Synapsins contain O-linked N-acetylglucosamine.
The neuron-specific synaptic vesicle-associated phosphoproteins synapsin I and synapsin II were shown to contain terminal N-acetylglucosamine (GlcNAc) residues as determined by specific labeling with bovine galactosyltransferase and UDP-[3H]galactose. The beta-elimination of galactosyltransferase radiolabeled synapsin I and subsequent analysis of released saccharide on high-voltage paper electrophoresis confirmed the presence of monosaccharidic GlcNAc moieties in O-linkage to the protein. Partial cleavage of synapsin I by collagenase, 2-nitro-5-thiocyanobenzoic acid, and Staphylococcus aureus V8 protease suggests that at least three glycosylation sites exist along the molecule. Taken together these data present the first evidence that a neuron-specific protein contains O-glycosidically bound GlcNAc.
Lüthi
T
T
Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, New York 10021.
Haltiwanger
R S
RS
Greengard
P
P
Bähler
M
M
D000117:Acetylglucosamine / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D005690:Galactose / Q000378:metabolism; D006031:Glycosylation; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D016704:Synapsins
D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D016704:Synapsins; D000117:Acetylglucosamine; D005690:Galactose