アラビドプシスのオクシントランスポーターPIN3の構造とメカニズム
Nannan Su1, Aiqin Zhu2, Xin Tao3
1Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Nature
|August 2, 2022
まとめ
研究者はオキシントランスポーターであるPIN3の構造を視覚化し,その基板と阻害物質との結合を明らかにした. これは植物ホルモンの輸送メカニズムに 洞察を与えます
科学分野:
- 植物生物学
- 分子生物学
- 構造生物学
背景:
- ピン型 (PIN) タンパク質は,植物の成長と発達を調節する重要なオキシントランスポーターです.
- アクシン輸送メカニズムの解読には 構造を理解することが重要です
研究 の 目的:
- アラビドプシス・タリアナPIN3の冷凍電子顕微鏡構造を決定する
- 基質 (インドル3酸) と阻害剤 (NPA) の認識のための構造的基礎を解明する.
- PIN媒介によるオキシン輸送に対するNPA抑制の分子機構を明らかにする.
主な方法:
- 高解像度構造を得るための冷凍電子顕微鏡 (冷凍EM).
- 構造と機能の分析
- コンピュータによる研究
主要な成果:
- PIN3のアポ状態,基板結合状態,および阻害剤結合状態の構造を決定した.
- PIN3は,二重化に関与する特定のトランスメブランヘリックスを持つホモジマーとして機能する.
- 各サブユニットのダイマー界面と内向きの形状で 細胞外の大穴を特定した.
- インドル3酸とNPAの結合部位と認識メカニズムを明らかにした.
- NPA抑制の分子メカニズムを明らかにした.
結論:
- PIN3の二重構造はオキシン輸送のためのプラットフォームを提供します.
- 構造はオキシンの"エレベーターのような"輸送モデルをサポートします.
- これらの発見は,PIN媒介によるオクシン輸送と抑制の詳細な分子理解を提供します.
さらに関連する動画
関連する概念動画
Protein Transport to the Inner Chloroplast Membrane
2.1K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
2.1K
Cell Signaling in Plants
5.7K
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...
5.7K
Protein Transport to the Thylakoids
2.3K
Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal...
2.3K
Protein Transport to the Outer Chloroplast Membrane
2.0K
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
2.0K
Short-distance Transport of Resources
16.3K
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
16.3K
ABC Transporters: Importer
2.8K
ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
2.8K


