01805nas a2200217   4500008004100000245007400041210006900115260001400184300001400198490000700212520115600219100002201375700002501397700002101422700002101443700001801464700001801482700002001500700001801520856004901538       2006                        eng d00aFunctional interaction of VEGF-C and VEGF-D with neuropilin receptors0 aFunctional interaction of VEGFC and VEGFD with neuropilin recept  c2006/Jul/  a1462 - 720 v203 aLymphatic vascular development is regulated by vascular endothelial growth factor receptor-3 (VEGFR-3), which is activated by its ligands VEGF-C and VEGF-D. Neuropilin-2 (NP2), known to be involved in neuronal development, has also been implicated to play a role in lymphangiogenesis. We aimed to elucidate the mechanism by which NP2 is involved in lymphatic endothelial cell signaling. By in vitro binding studies we found that both VEGF-C and VEGF-D interact with NP2, VEGF-C in a heparin-independent and VEGF-D in a heparin-dependent manner. We also mapped the domains of VEGF-C and NP2 required for their binding. The functional importance of the interaction of NP2 with the lymphangiogenic growth factors was demonstrated by cointernalization of NP2 along with VEGFR-3 in endocytic vesicles of lymphatic endothelial cells upon stimulation with VEGF-C or VEGF-D. NP2 also interacted with VEGFR-3 in coprecipitation studies. Our results show that NP2 is directly involved in an active signaling complex with the key regulators of lymphangiogenesis and thus suggest a mechanism by which NP2 functions in the development of the lymphatic vasculature.1 aKärpänen, Terhi1 aHeckman, Caroline, A1 aKeskitalo, Salla1 aJeltsch, Michael1 aOllila, Hanna1 aNeufeld, Gera1 aTamagnone, Luca1 aAlitalo, Kari  uhttp://view.ncbi.nlm.nih.gov/pubmed/16816121