Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6. Issue 4 (7th August 2015)

• Record Type: Journal Article
• Authors: Volz, Yvonne; Koschut, David; Matzke-Ogi, Alexandra; Dietz, Marina S.; Karathanasis, Christos; Richert, Ludovic; Wagner, Moritz G.; Mély, Yves; Heilemann, Mike; Niemann, Hartmut H.; Orian-Rousseau, Véronique
• Is Part Of: Bioscience reports. Volume 35:Issue 4(2015)
• Publication Date: 2015-08-07
• Subjects: binding affinity -- CD44s -- CD44v6 -- HGF -- Met -- VEGF; Molecular biology -- Periodicals; Cytology -- Periodicals; 572.8
• DOI: 10.1042/BSR20150093
• Languages: English
• ISSNs: 0144-8463

Abstract

Abstract : CD44v6 is a co-receptor for the receptor tyrosine kinases Met and VEGFR-2 (vascular endothelial growth factor receptor 2). The binding of these RTKs (receptor tyrosine kinases) to their ligands on cells requires CD44v6. Pull-downs assays show direct binding between these entities. Binding affinities were measured by several biophysical methods. 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.