通过COPI层复合体中的GTPase开关通过coatomer对分类信号的解码
1Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA. jonathan@ximpact4.ski.mskcc.org
Cell
|April 13, 2000
概括
协同分子蛋白质复合体对货物分类信号识别到ARF1 GTP水解. 不同的信号调节这个过程,通过动力控制影响囊泡芽和货物分离.
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:
- 协同体介导选择性货物分类到COPI涂层囊泡中.
- ARF1 GTPase活性对于囊泡形成至关重要.
- 货物蛋白利用分类信号进行识别.
研究的目的:
- 为了研究由coatomer介导的分类信号识别和ARF1 GTP水解之间的合机制.
- 为了确定不同的排序信号如何影响由coatomer-dependent GTPase活动.
- 阐明动力控制在囊泡芽过程中的货物选择中的作用.
主要方法:
- 测量GTP水解速率的生物化学测定.
- 对不同分类信号的coatomer结合的分析.
- 在体外复制囊泡芽组件.
主要成果:
- 协同分子对货物识别到ARF1 GTP水解.
- hp24a的细胞质信号抑制了依赖于coatomer的GTP水解.
- 迪利辛检索信号不会影响共聚体GTPase的活性,尽管它们在结合方面竞争.
- 排序信号的选择在动力控制下,由coatomer控制.
结论:
- 协同体作为GTPase开关,控制货物选择.
- 由coatomer介导的GTPase丢弃途径排除了特定的载荷,比如dilysine标记的蛋白质.
- 这种机制在COPI囊泡形成过程中为货物分离提供了特异性.
相关概念视频
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
COP Coated Vesicles
Membrane-enclosed structures called vesicles transport proteins and lipids across the cell. The vesicles derive their cargo from the plasma membrane, Golgi, ER, or endosome. Coated vesicles are spherical, protein-coated carriers with a 50–100 nm diameter that mediate bidirectional transport between the ER and the Golgi. The distribution of proteins between the ER and Golgi complex is dynamic and is maintained by different coated vesicles. Their formation is driven by the assembly of different...
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...
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...


