title: The LG3 module of laminin-5 harbors a binding site for integrin alpha3beta1 that promotes cell adhesion, spreading, and migration.
abstract: Laminins are a family of extracellular matrix glycoproteins involved in cell adhesion and migration. A major obstacle to understanding their structure-function relationships is the lack of small laminin domains capable of replicating integrin-binding, cell-adhesive, and migratory functions of the intact molecule. Here, we show that the recombinant LG3 (rLG3) module (26 kDa) of laminin-5 (Ln-5) alpha(3) chain replicated key Ln-5 activities. rLG3 but not rLG1 or rLG2 supported cell adhesion and migration of at least two distinct cell lines, in an integrin alpha(3)beta(1)-dependent manner. Cell adhesion to rLG3 was regulated by divalent cations and accompanied by cell spreading and tyrosine phosphorylation of FAK focal adhesion kinase. The integrin binding activity of rLG3 was confirmed by rLG3 affinity chromatography of detergent cell lysates, which resulted in specific purification of integrin alpha(3)beta(1). To our knowledge, this is the first report directly demonstrating that a recombinant laminin LG module is an active domain capable of supporting integrin-dependent cell adhesion and migration.
authors.affiliation: Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: M
authors.initials: M
authors.lastname: Shang
authors.forename: N
authors.initials: N
authors.lastname: Koshikawa
authors.forename: S
authors.initials: S
authors.lastname: Schenk
authors.forename: V
authors.initials: V
authors.lastname: Quaranta
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002413:Cations, Divalent / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002942:Circular Dichroism; D005354:Fibrosarcoma; D015723:Gene Library; D006801:Humans; D039201:Integrin alpha3beta1; D016023:Integrins / Q000737:chemistry* / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D011487:Protein Conformation; D021122:Protein Subunits; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured; D000097794:Kalinin
chemical_list: D002413:Cations, Divalent; D015815:Cell Adhesion Molecules; D039201:Integrin alpha3beta1; D016023:Integrins; D010446:Peptide Fragments; D021122:Protein Subunits; D011994:Recombinant Proteins; D000097794:Kalinin