title: Suppression of Rac1 activity at the apical membrane of MDCK cells is essential for cyst structure maintenance.
abstract: Using MDCK cells that constitutively express a Förster resonance energy transfer biosensor, we found that Rac1 activity is homogenous at the entire plasma membrane in early stages of cystogenesis, whereas in later stages Rac1 activity is higher at the lateral membrane than at the apical plasma membrane. If Rac1 is activated at the apical membrane in later stages, however, the monolayer cells move into the luminal space. In these cells, tight junctions are disrupted, accompanied by mislocalization of polarization markers and disorientation of cell division. These observations indicate that Rac1 suppression at the apical membrane is essential for the maintenance of cyst structure.
authors.affiliation: Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Yoshida Konoe-cho, Kyoto 606-8501, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yagi
authors.forename: Michiyuki
authors.initials: M
authors.lastname: Matsuda
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kiyokawa
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity; D003560:Cysts / Q000378:metabolism*; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D020830:rac1 GTP-Binding Protein