Characterization of the ectodomain shedding of the beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1).
Generation of the amyloid peptide through proteolytic processing of the amyloid precursor protein by beta- and gamma-secretases is central to the etiology of Alzheimer's disease. beta-secretase, known more widely as the beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), has been identified as a transmembrane aspartic proteinase, and its ectodomain has been reported to be cleaved and secreted from cells in a soluble form. The extracellular domains of many diverse proteins are known to be cleaved and secreted from cells by a process known as ectodomain shedding. Here we confirm that the ectodomain of BACE1 is secreted from cells and that this processing is up-regulated by agents that activate protein kinase C. A metalloproteinase is involved in the cleavage of BACE1 as hydroxamic acid-based metalloproteinase inhibitors abolish the release of shed BACE1. Using potent and selective inhibitors, we demonstrate that ADAM10 is a strong candidate for the BACE1 sheddase. In addition, we show that the BACE1 sheddase is distinct from alpha-secretase and, importantly, that inhibition of BACE1 shedding does not influence amyloid precursor protein processing at the beta-site.
Hussain
Ishrut
I
Neurology and Gastrointestinal Centre of Excellence for Drug Discovery, GlaxoSmithKline Research & Development Limited, New Frontiers Science Park, Third Avenue, Harlow, Essex, CM19 5AW, United Kingdom. Ishrut_2_Hussain@gsk.com
Hawkins
Julie
J
Shikotra
Aarti
A
Riddell
David R
DR
Faller
Andrew
A
Dingwall
Colin
C
D053829:Amyloid Precursor Protein Secretases; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry*; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry; D004789:Enzyme Activation; D006801:Humans; D006877:Hydroxamic Acids / Q000737:chemistry; D020128:Inhibitory Concentration 50; D008956:Models, Chemical; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015854:Up-Regulation
D006877:Hydroxamic Acids; D011493:Protein Kinase C; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human