関連する実験動画
Updated: May 12, 2026
10:18
Analysis of Protein Import into Chloroplasts Isolated from Stressed Plants
Published on: November 1, 2016
核タンパク質の輸入の最初のステップに不可欠なタンパク質の分離
D Görlich1, S Prehn, R A Laskey
1Wellcome/CRC Institute, Cambridge, England.
Cell
|December 2, 1994
まとめ
研究者らは,クセノプスの卵で核インポートに不可欠なタンパク質であるインポートンを精製した. このタンパク質は,信号に依存した核封筒結合を促進し,そのcDNAはクローンされ,発現され,酵母SRP1pとの類似性を明らかにしました.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- タンパク質の輸入
背景:
- 細胞の機能には,細胞核への選択的タンパク質輸送が不可欠である.
- 核の輸入を制御するメカニズムは複雑で,特定のタンパク質の相互作用を含む.
研究 の 目的:
- 選択的な核タンパク質の輸入に関与するタンパク質を特定し,特徴づけること.
- 核インポートを媒介する特定の細胞タンパク質の役割を明らかにする.
主な方法:
- クセノプス (Xenopus) の卵から細胞性タンパク質を精製する.
- クローニング,シーケンシング,および対応するcDNAの発現.
- 精製された成分を用いて,インビトロで核輸入の復元.
主要な成果:
- 選択的核インポートに不可欠なインポートというサイトゾール性タンパク質を精製した.
- インポルティンは,カリオフィルのタンパク質の核包膜への信号依存結合を媒介する.
- Importinは酵母SRP1pとの配列同一性を共有しており,機能が保存されていることを示唆しています.
- 信号に依存した核インポートは,浄化されたインポートとRan/TC4.で再構成できます.
結論:
- インプルトインは,選択的なタンパク質の核への輸入の重要な媒介である.
- この発見は,核輸送の分子機構の洞察を提供している.
- 進捗調査により,原子力輸入の規制に関与する追加の要因が明らかになる可能性があります.
関連する概念動画
01:45Overview of Protein Sorting and Transport
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Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
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01:34Nuclear Protein Sorting
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
01:46Nuclear Localization Signals and Import
Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...
01:42Nuclear Export
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
01:45Regulation of Nuclear Protein Sorting
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
01:39Mitochondrial Precursor Proteins
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial precursors...
Most of the mitochondrial precursors...