NSF,SNAP,Rabタンパク質に対する異なる要求事項は,MDCK細胞の頂上および底側輸送におけるMDCKタンパク質に対する異なる要求事項です
E Ikonen1, M Tagaya, O Ullrich
1Cell Biology Programme, European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Cell
|May 19, 1995
まとめ
この研究は,上皮細胞の輸送経路のための明確な分子機構を明らかにしています. バソラテラル輸送はRab-NSF-SNAP-SNAREメカニズムを使用し,アピカル輸送は異なるコンポーネントを使用しています.
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:
- 偏極化された上皮細胞は,独特の頂上および底側膜領域を示します.
- 偏振膜輸送を制御する分子メカニズムを理解することは,細胞機能にとって極めて重要です.
研究 の 目的:
- NSF,SNAP,SNAREs,Rabタンパク質が,上皮細胞における偏光膜輸送における役割を調査する.
- 頂上対底横の輸送経路に関与する分子機構を区別するために.
主な方法:
- ストレプトリシンO浸透したマディン・ダービー犬腎臓 (MDCK) 細胞をインビトロシステムで利用しました.
- NSF,α-SNAP,Rab-GDIに対する抗体と神経毒素がTGNから血膜への輸送に与える影響を評価した.
主要な成果:
- トランス・ゴルギ・ネットワーク (TGN) からの基礎側輸送は,抗-NSF抗体によって抑制され,アルファ-SNAPによって刺激されました.
- TGNからのアピカル輸送は,抗NSF抗体やアルファ-SNAPの影響を受けませんでした.
- アピカル輸送は,Rab-GDIとテタヌス/ボツリヌス神経毒素に対して無感であり,それらはベースラテラル輸送を阻害した.
結論:
- Rab-NSF-SNAP-SNAREメカニズムは,特に基礎側膜輸送に関与しています.
- 明確な分子機構が,細胞の頂点表面への膀の配送を媒介する.
- この研究は,極化膜の密輸のための経路特異的な分子要件を明らかにします.
関連する概念動画
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...
01:45Overview of Protein Sorting and Transport
Eukaryotic cells have different membrane-bound organelles with distinct protein requirements. The process by which proteins are targeted to a specific organelle is called protein sorting.
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
01:14Rab Proteins
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
01:43SNAREs 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...
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.
01:25Rab 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.