Vti1b SNARE和epsinR之间的新型表面相互作用,这对于适当的蛋白质贩运至关重要.
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:
- 可溶性NSF附着蛋白受体 (SNAREs) 介导囊泡融合特异性.
- 必须正确地将SNARE分类为输送囊泡.
- 克拉特林覆盖的囊泡是细胞内贩运的关键.
研究的目的:
- 描述SNARE将分类成氨酸涂层囊泡的分子基础.
- 为了阐明SNARE Vti1b和克拉特林适配器epsinR (EPNR) 之间的相互作用.
主要方法:
- 对Vti1b H(abc) 域和epsinR.R.的结构分析
- 同复杂的结构确定.
- 在体外相互作用测定和点突变发生.
主要成果:
- 在Vti1b和epsinR之间进行了特定的表面相互作用 (Kd 22 μM).
- 相互作用涉及大约15个残留物的互补表面贴片.
- 这种接口的破坏导致Vti1b错位到晚期内分泌体/溶解体.
结论:
- 这种交互代表了通过克拉特林层识别货物的新类别,与AP和GGA适配器结合不同.
- 这种机制提供了特异性,并避免了线性图案的竞争.
- 类似的新型相互作用可能会调节其他SNARE的戈尔吉后贩运.
相关概念视频
Pinching-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...
Coat 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...
SNAREs and Membrane Fusion
Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion.
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
Vesicular Tubular Clusters
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
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.


