Angiogenesis, the production of new blood vessels from existing vasculature, is required for normal development, wound repair, and vascular homeostasis. Neuropilin is an essential mammalian cell surface receptor for one of the most potent pro-angiogenic molecules, vascular endothelial growth factor (VEGF), and functions in synchrony with VEGFR receptor tyrosine kinases. Neuropilin is of particular medical importance because it is critical to the pathology of VEGF dependent hyper-vascularization in tumor angiogenesis. We propose a series of parallel and complementary structural and functional studies to understand the physical interactions and receptor coupling at the heart of the VEGF signaling complex. Unlike many other kinase systems, VEGF binding to VEGFR in the absence of neuropilin is insufficient to induce angiogenesis. We seek to first understand the molecular mechanism(s) underlying neuropilin's unique role in VEGF dependant angiogenesis.
In Aim 1, we will determine the basis for competitive binding of ligands to neuropilin, and the role that this competition plays in regulating angiogenesis.
In Aim 2, we will explore the structural and conformational changes that neuropilin undergoes in its transition from inactive monomer to activated dimer. More globally, we seek to define the physical basis for the coordinated action of VEGF, neuropilin, and VEGFR.
Aim 3 is focused on utilizing multiple structural and biochemical tools coupled with endothelial cell signaling assays to determine the physical interactions and conformational changes necessary to couple extracellular ligand binding to receptor activation. Taken together, these studies will provide a molecular understanding of the physical mechanisms underlying the critical first step connecting VEGF ligand binding to receptor activation.

Public Health Relevance

Neuropilin is an essential receptor needed for the formation of new blood vessels. New blood vessels are critical during normal development and wound repair but also provide a tumor with critical nutrients for its growth. Understanding how neuropilin works in the formation of new blood vessels will help us understand how this pathway normally functions and how we can block its activity in tumors and related diseases.

National Institute of Health (NIH)
Research Project (R01)
Project #
Application #
Study Section
Macromolecular Structure and Function C Study Section (MSFC)
Program Officer
Dunsmore, Sarah
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Kentucky
Schools of Medicine
United States
Zip Code
Li, Xiaobo; Parker, Matthew W; Vander Kooi, Craig W (2014) Control of cellular motility by neuropilin-mediated physical interactions. Biomol Concepts 5:157-66
Parker, Matthew W; Vander Kooi, Craig W (2014) Microplate-based screening for small molecule inhibitors of neuropilin-2/vascular endothelial growth factor-C interactions. Anal Biochem 453:4-6
Guo, Hou-Fu; Li, Xiaobo; Parker, Matthew W et al. (2013) Mechanistic basis for the potent anti-angiogenic activity of semaphorin 3F. Biochemistry 52:7551-8
Parker, Matthew W; Linkugel, Andrew D; Vander Kooi, Craig W (2013) Effect of C-terminal sequence on competitive semaphorin binding to neuropilin-1. J Mol Biol 425:4405-14
Parker, Matthew W; Xu, Ping; Li, Xiaobo et al. (2012) Structural basis for selective vascular endothelial growth factor-A (VEGF-A) binding to neuropilin-1. J Biol Chem 287:11082-9
Fulkerson, Zachary; Wu, Tao; Sunkara, Manjula et al. (2011) Binding of autotaxin to integrins localizes lysophosphatidic acid production to platelets and mammalian cells. J Biol Chem 286:34654-63
Hausmann, Jens; Kamtekar, Satwik; Christodoulou, Evangelos et al. (2011) Structural basis of substrate discrimination and integrin binding by autotaxin. Nat Struct Mol Biol 18:198-204