Sec23との連続的な相互作用は,膀の流れの方向を制御する
Christopher Lord1, Deepali Bhandari, Shekar Menon
1Department of Cellular and Molecular Medicine, Howard Hughes Medical Institute, University of California at San Diego, La Jolla, California 92093-0668, USA.
Nature
|May 3, 2011
まとめ
膀輸送の方向性は,Sec23p/Sec24pコート複合体に依存しています. Golgiに関連したHrr25pキナーゼはコートをリン酸化し,膀融合を可能にし,一方的なER-Golgiトラフィックを確保します.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- メンブラン取引 メンブラン取引
背景:
- 膀の移動の方向性は,細胞の機能にとって極めて重要です.
- Sec23p/Sec24pコート複合体は,エンドプラズマ網膜 (ER) から水泡の芽生えを媒介する.
- コート放出の正確なメカニズムとその膜融合との関係は不明である.
研究 の 目的:
- ER-Golgiベシクル交通方向性におけるSec23p/Sec24pコート複合体の役割を調査する.
- コート放出と膀融合を調節する要因とメカニズムを特定する.
- 片方向輸送が維持され,逆融合が防止される方法を理解する.
主な方法:
- イーストトランスポートアッセイを用いて,ER-derived vesiclesを追跡した.
- コート成分と他の要因の間のタンパク質-タンパク質の相互作用を調査した.
- コート改変におけるゴルギ関連キナーゼ Hrr25p の役割を分析した.
主要な成果:
- ER-derived vesiclesは,Golgiに到達するまでコートを保持する.
- ゴルジ関連Hrrr25pはSec23p/Sec24pコート複合体をリン酸化する.
- コート・フォスフォリレーションは膀融合に不可欠であり,デフォスフォリレーションは芽生えに必要である.
- Sec23pは,TRAPPIとHrr25pと交互に作用し,方向的なトラフィックを確保します.
結論:
- ゴルギのHrr25pによるコートリン酸化は,ER-ゴルギ水泡融合の重要なステップです.
- Sec23pの配列相互作用は,膀輸送の方向性を調節する.
- これらのメカニズムは哺乳類の細胞に保存されており,その根本的な重要性を強調しています.
関連する概念動画
Overview 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...
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...
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...
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...
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...
Fusion of Secretory Vesicles with the Plasma Membrane
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...


