PEST motif serine and tyrosine phosphorylation controls vascular endothelial growth factor receptor 2 stability and downregulation

Mol Cell Biol. 2011 May;31(10):2010-25. doi: 10.1128/MCB.01006-10. Epub 2011 Mar 14.

Abstract

The internalization and degradation of vascular endothelial growth factor receptor 2 (VEGFR-2), a potent angiogenic receptor tyrosine kinase, is a central mechanism for the regulation of the coordinated action of VEGF in angiogenesis. Here, we show that VEGFR-2 is ubiquitinated in response to VEGF, and Lys 48-linked polyubiquitination controls its degradation via the 26S proteosome. The degradation and ubiquitination of VEGFR-2 is controlled by its PEST domain, and the phosphorylation of Ser1188/Ser1191 is required for the ubiquitination of VEGFR-2. F-box-containing β-Trcp1 ubiquitin E3 ligase is recruited to S1188/S1191 VEGFR-2 and mediates the ubiquitination and degradation of VEGFR-2. The PEST domain also controls the activation of p38 mitogen-activated protein kinase (MAPK) through phospho-Y1173. The activation of p38 stabilizes VEGFR-2, and its inactivation accelerates VEGFR-2 downregulation. The VEGFR-2-mediated activation of p38 is established through the protein kinase A (PKA)/MKK6 pathway. PKA is recruited to VEGFR-2 through AKAP1/AKAP149, and its phosphorylation requires Y1173 of VEGFR-2. The study has identified a unique mechanism in which VEGFR-2 stability and degradation is modulated. The PEST domain acts as a dual modulator of VEGFR-2; the phosphorylation of S1188/S1191 controls ubiquitination and degradation via β-Trcp1, where the phosphorylation of Y1173 through PKA/p38 MAPK controls the stability of VEGFR-2.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / metabolism
  • Animals
  • Blotting, Western
  • Cell Line
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Endothelial Cells / metabolism
  • Humans
  • Immunoprecipitation
  • MAP Kinase Kinase 6 / metabolism
  • Mutagenesis, Site-Directed
  • Neovascularization, Physiologic*
  • Phosphorylation
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Stability
  • RNA, Small Interfering
  • Serine / metabolism
  • Signal Transduction
  • Swine
  • Tyrosine / metabolism
  • Ubiquitination
  • Vascular Endothelial Growth Factor A / metabolism*
  • Vascular Endothelial Growth Factor Receptor-2 / chemistry*
  • Vascular Endothelial Growth Factor Receptor-2 / genetics
  • Vascular Endothelial Growth Factor Receptor-2 / metabolism*
  • beta-Transducin Repeat-Containing Proteins / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • A Kinase Anchor Proteins
  • AKAP1 protein, human
  • BTRC protein, human
  • RNA, Small Interfering
  • Vascular Endothelial Growth Factor A
  • beta-Transducin Repeat-Containing Proteins
  • Tyrosine
  • Serine
  • Vascular Endothelial Growth Factor Receptor-2
  • Cyclic AMP-Dependent Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase 6
  • MAP2K6 protein, human
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease