Journal
GLYCOCONJUGATE JOURNAL
Volume 21, Issue 1-2, Pages 25-29Publisher
SPRINGER
DOI: 10.1023/B:GLYC.0000043743.21735.ff
Keywords
alpha 2,6-sialyltransferase (ST6Gal I); secretion; beta-secretase (BACE1); proteases; glycosyltransferases; the Golgi apparatus; Alzheimer's disease; amyloid precursor protein
Categories
Ask authors/readers for more resources
Alzheimer's beta-secretase (BACE1) cleaves amyloid precursor protein to produce amyloid beta-peptide, which is a crucial initiation process of the pathogenesis of Alzheimer's disease. We previously found that BACE1 also cleaves a membrane-bound sialyltransferase (ST6Gal I). Here we report that, when the protein A-ST6Gal I fusion protein, or ST6Gal I-derived peptide, was used as an in vitro substrate for BACE1, it cleaved the substrates between Leu(37) and Gln(38). However, a soluble form of ST6Gal I secreted from COS cells started from Glu(41), which was three amino acids shorter than the in vitro product. The results suggested that the BACE1 product was truncated by an aminopeptidase(s) before secretion. The aminopeptidase activity was successfully detected in detergent extracts of Golgi-membrane fraction. Taken together, we concluded that BACE1 initially cleaved ST6Gal I between Leu(37) and Gln(38), and the NH2-terminal three amino acids of the yielded product was further trimmed by the aminopeptidase.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available