Constitutive and regulated alpha-secretase cleavage of Alzheimer's amyloid precursor protein by a disintegrin metalloprotease.
Amyloid beta peptide (Abeta), the principal proteinaceous component of amyloid plaques in brains of Alzheimer's disease patients, is derived by proteolytic cleavage of the amyloid precursor protein (APP). Proteolytic cleavage of APP by a putative alpha-secretase within the Abeta sequence precludes the formation of the amyloidogenic peptides and leads to the release of soluble APPsalpha into the medium. By overexpression of a disintegrin and metalloprotease (ADAM), classified as ADAM 10, in HEK 293 cells, basal and protein kinase C-stimulated alpha-secretase activity was increased severalfold. The proteolytically activated form of ADAM 10 was localized by cell surface biotinylation in the plasma membrane, but the majority of the proenzyme was found in the Golgi. These results support the view that APP is cleaved both at the cell surface and along the secretory pathway. Endogenous alpha-secretase activity was inhibited by a dominant negative form of ADAM 10 with a point mutation in the zinc binding site. Studies with purified ADAM 10 and Abeta fragments confirm the correct alpha-secretase cleavage site and demonstrate a dependence on the substrate's conformation. Our results provide evidence that ADAM 10 has alpha-secretase activity and many properties expected for the proteolytic processing of APP. Increases of its expression and activity might be beneficial for the treatment of Alzheimer's disease.
Lammich
S
S
Institut für Biochemie, Johannes Gutenberg-Universität, Mainz, Becherweg 30, D-55128 Mainz, Germany.
Kojro
E
E
Postina
R
R
Gilbert
S
S
Pfeiffer
R
R
Jasionowski
M
M
Haass
C
C
Fahrenholz
F
F
D051722:ADAM Proteins; D000072197:ADAM10 Protein; D000595:Amino Acid Sequence; D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D001665:Binding Sites; D002417:Cattle; D002460:Cell Line; D003001:Cloning, Molecular; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics*; D008666:Metalloendopeptidases / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D017354:Point Mutation; D011493:Protein Kinase C / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014162:Transfection; D015032:Zinc / Q000378:metabolism
C000600731:APPsalpha protein, mouse; D016564:Amyloid beta-Protein Precursor; D008565:Membrane Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D011493:Protein Kinase C; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human; D051722:ADAM Proteins; D008666:Metalloendopeptidases; C103778:ADAM 10 protein, Bos taurus; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human; D015032:Zinc