title: Furin is an endogenous regulator of alpha-secretase associated APP processing.
abstract: Constitutive and PKC-regulated alpha-secretase pathways have been reported to produce the secreted form of alpha-secretase-derived APP (sAPPalpha). Here, we examined putative role of furin in the regulation of alpha-secretase activity in vitro and in vivo. Overexpression of the prodomain of furin and infection with a furin-specific inhibitor significantly reduced the levels of sAPPalpha regardless of PKC activity, whereas total APP levels remained unchanged. Furin mRNA levels in the brains of AD patients and Tg2576 mice were significantly lower than those in controls, whereas ADAM10 and TACE mRNA levels were much alike between Tg2576 and littermate mice. Moreover, the injection of furin-adenovirus into Tg2576 mouse brains markedly increased alpha-secretase activity and reduced beta-amyloid protein (Abeta) production in infected brain regions. Our results suggest that furin enhances alpha-secretase activity via the cleavage of ADAM10 and TACE, and that attenuated furin activity is connected to the production of Abeta.
authors.affiliation: Department of Physiology, Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, Republic of Korea.
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Hwang
authors.forename: Su-Kyoung
authors.initials: SK
authors.lastname: Kim
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Sohn
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Lee
authors.forename: Youngho
authors.initials: Y
authors.lastname: Kim
authors.forename: Yong Shik
authors.initials: YS
authors.lastname: Kim
authors.forename: Inhee
authors.initials: I
authors.lastname: Mook-Jung
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism; D000072198:ADAM17 Protein; D000544:Alzheimer Disease / Q000378:metabolism; D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D002522:Chlorocebus aethiops; D010450:Endopeptidases / Q000378:metabolism*; D045683:Furin / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic
chemical_list: D016564:Amyloid beta-Protein Precursor; D049452:Green Fluorescent Proteins; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; C468731:FURIN protein, human; D045683:Furin; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human; C509282:Bace1 protein, mouse; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606463:Adam17 protein, mouse