SEC13/31 COPIIコートケージの構造について
Scott M Stagg1, Cemal Gürkan, Douglas M Fowler
1National Resource for Automated Molecular Microscopy, Departments of Cell, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Nature
|January 13, 2006
まとめ
コートタンパク質複合体II (COPII) Sec13/31 コンポーネントは,最小限のケージに自己組み立てられ,新しい立方体構造を明らかにします. この発見は,エンドプラズマ網膜の貨物輸出におけるCOPIIタンパク質の役割を再定義する.
科学分野:
- 細胞生物学 細胞生物学
- 構造生物学 構造生物学とは
- バイオケミストリー バイオケミストリー
背景:
- ユカリオット細胞内膜はダイナミックで,特殊な機械を介して通信します.
- コートタンパク質複合体II (COPII) は,エンドプラズマ網膜 (ER) から貨物の輸出を媒介する.
- COPIIは,Sar1 GTPase,Sec23/24 (貨物選択),Sec13/31 (構造的役割) を含む.
研究 の 目的:
- COPIIコンポーネントの自己組み立てを調査する.
- Sec13/31.1.によって形成された最小のケージの構造を決定する.
- COPIIコート組立におけるSec23/24の役割を明らかにする.
主な方法:
- クリオ電子顕微鏡 (cryo-EM) と単粒子の分析.
- Sec13/31のケージの3次元再構築.
- COPIIコンポーネントの相互作用の生化学分析.
主要な成果:
- Sec13/31は,Sec23/24とは独立して,最小限のケージに自己組み立てられます.
- Sec13/31のケージのための新しい立方体幾何学が30 Åの解像度で決定されました.
- これらのケージは,柔軟な格子形成と多様な容器生成の可能性を示しています.
結論:
- Sec13/31 自己組み立ては,COPII.の主要なケージ構造を形成する.
- Sec23/24は,Sec13/31アセンブリを局所化し,多価リガンドとして作用する可能性があります.
- このモデルは,COPIIコート組立とER貨物輸出の理解を洗練します.
関連する概念動画
01:19Septins
Septins are protein filaments forming the cytoskeleton along with the microtubules, microfilaments, intermediate filaments, and other accessory proteins. In 1971 while studying the cell division cycle in mutant Saccharomyces cerevisiae Harwell et al. first identified the septin-related genes playing a crucial role in yeast cytokinesis. Fluorescence microscopy revealed that these proteins localize at the budding neck as rings. These ring-like proteins were then named Septins by John Pringle, and...
00:59COP 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...
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...
01:12Clathrin 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...
01:25Structure of Cadherins
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This diversity of cadherins...
01:23Catenins
Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...