title: Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6.
abstract: CD44v6, a member of the CD44 family of transmembrane glycoproteins is a co-receptor for two receptor tyrosine kinases (RTKs), Met and VEGFR-2 (vascular endothelial growth factor receptor 2). CD44v6 is not only required for the activation of these RTKs but also for signalling. In order to understand the role of CD44v6 in Met and VEGFR-2 activation and signalling we tested whether CD44v6 binds to their ligands, HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor), respectively. FACS analysis and cellular ELISA showed binding of HGF and VEGF only to cells expressing CD44v6. Direct binding of CD44v6 to HGF and VEGF was demonstrated in pull-down assays and the binding affinities were determined using MicroScale Thermophoresis, fluorescence correlation spectroscopy and fluorescence anisotropy. The binding affinity of CD44v6 to HGF is in the micromolar range in contrast with the high-affinity binding measured in the case of VEGF and CD44v6, which is in the nanomolar range. These data reveal a heparan sulfate-independent direct binding of CD44v6 to the ligands of Met and VEGFR-2 and suggest different roles of CD44v6 for these RTKs.
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Postfach 3640, 76021 Karlsruhe, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Volz
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Postfach 3640, 76021 Karlsruhe, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Koschut
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Postfach 3640, 76021 Karlsruhe, Germany amcure GmbH, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Matzke-Ogi
authors.affiliation: Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Dietz
authors.affiliation: Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany.
authors.forename: Christos
authors.initials: C
authors.lastname: Karathanasis
authors.affiliation: UMR 7213 CNRS, Laboratoire de Biophotonique et Pharmacologie Faculté de Pharmacie 74 route du Rhin, 67401 Illkirch, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Richert
authors.affiliation: Agilent Technologies, Hewlett-Packard-Straße 8, 76337 Waldbronn, Germany.
authors.forename: Moritz G
authors.initials: MG
authors.lastname: Wagner
authors.affiliation: UMR 7213 CNRS, Laboratoire de Biophotonique et Pharmacologie Faculté de Pharmacie 74 route du Rhin, 67401 Illkirch, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Mély
authors.affiliation: Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany.
authors.forename: Mike
authors.initials: M
authors.lastname: Heilemann
authors.affiliation: Department of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
authors.forename: Hartmut H
authors.initials: HH
authors.lastname: Niemann
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Postfach 3640, 76021 Karlsruhe, Germany veronique.orian-rousseau@kit.edu.
authors.forename: Véronique
authors.initials: V
authors.lastname: Orian-Rousseau
mesh_terms: D045744:Cell Line, Tumor; D057809:HEK293 Cells; D017228:Hepatocyte Growth Factor / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D011485:Protein Binding; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: C112697:CD44v6 antigen; C066855:HGF protein, human; D018960:Hyaluronan Receptors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D017228:Hepatocyte Growth Factor; C000588866:KDR protein, human; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met; D040301:Vascular Endothelial Growth Factor Receptor-2
keywords: CD44s; CD44v6; HGF; Met; VEGF; binding affinity