MET and p66SHC interactomes and functions

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The integrity of the intestinal epithelium of the digestive tract is ensured by its rapid renewal. This involves spatiotemporal coordinated proliferation, migration, differentiation and survival of various intestinal epithelial cells (IEC). These cellular processes are dictated by growth factor signals produced by IECs and adjacent cells. Hepatocyte growth factor (HGF) is a molecule promoting and maintaining tissue organization in various organs by activating the receptor tyrosine kinase (RTK) MET in epithelial cells. Several lines of evidence suggest that the MET/HGF receptor axis may play a key role in the renewal of the intestinal epithelium, but the early embryonic death of HGF- or MET-deficient mice have greatly limited its study.******When activated, MET forms signaling multiprotein complexes that may relay downstream regulatory signals to a variety of biological processes. Our previous work identified that MET activation in cultured IECs stimulates several processes critical for the renewal of the intestinal epithelium. Moreover, we uncovered novel non-canonical dynamic mechanisms of interaction between MET and some of its interacting partners (most notably p66SHC), resulting in a variety of possible interaction complexes and biological outcomes affecting MET regulation of IEC survival, proliferation and migration.******Here, we propose to exploit the intestinal organoid technology combined with highly-sophisticated high-throughput screening methods to analyze the global and contextual MET multiprotein complexes in IEC. These studies will help understand the IEC-specific role of MET and its interacting partner p66SHC in the signaling network integration operating in the renewal of the intestinal epithelium. Intestinal organoids represent the most advanced in vitro system for molecular studies of the intestinal epithelium. Organoids closely replicate the intestinal epithelium organization as well as many of the biological processes involved on intestinal cells differentiation, function and renewal. ******Defining the dynamic spatiotemporal regulation of MET/p66SHC complexes in cells and the nature of their interactomes is bound to provide an unparalleled understanding of MET signaling and its contextual functions in the biology of IEC. These novel insights may also serve as a paradigm for a more generalized understanding of the signaling networks and functions of other RTKs, given that signaling by many RTKs follows the same general biological principles.