Antagonistic effect of EGF on FAK phosphorylation/dephosphorylation in a cell

Cell Biochem Funct. 2008 Sep-Oct;26(5):539-47. doi: 10.1002/cbf.1457.

Abstract

Focal adhesion kinase (FAK) plays a key role in the crosstalk of growth factor- and cell adhesion-mediated signaling pathway. In this study, we found that the quantitative change of phosphorylated FAK was bell-shaped time-dependently by EGF stimulation in immortalized human keratinocyte (HaCaT). EGF enhanced FAK phosphorylation and cell spreading in adhering HaCaT cells with low-phosphorylated FAK. On the other hand, spread HaCaT cells having high-phosphorylated FAK changed to round shapes with FAK dephosphorylation 15 min after EGF stimulation. Pharmacological agents, U0126 and PD98059 (mitogen-activated protein kinases (MAPK) kinases (MEK) inhibitors), and AG1478 (an EGF receptor kinase inhibitor) blocked the cell rounding and FAK dephosphorylation. In addition, the EGFR-MAPK signaling pathway had an influence on cell migration by regulating FAK dephosphorylation of keratinocytes in response of EGF, since the MEK inhibitors and AG1478 suppressed EGF-induced cell migration. However, FAK phosphorylation and HaCaT cell spreading were inhibited only by the antagonist of EGF-EGFR binding but not by the MEK inhibitors and AG1478. Taken together, we suggest that EGF is antagonistically involved in both FAK phosphorylation and dephosphorylation with different mechanisms in a cell.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion / physiology
  • Cell Line
  • Cell Movement / physiology
  • Epidermal Growth Factor / physiology*
  • Focal Adhesion Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / enzymology*
  • Keratinocytes / metabolism
  • Phosphorylation

Substances

  • Epidermal Growth Factor
  • Focal Adhesion Protein-Tyrosine Kinases