Urokinase-induced signaling in human vascular smooth muscle cells is mediated by PDGFR-beta

EMBO J. 2005 May 18;24(10):1787-97. doi: 10.1038/sj.emboj.7600669. Epub 2005 May 5.

Abstract

Urokinase (uPA)-induced signaling in human vascular smooth muscle cells (VSMC) elicits important cellular functional responses, such as cell migration and proliferation. However, how intracellular signaling is linked to glycolipid-anchored uPA receptor (uPAR) is unknown. We provide evidence that uPAR activation by uPA induces its association with platelet-derived growth factor receptor (PDGFR)-beta. The interaction results in PDGF-independent PDGFR-beta activation by phosphorylation of cytoplasmic tyrosine kinase domains and receptor dimerization. Association of the receptors as well as the tyrosine kinase activity of PDGFR-beta are decisive in mediating uPA-induced downstream signaling that regulates VSMC migration and proliferation. These findings provide a molecular basis for mechanisms VSMC use to induce uPAR- and PDGFR-directed signaling. The processes may be relevant to VSMC function and vascular remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • DNA-Binding Proteins / metabolism
  • Dimerization
  • Humans
  • Muscle, Smooth, Vascular / metabolism*
  • Phosphorylation
  • Receptor, Platelet-Derived Growth Factor beta / metabolism*
  • STAT1 Transcription Factor
  • Trans-Activators / metabolism
  • Urokinase-Type Plasminogen Activator / metabolism*
  • rhoA GTP-Binding Protein / metabolism

Substances

  • DNA-Binding Proteins
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • Trans-Activators
  • Receptor, Platelet-Derived Growth Factor beta
  • Urokinase-Type Plasminogen Activator
  • rhoA GTP-Binding Protein