The interaction of neuropilin-1 with vascular endothelial growth factor and its receptor flt-1.
Neuropilin-1 (NP-1) was first identified as a semaphorin receptor involved in neuron guidance. Subsequent studies demonstrated that NP-1 also binds an isoform of vascular endothelial growth factor (VEGF) as well as several VEGF homologs, suggesting that NP-1 may also function in angiogenesis. Here we report in vitro binding experiments that ... shed light on the interaction between VEGF165 and NP-1, as well as a previously unknown interaction between NP-1 and one of the VEGF receptor tyrosine kinases, VEGFR1 or Flt-1. BIAcore analysis demonstrated that, with the extracellular domain (ECD) of NP-1 immobilized at low density, VEGF165 bound with low affinity (K(d) = 2 microm) and fast kinetics. The interaction was dependent on the heparin-binding domain of VEGF165 and increased the affinity of VEGF165 for its signaling receptor VEGFR2 or kinase insert domain-containing receptor. The affinity of VEGF165 for the NP-1 ECD was greatly enhanced either by increasing the density of immobilized NP-1 (K(d) = 113 nm) or by the addition of heparin (K(d) = 25 nm). We attribute these affinity enhancements to avidity effects mediated by the bivalent VEGF165 homodimer or multivalent heparin. We also show that the NP-1 ECD binds with high affinity (K(d) = 1.8 nm) to domains 3 and 4 of Flt-1 and that this interaction inhibits the binding of NP-1 to VEGF165. Based on these results, we propose that NP-1 acts as a coreceptor for various ligands and that these functions are dependent on the density of NP-1 on the cell membrane. Furthermore, Flt-1 may function as a negative regulator of angiogenesis by competing for NP-1.
Mesh Terms:
Animals, CHO Cells, Cell Line, Cricetinae, Endothelial Growth Factors, Heparin, Humans, Lymphokines, Mice, Neovascularization, Physiologic, Nerve Tissue Proteins, Neuropilin-1, Protein Binding, Proto-Oncogene Proteins, Receptor Protein-Tyrosine Kinases, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factor Receptor-1, Vascular Endothelial Growth Factors
Animals, CHO Cells, Cell Line, Cricetinae, Endothelial Growth Factors, Heparin, Humans, Lymphokines, Mice, Neovascularization, Physiologic, Nerve Tissue Proteins, Neuropilin-1, Protein Binding, Proto-Oncogene Proteins, Receptor Protein-Tyrosine Kinases, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factor Receptor-1, Vascular Endothelial Growth Factors
J. Biol. Chem.
Date: Sep. 01, 2000
PubMed ID: 10842181
View in: Pubmed Google Scholar
Download Curated Data For This Publication
216280
Switch View:
- Interactions 3