title: Rhodocetin-αβ-induced neuropilin-1-cMet association triggers restructuring of matrix contacts in endothelial cells.
abstract: OBJECTIVE
  The snake venom component rhodocetin-αβ (RCαβ) stimulates endothelial cell motility in an α2β1 integrin-independent manner. We aimed to elucidate its cellular and molecular mechanisms.
  
  
  RESULTS
  We identified neuropilin-1 (Nrp1) as a novel target of RCαβ by protein-chemical methods. RCαβ and vascular endothelial growth factor (VEGF)-A avidly bind to Nrp1. Instead of acting as VEGF receptor 2 coreceptor, Nrp1 associates upon RCαβ treatment with cMet. Furthermore, cell-based ELISAs and kinase inhibitor studies showed that RCαβ induces phosphorylation of tyrosines 1234/1235 [corrected] and thus activation of cMet. Consequently, paxillin is phosphorylated at Y31, which is redistributed from streak-like focal adhesions to spot-like focal contacts at the cell perimeter, along with α2β1 integrin, thereby regulating cell-matrix interactions. Cortactin is abundant in the cell perimeter, where it is involved in the branching of the cortical actin network of lamellipodia, whereas tensile force-bearing actin stress fibers radiating from focal adhesions disappear together with zyxin, a focal adhesion marker, on RCαβ treatment.
  
  
  CONCLUSIONS
  Our data demonstrate that (1) Nrp1 is a novel target for venom components, such as RCαβ; (2) Nrp1 coupled to cMet regulates the type of cell-matrix interactions in a manner involving paxillin phosphorylation; and (3) altered cell-matrix interactions determine endothelial cell migration and cellular force management.
authors.affiliation: Center for Molecular Medicine, Vascular Matrix Biology, Excellence Cluster Cardio-Pulmonary System, Frankfurt University Hospital, Frankfurt, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Niland
authors.forename: Bartosz
authors.initials: B
authors.lastname: Ditkowski
authors.forename: Désirée
authors.initials: D
authors.lastname: Parrandier
authors.forename: Lise
authors.initials: L
authors.lastname: Roth
authors.forename: Hellmut
authors.initials: H
authors.lastname: Augustin
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Eble
mesh_terms: D001667:Binding, Competitive; D002465:Cell Movement / Q000187:drug effects*; D021982:Cell-Matrix Junctions / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D051356:Cortactin / Q000378:metabolism; D003435:Crotalid Venoms / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D038982:Integrin alpha2beta1 / Q000378:metabolism; D039942:Neuropilin-1 / Q000378:metabolism*; D051419:Paxillin / Q000378:metabolism; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D022502:Stress Fibers / Q000378:metabolism; D014443:Tyrosine; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D060589:Zyxin / Q000378:metabolism
chemical_list: C495868:CTTN protein, human; D051356:Cortactin; D003435:Crotalid Venoms; D038982:Integrin alpha2beta1; C496061:PXN protein, human; D051419:Paxillin; D047428:Protein Kinase Inhibitors; D042461:Vascular Endothelial Growth Factor A; C092842:ZYX protein, human; D060589:Zyxin; C119730:rhodocetin; D039942:Neuropilin-1; D014443:Tyrosine; D019859:Proto-Oncogene Proteins c-met