Tissue fibronectin is an endogenous ligand for galectin-1

• Published in: Glycobiology (Oxford) 1995-03, Vol.5 (2), p.255-261
• Main Authors: Ozeki, Yasuhiro, Matsui, Taei, Yamamoto, Yoshinobu, Funahashi, Masanori, Hamako, Jiharu, Titani, Koiti
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal; Antineoplastic Agents - pharmacology; Blotting, Western; Cell Adhesion; Chromatography, Affinity; Electrophoresis, Polyacrylamide Gel; extracellular matrix; Female; fibronectin; Fibronectins - isolation & purification; Fibronectins - metabolism; galectin; Galectin 1; Hemagglutinins - chemistry; Hemagglutinins - isolation & purification; Hemagglutinins - metabolism; Humans; laminin; Laminin - isolation & purification; Laminin - metabolism; Lectins - isolation & purification; Lectins - metabolism; Molecular Weight; Oligopeptides - pharmacology; Ovum - metabolism; placenta; Placenta - metabolism; Pregnancy; Protein Binding; Rana catesbeiana
• ISSN: 0959-6658; 1460-2423
• DOI: 10.1093/glycob/5.2.255

A 14K β-galactoside-binding lecttn (galectin-1) is present in many animal tissues. In a search for endogenous ligands, we surveyed galectin-1-binding proteins in human placenta. Extract of human placenta with 2 M urea was applied to a Sepharose 4B column conjugated with galectin-1 purified from frog (Rana catesbeiana) eggs. Two major proteins eluted with 100 mM lactose from the column-bound fraction showed apparent molecular masses of 220 and 180 kDa on SDS-PAGE under reducing conditions. Western blotting analysis using monoclonal antibodies indicated that these proteins were fibronectin and laminin, respectively. Most placenta] and amniotic fibronectins bound strongly to the column, whereas almost all plasma fibronectin passed through the column. The galectin-1, fibronectin and laminin were immunohistochemically shown to be co-localized in the extracellular matrix of placental tissue. In a cell attachment assay, rhabdosarcoma cells adhered to a plate coated with placental fibronectin, even in the presence of GRGDS peptide, if galectin-1 were also present This adhesive effect of galectin-1 was inhibited by lactose. These results indicate that tissue fibronectin, as well as laminin, serve as endogenous ligands for galectin-1, suggesting that galectin-1 may play a role in assembly of the extracellular matrix, or in the control of cell adhesion based on lectin-extracellular matrix interaction.