アブシシ酸受容体 PYR1は,アブシシ酸との複合体である
Julia Santiago1, Florine Dupeux, Adam Round
1Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, ES-46022 Valencia, Spain.
Nature
|November 10, 2009
まとめ
植物ホルモンアブシシ酸 (ABA) のシグナル伝達は,ストレスへの適応に不可欠です. 研究者らはABA受容体PYR1の結晶構造を決定し,ホルモン結合とシグナル伝達経路の調節に不可欠な形状の変化を明らかにした.
科学分野:
- 植物生物学 植物生物学
- 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
背景:
- アブシシ酸 (ABA) は,ストレス反応と発達を調節する重要な植物ホルモンです.
- 細胞内ABA受容体 (PYR/PYL/RCARファミリー) は,ABAシグナル伝達におけるネガティブレギュレータ (PP2Cs) を抑制する.
- ABA受容体の構造を理解することは,植物ストレス反応の研究に不可欠です.
研究 の 目的:
- ABA結合と受容体活性化の構造的基礎を解明する.
- ABA結合時にPYR1受容体の構成変化についての洞察を提供するため.
主な方法:
- X線結晶学を用いて,アラビドプシス・サリアナ PYR1.1.の構造を決定した.
- リガンド結合状態と無結合状態の両方のPYR1ジマー構造の分析.
主要な成果:
- アラビドプシス・サリアナ PYR1の結晶構造が決定され,二次元的な形を明らかにした.
- 1つのPYR1サブユニットはABAに結合し,もう1つは空であり,異なる構成状態を示した.
- リンガンド結合サブユニットはABA分子の上でループの閉塞を示し,空のサブユニットはコンフォーマーションの柔軟性を示すオープンチャネルを示した.
結論:
- 特定のループの適合の変化は,ABA-PYR1複合体の安定化に極めて重要です.
- ABA結合ポケットの構造的詳細は,新しい植物ストレス活性化分子の開発のための基礎を提供します.
関連する概念動画
Rab Proteins
4.0K
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...
4.0K
Allosteric Proteins-ATCase
4.8K
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
4.8K
Assembly of Signaling Complexes
4.7K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
4.7K
Cell Signaling in Plants
4.5K
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
4.5K
GPCR Desensitization
6.1K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
6.1K
IP3/DAG Signaling Pathway
12.5K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
12.5K


