title: Epidermal growth factor receptors destined for the nucleus are internalized via a clathrin-dependent pathway.
abstract: The epidermal growth factor (EGF) transduces its actions via the EGF receptor (EGFR), which can traffic from the plasma membrane to either the cytoplasm or the nucleus. However, the mechanism by which EGFR reaches the nucleus is unclear. To investigate these questions, liver cells were analyzed by immunoblot of cell fractions, confocal immunofluorescence and real time confocal imaging. Cell fractionation studies showed that EGFR was detectable in the nucleus after EGF stimulation with a peak in nuclear receptor after 10 min. Movement of EGFR to the nucleus was confirmed by confocal immunofluorescence and labeled EGF moved with the receptor to the nucleus. Small interference RNA (siRNA) was used to knockdown clathrin in order to assess the first endocytic steps of EGFR nuclear translocation in liver cells. A mutant dynamin (dynamin K44A) was also used to determine the pathways for this traffic. Movement of labeled EGF or EGFR to the nucleus depended upon dynamin and clathrin. This identifies the pathway that mediates the first steps for EGFR nuclear translocation in liver cells.
authors.affiliation: Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: De Angelis Campos
authors.forename: Michele Angela
authors.initials: MA
authors.lastname: Rodrigues
authors.forename: Carolina
authors.initials: C
authors.lastname: de Andrade
authors.forename: Alfredo Miranda
authors.initials: AM
authors.lastname: de Goes
authors.forename: Michael H
authors.initials: MH
authors.lastname: Nathanson
authors.forename: Dawidson A
authors.initials: DA
authors.lastname: Gomes
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000201:enzymology*; D002478:Cells, Cultured; D002966:Clathrin / Q000235:genetics / Q000378:metabolism*; D034281:Dynamins / Q000235:genetics / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D022781:Hepatocytes / Q000201:enzymology; D006801:Humans; D008099:Liver / Q000201:enzymology*; D009154:Mutation; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats
chemical_list: D002966:Clathrin; D034741:RNA, Small Interfering; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D034281:Dynamins