Domain IVa of laminin alpha5 chain is cell-adhesive and binds beta1 and alphaVbeta3 integrins through Arg-Gly-Asp.
The globular domain IVa from the short arm region of mouse laminin alpha5 chain was obtained by recombinant production and shown to be a cell-adhesive substrate and to bind alphaVbeta3 integrin in solid-phase assays. These interactions were blocked by RGD peptides and a restricted panel of anti-integrin antibodies. The two RGD sequences present in alpha5IVa were shown by site-directed mutagenesis to make different contributions to cell adhesion but were equivalent in binding alphaVbeta3 integrin. A quantitative radioimmuno-inhibition assay was established based on domain alpha5IVa which demonstrated distinct amounts of alpha5 chain in various tissues, particularly in vessel walls. There it could play a role in angiogenesis steps requiring RGD-dependent integrins.
Sasaki
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Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152, Martinsried, Germany. sasaki@biochem.mpg.de
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D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D007668:Kidney / Q000166:cytology; D007797:Laminin / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008546:Melanoma, Experimental; D051379:Mice; D018482:Muscle, Skeletal / Q000166:cytology; D009842:Oligopeptides / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017434:Protein Structure, Tertiary; D019030:Receptors, Vitronectin / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D015815:Cell Adhesion Molecules; D019012:Integrin beta1; D007797:Laminin; D009842:Oligopeptides; D010446:Peptide Fragments; D019030:Receptors, Vitronectin; D011994:Recombinant Proteins; C097043:laminin alpha5; C047981:arginyl-glycyl-aspartic acid