マツイ　タケシ   Takeshi Matsui   松井　毅    所属   応用生物学部 応用生物学科    職種   教授
言語種別	英語
発行・発表の年月	2004/10
形態種別	学術論文
査読	査読あり
標題	Establishment and characterization of cultured epithelial cells lacking expression of ZO-1
執筆形態	共著
掲載誌名	Journal of Biological Chemistry
掲載区分	国外
出版社・発行元	ELSEVIER
巻・号・頁	279(43),pp.44785-44794
著者・共著者	Kazuaki Umeda, Takeshi Matsui, Mayumi Nakayama, Kyoko Furuse, Hiroyuki Sasaki, Mikio Furuse, Shoichiro Tsukita
概要	n well polarized epithelial cells, closely related ZO-1 and ZO-2 are thought to function as scaffold proteins at tight junctions (TJs). In epithelial cells at the initial phase of polarization, these proteins are recruited to cadherin-based spotlike adherens junctions (AJs). As a first step to clarify the function of ZO-1, we successfully generated mouse epithelial cell clones lacking ZO-1 expression (ZO-1-/- cells) by homologous recombination. Unexpectedly, in confluent cultures, ZO-1-/- cells were highly polarized with well organized AJs/TJs, which were indistinguishable from those in ZO-1+/+ cells by electron microscopy. In good agreement, by immunofluorescence microscopy, most TJ proteins including claudins and occludin appeared to be normally concentrated at TJs of ZO-1-/- cells with the exception that a ZO-1 deficiency significantly up- or down-regulated the recruitment of ZO-2 and cingulin, another TJ scaffold protein, respectively, to TJs. When the polarization of ZO-1-/- cells was initiated by a Ca2+ switch, the initial AJ formation did not appear to be affected; however, the subsequent TJ formation (recruitment of claudins/occludin to junctions and barrier establishment) was markedly retarded. This retardation as well as the disappearance of cingulin were rescued completely by exogenous ZO-1 but not by ZO-2 expression. Quantitative evaluation of ZO-1/ZO-2 expression levels led to the conclusion that ZO-1 and ZO-2 would function redundantly to some extent in junction formation/epithelial polarization but that they are not functionally identical. Finally, we discussed advantageous aspects of the gene knock-out system with cultured epithelial cells in epithelial cell biology.