6533b7dcfe1ef96bd127298d

RESEARCH PRODUCT

Identification of the integrin-binding site on coagulation factor VIIa required for proangiogenic PAR2 signaling.

Andrea S. RothmeierSagarika ChakrabartyHenrik ØStergaardBarbara M. MuellerEnbo LiuJennifer DisseWolfram RufWolfram Ruf

subject

0301 basic medicineCell signalingImmunologyIntegrinNeovascularization PhysiologicFactor VIIa030204 cardiovascular system & hematologyBiochemistryThromboplastinThrombosis and Hemostasis03 medical and health sciencesTissue factorMice0302 clinical medicineAnimalsHumansReceptor PAR-2Protein Interaction Domains and MotifsProtein Interaction MapsProtein kinase ACells CulturedIntegrin bindingBinding SitesbiologyChemistryIntegrin beta1Cell BiologyHematologyCell biologyCrosstalk (biology)030104 developmental biologyADP-Ribosylation Factor 6biology.proteinNIH 3T3 CellsPhosphorylationSignal transductionProtein BindingSignal Transduction

description

The tissue factor (TF) pathway serves both hemostasis and cell signaling, but how cells control these divergent functions of TF remains incompletely understood. TF is the receptor and scaffold of coagulation proteases cleaving protease-activated receptor 2 (PAR2) that plays pivotal roles in angiogenesis and tumor development. Here we demonstrate that coagulation factor VIIa (FVIIa) elicits TF cytoplasmic domain-dependent proangiogenic cell signaling independent of the alternative PAR2 activator matriptase. We identify a Lys-Gly-Glu (KGE) integrin-binding motif in the FVIIa protease domain that is required for association of the TF-FVIIa complex with the active conformer of integrin β1. A point mutation in this motif markedly reduces TF-FVIIa association with integrins, attenuates integrin translocation into early endosomes, and reduces delayed mitogen-activated protein kinase phosphorylation required for the induction of proangiogenic cytokines. Pharmacologic or genetic blockade of the small GTPase ADP-ribosylation factor 6 (arf6) that regulates integrin trafficking increases availability of TF-FVIIa with procoagulant activity on the cell surface, while inhibiting TF-FVIIa signaling that leads to proangiogenic cytokine expression and tumor cell migration. These experiments delineate the structural basis for the crosstalk of the TF-FVIIa complex with integrin trafficking and suggest a crucial role for endosomal PAR2 signaling in pathways of tissue repair and tumor biology.

10.1182/blood-2017-02-768218https://pubmed.ncbi.nlm.nih.gov/29246902