Determination of cell adhesion sites of neuropilin-1.
Neuropilin-1 is a type 1 membrane protein with three distinct functions. First, it can mediate cell adhesion via a heterophilic molecular interaction. Second, in neuronal cells, neuropilin-1 binds the class 3 semaphorins, which are neuronal chemorepellents, and plays a role in the directional guidance of axons. Neuropilin-1 is expected to form complexes with the plexinA subfamily members and mediate the semaphorin-elicited inhibitory signals into neurons. Third, in endothelial cells, neuropilin-1 binds a potent endothelial cell mitogen, vascular endothelial growth factor (VEGF)(165), and regulates vessel formation. Though the binding sites in neuropilin-1 for the class 3 semaphorins and VEGF(165) have been analyzed, the sites involved in cell adhesion activity of the molecule have not been identified. In this study, we produced a variety of mutant neuropilin-1s and tested their cell adhesion activity. We showed that the b1 and b2 domains within the extracellular segment of neuropilin-1 were required for the cell adhesion activity, and peptides with an 18-amino acid stretch in the b1 and b2 domains were sufficient to induce the cell adhesion activity. In addition, we demonstrated that the cell adhesion ligands for neuropilin-1 were proteins and distributed in embryonic mesenchymal cells but distinct from the class 3 semaphorins, VEGF, or plexins.
Shimizu
M
M
Group of Developmental Neurobiology, Division of Biological Science, Nagoya University Graduate School of Science, Chikusa-ku, Nagoya 464-8602, USA.
Murakami
Y
Y
Suto
F
F
Fujisawa
H
H
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002448:Cell Adhesion; D002449:Cell Aggregation; D002460:Cell Line; D002645:Chickens; D017124:Conserved Sequence; D016228:Endothelial Growth Factors / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007624:KB Cells; D007739:L Cells; D008222:Lymphokines / Q000378:metabolism* / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism* / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D039942:Neuropilin-1; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014981:Xenopus
D016228:Endothelial Growth Factors; D008222:Lymphokines; D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D039942:Neuropilin-1