title: A disintegrin and metalloproteinase (ADAM)-mediated ectodomain shedding of ADAM10.
abstract: A disintegrin and metalloproteinase (ADAM) 10 is a type I transmembrane glycoprotein responsible for the ectodomain shedding of a range of proteins including the amyloid precursor protein implicated in Alzheimer's disease. In this study we demonstrate that ADAM10 itself is subject to shedding by one or more ADAMs. Expression of epitope-tagged wild-type ADAM10 in SH-SY5Y cells enabled the detection of a soluble ectodomain in conditioned medium. Shedding of the ADAM10 ectodomain was inhibited by a known ADAM inhibitor with a reciprocal accumulation of the full-length mature protein in both cell lysates and extracellular membrane vesicles. Shedding was also stimulated by phorbol ester treatment of cells. A glycosylphosphatidylinositol-anchored form of ADAM10 lacking the cytosolic, transmembrane and alpha-helical juxtamembrane regions of the wild-type protein was shed in a similar manner. Furthermore, a truncated soluble ADAM10 construct, although correctly post-translationally processed and catalytically active against a synthetic peptide substrate, was incapable of shedding cell-associated amyloid precursor protein. Finally, we show that ADAM9 is, at least in part, responsible for the ectodomain shedding of ADAM10. In conclusion, this is a new mechanism by which levels of ADAM10 are regulated and may have implications in a range of human diseases including Alzheimer's disease.
authors.affiliation: Division of Biomedical and Life Sciences, School of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK. e.parkin@lancaster.ac.uk
authors.forename: Edward
authors.initials: E
authors.lastname: Parkin
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harris
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000502:physiology*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000502:physiology*; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D001120:Arginine / Q000235:genetics; D002460:Cell Line; D019483:Disintegrins / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D045726:Metalloproteases / Q000502:physiology*; D009154:Mutation; D009447:Neuroblastoma; D010455:Peptides / Q000378:metabolism; D054801:Phosphoinositide Phospholipase C / Q000494:pharmacology; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection / Q000379:methods
chemical_list: D016564:Amyloid beta-Protein Precursor; D019483:Disintegrins; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D010455:Peptides; D034741:RNA, Small Interfering; D001120:Arginine; D054801:Phosphoinositide Phospholipase C; D053829:Amyloid Precursor Protein Secretases; D045726:Metalloproteases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; D013755:Tetradecanoylphorbol Acetate