Interaction of Mint2 with TrkA Is Involved in Regulation of Nerve Growth Factor-induced Neurite Outgrowth

Yong Zhang,Yong-Gang Wang,Qi Zhang,Xiu-Jie Liu,Xuan Liu,Li Jiao,Wei Zhu,Zhao-Huan Zhang,Xiao-Lin Zhao,Cheng He

doi:10.1074/jbc.m809214200

Abstract

TrkA receptor signaling is essential for nerve growth factor (NGF)-induced survival and differentiation of sensory neurons. To identify possible effectors or regulators of TrkA signaling, yeast two-hybrid screening was performed using the intracellular domain of TrkA as bait. We identified muc18-1-interacting protein 2 (Mint2) as a novel TrkA-binding protein and found that the phosphotyrosine binding domain of Mint2 interacted with TrkA in a phosphorylation- and ligand-independent fashion. Coimmunoprecipitation assays showed that endogenous TrkA interacted with Mint2 in rat tissue homogenates, and immunohistochemical evidence revealed that Mint2 and TrkA colocalized in rat dorsal root ganglion neurons. Furthermore, Mint2 overexpression inhibited NGF-induced neurite outgrowth in both PC12 and cultured dorsal root ganglion neurons, whereas inhibition of Mint2 expression by RNA interference facilitated NGF-induced neurite outgrowth. Moreover, Mint2 was found to promote the retention of TrkA in the Golgi apparatus and inhibit its surface sorting. Taken together, our data provide evidence that Mint2 is a novel TrkA-regulating protein that affects NGF-induced neurite outgrowth, possibly through a mechanism involving retention of TrkA in the Golgi apparatus.

Highlights

The neurotrophin family member nerve growth factor (NGF)3 is essential for proper development, patterning, and maintenance of nervous systems [1, 2]
We identified muc18-1-interacting protein 2 (Mint2) as a novel TrkA-binding protein and found that the phosphotyrosine binding domain of Mint2 interacted with TrkA in a phosphorylation- and ligand-independent fashion
Structural studies have suggested that the interaction between the C-terminal tail and the PDZ domains of Mint1 has an important regulatory role in the function of Mint1 [54], it was demonstrated here by both yeast twohybrid and glutathione S-transferase (GST) pulldown assay that the phosphotyrosine binding (PTB) domain alone was necessary and sufficient for mediating the interaction of Mint2 with the intracellular domain of TrkA

Summary

Introduction

The neurotrophin family member nerve growth factor (NGF) is essential for proper development, patterning, and maintenance of nervous systems [1, 2]. MAY 1, 2009 VOLUME 284 NUMBER 18 rosines become docking sites for adaptor proteins involved in signal transduction pathways that lead to the activation of Ras, Rac, phosphatidylinositol 3-kinase, phospholipase C␥, and other effectors [2, 6] Many of these TrkA-interacting adaptor proteins have been identified and include, Grb, APS, SH2B, fibroblast growth factor receptor substrate 2 (FRS-2), Shc, and human tumor imaginal disc 1 (TID1) [7,8,9,10]. The identification of these binding partners has contributed greatly to our understanding of the mechanisms underlying the functional diversity of NGF-TrkA signaling. The mechanisms by which Mints inhibit ␤-APP processing are not yet well known, Mints and their binding partners have emerged as potential therapeutic targets for the treatment of Alzheimer disease

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Results

Conclusion