title: Involvement of the Ras-Ras-activated Rab5 guanine nucleotide exchange factor RIN2-Rab5 pathway in the hepatocyte growth factor-induced endocytosis of E-cadherin.
abstract: E-cadherin is a key cell-cell adhesion molecule at adherens junctions (AJs) and undergoes endocytosis when AJs are disrupted by the action of an extracellular signal, such as hepatocyte growth factor (HGF)/scatter factor. Rab5 small G protein has been implicated in the HGF-induced endocytosis of E-cadherin, but the molecular mechanism for the regulation of Rab5 activity remains unknown. We first studied this mechanism by using the cell-free assay system for the endocytosis of E-cadherin of the AJ-enriched fraction from rat livers. HGF induced activation of Ras small G protein, which then bound to RIN2, a Rab5 GDP/GTP exchange factor with the Vps9p-like guanine nucleotide exchange factor and Ras association domains, and activated it. Activated RIN2 then activated Rab5, eventually inducing the endocytosis of E-cadherin. We then studied whether RIN2 was involved in the HGF-induced endocytosis of E-cadherin in intact Madin-Darby canine kidney cells. RIN2 localized at the cell-cell adhesion sites, and its guanine nucleotide exchange factor activity was required for the HGF-induced endocytosis of E-cadherin in Madin-Darby canine kidney cells. These results indicate that RIN2 connects Ras to Rab5 in the HGF-induced endocytosis of E-cadherin.
authors.affiliation: Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita 565-0871, Osaka, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kimura
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Sakisaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Baba
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000818:Animals; D015820:Cadherins / Q000737:chemistry* / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004705:Endocytosis; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry*; D017228:Hepatocyte Growth Factor / Q000378:metabolism*; D008954:Models, Biological; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014162:Transfection; D033921:Vesicular Transport Proteins / Q000378:metabolism; D020696:rab5 GTP-Binding Proteins / Q000737:chemistry*; D020663:ras Guanine Nucleotide Exchange Factors / Q000737:chemistry* / Q000502:physiology*
chemical_list: D015820:Cadherins; D002352:Carrier Proteins; D020662:Guanine Nucleotide Exchange Factors; C447829:RIN2 protein, human; D029701:Saccharomyces cerevisiae Proteins; C099285:VPS9 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D020663:ras Guanine Nucleotide Exchange Factors; D017228:Hepatocyte Growth Factor; D005982:Glutathione Transferase; D020696:rab5 GTP-Binding Proteins