The endocytic pathway followed by the keratinocyte growth factor receptor

Francesca Belleudi, Mara Ceridono, Alessandro Capone, Annalucia Serafino, Cinzia Marchese, Mauro Picardo, Luigi Frati, Maria Torrisi

Research output: Contribution to journalArticle

Abstract

Keratinocyte growth factor (KGF/FGF7) acts specifically on epithelial cells and regulates their proliferation and differentiation. It binds to and activates a receptor tyrosine kinase, the KGF receptor (KGFR), which is a splicing variant of the fibroblast growth factor receptor 2. The endocytic pathway followed by KGF and its receptor was analyzed here using immunofluorescence and confocal microscopy. After 10 min of internalization at 37°C, both KGF and its receptor were localized in early endosomes, and after 30-60 min of endocytosis ligand and receptor were seen to reach perinuclear late endosomes and not the recycling endosomal compartment. Parallel western blot analysis revealed that KGFRs were tyrosine phosphorylated both at early and late steps of internalization, suggesting that KGF and KGFR remain associated in active complexes through the endocytic pathway. Pulse-chase experiments showed that the internalized KGFRs underwent degradation detectable at 1 h of endocytosis at 37°C, indicating that KGFRs are functionally downregulated.

Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalHistochemistry and Cell Biology
Volume118
Issue number1
Publication statusPublished - 2002

    Fingerprint

Keywords

  • Endocytosis
  • Keratinocyte growth factor
  • Keratinocyte growth factor receptor

ASJC Scopus subject areas

  • Cell Biology
  • Instrumentation

Cite this

Belleudi, F., Ceridono, M., Capone, A., Serafino, A., Marchese, C., Picardo, M., Frati, L., & Torrisi, M. (2002). The endocytic pathway followed by the keratinocyte growth factor receptor. Histochemistry and Cell Biology, 118(1), 1-10.