title: Isolation and activity of proteolytic fragment of laminin-5 alpha3 chain.
abstract: Laminin-5 (alpha3beta3gamma2) is an important component of epithelial basement membranes. The 190-kDa alpha3 chain undergoes extracellular cleavage within the carboxyl (C) terminus consisting of five globular domains (G1 to G5), producing the mature laminin-5 with the 160-kDa alpha3 chain. To understand the physiological meaning of this processing, we isolated the C-terminal fragments of the alpha3 chain from the conditioned media of two kinds of human cell lines. The amino-terminal sequence of the fragments suggested that the cleavage occurs at Gln(1337)-Asp(1338) in the spacer region between the G3 and G4 domains. The G4-G5 fragment itself did not show significant activity, but it stimulated cell migration in the presence of a low concentration of the mature laminin-5, suggesting its regulatory role in cell migration.
authors.affiliation: Division of Cell Biology, Graduate School of Integrated Sciences, Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, 244-0813, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsubota
authors.forename: H
authors.initials: H
authors.lastname: Mizushima
authors.forename: T
authors.initials: T
authors.lastname: Hirosaki
authors.forename: S
authors.initials: S
authors.lastname: Higashi
authors.forename: H
authors.initials: H
authors.lastname: Yasumitsu
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000502:physiology*; D002460:Cell Line; D017077:Culture Media, Conditioned; D006801:Humans; D015603:Keratinocytes; D007797:Laminin / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D017077:Culture Media, Conditioned; D007797:Laminin; D010446:Peptide Fragments; D000097794:Kalinin; C095567:laminin alpha 3