PMID: 20739287

Authors:

Deshmukh L, Gorbatyuk V, Vinogradova O

Title:

Integrin beta3 phosphorylation dictates its complex with Shc PTB domain.

Journal:

J Biol Chem. 2010 Aug 25.

Abstract:

Adaptor protein Shc plays a key role in mitogen-activated protein kinase (MAPK) signaling pathway, which can be mediated through a number of different receptors including integrins. By specifically recognizing the tyrosine phosphorylated integrin beta3, Shc has been shown to trigger integrin outside-in signaling, although the structural basis of this interaction remains nebulous. Here we present the detailed structural analysis of Shc Phosphotyrosine Binding (PTB) domain in complex with the bi-phosphorylated beta3 integrin cytoplasmic tail (CT). We show that this complex is primarily defined by the phosphorylation state of the integrin C-terminal 759Y, which fits neatly into the classical PTB pocket of Shc. In addition, we have identified a novel binding interface which concurrently accommodates phosphorylated 747Y of the highly conserved NPxY motif of beta3. The structure represents the first snapshot of an integrin cytoplasmic tail bound to a target for mediating the outside-in signaling. Detailed comparison with the known Shc PTB structure bound to a target TrkA peptide revealed some significant differences, which shed new light upon the PTB domains' specificity.