title: Quantitative analysis of TIP47-receptor cytoplasmic domain interactions: implications for endosome-to-trans Golgi network trafficking.
abstract: TIP47 (tail-interacting protein of 47 kDa) binds to the cytoplasmic domains of the cation-independent and cation-dependent mannose 6-phosphate receptors and is required for their transport from late endosomes to the trans Golgi network in vitro and in vivo. We report here a quantitative analysis of the interaction of recombinant TIP47 with mannose 6-phosphate receptor cytoplasmic domains. Recombinant TIP47 binds more tightly to the cation-independent mannose 6-phosphate receptor (K(D) = 1 microm) than to the cation-dependent mannose 6-phosphate receptor (K(D) = 3 microm). In addition, TIP47 fails to interact with the cytoplasmic domains of the hormone-processing enzymes, furin, phosphorylated furin, and metallocarboxypeptidase D, as well as the cytoplasmic domain of TGN38, proteins that are also transported from endosomes to the trans Golgi network. Although these proteins failed to bind TIP47, furin and TGN38 were readily recognized by the clathrin adaptor, AP-2. These data suggest that TIP47 recognizes a very select set of cargo molecules. Moreover, our data suggest unexpectedly that furin, TGN38, and carboxypeptidase D may use a distinct vesicular carrier and perhaps a distinct route for transport between endosomes and the trans Golgi network.
authors.affiliation: Department of Biochemistry, Stanford University School of Medicine, CA 94305-5307, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Krise
authors.forename: P M
authors.initials: PM
authors.lastname: Sincock
authors.forename: J G
authors.initials: JG
authors.lastname: Orsel
authors.forename: S R
authors.initials: SR
authors.lastname: Pfeffer
mesh_terms: D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism; D002268:Carboxypeptidases / Q000378:metabolism; D002412:Cations; D002417:Cattle; D003593:Cytoplasm / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D011992:Endosomes / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005456:Fluorescent Dyes / Q000494:pharmacology; D045683:Furin; D005982:Glutathione Transferase / Q000378:metabolism; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism*; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D000070796:Perilipin-3; D010766:Phosphorylation; D011257:Pregnancy Proteins; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017527:Receptor, IGF Type 2 / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013381:Subtilisins / Q000378:metabolism; D033921:Vesicular Transport Proteins; D014966:Xanthenes / Q000494:pharmacology
chemical_list: D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D002412:Cations; D004268:DNA-Binding Proteins; D005456:Fluorescent Dyes; D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C038196:PLIN3 protein, human; D000070796:Perilipin-3; D011257:Pregnancy Proteins; D017527:Receptor, IGF Type 2; D011994:Recombinant Proteins; D033921:Vesicular Transport Proteins; D014966:Xanthenes; C034657:Texas red; D005982:Glutathione Transferase; D002268:Carboxypeptidases; C078874:carboxypeptidase D; D013381:Subtilisins; D045683:Furin