真空のCa2+活性化チャネルであるTPC1は発芽と口腔の動きを調節する
Edgar Peiter1, Frans J M Maathuis, Lewis N Mills
1Biology Department, Area 9, University of York, PO Box 373, York YO10 5YW, UK.
Nature
|March 18, 2005
まとめ
植物細胞は反応のためにカルシウムシグナル伝達を用いる. 研究者らは,TPC1遺伝子を重要なカルシウムチャネルとして特定し,植物成長と口腔機能に不可欠である.
科学分野:
- 植物分子生物学 植物分子生物学
- 細胞シグナリング
- イオンチャネル機能のイオンチャネル機能
背景:
- サイトソリックフリーカルシウム (Ca2+cyt) は,植物細胞における重要なシグナル伝達分子である.
- 刺激によって誘発されたCa2+がサイトゾールに流入すると,下流反応が活性化されます.
- これらのCa2+フロースを媒介する特定のイオンチャネルは,以前は知られていなかった.
研究 の 目的:
- 植物のカルシウム透過性イオンチャネルの分子同一性を特定する.
- 生理学的プロセスにおけるこれらのチャネルの役割を明らかにする.
主な方法:
- 植物イオンチャネルの電気生理学的特徴.
- アラビドプシス・タリアナを用いた遺伝子ノックアウト研究.
- アブシシ酸と細胞外カルシウムに対する植物反応の分析.
主要な成果:
- TPC1遺伝子は,Ca2+依存のCa2+放出チャネルをコードし,遅い真空チャネルとして知られています.
- TPC1を欠いたノックアウト変異体は,緩やかな真空管活性を示さなかった.
- ミュータントは,アブシシ酸による発芽抑制と,カルシウムに対する口腔反応の欠陥を示した.
結論:
- TPC1は,植物における重要なCa2+放出チャネルである遅い真空チャネルとして明確に識別されています.
- 細胞内Ca2+放出チャネルは,発芽と口腔の調節を含む植物生理学において基本的な役割を果たします.
関連する概念動画
01:27C4 Pathway and CAM
38.0K
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
C4 Pathway
The C4 pathway is used by plants such as...
38.0K
02:12Short-distance Transport of Resources
14.5K
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.
14.5K
02:04Regulation of Transpiration by Stomata
26.2K
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
26.2K
01:24Protein Transport to the Stroma
1.5K
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
1.5K
01:11Protein Transport to the Outer Chloroplast Membrane
1.6K
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.
1.6K
01:18Protein Transport to the Inner Chloroplast Membrane
1.7K
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...
1.7K