Rab GDP解離阻害剤とプレニル化YPT1GTPアゼとの複合体の構造
Alexey Rak1, Olena Pylypenko, Thomas Durek
1Department of Physical Biochemistry, Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
まとめ
モノプレニレートされたYpt1:RabGDI複合体の構造を決定し,RabGDIがRabタンパク質によるヌクレオチド放出を阻害する方法を明らかにし,人間の精神的遅滞に関連した変異の洞察を提供しました.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- 細胞生物学 細胞生物学
背景:
- Rab/Ypt GTPasesは,真核細胞の膜交通の重要な調節体である.
- ラブ・グアナイン・ヌクレオチド分裂阻害剤 (RabGDI) は,ヌクレオチドの放出を阻害することによって,ラブ・GTPaseの機能を制御する.
研究 の 目的:
- モノプレニル化Ypt1:RabGDI複合体の構造を決定する.
- RabGDIがニュクレオチドの放出を阻害する分子メカニズムを解明する.
- RabGDIに関連するヒト疾患を理解するための構造的基礎を提供すること.
主な方法:
- 化学合成とタンパク質工学を用いて,Ypt1:RabGDI複合体を生成した.
- 複合体の構造を1.5アングストームの解像度で解明するために,X線結晶学を用いた.
主要な成果:
- この構造は,RabGDIがモノプレニル化Ypt1タンパク質に結合する方法を示しています.
- イソプレノイド結合は形状の変化を誘導し,RabGDIの領域IIに穴を開く.
- この構造的洞察は,Rabタンパク質による核酸放出をRabGDIが抑制することを説明する.
結論:
- 決定された構造は,RabGDIの抑制機能のための分子基盤を提供します.
- この発見は,人間の精神的遅滞に関連するRabGDI変異体についての洞察を提供します.
- この研究は,分子レベルでの膜交通規制の理解を前進させる.
関連する概念動画
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...
Large G-proteins, also known...
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...
Rab 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...
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...
Large G-proteins, also known...
Small GTPases - Ras and Rho
Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
Three regulatory proteins control their activity:
Activation and Inactivation of G Proteins
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...


