Neuropilin-1 Is a Placenta Growth Factor-2 Receptor*
- Michal Migdal‡,
- Bernd Huppertz§,
- Shoshana Tessler‡,
- Amir Comforti‡,
- Masabumi Shibuya¶,
- Reuven Reich‖,
- Hanno Baumann§ and
- Gera Neufeld‡**
- From the ‡Department of Biology, Technion, Israel Institute of Technology, Haifa, 32000, Israel, the ‖Department of Pharmacology, Hebrew University of Jerusalem, Jerusalem, 91120 Israel,§Macromolecular Chemistry and Textile Chemistry, RWTH, Worringerweg 1, 52074, Aachen, Germany, and the ¶Department of Genetics, Institute of Medical Science, University of Tokyo, Minato-Ku, Tokyo 108, Japan
Abstract
Placenta growth factor (PlGF) belongs to the family of vascular endothelial growth factors (VEGFs). It binds to theflt-1 VEGF receptor but not to the KDR/flk-1receptor which is thought to mediate most of the angiogenic and proliferative effects of VEGF. Three PlGF isoforms are produced by alternative splicing. PlGF-1 and PlGF-3 differ from PlGF-2 since they lack the exon 6 encoded peptide which bestows upon PlGF-2 its heparin binding properties. Cross-linking experiments revealed that125I-PlGF-2 binds to two endothelial cell surface receptors in a heparin dependent fashion. The binding of 125I-PlGF-2 to these receptors was inhibited by an excess of PlGF-2 and by the 165-amino acid form of VEGF (VEGF165), but not at all by VEGF121 and very marginally if at all by PlGF-1. The apparent molecular weight and the binding characteristics of these receptors correspond to those of the recently identified VEGF165 specific receptor neuropilin-1, and we therefore conclude that neuropilin-1 is a receptor for PlGF-2. The binding of125I-PlGF-2 as well as the binding of125I-VEGF165 to these receptors was inhibited by a synthetic peptide derived from exon 6 of PlGF. Furthermore, the binding of 125I-PlGF-2, but not that of125I-VEGF165, was also inhibited by a synthetic peptide derived from exon 7 of PlGF. These observations indicate that the peptides encoded by these exons probably participate in the formation of the domain which mediates the binding of PlGF-2 to these receptors. We have also determined, using chemically modified heparin species, that the presence of sulfate moieties on the glucosamine-O-6 and on the iduronic acid-O-2 groups of heparin was required for the potentiation of125I-PlGF-2 binding to these receptors. To determine if PlGF-2 is able to induce biological responses that are not induced by PlGF-1, we compared the effects of PlGF-1 and PlGF-2 on the migration and proliferation of endothelial cells. Both PlGF forms induced migration of endothelial cells. However, there was no quantitative difference between the response to PlGF-2 and the response to PlGF-1. Furthermore, neither PlGF-1 nor PlGF-2 had any effect upon the proliferation of the endothelial cells.
Footnotes
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↵* This work was supported by the Wolfson Foundation and a grant from the Angiogenesis Research Center from the Israel Academy of Sciences (to G. N.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵** To whom correspondence should be addressed. Tel.: 972-4-8294216; Fax: 972-4-8225153; E-mail: gera{at}techunix.technion.ac.il.
- Abbreviations:
- PlGF
-
placental growth factor
- DSS
-
disuccinimidyl suberate
- KDR/Flk-1: tyrosine kinase VEGF receptor-2
-
flt-1, tyrosine kinase VEGF receptor-1
- HUVEC
-
human umbilical vein-derived endothelial cells
- VEGF
-
vascular endothelial growth factor
- VEGF165
-
165-amino acid form of vascular endothelial growth factor
- VEGF121
-
121-amino acid form of vascular endothelial growth factor
- HPLC
-
high performance liquid chromatography.
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- Received February 26, 1998.
- Revision received April 30, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
