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Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
ゲトロトリメリックGタンパク質によるゴルギ構造の調節
C Jamora1, P A Takizawa, R F Zaarour
1Department of Biology, University of California San Diego, La Jolla 92093-0347, USA.
Cell
|December 11, 1997
まとめ
海洋スポンジの代謝産物であるイリマキノン (IQ) は,ARFとコアトーマーとは独立してゴルギの膀化を引き起こします. このプロセスは,自由ベタガマサブユニットがゴルギ・スタック・ベシキュレーションを誘発するヘトロトリメリックGタンパク質の活性化を含みます.
科学分野:
- 海洋自然産物とは
- 細胞生物学 細胞生物学
- 分子シグナル伝達です.
背景:
- 海洋スポンジの代謝産物であるイリマキノン (Ilimaquinone,IQ) は,ゴルギ・スタックの完全な膀化を誘発することが知られている.
- IQ媒介によるゴルギの水泡形成の正確なメカニズムと,既知の水泡形成経路との関連は不明である.
研究 の 目的:
- イリマキノン (IQ) 誘発のゴルギの水泡形成の背後にある分子機構を解明する.
- IQ媒介のゴルギ水泡形成には,ARFやコアトーマーなどのCOPI水泡形成経路の成分が必要かどうかを判断する.
主な方法:
- 浸透した細胞におけるIQ媒介のゴルギ胞体の再構成.
- 膀化プロセスにおけるARF,コアトーマー,ヘテロトリメリックGタンパク質の役割の調査.
- Gアルファ (s) -GDPとGアルファ (i3) -GDPの阻害効果とベタガマサブユニットの効果の評価.
主要な成果:
- IQ媒介のゴルギ水泡形成は,ARFとコアトーマーとは無関係に進行し,COPI水泡形成の重要な要因である.
- このプロセスは,G alpha(s) -GDPとG alpha(i3) -GDPによって阻害され,ヘトロトリメリックGタンパク質が関与することを示唆しています.
- IQなしでベタガマサブユニットを添加するだけで,ゴルギのスタックベシキュレーションを誘発するには十分です.
結論:
- IQ誘発のゴルギの膀化は,ヘトロトリメリックGタンパク質の活性化によって媒介されます.
- ゴルギの膀化を誘発する活性種は,活性化されたアルファサブユニットではなく,自由ベタガマサブユニットです.
関連する概念動画
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One of the first identified Golgi matrix proteins was GM130, a rod-like protein located in the cis-Golgi. Subsequently, many Golgi...
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GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
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Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...

