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	1998
形態種別	学術論文
査読	査読あり
標題	Rho-kinase phosphorylates COOH-terminal threonines of ezrin/radixin/moesin (ERM) proteins and regulatestheir head-to-tail association
執筆形態	共著
掲載誌名	Journal of Cell Biology
掲載区分	国外
出版社・発行元	Rockefeller University Press
巻・号・頁	140(3),pp.647-657
総ページ数	11
担当区分	筆頭著者
著者・共著者	Takeshi Matsui, Masato Maeda, Yoshinori Doi, Shigenobu Yonemura, Mutsuki Amano, Kozo Kaibuchi, Sachiko Tsukita, Shoichiro Tsukita
概要	The ezrin/radixin/moesin (ERM) proteins are involved in actin filament/plasma membrane inter- action that is regulated by Rho. We examined whether ERM proteins are directly phosphorylated by Rho- associated kinase (Rho-kinase), a direct target of Rho. Recombinant full-length and COOH-terminal half radixin were incubated with constitutively active catalytic domain of Rho-kinase, and ~30 and ~100% of these molecules, respectively, were phosphorylated mainly at the COOH-terminal threonine (T564). Next, to detect Rho-kinase–dependent phosphorylation of ERM pro- teins in vivo, we raised a mAb that recognized the T564-phosphorylated radixin as well as ezrin and moesin phosphorylated at the corresponding threonine residue (T567 and T558, respectively). Immunoblotting of serum-starved Swiss 3T3 cells with this mAb re- vealed that after LPA stimulation ERM proteins were rapidly phosphorylated at T567 (ezrin), T564 (radixin), and T558 (moesin) in a Rho-dependent manner and then dephosphorylated within 2 min. Furthermore, the T564 phosphorylation of recombinant COOH-termi- nal half radixin did not affect its ability to bind to actin filaments in vitro but significantly suppressed its direct interaction with the NH2-terminal half of radixin. These observations indicate that the Rho-kinase–dependent phosphorylation interferes with the intramolecular and/ or intermolecular head-to-tail association of ERM pro- teins, which is an important mechanism of regulation of their activity as actin filament/plasma membrane cross- linkers.