Shc Binding to Nerve Growth Factor Receptor Is Mediated by the Phosphotyrosine Interaction Domain

Ivan Dikic,Andreas G Batzer,Pamela Blaikie,Axel Obermeier,Axel Ullrich,Joseph Schlessinger,Ben Margolis

doi:10.1074/jbc.270.25.15125

Abstract

Shc is an adaptor protein that contains two phosphotyrosine-binding domains, a Src homology 2 (SH2) domain and the newly described phosphotyrosine interaction (PI) domain. Shc interacts with several tyrosine-phosphorylated proteins and is itself tyrosine-phosphorylated in cells stimulated with a variety of growth factors and cytokines. Upon phosphorylation, Shc binds to the Grb2.Sos complex leading to the activation of the Ras signaling pathway. Mutational analysis of the nerve growth factor (NGF) receptor (TrkA) suggested that the binding of Shc to the activated receptor is required for NGF-induced neuronal differentiation of PC12 cells. Here we report that the PI domain of Shc directly binds to tyrosine 490 on the autophosphorylated NGF receptor. The PI domain specifically recognizes an I/LXN-PXpY motif (where p indicates phosphorylation) as determined by phosphopeptide competition assay. In addition, the PI domain is able to efficiently compete for binding of full-length Shc proteins to the NGF receptor. In PC12 cells, the Shc SH2 domain interacts with an unidentified tyrosine-phosphorylated protein of 115 kDa but not with the activated NGF receptor. The ability of Shc to interact with different tyrosine-phosphorylated proteins via its PI and SH2 domains may allow Shc to play a unique role in tyrosine kinase signal transduction pathways.

Highlights

Growth factors play an important role in controlling cell growth and differentiation
In the case of other growth factor receptors, such as NGF receptor (TrkA) or fibroblast growth factor receptor, the Grbz-Sos complex does not associate directly with the activated receptors, but binds to other tyrosine-phosphorylated proteins, such as She. She is an SH2 domain-containing adaptor protein that can bind to several growth factor receptors, including NGF receptor and EGFR, and is tyrosine-phosphorylated in cells stimulated with a variety of growth factors and cytokines [7,8,9,10,11,12,13,14]
She binding to tyrosine 490 of the NGF receptor has been shown to be required for the activation of the Ras signaling pathway and neuronal differentiation in PC12 cells [15, 16]. She binds to an NPXpY motif on several tyrosine-phosphorylated proteins [10,11,13,14,15,16,17,18]. This is an unusual motif for SH2 domain binding, since SH2 domains binding specificity is dictated by residues carboxyl-terminal to the phosphotyrosine moiety [2,3,4]

Summary

Introduction

Growth factors play an important role in controlling cell growth and differentiation. She binding to tyrosine 490 of the NGF receptor has been shown to be required for the activation of the Ras signaling pathway and neuronal differentiation in PC12 cells [15, 16]. We have recently identified a novel domain in She, encompassing amino acids 46-209 of the p52 Shc protein, and shown that it binds to activated growth factor receptors [19].

Results

Conclusion