核のCa2+貯蔵庫の枯渇によって抑制された核封筒の間の拡散
L Stehno-Bittel1, C Perez-Terzic, D E Clapham
1Department of Pharmacology, Mayo Foundation, Rochester, MN 55905, USA.
まとめ
核カルシウム貯蔵庫は,Xenopus laevisの卵細胞核膜を通過する中間の大きさの分子の通過を調節する. これらのカルシウム貯蔵庫を枯渇させると,10キロダルトンのデクストラン分子の核への侵入を阻害する.
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.
- Xenopus laevis オオサイト 核膜の研究
背景:
- 核毛孔複合体のモデルは,伝統的に70キロダルトン以下の分子に対して被動的拡散を想定しています.
- 分子輸送を調節する核包膜カルシウム貯蔵の役割は,完全に理解されていません.
研究 の 目的:
- 小分子運動がXenopus laevisの卵細胞核膜を横断する仕組みを研究する.
- 核エンベロープのカルシウム貯蔵が核輸入に与える影響を決定する.
主な方法:
- 完ぺきで,孤立したXenopus laevis卵細胞核と核膜 (ゴースト) 製剤を使用しました.
- イノシトール1,4,5-トリスフォスファートとカルシウムケレーターを使用して,操作された核貯蔵カルシウムレベル.
- 顕微鏡を用いて,光で標識されたデクストラン分子 (10キロダルトン) とより小さな分子 (ルシファー黄色,マンガン) の侵入を評価した.
主要な成果:
- 中間の大きさの分子 (10キロダルトンデクストラン) の拡散は,核カルシウム貯蔵庫の枯渇時にブロックされました.
- このカルシウムに依存する拡散の調節は,核の幽霊で観察されたように,核マトリックスとは独立して発生しました.
- より小さな分子 (500ダルトンルシファー黄色) とイオン (マンガネス) は,カルシウム枯渇後でも,自由に核と核幽霊に拡散します.
結論:
- 核包膜のカルシウム貯蔵は,核膜を横断する中間の大きさの分子の輸送を調節する上で重要な役割を果たします.
- 核カルシウム貯蔵庫の枯渇は,特に10キロダルトン程度の分子の核輸入を阻害する.
- 発見は,70キロダルトン未満の分子に対する被動的拡散モデルに挑戦し,カルシウムシグナル伝達を含む新しい規制機構を強調しています.
さらに関連する動画
10:03Isolation of CA1 Nuclear Enriched Fractions from Hippocampal Slices to Study Activity-dependent Nuclear Import of Synapto-nuclear Messenger Proteins
Published on: August 10, 2014
08:53Assay to Measure Nucleocytoplasmic Transport in Real Time within Motor Neuron-like NSC-34 Cells
Published on: May 16, 2017
関連する概念動画
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
Nuclear 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...
Nuclear 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...
Directionality of Nuclear Transport
Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This...
Regulation 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...
