1 0 0 0 OA アクチン結合蛋白質エズリンの上皮機能調節、神経ネットワーク構築における役割の解明
アクチン結合タンパク質であるエズリンは,細胞内で膜タンパク質と細胞骨格とを有機的に連結して,上皮細胞の頂端膜や神経組織の形態形成に働く。近年になって,エズリンが特定の膜輸送タンパク質や接着分子の細胞表面へのターゲッティングに関わることが明らかにされた。本研究では,エズリン遺伝子を改変したノックダウンマウスなどを用いて,主に動物個体におけるエズリンの上皮組織構築,上皮輸送調節や,神経細胞の突起形成やネットワーク形成における役割を検討した。その結果,エズリンが腎尿細管におけるリンの再吸収や,胆管細胞における胆汁の修飾や流量調節,また神経細胞における突起形成に関わることを見出した。
1 0 0 0 OA 胃壁細胞における胃酸分泌の分子基盤
- 著者
- 浅野 真司
- 出版者
- 日本膜学会
- 雑誌
- 膜 (ISSN:03851036)
- 巻号頁・発行日
- vol.36, no.6, pp.278-285, 2011 (Released:2012-05-18)
- 参考文献数
- 35
- 被引用文献数
- 1
Gastric acid secretion in parietal cells is performed by proton pump, H+, K+- ATPase, in combination with several related ion transporters located on the apical and basolateral membranes. In this review I will introduce several recent topics about molecular basis of gastric acid secretion in parietal cells. First, I wish to introduce 3D structures of H+, K+-ATPase resolved recently. The structures demonstrated the interaction between the α- and β- subunits fixes and favors the E2P conformation (the “rachet effect”). The binding site of a K+-competitive inhibitor SCH 28080 on the α- subunit of H+, K+-ATPase was also identified in the 3D structure. Secondly, I wish to introduce ion transporters on the apical membrane necessary for gastric acid secretion. Among others KCNQ1/KCNE2 was identified as a K+ channel involved in K+ recycling and replenishment of K+ in the lumen. Thirdly, I wish to introduce actin-binding proteins, ezrin and Huntingtin interacting protein 1 related (Hip1r), which are necessary for gastric acid secretion. Ezrin is involved in membrane fusion between tubulovesicles and apical membrane whereas Hip1r is involved in endocytosis and regeneration of tubulovesicles from apical membrane. Finally, the roles of parietal cells in differentiation of gastric epithelial cells as well as gastric acid secretion will be introduced.