分泌されるタンパク質の偏離された分類のpHに依存する
M J Caplan1, J L Stow, A P Newman
1Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510.
Nature
|October 15, 1987
まとめ
皮質細胞は,タンパク質を特定の膜領域に精密に分類する. 犬腎管 (MDCK) 細胞は,ラミニンやヘパラン硫酸プロテオグリカン (HSPG) のような基礎膜の成分を,基礎側からの放出のために積極的に分類し,酸性細胞内環境を必要とします.
科学分野:
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
背景:
- 皮質細胞は,異なる頂上および底辺のプラズマ膜領域を有しています.
- このドメインの専門化は,膜タンパク質の標的の配送と製品の極化分泌を可能にします.
- 犬腎管 (MDCK) 細胞は,上皮の極性およびタンパク質の分類を研究するためのモデルシステムです.
研究 の 目的:
- MDCK細胞による基礎膜成分の極化分泌の背後にあるメカニズムを調査する.
- ラミニンとヘパラン硫酸プロテオグリカン (HSPG) の放出が積極的に分類されているか,またはデフォルトの経路に従っているかどうかを判断する.
- 分泌タンパク質の極化分類に関与する細胞内コンパートメントを特定する.
主な方法:
- MDCK細胞を用いて,基礎膜成分の分泌を研究した.
- アンモニアム塩化物 (NH4Cl) を用いて細胞内pHを操作し,酸性コンパートメントを破壊する.
- ラミニンとHSPGの頂上部と下部側部への放出量を定量化しました.
主要な成果:
- 基礎膜の成分であるラミニンとヘパラン硫酸タンパク質グリカン (HSPG) は,主にMDCK細胞の底側表面から分泌されます.
- この偏光分泌は,活発な分類プロセスである.
- NH4Clによる酸性細胞内コンパートメントの破壊は,ラミニンとHSPGの極化していない分泌をアピカルおよびベースラテラルメディアの両方に導いた.
結論:
- MDCK細胞による基礎膜成分の極化分泌は,アクティブソートメカニズムによって媒介されます.
- この分類プロセスには,酸性細胞内コンパートメントが不可欠です.
- 機能的な酸性コンパートメントがない場合,タンパク質はデフォルトの経路で分泌され,その結果,非極化放出が起こります.
関連する概念動画
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