title: Disulfide-bonding between Drosophila laminin beta and gamma chains is essential for alpha chain to form alpha betagamma trimer.
abstract: Assembly of Drosophila laminin alpha, beta and gamma chains was analyzed by immunoprecipitation of the lysate from metabolically radiolabeled Kc 167 cells with chain-specific antibodies followed by two dimensional electrophoresis in which non-reducing and reducing SDS gel electrophoresis are combined. Precipitation of monomeric beta (or gamma) with anti-gamma (or -beta) antibody revealed that beta and gamma form stable dimer before they are disulfide-bonded to each other. In contrast, alpha associates with neither monomeric beta, monomeric gamma nor betagamma dimer without disulfide-bonding but only with disulfide-bonded betagamma dimer to form alpha betagamma trimers. These results thus demonstrated that the interchain disulfide-boding between beta and gamma is essential for alpha to form alpha betagamma trimer. We also found that the alpha betagamma trimer can be secreted with alpha chain either disulfide-bonded or not bonded to the disulfide-bonded betagamma dimer.
authors.affiliation: Graduate Program for Biochemical Regulation, Graduate School of Agricultural Sciences, Chikusa-ku, Nagoya, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Kumagai
authors.forename: T
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000737:chemistry; D002460:Cell Line; D019281:Dimerization; D004220:Disulfides / Q000378:metabolism*; D004330:Drosophila / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D015151:Immunoblotting; D007163:Immunosorbent Techniques; D007797:Laminin / Q000737:chemistry* / Q000378:metabolism*; D046911:Macromolecular Substances; D008623:Mercaptoethanol / Q000494:pharmacology
chemical_list: D004220:Disulfides; D007797:Laminin; D046911:Macromolecular Substances; D008623:Mercaptoethanol