Receptor involved in the development of the cardiovascular system, in angiogenesis, in the formation of certain neuronal circuits and in organogenesis outside the nervous system (By similarity). Mediates the chemorepulsant activity of semaphorins (PubMed:26503042). Recognizes a C-end rule (CendR) motif R/KXXR/K on its ligands which causes cellular internalization and vascular leakage (By similarity). Binds to semaphorin 3A (SEMA3A), the PLGF-2 isoform of PGF, the VEGF165 isoform of VEGFA and VEGFB (By similarity). Coexpression with KDR results in increased VEGF165 binding to KDR as well as increased chemotaxis. Regulates VEGF-induced angiogenesis (By similarity). Binding to VEGFA initiates a signaling pathway needed for motor neuron axon guidance and cell body migration, including for the caudal migration of facial motor neurons from rhombomere 4 to rhombomere 6 during embryonic development (PubMed:26503042). Regulates mitochondrial iron transport via interaction with ABCB8/MITOSUR (By similarity). Homodimer, and heterodimer with NRP2 (By similarity). Binds PLXNB1 (By similarity). Interacts with FER (PubMed:20133938). Interacts with VEGFA (PubMed:26503042). Interacts with ABCB8/MITOSUR in mitochondria (By similarity). Nervous system. The tandem CUB domains mediate binding to semaphorin, while the tandem F5/8 domains are responsible for heparin and VEGF binding. F5/8 domains mediate the recognition and binding to R/KXXR/K CendR motifs. Knockout embryos display higher susceptibility to oxidative stress in endothelium cells located in the intersomitic vessels. Belongs to the neuropilin family.