title: Hrs interacts with sorting nexin 1 and regulates degradation of epidermal growth factor receptor.
abstract: Hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) is a mammalian homologue of yeast vacuolar protein sorting (Vps) protein Vps27p; however, the role of Hrs in lysosomal trafficking is unclear. Here, we report that Hrs interacts with sorting nexin 1 (SNX1), a recently identified mammalian homologue of yeast Vps5p that recognizes the lysosomal targeting code of epidermal growth factor receptor (EGFR) and participates in lysosomal trafficking of the receptor. Biochemical analyses demonstrate that Hrs and SNX1 are ubiquitous proteins that exist in both cytosolic and membrane-associated pools, and that the association of Hrs and SNX occurs on cellular membranes but not in the cytosol. Furthermore, endogenous SNX1 and Hrs form a approximately 550-kDa complex that excludes EGFR. Immunofluorescence and subcellular fractionation studies show that Hrs and SNX1 colocalize on early endosomes. By using deletion analysis, we have mapped the binding domains of Hrs and SNX1 that mediate their association. Overexpression of Hrs or its SNX1-binding domain inhibits ligand-induced degradation of EGFR, but does not affect either constitutive or ligand-induced receptor-mediated endocytosis. These results suggest that Hrs may regulate lysosomal trafficking through its interaction with SNX1.
authors: Department of Pharmacology and of Cell and Molecular Physiology, Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina, Chapel Hill 27599, USA.
authors: L S
authors: LS
authors: Chin
authors: M C
authors: MC
authors: Raynor
authors: X
authors: X
authors: Wei
authors: H Q
authors: HQ
authors: Chen
authors: L
authors: L
authors: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004705:Endocytosis; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D017353:Gene Deletion; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008247:Lysosomes / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013347:Subcellular Fractions; D014018:Tissue Distribution; D014162:Transfection; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D056827:Endosomal Sorting Complexes Required for Transport; D008024:Ligands; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; C096164:hepatocyte growth factor-regulated tyrosine kinase substrate; D005982:Glutathione Transferase; D066246:ErbB Receptors