Neurite growth-promoting protein (amphoterin, p30) binds syndecan.
A new ligand for syndecan (a cell surface heparan sulfate-rich proteoglycan) has been discovered. In the solid-phase binding assay utilizing small nitrocellulose discs to immobilize matrix molecules, binding of syndecan to neurite growth-promoting protein, p30/amphoterin, was observed. This binding was strongly dependent on the concentration of amphoterin used to coat the discs, but was saturable with an excess amount of syndecan. The interaction was inhibitable with heparan sulfate and heparin but less effectively with chondroitin sulfate, indicating that heparan sulfate chains of syndecan were involved in the binding. Anti-amphoterin antibodies inhibited the binding partially. Mouse mammary epithelial cells were shown to bind amphoterin directly but not after trypsin treatment or in the presence of heparin and to produce amphoterin in the extracellular space. Both syndecan and amphoterin were found to localize on lateral surfaces of newly adhered mammary epithelial cells. Toward confluency amphoterin amounts decreased. Because amphoterin can be localized to the same sites with syndecan and because of their interaction, amphoterin is a new putative pericellular ligand for syndecan. These interactions may be involved in the regulation of cell behavior.
Department of Medical Biochemistry, University of Turku, Finland.
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Salmivirta
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Rauvala
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Elenius
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Jalkanen
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D024243:HMGB1 Protein; D006493:Heparin / Q000494:pharmacology; D006497:Heparan Sulfate / Q000494:pharmacology; D006609:High Mobility Group Proteins / Q000378:metabolism*; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011509:Proteoglycans / Q000378:metabolism*; D053667:Syndecans; D014357:Trypsin / Q000494:pharmacology
D002352:Carrier Proteins; D024243:HMGB1 Protein; D006493:Heparin; D006497:Heparan Sulfate; D006609:High Mobility Group Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D011509:Proteoglycans; D053667:Syndecans; D014357:Trypsin