Functional regulation of the human integrin VLA-1 (CD49a/CD29) by divalent cations and stimulatory beta 1 antibodies.
We have investigated the regulation by divalent cations Mg2+, Ca2+ and Mn2+ of the functional activity of the human integrin VLA-1 expressed on neuroblastoma NB100 cells. VLA-1-mediated adhesion of NB100 cells to ligand collagen type I was supported by either mM concentrations of extracellular Mg2+ or microM levels of Mn2+. In contrast, Ca2+ alone did not induce activation of VLA-1 but exerted a potent inhibitory effect on the Mg(2+)-supported cell adhesion. We have also demonstrated that VLA-1 can be directly activated by the stimulatory monoclonal antibody TS2/16 specific for the integrin beta 1 subunit, resulting in effective adhesion of NB100 cells to type I collagen. This study has been possible by using a novel blocking VLA-alpha 1 specific monoclonal antibody, 5E8D9.
Luque
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Departamento de Bioquímica, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Sánchez-Madrid
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Cabañas
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C
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent; D002448:Cell Adhesion / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D006801:Humans; D007163:Immunosorbent Techniques; D019012:Integrin beta1; D016023:Integrins / Q000276:immunology / Q000502:physiology; D007797:Laminin / Q000378:metabolism; D046911:Macromolecular Substances; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008545:Melanoma / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism; D016029:Receptors, Very Late Antigen / Q000276:immunology / Q000502:physiology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D002413:Cations, Divalent; D019012:Integrin beta1; D016023:Integrins; D007797:Laminin; D046911:Macromolecular Substances; D016029:Receptors, Very Late Antigen; D008345:Manganese; D003094:Collagen; D008274:Magnesium; D002118:Calcium