Amyloid beta/A4 precursor protein (APP) processing in lysosomes.
Alzheimer's disease (AD) is characterized by the formation of senile plaques, the main component of which is amyloid beta protein. The processing of the amyloid beta/A4 protein has been implicated in the pathogenesis of AD. We have reported cathepsin B as a candidate APP secretase. By using APP-transfected COS-1 cells, we determined that the putative APP secretase, lysosomal cathepsin B, is involved in the constitutive processing of the precursor molecule. Digestion experiments demonstrated that cathepsin B cleaves the APP molecule into two fragments with molecular masses 115 kDa and 9 kDa, representing presumptive proteolytic fragments of constitutive processing.
Tagawa
K
K
National Institute of Neuroscience, NCNP, Tokyo, Japan.
Maruyama
K
K
Ishiura
S
S
D000544:Alzheimer Disease / Q000378:metabolism*; D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D002401:Cathepsin B / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
D016564:Amyloid beta-Protein Precursor; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D002401:Cathepsin B; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human