Interaction of filamin A with the integrin beta 7 cytoplasmic domain: role of alternative splicing and phosphorylation.

Integrin-filamin binding plays an important role in adhesion-mediated control of the actin cytoskeleton. Here, using the interaction between recombinant fragments from the C-terminus of filamin A and the cytoplasmic tail of integrin beta 7 as a model, we report a negative regulatory role for filamin alternative splicing. Splice variant forms of filamin A lacking a 41-amino acid segment interacted more strongly than full-length fragments. In addition, we provide evidence that phosphorylation of the splice variant region is unlikely to represent the mechanism by which binding is reduced.