title: Integrin {beta}3 phosphorylation dictates its complex with the Shc phosphotyrosine-binding (PTB) domain.
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 β(3), 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 β(3)integrin cytoplasmic tail (CT). We show that this complex is primarily defined by the phosphorylation state of the integrin C-terminal Tyr(759), which fits neatly into the classical PTB pocket of Shc. In addition, we have identified a novel binding interface which concurrently accommodates phosphorylated Tyr(747) of the highly conserved NPXY motif of β(3). 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 domain specificity.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, Connecticut 06269-3092, USA.
authors.forename: Lalit
authors.initials: L
authors.lastname: Deshmukh
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Gorbatyuk
authors.forename: Olga
authors.initials: O
authors.lastname: Vinogradova
mesh_terms: D006801:Humans; D039661:Integrin beta3 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D055765:Shc Signaling Adaptor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D039661:Integrin beta3; D046912:Multiprotein Complexes; D010455:Peptides; D055765:Shc Signaling Adaptor Proteins; D019000:Phosphotyrosine