title: High-affinity binding of epidermal growth factor (EGF) to EGF receptor is disrupted by overexpression of mutant dynamin (K44A).
abstract: Activation of the epidermal growth factor receptor (EGFR) kinase was analyzed in cells conditionally defective for clathrin-dependent endocytosis by overexpression of mutant dynamin (K44A). EGF-induced autophosphorylation of the EGFR on ice was strongly reduced in cells overexpressing mutant dynamin, and consistently, binding analyses showed that high-affinity EGFRs were lost. In the absence of mutant dynamin the cells displayed both high- and low-affinity EGFR. At 4 degreesC EGF-EGFR localized mainly outside coated pits regardless of expression of mutant dynamin. However, also low-affinity EGFR efficiently moved to coated pits upon incubating cells at 37 degreesC. Thus, expression of mutant dynamin disrupts high-affinity binding of EGF, but not ligand-induced recruitment of EGFR to clathrin-coated pits.
authors.affiliation: Institute of Pathology, University of Oslo, The National Hospital, N-0027 Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Ringerike
authors.forename: E
authors.initials: E
authors.lastname: Stang
authors.forename: L E
authors.initials: LE
authors.lastname: Johannessen
authors.forename: D
authors.initials: D
authors.lastname: Sandnes
authors.forename: F O
authors.initials: FO
authors.lastname: Levy
authors.forename: I H
authors.initials: IH
authors.lastname: Madshus
mesh_terms: D034281:Dynamins; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D051966:Phospholipase C gamma; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D020558:GTP Phosphohydrolases; D034281:Dynamins