Teacher:In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
Teacher: Now, understand the problem? Solve this instance: PROGRESSIVE cerebral deposition of the amyloid -peptide is an early and invariant feature of Alzheimer's disease. The -peptide is released by proteolytic cleavages from the -amyloid precursor protein (APP)1, a membrane-spanning glycoprotein expressed in most mammalian cells. Normal secretion of APP involves a cleavage in the -peptide region2-3, releasing the soluble extramembranous portion4,5 and retaining a 10K C-terminal fragment in the membrane6. Because this secretory pathway precludes -amyloid formation, we searched for an alternative proteolytic processing pathway that can generate -peptide-bearing fragments from full-length APP. Incubation of living human endothelial cells with a APP antibody revealed reinternalization of mature APP from the cell surface and its targeting to endosomes/lysosomes. After cell-surface biotinylation, full-length biotinylated APP was recovered inside the cells. Purification of lysosomes directly demonstrated the presence of mature APP and an extensive array of -peptide-containing proteolytic products. Our results define a second processing pathway for APP and suggest that it may be responsible for generating amyloid-bearing fragments in Alzheimer's disease.
Student:
Targeting of cell-surface -amyloid precursor protein to lysosomes: alternative processing into amyloid-bearing fragments