N-linked oligosaccharide of beta-amyloid precursor protein (beta APP) of C6 glioma cells: putative regulatory role in beta APP processing.
To determine the N-linked oligosaccharide structure of beta-amyloid precursor protein (beta APP), soluble derivative of beta APP (APPs) was purified from the conditioned medium of beta APP cDNA-transfected C6 glioma cells. Two types of APPs with different molecular weight (larger APPs, L-APPs; smaller APPs, S-APPs) were obtained. The antibody against the N-terminal half of amyloid beta-protein showed no immunoreactivity with S-APPs, suggesting extensive truncation at the carboxyl terminus. From lectin blot analysis, the main structure of the N-linked oligosaccharide shared by L- and S-APPs was deduced to be of bi- or triantennary complex type with a fucosylated trimannosyl core and a bisecting GlcNAc residue. Additionally L-APPs was deduced to have Gal beta 1-->4GlcNAc, Fuc alpha 1-->2Gal beta and Sia alpha 2-->6Gal beta structures on its outer chains. However, lectins which recognize Fuc alpha 1-->2Gal beta and Sia alpha 2-->6Gal beta structures showed no reactivity with S-APPs. The present results suggest that the processing of beta APP may be regulated via the heterogeneity in the fine structure of its sugar chains.
Saito
F
F
Department of Neurology, School of Medicine, Tokyo Medical and Dental University, Japan.
Tani
A
A
Miyatake
T
T
Yanagisawa
K
K
D016564:Amyloid beta-Protein Precursor / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002460:Cell Line; D018076:DNA, Complementary; D005910:Glioma; D006801:Humans; D037102:Lectins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009838:Oligodeoxyribonucleotides; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D014162:Transfection; D014407:Tumor Cells, Cultured
D016564:Amyloid beta-Protein Precursor; D018076:DNA, Complementary; D037102:Lectins; D009838:Oligodeoxyribonucleotides; D009844:Oligosaccharides; D011994:Recombinant Proteins