title: Coendocytosis of cadherin and c-Met coupled to disruption of cell-cell adhesion in MDCK cells--regulation by Rho, Rac and Rab small G proteins.
abstract: Both E-cadherin, a cell-cell adhesion molecule, and c-Met, the hepatocyte growth factor (HGF)/scatter factor (SF) receptor, were colocalized at cell-cell adhesion sites of MDCK cells. HGF/SF or a phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), induced disruption of cell-cell adhesion, which was accompanied by endocytosis of both E-cadherin and c-Met. Reduction of medium Ca2+ to a micromolar range showed the same effects. Re-increase in medium Ca2+ to a millimolar range formed cell-cell adhesion, which was accompanied by exocytosis of E-cadherin and c-Met, followed by their re-colocalization at the cell-cell adhesion sites. These results suggest that E-cadherin and c-Met are colocalized at cell-cell adhesion sites and undergo co-endo-exocytosis. We have previously shown that TPA does not induce disruption of cell-cell adhesion and subsequent scattering of MDCK cells stably expressing a dominant active mutant of RhoA or Rac1 small G protein or a dominant negative mutant of Rab5 small G protein. In these cell lines, the HGF- or TPA-induced coendocytosis of E-cadherin and c-Met was inhibited, but the coendocytosis of E-cadherin and c-Met in response to reduction of medium Ca2+ was not affected. Wortmannin, an inhibitor of phosphoinositide (PI) 3-kinase, inhibited the HGF-induced disruption of cell-cell junction and endocytosis of E-cadherin and c-Met, but not the TPA-induced ones. These results suggest that disruption of cell-cell adhesion is involved in the HGF- or TPA-induced coendocytosis of E-cadherin and c-Met in MDCK cells, and that the Rho and Rab family members indirectly regulate this coendocytosis. In addition, coendocytosis of E-cadherin and c-Met in response to HGF is partly mediated by PI 3-kinase. The cross-talk between cell-cell and cell-matrix adherens junctions is discussed.
authors.affiliation: Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kamei
authors.forename: T
authors.initials: T
authors.lastname: Matozaki
authors.forename: T
authors.initials: T
authors.lastname: Sakisaka
authors.forename: A
authors.initials: A
authors.lastname: Kodama
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Y F
authors.initials: YF
authors.lastname: Peng
authors.forename: K
authors.initials: K
authors.lastname: Nakano
authors.forename: K
authors.initials: K
authors.lastname: Takaishi
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002460:Cell Line; D003470:Culture Media; D004285:Dogs; D004705:Endocytosis / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D015820:Cadherins; D003470:Culture Media; D004791:Enzyme Inhibitors; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium