まとめ
エストロゲンホルモンの作用の標準モデルが挑戦されています. 占有されていないエストロゲン受容体は,完ぺきな細胞の細胞質ではなく,主に核に位置しています.
科学分野:
- エンドクリノロジー エンドクリノロジー
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
背景:
- 確立されたモデルは,エストロゲン受容体 (ERs) が細胞質に存在し,エストロゲンと結合すると核に転移すると仮定しています.
- このモデルは主に,同質化された細胞製剤を用いた研究に基づいており,人工物を導入することがあります.
- 新興の証拠は,未使用のERが核であり,細胞プラズマの局所化は抽出の人工物である可能性があることを示唆しています.
研究 の 目的:
- 無傷の細胞内の未占用エストロゲン受容体の細胞下局部化を調査する.
- ER分布に関するステロイドホルモンの作用の支配的なモデルに異議を唱える.
主な方法:
- GH3細胞 (ネズミの垂体腫瘍の起源) からサイトプラストとヌクレオプラストの分子を分離するために,サイトカラシンB誘発エヌクレアスを利用しました.
- これらの孤立した細胞分子の量化されたエストロゲン結合活性.
主要な成果:
- サイトプラストの分子は,最低限のエストロゲン結合活性を示した.
- 占拠されていないエストロゲン受容体のほとんどは,核分数 (核プラスト) と関連していることが判明しました.
結論:
- エストロゲンホルモンの作用の標準モデルでは,空いたERを細胞プラズマに置き換えるが,これは誤っている可能性が高い.
- 占有されていないエストロゲン受容体は,完ぺきなGH3細胞の核を主として占有しています.
関連する概念動画
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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 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...
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...
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...
Transducer Mechanism: Nuclear Receptors
Nuclear receptors, or NRs, are unique transcription factors that regulate gene transcription and affect the cellular pathways involved in reproduction, development, or metabolism. Their ability to be stimulated by small lipophilic ligands and control vital cellular processes makes them ideal drug targets. Nearly 10-15% of currently prescribed drugs target these receptors.
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:


