PMID: 16455489 , Related PDB id: 2BRQ

Authors:

Kiema T, Lad Y, Jiang P, Oxley CL, Baldassarre M, Wegener KL, Campbell ID, Ylanne J, Calderwood DA

Title:

The molecular basis of filamin binding to integrins and competition with talin.

Journal:

Mol Cell. 2006 Feb 3;21(3):337-47.

Abstract:

The ability of adhesion receptors to transmit biochemical signals and mechanical force across cell membranes depends on interactions with the actin cytoskeleton. Filamins are large, actin-crosslinking proteins that connect multiple transmembrane and signaling proteins to the cytoskeleton. Here, we describe the high-resolution structure of an interface between filamin A and an integrin adhesion receptor. When bound, the integrin beta cytoplasmic tail forms an extended beta strand that interacts with beta strands C and D of the filamin immunoglobulin-like domain (IgFLN) 21. This interface is common to many integrins, and we suggest it is a prototype for other IgFLN domain interactions. Notably, the structurally defined filamin binding site overlaps with that of the integrin-regulator talin, and these proteins compete for binding to integrin tails, allowing integrin-filamin interactions to impact talin-dependent integrin activation. Phosphothreonine-mimicking mutations inhibit filamin, but not talin, binding, indicating that kinases may modulate this competition and provide additional means to control integrin functions.