Journal Article

Regulated ADAM17-dependent EGF family ligand release by substrate-selecting signaling pathways

Armbruster, Nicole, Miller, Miles A., Root, David E., Cermeno, Efrain, Herrlich, Andreas, Hartmann, Monika, Dang, Michelle, Lauffenburger, Douglas A., Lodish, Harvey F., Bell, George W.

2013

Overview

Ectodomain cleavage of cell-surface proteins by A disintegrin and metalloproteinases (ADAMs) is highly regulated, and its dysregulation has been linked to many diseases. ADAM10 and ADAM17 cleave most disease-relevant substrates. Broad-spectrum metalloprotease inhibitors have failed clinically, and targeting the cleavage of a specific substrate has remained impossible. It is therefore necessary to identify signaling intermediates that determine substrate specificity of cleavage. We show here that phorbol ester or angiotensin II-induced proteolytic release of EGF family members may not require a significant increase in ADAM17 protease activity. Rather, inducers activate a signaling pathway using PKC-α and the PKC-regulated protein phosphatase 1 inhibitor 14D that is required for ADAM17 cleavage of TGF-α, heparin-binding EGF, and amphiregulin. A second pathway involving PKC-δ is required for neuregulin (NRG) cleavage, and, indeed, PKC-δ phosphorylation of serine 286 in the NRG cytosolic domain is essential for induced NRG cleavage. Thus, signaling-mediated substrate selection is clearly distinct from regulation of enzyme activity, an important mechanism that offers itself for application in disease.

• Publisher: National Academy of Sciences
• Subject: ADAM Proteins - genetics / ADAM Proteins - metabolism / ADAM17 Protein / Amphiregulin / Angiotensin II - pharmacology / Biological Sciences / Blotting, Western / Cell Biology / Cell Line, Tumor / Cells / Down regulation / EGF Family of Proteins / Enzymatic activity / Enzyme Activation - drug effects / enzyme activity / Enzymes / Epidermal Growth Factor - metabolism / Flow Cytometry / Fluorescence / Gene expression regulation / Glycoproteins - genetics / Glycoproteins - metabolism / HEK293 Cells / Humans / Intercellular Signaling Peptides and Proteins - genetics / Intercellular Signaling Peptides and Proteins - metabolism / Isoenzymes - metabolism / Jurkat Cells / Ligands / metalloproteinases / Phosphorylation / Physiological regulation / Proteases / protein kinase C / Protein Kinase C - metabolism / Proteins / Proteins - metabolism / proteolysis / Proteolysis - drug effects / Receptors / RNA Interference / serine / Serine - genetics / Serine - metabolism / Signal Transduction / Substrate Specificity / Substrates / T lymphocytes / Tetradecanoylphorbol Acetate - pharmacology / transforming growth factor alpha / Transforming Growth Factor alpha - genetics / Transforming Growth Factor alpha - metabolism