Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12Gallus gallusHomo sapiensMacaca mulattaMus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevis home help / support contribute downloads mirrors about us J. Biol. Chem. Aug (1994); 269(33):21346-52 Clathrin assembly protein AP-3 is phosphorylated and glycosylated on the 50-kDa structural domain. Murphy JE, Hanover JA, Froehlich M, DuBois G, Keen JH Laboratory of Biochemistry and Metabolism, NIDDKD, National Institutes of Health, Bethesda, Maryland 20892. Abstract: AP-3 (AP180) in rat sympathetic neurons maintained in culture was analyzed by pulse-chase labeling with [35S]methionine to look for post-translational modifications. At early times, two lower molecular weight precursors of the mature species were detected. By 10 min, all of the AP-3 was found in the mature form which is stable for at least 9 h. We show here that at least one of these processing events is due to the addition of O-linked N-acetylglucosamine (GlcNAc) which is present on the mature form of the protein. Wheat germ agglutinin, a GlcNAc-specific probe, bound to AP-3 and the binding was blocked by excess GlcNAc but not by excess mannose. Purified AP-3, and AP-3 in coated vesicles derived from bovine brain, served as substrates for beta-D-galactosyltransferase which is specific for terminal GlcNAc residues. Analysis of the disaccharide released by beta-elimination indicated that single GlcNAc residues are attached to AP-3 through an O-glycosidic linkage to threonine or serine residues. In vivo 32P-labeled AP-3, the result of serine phosphorylation (Keen, J. H., and Black, M.M. (1986) J. Cell Biol. 102, 1325-1333), bound to wheat germ agglutinin-Sepharose indicating that phosphorylation and glycosylation can occur simultaneously on the same molecule. Both modifications have been mapped to the central 50-kDa structural domain that is responsible for the anomalous migration of AP-3. Consistent with localization to the nonclathrin binding domain, the O-GlcNAc modification does not play a discernible role in the interaction of AP-3 with clathrin. [PUBMED: 8063760] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.