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.

Public Health Relevance

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.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM064750-11
Application #
8321956
Study Section
Molecular and Integrative Signal Transduction Study Section (MIST)
Program Officer
Flicker, Paula F
Project Start
2002-02-01
Project End
2015-05-31
Budget Start
2012-06-01
Budget End
2013-05-31
Support Year
11
Fiscal Year
2012
Total Cost
$351,000
Indirect Cost
$151,000
Name
Hospital for Special Surgery
Department
Type
DUNS #
622146454
City
New York
State
NY
Country
United States
Zip Code
10021
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
Groot, Arjan J; Cobzaru, Cristina; Weber, Silvio et al. (2013) Epidermal ADAM17 is dispensable for notch activation. J Invest Dermatol 133:2286-8
Hewing, Nina Jasmin; Weskamp, Gisela; Vermaat, Joost et al. (2013) Intravitreal injection of TIMP3 or the EGFR inhibitor erlotinib offers protection from oxygen-induced retinopathy in mice. Invest Ophthalmol Vis Sci 54:864-70
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
Hall, Katherine C; Blobel, Carl P (2012) Interleukin-1 stimulates ADAM17 through a mechanism independent of its cytoplasmic domain or phosphorylation at threonine 735. PLoS One 7:e31600
McIlwain, David R; Lang, Philipp A; Maretzky, Thorsten et al. (2012) iRhom2 regulation of TACE controls TNF-mediated protection against Listeria and responses to LPS. Science 335:229-32
La Marca, Rosa; Cerri, Federica; Horiuchi, Keisuke et al. (2011) TACE (ADAM17) inhibits Schwann cell myelination. Nat Neurosci 14:857-65
Thorp, Edward; Vaisar, Tomas; Subramanian, Manikandan et al. (2011) Shedding of the Mer tyrosine kinase receptor is mediated by ADAM17 protein through a pathway involving reactive oxygen species, protein kinase Cýý, and p38 mitogen-activated protein kinase (MAPK). J Biol Chem 286:33335-44
Maretzky, Thorsten; Evers, Astrid; Zhou, Wenhui et al. (2011) Migration of growth factor-stimulated epithelial and endothelial cells depends on EGFR transactivation by ADAM17. Nat Commun 2:229

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