まとめ
コンカナヴァリンA (Con A) は,膜集積ではなく,ピノサイトーシス経由で,CHO細胞によって直接エンドサイト化されます. サイトカラーシンBは吸収を阻害するが,ConAの表面集積を促進し,エンドサイトーシスとキャピングの間の競争を示唆する.
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.
背景:
- 細胞表面に結合するコンカナヴァリンA (Con A) は,内分細胞を研究するためのモデルです.
- 直接的エンドサイトーシスとプラズマ膜結合 (キャピング) を含むCon A内化メカニズムは,完全に理解されていません.
研究 の 目的:
- 中国ハムスター卵巣 (CHO) 細胞におけるコンカナヴァリンA (Con A) 内化メカニズムを調査する.
- 直接的エンドサイトーシスと,Con A.のプラズマ膜結合 (キャッピング) を区別する.
主な方法:
- 無傷のCHO細胞とアセトンで抽出したCHO細胞の間接的免疫光.
- Con Aの局所化と細胞構造の観察.
主要な成果:
- Con Aは主に直接のピノサイトーシスによって内化され,シトプラズマのピノソームを形成する.
- 真のプラズマ膜カップは,CHO細胞では稀である.
- ディブチリルcAMPおよびマイクロチューブル破壊剤は,ピノサイトーシスの優位性に影響しません.
- サイトカラーシンBはConAの吸収を阻害し,表面の集積 (ミニキャップ) を促進する.
結論:
- CHO細胞は,キャピングではなく,直接のピノサイトーシスによって,主にConAを内蔵する.
- キャピングは,リンパ球のような低内細胞率の細胞で発生する可能性があります.
- サイトカラーシンBは,膜集積と直接内部化との間の競争を明らかにします.
関連する概念動画
Receptor-mediated Endocytosis
Overview
Endocytosis
Eukaryotic cells acquire nutrients for growth and proliferation. Nutrients and other molecules that require degradation are internalized from the extracellular space by a process called endocytosis. The term ‘endocytosis' was first coined by Christian de Duve in 1963.
Endocytosis always begins with the plasma membrane enclosing an incoming molecule to form a transport vesicle which, in some cases, can be coated with a protein called ‘clathrin.' Endocytosed material is either sorted through...
Endocytosis always begins with the plasma membrane enclosing an incoming molecule to form a transport vesicle which, in some cases, can be coated with a protein called ‘clathrin.' Endocytosed material is either sorted through...
Receptor-mediated Endocytosis
Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
The Early Endosome: Endocytosis of Transferrin
Essential proteins such as insulin or low-density lipoprotein (LDL) and micronutrients such as iron enter a eukaryotic cell through receptor-mediated endocytosis. Subsequently, the early endosomes fuse with the vesicles containing such receptor-ligand complexes and play a vital role in sorting the incoming ligands and receptors. While the ligands are either degraded inside the vesicle or released into the cytosol, their receptors are returned to the plasma membrane for further rounds of...
GPI Anchoring of Proteins in the ER Membrane
GPI-anchoring is a post-translational, reversible protein modification that is ubiquitous in eukaryotes. Such proteins are primarily present on the exoplasmic leaflet of the plasma membrane.
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...


