title: Membrane microdomains from early gastrula embryos of medaka, Oryzias latipes, are a platform of E-cadherin- and carbohydrate-mediated cell-cell interactions during epiboly.
abstract: Formation of membrane microdomain is critical for cell migration (epiboly) during gastrulation of medaka fish [Adachi et al. (Biochem. Biophys. Res. Commun. 358:848-853, 2007)]. In this study, we characterized membrane microdomain from gastrula embryos to understand its roles in epiboly. A cell adhesion molecule (E-cadherin), its associated protein (beta-catenin), transducer proteins (PLCgamma, cSrc), and a cytoskeleton protein (beta-actin) were enriched in the membrane microdomain. Le(X)-containing glycolipids and glycoproteins (Le(X)-gp) were exclusively enriched in the membrane microdomain. Interestingly, the isolated membrane microdomain had the ability to bind to each other in the presence of Ca(2+). This membrane microdomain binding was achieved through the E-cadherin homophilic and the Le(X)-glycan-mediated interactions. E-cadherin and Le(X)-gp were co-localized on the same membrane microdomain, suggesting that these two interactions are operative at the same time. Thus, the membrane microdomain functions as a platform of the E-cadherin- and Le(X)-glycan-mediated cell adhesion and signal transduction.
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, 464-8601, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Adachi
authors.forename: Chihiro
authors.initials: C
authors.lastname: Sato
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kishi
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Totani
authors.forename: Takeomi
authors.initials: T
authors.lastname: Murata
authors.forename: Taichi
authors.initials: T
authors.lastname: Usui
authors.forename: Ken
authors.initials: K
authors.lastname: Kitajima