The EIIIA Segment of Fibronectin Is a Ligand for Integrins α9β1 and α4β1Providing a Novel Mechanism for Regulating Cell Adhesion by Alternative Splicing

摘要: Abstract Alternative splicing of the fibronectin gene transcript gives rise to forms that include EIIIA (or ED-A) segment. EIIIA-containing fibronectins are prominently expressed during embryogenesis and wound healing appear mediate changes in cell adhesion expression. Nonetheless, integrins bind segment have not been identified. We previously mapped epitope for two function-blocking monoclonal antibodies C-C′ loop region (Liao, Y.-F., Wieder, K. G., Classen, J. M., Van De Water, L. (1999) Biol. Chem. 274, 17876–17884). The sequence this (39PEDGIHELFP48) resembles within tenascin-C which integrin α9β1binds. now report either α9β1 or α4β1can Moreover, interaction is blocked both by epitope-mapped as well respective anti-integrins. Deletion mutants flanking cells expressing α4β1. Adhesion α4β1-containing MOLT-3 stimulates phosphorylation p44/42 MAP kinase. Our observation establishes a novel mechanism regulated alternative splicing.