Vascular endothelial growth factor receptor 2 (VEGFR2) and neuropilin-1 (NRP1) complex (VEGFR2/NRP1)

The Vascular endothelial growth factor receptor (VEGFR) and neuropilin-1 (NRP1) co-receptor complex is a fundamental regulator of physiological and pathological angiogenesis (Soker et al., 1998, PMID: 9529252). VEGFRs, particularly VEGFR2 (KDR), are receptor tyrosine kinases that mediate the primary mitogenic and permeability-inducing effects of VEGF-A. NRP1 serves as a critical co-receptor that lacks intrinsic catalytic activity but significantly enhances the binding affinity of the VEGF-A165 isoform to VEGFR2, thereby amplifying downstream signaling pathways such as MAPK/ERK and PI3K/Akt (Ballmer-Hofer et al., 2011, PMID: 21562181). This synergistic interaction is essential for endothelial cell survival, migration, and the formation of functional vascular networks. In many solid tumors, the co-expression of VEGFR2 and NRP1 is upregulated, driving aggressive tumor vascularization and contributing to a poor prognosis (Grandclement & Borg, 2011, PMID: 24212984). Therapeutic targeting of this complex involves monoclonal antibodies that neutralize the VEGF ligand, block the receptor's extracellular domain, or disrupt the specific binding interface between NRP1 and VEGFR2. While effective in treating various cancers and neovascular eye diseases, inhibition of this pathway is associated with systemic toxicities, including hypertension and proteinuria, due to the role of VEGF signaling in maintaining normal vascular homeostasis (Eremina et al., 2008, PMID: 18337650).

Other names

VEGF-R/NRP1 complexVEGFR2-NRP1 signaling complexNeuropilin-1/VEGFR2VEGF receptor-neuropilin complexVEGFR-NRP1

The mechanism of action for drugs targeting this complex involves the sequestration of VEGF ligands (e.g., Bevacizumab, Aflibercept), competitive inhibition of the VEGFR extracellular binding domains (e.g., Ramucirumab), or the disruption of the specific interaction between the NRP1 b1b2 domain and the VEGFR2 extracellular domain (e.g., MNRP1685A). These actions prevent the formation of the high-affinity ternary signaling complex, thereby inhibiting the activation of downstream tyrosine kinase pathways such as PLC-gamma, MAPK/ERK, and PI3K/Akt, which are essential for endothelial cell proliferation and migration (Ferrara et al., 2004, PMID: 15170202; Pan et al., 2007, PMID: 17350570).