journal article

Journal Article

Text

Journal of Biological Chemistry. 2001, 276(20), p. 17550-17558

Purification and Characterization of Human Laminin-8 : LAMININ-8 STIMULATES CELL ADHESION AND MIGRATION THROUGH α3β1 AND α6β1INTEGRINS

American Society for Biochemistry and Molecular Biology

English

Text

2001-05

https://doi.org/10.1074/jbc.M010155200

This research was originally published in the Journal of Biological Chemistry. Hironobu Fujiwara, Yamato Kikkawa, Noriko Sanzen and Kiyotoshi Sekiguchi. Purification and Characterization of Human Laminin-8 : LAMININ-8 STIMULATES CELL ADHESION AND MIGRATION THROUGH α3β1 AND α6β1INTEGRINS. J. Biol. Chem. 2001; 276: 17550-17558 © the American Society for Biochemistry and Molecular Biology

Recently identified laminin isoforms containing the α4 chain have been shown to be expressed in the basement membrane of restricted organs such as heart, skeletal muscle, and blood vessels, especially those in embryos. We screened 38 human cell lines for the expression of the laminin α4 chain by reverse transcriptase-polymerase chain reaction and found that T98G glioblastoma cells express only α4, but not other α chains. Laminin-8, an isoform containing the α4 and β1 chains, was purified from conditioned medium of T98G cells by gel filtration and immunoaffinity chromatography using a monoclonal antibody against laminin β1 chain. The purified laminin isoform was composed of disulfide-linked 230-, 220-, and 200-kDa subunits, which immunoblot analysis identified as the β1, γ1, and α4 chains. Purified laminin-8 had cell adhesive activity comparable to laminin-1 but significantly weaker than laminin-5 and laminin-10/11. T98G cells adhering to laminin-8 became more elongated than those adhering to other laminin isoforms and extended multiple pseudopods. Cell adhesion to laminin-8 was abolished by an antibody against the integrin β1 subunit or a combination of antibodies against the integrin α3 and α6 subunits, but not by either anti-α3 or anti-α6 antibody alone, suggesting that both α3β1 and α6β1 integrins serve as adhesion receptors for laminin-8. Consistent with these observations, K562 erythroleukemic cells transfected with either integrin α3 or α6 cDNA were capable of adhering to laminin-8 when β1 integrins were stimulated by the β1-activating antibody 8A2. Despite its moderate cell adhesive activity, laminin-8 was significantly potent in promoting cell migration when compared with other laminin isoforms and fibronectin. Cell migration on laminin-8 was completely inhibited by a combination of antibodies against α3 and α6 integrins, and substantially inhibited by anti-α3 antibody alone, suggesting that laminin-8-mediated cell migration is predominantly mediated by α3β1 integrin. Given its potency to stimulate cell migration and preferential localization to the basement membrane of capillaries and embryonic tissues, laminin-8 may play a role in processes requiring enhanced cell migration during development, wound healing, and angiogenesis.

71437

Purification and Characterization of Human Laminin-8 : LAMININ-8 STIMULATES CELL ADHESION AND MIGRATION THROUGH α3β1 AND α6β1INTEGRINS

American Society for Biochemistry and Molecular Biology

English

2001-05

Journal of Biological Chemistry

276

20

17550

17558

https://doi.org/10.1074/jbc.M010155200

https://hdl.handle.net/11094/71437