Signaling through the epidermal growth factor receptor (EGFR) has critical roles in development and in diseases such as cancer. All ligands of the EGFR are made as membrane-anchored precursors whose ectodomain must be proteolytically released or "shed" to trigger EGFR-signaling. EGFR-ligand shedding is therefore crucial for EGFR- signaling. The membrane-anchored metalloproteinase ADAM17 has emerged as the principal regulator of the bioavailability of EGFR-ligands. Mice lacking ADAM17 phenotypically resemble those lacking the EGFR, providing unequivocal genetic evidence for the essential role of ADAM17 in EGFR signaling and establishing ADAM17 as an important potential target for the treatment of EGFR-dependent cancers. ADAM17 activity is highly regulated and is influenced by numerous signaling pathways. How these pathways functionally intersect with ADAM17 and how ADAM17 is activated are key questions that are the subject of this application. Our results show that a mutant of ADAM17 that lacks its cytoplasmic domain and therefore has no potential phosphorylation sites, responds normally to all physiological stimuli of ectodomain shedding tested to date. Moreover, substitution of the ADAM17 transmembrane domain (TMD) domain with that from other integral membrane proteins abolished ADAM17 activation. This points to a novel mechanism of ADAM17 regulation via its TMD. We hypothesize that the ADAM17 TMD integrates and interprets signals that drive ADAM activation and is the critical regulatory entity mediating the regulation of EGFR-ligand shedding by ADAM17.
Aim 1 is focused on defining the role of the TMD in activating ADAM17 through structure/function studies. The main goal of aim 2 is to define the major signaling effectors that activate ADAM17 via its TMD by combining inhibition experiments using pharmacological compounds and siRNA technology with activation of signaling pathways by forced expression of relevant signaling molecules. The experiments in aim 3 will rigorously test the role of the ADAM17 cytoplasmic domain in EGFR signaling in vivo in a new knock-in mouse model lacking the ADAM17 cytoplasmic domain. Together, these aims will resolve the most pressing current questions regarding the regulation of ADAM17, a major cellular sheddase that is a critical molecule in EGFR signaling and a target for treatment of cancer.
All ligands of the EGFR, a tyrosine kinase receptor with important roles in development and diseases such as cancer, must be proteolytically released to trigger EGFR- signaling. This proposal is focused on the principal metalloproteinase responsible for EGFR-ligand activation, ADAM17 (a disintegrin and metalloproteinase 17), and on understanding its regulation and function in the context of EGFR-signaling using cel- based assays and genetically modified mice.
|Qing, Xiaoping; D Rogers, Lindsay; Mortha, Arthur et al. (2016) iRhom2 regulates CSF1R cell surface expression and non-steady state myelopoiesis in mice. Eur J Immunol 46:2737-2748|
|Alabi, Rolake O; Glomski, Krzysztof; Haxaire, Coline et al. (2016) ADAM10-Dependent Signaling Through Notch1 and Notch4 Controls Development of Organ-Specific Vascular Beds. Circ Res 119:519-31|
|Noss, Erika H; Watts, Gerald F M; Zocco, Davide et al. (2015) Evidence for cadherin-11 cleavage in the synovium and partial characterization of its mechanism. Arthritis Res Ther 17:126|
|Li, Xue; Maretzky, Thorsten; Weskamp, Gisela et al. (2015) iRhoms 1 and 2 are essential upstream regulators of ADAM17-dependent EGFR signaling. Proc Natl Acad Sci U S A 112:6080-5|
|Maretzky, Thorsten; Evers, Astrid; Le Gall, Sylvain et al. (2015) The cytoplasmic domain of a disintegrin and metalloproteinase 10 (ADAM10) regulates its constitutive activity but is dispensable for stimulated ADAM10-dependent shedding. J Biol Chem 290:7416-25|
|Wong, Eitan; Maretzky, Thorsten; Peleg, Yoav et al. (2015) The Functional Maturation of A Disintegrin and Metalloproteinase (ADAM) 9, 10, and 17 Requires Processing at a Newly Identified Proprotein Convertase (PC) Cleavage Site. J Biol Chem 290:12135-46|
|Maney, Sathish K; McIlwain, David R; Polz, Robin et al. (2015) Deletions in the cytoplasmic domain of iRhom1 and iRhom2 promote shedding of the TNF receptor by the protease ADAM17. Sci Signal 8:ra109|
|Zhao, Ren; Wang, Aimin; Hall, Katherine C et al. (2014) Lack of ADAM10 in endothelial cells affects osteoclasts at the chondro-osseus junction. J Orthop Res 32:224-30|
|Hall, Katherine C; Hill, Daniel; Otero, Miguel et al. (2013) ADAM17 controls endochondral ossification by regulating terminal differentiation of chondrocytes. Mol Cell Biol 33:3077-90|
|Maretzky, Thorsten; McIlwain, David R; Issuree, Priya Darshinee A et al. (2013) iRhom2 controls the substrate selectivity of stimulated ADAM17-dependent ectodomain shedding. Proc Natl Acad Sci U S A 110:11433-8|
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